Pharmacological Evaluation and Preparation of Nonsteroidal Anti-Inflammatory Drugs Containing an N-Acyl Hydrazone Subunit

PubMed Central

de Melo, Thais Regina Ferreira; Chelucci, Rafael Consolin; Pires, Maria Elisa Lopes; Dutra, Luiz Antonio; Barbieri, Karina Pereira; Bosquesi, Priscila Longhin; Trossini, Gustavo Henrique Goulart; Chung, Man Chin; dos Santos, Jean Leandro

2014-01-01

A series of anti-inflammatory derivatives containing an N-acyl hydrazone subunit (4a–e) were synthesized and characterized. Docking studies were performed that suggest that compounds 4a–e bind to cyclooxygenase (COX)-1 and COX-2 isoforms, but with higher affinity for COX-2. The compounds display similar anti-inflammatory activities in vivo, although compound 4c is the most effective compound for inhibiting rat paw edema, with a reduction in the extent of inflammation of 35.9% and 52.8% at 2 and 4 h, respectively. The anti-inflammatory activity of N-acyl hydrazone derivatives was inferior to their respective parent drugs, except for compound 4c after 5 h. Ulcerogenic studies revealed that compounds 4a–e are less gastrotoxic than the respective parent drug. Compounds 4b–e demonstrated mucosal damage comparable to celecoxib. The in vivo analgesic activities of the compounds are higher than the respective parent drug for compounds 4a–b and 4d–e. Compound 4a was more active than dipyrone in reducing acetic-acid-induced abdominal constrictions. Our results indicate that compounds 4a–e are anti-inflammatory and analgesic compounds with reduced gastrotoxicity compared to their respective parent non-steroidal anti-inflammatory drugs. PMID:24714090

Multiple C-H Bond Activations and Ring-Opening C-S Bond Cleavage of Thiophene by Dirhenium Carbonyl Complexes.

PubMed

Adams, Richard D; Dhull, Poonam; Tedder, Jonathan D

2018-06-14

The reaction of Re 2 (CO) 8 (μ-C 6 H 5 )(μ-H) (1) with thiophene in CH 2 Cl 2 at 40 °C yielded the new compound Re 2 (CO) 8 (μ-η 2 -SC 4 H 3 )(μ-H) (2), which contains a bridging σ-π-coordinated thienyl ligand formed by the activation of the C-H bond at the 2 position of the thiophene. Compound 2 exhibits dynamical activity on the NMR time scale involving rearrangements of the bridging thienyl ligand. The reaction of compound 2 with a second 1 equiv of 1 at 45 °C yielded the doubly metalated product [Re 2 (CO) 8 (μ-H)] 2 (μ-η 2 -2,3-μ-η 2 -4,5-C 4 H 2 S) (3), formed by the activation of the C-H bond at the 5 position of the thienyl ligand in 2. Heating 3 in a hexane solvent to reflux transformed it into the ring-opened compound Re(CO) 4 [μ-η 5 -η 2 -SCC(H)C(H)C(H)][Re(CO) 3 ][Re 2 (CO) 8 (μ-H)] (4) by the loss of one CO ligand. Compound 4 contains a doubly metalated 1-thiapentadienyl ligand formed by the cleavage of one of the C-S bonds. When heated to reflux (125 °C) in an octane solvent in the presence of H 2 O, the new compound Re(CO) 4 [η 5 -μ-η 2 -SC(H)C(H)C(H)C(H)]Re(CO) 3 (5) was obtained by cleavage of the Re 2 (CO) 8 (μ-H) group from 4 with formation of the known coproduct [Re(CO) 3 (μ 3 -OH)] 4 . All new products were characterized by single-crystal X-ray diffraction analyses.

Radiocarbon evidence for a naturally produced, bioaccumulating halogenated organic compound.

PubMed

Reddy, Christopher M; Xu, Li; O'Neil, Gregory W; Nelson, Robert K; Eglinton, Timothy I; Faulkner, D John; Norstrom, Ross; Ross, Peter S; Tittlemier, Sheryl A

2004-04-01

Halogenated organic compounds (HOCs) such as 1,1'-dimethyl-3,3',4,4'-tetrabromo-5,5'-dichloro-2,2'-bipyrrole (DBP-Br4Cl2) and heptachloro-1'-methyl-1,2'-bipyrrole (Q1) have been detected worldwide, sometimes at high levels in Antarctic air, seabird eggs, the blubber of marine mammals, and, most notably, even human milk. To date, it has been difficult to determine whether these compounds are natural products or derived from industrial synthesis. Molecular-level 14C analysis of these compounds is particularly appealing because most industrial compounds are manufactured from petrochemicals (14C-free) and natural compounds should have "modern" or "contemporary" 14C levels. To investigate the source of DBP-Br4Cl2, we isolated 600 microg of this compound (150 microg of carbon) from marine animal extracts by employing gel permeation chromatography, Florisil column chromatography, and two-dimensional preparative capillary gas chromatography. The purified DBP-Br4Cl2 was split into two samples (75 microg of carbon each) and analyzed by accelerator mass spectrometry for 14C content. The delta14C values were -449 percent per thousand and -467 percent per thousand, corresponding to conventional 14C ages of 4740 and 5000 years before present (BP), respectively. The presence of detectable 14C in the DBP-Br4Cl2 strongly points to at least a natural or biogenic source. However, these delta14C values for DBP-Br4Cl2 are more depleted than expected for a recently synthesized natural product. Several explanations are discussed, but additional samples

Synthesis, Antiinflammatory and Antimicrobial Activity of Some New 1-(3-Phenyl-3,4-Dihydro-2H-1,3-Benzoxazin-6-yl)-Ethanone Derivatives.

PubMed

Akhter, Mymoona; Husain, A; Akhter, N; Khan, M S Y

2011-01-01

Synthesis of title compounds (4a-j) was carried out by following aminomethylation Mannich reaction. Test compounds were effective in inhibiting edema induced by carrageenan. The percent inhibition obseved was in the range of 25-83.3%. Compound (4c, e, h and j) were also tested for analgesic effect and showed percent protection ranging between 57-65%. All the synthesized compounds were active against E. coli and S. aureus but only compounds (4 b, c, e, i and j) were active against B. subtilis. All these compound were also found active against A. niger. Compound 4j was the most active compound with 83.3% inhibition of edema, 65.35% percent protection and inhibited all the three bacterial strains.

Three closely related 4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridines: synthesis, molecular conformations and hydrogen bonding in zero, one and two dimensions.

PubMed

Sagar, Belakavadi K; Harsha, Kachigere B; Yathirajan, Hemmige S; Rangappa, Kanchugarakoppal S; Rathore, Ravindranath S; Glidewell, Christopher

2017-03-01

In each of 1-(4-fluorophenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C 21 H 19 F 4 N 3 O 2 S, (I), 1-(4-chlorophenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C 21 H 19 ClF 3 N 3 O 2 S, (II), and 1-(3-methylphenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C 22 H 22 F 3 N 3 O 2 S, (III), the reduced pyridine ring adopts a half-chair conformation with the methylsulfonyl substituent occupying an equatorial site. Although compounds (I) and (II) are not isostructural, having the space groups Pbca and P2 1 2 1 2 1 , respectively, their molecular conformations are very similar, but the conformation of compound (III) differs from those of (I) and (II) in the relative orientation of the N-benzyl and methylsulfonyl substituents. In compounds (II) and (III), but not in (I), the trifluoromethyl groups are disordered over two sets of atomic sites. Molecules of (I) are linked into centrosymmetric dimers by C-H...π(arene) hydrogen bonds, molecules of (II) are linked by two C-H...O hydrogen bonds to form ribbons of R 3 3 (18) rings, which are themselves further linked by a C-Cl...π(arene) interaction, and a combination of C-H...O and C-H...π(arene) hydrogen bonds links the molecules of (III) into sheets. Comparisons are made with the structures of some related compounds.

Synthesis, characterization and molecular docking studies of substituted 4-coumarinylpyrano[2,3-c]pyrazole derivatives as potent antibacterial and anti-inflammatory agents.

PubMed

Chougala, Bahubali M; Samundeeswari, S; Holiyachi, Megharaja; Shastri, Lokesh A; Dodamani, Suneel; Jalalpure, Sunil; Dixit, Sheshagiri R; Joshi, Shrinivas D; Sunagar, Vinay A

2017-01-05

A green, eco-friendly and efficient protocol has been developed and synthesized a series of coumarin based pyrano[2,3-c]pyrazole derivatives (3) by multi-component reaction (MCR). Unexpected 3-coumarinyl-3-pyrazolylpropanoic acids (4) have been isolated by the reaction of compound (3) in acidic conditions. Further, intramolecular cyclization of compounds (4) leads to C 4 C 4 chromons (9) and these compounds were screened for their biological activities using array of techniques. Most of the compounds exhibited promising antibacterial activity, in particular Gram-positive bacteria. The anti-inflammatory assay was evaluated against protein denaturation as well as HRBC membrane stabilization methods and compounds exhibit excellent anti-inflammatory activity in both methods. Molecular docking study has been performed for all the synthesized compounds with S. aureus dihydropteroate synthetase (DHPS) and results obtained are quite promising. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

A series of 2, 4, 5-trisubstituted oxazole: Synthesis, characterization and DFT modelling

NASA Astrophysics Data System (ADS)

Kadam, Vinay S.; Shaikh, Saminaparwin G.; Patel, Arun L.

2016-06-01

A new series of 2,4,5-trisubstituted oxazole were synthesized with good yields using simple methodology. All the compounds were thoroughly characterized by IR, NMR (1H and 13C) and mass spectrometry and structures of 2-(4-butyloxyphenyl)-4,5-dimethyloxazole (5b) and 4,5-dimethyl-2-(4-(octyloxy)phenyl)oxazole(5e) were unambiguously determined by X-ray crystallography. Evidently, the crystal structures of these compounds showed C-H⋯N and C-H⋯O intermolecular interactions. The electronic structures of these compounds were also studied by DFT at B3LYP/6-311G ++ level of theory.

A chalcone showing positional disorder, two related diarylcyclohexenones showing enantiomeric disorder and a related hydroxyterphenyl, all derived from simple carbonyl precursors.

PubMed

Salian, Vinutha V; Narayana, Badiadka; Yathirajan, Hemmige S; Akkurt, Mehmet; Çelik, Ömer; Ersanlı, Cem Cüneyt; Glidewell, Christopher

2015-07-01

Four compounds are reported, all of which lie along a versatile reaction pathway which leads from simple carbonyl compounds to terphenyls. (2E)-1-(2,4-Dichlorophenyl)-3- [4-(prop-1-en-2-yl)phenyl]prop-2-en-1-one, C18H14Cl2O, (I), prepared from 4-(prop-1-en-2-yl)benzaldehyde and 2,4-dichloroacetophenone, exhibits disorder over two sets of atomic sites having occupancies of 0.664 (6) and 0.336 (6). The related chalcone (2E)-3-(4-chlorophenyl)-1-(4-fluorophenyl)prop-2-en-1-one reacts with acetone to produce (5RS)-3-(4-chlorophenyl)-5-[4-(propan-2-yl)phenyl]cyclohex-2-en-1-one, C21H21ClO, (II), which exhibits enantiomeric disorder with occupancies at the reference site of 0.662 (4) and 0.338 (4) for the (5R) and (5S) forms; the same chalcone reacts with methyl 3-oxobutanoate to give methyl (1RS,6SR)-4-(4-chlorophenyl)-6-[4-(propan-2-yl)phenyl]-2-oxocyclohex-3-ene-1-carboxylate, C23H23ClO3, (III), where the reference site contains both (1R,6S) and (1S,6R) forms with occupancies of 0.923 (3) and 0.077 (3), respectively. Oxidation, using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, of ethyl (1RS,6SR)-6-(4-bromophenyl)-4-(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate, prepared in a similar manner to (II) and (III), produces ethyl 4''-bromo-4-fluoro-5'-hydroxy-1,1':3',1''-terphenyl-4'-carboxylate, C21H16BrFO3, (IV), which crystallizes with Z' = 2 in the space group P-1. There are no significant intermolecular interactions in the structures of compounds (I) and (II), but for the major disorder component of compound (III), the molecules are linked into sheets by a combination of C-H...O and C-H...π(arene) hydrogen bonds. The two independent molecules of compound (IV) form two different centrosymmetric dimers, one built from inversion-related pairs of C-H...O hydrogen bonds and the other from inversion-related pairs of C-H...π(arene) hydrogen bonds. Comparisons are made with related compounds.

Synthesis, Antiinflammatory and Antimicrobial Activity of Some New 1-(3-Phenyl-3,4-Dihydro-2H-1,3-Benzoxazin-6-yl)-Ethanone Derivatives

PubMed Central

Akhter, Mymoona; Husain, A.; Akhter, N.; Khan, M. S. Y

2011-01-01

Synthesis of title compounds (4a-j) was carried out by following aminomethylation Mannich reaction. Test compounds were effective in inhibiting edema induced by carrageenan. The percent inhibition obseved was in the range of 25-83.3%. Compound (4c, e, h and j) were also tested for analgesic effect and showed percent protection ranging between 57-65%. All the synthesized compounds were active against E. coli and S. aureus but only compounds (4 b, c, e, i and j) were active against B. subtilis. All these compound were also found active against A. niger. Compound 4j was the most active compound with 83.3% inhibition of edema, 65.35% percent protection and inhibited all the three bacterial strains. PMID:22131632

Synthesis and anticonvulsant activity of some substituted 1,2,4-thiadiazoles.

PubMed

Gupta, Arun; Mishra, Pradeep; Pandeya, S N; Kashaw, Sushil K; Kashaw, Varsha; Stables, James P

2009-03-01

A series of new substituted 1,2,4-thiadiazoles were synthesized by appropriate route and screened for anticonvulsant, neurotoxic and sedative-hypnotic activity. The structures of the synthesized compounds were confirmed by IR spectroscopy, (13)C NMR and elemental (nitrogen and sulphur) analysis. After i.p. injection of the compounds to mice or rate at doses of 30, 100, and 300 mg/kg, body weights were examined in the maximal electroshock-induced seizures (MES) and subcutaneous pentylenetetrazole (scPTZ)-induced seizure models after 0.5 and 4 h. Rotorod method and phenobarbitone-induced hypnosis potentiation study were employed to examine neurotoxicity and sedative-hypnotic activity, respectively. All the compounds except 4g showed protection against MES screen after 0.5 h. Compounds 3a-c, 4a-c were active at 100 mg/kg dose i.p., whereas remaining compounds showed activity at 300 mg/kg. All 14 compounds except 3g showed neurotoxicity at 100 and 300 mg/kg after 0.5 h. Compounds 3b and 4b showed NT after 4 h. Two compounds 3b and 4g showed significant (p<0.05) percentage increase in sleeping time i.e. 67% and 59%, respectively. It may be concluded that the synthesized compounds were potent against MES-induced seizures than ScPTZ induced and showed low potency as sedative-hypnotic agent which is advantageous.

Design and syntheses of hybrid metal–organic materials based on K{sub 3}[M(C{sub 2}O{sub 4}){sub 3}]·3H{sub 2}O [M(III)=Fe, Al, Cr] metallotectons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Yayong; Zong, Yingxia; Ma, Haoran

2016-05-15

By using K{sub 3}[M(C{sub 2}O{sub 4}){sub 3}]·3H{sub 2}O [M(III)=Fe, Al, Cr] (C{sub 2}O{sub 4}{sup 2−}=oxalate) metallotectons as the starting material, we have synthesized eight novel complexes with formulas [{Fe(C_2O_4)_2(H_2O)_2}{sub 2}]·(H–L{sub 1}){sub 2}·H{sub 2}O 1, [Fe(C{sub 2}O{sub 4})Cl{sub 2}]·(H{sub 2}–L{sub 2}){sub 0.5}·(L{sub 2}){sub 0.5}·H{sub 2}O 2, [{Fe(C_2O_4)_1_._5Cl_2}{sub 2}]·(H–L{sub 3}){sub 4}3, [Fe{sub 2}(C{sub 2}O{sub 4})Cl{sub 8}]·(H{sub 2}–L{sub 4}){sub 2}·2H{sub 2}O 4, K[Al(C{sub 2}O{sub 4}){sub 3}]·(H{sub 2}–L{sub 5})·2H{sub 2}O 5, K[Al(C{sub 2}O{sub 4}){sub 3}]·(H–L{sub 6}){sub 2}·2H{sub 2}O 6, K[Cr(C{sub 2}O{sub 4}){sub 3}]·2H{sub 2}O 7, Na[Fe(C{sub 2}O{sub 4}){sub 3}]·(H–L{sub 6}){sub 2}·2H{sub 2}O 8 (with L{sub 1}=4-dimethylaminopyridine, L{sub 2}=2,3,5,6-tetramethylpyrazine, L{sub 3}=2-aminobenzimidazole, L{sub 4}=1,4-bis-(1H-imidazol-1-yl)benzene, L{sub 5}=1,4-bis((2-methylimidazol-1-yl)methyl)benzene,more » L{sub 6}=2-methylbenzimidazole). Their structures have been determined by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra and thermogravimetric analyses. Compound 3 is a 2D H-bonded supramolecular architecture. Others are 3D supramolecular structures. Compound 1 shows a [Fe(C{sub 2}O{sub 4}){sub 2}(H{sub 2}O){sub 2}]{sup −} unit and 3D antionic H-bonded framework. Compound 2 features a [Fe(C{sub 2}O{sub 4})Cl{sub 2}]{sup -} anion and 1D iron-oxalate-iron chain. Compound 3 features a [Fe{sub 2}(C{sub 2}O{sub 4}){sub 3}Cl{sub 4}]{sup 4−} unit. Compound 4 features distinct [Fe{sub 2}(C{sub 2}O{sub 4})Cl{sub 8}]{sup 4−} units, which are mutual linked by water molecules to generated a 2D H-bonded network. Compound 5 features infinite ladder-like chains constructed by [Al(C{sub 2}O{sub 4}){sub 3}]{sup 3−} units and K{sup +} cations. The 1D chains are further extended into 3D antionic H-bonded framework through O–H···O H-bonds. Compounds 6–8 show 2D [KAl(C{sub 2}O{sub 4}){sub 3}]{sup 2−} layer, [KCr(C{sub 2}O{sub 4}){sub 3}]{sup 2−} layer and [NaFe(C{sub 2}O{sub 4}){sub 3}]{sup 2−} layer, respectively. - Graphical abstract: We report here eight novel complexes by using [M(C{sub 2}O{sub 4}){sub 3}]{sup 3−} [M(III)=Fe, Al, Cr] metallotectons as the starting materials. These complexes show supramolecular architectures bonded by charge-assisted hydrogen bonds.« less

Synthesis and structure-activity relationship of di-(3, 8-diazabicyclo[3.2.1]octane) diquaternary ammonium salts as unique analgesics.

PubMed

Liu, Hong; Cheng, Tie-Ming; Zhang, Hong-Mei; Li, Run-Tao

2003-11-01

Based on the structure characteristics of the lead compounds, 1, 1' octanedioyl-4, 4'-dimethyl-4, 4'-dibenzyl dipiperazinium dibromide (2) and 3, 8-disubstituted-3, 8-diazabicyclo [3.2.1]octanes (DBO), di-(3, 8-diazabicyclo [3.2.1]octane) diquaternary ammonium salts 3 a-c were designed and synthesized through a highly practical procedure. Target compounds 3 a-c and the hydrochloride salts of their precursors 10 a-c were evaluated for their in vivo analgesic and sedative activities. Interestingly, the introduction of an endoethylenic bridge in the piperazine of lead compound 2 causes loss of the analgesic activity and increases the toxicity dramatically. This result shows that the flexible conformation of piperazine in compound 2 is favorable for interaction with the receptor, and the quaternization of compounds 10 a-c is the main reason for the toxicity increase.

Phase equilibrium relations in the binary systems LiPO 3CeP 3O 9 and NaPO 3CeP 3O 9

NASA Astrophysics Data System (ADS)

Rzaigui, Mohamed; Ariguib, Najia Kbir

1981-10-01

The LiPO 3CeP 3O 9 and NaPO 3CeP 3O 9 systems have been investigated for the first time by DTA, X-ray diffraction, and infrared spectroscopy. Each system forms a single 1:1 compound. LiCe(PO 3) 4 melts in a peritectic reaction at 980°C. NaCe(PO 3) 4 melts incongruently, too, at 865°C. These compounds have a monoclinic unit cell with the parameters: a = 16.415(6), b = 7,042(6), c = 9.772(7)Å; β = 126.03(5)°; Z = 4; space group {C 2}/{c} for LiCe (PO 3) 4; and a = 9.981(4), b = 13.129(6), c = 7.226(5) Å, β = 89.93(4)°, Z = 4, space group {P2 1}/{n} for NaCe(PO 3) 4. It is established that both compounds are mixed polyphosphates with chain structure of the type | MIIMIIIII (PO 3) 4| ∞MII: alkali metal, MIIIII: rare earth.

Synthesis and Crystal and Electronic Structures of the Dinuclear Platinum Compounds [PEtPh(3)](2)[Pt(2)(&mgr;-PPh(2))(2)(C(6)F(5))(4)] and [Pt(2)(&mgr;-PPh(2))(2)(C(6)F(5))(4)]: A Computational Study by Density Functional Theory.

PubMed

Alonso, Ester; Casas, José M.; Cotton, F. Albert; Feng, Xuejung; Forniés, Juan; Fortuño, Consuelo; Tomas, Milagros

1999-11-01

The electrolytic behavior of the dinuclear complexes [NBu(4)](2)[MM'(&mgr;-PPh(2))(2)(C(6)F(5))(4)] (M = M' = Pt (1), Pd (1a); M = Pt, M' = Pd (1b)) has been studied, showing electrochemically irreversible oxidation and related reduction processes. The chemical oxidation of the binuclear compound for M = M' = Pt, results in the formation of the binuclear Pt(III) compound [Pt(2)(&mgr;-PPh(2))(2)(C(6)F(5))(4)]. The crystal structure analysis of both complexes has been carried out, showing very similar structures with similar Pt-C and Pt-P distances and analogous skeletons. However the Pt-Pt distances are very different, 3.621(1) Å for the Pt(II) compound and 2.7245(7) Å for the Pt(III) derivative (as are the parameters geometrically related to this Pt-Pt distance), suggesting that, in the Pt(III) compound, there is a strong Pt-Pt bond. Results of DFT calculations on [Pt(2)(&mgr;-PH(2))(2)(C(6)F(5))(4)](n)()(-) (n = 2, 0) agree very well with the crystallographic data and indicate that, in the Pt(III) compound, there is approximately a single sigma bond between the metal atoms.

Sustainable metal alkynyl chemistry: 3d metals and polyaza macrocyclic ligands.

PubMed

Ren, Tong

2016-02-25

We describe the chemistry of 3d metal alkynyls based on polyaza macrocyclic ligands, an emerging area of alkynyl chemistry that has previously been dominated by 4d and 5d metals with soft ligands. The abundance of 3d metals and low cost of tetraazacyclotetradecane ligands make these compounds more affordable, sustainable alternatives to metal alkynyls based on precious metals. Taking advantage of the rich variety of starting materials available in the literature, trans-[M(cyclam)(C2R)2]X (cyclam = 1,4,8,11-tetraazacyclotetradecane) compounds have been prepared from the reactions between [M(cyclam)X2]X (M = Cr, Fe and Co; X = Cl or OTf) and LiC2R. With [Co(cyclam)Cl2](+), both the {trans-[Co(cyclam)Cl]2(μ-(C≡C)n)}(2+) and trans-[Co(cyclam)(C2R)Cl](+) compounds have been prepared by a dehydrohalogenation reaction. The latter compounds undergo the second alkynylation reaction to afford dissymmetric trans-[Co(cyclam)(C2R)(C2R')](+) compounds. Similar alkynylation chemistry with complexes of the cyclam derivatives TMC (1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane) and HMC (5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) has been demonstrated in studies of [Ni(TMC)(C2R)](+) and trans-/cis-[Cr(HMC)(C2R)2](+). Me3TACN (1,4,7-N,N',N''-trimethyl-1,4,7-triazacyclononane) is also a supporting ligand that has been observed in transition metal alkynyls. The trans-[M(cyclam)(C2D)(C2A)](+) compounds (D = donor chromophore, A = acceptor chromophore) are excellent candidates for probing photoinduced electron transfer and related photophysical and photochemical processes. 3d Metal ions are often in high-spin ground states, which make these alkynyl compounds promising building blocks for magnetic materials.

[Cochinchinenin--a new chalcone dimer from the Chinese dragon blood].

PubMed

Zhou, Z H; Wang, J L; Yang, C R

2001-03-01

To study the active constituents of Dracaena cochinchinensis (Lour.) S.C. Chen. in the commercial dragon blood. Various column chromatographies with Sephadex L-20 gel, MCI gel and silica gel were employed for the isolation and purification. The structures of compounds were elucidated by spectral analysis. Nine chalcones were isolated from the commercial dragon's blood which was made of D. cochinchinensis (Lour.) S.C. Chen.. By means of spectral data, they were identified as 1-[5-(2,4,4'-trihydroxydihydrochalconyl)]-1- (p-hydroxyphenyl)-3-(2-methoxy-4-hydroxy-phenyl)-propane (1), 2'-methoxysocotrin-5'-ol (2), socotrin-4'-ol (3), 2-methoxy-4, 4'-dihydroxydihydrochalcone (4), 2, 4, 4'-trihydroxy-dihydrochalcone (5), 2, 4, 4'-trihydroxy-6-methoxydihydrochalcone (6), 2', 4', 4-trihydroxychalcone (7), 2-methoxy-4, 4'-dihydroxychalcone (8) and 2'-methoxy-4', 4-dihydroxychalcone (9). Compound 1 is a new chalcone dimer and named as cochinchinenin. Compounds 2-9 were isolated from D. cochinchinensis (Lour.) S.C. Chen. for the first time.

Benzofuranyl Esters: Synthesis, Crystal Structure Determination, Antimicrobial and Antioxidant Activities.

PubMed

Kumar, C S Chidan; Then, Li Yee; Chia, Tze Shyang; Chandraju, Siddegowda; Win, Yip-Foo; Sulaiman, Shaida Fariza; Hashim, Nurul Shafiqah; Ooi, Kheng Leong; Quah, Ching Kheng; Fun, Hoong-Kun

2015-09-11

A series of five new 2-(1-benzofuran-2-yl)-2-oxoethyl 4-(un/substituted)benzoates 4(a-e), with the general formula of C₈H₅O(C=O)CH₂O(C=O)C₆H₄X, X = H, Cl, CH₃, OCH₃ or NO₂, was synthesized in high purity and good yield under mild conditions. The synthesized products 4(a-e) were characterized by FTIR, ¹H-, (13)C- and ¹H-(13)C HMQC NMR spectroscopic analysis and their 3D structures were confirmed by single-crystal X-ray diffraction studies. These compounds were screened for their antimicrobial and antioxidant activities. The tested compounds showed antimicrobial ability in the order of 4b < 4a < 4c < 4d < 4e and the highest potency with minimum inhibition concentration (MIC) value of 125 µg/mL was observed for 4e. The results of antioxidant activities revealed the highest activity for compound 4e (32.62% ± 1.34%) in diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, 4d (31.01% ± 4.35%) in ferric reducing antioxidant power (FRAP) assay and 4a (27.11% ± 1.06%) in metal chelating (MC) activity.

Beneficial Effect of the Nitric Oxide Donor Compound 3-(1,3-Dioxoisoindolin-2-yl)Benzyl Nitrate on Dysregulated Phosphodiesterase 5, NADPH Oxidase, and Nitrosative Stress in the Sickle Cell Mouse Penis: Implication for Priapism Treatment.

PubMed

Silva, Fábio H; Karakus, Serkan; Musicki, Biljana; Matsui, Hotaka; Bivalacqua, Trinity J; Dos Santos, Jean L; Costa, Fernando F; Burnett, Arthur L

2016-11-01

Patients with sickle cell disease (SCD) display priapism, and dysregulated nitric oxide (NO) pathway may contribute to this condition. However, current therapies offered for the prevention of priapism in SCD are few. The 3-(1,3-dioxoisoindolin-2-yl)benzyl nitrate (compound 4C) was synthesized through molecular hybridization of hydroxyurea and thalidomide, which displays an NO-donor property. This study aimed to evaluate the effects of compound 4C on functional and molecular alterations of erectile function in murine models that display low NO bioavailability, SCD transgenic mice, and endothelial NO synthase and neuronal NO synthase double gene-deficient (dNOS -/ ) mice, focusing on the dysregulated NO-cGMP- phosphodiesterase type 5 (PDE5) pathway and oxidative stress in erectile tissue. Wild-type, SCD, and dNOS -/- mice were treated with compound 4C (100 μmol/kg/d, 3 weeks). Intracavernosal pressure in anesthetized mice was evaluated. Corpus cavernosum tissue was dissected free and mounted in organ baths. SCD and dNOS -/- mice displayed a priapism phenotype, which was reversed by compound 4C treatment. Increased corpus cavernosum relaxant responses to acetylcholine and electrical-field stimulation were reduced by 4C in SCD mice. Likewise, increased sodium nitroprusside-induced relaxant responses were reduced by 4C in cavernosal tissue from SCD and dNOS -/- mice. Compound 4C reversed PDE5 protein expression and reduced protein expressions of reactive oxygen species markers, NADPH oxidase subunit gp91 phox , and 3-nitrotyrosine in penises from SCD and dNOS -/- mice. In conclusion, 3-week therapy with the NO donor 4C reversed the priapism in murine models that display lower NO bioavailability. NO donor compounds may constitute an additional strategy to prevent priapism in SCD. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Isoelectric point and adsorption activity of porous g-C3N4

NASA Astrophysics Data System (ADS)

Zhu, Bicheng; Xia, Pengfei; Ho, Wingkei; Yu, Jiaguo

2015-07-01

The isoelectric point (IEP) is an important physicochemical parameter of many compounds, such as oxides, hydroxides, and nitrides, and can contribute to estimation of the surface charges of compound particles at various pH conditions. In this work, three types of graphitic carbon nitrides (g-C3N4) were synthesized by directly heating melamine, thiourea, and urea. The prepared samples showed different microstructures and IEPs that influenced their adsorption activity. Differences in microstructure resulted from the various precursors used during synthesis. The IEPs of the obtained g-C3N4 were measured to be approximately 4-5, which is due to the equilibrium of chemical reactions between hydrogen ions, hydroxyl ions, and amine groups on the g-C3N4 surface. The IEP of g-C3N4 prepared from thiourea was lower than those of the corresponding samples prepared from melamine and urea. The adsorption activity of methylene blue on g-C3N4 prepared from urea and thiourea was excellent, which indicates that g-C3N4 is a promising adsorbent. This work provides a useful reference for choosing precursors with which to prepare g-C3N4 and combining g-C3N4 with other compounds in solution.

Synthesis and X-ray crystal structures of (Mo(CO)(Et{sub 2}PC{sub 2}H{sub 4}PEt{sub 2}){sub 2}){sub 2}({mu}-N{sub 2}) with an end-on bridging dinitrogen ligand and Mo(CO)(Bu{sup i}{sub 2}PC{sub 2}H{sub 4}PBu{sup i}{sub 2}){sub 2} containing an agostic Mo...H-C interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, X.L.; Kubas, G.J.; Burns, C.J.

1995-12-20

The compound formed by the reaction of trans-Mo(N{sub 2})(Et{sub 2}PC{sub 2}H{sub 4}PEt{sub 2}){sub 2} with ethyl acetate in refluxing toluene under argon has been formulated as the bridging dinitrogen complex (Mo(CO)(Et{sub 2}PC{sub 2}H{sub 4}PEt{sub 2}){sub 2}){sub 2}({mu}-N{sub 2}) (1), in contrast with the previously proposed formulation of Mo(CO)(Et{sub 2}PC{sub 2}H{sub 4}PEt{sub 2}){sub 2} (2). In refluxing p-xylene and under argon, compound 1 eliminates the bridging dinitrogen ligand to form the nitrogen-free compound 2. The reaction of trans-Mo(N{sub 2})(Bu{sup i}{sub 2}PC{sub 2}H{sub 4}PBu{sup i}{sub 2}){sub 2} (3). The molecular structures of compounds 1 and 3 have been determined by single-crystal X-raymore » diffraction studies. Compound 1 contains an end-on bridging dinitrogen ligand. Compound 3 attains a formal 18-electron configuration by virtue of an agostic Mo...H-C interaction between the molybdenum atom and an alphiatic {gamma}-C-H bond of the alkyldiphosphine ligand. On the basis of the agostic Mo...C and Mo...H distances, the agostic interaction in 3 appears to be stronger than that in the related compound Mo(CO)(Ph{sub 2}PC{sub 2}H{sub 4}PPh{sub 2}){sub 2} which involves an ortho aromatic C-H bond of the diphosphine ligand. Crystallographic data for 1: monoclinic, space group C2/c, a=24.270(2){angstrom}, b=44.233(4){angstrom}, c=20.378(2){angstrom}, {beta}=90.725(9){angstrom}, V=21875(3){angstrom}{sup 3}, Z=16, and R=0.048. Crystallographic data for 3: orthorhombic, space group Pna2{sub 1}, a=18.332(4){angstrom}, b=22.0664(4){angstrom}, c=10.589(2){angstrom}, V=4283(2){angstrom}{sup 3}, Z=4, and R=0.034.« less

Synthesis and pharmacological evaluation of pyrazolo[4,3-c]cinnoline derivatives as potential anti-inflammatory and antibacterial agents.

PubMed

Tonk, Rajiv Kumar; Bawa, Sandhya; Chawla, Gita; Deora, Girdhar Singh; Kumar, Suresh; Rathore, Vandana; Mulakayala, Naveen; Rajaram, Azad; Kalle, Arunasree M; Afzal, Obaid

2012-11-01

A series of pyrazolo[4,3-c]cinnoline derivatives was synthesized, characterized and evaluated for anti-inflammatory and antibacterial activity. Test compounds that exhibited good anti-inflammatory activity were further screened for their ulcerogenic and lipid peroxidation activity. Compounds 4d and 4l showed promising anti-inflammatory activity with reduced ulcerogenic and lipid peroxidation activity when compared to naproxen. Docking results of these two compounds with COX-2 (PDB ID: 1CX2) also exhibited a strong binding profile. Among the test derivatives, compound 4i displayed significant antibacterial property against gram-negative (Escherichia coli and Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus) bacteria. However, compound 4b emerged as the best dual anti-inflammatory-antibacterial agent in the present study. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

A Deuterium NMR Study of Bent-Core Liquid Crystals. 1; Synthesis and Characterization of Deuterium-Labeled Oxadiazole-Containing Liquid Crystals

NASA Technical Reports Server (NTRS)

Dingemans, Theo J.; Madsen, Louis A.; Samulski, Edward T.; Bushnell, Dennis M. (Technical Monitor)

2002-01-01

We have synthesized two deuterated boomerang-shaped liquid crystals based on 2,5-bis(4-hydroxyphenyl)-1,3,4-oxadiazole (ODBP). Deuterium was introduced in the rigid 2,5-diphenyl-1,3,4-oxadiazole core and in the aromatic ring of the terminal 4-dodecyloxyphenyl moiety using standard acid catalyzed deuterium exchange conditions. Both compounds, ([4,4'(1,3,4-oxadiazole-2,5-diyl-d4)] di-4-dodecyloxybenzoate: ODBP-d4-Ph-O-C12) and ([4,4'(1,3,4-oxadiazole-2,5-diyl)] di-4-dodecyloxy-benzoate-d4; ODBP-Ph-d4-O-C12) were investigated by nuclear magnetic resonance, optical microscopy and differential scanning calorimetry. The optical textures and thermal behavior of both compounds were found to be identical to the non-deuterated analog [4,4(1,3,4-oxadiazole-2,5-diyl)] di-4-dodecyloxybenzoate (ODBP-Ph-O-C12) which we reported earlier. These compounds exhibit behavior indicative of a biaxial nematic liquid crystal phase, which we hope to confirm using deuterium NMR spectroscopy in the next phase of this study.

Monodentate phosphine substitution in [Pd(κ3-dppf)(PR3)][BF4]2 (dppf = 1,1'-bis(diphenylphosphino)ferrocene) compounds.

PubMed

Cabrera, K D; Rowland, A T; Szarko, J M; Diaconescu, P L; Bezpalko, M W; Kassel, W S; Nataro, C

2017-05-02

The ligand 1,1'-bis(diphenylphosphino)ferrocene (dppf) is commonly employed in a variety of catalytic systems. There are a variety of coordination modes known for dppf, the least studied being the κ 3 coordination mode, in which both phosphorus atoms and the iron atom of dppf interact with another metal center. One such compound is the previously reported [Pd(κ 3 -dppf)(PPh 3 )] 2+ . A series of related compounds, [Pd(κ 3 -dppf)(P(p-C 6 H 4 R) 3 )] 2+ (R = OCH 3 , CH 3 , F and CF 3 ), has been synthesized and characterized. The X-ray crystal structure of [Pd(dppf)(P(p-C 6 H 4 F) 3 )][BF 4 ] 2 was determined. Electrochemical and computational studies indicate that the electron donor ability of the P(p-C 6 H 4 R) 3 ligands influences the properties of these compounds. Substitution reactions of the P(p-C 6 H 4 R) 3 ligands have been examined, and, in general, the more electron donating P(p-C 6 H 4 R) 3 ligands completely replace the less electron donating ones. The kinetics of the reaction of [Pd(κ 3 -dppf)(P(p-C 6 H 4 F) 3 )] 2+ with P(p-C 6 H 4 OCH 3 ) 3 indicate that the reaction proceeds through a dissociative mechanism, contrary to the associative substitutions prevalent in square planar palladium(ii) chemistry.

Construction of New Coordination Polymers from 4'-(2,4-disulfophenyl)- 3,2':6'3"-terpyridine: Polymorphism, pH-dependent syntheses, structures, and properties

NASA Astrophysics Data System (ADS)

Zhang, Li; Li, Chao-Jie; He, Jia-En; Chen, Yin-Yu; Zheng, Sheng-Run; Fan, Jun; Zhang, Wei-Guang

2016-01-01

Nine new coordination compounds, namely, [Co(HDSPTP)2(H2O)4]·4H2O (H2DSPTP=4'-(2,4-disulfophenyl)-3,2':6'3"-terpyridine, 1 and 2), {[Ni(DSPTP)(H2O)4]·3H2O}n (3), {[Cu(HDSPTP)2(H2O)3]·8H2O}n (4), {[Cu(HDSPTP)2(H2O)3]·6H2O}n (5), {[Cu(DSPTP)(H2O)2]·H2O}n (6), {[Zn(DSPTP)(H2O)2]·2H2O}n (7), {[Cd(DSPTP)(H2O)2]·2H2O}n (8), and [Ag2(DSPTP)(H2O)]n (9), were constructed based on a new ligand containing both terpyridyl and sulfo groups. The reactions of H2DSPTP with Co(NO3)2.6H2O resulted in two mononuclear complexes (compounds 1 and 2). They are polymorphisms that display different hydrogen bonding networks. They are selectively synthesized by altering the added alkalis. The reaction of H2DSPTP with Ni(NO3)2·6H2O resulted in a 1D "S-shaped" coordination chain (compound 3). The reactions of Cu(II) with H2DSPTP at different pH value resulted in the following three compounds: two kinds of 1D chains obtained at pH 3.0 and 4.0 for compounds 4 and 5, respectively, and a 3D framework based on binuclear ring units with 4-connected sra topology (Compound 6). The reactions of H2DSPTP with ds-block ions resulted in the following three compounds: a Zn(II) (compound 7) and a Cd(II) (compound 8) 3D frameworks with structures similar to that in compound 6, and a 3D framework based on tetranuclear Ag(I) SBUs with binodal (4,8)-connected flu type 3D framework topology. The structural diversity is mainly attributed to the rich coordination modes (from monodentate to μ7-mode) and conformations (cis-cis and cis-trans) of HDSPTP-/DSPTP2- ligands and the metal center and can be controllable synthesized by altering the alkalis, and pH value. Thermal stability of all compounds was performed, and the thermal behaviors of compounds 6 and 8 were further explored by PXRD. Compound 6 exhibits low thermal stability and undergo a crystalline-crystalline-amorphous phase transition as temperature increases from 25 °C to 200 °C, and show amorphous-crystalline phase transition when rehydrated. However, compound 8 exhibits high thermal stability above 500 °C. Its crystalline phase can retain above 300 °C and undergo a crystalline-crystalline phase transition as temperature increased to 400 °C, and transit back to compound 8 when rehydrated. Moreover, luminescence properties of compounds 7-9 were also investigated.

Experimental and molecular modeling investigation of isopropyl 4-(biphenyl-4-Yl)-2,6,6-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate

NASA Astrophysics Data System (ADS)

Yıldırım, Sema Öztürk; ćetin, Gökalp; Büyükmumcu, Zeki; Şimşek, Rahime; Şafak, Cihat; Butcher, Ray J.; Pekdur, Özlem Savaş

2018-02-01

The most important effect of 1,4-dihydropyridine (1,4-DHP) derivatives with various biological activities is to reduce the influx of extracellular Ca2+ ions. Because of this feature, many 1,4-DHP derivatives have been identified as potent calcium channel blockers and have been included in the treatment as antihypertensive agents. On the other hand, the biphenyl group is an important group in the molecule of biologically active compounds. The active compounds are obtained by introducing the biphenyl group into the structure of various compounds. In this study, the biphenyl group was introduced into the 1,4-DHP ring to reach to hexahydroquinoline (HHQ) derivative as an active calcium channel blocker compound. The structure of the compound was proved by IR, 1H-NMR, Mass spectroscopy, X-ray crystallography and elemental analysis. The cytotoxic properties of the compound has been determined, and biological activity assays continue. The crystal structure of C28H31NO3 was determined by single crystal X-ray diffraction: monoclinic, space group C c, a = 11.9713(3) Å, b = 18.7893(5) Å, c = 10.7358(3) Å, β = 102.411(4)°, Z = 4. The title molecule is twisted with the dihedral angle between two phenyl rings being 50.86(10)°. The optimized geometries of the title compound have been obtained employing DFT method. The calculated geometrical parameters were found to be in agreement with the experimental data.

Thiocyanate-Ligated Heterobimetallic {PtM} Lantern Complexes Including a Ferromagnetically Coupled 1D Coordination Polymer.

PubMed

Guillet, Jesse L; Bhowmick, Indrani; Shores, Matthew P; Daley, Christopher J A; Gembicky, Milan; Golen, James A; Rheingold, Arnold L; Doerrer, Linda H

2016-08-15

A series of heterobimetallic lantern complexes with the central unit {PtM(SAc)4(NCS)} have been prepared and thoroughly characterized. The {Na(15C5)}[PtM(SAc)4(NCS)] series, 1 (Co), 2 (Ni), 3 (Zn), are discrete compounds in the solid state, whereas the {Na(12C4)2)}[PtM(SAc)4(NCS)] series, 4 (Co), 5 (Ni), 6 (Zn), and 7 (Mn), are ion-separated species. Compound 7 is the first {PtMn} lantern of any bridging ligand (carboxylate, amide, etc.). Monomeric 1-7 have M(2+), necessitating counter cations that have been prepared as {(15C5)Na}(+) and {(12C4)2Na}(+) variants, none of which form extended structures. In contrast, neutral [PtCr(tba)4(NCS)]∞ 8 forms a coordination polymer of {PtCr}(+) units linked by (NCS)(-) in a zigzag chain. All eight compounds have been thoroughly characterized and analyzed in comparison to a previously reported family of compounds. Crystal structures are presented for compounds 1-6 and 8, and solution magnetic susceptibility measurements are presented for compounds 1, 2, 4, 5, and 7. Further structural analysis of dimerized {PtM} units reinforces the empirical observation that greater charge density along the Pt-M vector leads to more Pt···Pt interactions in the solid state. Four structural classes, one new, of {MPt}···{PtM} units are presented. Solid state magnetic characterization of 8 reveals a ferromagnetic interaction in the {PtCr(NCS)} chain between the Cr centers of J/kB = 1.7(4) K.

Semiconducting perovskites (2-XC6H4C2H4NH3)2SnI4 (X = F, Cl, Br): steric interaction between the organic and inorganic layers.

PubMed

Xu, Zhengtao; Mitzi, David B; Dimitrakopoulos, Christos D; Maxcy, Karen R

2003-03-24

Two new semiconducting hybrid perovskites based on 2-substituted phenethylammonium cations, (2-XC(6)H(4)C(2)H(4)NH(3))(2)SnI(4) (X = Br, Cl), are characterized and compared with the previously reported X = F compound, with a focus on the steric interaction between the organic and inorganic components. The crystal structure of (2-ClC(6)H(4)C(2)H(4)NH(3))(2)SnI(4) is solved in a disordered subcell [C2/m, a = 33.781(7) A, b = 6.178(1) A, c = 6.190(1) A, beta = 90.42(3)(o), and Z = 2]. The structure is similar to the known (2-FC(6)H(4)C(2)H(4)NH(3))(2)SnI(4) structure with regard to both the conformation of the organic cations and the bonding features of the inorganic sheet. The (2-BrC(6)H(4)C(2)H(4)NH(3))(2)SnI(4) system adopts a fully ordered monoclinic cell [P2(1)/c, a = 18.540(2) A, b = 8.3443(7) A, c = 8.7795(7) A, beta = 93.039(1)(o), and Z = 2]. The organic cation adopts the anti conformation, instead of the gauche conformation observed in the X = F and Cl compounds, apparently because of the need to accommodate the additional volume of the bromo group. The steric effect of the bromo group also impacts the perovskite sheet, causing notable distortions, such as a compressed Sn-I-Sn bond angle (148.7(o), as compared with the average values of 153.3 and 154.8(o) for the fluoro and chloro compounds, respectively). The optical absorption features a substantial blue shift (lowest exciton peak: 557 nm, 2.23 eV) relative to the spectra of the fluoro and chloro compounds (588 and 586 nm, respectively). Also presented are transport properties for thin-film field-effect transistors (TFTs) based on spin-coated films of the two hybrid semiconductors.

Studies on novel 4beta-[(4-substituted)-1,2,3-triazol-1-yl] podophyllotoxins as potential anticancer agents.

PubMed

Bhat, Bilal A; Reddy, P Bhaskar; Agrawal, Satyam Kumar; Saxena, A K; Kumar, H M Sampath; Qazi, G N

2008-10-01

A series of 4beta-[(4-substituted)-1,2,3-triazol-1-yl] podophyllotoxin congeners have been designed and synthesized with significant regioselectivity by employing Cu(I) catalyzed 1,3-dipolar cycloaddition reaction of C4beta-azido podophyllotoxin and C4beta-azido-4'-O-demethyl podophyllotoxin with N-prop-2-yn-1-ylanilines. These compounds were evaluated for anticancer activity against a panel of seven human cancer cell lines. It was interesting to note that all the compounds exhibited promising activity especially against SF-295 (CNS), HCT-15 (colon) and 502713 (colon) cell lines. Compound 11e was found to be the most promising in this study.

Crystal Structures and Thermal Properties of Two Transition-Metal Compounds {[Ni(DNI)2(H2O)3][Ni(DNI)2 (H2O)4]}·6H2O and Pb(DNI)2(H2O)4 (DNI = 2,4-Dinitroimidazolate)

PubMed Central

Zhang, Guo-Fang; Cai, Mei-Yu; Jing, Ping; He, Chong; Li, Ping; Zhao, Feng-Qi; Li, Ji-Zhen; Fan, Xue-Zhong; Ng, Seik Weng

2010-01-01

Two transition-metal compounds derived from 2,4-dinitroimidazole, {[Ni(DNI)2(H2O)3][Ni(DNI)2 (H2O)4]}·6H2O, 1, and Pb(DNI)2(H2O)4, 2, were characterized by elemental analysis, FT-IR, TG-DSC and X-ray single-crystal diffraction analysis. Crystal data for 1: monoclinic, space group C2/c, a = 26.826(3), b = 7.7199(10), c = 18.579(2) Å, β = 111.241(2)° and Z = 4; 2: monoclinic, space group C2/c, a = 6.5347(6), b = 17.1727(17), c = 14.1011(14) Å, β = 97.7248(10) and Z = 4. Compound 1 contains two isolated nickel centers in its structure, one being six-coordinate and another five-coordinate. The structure of 2 contains a lead (II) center surrounded by two chelating DNI ligands and four water molecules in distorted square-antiprism geometry. The abundant hydrogen bonds in two compounds link the molecules into three-dimensional network and stabilize the molecules. The TG-DSC analysis reveals that the first step is the loss of water molecules and the final residue is the corresponding metal oxides and carbon. PMID:20526419

Mercury-Bridged Cobaltacarborane Complexes Containing B-Hg-B Three-Center Bonds. Synthesis and Structure of mu, mu’-((n5-C5R5)Co(CH3)2C2B3H4)Hg, mu-(n(5)-C5R5)Co(CH3)2C2B3H4)HgCl, (R=H, CH3) and Related Compounds.

DTIC Science & Technology

1980-11-01

MERCURY-BRIDGED COBALTACARBORANE COMPLEXES CONTAINING B-HG-B TH--ETC(U) NOV 80 D C FINSTER . R N GRIMES N0 0 0 1 4-75-0305 UNCLASSXFIED TR󈧨 NL ILn...C5R5) Co 3)2C2B3 4 2 5 .- -C5R5 )Co(CH3)2C2B3H4 ]HgCl, (R=H, CH3 ) and Related Compounds, David C./ Finster -- Russell N./Grimes ( Department of Chemistry...Compounds 1 \\David C. Finster And Russell N. Grimes* Abstract. Reactions of the nid~p-cobaltacarborane anions 01CR )(C 3 )C BH and [n (H 1oC ihH~5n 5

X-ray study of the hetero ring flexibility in 5,6-tri-, 5,6-tetra- and 5,6-penta-methylene-2,3,5,6-tetrahydro-1,3-oxazin-4-ones. The structures of 2-spiropentamethylene- cis-5,6-tetramethylene-2,3,5,6-tetrahydro-1,3-oxazin-4-one (I), 2-spiropentamethylene- cis-5,6-pentamethylene-2,3,5,6-tetrahydro-1,3-oxazin-4-one ( c-II) and 2-spiropentamethylene- trans-5,6-pentamethylene-2,3,5,6-tetrahydro-1,3-oxazin-4-one ( t-II)

NASA Astrophysics Data System (ADS)

Ribár, B.; Kapor, Á.; Kálmán, A.; Argay, Gy.; Fülöp, F.; Bernáth, G.

1989-01-01

The structures of the title compounds were established by X-ray crystallography by means of direct methods. Crystals of compound I (C 12H 19NO 2) are monoclinic, space group P2 1/ n, with a = 11.365(3), b = 10.343(4), c = 10.343(2) Å, β = 110.25(3)°, Z = 4 and Dc = 1.218 g cm -3. Crystals of compound c- II (C 13H 21NO 2) are monoclinic, space group C2/ c, with a = 20.830(8), b = 6.594(4), c = 17.944(8) Å, β = 95.83(2)°, Z = 8 and Dc = 1.209 g cm -3. Crystals of t- II (C 13H 21NO 2) are also monoclinic, space group P2 1/ n, with a = 14.268(4), b = 6.112(3), c = 14.041(7) Å, β = 93.63(3)°, Z = 4 and Dc = 1.210 g cm -3. The structures were refined to R = 0.059 for 1697 reflections of I, R = 0.052 for 1718 reflections of c- II, and R = 0.057 for 2178 reflections of t- II. The conformations of the 1,3-oxazin-4-one moieties in the title compounds were compared with those found earlier in related compounds. As shown by an analysis of the puckering parameters (D. Cremer and J.A. Pople, J. Am. Chem. Soc., 97 (1975) 1354), they cluster in a random distribution around the 1H 6 half-chair form. Marked deviation from this canonical form towards the 1E envelope was observed only under the influence of the cyclopentane ring.

Revised Space Groups for Three Molybdenum(V) Phosphate Compounds

NASA Astrophysics Data System (ADS)

Leclaire, A.; Borel, M. M.; Guesdon, A.; Marsh, Richard E.

2001-06-01

The space groups of three previously described Mo(V) phosphate structures are revised. (1) δ-KMo2P3O13, originally reported as triclinic, Poverline1, is revised to monoclinic, C2/c; it is identical to the compound previously identified as K4Mo8P12O52. (2) The compound formulated as [Mo12CdP8O50(OH)12]Cd [N(CH3)4]2(H3O)6·5H2O, originally described as monoclinic, Pn, is revised to P21/n (also monoclinic). (3) Rb3O2(MoO)4(PO4)4, originally reported as orthorhombic, C2221, is revised to tetragonal, P43212. The general descriptions of the structures are unchanged; however, for compound 2 the revision involves the addition of a center of symmetry and, as a result, there are significant changes in the interatomic distances and angles.

Synthesis and Pharmacological Evaluation of Some New Pyrimidine Derivatives Containing 1,2,4-Triazole

PubMed Central

Khanage, Shantaram Gajanan; Raju, S. Appala; Mohite, Popat Baban; Pandhare, Ramdas Bhanudas

2012-01-01

Purpose: An efficient method has been described for synthesis of 6-(substituted aryl)-4-(3,5-diphenyl-1H-1,2,4-triazol-1-yl)-1, 6-dihydropyrimidine-2-thiol, as a beneficial antimicrobial, anticonvulsant and anticancer agents. Methods: The clalcones of title compounds were synthesized in three steps and subsequently these chalcones were further reacted with thiourea in the presence of KOH in ethanol, which led to the formation of dihydropyrimidine derivatives (4a-j). Compounds 4a-j were screened for their in vitro antimicrobial activity by agar well method and their anticonvulsant activity by the MES model. Anticancer activity of two newly synthesized heterocycles were evaluated at National Cancer Institute (NCI) Maryland, USA against 60 cell lines of different human tumor at a single dose of 10-5 M. Results: Compound 4b, 4c, 4d, 4i and 4j were exhibited significant antimicrobial potential against tested strains at 50μg/ml and 100μg/ml concentrations. Out of the ten compounds studied 4a, 4b, 4c, 4h and 4j showed comparable MES activity to Phenytoin and Carbamazepine after 0.5h. Tested compounds did not showed to be more potent than standard drugs after 4h. Compound 4a and 4d were found active on Non-Small Cell Lung Cancer (HOP-92). Conclusion: Ten noveldihydropyrimidine analogues has been synthesized, characterized and found to bepromising antibacterial, anticonvulsant and antitumor agents. PMID:24312796

Structure elucidation of 3-[1-(6-methoxy-2-naphtyl)ethyl]-6-(2,4-dichlorophenyl)-7H-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazine, C 23H 18Cl 2N 4OS from synchrotron X-ray powder diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gündoğdu, Gülsüm; Aytaç, Sevim Peri; Müller, Melanie

The 3-[1-(6-methoxy-2-naphtyl)ethyl]-6-(2,4-dichlorophenyl)-7H-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazine, C 23H 18Cl 2N 4OS compound was synthesized, as a member of the family of novel potential anticancer agents. The structure of the title compound was characterized by IR, 1H-NMR, mass spectroscopy, and elemental analysis, previously. In this study, the crystal structure of this compound has been determined from synchrotron X-ray powder diffraction data. The crystal structure was solved by simulated annealing and the final structure was achieved by Rietveld refinement method using soft restrains on all interatomic bond lengths and angles. This compound crystallizes in space groupP21,Z= 2, with the unit-cell parametersa= 15.55645(11) Å,b= 8.61693(6) Å,c= 8.56702(6)more » Å,β= 104.3270(4)°, andV= 1112.68(1) Å 3. In the crystal structure, strong C-H∙∙∙πand weak intermolecular hydrogen-bonding interactions link the molecules into a three-dimensional network. The molecules are in a head-to-head arrangement in the unit cell.« less

Synthesis and radical scavenging activity of 6-hydroxyl-4-methylcoumarin and its derivatives

NASA Astrophysics Data System (ADS)

Jumal, Juliana; Ayomide, Adetunji Fridaos

2018-06-01

Four compounds of coumarin derivatives namely 6-hydroxyl-4-methylcoumarin (I), 6-hydroxyl-4-methyl-5-(p-nitrophenyl azocoumarin) (II), 6-hydroxyl-4-methyl-5,7-(bis-p-nitrophenyl azocoumarin) (III) and 6-hydroxyl-4-methyl-5,7-(bis-p-chlorophenyl azocoumarin) (IV) were successfully synthesized. These compounds were prepared by reacting hydroquinone with ethylacetoacetate and selected anilines which are chloro and nitro aniline. All synthesized compounds were characterized by CHN micro-elemental analysis, 1H Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR) spectroscopic methods. The infrared spectra of these compounds exhibited five important stretching vibrations: ʋ(-OH), ʋ(C=O), ʋ(C=C), ʋ(C-O) and ʋ(C-N) at 3441-3359 cm-1, 1604-1632 cm-1, 1581-1496 cm-1, 1331-1225 cm-1, 1251-1109 cm-1, respectively. 1H NMR spectra of these compounds show the presence of proton aromatic, proton methyl and proton pyrone ring with the chemical shift at δH 7.00-8.70 ppm, δH 2.20-2.50 ppm and δH 6.10-6.90 ppm, respectively. CHN analysis results of all compounds are in good agreement with the calculated values. All the synthesized compounds were evaluated for their antioxidant activity using DPPH method and ascorbic acid used as the standard. UV-Vis spectroscopic technique was used to investigate the absorbance of these compounds. Compound (II) shows high antioxidant activities compared to compound (I), (III) and (IV) which show moderate to low activities.

Crystal structure, thermochromic and magnetic properties of organic-inorganic hybrid compound: (C7H7N2S)2CuCl4

NASA Astrophysics Data System (ADS)

Vishwakarma, Ashok K.; Kumari, Reema; Ghalsasi, Prasanna S.; Arulsamy, Navamoney

2017-08-01

The synthesis, thermal analysis, crystal structure and magnetic properties of (2-aminobenzothiazolium)2CuCl4, organic-inorganic hybrid compound, have been described. The compound crystallizes in the monoclinic space group P21/c with two formula units in a unit cell of dimensions a = 6.9522(4) Å, b = 9.6979(4) Å, c = 13.9633(6) Å, β = 97.849(3)° and volume 930.83(8) Å3 at 150(2) K. The structure consists of isolated nearly square planer [CuC14]2- units, with somewhat longer than normal Cusbnd Cl bond lengths [Cusbnd Cl (average) = 2.2711 Å]. The magnetic measurements of (2-aminobenzothiazolium)2CuCl4 using SQUID magnetometer show paramagnetic nature of the compound. Thermal measurements (TG-DTA and DSC) on this compound showed reversible phase transition at 83 °C. This transition is accompanied by the reversible change in colour of the prismatic crystal from green to dark brown, thermochromic behaviour. Temperature dependent EPR measurements on powdered sample ascertain change in coordination sphere around Cu(II) with shift in g|| = 2.150 and g⊥ = 2.071 at room temperature, typical of square planar, to g|| = 2.201 and g⊥ = 2.182 at 170 °C, typical of distorted tetrahedral geometry.

A novel synthesis of octahydropyrido[3,2-c]carbazole framework of aspidospermidine alkaloids and a combined computational, FT-IR, NMR, NBO, NLO, FMO, MEP study of the cis-4a-Ethyl-1-(2hydroxyethyl)-2,3,4,4a,5,6,7,11c-octahydro-1H-pyrido[3,2-c]carbazole

NASA Astrophysics Data System (ADS)

Uludağ, Nesimi; Serdaroğlu, Goncagul; Yinanc, Abdullah

2018-06-01

In this study, we performed a novel synthesis of the octahydropyrido[3,2-c]carbazole derivative 6 from 1 in five steps with a 34% overall yield. We also developed a unique compound 2 by a cyclization reaction from the cyanoethylation of compound 1, which is an intermediate step in the synthesis of Aspidospermidine. The parent compound of Aspidospermidine alkaloids, comprise a large family of diverse structures. As a result, we obtained octahydropyrido[3,2-c]carbazole (6)and the proposed method may be applicable to other alkaloids. All quantum chemical calculations of the cis-4a-Ethyl-1-(2-hydroxyethyl)-2,3,4,4a,5,6,7,11c-octahydro-1H-pyrido[3,2-c]carbazole have been performed with the DFT/B3LYP and HF methods by using the Gaussian 09W software package. The most stable conformer obtained from the Potential Energy Surface (PES) scan analysis at the B3LYP/6-31G** level of theory in the gas phase was used as the starting structure of the title compound to further computational analysis. The Natural Bond Orbital (NBO) and NLO analyses were performed to evaluate the intra-molecular interactions contributing to the molecular stability and to predict the optical properties of the title compound, respectively. Gauge-Independent Atomic Orbital (GIAO) approach was used to determine the 1H and 1C NMR chemical shifts of the title compound by subtracting the shielding constants of TMS at both methods. The calculated vibrational frequencies of the title compound were assigned by using the VEDA program and were scaled down by using the scaling factor 0.9668 for B3LYP/6-311++G(d, p) and 0.9050 for HF/6-311++G(d, p) to improve the calculated vibrational frequencies. The FMO (frontier molecular orbital) analysis was evaluated to predict the chemical and physical properties of the title compound and the HOMO, LUMO, and MEP diagrams were visualized by GaussView 4.1 program to present the reactive site of the title compound.

Synthesis, crystal structure and antioxidant evaluation of C-4-acetamidophenylcalix[4]pyrogallolarene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abosadiya, Hamza M.; Hasbullah, Siti Aishah; Yamin, Bohari M.

2015-09-25

C-4-acetamidophenylcalix[4]pyrogallolarene was synthesized by an acid catalyzed condensation reaction of pyrogallol with 4-acetamidobenzaldehyde. The compound was characterized by IR, {sup 1}H and {sup 13}C NMR spectroscopy. Single crystal X-ray analysis revealed that the molecule crystallized in a triclinic system with space group Pī and the unit cell dimensions a= 12.2948(16) Å, b= 13.4423(17) Å, c= 13.5906(18) Å, α =107.549(4)°, β =102.034(4)°, γ =90.535(4)°, Z= 1 and V= 2088.2(5) Å{sup 3}. The macrocyclic calix adopts a chair (C{sub 2h}) conformation and the molecule is associated with eight DMSO molecules of crystallization. Antioxidant test by DPPH method showed that the compound exhibitsmore » good antioxidant activity of about 72%.« less

C-H and H-H Activation in Transition Metal Complexes and on Surfaces.

DTIC Science & Technology

1983-01-01

IEEIIIIIEEEEI EEEIIEIIIIIII EEIIIEIIIEIII IIIEEEIIEIIII La.𔃻 m41. 12.2 1.4o 12.0 1.25 111.4 11. MICROCOP RE SOO TESTCHAR NATIONA BUREA OfSANAD 16m ~4 OFFICE...ML4 plane, bringing a C-H bond in proximity to the metal. The compounds will minimize M. . C-H re- -27 - pulsion by bringing the H atom into an axial...h) C-H activation has been shown also with organolanthanides and organo- actinide compounds : Watson, P.L. J.Chem.Soc. Chem.Commun. 1983, 176-177

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Y.; Zheng, W.T., E-mail: WTZheng@jlu.edu.cn; Guan, W.M.

The structural formation, elastic properties, hardness and electronic structure of TMB{sub 4} (TM=Cr, Re, Ru and Os) compounds are investigated using first-principles approach. The value of C{sub 22} for these compounds is almost two times bigger than the C{sub 11} and C{sub 33}. The intrinsic hardness, shear modulus and Young's modulus are calculated to be in a sequence of CrB{sub 4}>ReB{sub 4}>RuB{sub 4}>OsB{sub 4}, and the Poisson's ratio and B/G ratio of TMB{sub 4} follow the order of CrB{sub 4}ReB{sub 4}>RuB{sub 4}>OsB{sub 4}. • The trend of hardness for TMB{sub 4} is consistent with the variation of elastic modulus. •more » The C{sub 22} value of TMB{sub 4} is bigger than that of C{sub 11} and C{sub 33}. • The high hardness of TMB{sub 4} is originated from the B–B bonds cage.« less

Efficient Electrochemical Synthesis, Antimicrobial and Antiinflammatory Activity of 2–amino-5-substituted- 1,3,4-oxadiazole Derivatives

PubMed Central

Kumar, S.; Srivastava, D. P.

2010-01-01

An efficient electrochemical method for the preparation of 2-amino-5-substituted-1,3,4-oxadiazoles (4a-k) at platinum anode through the electrooxidation of semicarbazone (3a-k) at controlled potential electrolysis has been reported in the present study. The electrolysis was carried out in the acetic acid solvent and lithium perchlorate was used as supporting electrolyte. The products were characterized by IR,1H-NMR,13C-NMR, mass spectra and elemental analysis. The synthesized compounds were screened for their in vitro growth inhibiting activity against different strains of bacteria viz., Klebsilla penumoniae, Escherichia coli, Bassilus subtilis and Streptococcus aureus and antifungal activity against Aspergillus niger and Crysosporium pannical and results have been compared with the standard antibacterial streptomycin and antifungal griseofulvin. Compounds exhibits significant antibacterial activity and antifungal activity. Compounds 4a and g exhibited equal while 4c, d, i and j slightly less antibacterial activity than standard streptomycin. Compounds 4a and g exhibited equal while 4b, c, d, f and i displayed slightly less antifungal activity than standard griseofulvins. PMID:21218056

Synthesis and bioactivities of halogen bearing phenolic chalcones and their corresponding bis Mannich bases.

PubMed

Yamali, Cem; Gul, Halise Inci; Sakagami, Hiroshi; Supuran, Claudiu T

2016-01-01

Phenolic bis Mannich bases having the chemical structure of 1-[3,5-bis-aminomethyl-4-hydroxyphenyl]-3-(4-halogenophenyl)-2-propen-1-ones (1a-c, 2a-c, 3a-c) were synthesized (Numbers 1, 2, and 3 represent fluorine, chlorine, and bromine bearing compounds, respectively, while a, b, and c letters represent the compounds having piperidine, morpholine, and N-methyl piperazine) and their cytotoxic and carbonic anhydrase (CA, EC 4.2.1.1) enzyme inhibitory effects were evaluated. Lead compounds should possess both marked cytotoxic potencies and selective toxicity for tumors. To reflect this potency, PSE values of the compounds were calculated. According to PSE values, the compounds 2b and 3b may serve as lead molecules for further anticancer drug candidate developments. Although the compounds showed a low inhibition potency toward hCA I (25-43%) and hCA II (6-25%) isoforms at 10 μM concentration of inhibitor, the compounds were more selective (1.5-5.2 times) toward hCA I isoenzyme. It seems that the compounds need molecular modifications for the development of better CA inhibitors.

Two novel FeII-oxalate architectures: Solvent-free synthesis, structures, thermal and magnetic studies

NASA Astrophysics Data System (ADS)

Li, Jin-Hua; Liu, Hui; Wei, Li; Wang, Guo-Ming

2015-10-01

Two novel FeII-oxalate framework with the formulas of [NH4][FeIILi3(C2O4)3] (1) and [NH4]2[FeII(C2O4)2]·H2O (2) have been prepared by an oxalic acid flux approach and structurally characterized by IR, elemental analysis, thermogravimetric analysis, single-crystal and powder X-ray diffraction. Heterometallic compound 1 displays a three-dimensional (3D) framework with a pto topology, while homometallic compound 2 features a pillar-layer architecture with a hms topology. Thermal analysis indicates that the two compounds can be stable up to 300 °C and 200 °C, respectively. Magnetic investigations suggest that the FeII ions in 1 and 2 exhibit weak magnetic exchange interactions.

Degradation and environmental risk of surfactants after the application of compost sludge to the soil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gonzalez, M.M.; Martin, J.; Camacho-Munoz, D.

2012-07-15

Highlights: Black-Right-Pointing-Pointer Degradation of surfactants in soil amended with sewage sludge during 100 days. Black-Right-Pointing-Pointer Temperature influences on the degradation of the studied compounds. Black-Right-Pointing-Pointer Overall, the LAS degradation is faster than the NP compounds degradation. Black-Right-Pointing-Pointer Therefore, the LAS presented lower environmental risk than the NP compounds. - Abstract: In this work, the degradation of anionic and non-ionic surfactants in agricultural soil amended with sewage sludge is reported. The compounds analysed were: linear alkylbenzene sulphonates (LAS) with a 10-13 carbon alkylic chain, and nonylphenolic compounds (NPE), including nonylphenol (NP) and nonylphenol ethoxylates with one and two ethoxy groups (NP1EOmore » and NP2EO). The degradation studies were carried out under winter (12.7 Degree-Sign C) and summer (22.4 Degree-Sign C) conditions in Andalusia region. The concentration of LAS was reduced to 2% of the initial concentration 100 day after sludge-application to the soil. The half-life time measured for LAS homologues were ranged between 4 and 14 days at 12.7 Degree-Sign C and between 4 and 7 days at 22.4 Degree-Sign C. With regard to NPE compounds, after 8 and 4 days from the beginning of the experiment at 12.7 and 22.4 Degree-Sign C, respectively, their concentration levels were increased to 6.5 and 13.5 mg/kg dm (dry matter) as consequence of the degradation of nonylphenol polyethoxylates. These concentration levels were reduced to 5% after 63 and 70 days for 12.7 Degree-Sign C and 22.4 Degree-Sign C, respectively. The half-life times measured for NPEs were from 8 to 16 days at 12.7 Degree-Sign C and from 8 to 18 days at 22.4 Degree-Sign C. Environmental risk assessment revealed that for LAS homologues no environment risk could be expected after 7 and 8 days of sludge application to the soil for 22.4 and 12.7 Degree-Sign C, respectively; however, potential toxic effects could be observed for the nonylphenolic compounds during the first 56 days after sludge application to the soil.« less

Synthesis, crystal structure determination and antiproliferative activity of novel 2-amino-4-aryl-4,10-dihydro[1,3,5]triazino[1,2- a]benzimidazoles

NASA Astrophysics Data System (ADS)

Hranjec, Marijana; Pavlović, Gordana; Karminski-Zamola, Grace

2012-01-01

This manuscript describes the synthesis of novel 2-amino-4-aryl-4,10-dihydro-[1,3,5]triazino[1,2- a]benzimidazoles as hydrochloride salts 4a-n and 5b which were prepared in the reaction of cyclocondensation between 2-guanidinobenzimidazole and versatile heteroaromatic aldehydes. Structures of all prepared compounds have been studied by using 1H and 13C NMR, IR and UV/Vis spectroscopy. The crystal and molecular structure of 4f was determined by X-ray diffraction on single crystals. The molecule of 2-amino-4-(4'-methylphenyl)-4,10-dihydro[1,3,5]triazino[1,2- a]benzimidazole hydrochloride 4f (C 16H 16N 5+·Cl -) exists in the solid state in one of the possible tautomeric forms, being protonated at the one of the nitrogen atoms of the 1,4-dihydrotriazine ring. The molecule is highly delocalized within the 4,10-dihydro[1,3,5]triazino[1,2- a]benzimidazole moiety with the highest deviation from the plane for the methine carbon atom and the protonated nitrogen atom of the 1,4-dihydrotriazine ring. The cations are joined via N-H⋯N hydrogen bonds into R22(8) centrosymmetric dimers. Cation dimers are further connected with Cl - ions via N-H⋯Cl and C-H⋯Cl hydrogen bonds into 2D chains spreading along the b axis. The obtained single-crystal X-ray structure determination unequivocally confirms tautomeric form of the compound present in the solid-state and can represent tantative pattern for other prepared compounds. All prepared compounds were tested on their antiproliferative activity in vitro on several human cancer cell lines. Compound 4m was the most active one (IC 50 ≈ 20 μM), while compounds 4d, 4f, 4k, 4l4m showed moderate, but non-selective, antiproliferative activity with IC 50 25-60 μM.

New metal-organic frameworks of [M(C6H5O7)(C6H6O7)(C6H7O7)(H2O)] . H2O (M=La, Ce) and [Ce2(C2O4)(C6H6O7)2] . 4H2O

NASA Astrophysics Data System (ADS)

Weng, Sheng-Feng; Wang, Yun-Hsin; Lee, Chi-Shen

2012-04-01

Two novel materials, [M(C6H5O7)(C6H6O7)(C6H7O7)(H2O)] . H2O (M=La(1a), Ce(1b)) and [Ce2(C2O4)(C6H6O7)2] . 4H2O (2), with a metal-organic framework (MOF) were prepared with hydrothermal reactions and characterized with photoluminescence, magnetic susceptibility, thermogravimetric analysis and X-ray powder diffraction in situ. The crystal structures were determined by single-crystal X-ray diffraction. Compound 1 crystallized in triclinic space group P1¯ (No. 2); compound 2 crystallized in monoclinic space group P21/c (No. 14). The structure of 1 is built from a 1D MOF, composed of deprotonated citric ligands of three kinds. Compound 2 contains a 2D MOF structure consisting of citrate and oxalate ligands; the oxalate ligand arose from the decomposition in situ of citric acid in the presence of CuII ions. Photoluminescence spectra of compounds 1b and 2 revealed transitions between the 5d1 excited state and two levels of the 4f1 ground state (2F5/2 and 2F7/2). Compounds 1b and 2 containing CeIII ion exhibit a paramagnetic property with weak antiferromagnetic interactions between the two adjacent magnetic centers.

Boronic Acid Transition State Inhibitors Active against KPC and Other Class A β-Lactamases: Structure-Activity Relationships as a Guide to Inhibitor Design

PubMed Central

Rojas, Laura J.; Taracila, Magdalena A.; Papp-Wallace, Krisztina M.; Bethel, Christopher R.; Caselli, Emilia; Romagnoli, Chiara; Winkler, Marisa L.; Spellberg, Brad; Prati, Fabio

2016-01-01

Boronic acid transition state inhibitors (BATSIs) are competitive, reversible β-lactamase inhibitors (BLIs). In this study, a series of BATSIs with selectively modified regions (R1, R2, and amide group) were strategically designed and tested against representative class A β-lactamases of Klebsiella pneumoniae, KPC-2 and SHV-1. Firstly, the R1 group of compounds 1a to 1c and 2a to 2e mimicked the side chain of cephalothin, whereas for compounds 3a to 3c, 4a, and 4b, the thiophene ring was replaced by a phenyl, typical of benzylpenicillin. Secondly, variations in the R2 groups which included substituted aryl side chains (compounds 1a, 1b, 1c, 3a, 3b, and 3c) and triazole groups (compounds 2a to 2e) were chosen to mimic the thiazolidine and dihydrothiazine ring of penicillins and cephalosporins, respectively. Thirdly, the amide backbone of the BATSI, which corresponds to the amide at C-6 or C-7 of β-lactams, was also changed to the following bioisosteric groups: urea (compound 3b), thiourea (compound 3c), and sulfonamide (compounds 4a and 4b). Among the compounds that inhibited KPC-2 and SHV-1 β-lactamases, nine possessed 50% inhibitory concentrations (IC50s) of ≤600 nM. The most active compounds contained the thiopheneacetyl group at R1 and for the chiral BATSIs, a carboxy- or hydroxy-substituted aryl group at R2. The most active sulfonamido derivative, compound 4b, lacked an R2 group. Compound 2b (S02030) was the most active, with acylation rates (k2/K) of 1.2 ± 0.2 × 104 M−1 s−1 for KPC-2 and 4.7 ± 0.6 × 103 M−1 s−1 for SHV-1, and demonstrated antimicrobial activity against Escherichia coli DH10B carrying blaSHV variants and blaKPC-2 or blaKPC-3 and against clinical strains of Klebsiella pneumoniae and E. coli producing different class A β-lactamase genes. At most, MICs decreased from 16 to 0.5 mg/liter. PMID:26729496

One-pot microwave assisted synthesis under green chemistry conditions, antioxidant screening, and cytotoxicity assessments of benzimidazole Schiff bases and pyrimido[1,2-a]benzimidazol-3(4H)-ones.

PubMed

Neochoritis, Constantinos G; Zarganes-Tzitzikas, Tryfon; Tsoleridis, Constantinos A; Stephanidou-Stephanatou, Julia; Kontogiorgis, Christos A; Hadjipavlou-Litina, Dimitra J; Choli-Papadopoulou, Theodora

2011-01-01

The synthesis of a number of benzimidazole Schiff bases 3 and 3-oxo-pyrimido[1,2-a]benzimidazoles 4 in excellent yields by a one-step sequence from the reaction of 2-aminobenzimidazole under green chemistry conditions is described. Structural assignments of the new compounds as well as complete assignment of (1)H and (13)C NMR signals have been unambiguously achieved based on the analysis of their (1)H and (13)C NMR (1D and 2D), IR, MS and elemental analysis data. To the synthesized Schiff bases the E-configuration was assigned on the basis of comparison of experimental and calculated (DFT) (13)C NMR chemical shifts. Compounds 3 and 4 were evaluated as inhibitors of lipoxygenase (LOX) and of lipid peroxidation (LPO). All the tested derivatives showed inhibition of lipid peroxidation, whereas most of them were found to have higher activation than the reference compound trolox; The Schiff bases 3e, 3h, and 3i, and the pyrimidobenzimidazoles 4a, 4e and 4f were found to be the most potent. The most potent LOX inhibitor within the subset of Schiff bases was found compound 3i, followed by 3f, whereas compounds 4a and 4g were found the most potent of the 3-oxo-pyrimido[1,2-a]benzimidazole group. Moreover, some cytotoxicity assessments were undertaken, whereupon it was found that Schiff base 3i and pyrimidobenzimidazoles 4e and 4f did not exhibit cytotoxicity at similar concentrations resembling thus the inhibitory activity of lipid peroxidation. The most cytotoxic Schiff base and pyrimidobenzimidazole were found to be 3d and 4c, respectively. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Synthesis of novel fluorinated chalcones derived from 4‧-morpholinoacetophenone and their antiproliferative effects

NASA Astrophysics Data System (ADS)

Kurşun Aktar, Bedriye Seda; Oruç-Emre, Emine Elçin; Demirtaş, Ibrahim; Yaglioglu, Ayse Sahin; Guler, Caglar; Adem, Sevki; Karaküçük Iyidoğan, Ayşegül

2017-12-01

The fluorinated chalcones were synthesized by Claisen-Schmidt condensation between 4‧-morpholineacetophenone and various fluorinated benzaldehydes in the presence of NaOH in methanol. The synthesized compounds [1-7] were evaluated their antiproliferative activity against HeLa and C6 cell lines. Among them, compounds 4 and 5 were determined to have anticancer activity against HeLa cells line (IC50 values of 7.74 and 6.10 μg/mL, respectively). The anticancer activity results were shown that compounds 3, and 6 had inhibitory against C6 cells (IC50 values of 12.80 and 4.16 μg/mL, respectively). The compounds 1 and 2 had high antiproliferative activity with non-cytotoxicity. All of the new compounds, except for compound 4 showed inhibition against the human isozyme hCA I with IC50 in the range of 0.5-1,16 mM. Pyruvate kinase M2 (PKM2) was effectively inhibited by compound 4 with IC50 = 26 μM.

Syntheses, spectroscopic characterization, crystal structure and natural rubber vulcanization activity of new disulfides derived from sulfonyldithiocarbimates

NASA Astrophysics Data System (ADS)

Alves, Leandro de Carvalho; Rubinger, Mayura Marques Magalhães; Tavares, Eder do Couto; Janczak, Jan; Pacheco, Elen Beatriz Acordi Vasques; Visconte, Leila Lea Yuan; Oliveira, Marcelo Ribeiro Leite

2013-09-01

The compounds (Bu4N)2[(4-RC6H4SO2NCS2)2] [Bu4N = tetrabutylammonium cation; R = H (1), F (2), Cl (3) and Br (4)] and (Ph4P)2[(4-RC6H4SO2NCS2)2]ṡH2O [Ph4P = tetraphenylphosphonium cation and R = I (5)] were synthesized by the reaction of the potassium dithiocarbimates (4-RC6H4SO2NCS2K2ṡ2H2O) with I2 and Bu4NBr or Ph4PCl. The IR data were consistent with the formation of the dithiocarbimatodisulfides anions. The NMR spectra showed the expected signals for the cations and anions in a 2:1 proportion. The structures of compounds 1-5 were determined by the single crystal X-ray diffraction. The compounds 2, 3 and 4 are isostructural and crystallise in the centrosymmetric space group C2/c of the monoclinic system. Compound 1 crystallises in the monoclinic system in the space group of P21/n and the compound 5 crystallises in the centrosymmetric space group P-1 of the triclinic system. The complex anions of compounds 2, 3 and 4 exhibit similar conformations having twofold symmetry, while in 1 and 5 the anions exhibit C1 symmetry. The activity of the new compounds in the vulcanization of the natural rubber was evaluated and compared to the commercial accelerators ZDMC, TBBS and TMTD. These studies confirm that the sulfonyldithiocarbimato disulfides anions are new vulcanization accelerators, being slower than the commercial accelerators, but producing a greater degree of crosslinking, and scorch time values compatible with good processing safety for industrial applications. The mechanical properties, stress and tear resistances were determined and compared to those obtained with the commercial accelerators.

Construction of New Coordination Polymers from 4’-(2,4-disulfophenyl)- 3,2’:6’3”-terpyridine: Polymorphism, pH-dependent syntheses, structures, and properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Li; Li, Chao-Jie; He, Jia-En

Nine new coordination compounds, namely, [Co(HDSPTP){sub 2}(H{sub 2}O){sub 4}]·4H{sub 2}O (H{sub 2}DSPTP=4’-(2,4-disulfophenyl)-3,2’:6’3”-terpyridine, 1 and 2), {[Ni(DSPTP)(H_2O)_4]·3H_2O}{sub n} (3), {[Cu(HDSPTP)_2(H_2O)_3]·8H_2O}{sub n} (4), {[Cu(HDSPTP)_2(H_2O)_3]·6H_2O}{sub n} (5), {[Cu(DSPTP)(H_2O)_2]·H_2O}{sub n} (6), {[Zn(DSPTP)(H_2O)_2]·2H_2O}{sub n} (7), {[Cd(DSPTP)(H_2O)_2]·2H_2O}{sub n} (8), and [Ag{sub 2}(DSPTP)(H{sub 2}O)]{sub n} (9), were constructed based on a new ligand containing both terpyridyl and sulfo groups. The reactions of H{sub 2}DSPTP with Co(NO{sub 3}){sub 2}.6H{sub 2}O resulted in two mononuclear complexes (compounds 1 and 2). They are polymorphisms that display different hydrogen bonding networks. They are selectively synthesized by altering the added alkalis. The reaction of H{sub 2}DSPTP with Ni(NO{sub 3}){sub 2}·6H{sub 2}O resultedmore » in a 1D “S-shaped” coordination chain (compound 3). The reactions of Cu(II) with H{sub 2}DSPTP at different pH value resulted in the following three compounds: two kinds of 1D chains obtained at pH 3.0 and 4.0 for compounds 4 and 5, respectively, and a 3D framework based on binuclear ring units with 4-connected sra topology (Compound 6). The reactions of H{sub 2}DSPTP with ds-block ions resulted in the following three compounds: a Zn(II) (compound 7) and a Cd(II) (compound 8) 3D frameworks with structures similar to that in compound 6, and a 3D framework based on tetranuclear Ag(I) SBUs with binodal (4,8)-connected flu type 3D framework topology. The structural diversity is mainly attributed to the rich coordination modes (from monodentate to µ{sub 7}-mode) and conformations (cis–cis and cis–trans) of HDSPTP{sup −}/DSPTP{sup 2−} ligands and the metal center and can be controllable synthesized by altering the alkalis, and pH value. Thermal stability of all compounds was performed, and the thermal behaviors of compounds 6 and 8 were further explored by PXRD. Compound 6 exhibits low thermal stability and undergo a crystalline–crystalline-amorphous phase transition as temperature increases from 25 °C to 200 °C, and show amorphous–crystalline phase transition when rehydrated. However, compound 8 exhibits high thermal stability above 500 °C. Its crystalline phase can retain above 300 °C and undergo a crystalline–crystalline phase transition as temperature increased to 400 °C, and transit back to compound 8 when rehydrated. Moreover, luminescence properties of compounds 7–9 were also investigated. - Graphical abstract: Series of coordination compounds based on a new terpyridine-based ligand, 4’-(2,4-disulfophenyl)-3,2’:6’3’’-terpyridine, were constructed. The syntheses, structural diversity, thermal stability, phase transition, and luminescent properties of selected compounds were explored. - Highlights: • Nine coordination polymers based on a new terpyridine-based ligand were obtained. • Both metal ion and coordination modes of H2DSPTP affect the structural diversity. • The Co(II) compounds are polymorphisms. • The pH-dependent syntheses of Cu(II) compounds were observed. • Compounds 6 and 8 exhibit phase transmission as temperature increased.« less

Synthesis of sulfadiazinyl acyl/aryl thiourea derivatives as calf intestinal alkaline phosphatase inhibitors, pharmacokinetic properties, lead optimization, Lineweaver-Burk plot evaluation and binding analysis.

PubMed

Sajid-Ur-Rehman; Saeed, Aamer; Saddique, Gufran; Ali Channar, Pervaiz; Ali Larik, Fayaz; Abbas, Qamar; Hassan, Mubashir; Raza, Hussain; Fattah, Tanzeela Abdul; Seo, Sung-Yum

2018-06-02

To seek the new medicinal potential of sulfadiazine drug, the free amino group of sulfadiazine was exploited to obtain acyl/aryl thioureas using simple and straightforward protocol. Acyl/aryl thioureas are well recognized bioactive pharmacophore containing moieties. A new series (4a-4j) of sulfadiazine derived acyl/aryl thioureas was synthesized and characterized through spectroscopic and elemental analysis. The synthesized derivatives 4a-4j were subjected to calf intestinal alkaline phosphatase (CIAP) activity. The derivative 4a-4j showed better inhibition potential compared to standard monopotassium phosphate (MKP). The compound 4c exhibited higher potential in the series with IC 50 0.251 ± 0.012 µM (standard KH 2 PO 4 4.317 ± 0.201 µM). Lineweaver-Burk plots revealed that most potent derivative 4c inhibition CIAP via mixed type pathway. Pharmacological investigations showed that synthesized compounds 4a-4j obey Lipinsk's rule. ADMET parameters evaluation predicted that these molecule show significant lead like properties with minimum possible toxicity and can serve as templates in drug designing. The synthetic compounds show none mutagenic and irritant behavior. Molecular docking analysis showed that compound 4c interacts with Asp273, His317 and Arg166 amino acid residues. Copyright © 2018. Published by Elsevier Ltd.

Deviation between the chemistry of Ce(IV) and Pu(IV) and routes to ordered and disordered heterobimetallic 4f/5f and 5f/5f phosphonates.

PubMed

Diwu, Juan; Wang, Shuao; Good, Justin J; DiStefano, Victoria H; Albrecht-Schmitt, Thomas E

2011-06-06

The heterobimetallic actinide compound UO(2)Ce(H(2)O)[C(6)H(4)(PO(3)H)(2)](2)·H(2)O was prepared via the hydrothermal reaction of U(VI) and Ce(IV) in the presence of 1,2-phenylenediphosphonic acid. We demonstrate that this is a kinetic product that is not stable with respect to decomposition to the monometallic compounds. Similar reactions have been explored with U(VI) and Ce(III), resulting in the oxidation of Ce(III) to Ce(IV) and the formation of the Ce(IV) phosphonate, Ce[C(6)H(4)(PO(3)H)(PO(3)H(2))][C(6)H(4)(PO(3)H)(PO(3))]·2H(2)O, UO(2)Ce(H(2)O)[C(6)H(4)(PO(3)H)(2)](2)·H(2)O, and UO(2)[C(6)H(4)(PO(3)H)(2)](H(2)O)·H(2)O. In comparison, the reaction of U(VI) with Np(VI) only yields Np[C(6)H(4)(PO(3)H)(2)](2)·2H(2)O and aqueous U(VI), whereas the reaction of U(VI) with Pu(VI) yields the disordered U(VI)/Pu(VI) compound, (U(0.9)Pu(0.1))O(2)[C(6)H(4)(PO(3)H)(2)](H(2)O)·H(2)O, and the Pu(IV) phosphonate, Pu[C(6)H(4)(PO(3)H)(PO(3)H(2))][C(6)H(4)(PO(3)H)(PO(3))]·2H(2)O. The reactions of Ce(IV) with Np(VI) yield disordered heterobimetallic phosphonates with both M[C(6)H(4)(PO(3)H)(PO(3)H(2))][C(6)H(4)(PO(3)H)(PO(3))]·2H(2)O (M = Ce, Np) and M[C(6)H(4)(PO(3)H)(2)](2)·2H(2)O (M = Ce, Np) structures, as well as the Ce(IV) phosphonate Ce[C(6)H(4)(PO(3)H)(PO(3)H(2))][C(6)H(4)(PO(3)H)(PO(3))]·2H(2)O. Ce(IV) reacts with Pu(IV) to yield the Pu(VI) compound, PuO(2)[C(6)H(4)(PO(3)H)(2)](H(2)O)·3H(2)O, and a disordered heterobimetallic Pu(IV)/Ce(IV) compound with the M[C(6)H(4)(PO(3)H)(PO(3)H(2))][C(6)H(4)(PO(3)H)(PO(3))]·2H(2)O (M = Ce, Pu) structure. Mixtures of Np(VI) and Pu(VI) yield disordered heterobimetallic Np(IV)/Pu(IV) phosphonates with both the An[C(6)H(4)(PO(3)H)(PO(3)H(2))][C(6)H(4)(PO(3)H)(PO(3))]·2H(2)O (M = Np, Pu) and An[C(6)H(4)(PO(3)H)(2)](2)·2H(2)O (M = Np, Pu) formulas. © 2011 American Chemical Society

Design, synthesis and bioevaluation of novel umbelliferone analogues as potential mushroom tyrosinase inhibitors.

PubMed

Ashraf, Zaman; Rafiq, Muhammad; Seo, Sung-Yum; Babar, Mustafeez Mujtaba; Zaidi, Najam-Us-Sahar Sadaf

2015-12-01

A series of umbelliferone analogues were synthesized and their inhibitory effects on the DPPH and mushroom tyrosinase were evaluated. The results showed that some of the synthesized compounds exhibited significant mushroom tyrosinase inhibitory activities. Especially, 2-oxo-2-[(2-oxo-2H-chromen-7-yl)oxy]ethyl-2,4-dihydroxybenzoate (4e) bearing 2,4-dihydroxy substituted phenyl ring exhibited the most potent tyrosinase inhibitory activity with IC50 value 8.96 µM and IC50 value of kojic acid is 16.69. The inhibition mechanism analyzed by Lineweaver-Burk plots revealed that the type of inhibition of compound 4e on tyrosinase was non-competitive. The docking study against tyrosinase enzyme was also performed to determine the binding affinity of the compounds. The compounds 4c and 4e showed the highest binding affinity with active binding site of tyrosinase. The initial structure activity relationships (SARs) analysis suggested that further development of such compounds might be of interest. The statistics of our results endorses that compounds 4c and 4e may serve as a structural template for the design and development of novel tyrosinase inhibitors.

Phosphorus-nitrogen compounds: Part 28. Syntheses, structural characterizations, antimicrobial and cytotoxic activities, and DNA interactions of new phosphazenes bearing vanillinato and pendant ferrocenyl groups

NASA Astrophysics Data System (ADS)

Tümer, Yasemin; Asmafiliz, Nuran; Kılıç, Zeynel; Hökelek, Tuncer; Yasemin Koç, L.; Açık, Leyla; Yola, Mehmet Lütfi; Solak, Ali Osman; Öner, Yağmur; Dündar, Devrim; Yavuz, Makbule

2013-10-01

The gradually Cl replacement reactions of spirocyclic mono (1 and 2) and bisferrocenyl cyclotriphosphazenes (3-5) with the potassium salt of 4-hydroxy-3-methoxybenzaldehyde (potassium vanillinate) gave mono (1a-5a), geminal (gem-1b-5b), non-geminal (cis-1b, cis-5b and trans-2b-5b), tri (1c-5c) and tetra-substituted phosphazenes (1d-5d). Some phosphazenes have stereogenic P-center(s). The chirality of 4c was verified using chiral HPLC column. Electrochemical behaviors were influenced only by the number of ferrocene groups, but not the length of the amine chains and the substituent(s). The structures of the new phosphazenes were determined by FTIR, MS, 1H, 13C and 31P NMR, HSQC and HMBC spectral data. The solid-state structures of cis-1b and 4d were examined by single crystal X-ray diffraction techniques. The twelve phosphazene derivatives were screened for antimicrobial activity and the compounds 5a, cis-1b and 2c exhibited the highest antibacterial activity against G(+) and G(-) bacteria. In addition, it was found that overall gem-1b inhibited the growth of Mycobacterium tuberculosis. The compounds 1d, 2d and 4d were tested in HeLa cancer cell lines. Among these compounds, 2d had cytotoxic effect on HeLa cell in the first 48 h. Moreover, interactions between compounds 2a, gem-1b, gem-2b, cis-1b, 2c, 3c, 4c, 5c, 1d, 2d and 4d, and pBR322 plasmid DNA were investigated.

Weakly-bridged dimeric diorganotin(IV) compounds derived from pyruvic acid hydrazone Schiff base ligands: Synthesis, characterization and crystal structures

NASA Astrophysics Data System (ADS)

Hong, Min; Yin, Han-Dong; Cui, Ji-Chun

2011-03-01

We report the synthesis of four diorganotin(IV) compounds of Schiff base pyruvic acid hydrazone derivatives formulated as [R 2SnLY] 2, where L 1 is 2-SC 4H 3CON 2C(CH 3)CO 2 with Y = CH 3CH 2CH 2CH 2OH, R = n-Bu ( 1); L 2 is C 6H 5CON 2C(CH 3)CO 2 with Y = CH 3CH 2OH, R = p-F-Bz ( 2); L 3 is 2-HOC 6H 4CON 2C(CH 3)CO 2 with Y dbnd H 2O, R = p-CN -Bz ( 3); and L 4 is 4-NO 2-C 6H 4CON 2C(CH 3)CO 2 with Y dbnd CH 3CH 2OH, R = Bz ( 4). The structures of all compounds have been established by a combination of single-crystal X-ray diffraction analysis, 1H and 119Sn NMR spectroscopy, IR spectroscopy, and elemental analysis. Studies reveal that four ligands present the same coordination mode with tin center, which all present tridentate ONO donor Schiff bases and coordinate to the tin center in an enolic form. In compounds 1- 4, each tin atom is seven-coordinated and exhibits a distorted pentagonal bipyramid with a planar SnO 4N unit and two apical alkyl carbon atoms, thus forming a weakly-bridged dimeric molecule. Additionally, the distance of Sn⋯O bridge in each compound is obviously affected by the choice of different alkyl groups and coordination solvent molecules, which fluctuates in the range of 2.571(5)-2.839(4) Å. Furthermore, the supramolecular structure analysis show that there are two types of supramolecular infrastructures, 1D chain or 2D network, which are formed by intermolecular O-H···N or C-H⋯X (X = O, N or F) hydrogen bonds.

Carvacrol derivatives as mushroom tyrosinase inhibitors; synthesis, kinetics mechanism and molecular docking studies.

PubMed

Ashraf, Zaman; Rafiq, Muhammad; Nadeem, Humaira; Hassan, Mubashir; Afzal, Samina; Waseem, Muhammad; Afzal, Khurram; Latip, Jalifah

2017-01-01

The present work describesthe development of highly potent mushroom tyrosinase inhibitor better than the standard kojic acid. Carvacrol derivatives 4a-f and 6a-d having substituted benzoic acid and cinnamic acidresidues were synthesized with the aim to possess potent tyrosinase inhibitory activity.The structures of the synthesized compounds were ascertained by their spectroscopic data (FTIR, 1HNMR, 13CNMR and Mass Spectroscopy).Mushroom tyrosinase inhibitory activity of synthesized compounds was determined and it was found that one of the derivative 6c possess higher activity (IC50 0.0167μM) than standard kojic acid (IC50 16.69μM). The derivatives 4c and 6b also showed good tyrosinase inhibitory activity with (IC50 16.69μM) and (IC50 16.69μM) respectively.Lineweaver-Burk and Dixon plots were used for the determination of kinetic mechanism of the compounds 4c and 6b and 6c. The kinetic analysis revealed that compounds 4c and 6b showed mixed-type inhibition while 6c is a non-competitive inhibitor having Ki values19 μM, 10 μM, and 0.05 μMrespectively. The enzyme inhibitory kinetics further showed thatcompounds 6b and 6c formed irreversible enzyme inhibitor complex while 4c bind reversibly with mushroom tyrosinase.The docking studies showed that compound 6c have maximum binding affinity against mushroom tyrosinase (PDBID: 2Y9X) with binding energy value (-7.90 kcal/mol) as compared to others.The 2-hydroxy group in compound 6c interacts with amino acid HIS85 which is present in active binding site. The wet lab results are in good agreement with the dry lab findings.Based upon our investigation we may propose that the compound 6c is promising candidate for the development of safe cosmetic agent.

Crystal structure, quantum mechanical investigation, IR and NMR spectroscopy of two new organic salts: (C8H12NO)·[NO3] (I) and (C8H14N4)·[ClO4]2 (II)

NASA Astrophysics Data System (ADS)

Bayar, I.; Khedhiri, L.; Soudani, S.; Lefebvre, F.; Pereira da Silva, P. S.; Ben Nasr, C.

2018-06-01

Two new organic-inorganic hybrid materials, 4-methoxybenzylammonium nitrate, (C8H12NO)·[NO3] (I), and 2-(1-piperazinyl)pyrimidinium bis(perchlorate), (C8H14N4)·[ClO4]2(II), have been synthesized by an acid/base reaction at room temperature, their structures were determined by single crystal X-ray diffraction. Compound (I) crystallizes in the orthorhombic system and Pnma space group with a = 15.7908 (7), b = 6.8032 (3), c = 8.7091 (4) Å, V = 935.60 (7) Å3 with Z = 4. Full-matrix least-squares refinement converged at R = 0.038 and wR(F2) = 0.115. Compound (II) belongs to the monoclinic system, space group P21/c with the following parameters: a = 10.798(2), b = 7.330(1), c = 21.186(2) Å, β = 120.641 (4)°, V = 1442.7 (3) Å3and Z = 4. The structure was refined to R = 0.044, wR(F2) = 0.132. In the structures of (I) and (II), the anionic and cationic entities are interconnected by hydrogen bonding contacts forming three-dimensional networks. Intermolecular interactions were investigated by Hirshfeld surfaces and the contacts of the four different chloride atoms in (II) were compared. The Molecular Electrostatic Potential (MEP) maps and the HOMO and LUMO energy gaps of both compounds were computed. The vibrational absorption bands were identified by infrared spectroscopy. These compounds were also investigated by solid-state 13C, 35Cl and 15N NMR spectroscopy. DFT calculations allowed the attribution of the IR and NMR bands.

Compound-specific stable carbon isotopic signature of carbohydrate pyrolysis products from C3 and C4 plants.

PubMed

González-Pérez, José A; Jiménez-Morillo, Nicasio T; de la Rosa, José M; Almendros, Gonzalo; González-Vila, Francisco J

2016-02-01

Pyrolysis-compound specific isotopic analysis (Py-CSIA: Py-GC-(FID)-C-IRMS) is a relatively novel technique that allows on-line quantification of stable isotope proportions in chromatographically separated products released by pyrolysis. Validation of the Py-CSIA technique is compulsory for molecular traceability in basic and applied research. In this work, commercial sucrose from C4 (sugarcane) and C3 (sugarbeet) photosystem plants and admixtures were studied using analytical pyrolysis (Py-GC/MS), bulk δ(13)C IRMS and δ(13)C Py-CSIA. Major pyrolysis compounds were furfural (F), furfural-5-hydroxymethyl (HMF) and levoglucosan (LV). Bulk and main pyrolysis compound δ(13)C (‰) values were dependent on plant origin: C3 (F, -24.65 ± 0.89; HMF, -22.07 ± 0.41‰; LV, -21.74 ± 0.17‰) and C4 (F, -14.35 ± 0.89‰; HMF, -11.22 ± 0.54‰; LV, -11.44 ± 1.26‰). Significant regressions were obtained for δ(13)C of bulk and pyrolysis compounds in C3 and C4 admixtures. Furfural (F) was found (13)C depleted with respect to bulk and HMF and LV, indicating the incorporation of the light carbon atom in position 6 of carbohydrates in the furan ring after pyrolysis. This is the first detailed report on the δ(13)C signature of major pyrolytically generated carbohydrate-derived molecules. The information provided by Py-CSIA is valuable for identifying source marker compounds of use in food science/fraud detection or in environmental research. © 2015 Society of Chemical Industry.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Songchen; Manna, Kuntal; Ellern, Arkady

In order to facilitate oxidative addition chemistry of fac-coordinated rhodium(I) and iridium(I) compounds, carbene–bis(oxazolinyl)phenylborate proligands have been synthesized and reacted with organometallic precursors. Two proligands, PhB(OxMe2)2(ImtBuH) (H[1]; OxMe2 = 4,4-dimethyl-2-oxazoline; ImtBuH = 1-tert-butylimidazole) and PhB(OxMe2)2(ImMesH) (H[2]; ImMesH = 1-mesitylimidazole), are deprotonated with potassium benzyl to generate K[1] and K[2], and these potassium compounds serve as reagents for the synthesis of a series of rhodium and iridium complexes. Cyclooctadiene and dicarbonyl compounds {PhB(OxMe2)2ImtBu}Rh(η4-C8H12) (3), {PhB(OxMe2)2ImMes}Rh(η4-C8H12) (4), {PhB(OxMe2)2ImMes}Rh(CO)2 (5), {PhB(OxMe2)2ImMes}Ir(η4-C8H12) (6), and {PhB(OxMe2)2ImMes}Ir(CO)2 (7) are synthesized along with ToMM(η4-C8H12) (M = Rh (8); M = Ir (9); ToM = tris(4,4-dimethyl-2-oxazolinyl)phenylborate). The spectroscopicmore » and structural properties and reactivity of this series of compounds show electronic and steric effects of substituents on the imidazole (tert-butyl vs mesityl), effects of replacing an oxazoline in ToM with a carbene donor, and the influence of the donor ligand (CO vs C8H12). The reactions of K[2] and [M(μ-Cl)(η2-C8H14)2]2 (M = Rh, Ir) provide {κ4-PhB(OxMe2)2ImMes'CH2}Rh(μ-H)(μ-Cl)Rh(η2-C8H14)2 (10) and {PhB(OxMe2)2ImMes}IrH(η3-C8H13) (11). In the former compound, a spontaneous oxidative addition of a mesityl ortho-methyl to give a mixed-valent dirhodium species is observed, while the iridium compound forms a monometallic allyl hydride. Photochemical reactions of dicarbonyl compounds 5 and 7 result in C–H bond oxidative addition providing the compounds {κ4-PhB(OxMe2)2ImMes'CH2}RhH(CO) (12) and {PhB(OxMe2)2ImMes}IrH(Ph)CO (13). In 12, oxidative addition results in cyclometalation of the mesityl ortho-methyl similar to 10, whereas the iridium compound reacts with the benzene solvent to give a rare crystallographically characterized cis-[Ir](H)(Ph) complex. Alternatively, the rhodium carbonyl 5 or iridium isocyanide {PhB(OxMe2)2ImMes}Ir(CO)CNtBu (15) reacts with PhSiH3 in the dark to form the silyl compound {PhB(OxMe2)2ImMes}RhH(SiH2Ph)CO (14) or {PhB(OxMe2)2ImMes}IrH(SiH2Ph)CNtBu (17). These examples demonstrate the enhanced thermal reactivity of {PhB(OxMe2)2ImMes}-supported iridium and rhodium carbonyl compounds in comparison to tris(oxazolinyl)borate, tris(pyrazolyl)borate, and cyclopentadienyl-supported compounds.« less

Symmetry breaking in the planar configurations of disilicon tetrahalides: Pseudo-Jahn-Teller effect parameters, hardness and electronegativity.

PubMed

Kouchakzadeh, Ghazaleh; Nori-Shargh, Davood

2015-11-21

CCSD(T), MP2, LC-BLYP, LC-ωPBE and B3LYP methods with the Def2-TZVPP basis set and natural bond orbital (NBO) interpretations were performed to investigate the correlations between the Pseudo-Jahn-Teller Effect (PJTE) parameters [i.e. vibronic coupling constant values (F), energy gaps between reference states (Δ) and the primary force constant (K0)], structural and configurational properties, global hardness, global electronegativity, natural bond orders, stabilization energies associated with electron delocalizations and natural atomic charges of disilicon tetrafluoride (1), disilicon tetrachloride (2), disilicon tetrabromide (3) and disilicon tetraiodide (4). All levels of theory showed the trans-bent (C2h) configurations as the energy minimum structures of compounds 1-4, and the flap angles between the X2Si planes and the Si=Si bonds in the distorted (C2h) configurations decrease from compound 1 to compound 4. The negative curvatures of the ground state electronic configurations and the positive curvatures of the excited states of the adiabatic potential energy surfaces (APESs) which resulted from the mixing of the ground Ag and excited B2g states are due to the PJTE (i.e. PJT(Ag + B2g) ⊗ b2g problem). Contrary to the usual expectation, with the decrease of the energy gaps between reference states (Δ), the PJTE stabilization energy, E(PJT), decreases from compound 1 to compound 4. The canonical molecular orbital (CMO) analysis revealed that the contributions of the ψ(HOMO)(b3u) and ψL(UMO)(b1u) molecular orbitals in the vibronic coupling constant (F) decrease from compound 1 to compound 4. This fact clearly justifies the decrease of the vibronic coupling constant (F) and the primary force constant (the force constant without the PJTE) values on going from compound 1 to compound 4, leading to the decrease of the negative curvatures of the ground state electronic configuration curves of their corresponding APESs. The results obtained showed that the stabilization energies associated with the mixing of the distorted donor π(Si-Si)(b(u)) bonding and acceptor σ(Si-Si)*(b(u)) antibonding orbitals along the b2g bending distortions decrease from compound 1 to compound 4. This fact reasonably explains the increase of the Si-Si natural bond orders (nbo) on going from compound 1 to compound 4. With the increase of the Si-Si natural bond orders, the corresponding E(PJT) decreases from compound 1 to compound 4. Importantly, the variations of the global hardness (η) differences (Δ[η(C2h) - η(D2h)]) do not correlate with the trend observed for their corresponding total energy differences, justifying that the configurational properties of compounds 1-4 do not obey the maximum hardness principle. Interestingly, the trans-bent (C2h) configurations of compounds 1-4 are more electronegative than their corresponding planar (D2h) forms and the variations of their global electronegativity (χ) differences (Δ[χ(C2h) - χ(D2h)]) succeed in accounting for the decrease of the E(PJT) stabilization energies for the D2h → C2h conversion processes on going from compound 1 to compound 4.

Products of hexachlorocyclopentadiene (C-56) in aqueous solution

USGS Publications Warehouse

Chou, S.-F.J.; Griffin, R.A.; Chou, I.-Ming; Larson, R.A.

1987-01-01

The photodegradation and degradation products of hexachlorocyclopentadiene (C-56) in aqueous solutions were studied in the laboratory. In each case, the half-life of C-56 was less than 4 min when exposed to sunlight. At least eight degradation products were positively or tentatively identified: 2,3,4,4,5-Pentachloro-2-cyclopentenone, hexachloro-2-cyclopentenone and hexachloro-3-cyclopentenone were the primary photodegradation products, and pentachlorocis-2,4-pentadienoic acid, Z- and E-pentachlorobutadiene and tetrachlorobutyne were the secondary degradation products. Dissociation of the primary photolysis products may proceed through corresponding pentadienoic acids to form smaller molecular weight compounds such as pentachlorobutadiene isomers and tetrachlorobutyne. In addition, dimerization of 2,3,4,4,5-pentachloro-2-cyclopentenone to form higher molecular weight compounds such as hexachloroindenone may present a minor route of degradation. The results also indicate that C-56 is highly photoreactive and suggest a possible pathway for the compound's transformation in the environment when exposed to sunlight. ?? 1987.

Synthesis and crystal structures of inclusion compounds of 2,2'-dithiosalicylic acid and triethylamine/tripropylamine

NASA Astrophysics Data System (ADS)

Yang, Y. X.; Li, H. Y.; Wu, J. F.

2015-12-01

Herein we reported two new inclusion compounds of 2,2'-dithiosalicylic acid (C14H10O4S2, DTSA) and triethylamine and tripropylamine, [C14H8O4S 2 2- · [N+(C2H5)3]2 · H2O] (1) and [C14H10O4S2 · C14H8O4S 2 2- · [N+(C3H7)3]2] (2). Compound 1: triclinic P overline 1, a = 8.2159(2), b = 12.5724(3), c = 14.9203(3) Å, α = 97.0390(10), β = 101.4310(10)°, γ = 101.3370(10)°, V = 1460.06(6) Å3, Z = 2, R 1 = 0.0526, wR 2 = 0.1495; Compound 2: monoclinic P21/ c, a = 20.5178(13), b = 15.3623(8), c = 15.5529(9) Å, β = 102.036(3)°, V = 4794.5(5) Å3, Z = 4, R 1 = 0.0533, wR 2 = 0.1252. In these two crystal structures, DTSA utilizes conventional O-H···O hydrogen bonds to link to generate varied host lattices, in which the central N atoms of the guest amine molecules accept the protons of DTSA to form the corresponding cations to act as the couterions to develop the stable crystal structures. Noticeably, except Van der Waals forces usually existing between the host and guest molecules, the central N atoms of the guests of the two compounds can construct strong N-H…O hydrogen bonds with the related host molecules, which further enforce the host-guest interactions to help form the final inclusion compounds.

Phytotoxicity, structural and computational analysis of 2-methyl-1,5-diarylpentadienones

NASA Astrophysics Data System (ADS)

Din, Zia Ud; Rodrigues-Filho, Edson; de Cassia Pereira, Viviane; Gualtieri, Sonia Cristina Juliano; Deflon, Victor Marcelo; da Silva Maia, Pedro Ivo; Kuznetsov, Aleksey E.

2017-08-01

In our studies aimed to produce new chemicals used in weed control, 2-methyl-1,5-diarylpentadienones were synthesized by the reaction of p-methoxybenzaldehyde, p-nitrobenzaldehyde and p-N,N-dimethylbenzaldehyde, respectively, with 2-butanone, resulting in four model compounds. The phytotoxicity of these compounds against wheat coleoptiles and Sesame seedling was observed at μM concentrations, indicating good potential for their usage in weed management in the field. Spectroscopic and computational studies were performed in order to gain understanding on their mechanisms of action and to clarify some structural complexities due existence of conformers and substituent effects. These compounds probably act as hydroxyphenylpyruvate dioxygenase inhibitors. The tested compounds were characterized by spectroscopic and single crystal X-ray diffraction analyses. Solid crystalline state of the compound A (2-Methyl-1-(p-methophyphenyl)-5-(phenyl)-diarylpentadienone) is observed in the monoclinic space group P21/c with unit cell dimensions a = 14.3366(4) Å, b = 11.3788(4) Å, c = 9.6319(3) Å, β = 96.596, V = 1560.88(9) Å3 and Z = 4. Compound C (2-Methyl-1-(p-methophyphenyl)-5-(p-nitrophenyl)-diarylpentadienone) crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 17.8276(9) Å, b = 7.3627(4) Å, c = 12.9740(6) Å, β = 107.6230(10), V = 1623.04(14) Å3 and Z = 4. LC-UV-MS analysis furnished important data helpful for their characterization. The spectroscopic data and computational (DFT) analysis revealed the fact that each of the compounds A-D occurs in solution as four conformers.

Formation and ecotoxicity of N-heterocyclic compounds on ammoxidation of mono- and polysaccharides.

PubMed

Klinger, Karl Michael; Liebner, Falk; Fritz, Ines; Potthast, Antje; Rosenau, Thomas

2013-09-25

Ammoxidation of technical lignins under mild conditions is a suitable approach to artificial humic substances. However, carbohydrates as common minor constituents of technical lignins have been demonstrated to be a potential source of N-heterocyclic ecotoxic compounds. Ethyl acetate extracts of ammoxidation mixtures of the monosaccharides glucose and xylose exhibited considerable growth inhibiting activity in the OECD 201 test, with 4-methyl-1H-imidazole, 4-(hydroxymethyl)-1H-imidazole, and 3-hydroxypyridine being the most active compounds. The amount of N-heterocyclic compounds formed at moderate ammoxidation conditions (70 °C, 0.2 MPa O2, 3 h) was significantly lower for the polysaccharides cellulose and xylan (16-30 μg/g of educt) compared to glucose (15.4 mg). Ammoxidation at higher temperature is not recommendable for carbohydrate-rich materials as much higher amounts of N-heterocyclic compounds were formed from both monosaccharides (100 °C: 122.4-160.5 mg/g of educt) and polysaccharides (140 °C: 5.52-16.03 mg/g of educt).

A Novel Spirooxindole Derivative Inhibits the Growth of Leishmania donovani Parasites both In Vitro and In Vivo by Targeting Type IB Topoisomerase

PubMed Central

Saha, Sourav; Acharya, Chiranjit; Pal, Uttam; Chowdhury, Somenath Roy; Sarkar, Kahini; Maiti, Nakul C.

2016-01-01

Visceral leishmaniasis is a fatal parasitic disease, and there is an emergent need for development of effective drugs against this neglected tropical disease. We report here the development of a novel spirooxindole derivative, N-benzyl-2,2′α-3,3′,5′,6′,7′,7α,α′-octahydro-2methoxycarbonyl-spiro[indole-3,3′-pyrrolizidine]-2-one (compound 4c), which inhibits Leishmania donovani topoisomerase IB (LdTopIB) and kills the wild type as well as drug-resistant parasite strains. This compound inhibits catalytic activity of LdTopIB in a competitive manner. Unlike camptothecin (CPT), the compound does not stabilize the DNA-topoisomerase IB cleavage complex; rather, it hinders drug-DNA-enzyme covalent complex formation. Fluorescence studies show that the stoichiometry of this compound binding to LdTopIB is 2:1 (mole/mole), with a dissociation constant of 6.65 μM. Molecular docking with LdTopIB using the stereoisomers of compound 4c produced two probable hits for the binding site, one in the small subunit and the other in the hinge region of the large subunit of LdTopIB. This spirooxindole is highly cytotoxic to promastigotes of L. donovani and also induces apoptosis-like cell death in the parasite. Treatment with compound 4c causes depolarization of mitochondrial membrane potential, formation of reactive oxygen species inside parasites, and ultimately fragmentation of nuclear DNA. Compound 4c also effectively clears amastigote forms of wild-type and drug-resistant parasites from infected mouse peritoneal macrophages but has less of an effect on host macrophages. Moreover, compound 4c showed strong antileishmanial efficacies in the BALB/c mouse model of leishmaniasis. This compound potentially can be used as a lead for developing excellent antileishmanial agents against emerging drug-resistant strains of the parasite. PMID:27503653

N-2-Hydroxy-4-methoxyacetophenone- N'-4-nitrobenzoyl hydrazine: Synthesis and structural characterization

NASA Astrophysics Data System (ADS)

Bessy Raj, B. N.; Kurup, M. R. Prathapachandra

2007-04-01

A new aroyl hydrazone, N-2-hydroxy-4-methoxyacetophenone- N'-4-nitrobenzoyl hydrazine was prepared by the condensation reaction of 2-hydroxy-4-methoxyacetophenone and 4-nitrobenzoyl hydrazine. Characterization of the compound was done by elemental analysis and electronic, infrared and NMR spectral analyses. The complete structural assignment of the compound was done by NMR studies by using COSY homonuclear and HSQC heteronuclear techniques. The crystal and molecular structure was determined by single crystal X-ray diffraction studies: crystallized in the monoclinic system, space group P2 1/ n, Z = 4, a = 7.3343(9) Å, b = 20.3517(9) Å, c = 10.1375(5) Å, α = 90.00°, β = 95.735(7)° and γ = 90.00°. From the crystal structure, it is concluded that the compound exists as the keto isomer in the solid state. There is a completely extended conformation in the central part of the molecule C5 sbnd C8 dbnd N1 sbnd N2 sbnd C10 dbnd O2 with an E configuration at the double bond of the hydrazinic bridge.

Synthesis and TFT Properties of Fluorenyl Cored Conjugated Compound for Organic Thin Film Transistors.

PubMed

Kim, You Geun; Shaik, Baji; Jang, Yong Ju; Park, Song Yi; Kim, Jin Young; Lee, Sang-Gyeong

2016-03-01

The 5,5'-(4,4'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(4,1-phenylene))bis(2-hexylthieno[3,2-b]thiophene) FCBT (6) was synthesized by connecting the fluorenyl, thienothiophenyl and phenyl units. The compound was characterized by FT-IR, H1NMR, C13NMR and mass spectroscopy. The compound has shown good solubility and thermal stability over 417 degrees C. The compound has shown hole mobility of 4.76 x 10(-6) cm2Ns. The on-off ratio and threshold voltage were 7.5 x 10(2) and -8.26 V respectively.

Unexpected formation of 1-[4-chloromethylphenyl]-5-[4-(methylsulfonyl)benzyl]-1H-tetrazole and 1-[4-chloromethylphenyl]-5-[4-(aminosulfonyl)phenyl]-1H-tetrazole: Crystal structure, bioassay screening and molecular docking studies

NASA Astrophysics Data System (ADS)

Jawabrah Al-Hourani, Baker; Ali, Basem F.; Judeh, Zaher; El-Barghouthi, Musa I.; Al-Awaida, Wajdy; Snobar, Yasmin; El Soubani, Fatima; Matalka, Khalid; Wuest, Frank

2018-07-01

During the cyclization reaction of benzyl alcohol containing amides, using NaN3 and SiCl4, additional unique chlorination development was observed to yield the novel azoles 1-[4-chloromethylphenyl]-5-[4-(methylsulfonyl)benzyl]-1H-tetrazole (3a) and 1-[4-chloromethylphenyl]-5-[4-(aminosulfonyl)phenyl]-1H-tetrazole (3b). Control experiments showed that the SiCl4 or SiCl3N3 has the major role for such functional group transformation in such a clean reaction and quantitative yield. Their molecular structures have been ascertained using the X-ray crystallography technique in addition to the spectroscopic analyses. Both compounds 3a and 3b crystallize in the monoclinic space group P21/c. The cell parameters of azole 3a are a = 22.3827 (8), Å, b = 5.1602 (2) Å, c = 13.4994 (5) Å3, β = 95.2352 (14)°, V = 1552.67 (10) Å3, and Z = 4. While the cell parameters of azole 3b are a = 20.582 (2), Å, b = 5.8947 (7) Å, c = 13.0796 (16) Å3, β = 104.376 (4)°, V = 1537.2 (3) Å3, and Z = 4. The central tetrazole ring of both compounds is planar and bears (4-chloromethylphenyl) at position one (N-1) of the central moiety. However, the substituents 4-(methylsulfonyl)phenyl and 4-(aminosulfonyl)phenyl of azoles 3a and 3b, respectively, are attached to the C-5 of the same central unit. The phenyl rings at N-1, (C2sbnd C7) and C9sbnd C14 in (3a); (C2sbnd C7) and (C8sbnd C14) in (3b) are inclined compared to the tetrazole ring with dihedral angles of 21.74° and 83.94° in 3a and 25.85° and 65.13° in 3b. The two phenyl rings, at N-1 and C-5, are rotated against each other by 87.73° (in 3a) and 72.21° (in 3b). In the crystal, intermolecular interactions between molecules of 3a,b are dominated by Csbnd H⋯O and Csbnd H⋯N hydrogen bonds. Additional Cl…π interactions add extra supramolecularity. All intermolecular interaction motifs consolidate a three dimensional network lattice. The molecular docking studies were carried out to understand the interaction of compounds 3a and 3b within the active site of the cyclooxygenase-2 enzyme, followed by a comparison study with the celecoxib drug as a reference compound. The in vitro bioassay screenings of azoles 3a and 3b showed that both compounds have poor selectivity and weak inhibition potency toward cyclooxygenase-2 enzyme.

Fluorine bearing sydnones with styryl ketone group: synthesis and their possible analgesic and anti-inflammatory activities.

PubMed

Deshpande, Shreenivas Ramachandrarao; Pai, Karkala Vasantakumar

2012-04-01

In continuation of structure activity relationship studies, a panel of fluorine containing sydnones with styryl ketone group 4-[1-oxo-3-(substituted aryl)-2-propenyl]-3-(3-chloro-4-fluorophenyl)sydnones 2a-i, was synthesized as better analgesic and anti-inflammatory agents. The title compounds were formed by condensing 4-acetyl-3-(3-chloro-4-fluorophenyl)sydnone with various substituted aryl aldehydes, characterized by spectral studies and evaluated at 100 mg\\kg b.w., p.o. for analgesic, anti-inflammatory and ulcerogenic activities. Compounds 2c and 2e showed good analgesic effect in acetic acid-induced writhing while none showed significant activity in hot plate assay in mice. In carrageenan-induced rat paw oedema test, compound 2c and 2f exhibited good anti-inflammatory effect at 3rd h, whereas compounds 2c, 2e, 2d, 2g and 2h showed activity in croton oil induced ear oedema assay in mice. Compounds 2c and 2e were less ulcerogenic than ibuprofen in rats, when tested by ulcer index method. Compounds with electron attracting substituents such as 2c and 2e were found to be promising in terms of the ratio of efficacy and adverse effect. These compounds generally exhibited better activity than those of earlier series signifying fluorine substitution.

Alkali metal complexes of sterically demanding amino-functionalized secondary phosphanide ligands.

PubMed

Izod, Keith; Stewart, John C; Clegg, William; Harrington, Ross W

2007-01-14

The reaction between {(Me(3)Si)(2)CH}PCl(2) (4) and one equivalent of either [C(6)H(4)-2-NMe(2)]Li or [2-C(5)H(4)N]ZnCl, followed by in situ reduction with LiAlH(4) gives the secondary phosphanes {(Me(3)Si)(2)CH}(C(6)H(4)-2-NMe(2))PH (5) and {(Me(3)Si)(2)CH}(2-C(5)H(4)N)PH (6) in good yields as colourless oils. Metalation of 5 with Bu(n)Li in THF gives the lithium phosphanide [[{(Me(3)Si)(2)CH}(C(6)H(4)-2-NMe(2))P]Li(THF)(2)] (7), which undergoes metathesis with either NaOBu(t) or KOBu(t) to give the heavier alkali metal derivatives [[{(Me(3)Si)(2)CH}(C(6)H(4)-2-NMe(2))P]Na(tmeda)] (8) and [[{(Me(3)Si)(2)CH}(C(6)H(4)-2-NMe(2))P]K(pmdeta)] (9) after recrystallization in the presence of the corresponding amine co-ligand [tmeda = N,N,N',N'-tetramethylethylenediamine, pmdeta = N,N,N',N'',N''-pentamethyldiethylenetriamine]. The pyridyl-functionalized phosphane 6 undergoes deprotonation on treatment with Bu(n)Li to give a red oil corresponding to the lithium compound [{(Me(3)Si)(2)CH}(2-C(5)H(4)N)P]Li (10) which could not be crystallized. Treatment of this oil with NaOBu(t) gives the sodium derivative [{[{(Me(3)Si)(2)CH}(2-C(5)H(4)N)P]Na}(2) x (Et(2)O)](2) (11), whilst treatment of with KOBu(t), followed by recrystallization in the presence of pmdeta gives the complex [[{(Me(3)Si)(2)CH}(2-C(5)H(4)N)P]K(pmdeta)](2) (12). Compounds 5-12 have been characterised by (1)H, (13)C{(1)H} and (31)P{(1)H} NMR spectroscopy and elemental analyses; compounds 7-9, and 12 have additionally been characterised by X-ray crystallography. Compounds 7-9 crystallize as discrete monomers, whereas 11 crystallizes as an unusual dimer of dimers and 12 crystallizes as a dimer with bridging pyridyl-phosphanide ligands.

Compound C Inhibits Vascular Smooth Muscle Cell Proliferation and Migration in an AMP-Activated Protein Kinase-Independent Fashion

PubMed Central

Peyton, Kelly J.; Yu, Yajie; Yates, Benjamin; Shebib, Ahmad R.; Liu, Xiao-ming; Wang, Hong

2011-01-01

6-[4-(2-Piperidin-1-yl-ethoxy)-phenyl]-3-pyridin-4-yl-pyrazolo[1,5-a] pyrimidine (compound C) is a cell-permeable pyrrazolopyrimidine derivative that acts as a potent inhibitor of AMP-activated protein kinase (AMPK). Although compound C is often used to determine the role of AMPK in various physiological processes, it also evokes AMPK-independent actions. In the present study, we investigated whether compound C influences vascular smooth muscle cell (SMC) function through the AMPK pathway. Treatment of rat aortic SMCs with compound C (0.02–10 μM) inhibited vascular SMC proliferation and migration in a concentration-dependent fashion. These actions of compound C were not mimicked or affected by silencing AMPKα expression or infecting SMCs with an adenovirus expressing a dominant-negative mutant of AMPK. In contrast, the pharmacological activator of AMPK 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside inhibited the proliferation and migration of SMCs in a manner that was strictly dependent on AMPK activity. Flow cytometry experiments revealed that compound C arrested SMCs in the G0/G1 phase of the cell cycle, and this was associated with a decrease in cyclin D1 and cyclin A protein expression and retinoblastoma protein phosphorylation and an increase in p21 protein expression. Finally, local perivascular delivery of compound C immediately after balloon injury of rat carotid arteries markedly attenuated neointima formation. These studies identify compound C as a novel AMPK-independent regulator of vascular SMC function that exerts inhibitory effects on SMC proliferation and migration and neointima formation after arterial injury. Compound C represents a potentially new therapeutic agent in treating and preventing occlusive vascular disease. PMID:21566210

Compound C inhibits vascular smooth muscle cell proliferation and migration in an AMP-activated protein kinase-independent fashion.

PubMed

Peyton, Kelly J; Yu, Yajie; Yates, Benjamin; Shebib, Ahmad R; Liu, Xiao-ming; Wang, Hong; Durante, William

2011-08-01

6-[4-(2-Piperidin-1-yl-ethoxy)-phenyl]-3-pyridin-4-yl-pyrazolo[1,5-a] pyrimidine (compound C) is a cell-permeable pyrrazolopyrimidine derivative that acts as a potent inhibitor of AMP-activated protein kinase (AMPK). Although compound C is often used to determine the role of AMPK in various physiological processes, it also evokes AMPK-independent actions. In the present study, we investigated whether compound C influences vascular smooth muscle cell (SMC) function through the AMPK pathway. Treatment of rat aortic SMCs with compound C (0.02-10 μM) inhibited vascular SMC proliferation and migration in a concentration-dependent fashion. These actions of compound C were not mimicked or affected by silencing AMPKα expression or infecting SMCs with an adenovirus expressing a dominant-negative mutant of AMPK. In contrast, the pharmacological activator of AMPK 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside inhibited the proliferation and migration of SMCs in a manner that was strictly dependent on AMPK activity. Flow cytometry experiments revealed that compound C arrested SMCs in the G(0)/G(1) phase of the cell cycle, and this was associated with a decrease in cyclin D1 and cyclin A protein expression and retinoblastoma protein phosphorylation and an increase in p21 protein expression. Finally, local perivascular delivery of compound C immediately after balloon injury of rat carotid arteries markedly attenuated neointima formation. These studies identify compound C as a novel AMPK-independent regulator of vascular SMC function that exerts inhibitory effects on SMC proliferation and migration and neointima formation after arterial injury. Compound C represents a potentially new therapeutic agent in treating and preventing occlusive vascular disease.

Bioprospecting marine actinomycetes for multidrug-resistant pathogen control from Rameswaram coastal area, Tamil Nadu, India.

PubMed

Wahaab, Femina; Subramaniam, Kalidass

2018-01-01

A potent Streptomyces bacillaris strain RAM25C4 was isolated for controlling methicillin-resistant Staphylococcus aureus and multidrug-resistant bacteria such as Staphylococcus aureus, Acinetobacter baumannii, and Pseudomonas aeruginosa. A total of 131 actinomycetes were isolated from the Rameswaram coastal region, Tamil Nadu, India. Among 131 actinomycetes, maximum number of actinomycetes (55%) isolated at the distance of 3-6 m from seashore. Out of 131 actinomycetes, 85% of the actinomycetes exhibited different degree of antagonistic activity against test pathogens. The antagonistic activity evaluated using actinomycetes direct culture filtrate and culture filtrate extracts. Among these culture filtrate, extracts had supreme antagonistic activity against multidrug-resistant bacteria and the solvent ethyl acetate was the best for extracting secondary metabolites from actinomycetes. In HPTLC analysis, the presence of macrolides, terpenoids, and quinolones was identified in RAM25C4 extract. In GC-MS analysis, various potent compounds such as phenolic compound-2,6-di-tert-butylphenol, alkaloid compound-1H, 5H, pyrrolo (1' 2':3, 4) imidazo, and quinolone compound-1,4-benzenediol, 2,5-bis(1,1-dimethylethyl) were identified in the ethyl acetate extract of RAM25C4. The phylogenetic analysis of 16S rRNA gene sequence of RAM25C4 isolate was deposited in NCBI with name Streptomyces bacillaris strain RAM25C4 and accession number KM513543.

Amino Compounds as Inhibitors of De Novo Synthesis of Chlorobenzenes

NASA Astrophysics Data System (ADS)

Wang, Si-Jia; He, Pin-Jing; Lu, Wen-Tao; Shao, Li-Ming; Zhang, Hua

2016-04-01

The inhibitory effects of four amino compounds on the formation of chlorobenzenes (CBzs) - dioxin precursors and indicators, and the inhibitory mechanisms were explored. The results show NH4H2PO4 can decrease the total yields of CBzs (1,2di-CBz, 1,3di-CBz, 1,4di-CBz, penta-CBz and hexa-CBz) by 98.1%±1.6% and 96.1%±0.7% under air and nitrogen flow. The inhibitory effects indicated by the total yields of CBzs follow the order NH4H2PO4 > NH4HF2 > (NH4)2SO4 > NH4Br under air flow and NH4H2PO4 ≈ (NH4)2SO4 ≈ NH4HF2 >NH4Br under nitrogen flow. The inhibition mechanism revealed by thermal analysis that CuCl2 was converted to CuPO3 by reacting with NH4H2PO4 below 200 °C, which can block the transfer of chlorine and formation of C-Cl bonds at 350 °C. The effects of the other three inhibitors were weaker because their reactions with CuCl2, which form other copper compounds, and the reaction of CuCl2 with carbon, which forms C-Cl bonds, were almost simultaneous and competitive. Oxygen influenced the yield of CBzs obviously, and the total yield of five CBzs sharply increased with oxygen. Because of their high efficiency, low environmental impact, low cost, and availability, amino compounds - especially NH4H2PO4 - can be utilized as inhibitors of CBzs during incineration.

Alkaline earth metal complexes of a phosphine-borane-stabilized carbanion: synthesis, structures, and stabilities.

PubMed

Izod, Keith; Wills, Corinne; Clegg, William; Harrington, Ross W

2007-05-14

The reaction between either MgI2 or CaI2 and 2 equiv of [(Me3Si)2{Me2(H3B)P}C]K (2) in toluene gives the corresponding organo-alkaline earth metal compounds [(Me3Si)2{Me2(H3B)P}C]2M in moderate to good yields [M = Mg (3), Ca (4)]. Compound 3 crystallizes solvent-free, whereas X-ray quality crystals of 4 could not be obtained in the absence of coordinating solvents; crystallization of 4 from cold methylcyclohexane/THF gives the solvate [(Me3Si)2{Me2(H3B)P}C]2Ca(THF)4 (4a). The corresponding heavier alkaline earth metal complexes [(Me3Si)2{Me2(H3B)P}C]2M(THF)5 [M = Sr (7), Ba (8)] are obtained from the reaction between MI2 and 2 equiv of 2 in THF, followed by recrystallization from cold methylcyclohexane/THF. Compound 3 degrades over a period of several weeks at room-temperature both in the solid state and in toluene solution to give the free phosphine-borane (Me3Si)2{Me2(H3B)P}CH (5) as the sole phosphorus-containing product. In addition, compounds 3, 4, and 4a react rapidly with THF in toluene solution, yielding 5 as the sole phosphorus-containing product; in contrast, compounds 7 and 8 are stable toward this solvent.

The influence of conformational restriction in the C-terminus of growth hormone secretagogues on their potency.

PubMed

Peschke, Bernd; Ankersen, Michael; Bauer, Michael; Hansen, Thomas Kruse; Hansen, Birgit Sehested; Nielsen, Karin Kramer; Raun, Kirsten; Richter, Lutz; Westergaard, Lisbet

2002-06-01

In order to obtain more potent growth hormone secretagogues, a comparison of ipamorelin and NN703 suggested the addition of a polar group at the C-terminus of NN703. A study was conducted using constrained amines for this purpose. Here, substituted 4-piperidinylamino- and 4-dimethylaminopiperidino-substituents were found to give the most active compounds. A replacement of the 4-dimethylaminopiperidino-substituent with 4-hydroxypiperidino resulted in a series of compounds, which showed in vitro activity with EC(50) values in the low nanomolar range, and favourable kinetic properties, such as 40% oral bioavailability. The most promising compound was also tested in a swine in vivo model, resulting in a growth hormone level with a C(max) of over 40 ng mL(-1).

Novel Penicillin Analogues as Potential Antimicrobial Agents; Design, Synthesis and Docking Studies.

PubMed

Ashraf, Zaman; Bais, Abdul; Manir, Md Maniruzzaman; Niazi, Umar

2015-01-01

A number of penicillin derivatives (4a-h) were synthesized by the condensation of 6-amino penicillinic acid (6-APA) with non-steroidal anti-inflammatory drugs as antimicrobial agents. In silico docking study of these analogues was performed against Penicillin Binding Protein (PDBID 1CEF) using AutoDock Tools 1.5.6 in order to investigate the antimicrobial data on structural basis. Penicillin binding proteins function as either transpeptidases or carboxypeptidases and in few cases demonstrate transglycosylase activity in bacteria. The excellent antibacterial potential was depicted by compounds 4c and 4e against Escherichia coli, Staphylococcus epidermidus and Staphylococcus aureus compared to the standard amoxicillin. The most potent penicillin derivative 4e exhibited same activity as standard amoxicillin against S. aureus. In the enzyme inhibitory assay the compound 4e inhibited E. coli MurC with an IC50 value of 12.5 μM. The docking scores of these compounds 4c and 4e also verified their greater antibacterial potential. The results verified the importance of side chain functionalities along with the presence of central penam nucleus. The binding affinities calculated from docking results expressed in the form of binding energies ranges from -7.8 to -9.2kcal/mol. The carboxylic group of penam nucleus in all these compounds is responsible for strong binding with receptor protein with the bond length ranges from 3.4 to 4.4 Ǻ. The results of present work ratify that derivatives 4c and 4e may serve as a structural template for the design and development of potent antimicrobial agents.

Novel Penicillin Analogues as Potential Antimicrobial Agents; Design, Synthesis and Docking Studies

PubMed Central

Ashraf, Zaman; Bais, Abdul; Manir, Md. Maniruzzaman; Niazi, Umar

2015-01-01

A number of penicillin derivatives (4a-h) were synthesized by the condensation of 6-amino penicillinic acid (6-APA) with non-steroidal anti-inflammatory drugs as antimicrobial agents. In silico docking study of these analogues was performed against Penicillin Binding Protein (PDBID 1CEF) using AutoDock Tools 1.5.6 in order to investigate the antimicrobial data on structural basis. Penicillin binding proteins function as either transpeptidases or carboxypeptidases and in few cases demonstrate transglycosylase activity in bacteria. The excellent antibacterial potential was depicted by compounds 4c and 4e against Escherichia coli, Staphylococcus epidermidus and Staphylococcus aureus compared to the standard amoxicillin. The most potent penicillin derivative 4e exhibited same activity as standard amoxicillin against S. aureus. In the enzyme inhibitory assay the compound 4e inhibited E. coli MurC with an IC50 value of 12.5 μM. The docking scores of these compounds 4c and 4e also verified their greater antibacterial potential. The results verified the importance of side chain functionalities along with the presence of central penam nucleus. The binding affinities calculated from docking results expressed in the form of binding energies ranges from -7.8 to -9.2kcal/mol. The carboxylic group of penam nucleus in all these compounds is responsible for strong binding with receptor protein with the bond length ranges from 3.4 to 4.4 Ǻ. The results of present work ratify that derivatives 4c and 4e may serve as a structural template for the design and development of potent antimicrobial agents. PMID:26267242

Synthesis of Bisimidazole Derivatives for Selective Sensing of Fluoride Ion.

PubMed

Zhang, Liang; Liu, Fang

2017-09-11

Rapid and efficient analysis of fluoride ion is crucial to providing key information for fluoride ion hazard assessment and pollution management. In this study, we synthesized one symmetrical structure called 1,4-bis(4,5-diphenyl-1 H -imidazol-2-yl)benzene ( 1a ) and two asymmetrical structures, namely 2-(4-(4,5-diphenyl-1 H -imidazol-2-yl)phenyl)-1 H -phenanthro(9,10- d )imidazole ( 1b ) and 2-(4-(4,5-diphenyl-1 H -imidazol-2-yl)phenyl)-1 H -imidazo(4,5- f )(1,10)phenanthroline ( 1c ), which served as an efficient anion sensor for fluoride ion over a wide range of other anions (Cl - , Br - , I - , NO₃ - , ClO₄ - , HSO₄ - , BF₄ - , and PF₆ - ) owing to imidazole group in the main backbone. The absorption intensity of compound 1a at λ max 358 nm slightly decreased; however, a new band at λ max 414 nm appeared upon the addition of fluoride ion, while no evident change occurred upon the addition of eight other anions. The photoluminescence intensity of compound 1a at λ max 426 nm was nearly quenched and fluorescence emission spectra were broadened when fluoride ion was added into dimethyl sulfoxide (DMSO) solution of compound 1a . Compared with the optical behaviors of the DMSO solution of compound 1a in the presence of Bu₄N⁺F - , compounds 1b and 1c exhibited considerable sensitivity to fluoride ion due to the increase in coplanarity. Furthermore, compared with the fluorescence emission behaviors of the DMSO solutions of compounds 1a and 1b in the presence of Bu₄N⁺F - , compound 1c exhibited the most significant sensitivity to fluoride ion due to the charge transfer enhancement. Consequently, the detection limits of compounds 1a - 1 c increased from 5.47 × 10 -6 M to 4.21 × 10 -6 M to 9.12 × 10 -7 M. Furthermore, the largest red shift (75 nm) of the DMSO solution compound 1c in the presence of fluoride ion can be observed. Our results suggest that the increase in coplanarity and the introduction of electron-withdrawing groups to the imidazole backbone can improve the performance in detecting fluoride ion.

Cyclic 3-alkyl pyridinium alkaloid monomers from a New Zealand Haliclona sp. marine sponge.

PubMed

Damodaran, Vidhiya; Ryan, Jason L; Keyzers, Robert A

2013-10-25

Bioassay and NMR approaches have been used to guide the isolation of one known and two new cyclic 3-alkyl pyridinium alkaloid (3-APA) monomers from the New Zealand marine sponge Haliclona sp. The new compounds, dehydrohaliclocyclins C (3) and F (4), are the first reported examples of cyclic 3-APA monomers with unsaturation in the alkyl chain. The known compound haliclocyclin C (2) was also isolated from a mixture with 4. The structures of compounds 2-4 were elucidated using NMR spectroscopy, mass spectrometry, and chemical degradation.

Antitrypanosomal lead discovery: Identification of a ligand-efficient inhibitor of Trypanosoma cruzi CYP51 and parasite growth

PubMed Central

Andriani, Grasiella; Amata, Emanuele; Beatty, Joel; Clements, Zeke; Coffey, Brian J.; Courtemanche, Gilles; Devine, William; Erath, Jessey; Juda, Cristin E.; Wawrzak, Zdzislaw; Wood, JodiAnne T.; Lepesheva, Galina I.; Rodriguez, Ana; Pollastri, Michael P.

2013-01-01

Chagas disease is caused by the intracellular protozoan parasite Trypanosomal cruzi, and current drugs are lacking in terms of desired safety and efficacy profiles. Following on a recently reported high-throughput screening campaign, we have explored initial structure-activity relationships around a class of imidazole-based compounds. This profiling has uncovered compounds 4c (NEU321) and 4j (NEU704), which are potent against in vitro cultures of T. cruzi and are greater than 160-fold selective over host cells. We report in vitro drug metabolism and properties profiling of 4c and show that this chemotype inhibits the T cruzi CYP51 enzyme, an observation confirmed by X-ray crystallographic analysis. We compare the binding orientation of 4c to that of other, previously reported inhibitors. We show that 4c displays a significantly better ligand efficiency and a shorter synthetic route over previously disclosed CYP51 inhibitors, and should therefore be considered a promising lead compound for further optimization. PMID:23448316

Ferrocenyl-cymantrenyl hetero-bimetallic chalcones: Synthesis, structure and biological properties

NASA Astrophysics Data System (ADS)

Mishra, Sasmita; Tirkey, Vijaylakshmi; Ghosh, Avishek; Dash, Hirak R.; Das, Surajit; Shukla, Madhulata; Saha, Satyen; Mobin, Sheikh M.; Chatterjee, Saurav

2015-04-01

Two new ferrocenyl-cymantrenyl bimetallic chalcones, [(CO)3Mn(η5-C5H4)C(O)CHdbnd CH(η5-C5H4)Fe(η5-C5H5)] (1) and [{(CO)3Mn(η5-C5H4)C(O)CHdbnd CH(η5-C5H4)}2Fe] (2) have been synthesized. Their reactivity study with triphenylphosphine and bis-(diphenylphosphino)ferrocene led to the isolation of phosphine substituted bimetallic chalcones (3-6). Single crystal X-ray structural characterization for 1 and its phosphine analogue (3) reveals their different conformational identity with anti-conformation for 1, while syn-conformation for 3. Investigation of antimalarial and antibacterial activities was carried out for compounds 1 and 2 against two strains of Plasmodium falciparum (3D7, K1) and four bacterial strains. TD-DFT calculation was performed for compound 1 and electrochemical properties were studied for bimetallic chalcone compounds by cyclic voltammetric technique.

Superconductivity in Ternary Rare-Earth Transition Metal Silicides and Germanides with the SCANDIUM(5) COBALT(4) SILICON(10)-TYPE Structure.

NASA Astrophysics Data System (ADS)

Berg, Linda Sue

A systematic study of the superconducting and normal state properties of some ternary rare earth transition metal silicides and germanides of the Sc(,5)Co(,4)Si(,10) -type is reported in this work. Low temperature heat capacity measurements indicate the presence of a complicated phonon density of states in these structurally complex compounds. A better description of the phonon spectrum of the high T(,c) materials, Sc(,5)Rh(,4)Si(,10), Sc(,5)Ir(,4)Si(,10), and Y(,5)Os(,4)Ge(,10), given by a model proposed by Junod et al.('1), is presented and discussed. The large values of (DELTA)C/(gamma)(,n)T(,c) and the electron-phonon coupling constant for these high T(,c) compounds indicate that they are strong-coupled superconductors. Relative to other ternary superconductors, many of these materials have large Debye temperatures. The BSC theory does not seem to afford an adequate description of the supercon- ducting state in these compounds. DC electrical resistivity measurements on these compounds show resistivity behaviors deviating from those exhibited by simple metals. The (rho)(T) data for Y(,5)Ir(,4)Si(,10), Lu(,5)Rh(,4)Si(,10), Lu(,5)Ir(,4)Si(,10), and Y(,5)Os(,4)Ge(,10), indicate the presence of anomalies. Static molar magnetic susceptibility measurements performed on these compounds indicate (1) a small effective magnetic moment of 0.26(mu)(,B) on the Co atom and (2) anomalous behaviors in the Lu(,5)Rh(,4)Si(,10), Lu(,5)Ir(,4)Si(,10), Y(,5)Ir(,4)Si(,10), Lu(,5)Ir(,4)Ge(,10), and Y(,5)Rh(,4)Ge(,10) data. It is suggested that the same mechanism, namely, the forma- tion of a charge- or spin-density wave, is causing the anomalous behaviors in both the resistivity and susceptibility data. Lastly, upper critical magnetic field measurements were performed on Sc(,5)Co(,4)Si(,10), Sc(,5)Rh(,4)Si(,10), Sc(,5)Ir(,4)Si(,10), Lu(,5)Rh(,4)Si(,10), Lu(,5)Ir(,4)Si(,10), and Y(,5)Os(,4)Ge(,10). Relative to the other five samples, Y(,5)Os(,4)Ge(,10) exhibits very high values for (-dH(,c2)/dT)(,Tc) = 10.2 kOe/ K and H(,c2)(0) = 60.4 kOe. Comparing the value of (-dH(,c2)/dT)(,Tc) gained from the fit of the data to the WHH theory to the calculated (-dH(,c2)/dT)(,Tc) yields various degrees of agreement for these com- pounds. Indications are also that (1) there seems to be little or no. Pauli limiting and (2) the spin-orbit effect appears to be negligible in these compounds. *DOE Report IS-T-1215. This work was performed under contract No. W-7405-Eng-82 with the U. S. Department of Energy. ('1)A. Junod, D. Bichsel, and J. Muller, Helv. Phys. Acta 52, 580 (1979).

Rh(III)-Catalyzed C-H Activation of Benzoylacetonitriles and Tandem Cyclization with Diazo Compounds to Substituted Benzo[ de]chromenes.

PubMed

Fang, Feifei; Zhang, Chunmei; Zhou, Chaofan; Li, Yazhou; Zhou, Yu; Liu, Hong

2018-04-06

Rh (III)-catalyzed C-H activation of benzoylacetonitriles in coupling with diazo compounds was developed to synthesize diversified substituted benzo[ de]chromenes via a formal (4 + 2) cycloaddition with a diazo compound and subsequent tandem (4 + 2) cycloaddition with another diazo compound. Intriguingly, synthesis of substituted benzo[ de]chromenes and their decarboxylation products could be realized by controlling the reaction conditions. These reactions have a broad range of substrates, moderate to good yields, and high regioselectivity.

A series of (E)-5-(arylideneamino)-1-tert-butyl-1H-pyrrole-3-carbonitriles and their reduction products to secondary amines: syntheses and X-ray structural studies.

PubMed

Macías, Mario A; Castillo, Juan Carlos; Portilla, Jaime

2018-01-01

An efficent access to a series of N-(pyrrol-2-yl)amines, namely (E)-1-tert-butyl-5-[(4-chlorobenzylidene)amino]-1H-pyrrole-3-carbonitrile, C 16 H 16 ClN 3 , (7a), (E)-1-tert-butyl-5-[(2,4-dichlorobenzylidene)amino]-1H-pyrrole-3-carbonitrile, C 16 H 15 Cl 2 N 3 , (7b), (E)-1-tert-butyl-5-[(pyridin-4-ylmethylene)amino]-1H-pyrrole-3-carbonitrile, C 15 H 16 N 4 , (7c), 1-tert-butyl-5-[(4-chlorobenzyl)amino]-1H-pyrrole-3-carbonitrile, C 16 H 18 ClN 3 , (8a), and 1-tert-butyl-5-[(2,4-dichlorobenzyl)amino]-1H-pyrrole-3-carbonitrile, C 16 H 17 Cl 2 N 3 , (8b), by a two-step synthesis sequence (solvent-free condensation and reduction) starting from 5-amino-1-tert-butyl-1H-pyrrole-3-carbonitrile is described. The syntheses proceed via isolated N-(pyrrol-2-yl)imines, which are also key synthetic intermediates of other valuable compounds. The crystal structures of the reduced compounds showed a reduction in the symmetry compared with the corresponding precursors, viz. Pbcm to P-1 from compound (7a) to (8a) and P2 1 /c to P-1 from compound (7b) to (8b), probably due to a severe change in the molecular conformations, resulting in the loss of planarity observed in the nonreduced compounds. In all of the crystals, the supramolecular assembly is controlled mainly by strong (N,C)-H...N hydrogen bonds. However, in the case of (7a)-(7c), C-H...Cl interactions are strong enough to help in the three-dimensional architecture, as observed in Hirshfeld surface maps.

Gas chromatography-mass spectrometry of carbonyl compounds in cigarette mainstream smoke after derivatization with 2,4-dinitrophenylhydrazine.

PubMed

Dong, Ji-Zhou; Moldoveanu, Serban C

2004-02-20

An improved gas chromatography-mass spectrometry (GC-MS) method was described for the analysis of carbonyl compounds in cigarette mainstream smoke (CMS) after 2,4-dinitrophenylhydrazine (DNPH) derivatization. Besides formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde, methyl ethyl ketone, butyraldehyde, and crotonaldehyde that are routinely analyzed in cigarette smoke, this technique separates and allows the analysis of several C4, C5 and C6 isomeric carbonyl compounds. Differentiation could be made between the linear and branched carbon chain components. In cigarette smoke, the branched chain carbonyls are found at higher level than the linear chain carbonyls. Also, several trace carbonyl compounds such as methoxyacetaldehyde were found for the first time in cigarette smoke. For the analysis, cigarette smoke was collected using DNPH-treated pads, which is a simpler procedure compared to conventional impinger collection. Thermal decomposition of DNPH-carbonyl compounds was minimized by the optimization of the GC conditions. The linear range of the method was significantly improved by using a standard mixture of DNPH-carbonyl compounds instead of individual compounds for calibration. The minimum detectable quantity for the carbonyls ranged from 1.4 to 5.6 microg/cigarette.

Twilight zone sponges from Guam yield theonellin isocyanate and psammaplysins I and J.

PubMed

Wright, Anthony D; Schupp, Peter J; Schrör, Jan-Philipp; Engemann, Anna; Rohde, Sven; Kelman, Dovi; de Voogd, Nicole; Carroll, Anthony; Motti, Cherie A

2012-03-23

From the organic extracts of two Guam sponges, Rhaphoxya sp. and Suberea sp., determined to have cytotoxic and chemopreventive activities, three new compounds, theonellin isocyanate (1) and psammaplysins I and J (5, 6), and six previously reported compounds (2-4, 7-9) were isolated and characterized spectroscopically ((1)H and (13)C NMR, MS, IR, UV, [α](D)). The two new metabolites (5 and 6) isolated from the Suberea sp. sponge are rare examples of compounds containing a bromotyramine moiety rather than the more usual dibromo analogue. For the compounds isolated from the Rhaphoxya sp., this is the first report of the known compounds 2-4 being found in a single sponge. For previously reported compounds 2-4 complete unambiguous (1)H and (13)C NMR data are provided.

Two spin-peierls-like compounds exhibiting divergent structural features, lattice compression, and expansion in the low- temperature phase.

PubMed

Tian, Zhengfang; Duan, Haibao; Ren, Xiaoming; Lu, Changsheng; Li, Yizhi; Song, You; Zhu, Huizhen; Meng, Qingjin

2009-06-18

Two quasi-one-dimensional (quasi-1D) compounds, [4'-CH(3)Bz-4-RPy][Ni(mnt)(2)] (mnt(2-) = maleonitriledithiolate), where 4'-CH(3)Bz-4-RPy(+) = 1-(4'-methylbenzyl)pyridinium (denoted as compound 1) and 1-(4'-methylbenzyl)-4-aminopyridinium (denoted as compound 2), show a spin-Peierls-like transition with T(C) approximately 182 K for 1 and T(C) approximately 155 K for 2. The enthalpy changes for the transition are estimated to be DeltaH = 316.6 J.mol(-1) for 1 and 1082.1 J.mol(-1) for 2. From fits to the magnetic susceptibility, the magnetic exchange constants in the gapless state are calculated to be J = 166(2) K with g = 2.020(23) for 1 versus J = 42(0) K with g = 2.056(5) for 2. In the high-temperature (HT) phase, 1 and 2 are isostructural and crystallize in the monoclinic space group P2(1)/c. The nonmagnetic cations and paramagnetic anions form segregated columns with regular anionic and cationic stacks. In the low-temperature (LT) phase, the crystals of the two compounds undergo a transformation to the triclinic space group P-1, and both anionic and cationic stacks dimerize. In the transformation from the HT to LT phases, the two compounds exhibit divergent structural features, with lattice compression for 1 but lattice expansion for 2, due to intermolecular slippage. Combined with our previous studies, it is also noted that the transition temperature, T(C), is qualitatively related to the cell volume in the HT phase for the series of compounds [1-(4'-R-benzylpyridinium][Ni(mnt)(2)] (where R represents the substituent). When there is a single substituent in the para position of benzene, giving a larger cell volume, the transition temperature increases.

Phase Behavior of Complex Superprotonic Solid Acids

NASA Astrophysics Data System (ADS)

Panithipongwut, Chatr

Superprotonic phase transitions and thermal behaviors of three complex solid acid systems are presented, namely Rb3H(SO4) 2-RbHSO4 system, Rb3H(SeO4)2-Cs 3H(SeO4)2 solid solution system, and Cs6 (H2SO4)3(H1.5PO4) 4. These material systems present a rich set of phase transition characteristics that set them apart from other, simpler solid acids. A.C. impedance spectroscopy, high-temperature X-ray powder diffraction, and thermal analysis, as well as other characterization techniques, were employed to investigate the phase behavior of these systems. Rb3H(SO4)2 is an atypical member of the M3H(XO4)2 class of compounds (M = alkali metal or NH4+ and X = S or Se) in that a transition to a high-conductivity state involves disproportionation into two phases rather than a simple polymorphic transition [1]. In the present work, investigations of the Rb3H(SO4)2-RbHSO4 system have revealed the disproportionation products to be Rb2SO 4 and the previously unknown compound Rb5H3(SO 4)4. The new compound becomes stable at a temperature between 25 and 140 °C and is isostructural to a recently reported trigonal phase with space group P3m of Cs5H 3(SO4)4 [2]. At 185 °C the compound undergoes an apparently polymorphic transformation with a heat of transition of 23.8 kJ/mol and a slight additional increase in conductivity. The compounds Rb3H(SeO4)2 and Cs 3H(SeO4)2, though not isomorphous at ambient temperatures, are quintessential examples of superprotonic materials. Both adopt monoclinic structures at ambient temperatures and ultimately transform to a trigonal (R3m) superprotonic structure at slightly elevated temperatures, 178 and 183 °C, respectively. The compounds are completely miscible above the superprotonic transition and show extensive solubility below it. Beyond a careful determination of the phase boundaries, we find a remarkable 40-fold increase in the superprotonic conductivity in intermediate compositions rich in Rb as compared to either end-member. The compound Cs6(H2SO4)3(H 1.5PO4)4 is unusual amongst solid acid compounds in that it has a complex cubic structure at ambient temperature and apparently transforms to a simpler cubic structure of the CsCl-type (isostructural with CsH2PO4) at its transition temperature of 100-120 °C [3]. Here it is found that, depending on the level of humidification, the superprotonic transition of this material is superimposed with a decomposition reaction, which involves both exsolution of (liquid) acid and loss of H2O. This reaction can be suppressed by application of sufficiently high humidity, in which case Cs6(H2SO4)3(H 1.5PO4)4 undergoes a true superprotonic transition. It is proposed that, under conditions of low humidity, the decomposition/dehydration reaction transforms the compound to Cs6(H2-0.5xSO 4)3(H1.5PO4)4-x, also of the CsCl structure type at the temperatures of interest, but with a smaller unit cell. With increasing temperature, the decomposition/dehydration proceeds to greater and greater extent and unit cell of the solid phase decreases. This is identified to be the source of the apparent negative thermal expansion behavior. References: [1] L.A. Cowan, R.M. Morcos, N. Hatada, A. Navrotsky, S.M. Haile, Solid State Ionics 179 (2008) (9-10) 305. [2] M. Sakashita, H. Fujihisa, K.I. Suzuki, S. Hayashi, K. Honda, Solid State Ionics 178 (2007) (21-22) 1262. [3] C.R.I. Chisholm, Superprotonic Phase Transitions in Solid Acids: Parameters affecting the presence and stability of superprotonic transitions in the MHnXO4 family of compounds (X=S, Se, P, As; M=Li, Na, K, NH4, Rb, Cs), Materials Science, California Institute of Technology, Pasadena, California (2003).

[The balance of harmful trace contaminants between the air humidity condensate and air in a simulator of the Mir orbit station moisture condensation unit].

PubMed

Zlotopol'skiĭ, V M; Smolenskaia, T S

2000-01-01

Subject of the investigation was the balance of harmful trace contaminants (HTC) between the air moisture condensate and air in a simulator of the MIR moisture condensation unit. Experiments involved various classes of water-solvent compounds including alcohols (C1-C4), ketons (C1-C2), aldehydes (C1-C2), fatty acids (C2-C4), esters (acetates C4-C6), and ammonium. For most of the compounds, removal efficiency correlates with air humidity and virtually does not depend on the HTC concentration within the range of 0.25 to 59.1 mg/m3.

Discovery of biaryl-4-carbonitriles as antihyperglycemic agents that may act through AMPK-p38 MAPK pathway.

PubMed

Goel, Atul; Nag, Pankaj; Rahuja, Neha; Srivastava, Rohit; Chaurasia, Sumit; Gautam, Sudeep; Chandra, Sharat; Siddiqi, Mohammad Imran; Srivastava, Arvind K

2014-08-25

A series of functionalized biaryl-4-carbonitriles was synthesized in three steps and evaluated for PTP-1B inhibitory activity. Among the synthesized compounds, four biaryls 6a-d showed inhibition (IC50 58-75 μM) against in vitro PTP-1B assay possibly due to interaction with amino acid residues Lys120, Tyr46 through hydrogen bonding and aromatic-aromatic interactions, respectively. Two biaryl-4-carbonitriles 6b and 6c showed improved glucose tolerance, fasting as well as postprandial blood glucose, serum total triglycerides, and increased high-density lipoprotein-cholesterol in SLM, STZ, STZ-S and C57BL/KsJ-db/db animal models. The bioanalysis of 4'-bromo-2,3-dimethyl-5-(piperidin-1-yl)biphenyl-4-carbonitrile (6b) revealed that like insulin, it increased 2-deoxyglucose uptake in skeletal muscle cells (L6 and C2C12 myotubes). The compound 6b significantly up-regulated the genes related to the insulin signaling pathways like AMPK, MAPK including glucose transporter-4 (GLUT-4) gene in muscle tissue of C57BL/KsJ-db/db mice. Furthermore, it was observed that the compound 6b up-regulated PPARα, UCP2 and HNF4α, which are key regulator of glucose, lipid, and fatty acid metabolism. Western blot analysis of the compound 6b showed that it significantly increased the phosphorylation of AMPK and p38 MAPK and ameliorated glucose uptake in C57BL/KsJ-db/db mice through the AMPK-p38 MAPK pathway. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Octahydropyrrolo[3,4-c]pyrrole negative allosteric modulators of mGlu1.

PubMed

Manka, Jason T; Rodriguez, Alice L; Morrison, Ryan D; Venable, Daryl F; Cho, Hyekyung P; Blobaum, Anna L; Daniels, J Scott; Niswender, Colleen M; Conn, P Jeffrey; Lindsley, Craig W; Emmitte, Kyle A

2013-09-15

Development of SAR in an octahydropyrrolo[3,4-c]pyrrole series of negative allosteric modulators of mGlu1 using a functional cell-based assay is described in this Letter. The octahydropyrrolo[3,4-c]pyrrole scaffold was chosen as an isosteric replacement for the piperazine ring found in the initial hit compound. Characterization of selected compounds in protein binding assays was used to identify the most promising analogs, which were then profiled in P450 inhibition assays in order to further assess the potential for drug-likeness within this series of compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

Discovery of novel pyrazolopyrimidinone analogs as potent inhibitors of phosphodiesterase type-5.

PubMed

Sawant, Sanghapal D; Lakshma Reddy, G; Dar, Mohd Ishaq; Srinivas, M; Gupta, Gourav; Sahu, Promod Kumar; Mahajan, Priya; Nargotra, Amit; Singh, Surjeet; Sharma, Subhash C; Tikoo, Manoj; Singh, Gurdarshan; Vishwakarma, Ram A; Syed, Sajad Hussain

2015-05-01

Cyclic guanosine monophosphate (cGMP) specific phosphodiesterase type-5 (PDE5), a clinically proven target to treat erectile dysfunction and diseases associated with lower cGMP levels in humans, is present in corpus cavernosum, heart, lung, platelets, prostate, urethra, bladder, liver, brain, and stomach. Sildenafil, vardenafil, tadalafil and avanafil are FDA approved drugs in market as PDE5 inhibitors for treating erectile dysfunction. In the present study a lead molecule 4-ethoxy-N-(6-hydroxyhexyl)-3-(1-methyl-7-oxo-3-propyl-6,7-dihydro-1H-pyrazolo[4,3-d]pyrimidin-5-yl)benzenesulfonamide, that is, compound-4a, an analog of pyrazolopyrimidinone scaffold has been identified as selective PDE5 inhibitor. A series of compounds was synthesized by replacing N-methylpiperazine moiety (ring-C) of sildenafil structure with different N-substitutions towards sulfonamide end. Compound-4a showed lower IC₅₀ value (1.5 nM) against PDE5 than parent sildenafil (5.6 nM) in in vitro enzyme assay. The isoform selectivity of the compound-4a against other PDE isoforms was similar to that of the Sildenafil. In corroboration with the in vitro data, this molecule showed better efficacy in in vivo studies using the conscious rabbit model. Also compound-4a exhibited good physicochemical properties like solubility, caco-2 permeability, cLogP along with optimal PK profile having no significant CYP enzyme inhibitory liabilities. Discovery of these novel bioactive compounds may open a new alternative for developing novel preclinical candidates based on this drugable scaffold. Copyright © 2015 Elsevier Ltd. All rights reserved.

Thieno[3,2-c]pyran-4-one based novel small molecules: their synthesis, crystal structure analysis and in vitro evaluation as potential anticancer agents.

PubMed

Nakhi, Ali; Adepu, Raju; Rambabu, D; Kishore, Ravada; Vanaja, G R; Kalle, Arunasree M; Pal, Manojit

2012-07-01

Novel thieno[3,2-c]pyran-4-one based small molecules were designed as potential anticancer agents. Expeditious synthesis of these compounds was carried out via a multi-step sequence consisting of few steps such as Gewald reaction, Sandmeyer type iodination, Sonogashira type coupling followed by iodocyclization and then Pd-mediated various C-C bond forming reactions. The overall strategy involved the construction of thiophene ring followed by the fused pyranone moiety and then functionalization at C-7 position of the resultant thieno[3,2-c]pyran-4-one framework. Some of the compounds synthesized showed selective growth inhibition of cancer cells in vitro among which two compounds for example, 5d and 6c showed IC(50) values in the range of 2.0-2.5 μM. The crystal structure analysis of an active compound along with hydrogen bonding patterns and molecular arrangement present within the molecule is described. Copyright © 2012 Elsevier Ltd. All rights reserved.

White Light Emission from Planar Remote Phosphor Based on NHC Cycloplatinated Complexes.

PubMed

Fuertes, Sara; Chueca, Andrés J; Perálvarez, Mariano; Borja, Pilar; Torrell, Marc; Carreras, Josep; Sicilia, Violeta

2016-06-29

We report on the generation of bright white luminescence through solid-state illumination of remote phosphors based on novel cycloplatinated N-heterocyclic carbene (NHC) compounds. Following a stepwise protocol we got the new NHC compound [{Pt(μ-Cl)(C(∧)C*)}2] (4) (HC(∧)C*-κC* = 1-(4-(ethoxycarbonyl)phenyl)-3-methyl-1H-imidazol-2-ylidene), which was used together with the related ones 4a (HC(∧)C*-κC*= 1-(4-cyanophenyl)-3-methyl-1H-imidazol-2-ylidene) and 4b (HC(∧)C*-κC*= 3-methyl-1-(naphthalen-2-yl)-1H-imidazol-2-ylidene) as starting materials for the synthesis of the new ionic derivatives [Pt(R-C(∧)C*) (CNR')2]PF6 (R = -COOEt, R' = t-Bu (5), Xyl (6); R = -CN, R' = t-Bu (7), Xyl (8); R(∧)C = Naph, R' = t-Bu (9), Xyl (10)). The X-ray structures of 6 and 8-10 have been determined. The photophysical properties of these cationic compounds have been studied and supported by the time-dependent-density functional theory (TD-DFT) calculations. The compounds 5, 8, and 9 have been revealed as the most efficient emitters in the solid state with quantum yields of 41%, 21%, and 40%, respectively. White-light remote-phosphors have been prepared just by stacking different combinations of these compounds and [Pt(bzq) (CN) (CN(t)Bu)] (R1) as blue (5, 8), yellow (9), and red (R1) components onto the same substrate. The CCT (correlated color temperature) and the CRI (color rendering index) of the emitted white-light have been tuned by accurately controlling the individual contributions.

Zwitterionic and free forms of arylmethyl Meldrum's acids.

PubMed

Mierina, Inese; Mishnev, Anatoly; Jure, Mara

2015-09-01

C-Alkyl (including C-arylmethyl) derivatives of Meldrum's acids are attractive building blocks in organic synthesis, mainly due to the unusually high acidity of the resulting compounds. Three examples, namely 5-[4-(diethylamino)benzyl]-2,2-dimethyl-1,3-dioxane-4,6-dione, C17H23NO4, (I), 2,2-dimethyl-5-(2,4,6-trimethoxybenzyl)-1,3-dioxane-4,6-dione, C16H20O7, (II), and 5-(4-hydroxy-3,5-dimethoxybenzyl)-2,2-dimethyl-1,3-dioxane-4,6-dione, C15H18O7, (III), have been synthesized, characterized by NMR and IR spectroscopy, and studied by single-crystal X-ray structure analysis. The nature of the different substituents resulted in remarkable differences in both the molecular conformations and the crystal packing arrangements. The presence of a substituent with a basic centre in compound (I) leads to the formation of an inner salt accompanied by drastic changes in the conformation of the 1,3-dioxane-4,6-dione fragment. By virtue of strong N-H···O hydrogen bonds, the residues are assembled into infinite chains with the graph-set descriptor C(10). Compound (II) contains methoxy groups in both the ortho- and para-positions of the arylmethyl fragment. Because of the absence of classical hydrogen-bond donors in this structure, the crystal packing is controlled by van der Waals forces and weak C-H···O interactions. Compound (III) contains methoxy groups in both meta-positions and a hydroxy group in the para-position. Supramolecular tetrameric synthons which comprise hydrogen-bonded dimers associated into tetramers through π-π interactions of overlapping benzene rings were observed.

Prenylated chalcones, flavone and other constituents of the twigs of Dorstenia angusticornis and Dorstenia barteri var. subtriangularis.

PubMed

Ngadjui, Bonaventure T; Watchueng, Jean; Keumedjio, Felix; Ngameni, Bathélémy; Simo, Ingrid K; Abegaz, Berhanu M

2005-03-01

The twigs of Dorstenia angusticornis and Dorstenia barteri var. subtriangularis yielded 16 compounds. Two novel diprenylated chalcones: 3,5'-di-(2-hydroxy-3-methylbut-3-enyl)-4,2',4'-trihydroxychalcone, 3, 4-(2,2-dimethylpyrano)-3'-(2-hydroxy-3-methylbut-3-enyl)-2',4'-dihydroxychalcone and the known stipulin were isolated from both species. 3-(2-Hydroxy-3-methylbut-3-enyl)-5'-(3,3-dimethylallyl)-4,2',4'-trihydroxychalcone and the known compounds: 4-hydroxylonchocarpin, kanzonol B, bartericins A, B, C and 3'-(2-hydroxy -3-methylbut-3-enyl)-4,2',4'-trihydroxychalcone were isolated from D. barteri while the known compounds: gancaonin Q, paratocarpins C, F, and lupeol were obtained from Dorstenia angusticornis. beta-Sitosterol and its beta-d-glucopyranoside were isolated from both species. Structures of these secondary metabolites were established using spectroscopic analysis, especially, NMR spectra in conjunction with 2D experiments, COSY, HMQC and HMBC.

Synthesis and Characterization of C-Cinnamal Calix [4] Resorsinarena from Cinnamon Oil Waste West Sumatra

NASA Astrophysics Data System (ADS)

Etika, S. B.; Nasra, E.; Rilaztika, I.

2018-04-01

Synthesis and characterization of compound C-Cinnamal Calix [4] Resorsinarena (CCCR) of cinnamon oil waste have been done. This study was aimed to synthesis and characterize C-Cinnamal Calix [4] Resorsinarena from cinnamaldehyde violated cinnamon oil waste. C-Cinnamal Calix [4] Resorsinarena was synthesized by electrophilic substitution reaction of cinnamaldehyde isolated by the acid and resorcinol at 77oC temperature for 2 hour. The data analysis spectrum UV-VIS and FT-IR showed that the compound isolated cinnamaldehyde same as pure cinnamaldehyde compound. The characterization of C-Cinnamal Calix [4] Resorsinarena in the form of reddish-colored solids with melting point 3580C by using UV-VIS showed the presence of double bond, FT-IR showed the absorption at the wave number 3323,94 cm-1 indicating the ‑OH group, the wave number 1610,94 cm-1 showed the vibration C=C, the strong region absorption of 1500,86 cm-1 indicating the presence of an aromatic ring, the at 1442,88 cm-1 wave number indicating the presence of CH3.

Cytotoxic and antioxidant constituents from the leaves of Psidium guajava.

PubMed

Feng, Xiao-He; Wang, Zi-Hao; Meng, Da-Li; Li, Xian

2015-01-01

Psidium guajava (Myrtaceae) is an evergreen shrub growing extensively throughout the tropical and subtropical areas. Four new compounds, guavinoside C, D, E and F (1-3, 10) were isolated from the leaves of P. guajava, along with six known ones (4-9). Their structures were elucidated by spectroscopic analysis. Compounds 1, 4 and 10 showed significant cytotoxic activities on HeLa, SGC-7901 and A549 cell lines, respectively. Compounds 1 and 4-10 showed antioxidant activities in DPPH, ABTS and FRAP assays, and five of them (1, 4-6, 10) exhibited stronger activities than that of vitamin C. Copyright © 2015 Elsevier Ltd. All rights reserved.

Design, synthesis, characterisation, conformation and biological investigation of N-acyl r-2,c-6-bis (4-methoxyphenyl)-c-3,t-3-dimethylpiperidin-4-ones

NASA Astrophysics Data System (ADS)

Mohanraj, V.; Ponnuswamy, S.

2017-09-01

In a wide research programme towards the study of piperidin-4-ones with efficient pharmacological effect, a new series of N-acyl r-2,c-6-bis(4-methoxyphenyl)-c-3,t-3-dimethylpiperidin-4-ones 2-5 are synthesized and characterized by IR spectra, 1H, 13C, DEPT - 135 and 2D (COSY and HSQC) NMR and mass spectra. The parent compound 1 prefers to exist in a chair conformation whereas the extracted coupling constant, chemical shifts and estimated dihedral angles show that the N-acyl piperdine-4-ones 2-5 prefer to exist in a distorted boat conformation B1 (with C2 and C5 in prow and stern positions) with coplanar orientation of Nsbnd Cdbnd O moiety. The existence of a fast Nsbnd CO rotational equilibrium between the boat conformations B (I) and B (II) has also been observed. Anti bacterial activity of the above test compounds 1-5 is determined against pseudomonas sp. and salmonella sp. The antioxidant activities are determined by the ABTS, DPPH and superoxide assays. Furthermore, molecular docking studies have been carried out for the compounds 1-5 with target protein CHK1.

Crystal structures, vibrational spectra and DFT calculations of five halogeno-derivatives of 7-azaindole (3Br7AI, 4Br7AI, 4Cl7AI, 3Br4Cl7AI and 5Br3Cl7AI): a comparative study

NASA Astrophysics Data System (ADS)

Morzyk-Ociepa, Barbara; Dysz, Karolina; Turowska-Tyrk, Ilona; Michalska, Danuta

2018-01-01

Structures and vibrational spectra of 3-bromo-7-azaindole (3Br7AI), 4-bromo-7-azaindole (4Br7AI), 4-chloro-7-azaindole (4Cl7AI), 5-bromo-3-chloro-7-azaindole (5Br3Cl7AI) and 3-bromo-4-chloro-7-azaindole (3Br4Cl7AI) have been investigated. For the first time a single crystal analysis is reported for the three compounds: 3Br7AI (P21/n space group; a = 12.6586(3), b = 3.98664(12), c = 14.1189(4)Å, β = 100.901(2)o, Z = 4); 4Br7AI (P21/n space group; a = 5.38136 (13), b = 9.2262 (2), c = 13.9806 (4)Å, β = 90.052 (2)o, Z = 4); and 5Br3Cl7AI (C2/c space group; a = 22.9444(10), b = 3.91953(12), c = 17.8500(6)Å, β = 102.621(4)o, Z = 8). In the crystal structure, a pair of molecules forms a centrosymmetric dimer connected by dual nearly linear Nsbnd H⋯N hydrogen bonds between the pyrrole and pyridine rings. In addition, the structures of 4Br7AI and 5Br3Cl7AI are stabilized by C2sbnd H2⋯Br hydrogen bonds. The IR and Raman spectra of all compounds and their N-deuterated derivatives were recorded in the solid state. The theoretical molecular structures and vibrational spectra of the centrosymmetric dimers of five investigated compounds were calculated using the B3LYP method with the 6-311G++(d,p) basis set. The optimized structural parameters and the calculated vibrational spectra reproduce well the experiment. Detailed vibrational assignments for all these compounds have been made on the basis of the calculated potential energy distributions (PEDs). The characteristic marker bands for the chloro- and bromo-derivativeds of 7-azaindoles are reported.

Synthesis and In Vitro Antimicrobial Evaluation of New 1,3,4-Oxadiazoles Bearing 5-Chloro-2-methoxyphenyl Moiety.

PubMed

Prasanna Kumar, Basavapatna N; Mohana, Kikkeri N; Mallesha, Lingappa; Harish, Kikkeri P

2013-01-01

A series of new 1,3,4-oxadiazole derivatives, 4(a-h), containing 5-chloro-2-methoxy benzohydrazide moiety were synthesized by the reaction of 5-chloro-2-methoxybenzoate with different aromatic carboxylic acids. These newly synthesized compounds were characterized by FT-IR, (1)H NMR, mass spectra, and also by elemental analysis. All the newly synthesized compounds were screened for their antibacterial and antifungal activities. Antimicrobial studies revealed that compounds 4c, 4f, and 4g showed significant activity against tested strains.

Synthesis, DNA binding ability and anticancer activity of 2-heteroaryl substituted benzimidazoles linked pyrrolo[2,1-c][1,4]benzodiazepine conjugates.

PubMed

Kamal, Ahmed; Pogula, Praveen Kumar; Khan, Mohammed Naseer Ahmed; Seshadri, Bobburi Naga; Sreekanth, Kokkonda

2013-08-01

As a continuation of our efforts to develop the benzimidazole-PBD conjugates as potential anticancer agents, a series of heteroaryl substituted benzimidazole linked PBD conjugates has been synthesized and evaluated for their anticancer potential in 60 human cancer cell lines. Most of the compounds exhibited promising anticancer activity and interestingly, compounds 4c and 4d displayed significant activity in most of the cell lines tested. Whereas, compound 4e showed selectivity in renal cancer cells with GI50 values of <10 and 70 nM against RXF 393 and UO-31 cell lines, respectively. Further, these compounds also showed significant DNA-binding affinity by thermal denaturation study using duplex form of calf thymus (CT) DNA.

BAC-MP4 predictions of thermochemistry for the gas-phase tin compounds in the Sn-H-C-Cl system.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allendorf, Mark D.; Melius, Carl F.

2004-09-01

In this work, the BAC-MP4 method is extended for the first time to compounds in the fourth row of the periodic table, resulting in a self-consistent set of thermochemical data for 56 tin-containing molecules in the Sn-H-C-Cl system. The BAC-MP4 method combines ab initio electronic structure calculations with empirical corrections to obtain accurate heats of formation. To obtain electronic energies for tin-containing species, the standard 6-31G(d,p) basis set used in BAC-MP4 calculations is augmented with a relativistic effective core potential to describe the electronic structure of the tin atom. Both stable compounds and radical species are included in this study.more » Trends within homologous series and calculated bond dissociation energies are consistent with previous BAC-MP4 predictions for group 14 compounds and the limited data available from the literature, indicating that the method is performing well for these compounds.« less

Synthesis, crystal structure, Hirshfeld surfaces analysis and anti-ischemic activity of cinnamide derivatives

NASA Astrophysics Data System (ADS)

Zhong, Jian-gang; Han, Jia-pei; Li, Xiao-feng; Xu, Yi; Zhong, Yan; Wu, Bin

2018-02-01

Two cinnamide derivatives, namely, (E)-1-(4-(bis(4-methylphenyl)- methyl)piperazin-1-yl)-3-(3,4-diethoxyphenyl)prop-2-en-1-one (5) and (E)-1-(4-(bis- (4-fluorophenyl)methyl)piperazin-1-yl)-3-(4-methoxyphenyl)prop-2-en-1-one (6), have been synthesized and characterized by IR spectra, High resolution mass spectra, 1H NMR spectra, 13C NMR spectra. The compound 5 is a novel compound and has never been reported in the literature. Their crystal structures were studied by single-crystal X-ray diffraction. They all crystallize in the monoclinic system. The single-crystal X-ray revealed that compound 5 has infinite X-shaped 1-D polymeric chains structure and compound 6 has a layered 3-D structure by intermolecular interactions. Hirshfeld surface analysis demonstrated the presence of H⋯H, O⋯H, C⋯H, F⋯H, Csbnd H⋯π and π⋯π intermolecular interactions. In addition, the MTT assay results indicated that the compounds 5 and 6 display effective activities against neurotoxicity which is induced by glutamine in PC12 cells. The in vivo experiment indicated that the compound 6 has a good protective effect on cerebral infarction.

[The compounds from n-butanol fraction of Alpinia oxyphylla].

PubMed

Xie, Bin-Bin; Hou, Lei; Guo, Bao-Lin; Huang, Wen-Hua; Yu, Jing-Guang

2014-11-01

Nine compounds were isolated from the n-butanol fraction of 95% ethanol extract of the fruit of Alpinia oxyphylla Miq. with a combination of various chromatographic approaches, including MDS resin, silica gel, reverse phase C18 and preparative HPLC. On the basis of spectroscopic data analysis, they were elucidated as (1R, 4R, 10R)-1β, 4α-dihydroxy-11, 12, 13-trinor-5, 6-eudesmen-7-one (1), 1β, 4β-dihydroxy-11, 12, 13-trinor-8, 9-eudesmen-7-one (2), oxyphyllenone A (3), oxyphyllenone B (4), rhamnocitrin (5), staphylionoside D (6), benzyl-1-O-β-D-glucopyranoside (7), 2-O-β-D-glucopyranosyl-(1S)-phenylethylene glycol (8), and (S)-1-phenylethyl-β-D-glucopyranoside (9). Among them, compound 1 is a new sesquiterpene, named as oxyphyllenone C; compounds 8 and 9 are new natural products; compounds 2 and 6 were isolated from the genus Alpinia for the first time, and compound 7 was isolated from A. oxyphylla for the first time.

Associations of dioxins, furans and dioxin-like PCBs with diabetes and pre-diabetes: is the toxic equivalency approach useful?

PubMed

Everett, Charles J; Thompson, Olivia M

2012-10-01

Toxic equivalency factors for dioxins and dioxin-like compounds have been established by the World Health Organization. Toxic equivalency (TEQ) was derived using 6 chlorinated dibenzo-p-dioxins, 9 chlorinated dibenzofurans and 8 polychlorinated biphenyls, in blood, from the 1999-2004 National Health and Nutrition Examination Survey. Relationships of 8 individual chemicals, the number of compounds elevated, and TEQ with pre-diabetes and total diabetes (diagnosed and undiagnosed) were investigated using logistic regressions. For the 8 chemicals analyzed separately, values above the 75th percentile were considered elevated, whereas for the other 15 compounds, values above the maximum limit of detection were considered elevated. Pre-diabetes with glycohemoglobin (A1c) 5.9-6.4% was associated with PCB 126, PCB 118 and having one or more compounds elevated (odds ratio 2.47, 95% CI 1.51-4.06). Pre-diabetes with A1c 5.7-5.8% was not associated with any individual chemical or the number of compounds elevated. Total diabetes was associated with 6 of the 8 individual compounds tested, and was associated with having 4 or more compounds elevated. Toxic equivalency ≥81.58 TEQ fg/g was associated with total diabetes (odds ratio 3.08, 95% CI 1.20-7.90), but was not associated with A1c 5.9-6.4%. Having multiple compounds elevated appeared to be important for total diabetes, whereas for pre-diabetes with A1c 5.9-6.4%, having a single compound elevated appeared most important. Diabetes plus A1c ≥5.9% was associated with 34.16-81.57 TEQ fg/g (odds ratio 2.00, 95% CI 1.06-3.77) and with ≥81.58 TEQ fg/g (odds ratio 2.48, 95% CI 1.21-5.11), indicating that half the population has elevated risk for this combination of conditions. Copyright © 2012 Elsevier Inc. All rights reserved.

Mercury(II) complexes of unsymmetric phosphorus ylides: Synthesis, spectroscopic and antibacterial activity studies

NASA Astrophysics Data System (ADS)

Sabounchei, Seyyed Javad; Panahimehr, Mohammad; Hosseinzadeh, Marjan; Karamian, Roya; Asadbegy, Mostafa; Masumi, Azadeh

2014-03-01

The reaction of Ph2PCH2PPh2 (dppm) with 2-bromo-3-nitroacetophenone and 2,2‧,4‧-trichloroacetophenone in chloroform produce the new phosphonium salts [Ph2PCH2PPh2CH2C(O)C6H4NO2]Br (1) and [Ph2PCH2PPh2CH2C(O)C6H3Cl2]Cl (2). Further, by reaction of the monophosphonium salts of dppm with the strong base triethylaminethe corresponding bidentate phosphorus ylides, Ph2PCH2PPh2C(H)C(O)C6H4NO2 (3) and Ph2PCH2PPh2C(H)C(O)C6H3Cl2 (4) were obtained. The reaction of these ligands with mercury(II) halides in dry methanol led to the formation of the mononuclear complexes {HgX2[(Ph2PCH2PPh2C(H)C(O)C6H4NO2)]} [X = Cl (5), Br (6), I (7)] and {HgX2[(Ph2PCH2PPh2C(H)C(O)C6H3Cl2)]} [X = Cl (8), Br (9), I (10)]. Characterization of the obtained compounds was performed by elemental analysis, IR, 1H, 31P and 13C NMR. The structure of compound 1 being unequivocally determined by single crystal X-ray diffraction techniques. The mass spectrum of compound 6 (as an instance) also demonstrates the synthesize of these compounds. In all complexes the title ylides are coordinated through the ylidic carbon and the phosphine atom. These compounds form five membered ring under complexation. The antibacterial effects of DMSO solutions of the ligands and their metal complexes were evaluated by the disc diffusion method against six Gram positive and negative bacteria. All compounds represent antibacterial activity against these bacteria with high levels of inhibitory potency exhibited against the Gram positive species.

Synthesis, photochemical synthesis and antitumor evaluation of novel derivatives of thieno[3',2':4,5]thieno[2,3-c]quinolones.

PubMed

DoganKoruznjak, Jasna; Slade, Neda; Zamola, Branimir; Pavelić, Kresimir; Karminski-Zamola, Grace

2002-05-01

The novel derivatives of thieno[3',2':4,5]thieno[2,3-c]quinolones 6a, 6b, 7, 10a and 10b were synthesized in multistep synthesis starting from thiophene-3-carboxaldehyde and malonic acid reacting in aldol condensation or from 3-bromothiophenes or methyl 4-bromothiophene-2-carboxylate reacting in Heck reaction. They resulted in corresponding substituted thienylacrylic acids 3a-c, which were cyclized into thieno[2,3-c]thiophene-2-carbonyl chlorides 4a-c and converted into thieno[2,3-c]thiophene-2-carboxamides 5a-d. Prepared carboxamides were photochemically dehydrohalogenated into corresponding substituted thieno[3',2':4,5]thieno[2,3-c]quinolones 6a-d. Compound 7 was prepared from 6d by alkylation with N-[3-(dimethylamino)propyl]chloride hydrochloride in the presence of NaH. Compounds 10a and 10b were prepared from 6c in the multistep synthesis over acid 8 and acid chloride 9. Compounds 6a, 6b, 7, 10a and 10b were found to exert cytostatic activities against malignant cell lines: pancreatic carcinoma (MiaPaCa2), breast carcinoma (MCF7), cervical carcinoma (HeLa), laryngeal carcinoma (Hep2), colon carcinoma (CaCo-2), melanoma (HBL), and human fibroblast cell lines (WI-38). The compound 6b, which bears the 3-dimethylaminopropyl substituent on quinolone nitrogen and methoxycarbonyl substituent on position 9, exhibited marked antitumor activity. On the contrary, compound 7, which also bears the 3-dimethylaminopropyl substituent on the quinolone nitrogen but anilido substituent on position 9, exhibited less antitumor activity than the others.

Synthesis, characterization and thermal decomposition of tetramethylammonium rare earth double selenates

NASA Astrophysics Data System (ADS)

Divekar, Sandesh K.; Achary, S. Nagabhusan; Ajgaonkar, Vishnu R.

2018-06-01

A series of double selenates, as (CH3)4NLn(SeO4)2rad 4H2O (Ln = Rare earth ion like La, Pr, Nd, Sm, Gd, Tb, Dy) was crystallized from mixed solution and characterized in detail for their structure, vibrational and optical properties as well as thermal stabilities. The crystal structure of the praseodymium compound was obtained by single crystal X-ray diffraction (XRD) and revealed a monoclinic (C2/c) lattice with chains formed by PrO8 and SeO4 units. The chains with compositions [Pr(SeO4)4(H2O)4]- are stacked in three dimensions and the (CH3)4N+ ions located in between them provide charge neutrality to the structure. The characterization of other compounds were carried out from powder XRD data and revealed that they all are isostructural to Pr-compound. All the functional groups were identified by Raman and IR spectroscopic studies. Solid state 77Se NMR revealed noticeable changes in selenium environment in these compounds. The optical absorption studies on the compounds show strong band edge absorptions in UV region. Thermal stabilities of the compounds, as investigated by simultaneous TG-DTA techniques indicate their sequential decompositions due to loss of H2O, (CH3)4N+ group, SeO2 and finally leaving their corresponding rare earth oxides.

Triple-decker sandwiches and related compounds of the first-row transition metals containing cyclopentadienyl and benzene rings.

PubMed

Liu, Haibo; Li, Qian-shu; Xie, Yaoming; King, R Bruce; Schaefer, Henry F

2010-08-12

The triple-decker sandwich compound trans-Cp(2)V(2)(eta(6):eta(6)-mu-C(6)H(6)) has been synthesized, as well as "slipped" sandwich compounds of the type trans-Cp(2)Co(2)(eta(4):eta(4)-mu-arene) and the cis-Cp(2)Fe(2)(eta(4):eta(4)-mu-C(6)R(6)) derivatives with an Fe-Fe bond (Cp = eta(5)-cyclopentadienyl). Theoretical studies show that the symmetrical triple-decker sandwich structures trans-Cp(2)M(2)(eta(6):eta(6)-mu-C(6)H(6)) are the global minima for M = Ti, V, and Mn but lie approximately 10 kcal/mol above the global minimum for M = Cr. The nonbonding M...M distances and spin states in these triple decker sandwich compounds can be related to the occupancies of the frontier bonding molecular orbitals. The global minimum for the chromium derivative is a singlet spin state cis-Cp(2)Cr(2)(eta(4):eta(4)-mu-C(6)H(6)) structure with a very short CrCr distance of 2.06 A, suggesting a formal quadruple bond. A triplet state cis-Cp(2)Cr(2)(eta(4):eta(4)-mu-C(6)H(6)) structure with a predicted Cr[triple bond]Cr distance of 2.26 A lies only approximately 3 kcal/mol above this global minimum. For the later transition metals the global minima are predicted to be cis-Cp(2)M(2)(eta(6):eta(6)-mu-C(6)H(6)) structures with a metal-metal bond, rather than triple decker sandwiches. These include singlet cis-Cp(2)Fe(2)(eta(4):eta(4)-mu-C(6)H(6)) with a predicted Fe=Fe double bond distance of 2.43 A, singlet cis-Cp(2)Co(2)(eta(3):eta(3)-mu-C(6)H(6)) with a predicted Co-Co single bond distance of 2.59 A, and triplet cis-Cp(2)Ni(2)(eta(3):eta(3)-mu-C(6)H(6)) with a predicted Ni-Ni distance of 2.71 A.

Synthetic, Infrared, 1Hand 13CNMR Spectral Studies on N-(p-Substituted Phenyl)-p-Substituted Benzenesulphonamides, p-X'C6H4SO2NH- (p-XC6H4), where X' or X = H, CH3, C2H5, F, Cl or Br

NASA Astrophysics Data System (ADS)

Gowda, B. Thimme; Jayalakshmi, K. L.; Shetty, Mahesha

2004-05-01

Thirty N-(p-substituted phenyl)-p-substituted benzenesulphonamides of the general formula, p-X'C6H4SO2NH(p-XC6H4), where X' or X = H, CH3, C2H5, F, Cl or Br, are synthesised and their infrared spectra in the solid state and 1H and 13C NMR spectra in solution are measured. The N-H stretching vibrational frequencies, νN-H vary in the range 3334 - 3219 cm-1, while the asymmetric and symmetric SO2 vibrations appear in the ranges 1377 - 1311 cm-1 and 1182 - 1151 cm-1, respectively. The compounds exhibit S-N and C-N stretching vibrational absorptions in the ranges 937 - 898 cm-1 and 1310 - 1180 cm-1, respectively. There are no particular trends in the variation of these frequencies on substitution with either electron withdrawing or electron donating groups. The 1H and 13C chemical shifts of N-(p-substituted phenyl)-p-substituted benzenesulphonamides, are assigned to various protons and carbons of the two benzene rings. Further, incremental shifts of the ring protons and carbons due to -SO2NH(p-XC6H4) groups in the compounds of the formula, C6H5SO2NH(p-XC6H4), and p-X'C6H4SO2- and p-X'C6H4SO2NH- groups in the compounds of the formula, p-X'C6H4SO2NH(C6H5) are computed and used to calculate the 1H and 13C chemical shifts of the parallely substituted compounds of the general formula p-X'C6H4SO2NH(p-XC6H4). The computed values agree well with the observed chemical shifts. The above incremental shifts are found to correlate with the Hammett substituent parameters.

Synthesis, Characterization, and Antimicrobial Activity of a Novel Trisazo Dye from 3-Amino-4H-thieno[3,4-c][1]benzopyran-4-one.

PubMed

Tsemeugne, Joseph; Sopbué Fondjo, Emmanuel; Tamokou, Jean-de-Dieu; Rohand, Taoufik; Ngongang, Arnaud Djintchui; Kuiate, Jules Roger; Sondengam, Beibam Luc

2018-01-01

A new trisazo dye has been synthesized by coupling the diazonium ion of 3-amino-4H thieno[3,4-c][1]benzopyran-4-one with 2- tert -butyl-4-methoxyphenol. The newly prepared trisazo dye was characterized by its physical, elemental, and spectroscopic data. 2D-NMR (COSY, HSQC, and HMBC) techniques were used to secure the structural assignments. The new trisazo dye (compound 7 ) along with precursors 3 , 4 , and 6 was screened by microdilution susceptibility assay for antibacterial and antifungal activities towards eight bacterial strains and three yeasts selected on the basis of their relevance as human pathogens. The results showed that compound 7 (MIC = 2-128  μ g/mL) was the most active as compared with its precursors. The most resistant microorganisms were V. cholerae NB2 and V. cholerae SG24, whereas the most sensitive microorganism was C. neoformans. The overall results of this study indicated that compound 7 had the greatest potential value against both yeasts and multidrug-resistant bacteria, so further investigation is warranted.

Synthesis, Characterization, and Antimicrobial Activity of a Novel Trisazo Dye from 3-Amino-4H-thieno[3,4-c][1]benzopyran-4-one

PubMed Central

Tsemeugne, Joseph; Rohand, Taoufik; Ngongang, Arnaud Djintchui; Sondengam, Beibam Luc

2018-01-01

A new trisazo dye has been synthesized by coupling the diazonium ion of 3-amino-4H thieno[3,4-c][1]benzopyran-4-one with 2-tert-butyl-4-methoxyphenol. The newly prepared trisazo dye was characterized by its physical, elemental, and spectroscopic data. 2D-NMR (COSY, HSQC, and HMBC) techniques were used to secure the structural assignments. The new trisazo dye (compound 7) along with precursors 3, 4, and 6 was screened by microdilution susceptibility assay for antibacterial and antifungal activities towards eight bacterial strains and three yeasts selected on the basis of their relevance as human pathogens. The results showed that compound 7 (MIC = 2–128 μg/mL) was the most active as compared with its precursors. The most resistant microorganisms were V. cholerae NB2 and V. cholerae SG24, whereas the most sensitive microorganism was C. neoformans. The overall results of this study indicated that compound 7 had the greatest potential value against both yeasts and multidrug-resistant bacteria, so further investigation is warranted. PMID:29484208

Phase equilibria in the Tb-Mg-Co system at 500 °C, crystal structure and hydrogenation properties of selected compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shtender, V.V.; Denys, R.V.; Zavaliy, I.Yu., E-mail: zavaliy@ipm.lviv.ua

2015-12-15

The isothermal section of the Tb–Mg–Co phase diagram at 500 °C has been built on the basis of XRD analysis of forty samples prepared by powder metallurgy. The existence of two ternary compounds Tb{sub 4}Mg{sub 3}Co{sub 2} and Tb{sub 4}MgCo was confirmed. The formation of two solid solutions, Tb{sub 1−x}Mg{sub x}Co{sub 3} (0≤x≤0.4) and Tb{sub 1-−x}Mg{sub x}Co{sub 2} (0≤x≤0.6), was found for the first time. It is shown that Tb{sub 5}Mg{sub 24} also dissolves a small amount of Co. Other binary compounds do not dissolve the third component. The Tb{sub 4}MgCo and TbMgCo{sub 4} compounds form hydrides (12.7 and 5.3more » at.H/f.u. capacity, respectively) that retain the original structure of metallic matrices. Upon thermal desorption the Tb{sub 4}MgCoH{sub 12.7} hydride was stable up to 300 °C and disproportionated at higher temperature. Two other hydrides, Tb{sub 4}Mg{sub 3}Co{sub 2}H{sub ∼4} and Tb{sub 2}MgCo{sub 9}H{sub 12}, are unstable in air and decompose into the initial compounds. - Highlights: • The phase equilibria at 500 °°C in the Tb–Mg–Co system has been studied. • The existence of two ternary compounds, Tb{sub 4}Mg{sub 3}Co{sub 2} and Tb{sub 4}MgCo, was confirmed. • The formation of two solid solutions, Tb{sub 1−x}Mg{sub x}Co{sub 3} and Tb{sub 1−x}Mg{sub x}Co{sub 2}, was found. • Hydrogen sorption–desorption properties have been studied for the selected alloys.« less

A New Metabolite with a unique 4-pyranone-ylactam-1,4-thiazine moiety from a Hawaiian-plant associated fungus

USDA-ARS?s Scientific Manuscript database

An endophytic fungus Paraphaeosphaeria neglecta FT462 isolated from the Hawaiian-plant Lycopodiella cernua (L.) Pic. Serm produced one unusual compound (1, paraphaeosphaeride A) with the 4-pyranone-'-lactam-1,4-thiazine moiety, along with two new compounds (2 and 3, paraphaeosphaerides B and C, resp...

Reaction of cytochrome c with nitrite and nitric oxide. A model of dissimilatory nitrite reductase.

PubMed

Orii, Y; Shimada, H

1978-12-01

The reaction of bovine heart ferrocytochrome c with nitrite was studied under various conditions. The reaction product was ferricytochrome c at around pH 5, whereas at around pH 3 it was Compound I, characterized by twin peaks at 529 and 563 nm of equal intensity. However, ferrocytochrome c decreased obeying first-order kinetics over the pH range examined, irrespective of the presence or absence of molecular oxygen. The apparent first-order rate constant was proportional to the square of the nitrite concentration at pH 4.4 and it increased as the pH was lowered. At pH 3 the reaction was so rapid that it had to be followed by stopped-flow and rapid-scanning techniques. The apparent rate constant at this pH was found to increase linearly with the nitrite concentration. Based on these results the active species of nitrite was concluded to be dinitrogen trioxide at pH 4.4 and nitrosonium ion, no+, at pH 3. Compound II was formed by reaction of ferrocytochrome c and NO gas at acidic and alkaline pH values. The absorption peaks were at 533 and 563 nm at pH 3, and at 538 and 567 nm at pH 12.9. This compound was also formed by reducing Compound I with reductants. Compound I prepared from ferricytochrome c and NO was stable below pH 6. However, appreciable absorption peaks for ferrocytochrome c appeared between pH 8 and 10, because Compound I was dissociated into ferrocytochrome c and NO+, and because ferrocytochrome c thus formed reacted with NO very slowly in this pH region. Saccharomyces ferricytochrome c under NO gas behaved differently from mammalian cytochrome, indicating the significance of the nature of the heme environment in determing the reactivity. Only at extreme pH values was Compound II formed exclusively and persisted. A model system for dissimilatory nitrite reductase was constructed by using bovine heart cytochrome c, nitrite and NADH plus PMS at pH 3.3, and a scheme involving cyclic turnover of ferrocytochrome c, Compound I and Compound II is presented, with kinetic parameters.

Transannular sulfur-nitrogen interaction in 1,5-thiazocine derivatives: an X-ray study

NASA Astrophysics Data System (ADS)

Kuti, M.; Rábai, J.; Kapovits, I.; Jalsovszky, I.; Argay, Gy.; Kálmán, A.; Párkányi, L.

1996-08-01

7-Acetylbenzo[ b]naphtho[1,8- f, g]thiazocin-8(7 H)-onesulfide- N-acetyllactam 3) and its 13-oxide (sulfoxide- N-acetyl-lactam 4, exhibiting polymorphy, 4a and 4b) have been prepared and their structures established by X-ray crystallography from diffractometer data. Compound 3 (C 19H 13NO 2S) crystallizes in the monoclinic space group {P2 1}/{c} with a = 10.716(3), b = 9.222(2), c = 16.077(5) Å, β = 106.68(2)°, V = 1521.9(7) Å3, Z = 4, Dc = 1.394 g cm -3 and μ(Mo K α) = 0.22 mm -1. Compound 4a (C 19H 13NO 3S) crystallizes in the monoclinic space group Pc with a = 7.821(1), b = 24.795(6), c = 8.342(1) Å, β = 101.15(1)°, V = 1587.2(4) Å3, Z = 4 (two molecules, 4a' and 4a″, in the asymmetric unit), Dc = 1.40 g cm -3 and μ(Mo K α) = 0.21 mm -1. Compound 4b also crystallizes in the monoclinic space group {P2 1}/{c} with a = 11.791(1), b = 10.719(1), c = 25.193(2) Å, β = 96.02(1)°, V = 3166.4(4) Å3, Z = 8 (two molecules, 4b' and 4b″ in the asymmetric unit), Dc = 1.394 g cm -3 and μ(Cu K α) = 1.92 mm -1. The crystal structures were solved by direct methods and refined to R = 0.052 for 3, R = 0.088 for 4a, and R = 0.048 for 4b, by using 9413, 4759 and 5195 reflections, respectively. Owing to the cis-amide structure, compounds 3 and 4 assume a boat-like conformation with transannular sulfur-nitrogen close contact; r( S…N) = 2.968(1) Å for 3 and 2.753(3)-2.832(2) Å for 4a' and 4b″. The out-of-ring position of the sulfinyl oxygen leads to a sulfurane-like trigonal bipyramidal geometry about sulfur in in 4a' and 4b″; θ(OS…N) = 175.8(3)-178.7(2)°. The interatomic distances r( SO) = 1.483(2)-1.498(3) Å and r( OS…N) = 4.245-4.314 Å are in agreement with an SO double bond and S…N close contact rather than with an OSN type molecular structure observed in spirosulfuranes. The stereochemistries of 1,5-thiazocine and 1,5-thiazonine rings are compared.

Synthesis, electronic structure, and reactivity of strained nickel-, palladium-, and platinum-bridged [1]ferrocenophanes.

PubMed

Matas, Inmaculada; Whittell, George R; Partridge, Benjamin M; Holland, Jason P; Haddow, Mairi F; Green, Jennifer C; Manners, Ian

2010-09-29

The group 10 bis(phosphine)metalla[1]ferrocenophanes, [{Fe(η(5)-C(5)H(4))(2)}M(Pn-Bu(3))(2)] [M = Ni (4a), Pd (4b), and Pt (4c)], have been prepared by the reaction of Li(2)[Fe(η(5)-C(5)H(4))(2)]·tmeda (5, tmeda = N,N,N',N'-tetramethylethylenediamine) with trans-[MCl(2)(Pn-Bu(3))(2)] [M = Ni (trans-6a) and Pd (trans-6b)] and cis-[PtCl(2)(Pn-Bu(3))(2)] (cis-6c), respectively. Single crystal X-ray diffraction revealed highly tilted, strained structures as characterized by α angles of 28.4° (4a), 24.5° (4b), and 25.2° (4c) and a distorted square planar environment for the group 10 metal center. UV/visible spectroscopy and cyclic voltammetry indicated that all three compounds had smaller HOMO-LUMO gaps and were more electron-rich in nature than ferrocene and other comparable [1]ferrocenophanes. DFT calculations suggested that these differences were principally due to the electron-releasing nature of the M(Pn-Bu(3))(2) metal-ligand fragments. Attempts to induce thermal or anionic ring-opening polymerization of 4a-c were unsuccessful and were complicated by, for example, competing ligand dissociation processes or unfavorable chain propagation. In contrast, these species all reacted rapidly with acids effecting clean extrusion of the bis(phosphine)metal fragment. Carbon monoxide inserted cleanly into one of the palladium-carbon bonds of 4b to afford the ring-expanded, acylated product [{Fe(η(5)-C(5)H(4))(η(5)-C(5)H(4))(CO)}Pd(Pn-Bu(3))(2)] (10). The nickel analogue 4a, however, afforded [Ni(CO)(2)(Pn-Bu(3))(2)] whereas the platinum-bridged complex 4c was inert. Remarkably, all compounds 4a-c were readily oxidized by elemental sulfur to afford the [5,5']bicyclopentadienylidene (pentafulvalene) complexes [{η(4):η(0)-C(5)H(4)(C(5)H(4))}M(Pn-Bu(3))(2)] [M = Ni (11a)] and [(η(2)-C(10)H(8))M(Pn-Bu(3))(2)] [M = Pd (11b) and Pt (11c)] by a formal 4-electron oxidation of the carbocyclic ligands. Compounds 11b and 11c represent the first examples of [5,5']bicyclopentadienylidene as a neutral η(2)-ligand. The relative energies of η(2)-coordination with respect to that of η(4):η(0) bonding were investigated for 11a-c by DFT calculations.

Spectroscopic characterization, antimicrobial activity and molecular docking study of novel azo-imine functionalized sulphamethoxazoles

NASA Astrophysics Data System (ADS)

Sahu, Nilima; Mondal, Sudipa; Naskar, Kaushik; Mahapatra, Ananya Das; Gupta, Suvroma; Slawin, Alexandra M. Z.; Chattopadhyay, Debprasad; Sinha, Chittaranjan

2018-03-01

[SMXsbnd Ndbnd Nsbnd C6H3sbnd (p-OH)(msbnd CHO)] (1) reacts with ArNH2 to synthesize Schiff bases, [SMXsbnd Ndbnd Nsbnd C6H3sbnd (psbnd OH)(msbnd HCdbnd Nsbnd Ar)] (Ar = sbnd C6H5 (2a), sbnd C6H4sbnd psbnd CH3 (2b), sbnd C6H4sbnd psbnd OCH3 (2c), sbnd C6H4sbnd psbnd Cl (2d), sbnd C6H4sbnd psbnd NO2 (2e), sbnd C10H7 (2f)) and the products have been assessed for antibacterial properties against Gram positive bacteria, B. subtillis: IC50 (μg/ml): 39.2 (1), 60.1 (2a), 64.0 (2b), 85.6 (2c), 55.1 (2d), 88.4 (2e) and 65.1 (2f); and Gram negative bacteria, E. coli: IC50 (μg/ml): 159.0 (1), 151.4 (2a), 155.3 (2b), 140 (2c), 156.0 (2d), 153.5 (2e) and 157 (2f). The cell line toxicity (Vero cells) has also been evaluated with these compounds and EC50 (μg/ml) values are 129.9 (1), 74.2 (2a) and 93.0 (2b), 191.9 (2c), 99.1 (2d), 93.2 (2e) and 62.0 (2f). The anti-viral efficiency against harpies virus (HSVsbnd 1F ATCC-733) infection demonstrates that the compound 1 has highest selectivity index (CC50/EC50), 5.06 than the compounds 2a-f (CC50/EC50: 1.18 (2a), 1.42 (2b), 3.50 (2c), 1.45 (2d), 1.58 (2e), 1.29 (2f)). The compounds have been spectroscopically characterized and the structural confirmation has been established in one case by single crystal X-ray diffraction studies of 2c. In silico Molecular Docking study has been done using optimized geometries of the compounds to search the most favored binding mode of these drugs and hence useful to explain their competitive drug efficiency.

Antimicrobial constituents of peel and seeds of camu-camu (Myrciaria dubia).

PubMed

Kaneshima, Tai; Myoda, Takao; Toeda, Kazuki; Fujimori, Takane; Nishizawa, Makoto

2017-08-01

Various antimicrobial constituents of camu-camu fruit were isolated. Acylphloroglucinol (compound 1) and rhodomyrtone (compound 2) were isolated from the peel of camu-camu (Myrciaria dubia) fruit, while two other acylphloroglucinols (compounds 3 and 4) were obtained from camu-camu seeds. The structures of the isolated compounds were characterized by spectrophotometric methods. Compounds 1 and 4 were confirmed to be new acylphloroglucinols with different substituents at the C7 or C9 position of 2, and were named myrciarone A and B, respectively. Compound 3 was determined to be isomyrtucommulone B. This is the first report of the isolation of 3 from a natural resource. The antimicrobial activities of compounds 1, 3, and 4 were similar to those of 2, and the minimum inhibitory concentrations were either similar to or lower than that of kanamycin. These results suggest that the peel and seeds of camu-camu fruit could be utilized for therapeutic applications.

AQUO-OXALATO-SULFATE COMPOUNDS OF URANIUM (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chernyaev, I.I.; Golovnya, V.A.; Shchelokov, R.N.

1960-07-01

The following mixed aquo-acido complex uranyl compounds containing an oxalate and a sulfate group were synthesized for the first time: K/sub 2/STAUO/ sub 2/(C/sub 2/O/sub 4/) (SO/sub 4/ (H/sub 2/O)/sub 2/!. H/sub 2/O, Rb/sub 2/ STAUO/sub 2/(C/sub 2/O/sub 4/)(SO/sub 4/)(H/sub 2/O)/sub 2/!, Cs/sub 2/STAUO/sub 2/(C/sub 2/O/sub 4/)(SO/sub 4/)(H/sub 2/O)/sub 2/)!, and Cs(NH/sub 4/) (UO/sub 2/ (C/sub 2/O/sub 4/) (SO/sub 4/)(H/sub 2/O)/sub 2/!. T he molecular conductivity and pH were determined in dilute solutions, and it was concluded that the decrease in stability of these complexes in aqueous solution is as follows: STAUO/ sub 2/(C/sub 2/O/sub 4/)/sub 2/(H/sub 2/O)/sub 2/!/sup 2-/more » > STAUO/sub 2/(C/su b 2/O/sub 4/)(SO/sub 4)(H/sub 2/O)/sub 2/!/sup 2-/ > STAUO/sub 2/(SO/sub 4/)/sub 2/ (H/sub 2O)/sub 2/!/sup 2-. (TTT)« less

Synthesis, Anti-inflammatory and Antibacterial Activities of Novel Pyrazolo[4,3-g]pteridines.

PubMed

Abdel-Mohsen, Shawkat Ahmed; El-Emary, Talaat Ibrahim; El-Kashef, Hussein Salama

2016-01-01

A novel series of 6-substituted pyrazolo[3,4-g]pteridines 2-9 and pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pteridin-2(3H)-one (thione) 10 and 11 was synthesized using the starting compound 3,7-dimethyl-1-phenylpyrazolo[4',3':5,6]pyrazino[2,3-d][1,3]oxazin-5(1H)-one 2. The structure of the newly synthesized compounds was elucidated by IR, (1)H-NMR, (13)C-NMR, mass spectroscopy and elemental analyses. The anti-inflammatory activity of all the newly synthesized compounds was evaluated using the carrageenan-induced paw oedema test in rats using indomethacin as the reference drug. Compound 11 and the two derivatives 7f and 8b were the most active compounds, showing an activity comparable to indomethacin. Also, the synthesized compounds were evaluated for their antibacterial activity against Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) using chloramphenicol as control. The pyrazolotriazolopteridin-2-thione 11, 6-hydroxyethyl- 6a, 6-(4-nitrophenyl)-7g, and 6-(phenylamino) 8b derivatives were found to be the most active compounds against the Gram-positive species. None of them showed any activity against Gram-negative species.

Preparation, Characterization, and Structure of Two Layered Molybdenum(VI) Phosphates: KMo(H 2O)O 2PO 4 and NH 4Mo(H 2O)O 2PO 4

NASA Astrophysics Data System (ADS)

Millini, Roberto; Carati, Angela

1995-08-01

New layered Mo(VI) compounds, KMo(H 2O)O 2PO 4 (I) and NH 4Mo(H 2O)O 2PO 4 (II), were synthesized hydrothermally and their structures were determined from single-crystal X-ray analysis. Compounds (I) and (II) are isostructural and crystallize in the monoclinic P2 1/ n space group with a = 12.353(3), b = 8.623(2), c = 5.841(1) Å, β = 102.78(1)°, V = 606.8(2) Å 3, Z = 4, and R = 0.027 ( Rw = 0.030) for compound (I) and a = 12.435(3), b = 8.761(2), c = 6.015(1), β = 103.45(1)°, V = 637.3(2) Å 3, Z = 4, and R = 0.040 ( Rw = 0.041) for compound (II). The structure consists of layers built up of eight- and four-membered rings resulting from the alternation of corner-sharing [MoO 6] octahedra and [PO 4] tetrahedra. The layers stack along the (1¯01) direction by intercalating K and NH 4 ions.

Structural study of dehydration mechanisms of NH4Th(NO3)5·9H2O

NASA Astrophysics Data System (ADS)

Knyazev, A. V.; Komshina, M. E.; Baranov, E. V.; Savushkin, I. A.; Nipruk, O. V.; Lukoyanov, A. Yu.

2017-12-01

The new pentanitrate thorium compounds NH4Th(NO3)5·nH2O were synthesized and their crystal structures were determined by X-ray diffraction analysis: space group P21/n, a = 10.5476(5), b = 14.0444(7), c = 15.5287(8) Å, β = 109.4999(7)°, Z = 4; R = 0.0246 (NH4Th(NO3)5·9H2O); space group P212121, a = 8.7039(4), b = 11.9985(6), c = 16.3531(8) Å, Z = 4; R = 0.0259 (NH4Th(NO3)5·5H2O). Features of structural changes in the dehydration were revealed. Conditions of thermal decomposition of the thorium compound were established using differential scanning calorimetry. The compound was investigated by IR spectroscopy and its bands are assigned.

Two novel compounds from the root bark of Morus alba L.

PubMed

Li, Ming; Wu, Xuewei; Wang, Xiaoning; Shen, Tao; Ren, Dongmei

2018-01-01

Chemical investigation of the root bark of Morus alba led to the isolation of a new flavone, dioxycudraflavone A (1) and a new 2-arylbenzofuran, 5-hydroxyethyl moracin M (2), together with seven known compounds namely sanggenon V (3), morusin (4), morusignin L (5), licoflavone C (6), moracin C (7), alfafuran (8) and mulberrofuran G (9). The structure elucidation of these compounds was based on analyses of spectroscopic data including 1D, 2D NMR and HR-ESI-MS. All compounds were evaluated for the α-glucosidase inhibitory and cytotoxic activities. Compounds 2-4, 8 and 9 exhibited strong α-glucosidase inhibitory activities with IC 50 less than 10 μM, while only 4 and 9 showed moderate cytotoxic effects against lung cancer cells.

Formation and Ecotoxicity of N-Heterocyclic Compounds on Ammoxidation of Mono- and Polysaccharides

PubMed Central

2013-01-01

Ammoxidation of technical lignins under mild conditions is a suitable approach to artificial humic substances. However, carbohydrates as common minor constituents of technical lignins have been demonstrated to be a potential source of N-heterocyclic ecotoxic compounds. Ethyl acetate extracts of ammoxidation mixtures of the monosaccharides glucose and xylose exhibited considerable growth inhibiting activity in the OECD 201 test, with 4-methyl-1H-imidazole, 4-(hydroxymethyl)-1H-imidazole, and 3-hydroxypyridine being the most active compounds. The amount of N-heterocyclic compounds formed at moderate ammoxidation conditions (70 °C, 0.2 MPa O2, 3 h) was significantly lower for the polysaccharides cellulose and xylan (16–30 μg/g of educt) compared to glucose (15.4 mg). Ammoxidation at higher temperature is not recommendable for carbohydrate-rich materials as much higher amounts of N-heterocyclic compounds were formed from both monosaccharides (100 °C: 122.4–160.5 mg/g of educt) and polysaccharides (140 °C: 5.52–16.03 mg/g of educt). PMID:23967874

Crystal structure, quantum mechanical investigation, IR and NMR spectroscopy of two new organic perchlorates: (C6H18N3)·(ClO4)3H2O (I) and (C9H11N2)·ClO4(II)

NASA Astrophysics Data System (ADS)

Bayar, I.; Khedhiri, L.; Soudani, S.; Lefebvre, F.; Ferretti, V.; Ben Nasr, C.

2018-06-01

The reaction of perchloric acid with 1-(2-aminoethyl)piperazine or 5,6-dimethyl-benzimidazole results in the formation of 1-(2-amonioethyl)piperazine-1,4-dium triperchlorate hydrate (C6H18N3)·(ClO4)3·H2O (I) or 5,6-dimethyl-benzylimidazolium perchlorate (C9H11N2)·ClO4(II). Both compounds were fully structurally characterized including single crystal X-ray diffraction analysis. Compound (I) crystallizes in the centrosymmetric triclinic space group P 1 bar with the lattice parameters a = 7.455 (2), b = 10.462 (2), c = 10.824 (2) Å, α = 80.832 (2), β = 88.243 (2), γ = 88.160 (2) °, Z = 2 and V = 832.77 (3) Å3. Compound (II) has been found to belong to the P21/c space group of the monoclinic system, with a = 7.590 (3), b = 9.266 (3), c = 16.503 (6) Å, β = 107.38 (2) °, V = 1107.69 (7) Å3 and Z = 4. The structures of (I) and (II) consist of slightly distorted [ClO4]- tetrahedra anions and 1-(2-amonioethyl)piperazine-1,4-dium trication (I) or 5,6-dimethyl-benzylimidazolium cations (II) and additionally a lattice water in (I). The crystal structures of (I) and (II) exhibit complex three-dimensional networks of H-bonds connecting all their components. In the atomic arrangement of (I), the ClO4- anions form corrugated chains, while in (II) the atomic arrangement exhibits wide pseudo-hexagonal channels of ClO4 tetrahedra including the organic entities. The lattice water serves as a link between pairs of cations and pairs of anions via several Osbnd H⋯O and N-H⋯O interactions in compound (I). The vibrational absorption bands were identified by infrared spectroscopy. These compounds were also investigated by solid-state 13C, 35Cl and 15N NMR spectroscopy. DFT calculations allowed the attribution of the IR and NMR bands. Intermolecular interactions were investigated by Hirshfeld surfaces. Electronic properties such as HOMO and LUMO energies were derived.

Apoptosis mediated anti-proliferative effect of compound isolated from Cassia auriculata leaves against human colon cancer cell line

NASA Astrophysics Data System (ADS)

Esakkirajan, M.; Prabhu, N. M.; Manikandan, R.; Beulaja, M.; Prabhu, D.; Govindaraju, K.; Thiagarajan, R.; Arulvasu, C.; Dhanasekaran, G.; Dinesh, D.; Babu, G.

2014-06-01

A compound was isolated from Cassia auriculata leaves and characterized by high-performance liquid chromatography (HPLC), liquid chromatography mass spectrometry (LC-MS), UV-vis spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance spectroscopy (NMR). The in vitro anticancer effect of the compound isolated from C. auriculata was evaluated in human colon cancer cells HCT 15 by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cytotoxicity, nuclear morphology analysis and measurement of lactate dehydrogenase. The isolated compound 4-(2,5 dichlorobenzyl)-2,3,4,5,6,7 hexahydro7(4 methoxyphenyl)benzo[h][1,4,7] triazecin8(1H)-one showed 50% inhibition of HCT 15 cells when tested at 20 μg/ml after 24 h incubation. Cytotoxicity, nuclear morphology and lactate dehydrogenase assays clearly show potent anticancer activity of the isolated compound against colon cancer. Thus, the in vitro findings suggest that the compound isolated from C. auriculata leaves have potent anti-cancer properties with possible clinical applications.

Synthesis, characterization stereochemistry and anti-bacterial evaluation of certain N-acyl-c-3,t-3-dimethyl-r-2,c-6-diphenylpiperidin-4-ones

NASA Astrophysics Data System (ADS)

Ponnuswamy, S.; Kayalvizhi, R.; Jamesh, M.; Uma Maheswari, J.; Thenmozhi, M.; Ponnuswamy, M. N.

2016-09-01

A new series of N-acyl-c-3,t-3-dimethyl-r-2,c-6-diphenylpiperidin-4-ones 2-6 has been synthesized and characterized using IR, mass, 1H, 13C, DEPT and 2D (COSY and HSQC) NMR spectral techniques. The NMR spectral data indicate that the N-acylpiperidin-4-ones 2-6 prefer to exist in a distorted boat conformation B1 with coplanar orientation of N-C=O moiety. The stereodynamics of these systems have been studied by recording the dynamic 1H NMR spectra of compound 4, and the energy barrier for N-CO rotation is determined to be 52.75 kJ/mol. Furthermore the compounds 1-5 show significant antibacterial activity.

Substituent effects in a series of 1,7-C[subscript 60](R[subscript F])[subscript 2] compounds (R[subscript F] = CF[subscript 3], C[subscript 2]F[subscript 5], n-C[subscrip 3]F[subscript 7], i-C[subscript 3]F[subscript 7], n-C[subscript 4]F[subscript 9], s-C[subscript 4]F[subscript 9], n-C[subscript 8]F[subscript 17]): electron affinities, reduction potentials and E(LUMO) values are not always correlated

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuvychko, Igor V.; Whitaker, James B.; Larson, Bryon W.

2013-04-08

A series of seven structurally-similar compounds with different pairs of R{sub F} groups were prepared, characterized spectroscopically, and studied by electrochemical methods (cyclic and square-wave voltammetry), low-temperature anion photoelectron spectroscopy, and DFT calculations (five of the compounds are reported here for the first time). This is the first time that a set of seven R{sub F} groups have been compared with respect to their relative effects on E{sub 1/2}(0/-), electron affinity (EA), and the DFT-calculated LUMO energy. The compounds, 1,7-C{sub 60}(R{sub F}){sub 2} (R{sub F} = CF{sub 3}, C{sub 2}F{sub 5}, i-C{sub 3}F{sub 7}, n-C{sub 3}F{sub 7}, s-C{sub 4}F{sub 9},more » n-C{sub 4}F{sub 9} and n-C{sub 8}F{sub 21}), were found to have statistically different electron affinities (EA), at the {+-}10 meV level of uncertainty, but virtually identical first reduction potentials, at the {+-}10 mV level of uncertainty. The lack of a correlation between EA and E{sub 1/2}(0/-), and between E(LUMO) and E{sub 1/2}(0/-), for such similar compounds is unprecedented and suggests that explanations for differences in figures of merit for materials and/or devices that are based on equating easily measurable E{sub 1/2}(0/-) values with EAs or E(LUMO) values should be viewed with caution. The solubilities of the seven compounds in toluene varied by nearly a factor of six, but in an unpredictable way, with the C{sub 2}F{sub 5} and s-C{sub 4}F{sub 9} compounds being the most soluble and the i-C{sub 3}F{sub 7} compound being the least soluble. The effects of the different R{sub F} groups on EAs, E(LUMO) values, and solubilities should help fluorine chemists choose the right R{sub F} group to design new materials with improved morphological, electronic, optical, and/or magnetic properties.« less

Reactivity of cyclopentadienyl transition metal(ii) complexes with borate ligands: structural characterization of the toluene-activated molybdenum complex [Cp*Mo(CO)2(η3-CH2C6H5)].

PubMed

Ramalakshmi, Rongala; Maheswari, K; Sharmila, Dudekula; Paul, Anamika; Roisnel, Thierry; Halet, Jean-François; Ghosh, Sundargopal

2016-10-18

Reactions of cyclopentadienyl transition-metal halide complexes [Cp*Mo(CO) 3 Cl], 1, and [CpFe(CO) 2 I], 2, (Cp = C 5 H 5 ; Cp* = η 5 -C 5 Me 5 ) with borate ligands are reported. Treatment of 1 with [NaBt 2 ] (Bt 2 = dihydrobis(2-mercapto-benzothiazolyl)borate) in toluene yielded [Cp*Mo(CO) 2 (C 7 H 4 S 2 N)], 3, and [Cp*Mo(CO) 2 (η 3 -CH 2 C 6 H 5 )], 4, with a selective binding of toluene through C-H activation followed by orthometallation. Note that compound 4 is a structurally characterized toluene-activated molecule in which the metal is in η 3 -coordination mode. Under similar reaction conditions, [NaPy 2 ] (Py 2 = dihydrobis(2-mercaptopyridyl)borate) produced only the mercaptopyridyl molybdenum complex [Cp*Mo(CO) 2 (C 5 H 4 SN)], 5, in good yield. On the other hand, when compound 2 was treated individually with [NaBt] (Bt = trihydro(2-mercapto-benzothiazolyl)borate) and [NaPy 2 ] in THF, formation of the η 1 -coordinated complexes [CpFe(CO) 2 (C 7 H 4 S 2 N)], 6, and [CpFe(CO) 2 (C 5 H 4 SN)], 7, was observed. The solid-state molecular structures of compounds 3, 4, 6, and 7 have been established by single-crystal X-ray crystallographic analyses.

Identification and hit-to-lead optimization of a novel class of CB1 antagonists.

PubMed

Letourneau, Jeffrey J; Jokiel, Patrick; Olson, John; Riviello, Christopher M; Ho, Koc-Kan; McAleer, Lihong; Yang, Jingchun; Swanson, Robert N; Baker, James; Cowley, Phillip; Edwards, Darren; Ward, Nick; Ohlmeyer, Michael H J; Webb, Maria L

2010-09-15

The discovery, synthesis and preliminary structure-activity relationships (SARs) of a novel class of CB1 antagonists is described. Initial optimization of benzimidazole-based screening hit 4 led to the identification of 'inverted' indole-based lead compound 18c with improved properties versus compound 4 including reduced AlogP, improved microsomal stability and improved aqueous solubility. Compound 18c demonstrates in vivo CB1 antagonist efficacy (CB1 agonist induced hypothermia model) and is orally bioavailable in rat. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Characterization of Imidazopyridine Compounds as Negative Allosteric Modulators of Proton-Sensing GPR4 in Extracellular Acidification-Induced Responses

PubMed Central

Tobo, Ayaka; Tobo, Masayuki; Nakakura, Takashi; Ebara, Masashi; Tomura, Hideaki; Mogi, Chihiro; Im, Dong-Soon; Murata, Naoya; Kuwabara, Atsushi; Ito, Saki; Fukuda, Hayato; Arisawa, Mitsuhiro; Shuto, Satoshi; Nakaya, Michio; Kurose, Hitoshi; Sato, Koichi; Okajima, Fumikazu

2015-01-01

G protein-coupled receptor 4 (GPR4), previously proposed as the receptor for sphingosylphosphorylcholine, has recently been identified as the proton-sensing G protein-coupled receptor (GPCR) coupling to multiple intracellular signaling pathways, including the Gs protein/cAMP and G13 protein/Rho. In the present study, we characterized some imidazopyridine compounds as GPR4 modulators that modify GPR4 receptor function. In the cells that express proton-sensing GPCRs, including GPR4, OGR1, TDAG8, and G2A, extracellular acidification stimulates serum responsive element (SRE)-driven transcriptional activity, which has been shown to reflect Rho activity, with different proton sensitivities. Imidazopyridine compounds inhibited the moderately acidic pH-induced SRE activity only in GPR4-expressing cells. Acidic pH-stimulated cAMP accumulation, mRNA expression of inflammatory genes, and GPR4 internalization within GPR4-expressing cells were all inhibited by the GPR4 modulator. We further compared the inhibition property of the imidazopyridine compound with psychosine, which has been shown to selectively inhibit actions induced by proton-sensing GPCRs, including GPR4. In the GPR4 mutant, in which certain histidine residues were mutated to phenylalanine, proton sensitivity was significantly shifted to the right, and psychosine failed to further inhibit acidic pH-induced SRE activation. On the other hand, the imidazopyridine compound almost completely inhibited acidic pH-induced action in mutant GPR4. We conclude that some imidazopyridine compounds show specificity to GPR4 as negative allosteric modulators with a different action mode from psychosine, an antagonist susceptible to histidine residues, and are useful for characterizing GPR4-mediated acidic pH-induced biological actions. PMID:26070068

Characterization of Imidazopyridine Compounds as Negative Allosteric Modulators of Proton-Sensing GPR4 in Extracellular Acidification-Induced Responses.

PubMed

Tobo, Ayaka; Tobo, Masayuki; Nakakura, Takashi; Ebara, Masashi; Tomura, Hideaki; Mogi, Chihiro; Im, Dong-Soon; Murata, Naoya; Kuwabara, Atsushi; Ito, Saki; Fukuda, Hayato; Arisawa, Mitsuhiro; Shuto, Satoshi; Nakaya, Michio; Kurose, Hitoshi; Sato, Koichi; Okajima, Fumikazu

2015-01-01

G protein-coupled receptor 4 (GPR4), previously proposed as the receptor for sphingosylphosphorylcholine, has recently been identified as the proton-sensing G protein-coupled receptor (GPCR) coupling to multiple intracellular signaling pathways, including the Gs protein/cAMP and G13 protein/Rho. In the present study, we characterized some imidazopyridine compounds as GPR4 modulators that modify GPR4 receptor function. In the cells that express proton-sensing GPCRs, including GPR4, OGR1, TDAG8, and G2A, extracellular acidification stimulates serum responsive element (SRE)-driven transcriptional activity, which has been shown to reflect Rho activity, with different proton sensitivities. Imidazopyridine compounds inhibited the moderately acidic pH-induced SRE activity only in GPR4-expressing cells. Acidic pH-stimulated cAMP accumulation, mRNA expression of inflammatory genes, and GPR4 internalization within GPR4-expressing cells were all inhibited by the GPR4 modulator. We further compared the inhibition property of the imidazopyridine compound with psychosine, which has been shown to selectively inhibit actions induced by proton-sensing GPCRs, including GPR4. In the GPR4 mutant, in which certain histidine residues were mutated to phenylalanine, proton sensitivity was significantly shifted to the right, and psychosine failed to further inhibit acidic pH-induced SRE activation. On the other hand, the imidazopyridine compound almost completely inhibited acidic pH-induced action in mutant GPR4. We conclude that some imidazopyridine compounds show specificity to GPR4 as negative allosteric modulators with a different action mode from psychosine, an antagonist susceptible to histidine residues, and are useful for characterizing GPR4-mediated acidic pH-induced biological actions.

Chalcone-based Selective Inhibitors of a C4 Plant Key Enzyme as Novel Potential Herbicides

NASA Astrophysics Data System (ADS)

Nguyen, G. T. T.; Erlenkamp, G.; Jäck, O.; Küberl, A.; Bott, M.; Fiorani, F.; Gohlke, H.; Groth, G.

2016-06-01

Weeds are a challenge for global food production due to their rapidly evolving resistance against herbicides. We have identified chalcones as selective inhibitors of phosphoenolpyruvate carboxylase (PEPC), a key enzyme for carbon fixation and biomass increase in the C4 photosynthetic pathway of many of the world’s most damaging weeds. In contrast, many of the most important crop plants use C3 photosynthesis. Here, we show that 2‧,3‧,4‧,3,4-Pentahydroxychalcone (IC50 = 600 nM) and 2‧,3‧,4‧-Trihydroxychalcone (IC50 = 4.2 μM) are potent inhibitors of C4 PEPC but do not affect C3 PEPC at a same concentration range (selectivity factor: 15-45). Binding and modeling studies indicate that the active compounds bind at the same site as malate/aspartate, the natural feedback inhibitors of the C4 pathway. At the whole plant level, both substances showed pronounced growth-inhibitory effects on the C4 weed Amaranthus retroflexus, while there were no measurable effects on oilseed rape, a C3 plant. Growth of selected soil bacteria was not affected by these substances. Our chalcone compounds are the most potent and selective C4 PEPC inhibitors known to date. They offer a novel approach to combat C4 weeds based on a hitherto unexplored mode of allosteric inhibition of a C4 plant key enzyme.

Chalcone-based Selective Inhibitors of a C4 Plant Key Enzyme as Novel Potential Herbicides

PubMed Central

Nguyen, G. T. T.; Erlenkamp, G.; Jäck, O.; Küberl, A.; Bott, M.; Fiorani, F.; Gohlke, H.; Groth, G.

2016-01-01

Weeds are a challenge for global food production due to their rapidly evolving resistance against herbicides. We have identified chalcones as selective inhibitors of phosphoenolpyruvate carboxylase (PEPC), a key enzyme for carbon fixation and biomass increase in the C4 photosynthetic pathway of many of the world’s most damaging weeds. In contrast, many of the most important crop plants use C3 photosynthesis. Here, we show that 2′,3′,4′,3,4-Pentahydroxychalcone (IC50 = 600 nM) and 2′,3′,4′-Trihydroxychalcone (IC50 = 4.2 μM) are potent inhibitors of C4 PEPC but do not affect C3 PEPC at a same concentration range (selectivity factor: 15–45). Binding and modeling studies indicate that the active compounds bind at the same site as malate/aspartate, the natural feedback inhibitors of the C4 pathway. At the whole plant level, both substances showed pronounced growth-inhibitory effects on the C4 weed Amaranthus retroflexus, while there were no measurable effects on oilseed rape, a C3 plant. Growth of selected soil bacteria was not affected by these substances. Our chalcone compounds are the most potent and selective C4 PEPC inhibitors known to date. They offer a novel approach to combat C4 weeds based on a hitherto unexplored mode of allosteric inhibition of a C4 plant key enzyme. PMID:27263468

Syntheses, Structural Characterization and Thermoanalysis of Transition-Metal Compounds Derived from 3,5-Dinitropyridone.

PubMed

Fan, Rong; Zhou, Qiu-Ping; Zhang, Guo-Fang; Cai, Mei-Yu; Li, Ping; Gan, Li-Hua; Zhao, Feng-Qi; Li, Ji-Zhen; Fan, Xue-Zhong; Ng, Seik Weng

2009-09-28

Nine metal compounds of Mn(II), Zn(II) and Cd(II) derived from dinitropyridone ligands (3,5-dinitro-pyrid-2-one, 2HDNP; 3,5-dinitropyrid-4-one, 4HDNP and 3,5-dinitropyrid-4-one-N- hydroxide, 4HDNPO) were characterized by elemental analysis, FT-IR and partly by TG-DSC. Three of which were further structurally characterized by X-ray single-crystal diffraction analysis. The structures of the three compounds, Mn(4DNP)(2)(H(2)O)(4), 4, Zn(4DNPO)(2)(H(2)O)(4), 8, and Cd(4DNPO)(2)(H(2)O)(4), 9, crystallize in the monoclinic space group P2(1)/n and Z = 2, with a = 8.9281(9), b = 9.1053(9), c = 10.6881(11) A, beta = 97.9840(10) degrees for 4; a = 8.4154(7), b = 9.9806(8), c = 10.5695(8) A, beta = 97.3500(10) degrees for 8; a = 8.5072(7), b = 10.2254(8), c = 10.5075(8) A, beta 96.6500(10) degrees for 9. All three complexes are octahedral consisting of four equatorial water molecules, and two nitrogen or oxygen donor ligands (DNP or DNPO). The abundant hydrogen-bonding and pi-pi stacking interactions seem to contribute to stabilization of the crystal structures of the compounds. The TG-DTG results revealed that the complexes showed a weight loss sequence corresponding to all coordinated water molecules, nitro groups, the breaking of the pyridine rings and finally the formation of metal oxides.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Chen; Pinkerton, Frederick E.; Herbst, Jan F.

New magnetic materials containing cerium, iron, and small additions of a third element are disclosed. These materials comprise compounds Ce(Fe.sub.12-xM.sub.x) where x=1-4, having the ThMn.sub.12 tetragonal crystal structure (space group I4/mmm, #139). Compounds with M=B, Al, Si, P, S, Sc, Co, Ni, Zn, Ga, Ge, Zr, Nb, Hf, Ta, and W are identified theoretically, and one class of compounds based on M=Si has been synthesized. The Si cognates are characterized by large magnetic moments (4.pi.M.sub.s greater than 1.27 Tesla) and high Curie temperatures (264.ltoreq.T.sub.c.ltoreq.305.degree. C.). The Ce(Fe.sub.12-xM.sub.x) compound may contain one or more of Ti, V, Cr, and Mo inmore » combination with an M element. Further enhancement in T.sub.c is obtained by nitriding the Ce compounds through heat treatment in N.sub.2 gas while retaining the ThMn.sub.12 tetragonal crystal structure; for example CeFe.sub.10Si.sub.2N.sub.1.29 has T.sub.c=426.degree. C.« less

Preparation of 3,3'-azobis(6-amino-1,2,4,5-tetrazine)

DOEpatents

Hiskey, Michael A.; Chavez, David E.; Naud, Darren

2002-01-01

The compound of the structure ##STR1## where a, b, c, d and e are 0 or 1 and a+b+c+d+e is from 0 to 5 is disclosed together with the species 3,3'-azobis(6-amino-1,2,4,5-tetrazine) and a process of preparing such compounds.

Structural and fluorescence properties of the 2,2‧-methylenediphenoxy and 1,1‧-methylenedi-2-naphthoxy cyclotriphosphazene derivatives

NASA Astrophysics Data System (ADS)

Yenilmez Çiftçi, Gönül; Eker, Yakup; Şenkuytu, Elif; Yuksel, Fatma

2016-08-01

In the present work, the partially or fully substituted spiro-, ansa, open-chain forms of 2,2'-methylenediphenoxy, 1,1'-methylenedi-2-naphthoxy cyclotriphosphazene derivatives and their spectral properties were reported. The reactions of hexachlorocyclotriphosphazene [trimer, N3P3Cl6, (1)] with 2,2'-methylenediphenol (2) and 1,1'-methylenedi-2-naphthol (3) in THF produced new cyclotriphosphazene compounds (4-11). All these compounds (4-11) were fully characterized by elemental analysis, FT-IR, MALDI-TOF mass spectrometry, UV Vis, 1H, 13C and 31P NMR spectroscopy. The molecular structures of 4, 5, 7, 9 and 10 were also determined by X-ray crystallography. All five structures were found in monoclinic system, C2/c, P21/n or P21/c space groups. The fluorescence behaviour of the studied cyclotriphosphazene derivatives (9-11) were also examined in THF solution. Compound 11 showed the highest fluorescence emission behaviour that of compounds 4-10.

A Role for 2-Methyl Pyrrole in the Browning of 4-Oxopentanal and Limonene Secondary Organic Aerosol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aiona, Paige K.; Lee, Hyun Ji; Lin, Peng

“Brown Carbon” (BrC) is a type of organic particulate matter that absorbs visible and near ultraviolet radiation. Reactions of carbonyls in secondary organic aerosol (SOA) produced from limonene with ammonia (NH3) or ammonium sulfate (AS) are known to produce BrC with a distinctive absorption band at 500 nm. Although the general mechanism for this process has been proposed in previous studies, the specific molecular structures of the light-absorbing species remain unclear. This study examined the browning processes occurring in aqueous solutions of AS and 4-oxopentanal (4-OPA), which has a 1,4-dicarbonyl structural motif present in many limonene SOA compounds. The reactionmore » of 4-OPA with AS in a bulk aqueous solution produces a 2-methyl pyrrole (2-MP) intermediate, which is not a strong light absorber by itself, but can react further with carbonyl compounds leading to the eventual formation of BrC chromophores. The direct involvement of 2-MP in the browning process was demonstrated by reacting 2-MP with 4-OPA and with limonene SOA, both of which produced BrC chromophores with distinctive absorption bands at visible wavelengths. The formation of BrC in reaction of 4-OPA with AS and ammonium nitrate (AN) was found to be accelerated by evaporation of the solution suggesting an important role of the dehydration processes in BrC formation from 1,4- dicarbonyls. 4-OPA was also found to produce BrC in aqueous reactions with a broad spectrum of amino acids and amines. The results suggest that 4-OPA may be the smallest atmospherically relevant compound capable of browning by the same mechanism as limonene SOA.« less

New analogues of brefeldin A from sediment-derived fungus Penicillium sp. DT-F29.

PubMed

Hu, Zhi-Fei; Qin, Le-Le; Ding, Wan-Jing; Liu, Yu; Ma, Zhong-Jun

2016-10-01

Four new analogues of brefeldin A named 7, 7-dimethoxybrefeldin C (3), 6β-hydroxybrefeldin C (4), 4-epi-15-epi-brefeldin A (5), 4-epi-8α-hydroxy-15-epi-brefeldin C (6), together with four known analogues (1, 7-9) were isolated from a fermentation of the sediment-derived fungus Penicillium sp. DT-F29. The structures of these compounds were elucidated on the basis of extensive spectroscopic and chemical methods. In the bioactivity assays, only compounds 1 and 8 showed significant inhibitory activities against human lung adenocarcinoma cell. In addition, compound 1 was first reported for the potent ability to reactivate latent HIV with EC50 value of 0.03 μM.

Preparation and isolation of dithiolene thiophosphoryl molecules as stable, protected forms of dithiolene ligands.

PubMed

Arumugam, Kuppuswamy; Bollinger, James E; Fink, Mark; Donahue, James P

2007-04-16

The reaction of P4S10 with acyloins, RC(O)CH(OH)R, in refluxing dioxane, followed by the addition of alkylating agents, forms dithiolene thiophosphoryl thiolate compounds, (R2C2S2)P(S)(SR'), which are readily isolated and purified. The compounds that have been prepared and identified spectroscopically are those with R = p-anisyl, R' = Me (1); R = p-anisyl, R' = Bz (2); R = Ph, R' = Me (4); R = Et, R' = Bz (5). Compounds 1, 2, and 4 were structurally characterized by X-ray crystallography and found to possess a tetrahedral coordination geometry about the phosphorus atom, with overall Cs symmetry. In each case, the mirror plane bisects the dithiolene S-P-S chelate and contains the thiophosphoryl bond, which ranges in length from 1.9241(8) to 1.9361(7) A. The use of 2-(bromomethyl)naphthalene as organic electrophile in the P4S10/acyloin reaction produced bis(2-methylnaphthalenyl) disulfide as the only identifiable product. The substitution of Lawesson's reagent for P4S10 in reactions with acyloins produced deoxy acyloin rather than products resulting from chalcogen exchange. Compounds 1-2 and 4-5 are Group 5 analogues of 1,3-dithiol-2-ones, (R2C2S2)C=O, and undergo a similar hydrolysis in aqueous base to liberate ene-1,2-dithiolate dianions from which corresponding metal dithiolene complexes may be prepared. Deprotection of 1 in MeO-/MeOH, followed by the addition of NiCl2.6H2O and then I2, produces square planar [Ni(S2C2(C6H4-p-OCH3)2)2] (8) in 93% yield. A high-resolution structure of 8 (P) reveals dithiolene C-C and C-S bond lengths that are clearly indicative of the thionyl radical monoanionic nature of the ligand. The use of isolated (R2C2S2)P(S)(SR') compounds as a dithiolene ligand source for the preparation of metal dithiolene complexes offers the advantages of clean reactivity and high yield.

Design, Synthesis and Evaluation of Novel Phthalimide Derivatives as in Vitro Anti-Microbial, Anti-Oxidant and Anti-Inflammatory Agents.

PubMed

Lamie, Phoebe F; Phillopes, John N; El-Gendy, Ahmed O; Rarova, Lucie; Gruz, Jiri

2015-09-14

Sixteen new phthalimide derivatives were synthesized and evaluated for their in vitro anti-microbial, anti-oxidant and anti-inflammatory activities. The cytotoxicity for all synthesized compounds was also determined in cancer cell lines and in normal human cells. None of the target derivatives had any cytotoxic activity. (ZE)-2-[4-(1-Hydrazono-ethyl) phenyl]isoindoline-1,3-dione (12) showed remarkable anti-microbial activity. Its activity against Bacillus subtilis was 133%, 106% and 88.8% when compared with the standard antibiotics ampicillin, cefotaxime and gentamicin, respectively. Compound 12 also showed its highest activities in Gram negative bacteria against Pseudomonas aeruginosa where the percentage activities were 75% and 57.6% when compared sequentially with the standard antibiotics cefotaxime and gentamicin. It was also found that the compounds 2-[4-(4-ethyl-3-methyl-5-thioxo-1,2,4-triazolidin-3-yl)phenyl]isoindoline-1,3-dione (13b) and 2-[4-(3-methyl-5-thioxo-4-phenyl-1,2,4-triazolidin-3-yl)phenyl]isoindoline-1,3-dione (13c) had anti-oxidant activity. 4-(N'-{1-[4-(1,3-Dioxo-1,3-dihydro-isoindol-2-yl)-phenyl]-ethylidene}-hydrazino)-benzenesulfonamide (17c) showed the highest in vitro anti-inflammatory activity of the tested compounds (a decrease of 32%). To determine the mechanism of the anti-inflammatory activity of 17c, a docking study was carried out on the COX-2 enzyme. The results confirmed that 17c had a higher binding energy score (-17.89 kcal/mol) than that of the ligand celecoxib (-17.27 kcal/mol).

Three-component, one-pot synthesis of anthranilamide Schiff bases bearing 4-aminoquinoline moiety as Mycobacterium tuberculosis gyrase inhibitors.

PubMed

Salve, Preeti S; Alegaon, Shankar G; Sriram, Dharmarajan

2017-04-15

An efficient three-component, one-pot protocol is described for the synthesis of biologically interesting 2-(benzylideneamino)-N-(7-chloroquinolin-4-yl)benzohydrazide derivatives from isatoic anhydride, 7-chloro-4-hydrazinylquinoline and aromatic and/or hetero aromatic aldehydes under catalyst free condensation by using water as reaction media. All synthesized compounds were evaluated for their antimycobacterial activity against Mycobacterium tuberculosis (MTB) and cytotoxicity activity against normal VERO cell lines. The synthesized compounds exhibited minimum inhibitory concentration (MIC) ranging from 0.78 to 25μM. Among the tested compounds 4c, 4o, 4r, and 4u exhibited promising inhibitory activity (MIC=3.12μM). Compounds 4h and 4i stand out, showing MIC values of 0.78 and 1.56μM respectively. Both compounds were further screened for their Mycobacterium tuberculosis DNA gyrase inhibitory assay which suggested that these compounds have a great potential for further optimization and development as antitubercular agents. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis and Biological Screening of Pyrano[3,2-c]quinoline Analogues as Anti-inflammatory and Anticancer Agents.

PubMed

Upadhyay, Kuldip D; Dodia, Narsinh M; Khunt, Rupesh C; Chaniara, Ravi S; Shah, Anamik K

2018-03-08

A series of pyrano[3,2- c ]quinoline based structural analogues was synthesized using one-pot multicomponent condensation between 2,4-dihydroxy-1-methylquinoline, malononitrile, and diverse un(substituted) aromatic aldehydes. The synthesized compounds were evaluated for their anti-inflammatory and cytotoxicity activity. Initially, all the compounds were evaluated for the percent inhibition of cytokine release, and cytotoxicity activity and 50% inhibitory concentrations (IC 50 ) were also determined. Based on the primary results, it was further studied for their ability to inhibit TNF-α production in the human peripheral blood mononuclear cells (hPBMC) assay. The screening results revealed that compound 4c , 4f , 4i , and 4j were found most active candidates of the series against both anti-inflammatory and anticancer activity. The structure-activity relationship is discussed and suggested that 3-substitution on the aryl ring at C4 position of the pyrano[3,2- c ]quinolone structural motif seems to be an important position for both TNF-α and IL-6 inhibition and anticancer activity as well. However, structural diversity with electron withdrawing, electron donating, sterically hindered, and heteroaryl substitution sincerely affected both the inflammation and anticancer activities.

A new approach to construct a fused 2-ylidene chromene ring: highly regioselective synthesis of novel chromeno quinoxalines.

PubMed

Kumar, K Shiva; Rambabu, D; Prasad, Bagineni; Mujahid, Mohammad; Krishna, G Rama; Rao, M V Basaveswara; Reddy, C Malla; Vanaja, G R; Kalle, Arunasree M; Pal, Manojit

2012-06-28

Regioselective construction of a fused 2-ylidene chromene ring was achieved for the first time by using AlCl(3)-induced C-C bond formation followed by Pd/C-Cu mediate coupling-cyclization strategy. A number of chromeno[4,3-b]quinoxaline derivatives were prepared by using this strategy. Single crystal X-ray diffraction study of a representative compound e.g. 6-(2,2-dimethylpropylidene)-4-methyl-6H-chromeno[4,3-b]quinoxalin-3-ol confirmed the presence of an exocyclic C-C double bond with Z-geometry. The crystal structure analysis and hydrogen bonding patterns of the same compound along with its structure elaboration via propargylation followed by Sonogashira coupling of the resulting terminal alkyne is presented. A probable mechanism for the formation of 2-ylidene chromene ring is discussed. Some of the compounds synthesized showed anticancer properties when tested in vitro.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdelbaky, Mohammed S.M.; Amghouz, Zakariae; Department of Materials Science and Metallurgical Engineering, University of Oviedo, Campus Universitario, 33203 Gijón

Novel metal phosphonate [CuLi(PPA)] [H{sub 3}PPA=3-phosphonopropionic acid] was synthesized hydrothermally and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, scanning electron microscopy, infrared spectroscopy, and thermogravimetric analysis. It crystallizes in the space group C2/c, with cell parameters a=21.617(2) Å, b=4.9269(2) Å, c=14.342(1) Å, β=132.3(2)°, and Z=8. Its framework is built up from a main trimer, acting as a secondary building unit (SBU), which is formed by vertex-shared between two (LiO{sub 4}) and one (Cu(1)O{sub 4}) polyhedra. These units repeat along b-axis forming infinite inorganic chains, these chains are in turn cross-linked by corner sharing with (Cu(2)O{sub 4}) polyhedra to producemore » inorganic layers lying in the bc-plane. The neighboring layers are connected through the PPA ligand, leading to a 3D pillared-layered structure. The topological analysis reveals that the compound exhibits 3,4,10-c net. Finally, magnetic susceptibility measurement of this compound over the temperature range of 2–300 K reveals the occurrence of weak antiferromagnetic intrachain interactions. - Graphical abstract: Hydrothermal synthesis and structural characterization of a novel lithium-copper phosphonate, formulated as [CuLi(PPA)] (H{sub 3}PPA=3-phosphonopropionic acid), have been reported. This compound has a 3D pillared-layered structure with 3,4,10-c net topology. The magnetic susceptibility data over the temperature range of 2–300 K reveals the occurrence of weak antiferromagnetic interactions. - Highlights: • Novel metal phosphonate, [CuLi(PPA)] (1), has been synthesized and characterized. • Compound 1 has a 3D pillared-layered structure with 3,4,10-c net topology. • Magnetic susceptibility data reveals the occurrence of weak antiferromagnetic interactions.« less

One-atom-layer 4×4 compound in (Tl, Pb)/Si(111) system

NASA Astrophysics Data System (ADS)

Mihalyuk, A. N.; Hsing, C. R.; Wei, C. M.; Gruznev, D. V.; Bondarenko, L. V.; Tupchaya, A. Y.; Zotov, A. V.; Saranin, A. A.

2017-03-01

An ordered 4×4-periodicity 2D compound has been found in the (Tl, Pb)/Si(111) system and its composition, structure and electronic properties have been characterized using low-energy electron diffraction, scanning tunneling microscopy observations and density-functional-theory calculations. The compound has been concluded to contain 9 Tl atoms and 12 Pb atoms per 4×4 unit cell, i.e., 0.56 ML of Tl and 0.75 ML of Pb. Structural model was proposed for the 4×4-(Tl, Pb) compound where building blocks are a hexagonal array of 12 Pb atoms, a triangular array of 6 Tl atoms and a Tl trimer. The proposed structure has a C3 symmetry and occurs in the two equivalent orientations. The electron band structure of the compound contains two metallic spin-split surface-state bands. Bearing in mind the advanced properties of the known √{ 3 } ×√{ 3 } 2D compound in the same (Tl, Pb)/Si(111) system (i.e., combination of giant Rashba effect and superconductivity), the found 4×4-(Tl, Pb) compound is believed to be a promising object for exploration of its superconductive properties.

Synthesis, characterization, antimicrobial and enzymatic activity of 4b,9b-dihydroxy-7,8-dihydro-4bH-indeno[1,2-b]benzofuran-9,10(6H,9bH)-dione

NASA Astrophysics Data System (ADS)

Mehdi, Sayed Hasan; Hashim, Rokiah; Ghalib, Raza Murad; Fátima C. Guedes da Silva, M.; Sulaiman, Othman; Rahman, Syed Ziaur; Murugaiyah, Vikneswaran; Marimuthu, Mani Maran

2011-12-01

The crystal structure of the title compound, 4b,9b-dihydroxy-7,8-dihydro-4bH-indeno[1,2-b]benzofuran-9,10(6H,9bH)-dione has been determined by single crystal X-ray diffraction. It crystallizes in the monoclinic space group P2 1/c with Z = 4. The FTIR as well as the 1H and 13C NMR spectra of the compound were also recorded and briefly discussed. The compound showed potential antimicrobial activity comparable to that of clinically used antimicrobial agents against selected microorganisms. It has selective and moderate inhibitory activity on butyryl cholinesterase enzyme and could serve as potential lead compound for synthesis of more bioactive derivatives.

Antidermatophytic activity of pyrazolo[3,4-c]isothiazoles: a preliminary approach on 4-chlorophenyl derivative for evaluation of mutagenic and clastogenic effects on bacteria and human chromosomes in vitro.

PubMed

Rossi, Damiano; Mares, Donatella; Romagnoli, Carlo; Andreotti, Elisa; Manfredini, Stefano; Vicentini, Chiara Beatrice

2011-07-01

The antifungal activity of eight pyrazolo[3,4-c]isothiazole derivatives was evaluated on five dermatophytes: three were of an anthropophilic species (i.e., Epidermophyton floccosum, Trichophyton rubrum, and Trichophyton tonsurans) and two were of a geophilic species (i.e., Microsporum gypseum and Nannizzia cajetani). The new compounds proved to be unlikely effective in inhibiting the growth of the different strains. In general, the fungi parasitic on man were more sensitive than the geophilic species. This fact can be positive for a possible practical-therapeutic utilization of this class of compounds. To verify their possible use against fungi of medical interest, the most interesting substance at low doses, 6-(4-chlorophenyl)-4-methyl-6H-pyrazolo[3,4-c]isothiazol-3-amine, was chosen to perform in vitro genotoxicity tests using the following: Salmonella/microsome test (SAL), sister chromatid excange test (SCE), cytokinesis-blocked micronucleus test (CBMN), and its improvement (Ara-C/CBMN). The compound showed no mutagenic activity at low doses, whereas at the highest dose (100 µg/mL), it caused a generalized cytotoxic effect. The high growth inhibition exerted on fungi at the lowest dose and the concomitant lack of genotoxicity, at least until the dose of 50 µg/mL, might suggest the compound as a safe candidate as an antidermatophytic substance.

Syntheses, Structural Characterization and Thermoanalysis of Transition-Metal Compounds Derived from 3,5-Dinitropyridone

PubMed Central

Fan, Rong; Zhou, Qiu-Ping; Zhang, Guo-Fang; Cai, Mei-Yu; Li, Ping; Gan, Li-Hua; Zhao, Feng-Qi; Li, Ji-Zhen; Fan, Xue-Zhong; Ng, Seik Weng

2010-01-01

Nine metal compounds of Mn(II), Zn(II) and Cd(II) derived from dinitropyridone ligands (3,5-dinitro-pyrid-2-one, 2HDNP; 3,5-dinitropyrid-4-one, 4HDNP and 3,5-dinitropyrid-4-one-N- hydroxide, 4HDNPO) were characterized by elemental analysis, FT-IR and partly by TG-DSC. Three of which were further structurally characterized by X-ray single-crystal diffraction analysis. The structures of the three compounds, Mn(4DNP)2(H2O)4, 4, Zn(4DNPO)2(H2O)4, 8, and Cd(4DNPO)2(H2O)4, 9, crystallize in the monoclinic space group P2(1)/n and Z = 2, with a = 8.9281(9), b = 9.1053(9), c = 10.6881(11) Å, β = 97.9840(10)° for 4; a = 8.4154(7), b = 9.9806(8), c = 10.5695(8) Å, β = 97.3500(10)° for 8; a = 8.5072(7), b = 10.2254(8), c = 10.5075(8) Å, β 96.6500(10)° for 9. All three complexes are octahedral consisting of four equatorial water molecules, and two nitrogen or oxygen donor ligands (DNP or DNPO). The abundant hydrogen-bonding and π-π stacking interactions seem to contribute to stabilization of the crystal structures of the compounds. The TG-DTG results revealed that the complexes showed a weight loss sequence corresponding to all coordinated water molecules, nitro groups, the breaking of the pyridine rings and finally the formation of metal oxides. PMID:20526459

New vanadium tellurites: Syntheses, structures, optical properties of noncentrosymmetric VTeO{sub 4}(OH), centrosymmetric Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10})

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang, Ming-Li; State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002; Marsh, Matthew

Two new vanadium tellurites, VTeO{sub 4}(OH) (1) and Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10}) (2), have been synthesized successfully with the use of hydrothermal reactions. The crystal structures of the two compounds were determined by single-crystal X-ray diffraction. Compound 1 crystallizes in the polar space group Pca2{sub 1} (No. 29) while compound 2 crystallizes in the centrosymmetric space group C2/c (No. 15). The topography of compound 1 reveals a two-dimensional, layered structure comprised of VO{sub 6} octahedral chains and TeO{sub 3}(OH) zig-zag chains. Compound 2, on the contrary, features a three-dimensional [V{sub 4}O{sub 8}(Te{sub 3}O{sub 10})]{sup 4-} anionic framework withmore » Ba{sup 2+} ions filled into the 10-member ring helical tunnels. The [V{sub 4}O{sub 8}(Te{sub 3}O{sub 10})]{sup 4-} anionic network is the first 3D vanadium tellurite framework to be discovered in the alkaline-earth vanadium tellurite system. Powder second harmonic generation (SHG) measurements indicate that compound 1 shows a weak SHG response of about 0.3×KDP (KH{sub 2}PO{sub 4}) under 1064 nm laser radiation. Infrared spectroscopy, elemental analysis, thermal analysis, and dipole moment calculations have also been carried out. - Graphical abstract: VTeO{sub 4}(OH) (1) crystallizes in the noncentrosymmetric space group Pca2{sub 1} (No. 29) while Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10}) (2) crystallizes in the centrosymmetric space group C2/c (No. 15). - Highlights: • VTeO{sub 4}(OH) (1) and Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10}) (2) have been synthesized successfully with the use of hydrothermal reactions. • VTeO{sub 4}(OH) (1) crystallizes in the noncentrosymmetric space group Pca2{sub 1} and displays a weak SHG response. • VTeO{sub 4}(OH) (1) represents only the fourth SHG-active material found in vanadium tellurite systems. • Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10}) (2) exhibits a novel three-dimensional [V{sub 4}O{sub 8}(Te{sub 3}O{sub 10})]{sup 4-} anionic framework.« less

3,5-Dioxopyrazolidines, Novel Inhibitors of UDP-N- Acetylenolpyruvylglucosamine Reductase (MurB) with Activity against Gram-Positive Bacteria

PubMed Central

Yang, Youjun; Severin, Anatoly; Chopra, Rajiv; Krishnamurthy, Girija; Singh, Guy; Hu, William; Keeney, David; Svenson, Kristine; Petersen, Peter J.; Labthavikul, Pornpen; Shlaes, David M.; Rasmussen, Beth A.; Failli, Amedeo A.; Shumsky, Jay S.; Kutterer, Kristina M. K.; Gilbert, Adam; Mansour, Tarek S.

2006-01-01

A series of 3,5-dioxopyrazolidines was identified as novel inhibitors of UDP-N-acetylenolpyruvylglucosamine reductase (MurB). Compounds 1 to 3, which are 1,2-bis(4-chlorophenyl)-3,5-dioxopyrazolidine-4-carboxamides, inhibited Escherichia coli MurB, Staphyloccocus aureus MurB, and E. coli MurA with 50% inhibitory concentrations (IC50s) in the range of 4.1 to 6.8 μM, 4.3 to 10.3 μM, and 6.8 to 29.4 μM, respectively. Compound 4, a C-4-unsubstituted 1,2-bis(3,4-dichlorophenyl)-3,5-dioxopyrazolidine, showed moderate inhibitory activity against E. coli MurB, S. aureus MurB, and E. coli MurC (IC50s, 24.5 to 35 μM). A fluorescence-binding assay indicated tight binding of compound 3 with E. coli MurB, giving a dissociation constant of 260 nM. Structural characterization of E. coli MurB was undertaken, and the crystal structure of a complex with compound 4 was obtained at 2.4 Å resolution. The crystal structure indicated the binding of a compound at the active site of MurB and specific interactions with active-site residues and the bound flavin adenine dinucleotide cofactor. Peptidoglycan biosynthesis studies using a strain of Staphylococcus epidermidis revealed reduced peptidoglycan biosynthesis upon incubation with 3,5-dioxopyrazolidines, with IC50s of 0.39 to 11.1 μM. Antibacterial activity was observed for compounds 1 to 3 (MICs, 0.25 to 16 μg/ml) and 4 (MICs, 4 to 8 μg/ml) against gram-positive bacteria including methicillin-resistant S. aureus, vancomycin-resistant Enterococcus faecalis, and penicillin-resistant Streptococcus pneumoniae. PMID:16436710

Closer insight into the reactivity of TMP-dialkyl zincates in directed ortho-zincation of anisole: experimental evidence of amido basicity and structural elucidation of key reaction intermediates.

PubMed

Clegg, William; Conway, Ben; Hevia, Eva; McCall, Matthew D; Russo, Luca; Mulvey, Robert E

2009-02-18

The new dialkyl(aryl) lithium zincates [(THF)(2)Li(C(6)H(4)-OMe)MeZnMe] (4), [(TMEDA)Li(C(6)H(4)-OMe)MeZnMe] (6), [(THF)(3)Li(C(6)H(4)-OMe)(t)BuZn(t)Bu] (7), and [(PMDETA)Li(C(6)H(4)-OMe)(t)BuZn(t)Bu] (8) have been prepared by co-complexation reactions of lithiated anisole with the relevant dialkylzinc compound and the relevant Lewis base. These new heterobimetallic compounds have been characterized in solution using (1)H, (13)C{H}, and (7)Li NMR spectroscopy, and the molecular structures of 6 and 8 have been elucidated by X-ray crystallography. In 6 the distinct metals are connected through the anisole ligand which binds in an ambidentate fashion (through carbon-zinc and oxygen-lithium contacts) and also through one of the methyl groups, to close a [LiOCCZnC] six-membered ring; whereas 8 displays an open structure where anisole connects the two metals (in the same mode as in 6) but with the tert-butyl groups exclusively bonded terminally to zinc. Reactivity studies of zincates 4 and 7 with the amine TMP(H) supply experimental evidence that these heterobimetallic compounds are intermediates in the two-step deprotonation reaction of anisole by TMP-dialkyl zincates and show the relevance of the alkyl groups in the efficiency of TMP-dialkyl zincate bases. In addition, important solvent effects have also been evaluated. When hexane is added to THF solutions of compounds 4 or 7, the homoleptic tetraorganozincate [(THF)(2)Li(2)Zn(C(6)H(4)-OMe)(4)] (5) is obtained as the result of a disproportionation process. This lithium-rich zincate has also been spectroscopically and crystallographically characterized.

Synthesis, Structural Studies and Biological Evaluation of Connections of Thiosemicarbazide, 1,2,4-Triazole and 1,3,4-Thiadiazole with Palmitic Acid.

PubMed

Jóźwiak, Michał; Stępień, Karolina; Wrzosek, Małgorzata; Olejarz, Wioletta; Kubiak-Tomaszewska, Grażyna; Filipowska, Anna; Filipowski, Wojciech; Struga, Marta

2018-04-03

Thirty new derivatives of palmitic acid were efficiently synthesized. All obtained compounds can be divided into three groups of derivatives: Thiosemicarbazides (compounds 1 - 10 ), 1,2,4-triazoles (compounds 1a - 10a ) and 1,3,4-thiadiazoles (compounds 1b - 10b ) moieties. ¹H-NMR, 13 C-NMR and MS methods were used to confirm the structure of derivatives. All obtained compounds were tested in vitro against a number of microorganisms, including Gram-positive cocci, Gram-negative rods and Candida albicans . Compounds 4 , 5 , 6 , 8 showed significant inhibition against C. albicans . The range of MIC values was 50-1.56 μg/mL. The halogen atom, especially at the 3rd position of the phenyl group was significantly important for antifungal activity. The biological activity against Candida albicans and selected molecular descriptors were used as a basis for QSAR models, that have been determined by means of multiple linear regression. The models have been validated by means of the Leave-One-Out Cross Validation. The obtained QSAR models were characterized by high determination coefficients and good prediction power.

Superconductivity in the presence of disorder in skutterudite-related La 3Co 4Sn 13 and La 3Ru 4Sn 13 compounds: Electrical transport and magnetic studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Slebarski, A.; Maska, M. M.; Fijalkowski, M.

2015-06-25

La 3Co 4Sn 13 and La 3Ru 4Sn 13 were categorized as BCS superconductors. In a plot of the critical field H c2 vs T, La 3Ru 4Sn 13 displays a second superconducting phase at the higher critical temperature T c*, characteristic of inhomogeneous superconductors, while La 3Co 4Sn 13 shows bulk superconductivity below T c. We observe a decrease in critical temperatures with external pressure and magnetic field for both compounds. Additionally, for La 3Ru 4Sn 13 we find that T c*/dP>dT c/dP. The pressure dependences of T c are interpreted according to the McMillan theory and understood tomore » be a consequence of lattice stiffening. The investigation of the superconducting state of La 3Co xRu 4–xSn 13 shows a T c* that is larger then T c for x < 4. Furthermore, this unique and unexpected observation is discussed as a result of the local disorder and/or the effect of chemical pressure when Ru atoms are partially replaced by smaller Co atoms.« less

New indole, aminoindole and pyranoindole derivatives with anti-inflammatory activity.

PubMed

Nakkady, S S; Fathy, M M; Hishmat, O H; Mahmond, S S; Ebeid, M Y

2000-01-01

6-Methoxy-1-methyl-2,3-diphenyl indol-5-carboxaldehyde (2) was demethylated to give the 6-hydroxy derivative (3) which was cyclized to the pyrano[3,2-f]indole derivatives (4a-d) by the action of ethyl acetoacetate, diethyl malonate, malononitrile, ethyl cyanoacetate. When 4c was boiled in acetic acid, it gave 4d. Reduction of 4c by sodium borohydride yielded the orthoaminonitrile (5). Friedel Craft's acetylation of 1b yielded the 5-acetyl derivative (6), which reacted with hydrazine hydrate, o-toluidine and o-aminophenol to afford (7a-c). Demethylation of (1b) yielded the hydroxyl derivative (8), which differs from compound (9) obtained by demethylation of 6-methoxy-2,3-diphenyl-indole (1a). Friedel Craft's acetylation of 9 gave the 7-acetyl compound (10) which yielded the hydrazone (11). The reaction of primary aromatic amines, (i.e. p-nitroaniline, p-anisidine and p-bromo aniline) with 6-methoxy-1-methyl-2,3-diphenyl-indol-5-carboxaldehyde (2) gave the Schiff bases (12a-c). The latter compounds were reduced by sodium borohydride to yield the corresponding Mannich bases (13a-c). Treatment of 12a-c with thioglycolic acid led to the thiazolidin-4-one-derivatives (14a-c). When (12a-c) reacted with cyanoacetamide, the amino group was replaced by the active methylene to form the cyano compound (15). The structure was confirmed by reacting the carboxaldehyde (2) with cyanoacetamide to yield (15). Pharmacological screening was has been carried out to test the anti-inflammatory activity, ulcerogenecity, effect on the isolated rabbit intestine and the antispasmodic activity.

Synthesis, antimicrobial evaluation and theoretical prediction of NMR chemical shifts of thiazole and selenazole derivatives with high antifungal activity against Candida spp.

NASA Astrophysics Data System (ADS)

Łączkowski, Krzysztof Z.; Motylewska, Katarzyna; Baranowska-Łączkowska, Angelika; Biernasiuk, Anna; Misiura, Konrad; Malm, Anna; Fernández, Berta

2016-03-01

Synthesis and investigation of antimicrobial activities of novel thiazoles and selenazoles is presented. Their structures were determined using NMR, FAB(+)-MS, HRMS and elemental analyses. To support the experiment, theoretical calculations of the 1H NMR shifts were carried out for representative systems within the DFT B3LYP/6-311++G** approximation which additionally confirmed the structure of investigated compounds. Among the derivatives, compounds 4b, 4h, 4j and 4l had very strong activity against reference strains of Candida albicans ATCC and Candida parapsilosis ATCC 22019 with MIC = 0.49-7.81 μg/ml. In the case of compounds 4b, 4c, 4h - 4j and 4l, the activity was very strong against of Candida spp. isolated from clinical materials, i.e. C. albicans, Candida krusei, Candida inconspicua, Candida famata, Candida lusitaniae, Candida sake, C. parapsilosis and Candida dubliniensis with MIC = 0.24-15.62 μg/ml. The activity of several of these was similar to the activity of commonly used antifungal agent fluconazole. Additionally, compounds 4m - 4s were found to be active against Gram-positive bacteria, both pathogenic staphylococci Staphylococcus aureus ATCC with MIC = 31.25-125 μg/ml and opportunistic bacteria, such as Staphylococcus epidermidis ATCC 12228 and Micrococcus luteus ATCC 10240 with MIC = 7.81-31.25 μg/ml.

Effect of organic moieties on the scintillation properties of organic-inorganic layered perovskite-type compounds

NASA Astrophysics Data System (ADS)

Kawano, Naoki; Koshimizu, Masanori; Horiai, Akiyoshi; Nishikido, Fumihiko; Haruki, Rie; Kishimoto, Shunji; Shibuya, Kengo; Fujimoto, Yutaka; Yanagida, Takayuki; Asai, Keisuke

2016-11-01

The effects of organic moieties on the scintillation properties of organic-inorganic layered perovskite-type compounds have been investigated. Three kinds of single crystals were fabricated, namely, (C4H9NH3)2PbBr4 (C4), (C6H5CH2NH3)2PbBr4 (Ben), and (C6H5C2H4NH3)2PbBr4 (Phe). Among the single crystals, the light output of Phe was found to have the greatest value when exposed to X-ray radiation (67.4 keV). The light output of Phe was 0.62 times that of YAP:Ce. The relative values of the light outputs among the fabricated single crystals under X-ray radiation correlated well with those of the quantum efficiencies and the luminescence intensity under ultraviolet radiation.

Cellular internalization and morphological analysis after intravenous injection of a highly hydrophilic octahedral rhenium cluster complex - a new promising X-ray contrast agent.

PubMed

Krasilnikova, Anna A; Solovieva, Anastasiya O; Trifonova, Kristina E; Brylev, Konstantin A; Ivanov, Anton A; Kim, Sung-Jin; Shestopalov, Michael A; Fufaeva, Maria S; Shestopalov, Alexander M; Mironov, Yuri V; Poveshchenko, Alexander F; Shestopalova, Lidia V

2016-11-01

The octahedral cluster compound Na 2 H 8 [{Re 6 Se 8 }(P(C 2 H 4 CONH 2 )(C 2 H 4 COO) 2 ) 6 ] has been shown to be highly radio dense, thus becoming a promising X-ray contrast agent. It was also shown that this compound had low cytotoxic effect in vitro, low acute toxicity in vivo and was eliminated rapidly from the body through the urinary tract. The present contribution describes a more detailed cellular internalization assay and morphological analysis after intravenous injection of this hexarhenium cluster compound at different doses. The median lethal dose (LD 50 ) of intravenously administrated compound was calculated (4.67 ± 0.69 g/kg). Results of the study clearly indicated that the cluster complex H n [{Re 6 Se 8 }(P(C 2 H 4 CONH 2 )(C 2 H 4 COO) 2 ) 6 ] n-10 was not internalized into cells in vitro and induced only moderate morphological alterations of kidneys at high doses without any changes in morphology of liver, spleen, duodenum, or heart of mice. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Monoamine oxidase inhibitory activity of methoxy-substituted chalcones.

PubMed

Mathew, Bijo; Mathew, Githa Elizabeth; Ucar, Gulberk; Joy, Monu; Nafna, E K; Lohidakshan, Krishnakumar K; Suresh, Jerad

2017-11-01

The MAO-B inhibitory activity of chalcone (1, 3- diphenyl-2-propen-1-one) based compounds arise from its structural similarity with 1, 4-diphenyl-2-butene, a known MAO-B inhibitor. Based on our previous report, the methoxy-substituted with fluorine containing chalcones are promising reversible MAO-B inhibitors, while in the present study, a series of methoxylated chalcones (C1-C9) bearing substitution on the para position of ring B was synthesized and evaluated for their human monoamine oxidase inhibitory activity. With the exception of (2E)-1-(4-methoxyphenyl)-3-(4-nitrophenyl) prop-2-en-1-one (C7), which is a nonselective inhibitor, the chalcones exhibited competitive, selective, and reversible inhibition of hMAO-B. The most potent compound, (2E)-3-[4-(dimethylamino) phenyl]-1-(4-methoxyphenyl) prop-2-en-1-one (C5), showed the best inhibitory activity towards hMAO-B (IC 50 =0.29±0.011μM;K i =0.14±0.001μM). The reversibility of MAO-B inhibition by compound C5 was demonstrated by the recovery of enzyme activity after dialysis of mixtures containing enzyme and inhibitor. The reversiblity of C5 was 25.38±1.40 and 92.00±3.87% before and after dialysis, respectively. PAMPA was carried out to evaluate the blood-brain barrier effects of the designated compounds. Moreover, the most potent MAO-B inhibitor, C5, was found to be nontoxic towards cultured hepatic cells at 5 and 25μM, with 97 and 90% viability. Molecular docking study was performed against hMAO-B to observe the binding site interactions of the lead compound. Copyright © 2017 Elsevier B.V. All rights reserved.

Phytochemical Investigations on Chemical Constituents of Achillea tenuifolia Lam

PubMed Central

Moradkhani, Shirin; Kobarfard, Farzad; Ayatollahi, Seyed Abdol Majid

2014-01-01

Achillea tenuifolia Lam. (Asteraceae) afforded a methanolic extract from which after fractionation in solvents with different polarities, two known flavones 3’, 5- dihydroxy- 4’, 6, 7- trimethoxy flavone (eupatorine, compound 3), 5- hydroxy- 3’,4’, 6, 7- tetramethoxyflavone (compound 4), besides stearic acid (compound 1), lupeol (compound 2), daucosterol (β- sitosterol 3-O- β- D- glucopyranoside, compound 5), 2, 4- dihydroxy methyl benzoate (compound 6) were isolated for the first time. The structure of isolated compounds was elucidated by means of different spectroscopic methods such as UV, IR, Mass and 1H- NMR (1D and 2D) and 13C-NMR. For further confirming the structures of isolated compounds, comparison of the spectral data of them with those reported in the litratures have been done. PMID:25276207

Lattice thermal transport in L a3C u3X4 compounds (X =P ,As ,Sb ,Bi ) : Interplay of anharmonicity and scattering phase space

NASA Astrophysics Data System (ADS)

Pandey, Tribhuwan; Polanco, Carlos A.; Lindsay, Lucas; Parker, David S.

2017-06-01

Thermal conductivities of L a3C u3X4 (X =P ,As ,Sb ,Bi ) compounds are examined using first-principles density functional theory and Boltzmann transport methods. We observe a trend of increasing lattice thermal conductivity (κl) with increasing atomic mass, challenging our expectations, as lighter mass systems typically have larger sound speeds and weaker intrinsic scattering. In particular, we find that L a3C u3P4 has the lowest κl, despite having larger sound speed and the most restricted available phase space for phonon-phonon scattering, an important criterion for estimating and comparing κl among like systems. The origin of this unusual behavior lies in the strength of the individual anharmonic phonon scattering matrix elements, which are much larger in L a3C u3P4 than in the heavier L a3C u3B i4 system. Our finding provides insights into the interplay of harmonic and anharmonic properties of complex, low-thermal-conductivity compounds, of potential use for thermoelectric and thermal barrier coating applications.

Magnetic properties of diruthenium(II,III) carboxylate compounds. Crystal structures of Ru2Cl(mu-O2CCH=CHCH=CHMe)4 and Ru2Cl(mu-O2CCH2OMe)4.

PubMed

Barral, M C; Jiménez-Aparicio, R; Pérez-Quintanilla, D; Priego, J L; Royer, E C; Torres, M R; Urbanos, F A

2000-01-10

The reaction of Ru2Cl(mu-O2CMe)4 with 2,4-hexadienoic and 2-methoxyacetic acids affords the compounds Ru2Cl(mu-O2CR)4 [R = CH=CHCH=CHCH3 (1), CH2OMe (2)]. The structures of both complexes have been determined by X-ray crystallography. 1 crystallizes in the triclinic space group P-1 with a = 9.264(1) A, b = 12.661(8) A, c = 12.839(5) A, alpha = 106.09(3) degrees, beta = 77.89(2) degrees, gamma = 97.73(3) degrees, and Z = 2. 2 crystallizes in the nonstandard monoclinic space group P2(1)/c with a = 12.132(4) A, b = 11.570(2) A, c = 13.674(2) A, beta = 91.18(2) degrees, and Z = 4. Complexes 1 and 2 show [Ru2(mu-O2CR)4]+ units linked by chloride ions, giving zigzag chains with Ru-Cl-Ru angles of 119.43(4) degrees and 110.11(7) degrees, respectively. The Ru-Ru bond distances are 2.2857(9) A (1) and 2.290(1) A (2). A magnetic study, in the 2-300 K temperature range, of the new compounds and the previously described Ru2Cl(mu-O2CR)4 [R = CHMe2 (3), CMe3 (4), C4H4N (5)] is described. The polymeric complexes 1 and 2 and the nonpolymeric 3-5 show a large zero-field splitting which varies from 53.9 to 68.1 cm-1. These complexes also show a weak, but not negligible, through-space intermolecular antiferromagnetic coupling not observed in the previous magnetic studies carried out on these types of compounds.

Synthesis and In Vitro Antimicrobial Evaluation of New 1,3,4-Oxadiazoles Bearing 5-Chloro-2-methoxyphenyl Moiety

PubMed Central

Prasanna Kumar, Basavapatna N.; Mohana, Kikkeri N.; Mallesha, Lingappa; Harish, Kikkeri P.

2013-01-01

A series of new 1,3,4-oxadiazole derivatives, 4(a–h), containing 5-chloro-2-methoxy benzohydrazide moiety were synthesized by the reaction of 5-chloro-2-methoxybenzoate with different aromatic carboxylic acids. These newly synthesized compounds were characterized by FT-IR, 1H NMR, mass spectra, and also by elemental analysis. All the newly synthesized compounds were screened for their antibacterial and antifungal activities. Antimicrobial studies revealed that compounds 4c, 4f, and 4g showed significant activity against tested strains. PMID:25374693

A Survey of Compounds from the Antiradiation Drug Development Program of the U.S. Army Medical Research and Development Command

DTIC Science & Technology

1979-09-01

and Development Program, Division of Cancer Treatment, National Cancer Institute. 330. Submitted by the Prevention of Deterioration Center, National...alkylaminoethanethiosulfuric acids have been found to produce a generalized vasoconstriction and myocardial depression in the dog which resulted in...0-4( go 41A 0 49. 4’ le- mAMa 0 0a 0 0 0 54 ý4 %& (n Ř e T C4 C4 4 0 V-4o 0 1-44 AM 00 0 n % 0 C) i 00 r-0 4 C44 C4 en i (V~C 4 t-7 N % 05 5 ll4 0

4-Bromo-N-(di-n-propyl-carbamothioyl)-benzamide.

PubMed

Binzet, Gün; Flörke, Ulrich; Külcü, Nevzat; Arslan, Hakan

2009-02-04

The synthesis of the title compound, C(14)H(19)BrN(2)OS, involves the reaction of 4-bromo-benzoyl chloride with potassium thio-cyanate in acetone followed by condensation of the resulting 4-bromo-benzoyl isothio-cyanate with di-n-propyl-amine. Typical thio-urea carbonyl and thio-carbonyl double bonds, as well as shortened C-N bonds, are observed in the title compound. The short C-N bond lengths in the centre of the mol-ecule reveal the effects of resonance in this part of the mol-ecule. The asymmetric unit of the title compound contains two crystallographically independent mol-ecules, A and B. There is very little difference between the bond lengths and angles of these mol-ecules. In mol-ecule B, one di-n-propyl group is twisted in a -anti-periplanar conformation with C-C-C-H = -179.1 (3)° and the other adopts a -synclinal conformation with C-C-C-H = -56.7 (4)°; in mol-ecule A the two di-n-propyl groups are twisted in + and -anti-periplanar conformations, with C-C-C-H = -179.9 (3) and 178.2 (3)°, respectively. In the crystal, the mol-ecules are linked into dimeric pairs via pairs of N-H⋯S hydrogen bonds.

Characterization and synthesis of volatile compounds from the defensive secretions of some "daddy longlets" (Arachnida: Opiliones: Leiobunum spp.).

PubMed

Jones, T H; Meinwald, J; Hicks, K; Eisner, T

1977-02-01

Analyses of the chief volatile constituents of the defensive secretions of three oplionids were carried out. Leiobunum nigripalpi produces three closely related C7 compounds: E-4-methyl-4-hexen-3-one(I), 4-methylhexan-3-one(II), and 4-methylhexan-3-ol(III), along with E-4-methyl-4-hepten-3-one(IV), E,E-2,4-dimethylhexa-2,4-dienal(IX), and a minor, unidentified component. L. leiopenis secretion contains E-4-methyl-4-hepten-3-one(IV), 4-methylheptan-3-one(V), E,E-2,4-dimethylhexa-2,4-dien-1-ol(VII), and E,E-2,4-dimethylhepta-2,4-dien-1-ol(VIII). L. calcar yields chiefly E-4,6-dimethyl-6-octen-3-one(VI) and E,E-2,4-dimethylhexa-2,4-dien-1-ol(VII). Six of these compounds are new natural products. The structures of these compounds, which can be regarded either as polyketide-derived or as modified isoprenoids, raise interesting biosynthetic questions.

Characterization and synthesis of volatile compounds from the defensive secretions of some "daddy longlets" (Arachnida: Opiliones: Leiobunum spp.).

PubMed Central

Jones, T H; Meinwald, J; Hicks, K; Eisner, T

1977-01-01

Analyses of the chief volatile constituents of the defensive secretions of three oplionids were carried out. Leiobunum nigripalpi produces three closely related C7 compounds: E-4-methyl-4-hexen-3-one(I), 4-methylhexan-3-one(II), and 4-methylhexan-3-ol(III), along with E-4-methyl-4-hepten-3-one(IV), E,E-2,4-dimethylhexa-2,4-dienal(IX), and a minor, unidentified component. L. leiopenis secretion contains E-4-methyl-4-hepten-3-one(IV), 4-methylheptan-3-one(V), E,E-2,4-dimethylhexa-2,4-dien-1-ol(VII), and E,E-2,4-dimethylhepta-2,4-dien-1-ol(VIII). L. calcar yields chiefly E-4,6-dimethyl-6-octen-3-one(VI) and E,E-2,4-dimethylhexa-2,4-dien-1-ol(VII). Six of these compounds are new natural products. The structures of these compounds, which can be regarded either as polyketide-derived or as modified isoprenoids, raise interesting biosynthetic questions. PMID:265514

7-epi-griffonilide, a new lactone from Bauhinia pentandra: complete 1H and 13C chemical shift assignments.

PubMed

Almeida, Macia C S DE; Souza, Luciana G S; Ferreira, Daniele A; Pinto, Francisco C L; Oliveira, Débora R DE; Santiago, Gilvandete M P; Monte, Francisco J Q; Braz-Filho, Raimundo; Lemos, Telma L G DE

2017-01-01

A new lactone, 7-epi-griffonilide (1), and six known compounds, 2, 3a - 3c, 4a and 4b, were isolated from the leaves of Bauhinia pentandra (Fabaceae). The structures elucidation of 1 and 2 were based on detailed 2D NMR techniques and spectral comparison with related compounds, leading to complete assignment of the 1H and 13C NMR spectra.

Diarylsulfonamides and their bioisosteres as dual inhibitors of alkaline phosphatase and carbonic anhydrase: Structure activity relationship and molecular modelling studies.

PubMed

Al-Rashida, Mariya; Ejaz, Syeda Abida; Ali, Sharafat; Shaukat, Aisha; Hamayoun, Mehwish; Ahmed, Maqsood; Iqbal, Jamshed

2015-05-15

The effect of bioisosteric replacement of carboxamide linking group with sulfonamide linking group, on alkaline phosphatase (AP) and carbonic anhydrase (CA) inhibition activity of aromatic benzenesulfonamides was investigated. A series of carboxamide linked aromatic benzenesulfonamides 1a-1c, 2a-2d and their sulfonamide linked bioisosteres 3a-3d, 4a-4d was synthesized and evaluated for inhibitory activity against bovine tissue non-specific alkaline phosphatase (TNAP), intestinal alkaline phosphatase (IAP) and bCA II. A significant increase in CA inhibition activity was observed upon bioisosteric replacement of carboxamide linking group with a sulfonamide group. Some of these compounds were identified as highly potent and selective AP inhibitors. Compounds 1b, 2b, 3d, 4d 5b and 5c were found to be selective bTNAP inhibitors, whereas compounds 1a, 1c, 2a, 2c, 2d, 3a, 3c, 4a, 4b, 4c, 5a were found to be selective bIAP inhibitors. For most active AP inhibitor 3b, detailed kinetic studies indicated a competitive mode of inhibition against tissue non-specific alkaline phosphatase (TNAP) and non-competitive mode of inhibition against intestinal alkaline phosphatase (IAP). Molecular docking studies were carried out to rationalize important binding site interactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Formation of 4-ethoxy-4'-nitrosodiphenylamine in the reaction of the phenacetin metabolite 4-nitrosophenetol with glutathione.

PubMed

Klehr, H; Eyer, P; Schäfer, W

1987-08-01

Phenacetin, a constituent of several analgesic and antipyretic formulations has been made responsible for a variety of toxic and carcinogenic actions. 4-Nitrosophenetol, the N-oxydation product of intermediate 4-phenetidine, forms methemoglobin and binds covalently to sulfhydryl groups of proteins and glutathione. In the reaction of 4-nitrosophenetol with glutathione and other thiols an intermediate so-called "semimercaptal" is formed from which N-(thiol-S-yl)-4-phenetidine S-oxide, N-(thiol-S-yl)-4-phenetidine and 4-phenetidine derive. Besides thiol adducts, a yellow compound is formed which was isolated as a pure crystalline product (elemental analysis) and identified by FAB-MS, EI-MS, 13C-, 1H-NMR, and UV-VIS spectroscopy as 4-ethoxy-4'-nitrosodiphenylamine. This nitrosoarene is formed by an unknown mechanism from 4-nitrosophenetol and 4-phenetidine under liberation of ethanol. In human erythrocytes this compound is easily reduced to 4-amino-4'-ethoxydiphenylamine (FAB-MS, EI-MS, 13C-NMR). During the reaction of 4-nitrosophenetol with red cells only traces of 4-ethoxy-4'-nitrosodiphenylamine were formed, whereas up to 10% appeared as the reduction product 4-amino-4'-ethoxydiphenylamine. This latter compound is unstable in red cells and is metabolized further to unidentified products.

Synthesis of novel (2R,4R)- and (2S,4S)-iso dideoxynucleosides with exocyclic methylene as potential antiviral agents.

PubMed

Yoo, Su Jeong; Kim, Hea Ok; Lim, Yoongho; Kim, Jeongmin; Jeong, Lak Shin

2002-01-01

Novel (2R,4R)- and (2S,4S)-iso dideoxynucleosides with exocyclic methylene have been designed and synthesized, based on the lead BMS-200475 (3) which exhibited potent anti-HBV activity. For the synthesis of D types of (2R,4R)-nucleosides, L-xylose was converted to the key intermediate 14. The intermediate 14 was converted to the uracil derivative 4a and the cytosine derivative 4b. Compound 14 was also converted to the purine derivatives such as adenine derivative 4c, hypoxanthine derivative 4d, and guanine derivative 4e. The corresponding L types of (2S,4S)-enantiomers were more efficiently synthesized from the commercially available 1,2-isopropylidene-D-xylose (20) than the synthetic method used in the synthesis of (2R,4R)-nucleosides. The key intermediate 25 was converted to the pyrimidine analogues 5a and 5b and the purine derivatives 5c, 5d, and 5e using the similar method used in the preparation of 4c, 4d, and 4e. The synthesized final (2R,4R)- and (2S,4S)-nucleosides were tested against several viruses such as HIV-1, HSV-1, HSV-2, HCMV and HBV. (2R,4R)-Adenine analogue 4c exhibited potent anti-HBV activity (EC(50)=1.5 microM in 2.2.15 cells) among compounds tested, while (2R,4R)-uracil derivative 4a was the most active against HCMV among compounds tested and (2R,4R)-adenine derivative 4c was found to be moderately active against the same virus. However, the corresponding (2S,4S)-isomers were found to be totally inactive against all tested viruses. Both (2R,4R)-adenine derivative 4c and (2S,4S)-adenine analogue 5c were totally resistant to the adenosine deaminase like iso-ddA (1). From the molecular modeling study the hydroxymethyl side chains of BMS-200475 (3) and 4c were almost overlapped, indicating that 4c may be suitable for phosphorylation by cellular kinases like the lead 3, but some discrepancy between two bases was observed, indicating why 4c is less potent against HBV than 3. It is concluded that discovery of (2R,4R)-adenine analogue 4c as potent anti-HBV agent suggested that the sugar moiety of this series can be regarded as a novel template for the development of new anti-HBV agent and oxygen atom can be acted as a bioisostere of C-OH.

Method of producing ternary lead molybdenum sulfides

DOEpatents

Foner, Simon; McNiff, Jr., Edward J.; Alexander, Edwin J.

1977-02-01

The method of preparing Pb.sub.x Mo.sub.y S.sub.z where x = 0.8-1.1, y = 4.5-5.6, and z = 5.4-7.2 comprising the steps of mixing commercial reagent grade powders of the reactants, heating in a sealed, evacuated reaction vessel to a temperature of 950.degree.-1150.degree. C, maintaining the temperature until the compound is formed, and then cooling the compound at a controlled rate not in excess of 4.degree. C per minute.

Synthesis, docking study and neuroprotective effects of some novel pyrano[3,2-c]chromene derivatives bearing morpholine/phenylpiperazine moiety.

PubMed

Sameem, Bilqees; Saeedi, Mina; Mahdavi, Mohammad; Nadri, Hamid; Moghadam, Farshad Homayouni; Edraki, Najmeh; Khan, Muhammad Imran; Amini, Mohsen

2017-08-01

Novel pyrano[3,2-c]chromene derivatives bearing morpholine/phenylpiperazine moiety were synthesized and evaluated against acetylcholinestrase (AChE) and butylcholinestrase (BuChE). Among the synthesized compounds, N-(3-cyano-4-(4-methoxyphenyl)-5-oxo-4,5-dihydropyrano[3,2-c]chromen-2-yl)-2-(4-phenylpiperazin-1-yl)acetamide (6c) exhibited the highest acetylcholinestrase inhibitory (AChEI) activity (IC 50 =1.12µM) and most of them showed moderate butylcholinestrase inhibitory activity (BChEI). Kinetic study of compound 6c confirmed mixed type of inhibition towards AChE which was in covenant with the results obtained from docking study. Also, it was evaluated against β-secretase which demonstrated low activity (inhibition percentage: 18%). It should be noted that compounds 6c, 7b, 6g, and 7d showed significant neuroprotective effects against H 2 O 2 -induced PC12 oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

PhMYB4 fine-tunes the floral volatile signature of Petunia x hybrida through PhC4H.

PubMed

Colquhoun, Thomas A; Kim, Joo Young; Wedde, Ashlyn E; Levin, Laura A; Schmitt, Kyle C; Schuurink, Robert C; Clark, David G

2011-01-01

In Petunia × hybrida cv 'Mitchell Diploid' (MD), floral volatile benzenoid/phenylpropanoid (FVBP) biosynthesis is controlled spatially, developmentally, and daily at molecular, metabolic, and biochemical levels. Multiple genes have been shown to encode proteins that either directly catalyse a biochemical reaction yielding FVBP compounds or are involved in metabolite flux prior to the formation of FVBP compounds. It was hypothesized that multiple transcription factors are involved in the precise regulation of all necessary genes, resulting in the specific volatile signature of MD flowers. After acquiring all available petunia transcript sequences with homology to Arabidopsis thaliana R2R3-MYB transcription factors, PhMYB4 (named for its close identity to AtMYB4) was identified, cloned, and characterized. PhMYB4 transcripts accumulate to relatively high levels in floral tissues at anthesis and throughout open flower stages, which coincides with the spatial and developmental distribution of FVBP production and emission. Upon RNAi suppression of PhMYB4 (ir-PhMYB4) both petunia cinnamate-4-hydroxylase (PhC4H1 and PhC4H2) gene transcript levels were significantly increased. In addition, ir-PhMYB4 plants emit higher levels of FVBP compounds derived from p-coumaric acid (isoeugenol and eugenol) compared with MD. Together, these results indicate that PhMYB4 functions in the repression of C4H transcription, indirectly controlling the balance of FVBP production in petunia floral tissue (i.e. fine-tunes).

Potential chemical markers for the identification of irradiated sausages.

PubMed

Kwon, Joong Ho; Akram, Kashif; Nam, Ki Chang; Min, Byungrok; Lee, Eun Joo; Ahn, Dong U

2012-09-01

Hydrocarbons, gas compounds, and off-odor volatiles were determined for irradiated (0 or 5 kGy) commercial sausages with different fat contents (16% and 29%) during a 60-d storage period at 4 °C. Total of 4 hydrocarbons (C14:1, C15:0, C16:2, and C17:1) were detected only in irradiated sausages: the amount of C16:2 was the highest, followed by C17:1, C14:1, and C15:0. The concentrations of hydrocarbons decreased significantly (P < 0.05) with storage, but were still detectable at the end of 60-d storage. Irradiated sausages produced significantly higher amounts of CO than the nonirradiated ones. CH(4) was detected only in irradiated sausages. Dimethyl disulfide was detected only in irradiated sausages and its concentration decreased significantly (P < 0.05) with storage. Fat content of sausages showed a significant effect on the production and retention of hydrocarbons, gas compounds, and sulfur volatiles in irradiated sausages during storage. Some hydrocarbons (C16:2, C17:1, C14:1, and C15:0), CH(4) , and dimethyl disulfide were only found in irradiated sausages indicating that these compounds can be used as potential markers for irradiated sausages. © 2012 Institute of Food Technologists®

Structures, bonding, and reaction chemistry of the neutral organogallium(I) compounds (GaAr)n(n = 1 or 2) (Ar = terphenyl or related ligand): an experimental investigation of Ga-Ga multiple bonding.

PubMed

Hardman, Ned J; Wright, Robert J; Phillips, Andrew D; Power, Philip P

2003-03-05

The synthesis, structure, and properties of several new organogallium(I) compounds are reported. The monovalent compounds GaAr* (Ar* = C(6)H(3)-2,6-Trip(2), Trip = C(6)H(2)-2,4,6-Pr(i)()(3), 1), GaAr# (Ar# = C(6)H(3)-2,6(Bu(t)Dipp)(2), Bu(t)Dipp = C(6)H(2)-2,6-Pr(i)(2)-4-Bu(t)(), 4), and the dimeric (GaAr')(2) (Ar' = C(6)H(3)-2,6-Dipp(2), Dipp = C(6)H(3)-2,6-Pr(i)(2), 6) were synthesized by the reaction of "GaI" with (Et(2)O)LiAr*, (Et(2)O)LiAr# (3), or (LiAr')(2). Compounds 1 and 4 were isolated as green crystals, whereas 6 was obtained as a brown-red crystalline solid. All three compounds dissolved in hydrocarbon solvents to give green solutions and almost identical UV/visible spectra. Cryoscopy of 1 and 6 showed that they were monomeric in cyclohexane. Crystals of 1 and 4 were unsuitable for X-ray crystal structure determinations, but an X-ray data set for 6 showed that it was weakly dimerized in the solid with a long Ga-Ga bond of 2.6268(7) A and a trans-bent CGaGaC core array. The 1,2-diiodo-1,2-diaryldigallane compounds [Ga(Ar*)I](2) (2), [Ga(Ar#)I](2) (5), and [Ga(Ar')I](2) (7) were isolated as byproducts of the synthesis of 1, 4, and 6. The crystal structures of 2 and 7 showed that they had planar ICGaGaCI core arrays with Ga-Ga distances near 2.49 A, consistent with Ga-Ga single bonding. Treatment of 1, 4, and 6 with B(C(6)F(5))(3) immediately afforded the 1:1 donor-acceptor complexes ArGa[B(C(6)F(5))(3)] (Ar = Ar*, 8; Ar#, 9; Ar', 10) that featured almost linear gallium coordination, Ga-B distances near the sum of the covalent radii of gallium and boron, as well as some close Ga...F contacts. Compound 1 also reacted with Fe(CO)(5) under ambient conditions to give Ar*GaFe(CO)(4) (11), which had been previously synthesized by the reaction of GaAr*Cl(2) with Na(2)Fe(CO)(4). Reaction of 1 with 2,3-dimethyl-1,3-butadiene afforded the compound [Ar*GaCH(2)C(Me)C(Me)CH(2)]2 (12) that had a 10-membered 1,5-Ga(2)C(8) ring with no Ga-Ga interaction. Stirring 1 or 6 with sodium readily gave Na(2)[Ar*GaGaAr*] (13) and Na(2)(Ar'GaGaAr') (14). The former species 13 had been synthesized previously by reduction of GaAr*Cl(2) with sodium and was described as having a Ga-Ga triple bond because of the short Ga-Ga distance and the electronic relationship between [Ar*GaGaAr*](2-) and the corresponding neutral group 14 alkyne analogues. Compound 14 has a similar structure featuring a trans-bent CGaGaC core, bridged by sodiums which were also coordinated to the flanking aryl rings of the Ar' ligands. The Ga-Ga bond length was found to be 2.347(1) A, which is slightly (ca. 0.02 A) longer than that reported for 13. Reaction of Ga[N(Dipp)C(Me)](2)CH, 15 (i.e., GaN(wedge)NDipp(2)), which is sterically related to 1, 4, and 6, with Fe(CO)(5) yielded Dipp(2)N(wedge)NGaFe(CO)(4) (16), whose Ga-Fe bond is slightly longer than that observed in 11. Reaction of the less bulky LiAr"(Ar"= C(6)H(3)-2,6-Mes(2)) with "GaI" afforded the new paramagnetic cluster Ga(11)Ar(4)" (17). The ready dissociation of 1, 4, and 6 in solution, the long Ga-Ga distance in 6, and the chemistry of these compounds showed that the Ga-Ga bonds are significantly weaker than single bonds. The reduction of 1 and 6 with sodium to give 13 and 14 supplies two electrons to the di-gallium unit to generate a single bond (in addition to the weak interaction in the neutral precursor) with retention of the trans-bent geometry. It was concluded that the stability of 13 and 14 depends on the matching size of the sodium ion, and the presence of Na-Ga and Na-Ar interactions that stabilize their Na(2)Ga(2) core structures.

Crystal structure and Hirshfeld surface analysis of (2E,2'E)-3,3'-(1,4-phenyl-ene)bis-[1-(2,4-di-fluoro-phen-yl)prop-2-en-1-one].

PubMed

Kwong, Huey Chong; Sim, Aijia; Chidan Kumar, C S; Then, Li Yee; Win, Yip-Foo; Quah, Ching Kheng; Naveen, S; Warad, Ismail

2017-12-01

The asymmetric unit of the title compound, C 24 H 14 F 4 O 2 , comprises of one and a half mol-ecules; the half-mol-ecule is completed by crystallographic inversion symmetry. In the crystal, mol-ecules are linked into a three-dimensional network by C-H⋯F and C-H⋯O hydrogen bonds. Some of the C-H⋯F links are unusually short (< 2.20 Å). Hirshfeld surface analyses ( d norm surfaces and two-dimensional fingerprint plots) for the title compound are presented and discussed.

Six new C21 steroidal glycosides from Asclepias curassavica L.

PubMed

Li, Jun-Zhu; Liu, Hai-Yang; Lin, Yi-Ju; Hao, Xiao-Jiang; Ni, Wei; Chen, Chang-Xiang

2008-07-01

Six new C(21) steroidal glycosides, named curassavosides A-F (3-8), were obtained from the aerial parts of Asclepias curassavica (Asclepiadaceae), along with two known oxypregnanes, 12-O-benzoyldeacylmetaplexigenin (1) and 12-O-benzoylsarcostin (2). By spectroscopic methods, the structures of the six new compounds were determined as 12-O-benzoyldeacylmetaplexigenin 3-O-beta-D-oleandropyranosyl-(1-->4)-beta-D-digitoxopyranoside (3), 12-O-benzoylsarcostin 3-O-beta-D-oleandropyranosyl-(1-->4)-beta-D-digitoxopyranoside (4), sarcostin 3-O-beta-D-oleandropyranosyl-(1-->4)-beta-D-canaropyranosyl-(1-->4)-beta-D-oleandropyranosyl-(1-->4)-beta-D-digitoxopyranoside (5), sarcostin 3-O-beta-D-oleandropyranosyl-(1-->4)-beta-D-canaropyranosyl-(1-->4)-beta-D-canaropyranosyl-(1-->4)-beta-D-digitoxopyranoside (6), 12-O-benzoyldeacylmetaplexigenin 3-O-beta-D-glucopyranosyl-(1-->4)-beta-D-oleandropyranosyl-(1-->4)-beta-D-canaropyranosyl-(1-->4)-beta-d-oleandropyranosyl-(1-->4)-beta-D-digitoxopyranoside (7), and 12-O-benzoylsarcostin 3-O-beta-D-glucopyranosyl-(1-->4)-beta-D-oleandropyranosyl-(1-->4)-beta-d-canaropyranosyl-(1-->4)-beta-D-oleandropyranosyl-(1-->4)-beta-D-digitoxopyranoside (8), respectively. All compounds (1-8) were tested for in vitro cytotoxicity; only compound 3 showed weak inhibitory activity against Raji and AGZY cell lines.

Synthesis of [.sup.13C] and [.sup.2H] substituted methacrylic acid, [.sup.13C] and [.sup.2H] substituted methyl methacrylate and/or related compounds

DOEpatents

Alvarez, Marc A.; Martinez, Rodolfo A.; Unkefer, Clifford J.

2010-02-16

The present invention is directed to labeled compounds of the formulae ##STR00001## wherein Q is selected from the group consisting of --S(.dbd.O)--, and --S(.dbd.O).sub.2--, Z is selected from the group consisting of 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, and phenyl groups with the structure ##STR00002## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each independently selected from the group consisting of hydrogen, a C.sub.1-C.sub.4 lower alkyl, a halogen, and an amino group selected from the group consisting of NH.sub.2, NHR and NRR' where R and R' are each independently selected from the group consisting of a C.sub.1-C.sub.4 lower alkyl, an aryl, and an alkoxy group, and X is selected from the group consisting of hydrogen, a C.sub.1-C.sub.4 lower alkyl group, and a fully-deuterated C.sub.1-C.sub.4 lower alkyl group.

Cyclopentadienyl-bis(oxazoline) magnesium and zirconium complexes in aminoalkene hydroaminations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eedugurala, Naresh; Hovey, Megan; Ho, Hung -An

Here, a new class of cyclopentadiene-bis(oxazoline) compounds and their piano-stool-type organometallic complexes have been prepared as catalysts for hydroamination of aminoalkenes. The two compounds MeC(Ox Me2) 2C 5H 5 (Bo MCpH; Ox Me2 = 4,4-dimethyl-2-oxazoline) and MeC(Ox Me2) 2C 5Me 4H (Bo MCp tetH) are synthesized from C 5R 4HI (R = H, Me) and MeC(Ox Me2) 2Li. These cyclopentadiene-bis(oxazolines) are converted into ligands that support a variety of metal centers in piano-stool-type geometries, and here we report the preparation of Mg, Tl, Ti, and Zr compounds. Bo MCpH and Bo MCp tetH react with MgMe 2(O 2C 4H 8)more » 2 to give the magnesium methyl complexes {Bo MCp}MgMe and {Bo MCp tet}MgMe. Bo MCpH and Bo MCp tetH are converted to Bo MCpTl and Bo MCp tetTl by reaction with TlOEt. The thallium derivatives react with TiCl 3(THF) 3 to provide [{Bo MCp}TiCl(μ-Cl)] 2 and [{Bo MCptet}TiCl(μ-Cl)] 2, the former of which is crystallographically characterized as a dimeric species. Bo MCpH and Zr(NMe 2) 4 react to eliminate dimethylamine and afford {Bo MCp}Zr(NMe 2) 3, which is crystallographically characterized as a monomeric four-legged piano-stool compound. {Bo MCp}Zr(NMe 2) 3, {Bo MCp}MgMe, and {Bo MCp tet}MgMe are efficient catalysts for the hydroamination/cyclization of aminoalkenes under mild conditions.« less

Cyclopentadienyl-bis(oxazoline) magnesium and zirconium complexes in aminoalkene hydroaminations

DOE PAGES

Eedugurala, Naresh; Hovey, Megan; Ho, Hung -An; ...

2015-11-25

Here, a new class of cyclopentadiene-bis(oxazoline) compounds and their piano-stool-type organometallic complexes have been prepared as catalysts for hydroamination of aminoalkenes. The two compounds MeC(Ox Me2) 2C 5H 5 (Bo MCpH; Ox Me2 = 4,4-dimethyl-2-oxazoline) and MeC(Ox Me2) 2C 5Me 4H (Bo MCp tetH) are synthesized from C 5R 4HI (R = H, Me) and MeC(Ox Me2) 2Li. These cyclopentadiene-bis(oxazolines) are converted into ligands that support a variety of metal centers in piano-stool-type geometries, and here we report the preparation of Mg, Tl, Ti, and Zr compounds. Bo MCpH and Bo MCp tetH react with MgMe 2(O 2C 4H 8)more » 2 to give the magnesium methyl complexes {Bo MCp}MgMe and {Bo MCp tet}MgMe. Bo MCpH and Bo MCp tetH are converted to Bo MCpTl and Bo MCp tetTl by reaction with TlOEt. The thallium derivatives react with TiCl 3(THF) 3 to provide [{Bo MCp}TiCl(μ-Cl)] 2 and [{Bo MCptet}TiCl(μ-Cl)] 2, the former of which is crystallographically characterized as a dimeric species. Bo MCpH and Zr(NMe 2) 4 react to eliminate dimethylamine and afford {Bo MCp}Zr(NMe 2) 3, which is crystallographically characterized as a monomeric four-legged piano-stool compound. {Bo MCp}Zr(NMe 2) 3, {Bo MCp}MgMe, and {Bo MCp tet}MgMe are efficient catalysts for the hydroamination/cyclization of aminoalkenes under mild conditions.« less

Job Language Performance Requirements for MOS 12B. Combat Engineer. Reference Soldier’s Manual Dated 29 November 1977.

DTIC Science & Technology

1977-11-29

and direct/indirect object Many things cause burns. 3. Subject and linking verb and subjective complement This is very important. COMPOUND : Two or more...1- 1.2 13. 6 MICROCOP REOLTONTETCHR AIM UI A 0S&MM " qq4 -41 CC fn 0 0r %- q o on 41 . .-4 4 W - . .X -4 C,0I 0 mC4- 46- � 14 f .1- .44 .04 9% Ci r...Imperative command, polite request D. Exclamatory exclamation * Sentence Complexity: A. Simple one full subject and predicate B. Compound two or more

Preparation, structural characterization, and decomposition studies of two new γ-octamolybdates of 4-methylpyridine.

PubMed

Szymańska, Anna; Nitek, Wojciech; Rutkowska-Zbik, Dorota; Łasocha, Wiesław

We synthesized two new γ-octamolybdates, and determined their crystal structures from single-crystal X-ray diffraction data. Orange-yellow tetrakis(4-methylpyridinium) bis(4-methylpyridine)-γ-octamolybdate 1 crystallizes in space group P2 1 /c with a  = 11.586(2) Å, b  = 15.526(2) Å, c  = 16.247(2) Å, β  = 118.753(1)º, Z  = 2. White tetrakis(4-methylpyridinium) bis(4-methylpyridine)-γ-octamolybdate hydrate 2 crystallizes in space group C2/c with a  = 27.086(4) Å, b  = 11.917(2) Å, c  = 19.332(2) Å, β  = 124.427(1)º, Z  = 4. Results of crystal structure determinations are presented and discussed in this paper. Thermal stability and decomposition studies of the obtained two new γ-octamolybdates were performed using TG/DSC and XRPD methods. Both compounds decomposed with the formation of 4-methylpyridinium β-octamolybdate. The two compounds are pseudo-polymorphs, exhibiting both striking similarities as well as significant differences in their structures and properties.

Diterpenoid natural compound C4 (Crassin) exerts cytostatic effects on triple-negative breast cancer cells via a pathway involving reactive oxygen species.

PubMed

Richards, Cathy E; Vellanki, Sri H; Smith, Yvonne E; Hopkins, Ann M

2018-02-01

Triple-negative breast cancers (TNBC) lack expression of three common cell surface receptors, i.e., estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2). Accordingly, TNBCs are associated with fewer treatment options and a relatively poor prognosis. Having screened a National Cancer Institute natural compound library, the purpose of this study was to investigate the bioactivity of compound C4 (Crassin) in TNBC cells. Cell viability assays were performed in two TNBC cell lines, MDA-MB-231 and 4T1, following C4 treatment in the presence or absence of the antioxidant N-acetyl-L-cysteine (NAC). Phosphorylation of Akt and ERK was assessed by Western blotting. Apoptosis, necrosis, autophagy, necroptosis, ferroptosis and cytostasis assays were performed to explain viability deficits resulting from C4 exposure. We found that the viability of the TNBC cells tested decreased in a concentration- and time-dependent fashion following C4 treatment. This decrease coincided with an unexpected increase in the expression of the cell survival effectors pAkt and pERK. In addition, we found that both the decreased cell viability and the increased pAkt/pERK levels could be rescued by the antioxidant NAC, suggesting a central role for reactive oxygen species (ROS) in the mechanism of action of C4. Necrosis, apoptosis, necroptosis and ferroptosis could be ruled out as cell death mechanisms. Instead, we found that C4 induced cytostasis downstream of ROS activation. Finally, we observed a synergistic effect between C4 and the chemotherapeutic drug doxorubicin in TNBC cells. From our in vitro data we conclude that C4 exerts cytostatic effects on triple-negative breast cancer cells via a pathway involving reactive oxygen species. Its potential value in combination with cytotoxic therapies merits deeper investigation in pre-clinical models.

Ring opening and carbonylation of 3,3-dimethylthietane ligands in ruthenium carbonyl cluster complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, R.D.; Belinski, J.A.; Yamamoto, J.H.

1992-10-01

When heated to 97{degrees}C, the complex Ru{sub 4}(CO){sub 12}[{mu}-SCH{sub 2}CMe{sub 2}CH{sub 2}]2 (1) was transformed into two new hexaruthenium cluster complexes, Ru{sub 6}(CO){sub 13}({mu}{sub 3}-SCH{sub 2}CMe{sub 2}CH{sub 2}){sub 4} (2) and Ru{sub 6}(CO){sub 12}({mu}-SCH{sub 2}CMe{sub 2}CH{sub 2})({mu}{sub 3}-SCH{sub 2}CMe{sub 2}CH{sub 2}){sub 3}[{mu}{sub 3}-SCH{sub 2}C(Me)(CH{sub 2})CH{sub 2}] ({mu}-H) (3), that contain four and five ring-opened 3,3-dimethylthietane (3,3-DMT) ligands, respectively. In compound 3 one of the ring-opened DMT ligands has also undergone a CH activation on one of the methyl groups. Compound 2 reacts with additional 3,3-DMT at 97{degrees}C to form 3 in 18% yield. When treated with CO at 95{degrees}C (500more » psi), compound 2 yielded 4,4-dimethylthiobutyrolactone and Ru{sub 3}(CO){sub 12}. It was also found that the complex Os{sub 3}(CO){sub 11-}(SCH{sub 2}CMe{sub 2}CH{sub 2}C{double_bond}O) (4) yields 4,4-dimethylthiobutyrolactone when treated with CO at 120{degrees}C (1200 psi). Crystal data for 2: space group P2{sub 1}/n, {alpha} = 22.652 (7) A, {beta} = 11.712 (2) A, c = 19.965 (6) A, {Beta} = 115.75 (2){degrees} Z = 4, 3665 reflections, R = 0.021. Crystal data for 3: space group P2{sub 1}/c, {alpha} = 17.332 (8) A, {Beta} = 14.668 (9) A, c = 19.823 (9) A, {Beta} = 91.27 (4){degrees}, Z = 4, 1875 reflections, R = 0.050. 13 refs., 2 figs., 13 refs.« less

Effect of heat treatment and storage conditions on mead composition.

PubMed

Kahoun, David; Řezková, Soňa; Královský, Josef

2017-03-15

The effects of heat treatment and storage conditions on the composition of pure mead (honey wine) made from only honey and water were investigated. Heat treatment experiments were performed at 7 different temperatures ranging from 40°C to100°C with 10°C increments for 60min. Storage condition experiments were performed at room temperature (20-25°C) in daylight without direct sunlight and in darkness in a refrigerator at 4°C for 1, 2, 4 and 12weeks. The parameters evaluated were phenolic compounds, peak area of unidentified compounds, 5-hydroxymethylfurfural content and antioxidant capacity. Significant changes in compound content were observed in the case of 6 identified compounds and 9 unidentified compounds. However, the antioxidant activity was not affected by the heat treatments or storage at room temperature. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis and Biological Evaluation of 2-Methyl-4,5-Disubstituted Oxazoles as a Novel Class of Highly Potent Antitubulin Agents

NASA Astrophysics Data System (ADS)

Romagnoli, Romeo; Baraldi, Pier Giovanni; Prencipe, Filippo; Oliva, Paola; Baraldi, Stefania; Salvador, Maria Kimatrai; Lopez-Cara, Luisa Carlota; Brancale, Andrea; Ferla, Salvatore; Hamel, Ernest; Ronca, Roberto; Bortolozzi, Roberta; Mariotto, Elena; Porcù, Elena; Basso, Giuseppe; Viola, Giampietro

2017-04-01

Antimitotic agents that interfere with microtubule formation are one of the major classes of cytotoxic drugs for cancer treatment. Multiple 2-methyl-4-(3‧,4‧,5‧-trimethoxyphenyl)-5-substituted oxazoles and their related 4-substituted-5-(3‧,4‧,5‧-trimethoxyphenyl) regioisomeric derivatives designed as cis-constrained combretastatin A-4 (CA-4) analogues were synthesized and evaluated for their antiproliferative activity in vitro against a panel of cancer cell lines and, for selected highly active compounds, interaction with tubulin, cell cycle effects and in vivo potency. Both these series of compounds were characterized by the presence of a common 3‧,4‧,5‧-trimethoxyphenyl ring at either the C-4 or C-5 position of the 2-methyloxazole ring. Compounds 4g and 4i, bearing a m-fluoro-p-methoxyphenyl or p-ethoxyphenyl moiety at the 5-position of 2-methyloxazole nucleus, respectively, exhibited the greatest antiproliferative activity, with IC50 values of 0.35-4.6 nM (4g) and 0.5-20.2 nM (4i), which are similar to those obtained with CA-4. These compounds bound to the colchicine site of tubulin and inhibited tubulin polymerization at submicromolar concentrations. Furthermore, 4i strongly induced apoptosis that follows the mitochondrial pathway. In vivo, 4i in a mouse syngeneic model demonstrated high antitumor activity which significantly reduced the tumor mass at doses ten times lower than that required for CA-4P, suggesting that 4i warrants further evaluation as a potential anticancer drug.

Molecular and crystal structure of 2-{( E)-[(4-Methylphenyl)imino]methyl}-4-nitrophenol: A redetermination

NASA Astrophysics Data System (ADS)

Kaynar, Nihal Kan; Tanak, Hasan; Şahin, Songul; Dege, Necmi; Ağar, Erbil; Yavuz, Metin

2016-03-01

The crystal structure of the title compound, C14H12N2O3, was recently determined as a mixture of its neutral (OH containing) and zwitterionic (NH containing) forms, in a 0.60 (4): 0.40 (4) ratio using the X-ray determination. In this study, the title compound has been characterized by FT-IR and X-ray diffraction. The redetermination showed that the title compound has only enol (OH) form because of lack of the NH stretching vibration in FT-IR spectrum. In addition, the molecular structure and tautomerism of the title compound have been discussed.

Molecular and crystal structure of 2-((E)-[(4-Methylphenyl)imino]methyl)-4-nitrophenol: A redetermination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaynar, Nihal Kan, E-mail: nihal-kan84@windowslive.com; Tanak, Hasan; Şahin, Songul

The crystal structure of the title compound, C{sub 14}H{sub 12}N{sub 2}O{sub 3}, was recently determined as a mixture of its neutral (OH containing) and zwitterionic (NH containing) forms, in a 0.60 (4): 0.40 (4) ratio using the X-ray determination. In this study, the title compound has been characterized by FT-IR and X-ray diffraction. The redetermination showed that the title compound has only enol (OH) form because of lack of the NH stretching vibration in FT-IR spectrum. In addition, the molecular structure and tautomerism of the title compound have been discussed.

Solvothermal synthesis and structural characterization of a three-dimensional metal organic polymer [NaZn(1,2,4-BTC)] (1,2,4-BTC=1,2,4-benzenetricarboxylate)

NASA Astrophysics Data System (ADS)

Wang, Lei; Shi, Zhan; Li, Guanghua; Fan, Yong; Fu, Wensheng; Feng, Shouhua

2004-01-01

A new three-dimensional metal-organic polymer, [NaZn(1,2,4-BTC)] (where 1,2,4-BTC=1,2,4-benzenetricarboxylate), has been prepared under solvothermal conditions and characterized by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P2 1/ c, with cell parameters: a=9.7706(4) Å, b=12.3549(5) Å, c=6.8897(3) Å, β=91.640(2)°, V=831.35(6) Å 3 and Z=4. In the three-dimensional structure of the compound, each Zn atom is five-coordinated in distorted trigonal bipyramidal geometry, while the sixfold coordination of Na corresponds to a slightly distorted triangular prism. The organic ligand, 1,2,4-BTC, shows a novel and unprecedented coordination mode: 11 bonds to 10 metals with each carboxylate function exhibiting different linkages. It remains stable when desolvated and when heated up to 410 °C.

Crystal structures, in-silico study and anti-microbial potential of synthetic monocarbonyl curcuminoids

NASA Astrophysics Data System (ADS)

Ud Din, Zia; Serrano, N. F. G.; Ademi, Kastriot; Sousa, C. P.; Deflon, Victor Marcelo; Maia, Pedro Ivo da Silva; Rodrigues-Filho, Edson

2017-09-01

In this work the screening of 20 unsymmetrical chalcone and curcuminoids analogues in regard of their antimicrobial properties was conducted. Electron donating groups in the aromatic rings in the chalcone and curcuminoid derivatives produced higher antimicrobial effect. Compounds 1, 9 and 15 exhibited good activity against Escherichia coli and Staphylococcus aureus. These compounds were further evaluated against nine micro-organisms of pathological interest. Pharmmaper was used for target fishing of compounds against important bacterial targets. Molecular Docking helped to verify the results of these compounds against the selected bacterial target D-alanyl-D-alanine carboxypeptidase (PDB ID: 1PW1). The crystal structure of ligand and docked conformers in the active site of 1PW1 were analyzed. As a result structure-activity relationships are proposed. Structures of compounds 14 and 16 were obtained through single crystals X-ray diffraction studies. Compound 14 crystallizes in monoclinic space group P21/c with unit cell dimensions a = 13.1293(3) Å, b = 17.5364(4) Å, c = 15.1433(3) Å, β = 95.6440(10), V = 3469.70(13) Å3 and Z = 8. Compound 16 crystallizes in triclinic space group Pī with unit cell dimensions a = 6.8226(4) Å, b = 7.2256(4) Å, c = 18.1235(12) Å, β = 87.322(4), V = 850.57(9) Å3 and Z = 2.

The antioxidant activity of some curcuminoids and chalcones.

PubMed

Sökmen, Münevver; Akram Khan, M

2016-06-01

The antioxidant properties of the synthetic compound (C1)-(C8), which comprised 7 curcuminoids and a chalcone, were evaluated by two complementary assays, DPPH and β-carotene/linoleic acid. It was found that, in general, the free radical scavenging ability of (C1)-(C8) was concentration-dependent. Compounds (C1) and (C4), which contained (4-OH) phenolic groups, were found to be highly potent antioxidants with higher antioxidant values than BHT suggesting that synthetic curcuminoids are more potent antioxidants than standard antioxidants like BHT. Using β-carotene-linoleic acid assay, only the water-soluble 2, 4,6-trihydroxyphenolic chalcone (C5) showed 85.2 % inhibition of the formation of conjugated dienes reflecting on its potent antioxidant activity.

CYP3A4-dependent cellular response does not relate to CYP3A4-catalysed metabolites of C-1748 and C-1305 acridine antitumor agents in HepG2 cells.

PubMed

Augustin, Ewa; Niemira, Magdalena; Hołownia, Adam; Mazerska, Zofia

2014-11-01

High CYP3A4 expression sensitizes tumor cells to certain antitumor agents while for others it can lower their therapeutic efficacy. We have elucidated the influence of CYP3A4 overexpression on the cellular response induced by antitumor acridine derivatives, C-1305 and C-1748, in two hepatocellular carcinoma (HepG2) cell lines, Hep3A4 stably transfected with CYP3A4 isoenzyme, and HepC34 expressing empty vector. The compounds were selected considering their different chemical structures and different metabolic pathways seen earlier in human and rat liver microsomes C-1748 was transformed to several metabolites at a higher rate in Hep3A4 than in HepC34 cells. In contrast, C-1305 metabolism in Hep3A4 cells was unchanged compared to HepC34 cells, with each cell line producing a single metabolite of comparable concentration. C-1748 resulted in a progressive appearance of sub-G1 population to its high level in both cell lines. In turn, the sub-G1 fraction was dominated in CYP3A4-overexpressing cells following C-1305 exposure. Both compounds induced necrosis and to a lesser extent apoptosis, which were more pronounced in Hep3A4 than in wild-type cells. In conclusion, CYP3A4-overexpressing cells produce higher levels of C-1748 metabolites, but they do not affect the cellular responses to the drug. Conversely, cellular response was modulated following C-1305 treatment in CYP3A4-overexpressing cells, although metabolism of this drug was unaltered. © 2014 International Federation for Cell Biology.

Synthesis of a stationary phase based on silica modified with branched octadecyl groups by Michael addition and photoinduced thiol-yne click chemistry for the separation of basic compounds.

PubMed

Huang, Guang; Ou, Junjie; Wang, Hongwei; Ji, Yongsheng; Wan, Hao; Zhang, Zhang; Peng, Xiaojun; Zou, Hanfa

2016-04-01

A novel silica-based stationary phase with branched octadecyl groups was prepared by the sequential employment of the Michael addition reaction and photoinduced thiol-yne click chemistry with 3-aminopropyl-functionalized silica microspheres as the initial material. The resulting stationary phase denoted as SiO2 -N(C18)4 was characterized by elemental analysis, FTIR spectroscopy and Raman spectroscopy, demonstrating the existence of branched octadecyl groups in silica microspheres. The separations of benzene homologous compounds, acid compounds and amine analogues were conducted, demonstrating mixed-mode separation mechanism on SiO2 -N(C18)4 . Baseline separation of basic drugs mixture was acquired with the mobile phase of acetonitrile/H2 O (5%, v/v). SiO2 -N(C18)4 was further applied to separate Corydalis yanhusuo Wang water extracts, and more baseline separation peaks were obtained for SiO2 -N(C18)4 than those on Atlantis dC18 column. It can be expected that this new silica-based stationary phase will exhibit great potential in the analysis of basic compounds. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

ImprimatinC1, a novel plant immune-priming compound, functions as a partial agonist of salicylic acid

PubMed Central

Noutoshi, Yoshiteru; Jikumaru, Yusuke; Kamiya, Yuji; Shirasu, Ken

2012-01-01

Plant activators are agrochemicals that protect crops from pathogens. They confer durable resistance to a broad range of diseases by activating intrinsic immune mechanisms in plants. To obtain leads regarding useful compounds, we have screened a chemical library using an established method that allows selective identification of immune-priming compounds. Here, we report the characterisation of one of the isolated chemicals, imprimatinC1, and its structural derivative imprimatinC2. ImprimatinC1 functions as a weak analogue of salicylic acid (SA) and activates the expression of defence-related genes. However, it lacks antagonistic activity toward jasmonic acid. Structure-activity relationship analysis suggests that imprimatinC1 and C2 can be metabolised to 4-chlorobenzoic acid and 3,4-chlorobenzoic acid, respectively, to function in Arabidopsis. We also found that imprimatinC1 and C2 and their potential functional metabolites acted as partial agonists of SA. Thus, imprimatinC compounds could be useful tools for dissecting SA-dependent signal transduction pathways. PMID:23050089

ImprimatinC1, a novel plant immune-priming compound, functions as a partial agonist of salicylic acid.

PubMed

Noutoshi, Yoshiteru; Jikumaru, Yusuke; Kamiya, Yuji; Shirasu, Ken

2012-01-01

Plant activators are agrochemicals that protect crops from pathogens. They confer durable resistance to a broad range of diseases by activating intrinsic immune mechanisms in plants. To obtain leads regarding useful compounds, we have screened a chemical library using an established method that allows selective identification of immune-priming compounds. Here, we report the characterisation of one of the isolated chemicals, imprimatinC1, and its structural derivative imprimatinC2. ImprimatinC1 functions as a weak analogue of salicylic acid (SA) and activates the expression of defence-related genes. However, it lacks antagonistic activity toward jasmonic acid. Structure-activity relationship analysis suggests that imprimatinC1 and C2 can be metabolised to 4-chlorobenzoic acid and 3,4-chlorobenzoic acid, respectively, to function in Arabidopsis. We also found that imprimatinC1 and C2 and their potential functional metabolites acted as partial agonists of SA. Thus, imprimatinC compounds could be useful tools for dissecting SA-dependent signal transduction pathways.

Synthesis, characterization, spectroscopic properties and DFT study of a new pyridazinone family

NASA Astrophysics Data System (ADS)

Arrue, Lily; Rey, Marina; Rubilar-Hernandez, Carlos; Correa, Sebastian; Molins, Elies; Norambuena, Lorena; Zarate, Ximena; Schott, Eduardo

2017-11-01

Nitrogen compounds are widely investigated due to their pharmacological properties such as antihypertensive, antinociceptive, antibacterial, antifungal, analgesic, anticancer and inhibition activities and lately even as pesticide. In this context, we present the synthesis of new compounds: (E)-6-(3,4-dimethoxyphenyl)-3-(3-(3,4-dimethoxyphenyl)acryloyl)-1-(4-R-phenyl)- 5,6-dihydropyridazin-4(1H)-one (with R = sbnd H(1), -Cl(2), -Br(3), sbnd I(4) and sbnd COOH(5)) that was carried out by reaction of (1E, 6E)-1,7-bis(3,4-dimethoxyphenyl)hepta-1,6-diene-3,5-dione with a substituted phenylamine with general formula p-R-C6H4sbnd NH2 (R = sbnd H (1), sbnd Cl (2), -Br(3), sbnd I(4) and sbnd COOH(5)). This is the first synthesis report of a pyridazinone using as precursors a curcuminoid derivative and a diazonium salt formed in situ. All compounds were characterized by EA, FT-IR, UV-Vis, Emission,1H- and13C-NMR spectroscopy and the crystalline and molecular structure of 4 was solved by X-rays diffraction method. DFT and TD-DFT quantum chemical calculations were also employed to characterize the compounds and provide a rational explanation to the spectroscopic properties. To assess the biological activity of the systems, we focused on pesticide tests on compound 2, which showed an inhibitory effect in plant growth of Agrostis tenuis Higland.

Discovery of C-3 tethered 2-oxo-benzo[1,4]oxazines as potent antioxidants: Bio-inspired based design, synthesis, biological evaluation, cytotoxic and Insilico molecular docking studies

NASA Astrophysics Data System (ADS)

Sharma, Vashundhra; Jaiswal, Pradeep K.; Saran, Mukesh; Yadav, Dharmendra Kumar; Saloni; Mathur, Manas; Swami, Ajit K.; Misra, Sanjeev; Kim, Mi-hyun; Chaudhary, Sandeep

2018-03-01

The discovery of C-3 tethered 2-oxo-benzo[1,4]oxazines as potent antioxidants is disclosed. All the analogues 20a-20ab have been synthesized via “on water” ultrasound-assisted in excellent yields (upto 98%). All the compounds have been evaluated for their in vitro antioxidant activities using DPPH free radical scavenging assay as well as FRAP assay. The result showed promising antioxidant activities having IC50 values in the range of 4.74 ± 0.08 to 92.20 ± 1.54 μg/mL taking ascorbic acid (IC50 = 4.57 μg/mL) as standard reference. In this study, compounds 20b and 20t, the most active compound of the series, showed IC50 values of 6.89 ± 0.07μg/mL and 4.74 ± 0.08 μg/mL, respectively in comparison with ascorbic acid. In addition, the detailed SAR study shows that electron-withdrawing group increases antioxidant activity and vice versa. Furthermore, in the FRAP assay, eight compounds (20c, 20j, 20m, 20n, 20r, 20u, 20z and 20aa) were found more potent than standard reference BHT (C0.5FRAP = 546.0 ± 13.6 μM). The preliminary cytotoxic study reveals the non-toxic nature of active compounds 20b and 20t in non-cancerous 3T3 fibroblast cell lines in MTT assay up to 250 μg/mL concentration. The results were validated via carrying out insilico molecular docking studies of promising compounds 20a, 20b and 20t in comparison with standard reference. To the best of our knowledge, this is the first detailed study of C-3 tethered 2-oxo-benzo[1,4]oxazines as potential antioxidant agents.

Discovery and Validation of a New Class of Small Molecule Toll-Like Receptor 4 (TLR4) Inhibitors

PubMed Central

Neal, Matthew D.; Jia, Hongpeng; Eyer, Benjamin; Good, Misty; Guerriero, Christopher J.; Sodhi, Chhinder P.; Afrazi, Amin; Prindle, Thomas; Ma, Congrong; Branca, Maria; Ozolek, John; Brodsky, Jeffrey L.; Wipf, Peter; Hackam, David J.

2013-01-01

Many inflammatory diseases may be linked to pathologically elevated signaling via the receptor for lipopolysaccharide (LPS), toll-like receptor 4 (TLR4). There has thus been great interest in the discovery of TLR4 inhibitors as potential anti-inflammatory agents. Recently, the structure of TLR4 bound to the inhibitor E5564 was solved, raising the possibility that novel TLR4 inhibitors that target the E5564-binding domain could be designed. We utilized a similarity search algorithm in conjunction with a limited screening approach of small molecule libraries to identify compounds that bind to the E5564 site and inhibit TLR4. Our lead compound, C34, is a 2-acetamidopyranoside (MW 389) with the formula C17H27NO9, which inhibited TLR4 in enterocytes and macrophages in vitro, and reduced systemic inflammation in mouse models of endotoxemia and necrotizing enterocolitis. Molecular docking of C34 to the hydrophobic internal pocket of the TLR4 co-receptor MD-2 demonstrated a tight fit, embedding the pyran ring deep inside the pocket. Strikingly, C34 inhibited LPS signaling ex-vivo in human ileum that was resected from infants with necrotizing enterocolitis. These findings identify C34 and the β-anomeric cyclohexyl analog C35 as novel leads for small molecule TLR4 inhibitors that have potential therapeutic benefit for TLR4-mediated inflammatory diseases. PMID:23776545

Synthesis, stereochemical, structural, and biological studies of a series of N‧-(2r,4c-diaryl-3-azabicyclo[3.3.1]nonan-9-ylidene)pyrazine-2-carbohydrazides

NASA Astrophysics Data System (ADS)

Mangalam, M.; Sebastian Antony Selvan, C.; Sankar, C.

2017-02-01

A new series of N‧-(2r,4c-diaryl-3-azabicyclo[3.3.1]nonan-9-ylidene)pyrazine-2-carbohydrazides (8-14) were synthesized by the corresponding 2r,4c-diaryl-3-azabicyclo[3.3.1]nonan-9-ones (1-7) reaction with pyrazine-2-carbohydrazide. The stereochemistry of the newly synthesized compounds were unambiguously assigned using FT-IR, 1H, 13C, and 2D (COSY, HSQC, HMBC, ROESY) nuclear magnetic resonance (NMR) spectral data. The chemical shifts suggest that all these compounds adopt twin-chair conformation with equatorial orientation of aryl substitutions in solution. Hydrazones were screened for their in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv and antibacterial activity against a set of pathogenic bacteria. Most of the halogenated compounds showed promising antitubercular and antibacterial activities.

Trans-β-Caryophyllene: An Effective Antileishmanial Compound Found in Commercial Copaiba Oil (Copaifera spp.)

PubMed Central

Soares, Deivid C.; Portella, Nathalya A.; Ramos, Mônica Freiman de S.; Siani, Antonio C.; Saraiva, Elvira M.

2013-01-01

This study investigated the leishmanicidal activity against Leishmania amazonensis of four commercial oils from Copaifera spp. named as C1, C2, C3, and C4, the sesquiterpene and diterpene pools obtained from distilling C4, and isolated β-caryophyllene (CAR). Copaiba oils chemical compositions were analyzed by gas chromatography and correlated with biological activities. Diterpenes-rich oils C2 and C3 showed antipromastigote activity. Sesquiterpenes-rich C1 and C4, and isolated CAR presented a dose-dependent activity against intracellular amastigotes, with IC50s of 2.9 µg/mL, 2.3 µg/mL, and 1.3 µg/mL (6.4 µM), respectively. Based on the highest antiamastigote activity and the low toxicity to the host cells, C4 was steamdistillated to separate pools of sesquiterpenes and diterpenes. Both pools were less active against L. amazonensis and more toxic for the macrophages than the whole C4 oil. The leishmanicidal activity of C3 and C4 oils, as well as C4 fractions and CAR, appears to be independent of nitric oxide production by macrophages. This study pointed out β-caryophyllene as an effective antileishmanial compound and also to its role as potential chemical marker in copaiba oils or fractions derived thereof, aiming further development of this rainforest raw material for leishmaniasis therapy. PMID:23864897

The crystal structures of six (2E)-3-aryl-1-(5-halogeno-thio-phen-2-yl)prop-2-en-1-ones.

PubMed

Naik, Vasant S; Yathirajan, Hemmige S; Jasinski, Jerry P; Smolenski, Victoria A; Glidewell, Christopher

2015-09-01

The structures of six chalcones containing 5-halogeno-thio-phen-2-yl substituents are reported: (2E)-1-(5-chloro-thio-phen-2-yl)-3-(4-ethyl-phen-yl)prop-2-en-1-one, C15H13ClOS, (I), and (2E)-1-(5-bromo-thio-phen-2-yl)-3-(4-ethyl-phen-yl)prop-2-en-1-one, C15H13BrOS, (II), are isostructural in space group P-1, while (2E)-1-(5-chloro-thio-phen-2-yl)-3-(4-eth-oxy-phen-yl)prop-2-en-1-one, C15H13ClO2S, (III), and (2E)-1-(5-bromo-thio-phen-2-yl)-3-(4-eth-oxy-phen-yl)prop-2-en-1-one C15H13BrO2S, (IV), are isostructural in space group P21/c. There are no hydrogen bonds of any kind in the structures of compounds (I) and (II), but in the structures of compounds (III) and (IV), the mol-ecules are linked into C(7) chains by means of C-H⋯O hydrogen bonds. In the structure of (2E)-3-(4-bromo-phen-yl)-1-(5-chloro-thio-phen-2-yl)prop-2-en-1-one, C13H8BrClOS, (V), there are again no hydrogen bonds nor π-π stacking inter-actions but in that of (2E)-1-(5-bromo-thio-phen-2-yl)-3-(3-meth-oxy-phen-yl)prop-2-en-1-one, C14H11BrO2S, (VI), the mol-ecules are linked into C(5) chains by C-H⋯O hydrogen bonds. In each of compounds (I)-(VI), the mol-ecular skeletons are close to planarity, and there are short halogen⋯halogen contacts in the structures of compounds (II) and (V) and a short Br⋯O contact in the structure of compound (VI). Comparisons are made with the structures of some similar compounds.

Synthesis and anti-inflammatory activity of some benzofuran and benzopyran-4-one derivatives.

PubMed

Ragab, Fatma Abd El-Fattah; Eid, Nahed Mahmoud; Hassan, Ghaneya Sayed; Nissan, Yassin Mohammed

2012-01-01

New series of furosalicylic acids 3a-c, furosalicylanilides 6a-n, furobenzoxazines 8a-f, 1-benzofuran-3-arylprop-2-en-1-ones 12a,b, 6-(aryl-3-oxoprop-1-enyl)-4H-chromen-4-ones 16a-c and 6-[6-aryl-2-thioxo-2,5-dihydropyrimidin-4-yl]-4H-chromen-4-ones 17a-c were synthesized. Anti-inflammatory activity evaluation was performed using carrageenan-induced paw edema model in rats and prostaglandin E(2) (PGE(2)) synthesis inhibition activity. Some of the tested compounds revealed comparable activity with less ulcerogenic effect than Diclofenac at a dose 100 mg/kg. All the synthesized compounds were docked on the active site of cyclooxygenase-2 (COX-2) enzyme and most of them showed good interactions with the amino acids of the active site comparable to the interactions exhibited by Diclofenac.

Synthetic and Spectroscopic Studies on N-(i,j-Disubstituted Phenyl)-4- Substituted Benzenesulphonamides, 4-X'C6H4SO2NH(i,j-X2C6H3), where X' = H, CH3, C2H5, F, Cl or Br; i, j = 2, 3; 2, 4; 2, 5; 2, 6 or 3, 4; and X = CH3 or Cl

NASA Astrophysics Data System (ADS)

Shetty, Mahesha; Gowda, B. Thimme

2005-02-01

Fifty four N-(i,j-disubstituted phenyl)-4-substituted benzenesulphonamides of the general formula 4-X'C6H4SO2NH(i,j-X2C6H3), where X' = H, CH3, C2H5, F, Cl or Br; i,j = 2,3; 2,4; 2,5; 2,6 or 3, 4; and X = CH3 or Cl, are prepared and characterized and their infrared, 1H and 13C NMR spectra in solution are studied. The N-H stretching vibrations νN-H absorb in the range 3305 - 3205 cm-1, while the asymmetric and symmetric SO2 vibrations vary in the ranges 1377 - 1307 cm-1 and 1184 - 1128 cm-1, respectively. The N-(i,j-disubstituted phenyl)-4-substituted benzenesulphonamides show C-S, S-N and C-N stretching vibrations in the ranges 844 - 800 cm-1, 945 - 891 cm-1 and 1309 - 1170 cm-1, respectively. The compounds do not exhibit particular trends in the variation of these frequencies on substitution either at ortho or meta positions with either a methyl group or Cl. The observed 1H and 13C chemical shifts of are assigned to protons and carbon atoms of the two benzene rings. Incremental shifts of the ring protons and carbon atoms due to -SO2NH(i,j-X2C6H3) groups in C6H5SO2NH(i,j-X2C6H3) and 4-X'C6H4SO2NH- groups in 4-X'C6H4SO2NH(C6H*) are computed and employed to calculate the chemical shifts of the ring protons and carbon atoms in the substituted compounds 4-X'C6H4SO2NH(i,j-X2C6H3). The different methods of calculation lead to almost the same values in most cases and agree well with the observed chemical shifts, indicating the validity of the principle of additivity of the substituent effects with chemical shifts in these compounds.

5-deoxyflavones with cytotoxic activity from Mimosa diplotricha.

PubMed

Lin, Lie-Chwen; Chiou, Chun-Tang; Cheng, Jing-Jy

2011-09-23

Bioassay-guided isolation of Mimosa diplotricha led to the isolation of four new 5-deoxyflavones, diplotrins A-C (1-3) and diplotasin (4), together with 12 known flavonoids, flavonolignans, and triterpenoids. On the basis of spectroscopic evidence, compounds 1-4 were characterized as 2',5'-dihydroxy-3,7,8,4'-tetramethoxyflavone (1), 3'-hydroxy-3,7,8,4'-tetramethoxyflavone (2), 2'-hydroxy-7,4',5'-trimethoxyflavone (3), and 4-hydroxy-3,10,11-trimethoxyisochromeno-[4,3-b]-chromen-7(5H)-one (4). The cytotoxic effects of these isolated compounds were evaluated against the A549, AGS, HT-29, and PC3 human cancer cell lines. Compounds 2 and 5″-methoxyhydnocarpin-D (5) showed the most potent antiproliferative activity.

Crystal structures of three 1-[4-(4-bromo-but-oxy)-phen-yl] chalcone derivatives: (E)-1-[4-(4-bromo-but-oxy)-phen-yl]-3-phenyl-prop-2-en-1-one, (E)-1-[4-(4-bromo-but-oxy)-phen-yl]-3-(4-meth-oxy-phen-yl)prop-2-en-1-one and (E)-1-[4-(4-bromo-but-oxy)-phen-yl]-3-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one.

PubMed

Maragatham, Gunasekaran; Selvarani, Sivasamy; Rajakumar, Perumal; Lakshmi, Srinivasakannan

2017-07-01

The crystal structures of three chalcones with a bromo-substituted but-oxy side chain, viz . ( E )-1-[4-(4-bromo-but-oxy)-phen-yl]-3-phenyl-prop-2-en-1-one, C 19 H 19 BrO 2 , (I), ( E )-1-[4-(4-bromo-but-oxy)-phen-yl]-3-(4-meth-oxy-phen-yl)prop-2-en-1-one, C 20 H 21 BrO 3 , (II), and ( E )-1-[4-(4-bromo-but-oxy)-phen-yl]-3-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one, C 21 H 23 BrO 4 , (III), are reported. In all mol-ecules, the conformation of the keto group with respect to the olefinic bond is s - cis . Mol-ecules of (I) and (II) are nearly planar, while mol-ecule (III) is not planar. In the crystal of compounds (I) and (II), mol-ecules are linked into chains parallel to the c axis by C-H⋯π inter-actions. In the crystal of compound (III), mol-ecules are linked by a pairs of C-H⋯O hydrogen bonds, forming inversion dimers. Weak C-Br⋯π inter-actions are also observed in (III).

Novel 3D bismuth-based coordination polymers: Synthesis, structure, and second harmonic generation properties

NASA Astrophysics Data System (ADS)

Wibowo, Arief C.; Smith, Mark D.; Yeon, Jeongho; Halasyamani, P. Shiv; zur Loye, Hans-Conrad

2012-11-01

Two new 3D bismuth containing coordination polymers are reported along with their single crystal structures and SHG properties. Compound 1: Bi2O2(pydc) (pydc=pyridine-2, 5-dicarboxylate), crystallizes in the monoclinic, polar space group, P21 (a=9.6479(9) Å, b=4.2349(4) Å, c=11.9615(11) Å, β=109.587(1)°), which contains Bi2O2 chains that are connected into a 3D structure via the pydc ligands. Compound 2: Bi4Na4(1R3S-cam)8(EtOH)3.1(H2O)3.4 (1R3S cam=1R3S-camphoric acid) crystallizes in the monoclinic, polar space group, P21 (a=19.0855(7) Å, b=13.7706(5) Å, c=19.2429(7) Å, β=90.701(1)°) and is a true 3D coordination polymer. These are two example of SHG compounds prepared using unsymmetric ligands (compound 1) or chiral ligands (compound 2), together with metals that often exhibit stereochemically-active lone pairs, such as Bi3+, a synthetic approach that resulted in polar, non-centrosymmetric, 3D metal-organic coordination polymer.

Syntheses, structures, and 1H, 13C{ 1H} and 119Sn{ 1H} NMR chemical shifts of a family of trimethyltin alkoxide, amide, halide and cyclopentadienyl compounds

DOE PAGES

Lichtscheidl, Alejandro G.; Janicke, Michael T.; Scott, Brian L.; ...

2015-08-21

The synthesis and full characterization, including Nuclear Magnetic Resonance (NMR) data ( 1H, 13C{ 1H} and 119Sn{ 1H}), for a series of Me 3SnX (X = O-2,6-tBu 2C 6H 3 (1), (Me 3Sn)N(2,6- iPr 2C 6H 3) (3), NH-2,4,6- tBu 3C 6H 2 (4), N(SiMe 3) 2 (5), NEt 2, C 5Me 5 (6), Cl, Br, I, and SnMe 3) compounds in benzene-d 6, toluene-d 8, dichloromethane-d 2, chloroform-d 1, acetonitrile-d 3, and tetrahydrofuran-d 8 are reported. The X-ray crystal structures of Me 3Sn(O-2,6- tBu 2C 6H 3) (1), Me 3Sn(O-2,6- iPr 2C 6H 3) (2), and (Me 3Sn)(NH-2,4,6- tBumore » 3C 6H 2) (4) are also presented. As a result, these compiled data complement existing literature data and ease the characterization of these compounds by routine NMR experiments.« less

Crystal chemistry of thorium nitrates and chromates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sigmon, Ginger E.; Burns, Peter C., E-mail: pburns@nd.ed

2010-07-15

The structures and infrared spectra of six novel thorium compounds are reported. Th(NO{sub 3}){sub 2}(OH){sub 2}(H{sub 2}O){sub 2} (1) crystallizes in space group C2/c, a=14.050(1), b=8.992(7), c=5.954(5) A, {beta}=101.014(2){sup o}. K{sub 2}Th(NO{sub 3}){sub 6} (2), P-3, a=13.606(1), c=6.641(6) A. (C{sub 12}H{sub 28}N){sub 2}Th(NO{sub 3}){sub 6} (3), P2{sub 1}/c, a=14.643(4), b=15.772(5), c=22.316(5) A, {beta}=131.01(1){sup o}. KTh(NO{sub 3}){sub 5}(H{sub 2}O){sub 2} (4), P2{sub 1}/c, a=10.070(8), b=12.731(9), c=13.231(8) A, {beta}=128.647(4){sup o}. Th(CrO{sub 4}){sub 2}(H{sub 2}O){sub 2} (5), P2{sub 1}/n, a=12.731(1), b=9.469(8), c=12.972(1) A, {beta}=91.793(2){sup o}. K{sub 2}Th{sub 3}(CrO{sub 4}){sub 7}(H{sub 2}O){sub 10} (6), Ama2, a=19.302(8), b=15.580(6), c=11.318(6) A. The coordination polyhedra about Thmore » in these structures are diverse. Th is coordinated by 9 O atoms in 5 and 6, seven of which are from monodentate (CrO{sub 4}) tetrahedra and two are (H{sub 2}O). The Th in compound 1 is coordinated by ten O atoms, four of which are O atoms of two bidentate (NO{sub 3}) triangles and six of which are (OH) and (H{sub 2}O). In compounds 2, 3 and 4 the Th is coordinate by 12 O atoms. In 2 and 3 there are six bidentate (NO{sub 3}) triangles, and in 4 ten of the O atoms are part of five bidentate (NO{sub 3}) triangles and the others are (H{sub 2}O) groups. The structural units of these compounds consist of a chain of thorium and nitrate polyhedra (1), isolated thorium hexanitrate clusters (2, 3), an isolated thorium pentanitrate dihydrate cluster (4), and a sheet (6) and framework (5) of thorium and chromate polyhedra. These structures illustrate the complexity inherent in the crystal chemistry of Th. - Graphical Abstract: The structures and infrared spectra of four new Th nitrates and two Th chromates are reported. The coordination numbers of the Th cations range from nine to 12 in these compounds. Structural units consist of isolated clusters, chains, sheets and frameworks.« less

Synthesis and Structural Characterization of Magnesium Based Coordination Networks in Different Solvents

DOE Office of Scientific and Technical Information (OSTI.GOV)

D Banerjee; J Finkelstein; A Smirnov

2011-12-31

Three magnesium based metal-organic frameworks, Mg{sub 3}(3,5-PDC){sub 3}(DMF){sub 3} {center_dot} DMF [1], Mg(3,5-PDC)(H{sub 2}O) {center_dot} (H{sub 2}O) [3], and Mg{sub 4}(3,5-PDC){sub 4}(DMF){sub 2}(H{sub 2}O){sub 2} {center_dot} 2DMF {center_dot} 4.5H{sub 2}O [4], and a 2-D coordination polymer, [Mg(3,5-PDC)(H{sub 2}O){sub 2}] [2] [PDC = pyridinedicarboxylate], were synthesized using a combination of DMF, methanol, ethanol, and water. Compound 1 [space group P2{sub 1}/n, a = 12.3475(5) {angstrom}, b = 11.1929(5) {angstrom}, c = 28.6734(12) {angstrom}, {beta} = 98.8160(10){sup o}, V = 3916.0(3) {angstrom}{sup 3}] consists of a combination of isolated and corner-sharing magnesium octahedra connected by the organic linkers to form a 3-Dmore » network with a 12.2 {angstrom} x 4.6 {angstrom} 1-D channel. The channel contains coordinated and free DMF molecules. In compound 2 [space group C2/c, a = 9.964(5) {angstrom}, b = 12.0694(6) {angstrom}, c = 7.2763(4) {angstrom}, {beta} = 106.4970(6){sup o}, V = 836.70(6) {angstrom}{sup 3}], PDC connects isolated seven coordinated magnesium polyhedra into a layered structure. Compound 3 [space group P6{sub 1}22, a = 11.479(1) {angstrom}, c = 14.735(3) {angstrom}, V = 1681.7(4) {angstrom}{sup 3}] (previously reported) contains isolated magnesium octahedra connected by the organic linker with each other forming a 3D network. Compound 4 [space group P2{sub 1}/c, a = 13.7442(14) {angstrom}, b = 14.2887(15) {angstrom}, c = 14.1178(14) {angstrom}, {beta} = 104.912(2){sup o}, V = 2679.2(5) {angstrom}{sup 3}] also exhibits a 3D network based on isolated magnesium octahedra with square cavities containing both disordered DMF and water molecules. The structural topologies originate due to the variable coordination ability of solvent molecules with the metal center. Water molecules coordinate with the magnesium metal centers preferably over other polar solvents (DMF, methanol, ethanol) used to synthesize the coordination networks. Despite testing multiple desolvation routes, we were unable to measure BET surface areas greater than 51.9 m{sup 2}/g for compound 1.« less

Synthesis and Structural Characterization of Magnesium Based Coordination Networks in Different Solvents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banerjee, Debasis; Finkelstein, Jeffrey; Smirnov, A.

2015-10-15

Three magnesium based metal-organic frameworks, Mg{sub 3}(3,5-PDC){sub 3}(DMF){sub 3} {center_dot} DMF [1], Mg(3,5-PDC)(H{sub 2}O) {center_dot} (H{sub 2}O) [3], and Mg4(3,5-PDC)4(DMF){sub 2}(H{sub 2}O){sub 2} {center_dot} 2DMF {center_dot} 4.5H{sub 2}O [4], and a 2-D coordination polymer, [Mg(3,5-PDC)(H{sub 2}O){sub 2}] [2] [PDC = pyridinedicarboxylate], were synthesized using a combination of DMF, methanol, ethanol, and water. Compound 1 [space group P2{sub 1}/n, a = 12.3475(5) {angstrom}, b = 11.1929(5) {angstrom}, c = 28.6734(12) {angstrom}, {beta} = 98.8160(10){sup o}, V = 3916.0(3) {angstrom}{sup 3}] consists of a combination of isolated and corner-sharing magnesium octahedra connected by the organic linkers to form a 3-D network withmore » a 12.2 {angstrom} x 4.6 {angstrom} 1-D channel. The channel contains coordinated and free DMF molecules. In compound 2 [space group C2/c, a = 9.964(5) {angstrom}, b = 12.0694(6) {angstrom}, c = 7.2763(4) {angstrom}, {beta} = 106.4970(6){sup o}, V = 836.70(6) {angstrom}{sup 3}], PDC connects isolated seven coordinated magnesium polyhedra into a layered structure. Compound 3 [space group P6{sub 1}22, a = 11.479(1) {angstrom}, c = 14.735(3) {angstrom}, V = 1681.7(4) {angstrom}{sup 3}] (previously reported) contains isolated magnesium octahedra connected by the organic linker with each other forming a 3D network. Compound 4 [space group P2{sub 1}/c, a = 13.7442(14) {angstrom}, b = 14.2887(15) {angstrom}, c = 14.1178(14) {angstrom}, {beta} = 104.912(2){sup o}, V = 2679.2(5) {angstrom}{sup 3}] also exhibits a 3D network based on isolated magnesium octahedra with square cavities containing both disordered DMF and water molecules. The structural topologies originate due to the variable coordination ability of solvent molecules with the metal center. Water molecules coordinate with the magnesium metal centers preferably over other polar solvents (DMF, methanol, ethanol) used to synthesize the coordination networks. Despite testing multiple desolvation routes, we were unable to measure BET surface areas greater than 51.9 m{sup 2}/g for compound 1.« less

Effect of Sulfate on Selenium Uptake And Chemical Speciation in Convolvulus Arvensis L

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cruz-Jimenez, G.; Peralta-Video, J.R.; Rosa, G.de la

2007-08-08

Hydroponic experiments were performed to study several aspects of Se uptake by C. arvensis plants. Ten day old seedlings were exposed for eight days to different combinations of selenate (SeO{sub 4}{sup 2-}), sulfate (SO{sub 4}{sup 2-}), and selenite (SeO{sub 3}{sup 2-}). The results showed that in C. arvensis, SO{sub 4}{sup 2-} had a negative effect (P < 0.05) on SeO{sub 4}{sup 2-} uptake. However, a positive interaction produced a significant increase in SO{sub 4}{sup 2-} uptake when SeO{sub 4}{sup 2-} was at high concentration in the media. X-ray absorption spectroscopy studies showed that C. arvensis plants converted more than 70%more » of the supplied SeO{sub 3}{sup 2-} into organoselenium compounds. However, only approximately 50% of the supplied SeO{sub 4}{sup 2-} was converted into organoselenium species while the residual 50% remained in the inorganic form. Analysis using LC-XANES fittings confirmed that the S metabolic pathway was affected by the presence of Se. The main Se compounds that resembled those Se species identified in C. arvensis were Se-cystine, Se-cysteine, SeO{sub 3}{sup 2-}, and SeO{sub 4}{sup 2-}, whereas for S the main compounds were cysteine, cystine, oxidized glutathione, reduced glutathione, and SO{sub 4}{sup 2-}. The results of these studies indicated that C. arvensis could be considered as a possible option for the restoration of soil moderately contaminated with selenium even in the presence of sulfate.« less

Two Homologous Intermetallic Phases in the Na-Au-Zn System with Sodium Bound in Unusual Paired Sites within 1D Tunnels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Samal, Saroj L.; Lin, Qisheng; Corbett, John D.

The Na-Au-Zn system contains the two intermetallic phases Na(0.97(4))Au(2)Zn(4)(I) and Na(0.72(4))Au(2)Zn(2)(II) that are commensurately and incommensurately modulated derivatives of K(0.37)Cd(2), respectively. Compound I crystallizes in tetragonal space group P4/mbm (No. 127), a = 7.986(1) Å, c = 7.971(1) Å, Z = 4, as a 1 × 1 × 3 superstructure derivative of K(0.37)Cd(2)(I4/mcm). Compound II is a weakly incommensurate derivative of K(0.37)Cd(2) with a modulation vector q = 0.189(1) along c. Its structure was solved in superspace group P4/mbm(00g)00ss, a = 7.8799(6) Å, c = 2.7326(4) Å, Z = 2, as well as its average structure in P4/mbm with themore » same lattice parameters.. The Au-Zn networks in both consist of layers of gold or zinc squares that are condensed antiprismatically along c ([Au(4/2)Zn(4)Zn(4)Au(4/2)] for I and [Au(4/2)Zn(4)Au(4/2)] for II) to define fairly uniform tunnels. The long-range cation dispositions in the tunnels are all clearly and rationally defined by electron density (Fourier) mapping. These show only close, somewhat diffuse, pairs of opposed, ≤50% occupied Na sites that are centered on (I)(shown) or between (II) the gold squares. Tight-binding electronic structure calculations via linear muffin-tin-orbital (LMTO) methods, assuming random occupancy of ≤ ∼100% of nonpaired Na sites, again show that the major Hamilton bonding populations in both compounds arise from the polar heteroatomic Au-Zn interactions. Clear Na-Au (and lesser Na-Zn) bonding is also evident in the COHP functions. These two compounds are the only stable ternary phases in the (Cs,Rb,K,Na)-Au-Zn systems, emphasizing the special bonding and packing requirements in these sodium structures« less

Bluish-green BMes2-functionalized Pt(II) complexes for high efficiency PhOLEDs: impact of the BMes2 location on emission color.

PubMed

Rao, Ying-Li; Schoenmakers, Dylan; Chang, Yi-Lu; Lu, Jia-Sheng; Lu, Zheng-Hong; Kang, Youngjin; Wang, Suning

2012-09-03

New phosphorescent Pt(II) compounds based on dimesitylboron (BMes(2))-functionalized 2-phenylpyridyl (ppy) N,C-chelate ligands and an acetylacetonato ancillary ligand have been achieved. We have found that BMes(2) substitution at the 4'-position of the phenyl ring can blue-shift the phosphorescent emission energy of the Pt(II) compound by approximately 50 nm, compared to the 5'-BMes(2) substituted analogue, without substantial loss of luminescent quantum efficiencies. The emission color of the 4'-BMes(2) substituted Pt(II) compound, Pt(Bppy)(acac) (1) can be further tuned by the introduction of a substituent group at the 3'-position of the phenyl ring. A methyl substituent red-shifts the emission energy of 1 by approximately 10 nm whereas a fluoro substituent blue-shifts the emission energy by about 6 nm. Using this strategy, three bright blue-green phosphorescent Pt(II) compounds 1, 2 and 3 with emission energy at 481, 492, and 475 nm and Φ(PL)=0.43, 0.26 and 0.25, respectively, have been achieved. In addition, we have examined the impact of BMes(2) substitution on 3,5-dipyridylbenzene (dpb) N,C,N-chelate Pt(II) compounds by synthesizing compound 4, Pt(Bdpb)Cl, which has a BMes(2) group at the 4'-position of the benzene ring. Compound 4 has a phosphorescent emission band at 485 nm and Φ(PL)=0.70. Highly efficient blue-green electroluminescent (EL) devices with a double-layer structure and compounds 1, 3 or 4 as the phosphorescent dopant have been fabricated. At 100 cd m(-2) luminance, EL devices based on 1, 3 and 4 with an external quantum efficiency of 4.7, 6.5 and 13.4%, respectively, have been achieved. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A new class of pyrazolo[5,1-c][1,2,4]triazines as γ-aminobutyric type A (GABAA) receptor subtype ligand: synthesis and pharmacological evaluation.

PubMed

Guerrini, Gabriella; Ciciani, Giovanna; Daniele, Simona; Martini, Claudia; Costagli, Camilla; Guarino, Chiara; Selleri, Silvia

2018-05-15

A comparison between compounds with pyrazolo[1,5-a]pyrimidine structure (series 4-6) and pyrazolo[5,1-c][1,2,4]triazine core (series 9) as ligands at GABA A -receptor subtype, was evaluated. Moreover, for pyrazolotriazine derivatives having binding recognition, the interaction on recombinant rat α(1-3,5) GABA A receptor subtypes, was performed. Among these latter, emerge compounds 9c, 9k, 9l, 9m and 9n as α1-selective and 9h as α2-selective ligands. Copyright © 2018 Elsevier Ltd. All rights reserved.

Tautomerism in o-hydroxyanilino-1,4-naphthoquinone derivatives: Structure, NMR, HPLC and density functional theoretic investigations

NASA Astrophysics Data System (ADS)

Bhand, Sujit; Patil, Rishikesh; Shinde, Yogesh; Lande, Dipali N.; Rao, Soniya S.; Kathawate, Laxmi; Gejji, Shridhar P.; Weyhermüller, Thomas; Salunke-Gawali, Sunita

2016-11-01

Structure and spectral characteristics of 'Ortho' ((E)-4-hydroxy-2-(2‧-(4‧-R)-hydroxyphenyl)-imino)-naphthalen-1(2H)-one) and 'para' (2-(2‧-(4‧-R)-hydroxyphenyl)-amino)-1,4-naphthoquinone) tautomers of o-hydroxyanilino-1,4-naphthoquinone derivatives (Rdbnd H, 1A; sbnd CH3, 2A; and -Cl, 3A) are investigated using the 1H, 13C, DEPT, gDQCOSY, gHSQCAD NMR, HPLC, cyclic voltammetry techniques combined with the density functional theory. The compound 2A crystallizes in monoclinic space group P21/c. wherein the polymer chain is facilitated via Osbnd H⋯O and Csbnd H⋯O intermolecular hydrogen bonding. Marginal variations in bond distances in quinonoid and aminophenol moieties render structural flexibility to these compounds those in solution exist as exist in 'ortho - para' tautomers. 1H and 13C NMR spectra in DMSO-d6 showed two sets of peaks in all compounds; whereas only the para tautomer of for 1A and 2A, the para tautomer is predominant in CD3CN solution. Further the ortho-para interconversion is accompanied by a large up-field signals for C(3)sbnd H(3) in their 1H and 13C NMR spectra. These inferences are corroborated by the density functional theoretic calculations.

Microbial biotransformation of gentiopicroside by the endophytic fungus Penicillium crustosum 2T01Y01.

PubMed

Zeng, Wen-Liang; Li, Wan-Kui; Han, Han; Tao, Yan-Yan; Yang, Li; Wang, Zheng-Tao; Chen, Kai-Xian

2014-01-01

Endophytic fungi are symbiotic with plants and possess multienzyme systems showing promising metabolite potency with region selectivity and stereoselectivity. The aim of this study was to use these special microorganisms as an in vitro model to mimic the potential mammalian metabolites of a natural iridoid gentiopicroside (GPS, compound 1). The fungi isolated from a medicinal plant, Dendrobium candidum Wall. ex Lindl., were screened for their biotransformation abilities with GPS as the substrate, and one strain with high converting potency was identified as Penicillium crustosum 2T01Y01 on the basis of the sequence of the internal transcribed spacer of the ribosomal DNA region. Upon the optimized incubation of P. crustosum 2T01Y01 with the substrate, seven deglycosylated metabolites were detected by ultraperformance liquid chromatography/quadrupole time of flight mass spectrometry (UPLC/Q-TOF MS). Preparative-scale biotransformation with whole cells of the endophytic fungus resulted in the production of five metabolites, including three novel ones, 5α-(hydroxymethyl)-6β-methyl-3,4,5,6-tetrahydropyrano[3,4-c]pyran-1(8H)-one (compound 2), (Z)-4-(1-hydroxybut-3-en-2-yl)-5,6-dihydropyran-2-one (compound 3), and (E)-4-(1-hydroxybut-3-en-2-yl)-5,6-dihydropyran-2-one (compound 4), along with two known ones, 5α-(hydroxymethyl)-6β-methyl-1H,3H-5,6-dihydropyrano[3,4-c]pyran-1(3H)-one (compound 5) and 5α-(hydroxymethyl)-6α-methyl-5,6-dihydropyrano[3,4-c]pyran-1(3H)-one (compound 6), aided by nuclear magnetic resonance and high-resolution mass spectral analyses. The other two metabolites were tentatively identified by online UPLC/Q-TOF MS as 5-hydroxymethyl-5,6-dihydroisochromen-1-one (compound 7) and 5-hydroxymethyl-3,4,5,6-tetrahydroisochromen-1-one (compound 8), and compound 8 is a new metabolite. To test the metabolic mechanism, the β-glucosidase activity of the fungus P. crustosum 2T01Y01 was assayed with ρ-nitrophenyl-β-d-glucopyranoside as a probe substrate, and the pathway of GPS biotransformation by strain 2T01Y01 is proposed. In addition, the hepatoprotective activities of GPS and metabolite compounds 2, 5, and 6 against human hepatocyte line HL-7702 injury induced by hydrogen peroxide were evaluated.

Microbial Biotransformation of Gentiopicroside by the Endophytic Fungus Penicillium crustosum 2T01Y01

PubMed Central

Zeng, Wen-Liang; Li, Wan-Kui; Han, Han; Tao, Yan-Yan; Yang, Li; Chen, Kai-Xian

2014-01-01

Endophytic fungi are symbiotic with plants and possess multienzyme systems showing promising metabolite potency with region selectivity and stereoselectivity. The aim of this study was to use these special microorganisms as an in vitro model to mimic the potential mammalian metabolites of a natural iridoid gentiopicroside (GPS, compound 1). The fungi isolated from a medicinal plant, Dendrobium candidum Wall. ex Lindl., were screened for their biotransformation abilities with GPS as the substrate, and one strain with high converting potency was identified as Penicillium crustosum 2T01Y01 on the basis of the sequence of the internal transcribed spacer of the ribosomal DNA region. Upon the optimized incubation of P. crustosum 2T01Y01 with the substrate, seven deglycosylated metabolites were detected by ultraperformance liquid chromatography/quadrupole time of flight mass spectrometry (UPLC/Q-TOF MS). Preparative-scale biotransformation with whole cells of the endophytic fungus resulted in the production of five metabolites, including three novel ones, 5α-(hydroxymethyl)-6β-methyl-3,4,5,6-tetrahydropyrano[3,4-c]pyran-1(8H)-one (compound 2), (Z)-4-(1-hydroxybut-3-en-2-yl)-5,6-dihydropyran-2-one (compound 3), and (E)-4-(1-hydroxybut-3-en-2-yl)-5,6-dihydropyran-2-one (compound 4), along with two known ones, 5α-(hydroxymethyl)-6β-methyl-1H,3H-5,6-dihydropyrano[3,4-c]pyran-1(3H)-one (compound 5) and 5α-(hydroxymethyl)-6α-methyl-5,6-dihydropyrano[3,4-c]pyran-1(3H)-one (compound 6), aided by nuclear magnetic resonance and high-resolution mass spectral analyses. The other two metabolites were tentatively identified by online UPLC/Q-TOF MS as 5-hydroxymethyl-5,6-dihydroisochromen-1-one (compound 7) and 5-hydroxymethyl-3,4,5,6-tetrahydroisochromen-1-one (compound 8), and compound 8 is a new metabolite. To test the metabolic mechanism, the β-glucosidase activity of the fungus P. crustosum 2T01Y01 was assayed with ρ-nitrophenyl-β-d-glucopyranoside as a probe substrate, and the pathway of GPS biotransformation by strain 2T01Y01 is proposed. In addition, the hepatoprotective activities of GPS and metabolite compounds 2, 5, and 6 against human hepatocyte line HL-7702 injury induced by hydrogen peroxide were evaluated. PMID:24141132

The ternary system K2SO4MgSO4CaSO4

USGS Publications Warehouse

Rowe, J.J.; Morey, G.W.; Silber, C.C.

1967-01-01

Melting and subsolidus relations in the system K2SO4MgSO4CaSO4 were studied using heating-cooling curves, differential thermal analysis, optics, X-ray diffraction at room and high temperatures and by quenching techniques. Previous investigators were unable to study the binary MgSO4CaSO4 system and the adjacent area in the ternary system because of the decomposition of MgSO4 and CaSO4 at high temperatures. This problem was partly overcome by a novel sealed-tube quenching method, by hydrothermal synthesis, and by long-time heating in the solidus. As a result of this study, we found: (1) a new compound, CaSO4??3MgSO4 (m.p. 1201??C) with a field extending into the ternary system; (2) a high temperature form of MgSO4 with a sluggishly reversible inversion. An X-ray diffraction pattern for this polymorphic form is given; (3) the inversion of ??-CaSO4 (anhydrite) to ??-CaSO4 at 1195??C, in agreement with grahmann; (1) (4) the melting point of MgSO4 is 1136??C and that of CaSO4 is 1462??C (using sealed tube methods to prevent decomposition of the sulphates); (5) calcium langbeinite (K2SO4??2CaSO4) is the only compound in the K2SO4CaSO4 binary system. This resolved discrepancies in the results of previous investigators; (6) a continuous solid solution series between congruently melting K2SOP4??2MgSO4 (langbeinite) and incongruently melting K2SO4??2CaSO4 (calcium langbeinite); (7) the liquidus in the ternary system consists of primary phase fields of K2SO4, MgSO4, CaSO4, langbeinite-calcium langbeinite solid solution, and CaSO4??3MgSO4. The CaSO4 field extends over a large portion of the system. Previously reported fields for the compounds (K2SO4??MgSO4??nCaSO4), K2SO4??3CaSO4 and K2SO4??CaSO4 were not found; (8) a minimum in the ternary system at: 740??C, 25% MgSO4, 6% CaSO4, 69% K2SO4; and ternary eutectics at 882??C, 49% MgSO4, 19% CaSO4, 32% K2SO4; and 880??, 67??5% MgSO4, 5% CaSO4, 27??5% K2SO4. ?? 1967.

Microwave assisted synthesis and structure-activity relationship of 4-hydroxy-N'-[1-phenylethylidene]-2H/2-methyl-1,2-benzothiazine-3-carbohydrazide 1,1-dioxides as anti-microbial agents.

PubMed

Ahmad, Naveed; Zia-ur-Rehman, Muhammad; Siddiqui, Hamid Latif; Ullah, Muhammad Fasih; Parvez, Masood

2011-06-01

A series of 4-hydroxy-N'-[1-phenylethylidene]-2H/2-methyl, 1,2-benzothiazine-3-carbohydrazide 1,1-dioxides was synthesized from commercially available sodium saccharin. Base catalyzed ring expansion of methyl (1,1-dioxido-3-oxo-1,2-benzisothiazol-2(3H)-yl)acetate followed by ultrasound mediated hydrazinolysis and subsequent reaction with 1-phenylethanones under the influence of microwaves yielded the title compounds. Besides, microwave assisted synthesis of 1,4-dihydropyrazolo[4,3-c][1,2]benzothiazin-3-ol 5,5-dioxide and 4-methyl-1,4-dihydropyrazolo[4,3-c][1,2]benzothiazin-3-ol 5,5-dioxide is also discussed. Most of the synthesized compounds were found to possess moderate to significant anti-microbial (anti-bacterial and anti-fungal) activities. It is found that compounds with greater lipophilicity (N-methyl analogues) possessed higher anti-bacterial activities. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Mixed-Ligand Uranyl Polyrotaxanes Incorporating a Sulfate/Oxalate Coligand: Achieving Structural Diversity via pH-Dependent Competitive Effect.

PubMed

Xie, Zhen-Ni; Mei, Lei; Hu, Kong-Qiu; Xia, Liang-Shu; Chai, Zhi-Fang; Shi, Wei-Qun

2017-03-20

A mixed-ligand system provides an alternative route to tune the structures and properties of metal-organic compounds by introducing functional organic or inorganic coligands. In this work, five new uranyl-based polyrotaxane compounds incorporating a sulfate or oxalate coligand have been hydrothermally synthesized via a mixed-ligand method. Based on C6BPCA@CB6 (C6BPCA = 1,1'-(hexane-1,6-diyl)bis(4-(carbonyl)pyridin-1-ium), CB6 = cucurbit[6]uril) ligand, UPS1 (UO 2 (L) 0.5 (SO 4 )(H 2 O)·2H 2 O, L = C6BPCA@CB6) is formed by the alteration of initial aqueous solution pH to a higher acidity. The resulting 2D uranyl polyrotaxane sheet structure of UPS1 is based on uranyl-sulfate ribbons connected by the C6BPCA@CB6 pseudorotaxane linkers. By using oxalate ligand instead of sulfate, four oxalate-containing uranyl polyrotaxane compounds, UPO1-UPO4, have been acquired by tuning reaction pH and ligand concentration: UPO1 (UO 2 (L) 0.5 (C 2 O 4 ) 0.5 (NO 3 )·3H 2 O) in one-dimensional chain was obtained at a low pH value range (1.47-1.89) and UPO2 (UO 2 (L)(C 2 O 4 )(H 2 O)·7H 2 O)obtained at a higher pH value range (4.31-7.21). By lowering the amount of oxalate, another two uranyl polyrotaxane network UPO3 ((UO 2 ) 2 (L) 0.5 (C 2 O 4 ) 2 (H 2 O)) and UPO4 ((UO 2 ) 2 O(OH)(L) 0.5 (C 2 O 4 ) 0.5 (H 2 O)) could be acquired at a low pH value of 1.98 and a higher pH value over 6, respectively. The UPO1-UPO4 compounds, which display structural diversity via pH-dependent competitive effect of oxalate, represent the first series of mixed-ligand uranyl polyrotaxanes with organic ligand as the coligand. Moreover, the self-assembly process and its internal mechanism concerning pH-dependent competitive effect and other related factors such as concentration of the reagents and coordination behaviors of the coligands were discussed in detail.

An open-framework thorium sulfate hydrate with 11.5 A voids.

PubMed

Wilson, Richard E; Skanthakumar, S; Knope, Karah E; Cahill, Christopher L; Soderholm, L

2008-10-20

We report the synthesis of a thorium sulfate hydrate with 11.5 A open channels that propagate through the structure. The compound crystallizes in the tetragonal space group P4(2)/nmc, a = b = 25.890(4) A, c = 9.080(2) A, Z = 8, V = 6086.3(2) A(3). The thermal stability of the compound was investigated using thermogravimetric analysis and high-energy X-ray scattering (HEXS) revealing that the compound begins to undergo decomposition near 200 degrees C with an accompanied loss in crystallinity. The immediate coordination environment about the thorium atoms remains intact through heating to 500 degrees C as demonstrated by HEXS. Further heating reveals the formation of at least two crystalline phases, Th(SO4)2 and ThO2, which ultimately decompose to ThO2.

Further Insight into the Lability of MeCN Ligands of Cytotoxic Cycloruthenated Compounds: Evidence for the Antisymbiotic Effect Trans to the Carbon Atom at the Ru Center.

PubMed

Barbosa, Ana Soraya Lima; Werlé, Christophe; Colunga, Claudia Olivia Oliva; Rodríguez, Cecilia Franco; Toscano, Ruben Alfredo; Le Lagadec, Ronan; Pfeffer, Michel

2015-08-03

The two MeCN ligands in [Ru(2-C6H4-2'-Py-κC,N)(Phen, trans-C)(MeCN)2]PF6 (1), both trans to a sp(2) hybridized N atom, cannot be substituted by any other ligand. In contrast, the isomerized derivative [Ru(2-C6H4-2'-Py-κC,N)(Phen, cis-C)(MeCN)2]PF6 (2), in which one MeCN ligand is now trans to the C atom of the phenyl ring orthometalated to Ru, leads to fast and quantitative substitution reactions with several monodentate ligands. With PPh3, 2 affords [Ru(2-C6H4-2'-Py-κC,N)(Phen, cis-C)(PPh3)(MeCN)]PF6 (3), in which PPh3 is trans to the C σ bound to Ru. Compound 3 is not kinetically stable, because, under thermodynamic control, it leads to 4, in which the PPh3 is trans to a N atom of the Phen ligand. Dimethylsulfoxide (DMSO) can also substitute a MeCN ligand in 2, leading to 5, in which DMSO is coordinated to Ru via its S atom trans to the N atom of the Phen ligand, the isomer under thermodynamic control being the only compound observed. We also found evidence for the fast to very fast substitution of MeCN in 2 by water or a chloride anion by studying the electronic spectra of 2 in the presence of water or NBu4Cl, respectively. An isomerization related to that observed between 3 and 4 is also found for the known monophosphine derivative [Ru(2-C6H4-2'-Py-κC,N)(PPh3, trans-C)(MeCN)3]PF6 (10), in which the PPh3 is located trans to the C of the cyclometalated 2-phenylpyridine, since, upon treatment by refluxing MeCN, it leads to its isomer 11, [Ru(2-C6H4-2'-Py-κC,N)(PPh3, cis-C)(MeCN)3]PF6. Further substitutions are also observed on 11, whereby N^N chelates (N^N = 2,2'-bipyridine and phenanthroline) substitute two MeCN ligands, affording [Ru(2-C6H4-2'-Py-κC,N)(PPh3, cis-C)(N^N)(MeCN)]PF6 (12a and 12b). Altogether, the behavior of the obtained complexes by ligand substitution reactions can be rationalized by an antisymbiotic effect on the Ru center, trans to the C atom of the cyclometalated unit, leading to compounds having the least nucleophilic ligand trans to C whenever an isomerization, involving either a monodentate or a bidentate ligand, is possible.

Structures of (2E,5E)-2-(4-cyanobenzylidene)-5-(4-dimethylaminobenzylidene)cyclopentanone and (2E,5E)-2-benzylidene-5-cinnamylidenecyclopentanone

NASA Astrophysics Data System (ADS)

Zoto, Christopher A.; MacDonald, John C.

2017-10-01

The X-ray crystal structures of (2E,5E)-2-(4-cyanobenzylidene)-5-(4-dimethylaminobenzylidene)cyclopentanone (I) and (2E,5E)-2-benzylidene-5-cinnamylidenecyclopentanone (II) are presented, compared to the gas phase structures calculated using density functional theory, and discussed in the context of the photophysical behavior exhibited by I and II. Compound I crystallizes in the triclinic space group P 1 bar with a = 6.8743(2) Å, b = 8.8115(2) Å, c = 14.9664(4) Å, α = 77.135(2)°, β = 81.351(2)°, γ = 80.975(2)°, and Z = 2, and exhibits a planar structure. Compound II crystallizes in the monoclinic space group C2/c with a = 33.4281(10) Å, b = 11.9668(4) Å, c = 7.8031(2) Å, β = 92.785(2)°, and Z = 8, and adopts a nonplanar structure in the solid state and calculated structure.

Solid phase extraction of magnetic carbon doped Fe3O4 nanoparticles.

PubMed

Yang, Jing; Li, Jia-yuan; Qiao, Jun-qin; Lian, Hong-zhen; Chen, Hong-yuan

2014-01-17

Carbon decorated Fe3O4 nanoparticles (Fe3O4/C) are promising magnetic solid-phase extraction (MSPE) sorbents in environmental and biological analysis. Fe3O4/C based MSPE method shows advantages of easy operation, rapidness, high sensitivity, and environmental friendliness. In this paper, the MSPE mechanism of Fe3O4/C nanoparticles has been comprehensively investigated, for the first time, through the following three efforts: (1) the comparison of extraction efficiency for polycyclic aromatic hydrocarbons (PAHs) between the Fe3O4/C sorbents and activated carbon; (2) the chromatographic retention behaviors of hydrophobic and hydrophilic compounds on Fe3O4/C nanoparticles as stationary phase; (3) related MSPE experiments for several typical compounds such as pyrene, naphthalene, benzene, phenol, resorcinol, anisole and thioanisole. It can be concluded that there are hybrid hydrophobic interaction and hydrogen bonding interaction or dipole-dipole attraction between Fe3O4/C sorbents and analytes. It is the existence of carbon and oxygen-containing functional groups coated on the surface of Fe3O4/C nanoparticles that is responsible for the effective extraction process. Copyright © 2013 Elsevier B.V. All rights reserved.

SAR study on N2,N4-disubstituted pyrimidine-2,4-diamines as effective CDK2/CDK9 inhibitors and antiproliferative agents† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c8ra01440j

PubMed Central

Jing, Liandong; Tang, Yanbo; Goto, Masuo; Lee, Kuo-Hsiung

2018-01-01

Cyclin-dependent kinases (CDKs) are pivotal kinases in cell cycle transition and gene transcription. A series of N2,N4-diphenylpyrimidine-2,4-diamines were previously identified as potent CDK2/CDK9 inhibitors. To explore the SAR of this structural prototype, twenty-four novel N2,N4-disubstituted pyrimidine-2,4-diamines were designed and synthesized. Among them, twenty-one compounds exhibited potent inhibitory activities against both CDK2/cyclin A and CDK9/cyclin T1 systems, and the most potent CDK2 and CDK9 inhibitors, 3g and 3c, showed IC50 values of 83 nM and 65 nM respectively. Most of these compounds displayed significant inhibition against the tested tumor cell lines in the SRB assay, and in particular, remained active against the triple-negative breast cancer (TNBC) cell line MDA-MB-231. Flow cytometer analysis of compounds 2a, 2d and 3b in MDA-MB-231 cells indicated that these compounds induced cell cycle arrest in G2/M phase. Docking studies on compound 3g were performed, which provided conducive clues for further molecular optimization. PMID:29682280

Cardanols, long chain cyclohexenones and cyclohexenols from Lannea schimperi (Anacardiaceae).

PubMed

Okoth, Dorothy A; Koorbanally, Neil A

2015-01-01

Alkenyl cyclohexenones (1a-d), alkenyl cyclohexenols (2a-c and 3b-d) and cardanols (4a-d) were isolated from the stem bark and root of Lannea schimperi. The alkenyl cyclohexenones (1a and 1d) and cardanols (4a and 4d) have side chains which have not been reported previously, in combination with the core skeletal structures. In addition, compounds 2a-c and 3b-d are all new cyclohexenols. Also isolated were the triterpenes, taraxerone and taraxerol, and sitosterol. The suite of compounds isolated (cyclohexenones and cyclohexenols) make up a nice biosynthetic pathway to the cardanols. The 5-[alkenyl]-4,5- dihydroxycyclohex-2-enone mixture (1a-d) exhibited good in vitro cytotoxicity against the Chinese Hamster Ovarian mammalian cell-line. The compounds were identified mainly from GCMS and NMR spectroscopic techniques.

High temperature compounds for turbine vanes

NASA Technical Reports Server (NTRS)

Rhodes, W. H.; Cannon, R. M., Jr.

1972-01-01

Fabrication and microstructure control studies were conducted on SiC, Si3N4, and composites based on these compounds. Charpy mode impact testing to 2400 F established that beta-spodumene, lithium aluminum silicate, coated Si3N4, Si3N4 derived from alpha-Si3N4 powder, and SiC containing 5-25 v/o chopped C fibers had the most promising strengths. Several other composite systems had excellent microstructures and could prove interesting materials in the future. Stress-rupture testing on Si3N4 established that increasing 2000 F - 100 hour strengths were obtained for increasing grain size to at least 5 micrometers, increasing density and possibly increasing phase purity. These parameters became less important at 2400 F where it is thought a grain boundary phase controls strength.

The crystal structures of Ni{sub 3+x}Sn{sub 4}Zn and Ni{sub 6+x}Sn{sub 8}Zn and their structural relations to Ni{sub 3+x}Sn{sub 4}, NiSn and Ni{sub 5−δ}ZnSn{sub 4}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmetterer, Clemens, E-mail: clemens.schmetterer@univie.ac.at; Effenberger, Herta Silvia; Rajamohan, Divakar

2016-06-15

The crystal structures of two new compounds were determined from single-crystal X-ray diffraction measurements: Ni{sub 3+x}Sn{sub 4}Zn, (x~1.35, a=7.110(2) Å, b=4.123(1) Å, c=10.346(3) Å, β=90.23(2)°, space group I2/m, Z=2. R1=0.025, wR2=0.059 for 748 unique reflections, 35 variable parameters) and Ni{sub 6+x}Sn{sub 8}Zn, x~1.35 (a=12.379(3) Å, b=4.095(1) Å, c=12.155(3) Å, β=116.25(3)°, space group C2/m, Z=2. R1=0.026, wR2=0.052 for 1346 unique reflections, 60 variable parameters). In addition, a structural refinement was performed for Ni{sub 3+x}Sn{sub 4}, x~0.13 (a=12.264(3) Å, b=4.066(1) Å, c=5.223(2) Å, β=104.85(3)°, space group C2/m, Z=2. R1=0.019, wR2=0.046 for 617 unique reflections, 29 variable parameters). The three compounds show pronouncedmore » similarities among each other as well as to the crystal structures of surrounding binary Ni–Sn and ternary Ni–Sn–Zn compounds. In particular, the two new compounds form a homologous series with Ni{sub 3+x}Sn{sub 4}, x~0.13. They contain “Ni{sub 4}Sn{sub 4}” and “Ni{sub 2}Sn{sub 4}” building blocks which by different interconnection build up the distinct structures. Topological relations with NiSn and Ni{sub 5−δ}Sn{sub 4}Zn, δ~0.25 are evident. - Graphical abstract: Projection of the structure of Ni{sub 6+x}ZnSn{sub 8}, x~1.35 and constituent building blocks. Display Omitted - Highlights: • The crystal structures of Ni{sub 6+x}Sn{sub 8}Zn and Ni{sub 3+x}Sn{sub 4}Zn were determined using single crystal XRD. • Topological relations to Ni–Sn and Ni–Sn–Zn compounds were established and discussed. • Common structural units were identified and their interconnection patterns described.« less

Synthesis, structural, conformational and pharmacological study of some amides derived from 3 -methyl-2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9α-amine

NASA Astrophysics Data System (ADS)

Iriepa, I.; Bellanato, J.; Gálvez, E.; Gil-Alberdi, B.

2010-07-01

Some mono-substituted amides ( 2- 5) derived from 3-methyl-2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9α-amine were synthesized and studied by IR, 1H and 13C NMR spectroscopy. The crystal structure of 3-methyl-2,4-diphenyl-9α-(3,5-dichlorobenzamido)-3-azabicyclo[3.3.1]nonane ( 3) was determined by X-ray diffraction. NMR data showed that all compounds adopt in CDCl 3 a preferred flattened chair-chair conformation with the N-CH 3 group in equatorial disposition. X-ray data agreed with this conformation in the case of compound 3. IR data revealed that compounds 2 and 3 present a C dbnd O⋯HN intermolecular bond in the solid state. This conclusion was also confirmed by X-ray data of compound 3. In the case of compound 5, IR results suggested intermolecular NH⋯N-heterocyclic bonding. On the contrary, in the pyrazine derivative ( 4), IR, 1H and 13C NMR data showed the presence of an intramolecular NH⋯N1″-heterocyclic hydrogen bond in the solid state and solution. Moreover, NMR and IR data showed a preferred trans disposition for the NH-C dbnd O group. NMR also revealed free rotation of the -NH-CO-R group around C9-NH bond. Pharmacological assays on mice were drawn to evaluate analgesic activity.

Methanol ice VUV photoprocessing: GC-MS analysis of volatile organic compounds

NASA Astrophysics Data System (ADS)

Abou Mrad, Ninette; Duvernay, Fabrice; Chiavassa, Thierry; Danger, Grégoire

2016-05-01

Next to water, methanol is one of the most abundant molecules in astrophysical ices. A new experimental approach is presented here for the direct monitoring via gas chromatography coupled to mass spectrometry (GC-MS) of a sublimating photoprocessed pure methanol ice. Unprecedentedly, in a same analysis, compelling evidences for the formation of 33 volatile organic compounds are provided. The latter are C1-C6 products including alcohols, aldehydes, ketones, esters, ethers and carboxylic acids. Few C3 and all C4 detected compounds have been identified for the first time. Tentative detections of few C5 and C6 compounds are also presented. GC-MS allows for the first time the direct quantification of C2-C4 photoproducts and shows that their abundances decrease with the increase of their carbon chain length. These qualitative and quantitative measurements provide important complementary results to previous experiments, and present interesting similarities with observations of sources rich in methanol.

Synthesis of Polyheteroaromatic Compounds via Rhodium-Catalyzed Multiple C-H Bond Activation and Oxidative Annulation.

PubMed

Peng, Shiyong; Liu, Suna; Zhang, Sai; Cao, Shengyu; Sun, Jiangtao

2015-10-16

Polyheteroaromatic compounds are potential optoelectronic conjugated materials due to their electro- and photochemical properties. Transition-metal-catalyzed multiple C-H activation and sequential oxidative annulation allows rapidly assembling of those compounds from readily available starting materials. A rhodium-catalyzed cascade oxidative annulation of β-enamino esters or 4-aminocoumarins with internal alkynes is described to access those compounds, featuring multiple C-H/N-H bond cleavages and sequential C-C/C-N bond formations in one pot.

Iridoids and sesquiterpenoids from the roots of Valeriana officinalis.

PubMed

Wang, Peng-Cheng; Hu, Jiang-Miao; Ran, Xin-Hui; Chen, Zhong-Quan; Jiang, He-Zhong; Liu, Yu-Qing; Zhou, Jun; Zhao, You-Xing

2009-09-01

Two new iridoids, volvaltrates A and B (1 and 2), and three new sesquiterpenoids, E-(-)-3beta,4beta-epoxyvalerenal (3), E-(-)-3beta,4beta-epoxyvalerenyl acetate (4), and mononorvalerenone (5), together with five known iridoids and two known sesquiterpenoids were isolated from the roots of Valeriana officinalis. The structures and relative configurations of 1-5 were elucidated by spectroscopic evidence. Compound 1 was an unusual iridoid with an oxygen bridge connecting C-3 and C-10, forming a cage-like structure, and compound 5 was a mononorsesquiterpenoid.

Synthesis, characterization, stereochemistry and biological investigation of certain N-dichloroacetyl-bis(2-chlorophenyl)piperidin-4-ones

NASA Astrophysics Data System (ADS)

Kayalvizhi, R.; Ponnuswamy, S.; Gomathi, K.; Ezhilarasi, K. S.; Usha, G.

2018-02-01

A new series of N-dichloroacetyl-bis(2-chlorophenyl)piperidin-4-ones 4-6 has been synthesized and characterized using IR, 1H, 13C, DEPT and 2D (COSY and HSQC) NMR spectral techniques. The NMR spectral data indicate that the N-acylpiperidin-4-ones 4-6 prefer to exist in an equilibrium between the twist boat conformations with coplanar orientation of Nsbnd Cdbnd O moiety. Furthermore, the antibacterial and antifungal studies have been carried out for compounds 1-6 and the results show that they possess significant activity towards the bacterial organisms Staphylococcus aureus and Salmoneela paratyphi and better activity against the remaining bacterial organisms. All the compounds 1-6 possess moderate antifungal activity. The compounds 4-6 have been docked with the structure of MRSA and the results demonstrate that the compounds 4-6 have similar docking score and glide energy when compared to each other and thus having equal binding affinity. The antioxidant studies show greater activity for compound 4 and poor activity for compounds 5 &6 when compared to the standard drug.

Constituents of the leaves of Magnolia ovata.

PubMed

Barros, Letícia Ferrari L; Barison, Andersson; Salvador, Marcos José; de Mello-Silva, Renato; Cabral, Elaine C; Eberlin, Marcos N; Stefanello, Maria Elida A

2009-08-01

Two new lignans, magnovatins A (1) and B (2), along with nine known compounds, were isolated from the leaves of Magnolia ovata. The known compounds were identified as acuminatin (3), licarin A (4), kadsurenin M, 4-O-demethylkadsurenin M, oleiferin A, oleiferin C, spathulenol, parthenolide, and 11,13-dehydrocompressanolide. In addition, compounds 1 and 2 yielded four new derivatives (1a, 1b, 2a, and 2b). The structures of the new compounds were established on the basis of spectrometric data evaluation. Free-radical scavenging and antimicrobial activities of the major compunds 1, 3, and 4 were investigated.

Cyclic guanidines: synthesis and antiplatelet activity of 4,6,7,8-tetrahydro-1H-imidazo[1,2-a]pyrazolo[3,4-d]pyrimidin-7-ones and 1,4,6,7,8,9-hexahydropyrazolo [3',4':4,5]pyrimido[2,1-c] [1,2,4]triazin-7-ones.

PubMed

Ferroni, R; Simoni, D; Orlandini, P; Bardi, A; Franze, G P; Guarneri, M

1990-12-01

A series of 4,6,7,8-tetrahydro-1H-imidazo[1,2-a]pyrazolo [3,4-d]pyrimidin-7-ones (1b-n) and 1,4,6,7,8,9-hexahydropyrazolo [3',4':4,5]pyrimido [2,1-c][1,2,4]triazin-7-ones (2a-d) has been synthesized. In view of their potential anti-aggregating activity the compounds were tested in vitro for inhibitory activity towards ADP- and collagen-induced aggregation of human platelets. Among the compounds studied, 8-benzyl-1-(2,5-dichlorophenyl)-4,6,7,8-tetrahydro-1H-imidazo [1,2-a]pyrazolo[3,4-d]pyrimidin-7-one (1n) exhibited the most favorable activity. The 2,5-dichlorophenyl side chain is an important lipophilic and/or steric pharmacophore.

Synthesis and Biological Evaluation of 2-Methyl-4,5-Disubstituted Oxazoles as a Novel Class of Highly Potent Antitubulin Agents

PubMed Central

Romagnoli, Romeo; Baraldi, Pier Giovanni; Prencipe, Filippo; Oliva, Paola; Baraldi, Stefania; Salvador, Maria Kimatrai; Lopez-Cara, Luisa Carlota; Brancale, Andrea; Ferla, Salvatore; Hamel, Ernest; Ronca, Roberto; Bortolozzi, Roberta; Mariotto, Elena; Porcù, Elena; Basso, Giuseppe; Viola, Giampietro

2017-01-01

Antimitotic agents that interfere with microtubule formation are one of the major classes of cytotoxic drugs for cancer treatment. Multiple 2-methyl-4-(3′,4′,5′-trimethoxyphenyl)-5-substituted oxazoles and their related 4-substituted-5-(3′,4′,5′-trimethoxyphenyl) regioisomeric derivatives designed as cis-constrained combretastatin A-4 (CA-4) analogues were synthesized and evaluated for their antiproliferative activity in vitro against a panel of cancer cell lines and, for selected highly active compounds, interaction with tubulin, cell cycle effects and in vivo potency. Both these series of compounds were characterized by the presence of a common 3′,4′,5′-trimethoxyphenyl ring at either the C-4 or C-5 position of the 2-methyloxazole ring. Compounds 4g and 4i, bearing a m-fluoro-p-methoxyphenyl or p-ethoxyphenyl moiety at the 5-position of 2-methyloxazole nucleus, respectively, exhibited the greatest antiproliferative activity, with IC50 values of 0.35-4.6 nM (4g) and 0.5–20.2 nM (4i), which are similar to those obtained with CA-4. These compounds bound to the colchicine site of tubulin and inhibited tubulin polymerization at submicromolar concentrations. Furthermore, 4i strongly induced apoptosis that follows the mitochondrial pathway. In vivo, 4i in a mouse syngeneic model demonstrated high antitumor activity which significantly reduced the tumor mass at doses ten times lower than that required for CA-4P, suggesting that 4i warrants further evaluation as a potential anticancer drug. PMID:28406191

New structure type in the mixed-valent compound YbCu4Ga8.

PubMed

Subbarao, Udumula; Gutmann, Matthias J; Peter, Sebastian C

2013-02-18

The new compound YbCu(4)Ga(8) was obtained as large single crystals in high yield from reactions run in liquid gallium. Preliminary investigations suggest that YbCu(4)Ga(8) crystallizes in the CeMn(4)Al(8) structure type, tetragonal space group I4/mmm, and lattice constants are a = b = 8.6529(4) Å and c = 5.3976(11) Å. However, a detailed single-crystal XRD revealed a tripling of the c axis and crystallizing in a new structure type with lattice constants of a = b = 8.6529(4) Å and c = 15.465(1) Å. The structural model was further confirmed by neutron diffraction measurements on high-quality single crystal. The crystal structure of YbCu(4)Ga(8) is composed of pseudo-Frank-Kasper cages occupying one ytterbium atom in each ring which are shared through the corner along the ab plane, resulting in a three-dimensional network. The magnetic susceptibility of YbCu(4)Ga(8) investigated in the temperature range 2-300 K showed Curie-Weiss law behavior above 100 K, and the experimentally measured magnetic moment indicates mixed-valent ytterbium. Electrical resistivity measurements show the metallic nature of the compound. At low temperatures, variation of ρ as a function of T indicates a possible Fermi-liquid state at low temperatures.

Crystal structure of the heptamolybdate(VI) (paramolybdate) ion, [Mo7O24]6-, in the ammonium and potassium tetrahydrate salts

USGS Publications Warehouse

Evans, H.T.; Gatehouse, B.M.; Leverett, P.

1975-01-01

The crystal structures of the isomorphous salts MI6 [Mo7O24],4H2O (M = NH4 or K) have been refined by three-dimensional X-ray diffraction methods. Unit cell dimensions of these monoclinic compounds, space group P21/C with Z = 4, are, ammonium salt: a = 8.3934 ?? 0.0008, b = 36.1703 ?? 0.0045, c = 10.4715 ?? 0.0011 A??, ?? = 115.958?? ?? 0.008??; and potassium salt: a = 8.15 ?? 0.02, b = 35.68 ?? 0.1, c = 10.30 ?? 0.02 A??, ?? = 115.2?? ?? 02??. By use of multiple Weissenberg patterns, 8197 intensity data (Mo-K?? radiation) for the ammonium compound and 2178 (Cu-K?? radiation) for the potassium compound were estimated visually and used to test and refine Lindqvist's proposed structure in the space group P21/c. Lindqvist's structure was confirmed and the full matrix least-squares isotropic refinement led to R 0.076 (ammonium) 0.120 (potassium), with direct unambiguous location of the cations and water molecules in the potassium compound.

Pseudonocardians A–C, New Diazaanthraquinone Derivatives from a Deap-Sea Actinomycete Pseudonocardia sp. SCSIO 01299

PubMed Central

Li, Sumei; Tian, Xinpeng; Niu, Siwen; Zhang, Wenjun; Chen, Yuchan; Zhang, Haibo; Yang, Xianwen; Zhang, Weimin; Li, Wenjun; Zhang, Si; Ju, Jianhua; Zhang, Changsheng

2011-01-01

Pseudonocardians A–C (2–4), three new diazaanthraquinone derivatives, along with a previously synthesized compound deoxynyboquinone (1), were produced by the strain SCSIO 01299, a marine actinomycete member of the genus Pseudonocardia, isolated from deep-sea sediment of the South China Sea. The structures of compounds 1–4 were determined by mass spectrometry and NMR experiments (1H, 13C, HSQC, and HMBC). The structure of compound 1, which was obtained for the first time from a natural source, was confirmed by X-ray analysis. Compounds 1–3 exhibited potent cytotoxic activities against three tumor cell lines of SF-268, MCF-7 and NCI-H460 with IC50 values between 0.01 and 0.21 μm, and also showed antibacterial activities on Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212 and Bacillus thuringensis SCSIO BT01, with MIC values of 1–4 μg mL−1. PMID:21892356

Synthesis, stereochemistry, crystal structure, docking study and biological evaluation of some new N-benzylpiperidin-4-ones

NASA Astrophysics Data System (ADS)

Ponnuswamy, S.; Kayalvizhi, R.; Sethuvasan, S.; Sugumar, P.; Ponnuswamy, M. N.

2018-03-01

Two new N-benzylpiperidin-4-ones 3 and 4 have been synthesized and characterized using IR, 1D and 2D NMR spectral studies. The NMR data of N-benzylpiperidin-4-ones 3 and 4 reveal that the compounds prefer to exist in chair conformation with equatorial orientation of the bulky substituents and the single crystal X-ray structure of compound 4 also reveals a similar conformation in solid state. Furthermore, the antimicrobial studies carried out for the compounds 1-4 indicate moderate activities with the selected strains. The antioxidant potency of 3 is superior whereas 4 exhibits moderate activity when compared to that of standard drug. The results of molecular docking studies with the AmpC β-lactamase enzyme indicate that compound 3 shows better docking score and binding energy than the co-crystal ligand.

Quantum mechanical and spectroscopic (FT-IR, 13C, 1H NMR and UV) investigations of 2-(5-(4-Chlorophenyl)-3-(pyridin-2-yl)-4,5-dihydropyrazol-1-yl)benzo[d]thiazole by DFT method

NASA Astrophysics Data System (ADS)

Diwaker

2014-07-01

The electronic, NMR, vibrational, structural properties of a new pyrazoline derivative: 2-(5-(4-Chlorophenyl)-3-(pyridine-2-yl)-4,5-dihydropyrazol-1-yl)benzo[d]thiazole has been studied using Gaussian 09 software package. Using VEDA 4 program we have reported the PED potential energy distribution of normal mode of vibrations of the title compound. We have also reported the 1H and 13C NMR chemical shifts of the title compound using B3LYP level of theory with 6-311++G(2d,2p) basis set. Using time dependent (TD-DFT) approach electronic properties such as HOMO and LUMO energies, electronic spectrum of the title compound has been studied and reported. NBO analysis and MEP surface mapping has also been calculated and reported using ab initio methods.

The Inhibition of Aluminum Corrosion in Sulfuric Acid by Poly(1-vinyl-3-alkyl-imidazolium Hexafluorophosphate)

PubMed Central

Arellanes-Lozada, Paulina; Olivares-Xometl, Octavio; Guzmán-Lucero, Diego; Likhanova, Natalya V.; Domínguez-Aguilar, Marco A.; Lijanova, Irina V.; Arce-Estrada, Elsa

2014-01-01

Compounds of poly(ionic liquid)s (PILs), derived from imidazole with different alkylic chain lengths located in the third position of the imidazolium ring (poly(1-vinyl-3-dodecyl-imidazolium) (PImC12), poly(1-vinyl-3-octylimidazolium) (PImC8) and poly(1-vinyl-3-butylimidazolium) (PImC4) hexafluorophosphate) were synthesized. These compounds were tested as corrosion inhibitors on aluminum alloy AA6061 in diluted sulfuric acid (0.1–1 M H2SO4) by weight loss tests, polarization resistance measurements and inductively coupled plasma optical emission spectroscopy. Langmuir’s isotherms suggested film formation on bare alloy while standard free energy indicated inhibition by a physisorption process. However, compound efficiencies as inhibitors ranked low (PImC12 > PImC8 > PImC4) to reach 61% for PImC12 in highly diluted acidic solution. Apparently, the high mobility of sulfates favored their adsorption in comparison to PILs. The surface film displayed general corrosion, and pitting occurred as a consequence of PILs’ partial inhibition along with a continuous dissolution of defective patchy film on formation. A slight improvement in efficiency was displayed by compounds having high molecular weight and a long alkyl chain, as a consequence of steric hindrance and PIL interactions. PMID:28788156

Synthesis, Characterization, and Anti-Cancer Activity of Some New N'-(2-Oxoindolin-3-ylidene)-2-propylpentane hydrazide-hydrazones Derivatives.

PubMed

El-Faham, Ayman; Farooq, Muhammad; Khattab, Sherine N; Abutaha, Nael; Wadaan, Mohammad A; Ghabbour, Hazem A; Fun, Hoong-Kun

2015-08-13

Eight novel N'-(2-oxoindolin-3-ylidene)-2-propylpentane hydrazide-hydrazone derivatives 4a-h were synthesized and fully characterized by IR, NMR ((1)H-NMR and (13)C-NMR), elemental analysis, and X-ray crystallography. The cyto-toxicity and in vitro anti-cancer evaluation of the prepared compounds have been assessed against two different human tumour cell lines including human liver (HepG2) and leukaemia (Jurkat), as well as in normal cell lines derived from human embryonic kidney (HEK293) using MTT assay. The compounds 3e, 3f, 4a, 4c, and 4e revealed promising anti-cancer activities in tested human tumour cells lines (IC50 values between 3 and 7 μM) as compared to the known anti-cancer drug 5-Fluorouracil (IC50 32-50 μM). Among the tested compounds, 4a showed specificity against leukaemia (Jurkat) cells, with an IC50 value of 3.14 μM, but this compound was inactive in liver cancer and normal cell lines.

4'-alpha-C-Branched N,O-nucleosides: synthesis and biological properties.

PubMed

Chiacchio, Ugo; Genovese, Filippo; Iannazzo, Daniela; Piperno, Anna; Quadrelli, Paolo; Antonino, Corsaro; Romeo, Roberto; Valveri, Vincenza; Mastino, Antonio

2004-07-15

The synthesis of 4'-alpha-C-branched N,O-nucleosides has been described, based on the 1,3-dipolar cycloaddition of nitrones with vinyl acetate followed by coupling with silylated nucleobases, The obtained compounds have been evaluated for their activity against HSV-1, HSV-2, HTLV-1. Cytotoxicity and apoptotic activity have been also investigated: compound 10c shows moderate apoptotic activity in Molt-3 cells.

Synthesis of three novel fluorine-18 labeled analogues of L-deprenyl for positron emission tomography (PET) studies of monoamine oxidase B (MAO-B).

PubMed

Nag, Sangram; Lehmann, Lutz; Heinrich, Tobias; Thiele, Andrea; Kettschau, Georg; Nakao, Ryuji; Gulyás, Balázs; Halldin, Christer

2011-10-27

The aim in this project was to synthesize and to study fluorine-18 labeled analogues of l-deprenyl which bind selectively to the enzyme monoamine oxidase B (MAO-B). Three fluorinated l-deprenyl analogues have been generated in multistep organic syntheses. The most promising fluorine-18 compound N-[(2S)-1-[(18)F]fluoro-3-phenylpropan-2-yl]-N-methylprop-2-yn-1-amine (4c) was synthesized by a one-step fluorine-18 nucleophilic substitution reaction. Autoradiography on human brain tissue sections demonstrated specific binding for compound 4c to brain regions known to have a high content of MAO-B. In addition, the corresponding nonradioactive fluorine-19 compound (13) inhibited recombinant human MAO-B with an IC(50) of 170.5 ± 29 nM but did not inhibit recombinant human MAO-A (IC(50) > 2000 nM), demonstrating its specificity. Biodistribution of 4c in mice showed high initial brain uptake leveling at 5.2 ± 0.04%ID/g after 2 min post injection. In conclusion, compound 4c is a specific inhibitor of MAO-B with high initial brain uptake in mice and is, therefore, a candidate for further investigation in PET.

Phenolic constituents from the root bark of Morus alba L. and their cardioprotective activity in vitro.

PubMed

Zheng, Xiao-Ke; Cao, Yan-Gang; Ke, Ying-Ying; Zhang, Yan-Li; Li, Fang; Gong, Jian-Hong; Zhao, Xuan; Kuang, Hai-Xue; Feng, Wei-Sheng

2017-03-01

A flavanone C-glycoside, steppogenin-5'-C-β-D-glucopyranoside, six prenylated 2-arylbenzofuran derivatives, moracin O-3″-O-β-D-glucopyranoside, moracin O-3'-O-β-D-xylopyranoside, moracin P-2″-O-β-D-glucopyranoside, moracin P-3'-O-β-D-glucopyranoside, moracin P-3'-O-α-L-arabinopyranoside and moracin P-3'-O-[β-D-glucopyranosyl-(1 → 2)]-α-L-arabinopyranoside, two phenolic acids, 2,4-dihydroxy-5-(4-hydroxybenzyl) benzoic acid and 2,4-dihydroxy-5-(3,4-dihydroxybenzyl) benzoic acid, as well as three known compounds, moracinoside C, moracin O, and moracin P were isolated from the root bark of Morus alba L. Their structures were ascertained on the basis of spectroscopic evidence. The protective effects of the compounds against doxorubicin-induced cardiomyopathy in H9c2 cells was investigated in vitro. Of all of the isolated compounds, moracin P-3'-O-β-D-glucopyranoside, moracin O and moracin P had a strong protective influence against doxorubicin-induced cell death with EC 50 values of 9.5 ± 2.6, 4.5 ± 1.3, and 8.8 ± 2.4 μM, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Molecular Structures, Vibrational Spectroscopy, and Normal-Mode Analysis of M(2)(C&tbd1;CR)(4)(PMe(3))(4) Dimetallatetraynes. Observation of Strongly Mixed Metal-Metal and Metal-Ligand Vibrational Modes.

PubMed

John, Kevin D.; Miskowski, Vincent M.; Vance, Michael A.; Dallinger, Richard F.; Wang, Louis C.; Geib, Steven J.; Hopkins, Michael D.

1998-12-28

The nature of the skeletal vibrational modes of complexes of the type M(2)(C&tbd1;CR)(4)(PMe(3))(4) (M = Mo, W; R = H, Me, Bu(t)(), SiMe(3)) has been deduced. Metrical data from X-ray crystallographic studies of Mo(2)(C&tbd1;CR)(4)(PMe(3))(4) (R = Me, Bu(t)(), SiMe(3)) and W(2)(C&tbd1;CMe)(4)(PMe(3))(4) reveal that the core bond distances and angles are within normal ranges and do not differ in a statistically significant way as a function of the alkynyl substituent, indicating that their associated force constants should be similarly invariant among these compounds. The crystal structures of Mo(2)(C&tbd1;CSiMe(3))(4)(PMe(3))(4) and Mo(2)(C&tbd1;CBu(t)())(4)(PMe(3))(4) are complicated by 3-fold disorder of the Mo(2) unit within apparently ordered ligand arrays. Resonance-Raman spectra ((1)(delta-->delta) excitation, THF solution) of Mo(2)(C&tbd1;CSiMe(3))(4)(PMe(3))(4) and its isotopomers (PMe(3)-d(9), C&tbd1;CSiMe(3)-d(9), (13)C&tbd1;(13)CSiMe(3)) exhibit resonance-enhanced bands due to a(1)-symmetry fundamentals (nu(a) = 362, nu(b) = 397, nu(c) = 254 cm(-)(1) for the natural-abundance complex) and their overtones and combinations. The frequencies and relative intensities of the fundamentals are highly sensitive to isotopic substitution of the C&tbd1;CSiMe(3) ligands, but are insensitive to deuteration of the PMe(3) ligands. Nonresonance-Raman spectra (FT-Raman, 1064 nm excitation, crystalline samples) for the Mo(2)(C&tbd1;CSiMe(3))(4)(PMe(3))(4) compounds and for Mo(2)(C&tbd1;CR)(4)(PMe(3))(4) (R = H, D, Me, Bu(t)(), SiMe(3)) and W(2)(C&tbd1;CMe)(4)(PMe(3))(4) exhibit nu(a), nu(b), and nu(c) and numerous bands due to alkynyl- and phosphine-localized modes, the latter of which are assigned by comparisons to FT-Raman spectra of Mo(2)X(4)L(4) (X = Cl, Br, I; L = PMe(3), PMe(3)-d(9))(4) and Mo(2)Cl(4)(AsMe(3))(4). Valence force-field normal-coordinate calculations on the model compound Mo(2)(C&tbd1;CH)(4)P(4), using core force constants transferred from a calculation on Mo(2)Cl(4)P(4), show that nu(a), nu(b), and nu(c) arise from modes of strongly mixed nu(Mo(2)), nu(MoC), and lambda(MoCC) character. The relative intensities of the resonance-Raman bands due to nu(a), nu(b), and nu(c) reflect, at least in part, their nu(M(2)) character. In contrast, the force field shows that mixing of nu(M(2)) and nu(C&tbd1;C) is negligible. The three-mode mixing is expected to be a general feature for quadruply bonded complexes with unsaturated ligands.

A structural and vibrational study on the first condensed borosulfate K5[B(SO4)4] by using the FTIR-Raman spectra and DFT calculations

NASA Astrophysics Data System (ADS)

Höppe, Henning Alfred; Kazmierczak, Karolina; Romano, Elida; Brandán, Silvia Antonia

2013-04-01

The first borosulfate, K5[B(SO4)4] (recently synthesized by Henning A. Höppe, Karolina Kazmierczak, Michael Daub, Katharina Förg, Franziska Fuchs, Harald Hillebrecht, 2012) was characterized by infrared and Raman spectroscopies. Density functional theory (DFT) calculations were used to study the structure and vibrational properties of the compound. Employing the B3P86 and B3LYP levels of theory, the molecular structures of the compound were theoretically determined in gas phase and the harmonic vibrational frequencies were evaluated at the same levels. The calculated harmonic vibrational frequencies for the borosulfate compound are consistent with the experimental IR and Raman spectra. These calculations gave us a precise knowledge of the normal modes of vibration taking into account the type of coordination adopted by sulfate groups of this compound as ligands with C3v and C2v symmetries. A complete assignment of all the observed bands in the IR and Raman spectra for K5[B(SO4)4] was performed. Here, the infrared and Raman spectra of K5[B(SO4)4] were interpreted, discussed and completely assigned. The nature of the Ksbnd O, Ksbnd S, Bsbnd O, and Ssbnd O bonds and the topological properties of the compound were investigated and analyzed by means of Natural Bond Order (NBO) and Bader's Atoms in Molecules theory (AIM), respectively.

Conventional and microwave-assisted synthesis of new indole-tethered benzimidazole-based 1,2,3-triazoles and evaluation of their antimycobacterial, antioxidant and antimicrobial activities.

PubMed

Ashok, Dongamanti; Gundu, Srinivas; Aamate, Vikas Kumar; Devulapally, Mohan Gandhi

2018-04-18

A new series of triheterocycles containing indole-benzimidazole-based 1,2,3-triazole hybrids have been synthesized in good yields via a microwave-assisted click reaction. All the compounds were characterized by IR, [Formula: see text] NMR, [Formula: see text] NMR and mass spectroscopy and were evaluated for their in vitro antitubercular activity against the Mycobacterium tuberculosis H37Rv strain. Compounds 4b, 4h and 4i displayed highly potent antitubercular activity with MIC 3.125-6.25 [Formula: see text]. The antioxidant potential was evaluated using 2,2-diphenyl-1-picryl hydrazine and [Formula: see text] radical scavenging activity, and compounds 4e,4f and 4g showed excellent radical scavenging activity with [Formula: see text] values in the range of 08.50-10.05 [Formula: see text]. Furthermore, the compounds were evaluated for antimicrobial activity against numerous bacterial and fungal strains, and compounds 4b, 4c and 4h were found to be the most promising potential antimicrobial molecules with MIC 3.125-6.25 [Formula: see text].

Synthesis, dynamic NMR characterization and XRD studies of novel N,N'-substituted piperazines for bioorthogonal labeling.

PubMed

Mamat, Constantin; Pretze, Marc; Gott, Matthew; Köckerling, Martin

2016-01-01

Novel, functionalized piperazine derivatives were successfully synthesized and fully characterized by 1 H/ 13 C/ 19 F NMR, MS, elemental analysis and lipophilicity. All piperazine compounds occur as conformers resulting from the partial amide double bond. Furthermore, a second conformational shape was observed for all nitro derivatives due to the limited change of the piperazine chair conformation. Therefore, two coalescence points were determined and their resulting activation energy barriers were calculated using 1 H NMR. To support this result, single crystals of 1-(4-nitrobenzoyl)piperazine ( 3a , monoclinic, space group C 2/ c , a = 24.587(2), b = 7.0726(6), c = 14.171(1) Å, β = 119.257(8)°, V = 2149.9(4) Å 3 , Z = 4, D obs = 1.454 g/cm 3 ) and the alkyne derivative 4-(but-3-yn-1-yl)-1-(4-fluorobenzoyl)piperazine ( 4b , monoclinic, space group P 2 1 / n , a = 10.5982(2), b = 8.4705(1), c = 14.8929(3) Å, β = 97.430(1)°, V = 1325.74(4) Å 3 , Z = 4, D obs = 1.304 g/cm 3 ) were obtained from a saturated ethyl acetate solution. The rotational conformation of these compounds was also verified by XRD. As proof of concept for future labeling purposes, both nitropiperazines were reacted with [ 18 F]F - . To test the applicability of these compounds as possible 18 F-building blocks, two biomolecules were modified and chosen for conjugation either using the Huisgen-click reaction or the traceless Staudinger ligation.

Preparation, crystal structure and thermal decomposition kinetics of 1-(2,4-dinitrophenyl)azo-1-nitrocyclohexane

NASA Astrophysics Data System (ADS)

Yang, Desuo; Ma, Haixia; Hu, Rongzu; Song, Jirong; Zhao, Fengqi

2005-11-01

A new three-nitro-group compound of 1-(2,4-dinitrophenyl)azo-1-nitrocyclohexane was prepared by the reaction of cyclohexanone-2,4-dinitrophenylhydrazine with nitric oxide at ambient temperature. The single crystal structure has been determined by a four-circle X-ray diffractometer. The compound is monoclinic with space group P2(1)/ c and unit-cell parameters a=11.300(2) Å, b=12.993(2) Å, c=10.155(1) Å, β=98.33(1) o, F(000)=672, the unit-cell volume V=1475.2(5) Å 3, the molecule number in one unit-cell Z=4, the absorption coefficient μ=1.19 cm -1, the calculated density Dc=1.456 g cm -3. The exothermic decomposition reaction kinetics of the compound has been studied by DSC. The kinetic model function in differential form, apparent activation energy and pre-exponential constant of this reaction are (3/4)(1-α)[-ln(1-α)] 1/4, 123.88 kJ mol -1 and 10 11.49 s -1, respectively. The critical temperature of thermal explosion of the title compound is 161.15 oC and the entropy of activation (ΔS), enthalpy of activation (ΔH), and free energy of activation (ΔG) are -34.16 J mol -1 K -1, 115.7, and 130.48 kJ mol -1, respectively.

New metal oxides of the family Am[( TO) q]: ALiMn 3O 4 and ALiZn 3O 4 ( A = K, Rb)

NASA Astrophysics Data System (ADS)

Hoppe, R.; Seipp, E.; Baier, R.

1988-01-01

The new compounds KLiMn 3O 4 ( I), RbLiMn 3O 4 ( II), KLiZn 3O 4 ( III) and RbLiZn 3O 4 ( IV) have been prepared by solid state reaction of A2O ( A = K, Rb), Li 2O, and MO ( M = Mn, Zn). The isomorphous compounds are tetragonal, space group {I4}/{m}, Z = 2 , with lattice constants a = 838.32(4) pm, c = 341.88(3) pm for I; a = 840.66(8) pm, c = 344.85(4) pm for II; a = 819.27(9) pm, c = 334.20(7) pm for III,a = 823.62(9) pm, c = 339.73(7) pm for IV, as determined from Guinier X-ray powder patterns. The orange-colored manganates and colorless zincates are sensitive to moisture. The crystal structures of II and III have been determined by single-crystal X-ray techniques and refined to R = 0.09 ( II) and R = 0.06 ( III). The structure is built up from chains of face-shared cubes, 1∞[A O{8}/{2}] (A = K, Rb) , running parallel to the c axis. These are connected by Li + and M2+ ( M = Mn, Zn), statistically distributed on tetrahedral positions between the chains.

Development of α-glucosidase inhibitors by room temperature C-C cross couplings of quinazolinones.

PubMed

Garlapati, Ramesh; Pottabathini, Narender; Gurram, Venkateshwarlu; Kasani, Kumara Swamy; Gundla, Rambabu; Thulluri, Chiranjeevi; Machiraju, Pavan Kumar; Chaudhary, Avinash B; Addepally, Uma; Dayam, Raveendra; Chunduri, Venkata Rao; Patro, Balaram

2013-08-07

Novel quinazolinone based α-glucosidase inhibitors have been developed. For this purpose a virtual screening model has been generated and validated utilizing acarbose as a α-glucosidase inhibitor. Homology modeling, docking, and virtual screening were successfully employed to discover a set of structurally diverse compounds active against α-glucosidase. A search of a 3D database containing 22,500 small molecules using the structure based virtual model yielded ten possible candidates. All ten candidates were N-3-pyridyl-2-cyclopropyl quinazolinone-4-one derivatives, varying at the 6 position. This position was modified by Suzuki-Miyaura cross coupling with aryl, heteroaryl, and alkyl boronic acids. A catalyst screen was performed, and using the best optimal conditions, a series of twenty five compounds was synthesized. Notably, the C-C cross coupling reactions of the 6-bromo-2-cyclopropyl-3-(pyridyl-3-ylmethyl)quinazolin-4(3H)-one precursor have been accomplished at room temperature. A comparison of the relative reactivities of 6-bromo and 6-chloro-2,3-disubstituted quinazolinones with phenyl boronic acid was conducted. An investigation of pre-catalyst loading for the reaction of the 6-bromo-2-cyclopropyl-3-(pyridyl-3-ylmethyl)quinazolin-4(3H)-one substrate was also carried out. Finally, we submitted our compounds to biological assays against α-glucosidase inhibitors. Of these, three hits (compounds 4a, 4t and 4r) were potentially active as α-glucosidase inhibitors and showed activity with IC50 values <20 μM. Based on structural novelty and desirable drug-like properties, 4a was selected for structure-activity relationship study, and thirteen analogs were synthesized. Nine out of thirteen analogs acted as α-glucosidase inhibitors with IC50 values <10 μM. These lead compounds have desirable physicochemical properties and are excellent candidates for further optimization.

[Phenolic acid derivatives from Bauhinia glauca subsp. pernervosa].

PubMed

Zhao, Qiao-Li; Wu, Zeng-Bao; Zheng, Zhi-Hui; Lu, Xin-Hua; Liang, Hong; Cheng, Wei; Zhang, Qing-Ying; Zhao, Yu-Ying

2011-08-01

To study the chemical constituents of Bauhinia glauca subsp. pernervosa, eleven phenolic acids were isolated from a 95% ethanol extract by using a combination of various chromatographic techniques including column chromatography over silica gel, ODS, MCI, Sephadex LH-20, and semi-preparative HPLC. By spectroscopic techniques including 1H NMR, 13C NMR, 2D NMR, and HR-ESI-MS, these compounds were identified as isopropyl O-beta-(6'-O-galloyl)-glucopyranoside (1), ethyl O-beta-(6'-O-galloyl)-glucopyranoside (2), 3, 4, 5-trimethoxyphenyl-(6'-O-galloyl)-O-beta-D-glucopyranoside (3), 3, 4, 5-trimethoxyphenyl-beta-D-glucopyranoside (4), gallic acid (5), methyl gallate (6), ethyl gallate (7), protocatechuic acid (8), 3, 5-dimethoxy-4-hydroxybenzoic acid (9), erigeside C (10) and glucosyringic acid (11). Among them, compound 1 is a new polyhydroxyl compound; compounds 2, 10, and 11 were isolated from the genus Bauhinia for the first time, and the other compounds were isolated from the plant for the first time. Compounds 6 and 8 showed significant protein tyrosine phosphatase1B (PTP1B) inhibitory activity in vitro with the IC50 values of 72.3 and 54.1 micromol x L(-1), respectively.

Design, synthesis and biological evaluation of 4'-aminochalcone-rivastigmine hybrids as multifunctional agents for the treatment of Alzheimer's disease.

PubMed

Xiao, Ganyuan; Li, Yan; Qiang, Xiaoming; Xu, Rui; Zheng, Yunxiaozhu; Cao, Zhongcheng; Luo, Li; Yang, Xia; Sang, Zhipei; Su, Fu; Deng, Yong

2017-02-01

A series of 4'-aminochalcone-revastigmine hybrids were designed, synthesized and evaluated as multifunctional agents for the treatment of Alzheimer's disease. The results showed that most of these compounds exhibited good multifunctional activities. In particular, compound 6c displayed the best inhibitory potency on acetylcholinesterase (IC 50 =4.91μM), and significant antioxidative activity with a value 2.83-fold of Trolox. The kinetic analysis of AChE inhibition revealed that 6c showed mixed-type inhibition, binding simultaneously to the catalytic active site and peripheral anionic site of AChE. In addition, 6c inhibited self-induced Aβ 1-42 aggregation and Cu 2+ -induced Aβ 1-42 aggregation by 89.5% and 79.7% at 25μM respectively, as well as acted as a selective monoamine oxidase B inhibitor (IC 50 =0.29μM) and a selective biometal chelator. Furthermore, 6c could cross the blood-brain barrier in vitro. Based on these results, Compound 6c could be considered as a very promising lead compound for Alzheimer's disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

Trans-hemispheric contribution of C2-C10 α, ω-dicarboxylic acids, and related polar compounds to water-soluble organic carbon in the western Pacific aerosols in relation to photochemical oxidation reactions

NASA Astrophysics Data System (ADS)

SempéRé, Richard; Kawamura, Kimitaka

2003-06-01

Marine aerosol samples were collected during a western Pacific cruise covering the latitude range between 35°N and 40°S (140°E-180°E). They were analyzed for total carbon (TC), total nitrogen (TN), water-soluble organic carbon (WSOC) along with the molecular distributions of C2-C10 α, ω-dicarboxylic acids, and related polar compounds, mainly, ω-oxocarboxylic acids (C2-C9) and α-dicarbonyls (C2-C3). Oxalic acid (C2) was the most abundant followed by malonic (C3) and succinic (C4) acids. The total diacid concentration range was 7-605 ng m-3 (av. 85 ng m-3) and the diacid-carbon accounted for 2-15% (average 8%) of WSOC which comprised 29-55% (average 40%) of TC. Dry depositions of total diacids over the northern and southern Pacific Ocean were estimated to be 256-1907 μg m-2 yr-1 (average 735; n = 4) and 22-396 μg m-2 yr-1 (average 134; n = 14), respectively, whereas the air-to-sea flux of oxalic acid was 18-1351 μg m-2 yr-1 (average 466 μg m-2 yr-1) and 7.5-275 μg m-2 yr-1 (average 75 μg m-2 yr-1) in the Northern and Southern Hemispheres. We observed that the concentration ratios of diacid-C/WSOC, azelaic acid (C9)/ω-oxononanoic acid, maleic acid (iC4cis)/fumaric (iC4trans) acid and succinic acid (C4)/total diacids were correlated with air temperature. These findings showed that the intensity of photochemical oxidation reactions and thus the variation in sunlight intensity characterized here by air temperature, significantly control the molecular distribution of water-soluble organic compounds during the long-range transport of anthropogenic and/or biogenic higher molecular weight organic compounds.

Low Fermentation pH Is a Trigger to Alcohol Production, but a Killer to Chain Elongation.

PubMed

Ganigué, Ramon; Sánchez-Paredes, Patricia; Bañeras, Lluis; Colprim, Jesús

2016-01-01

Gasification of organic wastes coupled to syngas fermentation allows the recovery of carbon in the form of commodity chemicals, such as carboxylates and biofuels. Acetogenic bacteria ferment syngas to mainly two-carbon compounds, although a few strains can also synthesize four-, and six-carbon molecules. In general, longer carbon chain products have a higher biotechnological (and commercial) value due to their higher energy content and their lower water solubility. However, de-novo synthesis of medium-chain products from syngas is quite uncommon in acetogenic bacteria. An alternative to de-novo synthesis is bioproduction of short-chain products (C2 and C4), and their subsequent elongation to C4, C6, or C8 through reversed β-oxidation metabolism. This two-step synergistic approach has been successfully applied for the production of up to C8 compounds, although the accumulation of alcohols in these mixed cultures remained below detection limits. The present work investigates the production of higher alcohols from syngas by open mixed cultures (OMC). A syngas-fermenting community was enriched from sludge of an anaerobic digester for a period of 109 days in a lab-scale reactor. At the end of this period, stable production of ethanol and butanol was obtained. C6 compounds were only transiently produced at the beginning of the enrichment phase, during which Clostridium kluyveri, a bacterium able to carry out carbon chain elongation, was detected in the community. Further experiments showed pH as a critical parameter to maintain chain elongation activity in the co-culture. Production of C6 compounds was recovered by preventing fermentation pH to decrease below pH 4.5-5. Finally, experiments showed maximal production of C6 compounds (0.8 g/L) and alcohols (1.7 g/L of ethanol, 1.1 g/L of butanol, and 0.6 g/L of hexanol) at pH 4.8. In conclusion, low fermentation pH is critical for the production of alcohols, although detrimental to C. kluyveri. Fine control of fermentation pH to final values around 4.8 could allow sustained production of higher alcohols.

Synthesis, crystal structure, and vibrational study of K2Cu(HPO4)2·6H2O: A new metal hydrogenphosphate compound

NASA Astrophysics Data System (ADS)

Ettoumi, Houda; Bulou, Alain; Suñol, Joan Josep; Mhiri, Tahar

2015-11-01

The study reports on the synthesis, single-crystal X-ray structure, and infrared and polarized Raman spectra of a new metal phosphate. The chemical formula of the compound K2Cu(HPO4)2·6H2O resembled that of Tutton salts. The compound crystallized in the monoclinic system, space group P21/c, with a = 6.166(9), b = 12.118(19), c = 9.077(14) Å, β = 104.33(2), and Z = 2. The compound consisted of transition metal cations octahedrally coordinated by six water molecules, [Cu(H2O)6]2+, HPO4 pseudo-tetrahedra, and KO8 polyhedra. The KO8 polyhedra shared two edges with two HPO4 groups, two corners with the two other HPO4 groups, and two corners with Cu(H2O)6. The connection between [Cu(H2O)6]2+ octahedral and (HPO4)2- pseudo-tetrahedra was reinforced by hydrogen bonds formed between the water molecules and other oxygen atoms linked to the P atom. These structural results were corroborated by infrared and polarized Raman spectroscopy.

Synthesis, properties and crystal structure of (Gly) 2H 4SiW 12O 40·5.5H 2O

NASA Astrophysics Data System (ADS)

Lihua, Bi; Qizhuang, He; Qiong, Jia; Enbo, Wang

2001-10-01

A novel polyoxometalate containing Glycine (Gly), (Gly)2H4SiW12O40·5.5H2O (I), has been synthesized and characterized by single-crystal X-ray diffraction, elemental analyzes, IR spectrum, cyclic voltammograms and thermogravimetric analysis. The compound crystallizes in the monoclinic space group C2/C with a=40.362 (8) Å, b=12.478 (3) Å, c=19.879 (4) Å, β=96.22 (3)°, V=9953 (4) Å3, Z=8 and R1 (wR2)=0.0699 (0.1609). The crystal structure consists of [SiW12O40]4- units linked together with Gly molecules through hydrogen bonding. The electrochemical properties of I showed that the electrode reaction is surface-controlled. The compound has photosensitivity under irradiation of sunlight to result in charge transfer by oxidation of Gly and the reduction of SiW12O404-. We also found that the compound exhibited effectiveness in preventing cucumber mosaic virus (CMV).

Crystal structure of a photolysis product of vitamin B6: A pyridodihydrofuran-condensed skeleton compound of pyridoxal 5‧-phosphate

NASA Astrophysics Data System (ADS)

Aoki, Katsuyuki; Nakamura, Hideyuki; Hattori, Toshiaki; Hu, Ning-Hai; Onishi, Masayoshi

2017-11-01

An aqueous solution dissolving pyridoxal 5‧-phosphate (PLP) was exposed to sun-light at room temperature to yield a photolysis product, 4b,9b-dihydro-4b,9b-dihydroxy-1,6-dimethyl-4,9-bis(phosphonooxymethyl){pyrido[3‧,4‧:2,3]furo[4,5-b]}pyrido[4,3-d]furan (1), whose structure was crystallographically determined. The product 1 was found to be a novel C(sp3)-C(sp3) side-sharing pyridodihydrofuran-condensed skeleton compound with the two pyridodihydrofuran planes taking a 'V-shape'-like molecular configuration. Hydrogen bonding patterns of molecules of 1 in the crystal lattice are analyzed by the graph set approach. The most probable mechanism for the formation of 1 is described.

Induction of kranz anatomy and C4-like biochemical characteristics in a submerged amphibious plant by abscisic acid

PubMed Central

Ueno, O

1998-01-01

The amphibious leafless sedge Eleocharis vivipara develops C4-like traits as well as Kranz anatomy under terrestrial conditions, but it develops C3-like traits without Kranz anatomy under submerged conditions. When submerged plants are exposed to aerial conditions, they rapidly produce new photosynthetic tissues with C4-like traits. In this study, experiments were performed to determine whether abscisic acid (ABA), a plant stress hormone, could induce the formation of photosynthetic tissues with Kranz anatomy and C4-like biochemical traits under water in the submerged form. When the submerged plants were grown in water containing 5 &mgr;M ABA, they developed new photosynthetic tissues with Kranz anatomy, forming well-developed Kranz (bundle sheath) cells that contained many organelles. The ABA-induced tissues accumulated large amounts of phosphoenolpyruvate carboxylase, pyruvate orthophosphate dikinase, and NAD-malic enzyme at the appropriate cellular sites. The tissues had 3.4 to 3.8 times more C4 enzyme activity than did tissues of the untreated submerged plants. Carbon-14 pulse and carbon-12 chase experiments revealed that the ABA-induced tissues fixed higher amounts of carbon-14 into C4 compounds and lower amounts of carbon-14 into C3 compounds as initial products than did the submerged plants and that they exhibited a C4-like pattern of carbon fixation under aqueous conditions of low carbon, indicating enhanced C4 capacity in the tissues. This report provides an example of the hormonal control of the differentiation of the structural and functional traits required for the C4 pathway. PMID:9548983

Hybridization gap in the semiconducting compound SrIr 4In 2Ge 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calta, Nicholas P.; Im, Jino; Fang, Lei

Here, large single crystals of SrIr 4In 2Ge 4 were synthesized using the In flux method. This compound is a hybridization gap semiconductor with an experimental optical band gap of E g = 0.25(3) eV. It crystallizes in the tetragonal EuIr 4In 2Ge 4 structure type with space group 1more » $$\\overline{4}$$2m and unit cell parameters a = 6.9004(5) Å and c = 8.7120(9) Å. The electronic structure is very similar to both EuIr 4In 2Ge 4 and the parent structure Ca 3Ir 4Ge 4, suggesting that these compounds comprise a new family of hybridization gap materials that exhibit indirect gap, semiconducting behavior at a valence electron count of 60 per formula unit, similar to the Heusler alloys.« less

Hybridization gap in the semiconducting compound SrIr 4In 2Ge 4

DOE PAGES

Calta, Nicholas P.; Im, Jino; Fang, Lei; ...

2016-11-18

Here, large single crystals of SrIr 4In 2Ge 4 were synthesized using the In flux method. This compound is a hybridization gap semiconductor with an experimental optical band gap of E g = 0.25(3) eV. It crystallizes in the tetragonal EuIr 4In 2Ge 4 structure type with space group 1more » $$\\overline{4}$$2m and unit cell parameters a = 6.9004(5) Å and c = 8.7120(9) Å. The electronic structure is very similar to both EuIr 4In 2Ge 4 and the parent structure Ca 3Ir 4Ge 4, suggesting that these compounds comprise a new family of hybridization gap materials that exhibit indirect gap, semiconducting behavior at a valence electron count of 60 per formula unit, similar to the Heusler alloys.« less

Pyrazolo[3,4-c]isothiazole and isothiazolo[4,3-d]isoxazole derivatives as antifungal agents.

PubMed

Vicentini, Chiara Beatrice; Romagnoli, Carlo; Manfredini, Stefano; Rossi, Damiano; Mares, Donatella

2011-05-01

The diseases of plants and humans due to pathogenic fungi are increasing. Among the substances used to combat fungi, the azoles are of primary interest, both in agricultural field both in health. To avoid fungal resistance phenomena, the synthesis and tests of new derivatives are necessary. This article discusses the synthesis and the antifungal activity of pyrazolo[3,4-c]isothiazole and isothiazolo[4,3-d]isoxazole derivatives against three fungi that are pathogenic only for plants and two fungi that are opportunistic in humans and plants. The compounds were prepared starting from 2-cyano-3-ethoxy-2-butenethioamide. The antifungal activity of the compounds was determined by measuring the inhibition of growth of the fungi tested at 20, 50, and 100 µg/mL in comparison with the controls. Results demonstrated that several compounds were able to control the mycelial growth of the tested fungi, even if they showed different sensitivity to the different azole-derivatives. In general Magnaporthe grisea (T.T. Hebert) Yaegashi & Udagawa was the most sensitive fungus, being blocked almost entirely by 4-chloro derivative even at 20 µg/mL, a concentration at which the reference commercial compound tricyclazole was nearly ineffective. These findings demonstrate that the pyrazolo[3,4-c]isothiazole derivatives have a wide spectrum of activity on phytopathogenic and opportunistic fungi. In particular the 4-chloro derivative seems to have a great potential as new product to combat M. grisea in the agricultural field.

The intra-annular acylamide chelate-coordinated compound: The keto-tautomer of metal (II) milrinone complex

NASA Astrophysics Data System (ADS)

Gong, Yun; Liu, Jinzhi; Tang, Wang; Hu, Changwen

2008-03-01

In the presence of N, N'-dimethyllformamide (DMF), two isostructural metal (II)-milrinone complexes formulated as M(C 12H 8N 3O) 2 (M = Co 1 and Ni 2) have been synthesized and characterized by elemental analysis, IR, TG and single crystal X-ray diffraction. The two compounds crystallize in the tetragonal system, chiral space group P4 32 12. They exhibit similar two dimensional (2D) square grid-like framework, in which milrinone acts as a ditopic ligand with its terminal pyridine and intra-annular acylamide groups covalently bridging different metal centers. The intra-annular acylamide ligand shows a chelate-coordinated mode. Compounds 1 and 2 are stable under 200 °C. Compound 3 formulated as (C 12H 9N 3O) 4·H 2O was obtained in the presence of water, the water molecule in the structure leads to the racemization of compound 3 and it crystallizes in the monoclinic system, non-chiral space group P2 1/ c. Milrinone exhibits a keto-form in the three compounds and compounds 1- 3 exhibit different photoluminescence properties.

Ferrocenylaniline based amide analogs of methoxybenzoic acids: Synthesis, structural characterization and butyrylcholinesterase (BChE) inhibition studies

NASA Astrophysics Data System (ADS)

Altaf, Ataf Ali; Kausar, Samia; Hamayun, Muhammad; Lal, Bhajan; Tahir, Muhammad Nawaz; Badshah, Amin

2017-10-01

Three new ferrocene based amides were synthesized with slight structural difference. The general formula of the amides is C5H5FeC5H4C6H4NHCOC6H4(OCH3). The synthesized compounds were characterized by instrumental techniques like elemental analysis, FTIR and NMR spectroscopy. Structure of the two compounds was also studied by single crystal X-rays diffraction analysis. Structural studies provide the evidence that pMeO (one of the synthesized compounds) is an example of amides having no intermolecular hydrogen bonding in solid structure. In the BChE inhibition assay, compound (oMeO) having strong intermolecular force in the solid structure is less active than the compound (pMeO) with weak intermolecular forces in the solid structure. The docking studies proved that hydrogen bonding between inhibitor and BChE enzyme is of more importance for the activity, rather than intermolecular hydrogen bonding in the solid structure of inhibitor.

Photocatalytic Degradation of 4-Nitrophenol by C, N-TiO2: Degradation Efficiency vs. Embryonic Toxicity of the Resulting Compounds

NASA Astrophysics Data System (ADS)

Osin, Oluwatomiwa A.; Yu, Tianyu; Cai, Xiaoming; Jiang, Yue; Peng, Guotao; Cheng, Xiaomei; Li, Ruibin; Qin, Yao; Lin, Sijie

2018-06-01

The photocatalytic activity of TiO2 based photocatalysts can be improved by structural modification and elemental doping. In this study, through rational design, one type of carbon and nitrogen co-doped TiO2 (C, N-TiO2) photocatalyst with mesoporous structure was synthesized with improved photocatalytic activity in degrading 4-nitrophenol under simulated sunlight irradiation. The photocatalytic degradation efficiency of the C, N-TiO2 was much higher than the anatase TiO2 (A-TiO2) based on absorbance and HPLC analyses. Moreover, using zebrafish embryos, we showed that the intermediate degradation compounds generated by photocatalytic degradation of 4-nitrophenol had higher toxicity than the parent compound. A repeated degradation process was necessary to render complete degradation and non-toxicity to the zebrafish embryos. Our results demonstrated the importance of evaluating the photocatalytic degradation efficiency in conjunction with the toxicity assessment of the degradation compounds.

Photocatalytic Degradation of 4-Nitrophenol by C, N-TiO2: Degradation Efficiency vs. Embryonic Toxicity of the Resulting Compounds.

PubMed

Osin, Oluwatomiwa A; Yu, Tianyu; Cai, Xiaoming; Jiang, Yue; Peng, Guotao; Cheng, Xiaomei; Li, Ruibin; Qin, Yao; Lin, Sijie

2018-01-01

The photocatalytic activity of TiO 2 based photocatalysts can be improved by structural modification and elemental doping. In this study, through rational design, one type of carbon and nitrogen co-doped TiO 2 (C, N-TiO 2 ) photocatalyst with mesoporous structure was synthesized with improved photocatalytic activity in degrading 4-nitrophenol under simulated sunlight irradiation. The photocatalytic degradation efficiency of the C, N-TiO 2 was much higher than the anatase TiO 2 (A-TiO 2 ) based on absorbance and HPLC analyses. Moreover, using zebrafish embryos, we showed that the intermediate degradation compounds generated by photocatalytic degradation of 4-nitrophenol had higher toxicity than the parent compound. A repeated degradation process was necessary to render complete degradation and non-toxicity to the zebrafish embryos. Our results demonstrated the importance of evaluating the photocatalytic degradation efficiency in conjunction with the toxicity assessment of the degradation compounds.

Nature and kinetic analysis of carbon-carbon bond fragmentation reactions of cation radicals derived from SET-oxidation of lignin model compounds.

PubMed

Cho, Dae Won; Parthasarathi, Ramakrishnan; Pimentel, Adam S; Maestas, Gabriel D; Park, Hea Jung; Yoon, Ung Chan; Dunaway-Mariano, Debra; Gnanakaran, S; Langan, Paul; Mariano, Patrick S

2010-10-01

Features of the oxidative cleavage reactions of diastereomers of dimeric lignin model compounds, which are models of the major types of structural units found in the lignin backbone, were examined. Cation radicals of these substances were generated by using SET-sensitized photochemical and Ce(IV) and lignin peroxidase promoted oxidative processes, and the nature and kinetics of their C-C bond cleavage reactions were determined. The results show that significant differences exist between the rates of cation radical C1-C2 bond cleavage reactions of 1,2-diaryl-(β-1) and 1-aryl-2-aryloxy-(β-O-4) propan-1,3-diol structural units found in lignins. Specifically, under all conditions C1-C2 bond cleavage reactions of cation radicals of the β-1 models take place more rapidly than those of the β-O-4 counterparts. The results of DFT calculations on cation radicals of the model compounds show that the C1-C2 bond dissociation energies of the β-1 lignin model compounds are significantly lower than those of the β-O-4 models, providing clear evidence for the source of the rate differences.

Insights into the intramolecular donor stabilisation of organostannylene palladium and platinum complexes: syntheses, structures and DFT calculations.

PubMed

Wagner, Michael; Deáky, Vajk; Dietz, Christina; Martincová, Jana; Mahieu, Bernard; Jambor, Roman; Herres-Pawlis, Sonja; Jurkschat, Klaus

2013-05-17

The syntheses of the transition metal complexes cis-[(4-tBu-2,6-{P(O)(OiPr)2}2C6H2SnCl)2MX2] (1, M = Pd, X = Cl; 2, M = Pd, X = Br; 3, M = Pd, X = I; 4, M = Pt, X = Cl), cis-[{2,6-(Me2NCH2)2C6H3SnCl}2MX2] (5, M = Pd, X = I; 6, M = Pt, X = Cl), trans-[{2,6-(Me2NCH2)2C6H3SnI}2PtI2] (7) and trans-[(4-tBu-2,6-{P(O)(OiPr)2}2C6H2SnCl)PdI2]2 (8) are reported. Also reported is the serendipitous formation of the unprecedented complexes trans-[(4-tBu-2,6-{P(O)(OiPr)2}2C6H2SnCl)2Pt(SnCl3)2] (10) and [(4-tBu-2,6-{P(O)(OiPr)2}2C6H2SnCl)3Pt(SnCl3)2] (11). The compounds were characterised by elemental analyses, (1)H, (13)C, (31)P, (119)Sn and (195)Pt NMR spectroscopy, single-crystal X-ray diffraction analysis, UV/Vis spectroscopy and, in the cases of compounds 1, 3 and 4, also by Mössbauer spectroscopy. All the compounds show the tin atoms in a distorted trigonal-bipyramidal environment. The Mössbauer spectra suggest the tin atoms to be present in the oxidation state III. The kinetic lability of the complexes was studied by redistribution reactions between compounds 1 and 3 as well as between 1 and cis-[{2,6-(Me2 NCH2)2C6H3SnCl}2PdCl2]. DFT calculations provided insights into both the bonding situation of the compounds and the energy difference between the cis and trans isomers. The latter is influenced by the donor strength of the pincer-type ligands. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ripening and storage conditions of Chétoui and Arbequina olives: Part I. Effect on olive oils volatiles profile.

PubMed

Hachicha Hbaieb, Rim; Kotti, Faten; Gargouri, Mohamed; Msallem, Monji; Vichi, Stefania

2016-07-15

The distinctive aroma of virgin olive oil is mainly attributed to its volatile profile including components responsible for positive attributes and others for sensory defects resulting from chemical oxidation and exogenous enzymes. For this reason, the evolution of volatile compounds from Chétoui and Arbequina virgin olive oils during olive ripening and storage (at 4 and 25 °C during 4 weeks) was investigated. The profile of volatile phenols during olive storage was also studied. Quantitative differences in the volatile compounds during olive storage at 4 and 25 °C according to olive cultivar was determined. Concerning the volatile phenols, the Arbequina olives were the most affected by high storage temperature, as the formation of these compounds, especially 4-ethyl and 4-vinyl derivatives of phenol and guaiacol were more noticeable in Arbequina oils extracted from stored fruits at 25 °C. Copyright © 2016 Elsevier Ltd. All rights reserved.

Novel aldehyde and thiosemicarbazone derivatives: Synthesis, spectroscopic characterization, structural studies and molecular docking studies

NASA Astrophysics Data System (ADS)

Karakurt, Tuncay; Tahtaci, Hakan; Subasi, Nuriye Tuna; Er, Mustafa; Ağar, Erbil

2016-12-01

In this study our purpose is that, synthesis and characterization of compounds containing the aldehyde and thiosemicarbazone groups and comparison of the theoretical results with the experimental results. The structures of all synthesized compounds were elucidated by IR, 1H NMR, 13C NMR, elemental analyses techniques. The structure of compound (4) (C9H8N4O2S) was also elucidated by X-ray diffraction analysis. In addition, the theoretical IR spectrum, 1H NMR and 13C NMR chemical shift values, frontier molecular orbital values (FMO) of these molecules were analyzed by using Becke-3- Lee-Yang-Parr (B3LYP) method with LanL2DZ basis set. Finally, molecular docking studies were performed on synthesized compounds using the 4DKI beta-lactam protein structure to determine the potential binding mode of inhibitors.

Mechanistic investigations of imine hydrogenation catalyzed by cationic iridium complexes.

PubMed

Martín, Marta; Sola, Eduardo; Tejero, Santiago; Andrés, José L; Oro, Luis A

2006-05-15

Complexes [IrH2(eta6-C6H6)(PiPr3)]BF4 (1) and [IrH2(NCMe)3(PiPr3)]BF4 (2) are catalyst precursors for homogeneous hydrogenation of N-benzylideneaniline under mild conditions. Precursor 1 generates the resting state [IrH2{eta5-(C6H5)NHCH2Ph}(PiPr3)]BF4 (3), while 2 gives rise to a mixture of [IrH{PhN=CH(C6H4)-kappaN,C}(NCMe)2(PiPr3)]BF4 (4) and [IrH{PhN=CH(C6H4)-kappaN,C}(NCMe)(NH2Ph)(PiPr3)]BF4 (5), in which the aniline ligand is derived from hydrolysis of the imine. The less hindered benzophenone imine forms the catalytically inactive, doubly cyclometalated compound [Ir{HN=CPh(C6H4)-kappaN,C}2(NH2CHPh2)(PiPr3)]BF4 (6). Hydrogenations with precursor 1 are fast and their reaction profiles are strongly dependent on solvent, concentrations, and temperature. Significant induction periods, minimized by addition of the amine hydrogenation product, are commonly observed. The catalytic rate law (THF) is rate = k[1][PhN=CHPh]p(H2). The results of selected stoichiometric reactions of potential catalytic intermediates exclude participation of the cyclometalated compounds [IrH{PhN=CH(C6H4)-kappaN,C}(S)2(PiPr3)]BF4 [S = acetonitrile (4), [D6]acetone (7), [D4]methanol (8)] in catalysis. Reactions between resting state 3 and D2 reveal a selective sequence of deuterium incorporation into the complex which is accelerated by the amine product. Hydrogen bonding among the components of the catalytic reaction was examined by MP2 calculations on model compounds. The calculations allow formulation of an ionic, outer-sphere, bifunctional hydrogenation mechanism comprising 1) amine-assisted oxidative addition of H2 to 3, the result of which is equivalent to heterolytic splitting of dihydrogen, 2) replacement of a hydrogen-bonded amine by imine, and 3) simultaneous H delta+/H delta- transfer to the imine substrate from the NH moiety of an arene-coordinated amine ligand and the metal, respectively.

Stereoselective synthesis, spectral and antimicrobial studies of some cyanoacetyl hydrazones of 3-alkyl-2,6-diarylpiperidin-4-ones

NASA Astrophysics Data System (ADS)

Velayutham Pillai, M.; Rajeswari, K.; Vidhyasagar, T.

2014-11-01

A series of novel cyanoacetyl hydrazones of 3-alkyl-2,6-diarylpiperidin-4-ones were synthesized stereoselectively and characterized by IR, Mass, 1H NMR, 13C NMR, 1H-1H COSY and 1H-13C COSY spectra. The stereochemistry of the synthesized compounds was established using NMR spectra. Antimicrobial screening of the synthesized compounds revealed their antibacterial and antifungal potencies. Growth inhibition of Enterobacter Aerogenes by compound 15 was found to be superior to the standard drug.

Dipropyl 3,6-diphenyl-1,2-dihydro-1,2,4,5-tetrazine-1,2-dicarboxylate.

PubMed

Rao, Guo-Wu; Hu, Wei-Xiao

2003-05-01

The title compound, C(22)H(24)N(4)O(4), was prepared from propyl chloroformate and 3,6-diphenyl-1,2-dihydro-s-tetrazine. This reaction yields the title compound rather than dipropyl 3,6-diphenyl-1,4-dihydro-s-tetrazine-1,4-dicarboxylate. The 2,3-diazabutadiene group in the central six-membered ring is not planar; the C=N double-bond length is 1.285 (2) A, and the average N-N single-bond length is 1.401 (3) A, indicating a lack of conjugation. The ring has a twist conformation, in which adjacent N atoms lie +/- 0.3268 (17) A from the plane of the ring. The molecule has twofold crystallographic symmetry.

Alterations in cholesterol and fatty acid biosynthesis in rat liver homogenates by aryloxy acids (Short Communication)

PubMed Central

Olson, Robert J.; Trumble, Thomas E.; Gamble, Wilbert

1974-01-01

2,4-Dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid inhibited the incorporation of [2-14C]mevalonate into cholesterol and non-saponifiable lipids. Both compounds inhibited the conversion of [1-14C]isopentenyl pyrophosphate into cholesterol and the synthesis of cholesterol and fatty acids from [2-14C]acetate. There was no inhibition of the conversion of [1-14C]mevalonate into CO2. At low concentrations (0.5mm) of the compounds there was a stimulation of acetate incorporation into fatty acids. PMID:4441387

Synthesis and preliminary in vitro biological evaluation of new carbon-11-labeled celecoxib derivatives as candidate PET tracers for imaging of COX-2 expression in cancer.

PubMed

Gao, Mingzhang; Wang, Min; Miller, Kathy D; Zheng, Qi-Huang

2011-09-01

The enzyme cyclooxygenase-2 (COX-2) is overexpressed in a variety of malignant tumors. This study was designed to develop new radiotracers for imaging of COX-2 in cancer using biomedical imaging technique positron emission tomography (PET). Carbon-11-labeled celecoxib derivatives, [(11)C]4a-c and [(11)C]8a-d, were prepared by O-[(11)C] methylation of their corresponding precursors using [(11)C]CH(3)OTf under basic conditions and isolated by a simplified solid-phase extraction (SPE) method in 52 ± 2% (n = 5) and 57 ± 3% (n = 5) radiochemical yields based on [(11)C]CO(2) and decay corrected to end of bombardment (EOB). The overall synthesis time from EOB was 23 min, the radiochemical purity was >99%, and the specific activity at end of synthesis (EOS) was 277.5 ± 92.5 GBq/μmol (n = 5). The IC(50) values to block COX-2 for known compounds celecoxib (4d), 4a and 4c were 40, 290 and 8 nM, respectively, and preliminary findings from in vitro biological assay indicated that the synthesized new compounds 4b and 8a-d display similar strong inhibitory effectiveness in the MDA-MB-435 human cancer cell line in comparison with the parent compound 4d. These results encourage further in vivo evaluation of carbon-11-labeled celecoxib derivatives as new potential PET radiotracers for imaging of COX-2 expression in cancer. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Target identification, lead optimization and antitumor evaluation of some new 1,2,4-triazines as c-Met kinase inhibitors.

PubMed

El-Wakil, Marwa H; Ashour, Hayam M; Saudi, Manal N; Hassan, Ahmed M; Labouta, Ibrahim M

2017-08-01

In silico target fishing approach using PharmMapper server identified c-Met kinase as the selective target for our previously synthesized compound NCI 748494/1. This approach was validated by in vitro kinase assay which showed that NCI 748494/1 possessed promising inhibitory activity against c-Met kinase (IC 50 =31.70μM). Assessment of ADMET profiling, drug-likeness, drug score as well as docking simulation for the binding pose of that compound in the active site of c-Met kinase domain revealed that NCI 748494/1 could be considered as a promising drug lead. Based on target identification and validation, it was observed that there is structure similarity between NCI 748494/1 and the reported type II c-Met kinase inhibitor BMS-777607. Optimization of our lead NCI 748494/1 furnished newly synthesized 1,2,4-triazine derivatives based on well-established structure-activity relationships, whereas three compounds namely; 4d, 7a and 8c displayed excellent in vitro cytotoxicity against three c-Met addicted cancer cell lines; A549 (lung adenocarcinoma), HT-29 (colon cancer) and MKN-45 (gastric carcinoma); with IC 50 values in the range 0.01-1.86µM. In vitro c-Met kinase assay showed 8c to possess the highest c-Met kinase inhibition profile (IC 50 =4.31µM). Docking of the active compounds in c-Met kinase active site revealed strong binding interactions comparable to the lead NCI 748494/1 and BMS-777607, suggesting that c-Met inhibition is very likely to be the mechanism of the antitumor effect of these derivatives. Copyright © 2017 Elsevier Inc. All rights reserved.

Fast-Rate Capable Electrode Material with Higher Energy Density than LiFePO4: 4.2V LiVPO4F Synthesized by Scalable Single-Step Solid-State Reaction.

PubMed

Kim, Minkyung; Lee, Seongsu; Kang, Byoungwoo

2016-03-01

Use of compounds that contain fluorine (F) as electrode materials in lithium ion batteries has been considered, but synthesizing single-phase samples of these compounds is a difficult task. Here, it is demonstrated that a simple scalable single-step solid-state process with additional fluorine source can obtain highly pure LiVPO 4 F. The resulting material with submicron particles achieves very high rate capability ≈100 mAh g -1 at 60 C-rate (1-min discharge) and even at 200 C-rate (18 s discharge). It retains superior capacity, ≈120 mAh g -1 at 10 C charge/10 C discharge rate (6-min) for 500 cycles with >95% retention efficiency. Furthermore, LiVPO 4 F shows low polarization even at high rates leading to higher operating potential >3.45 V (≈3.6 V at 60 C-rate), so it achieves high energy density. It is demonstrated for the first time that highly pure LiVPO 4 F can achieve high power capability comparable to LiFePO 4 and much higher energy density (≈521 Wh g -1 at 20 C-rate) than LiFePO 4 even without nanostructured particles. LiVPO 4 F can be a real substitute of LiFePO 4.

Combined strategy for phytotoxicity enhancement of benzoxazinones.

PubMed

Macías, Francisco A; Chinchilla, Nuria; Arroyo, Elena; Molinillo, José M G; Marín, David; Varela, Rosa M

2010-02-10

Fifteen new derivatives of D-DIBOA, including aromatic ring modifications and the addition of side chains in positions C-2 and N-4, were synthesized and their phytotoxicity, selectivity, and structure-activity relationships evaluated. The most active compounds among the derivatives at the C-2 position were 6-Cl-2-Et-D-DIBOA and 6-F-2-Et-D-DIBOA. Of the derivatives at N-4, the most active compounds were 6-Cl-4-Pr-D-DIBOA and 6-Cl-4-Val-D-DIBOA. These four compounds showed high levels of inhibition in root length at very low concentrations in all species. The most remarkable result is the 70% inhibition observed for the root length of cress at 100 nM caused by the latter two compounds. These results support our previous research and conclusions regarding the steric, electronic, and solubility requirements to achieve the maximum phytotoxic activity.

Organotin Selenide Clusters and Hybrid Capsules.

PubMed

Dehnen, Stefanie; Hanau, Katharina; Rinn, Niklas; Argentari, Mario

2018-05-22

Several compounds with unique structural motifs that have already been known from organotin sulfide chemistry, but remained unprecedented in organotin selenide chemistry so far, have been synthesized. The reaction of [(R1Sn)4Se6] (R1 = CMe2CH2C(O)Me) with N2H4·H2O/(SiMe3)2Se and with PhN2H3/(SiMe3)2Se led to the formation of [{(R2Sn)2SnSe4}2(µ-Se)2] (1) and [{(R3Sn)2SnSe4}2(µ-Se)2] (2) (R2 = CMe2CH2C(Me)NNH2, R3 = CMe2CH2C(Me)NNPhH), respectively. Addition of o-phthalaldehyde to [(R2Sn)4Se6] yielded a cluster with intramolecular bridging of the organic groups, [(R4Sn2)2Se6] (3, R4 = (CMe2CH2C(Me)NNCH)2C6H4). The introduction of organic ligands with longer chains finally allowed the isolation of inorganic-organic capsules of the type [(µ-R)3(Sn3Se4)2]X2, with R = (CMe2CH2C(Me)NNHC(O))2(CH2)4, X = [SnC3], Cl (4a, 4b) or R = CMe2CH2C(Me)NNH)2, X = [SnCl3] (5). The capsules enclose solvent molecules and/or anions as guests. All compounds were characterized via single-crystal X-ray diffraction, NMR spectroscopy and mass spectrometry. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Trangmolins A-F with an Unprecedented Structural Plasticity of the Rings A and B: New Insight into Limonoid Biosynthesis.

PubMed

Li, Wanshan; Shen, Li; Bruhn, Torsten; Pedpradab, Patchara; Wu, Jun; Bringmann, Gerhard

2016-08-08

The absolute stereostructures of trangmolins A-F (1-6), limonoids with three new and one known topologies of the rings A and B, were unambiguously determined by NMR spectroscopic investigations, single-crystal XRD analysis, and quantum-chemical electronic circular dichroism calculations. Compounds 1-3 contain a hexahydro-1H-inden-4-one motif, compound 4 comprises a hexahydro-2,6-methanobenzofuran-7-one cage, and compound 5 consists of a hexahydro-2H-2,8-epoxychromene scaffold. The C1-C30 linkage in 1-3 and the C3-C30 connection in 4 form two unprecedented types of ring A/B-fused carbobicyclic cores: viii and ix. The oxidative cleavage of the C2-C3 bond in 5 and heterocyclization in 4 and 5 constitute the unprecedented tricyclic 6/6/5 ring A/B(1) /B(2) - and 6/5/6 ring A(1) A(2) /B-fused topologies, respectively, which are uncovered, for the first time, in the construction of limonoid architectures. The diverse cyclization patterns of 1-6 reveal an unparalleled structural plasticity of rings A and B in limonoid biosynthesis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemical constituents of Cichorium intybus and their inhibitory effects against urease and alpha-chymotrypsin enzymes.

PubMed

Saied, Sumayya; Shah, Shazia; Ali, Zulfiqar; Khan, Ajmal; Marasini, Bishnu P; Choudhary, Muhammad Iqbal

2011-08-01

Phytochemical investigation of the aerial parts of Cichorium intybus L. resulted in the isolation and identification of two new natural metabolites, 2,6-di[but-3(E)-en-2-onyl]naphthalene (1), and 3,3',4,4'-tetrahydroxychalcone (2), along with nine known compounds. Their structures were determined by spectroscopic techniques including 1D and 2D NMR. The known compounds were identified as scopoletin (3), 4-hydroxyphenylacetic acid (4), 3-hydroxy-4-methoxybenzoic acid (5), 4,4'-dihydroxychalcone (6), 6,7-dihydroxycoumarine (7), 1-triacontanol (8), lupeol (9), beta-sitosterol (10), and beta-sitosterol-3-O-beta-glucopyranoside (11). Compounds 4-6 and 8 are reported for the first time from C. intybus. Compounds 2 and 3 showed weak inhibitory activities against urease and alpha-chymotrypsin enzymes, respectively.

Copper(II) perrhenate Cu(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2}: Synthesis from isopropanol and CuReO{sub 4}, structure and properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mikhailova, D., E-mail: d.mikhailova@ifw-dresden.de; Institute for Complex Materials, IFW Dresden, Helmholtzstrasse 20, D-01069 Dresden; Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, D-01187 Dresden

2015-12-15

The crystal structure of Cu{sup +}Re{sup 7+}O{sub 4} is capable of a quasi-reversible incorporation of C{sub 3}H{sub 7}OH molecules. A room-temperature reaction between CuReO{sub 4} and C{sub 3}H{sub 7}OH under oxidizing conditions leads to the formation of a novel metal-organic hybrid compound Cu{sup 2+}(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2}. Upon heating under reducing conditions, this compound transforms back into CuReO{sub 4}, albeit with ReO{sub 2} and metallic Cu as by-products. The crystal structure of Cu(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2} solved from single-crystal X-ray diffraction (Pbca, a=10.005(3) Å, b=7.833(2) Å, and c=19.180(5) Å) reveals layers of corner-sharing CuO{sub 6}-octahedra andmore » ReO{sub 4}-tetrahedra, whereas isopropyl groups are attached to both sides of these layers, thus providing additional connections within the layers through hydrogen bonds. Cu(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2} is paramagnetic down to 4 K because the spatial arrangement of the Cu{sup 2+} half-filled orbitals prevents magnetic superexchange. The paramagnetic effective moment of 2.0(1) μ{sub B} is slightly above the spin-only value and typical for Cu{sup 2+} ions. - Highlights: • Novel Cu(C{sub 3}H{sub 7}OH){sub 2}(ReO{sub 4}){sub 2} compound has a sequence of inorganic and organic layers. • Hydrogen bonds provide an additional bonding Isopropanol molecules serve as a reducing agent during decomposition. • No direct Cu-O-Re-O-Cu connections via d{sub x2-y2} orbital of Cu{sup 2+} explain paramagnetism. • Hydrogen bonds provide an additional bonding. • Isopropanol molecules serve as a reducing agent during decomposition.« less

Enhancement of Phenolic Production and Antioxidant Activity from Buckwheat Leaves by Subcritical Water Extraction.

PubMed

Kim, Dong-Shin; Kim, Mi-Bo; Lim, Sang-Bin

2017-12-01

To enhance the production of phenolic compounds with high antioxidant activity and reduce the level of phototoxic fagopyrin, buckwheat leaves were extracted with subcritical water (SW) at 100~220°C for 10~50 min. The major phenolic compounds were quercetin, gallic acid, and protocatechuic acid. The cumulative amount of individual phenolic compounds increased with increasing extraction temperature from 100°C to 180°C and did not change significantly at 200°C and 220°C. The highest yield of individual phenolic compounds was 1,632.2 μg/g dry sample at 180°C, which was 4.7-fold higher than that (348.4 μg/g dry sample) at 100°C. Total phenolic content and total flavonoid content increased with increasing extraction temperature and decreased with increasing extraction time, and peaked at 41.1 mg gallic acid equivalents/g and 26.9 mg quercetin equivalents/g at 180°C/10 min, respectively. 2,2-Diphenyl-1-picrylhydrazyl free radical scavenging activity and ferric reducing ability of plasma reached 46.4 mg ascorbic acid equivalents/g and 72.3 mmol Fe 2+ /100 g at 180°C/10 min, respectively. The fagopyrin contents were reduced by 92.5~95.7%. Color values L * and b * decreased, and a * increased with increasing extraction temperature. SW extraction enhanced the yield of phenolic compounds with high antioxidant activity and reduced the fagopyrin content from buckwheat leaves.

Ruthenium(III)/phosphine/pyridine complexes applied in the hydrogenation reactions of polar and apolar double bonds

NASA Astrophysics Data System (ADS)

Rodrigues, Claudia; Delolo, Fábio G.; Ferreira, Lucas M.; da S. Maia, Pedro I.; Deflon, Victor M.; Rabeah, Jabor; Brückner, Angelika; Norinder, Jakob; Börner, Armin; Bogado, André L.; Batista, Alzir A.

2016-05-01

In this work, five ruthenium(III) complexes containing phosphine and pyridine based ligands with general formula mer-[RuCl3(dppb)(N)] [where dppb = 1,4-bis(diphenylphosphino)butane and N = pyridine (py), 4-methylpyridine (4-Mepy), 4-vinylpyridine (4-Vpy), 4-tert-butylpyridine (4-tBupy) and 4-phenylpyridine (4-Phpy)] were synthesized and characterized using spectroscopic and electrochemical techniques, as well as magnetic susceptibility to check the paramagnetism of these compounds. These complexes were tested as catalytic precursors in hydrogenation reactions with cyclohexene, undecanal and cyclohexanecarboxaldehyde, as compounds bearing Cdbnd C and Cdbnd O groups. Broad screening was carried out in order to find the optimal reaction conditions with the highest conversion. It was found that by using a ratio of Ru-catalyst/substrate = 1:530 at 80 °C and 15 bar of H2 for 24 h, cyclohexene can be reduced. Hydrogenation of undecanal was possible using a Ru-catalyst/substrate ratio of 1:100 at 160 °C and 100 bar for 24 h, and for the reduction of cyclohexanecarboxaldehyde the reaction conditions were Ru-catalyst/substrate ratio of 1:100 at 160 °C and 50 bar for 24 h.

Synthesis and characterization of new fluorescent styrene-containing carborane derivatives: the singular quenching role of a phenyl substituent.

PubMed

Ferrer-Ugalde, Albert; Juárez-Pérez, Emilio José; Teixidor, Francesc; Viñas, Clara; Sillanpää, Reijo; Pérez-Inestrosa, Ezequiel; Núñez, Rosario

2012-01-09

A set of neutral and anionic carborane derivatives in which the styrenyl fragment is introduced as a fluorophore group has been successfully synthesized and characterized. The reaction of the monolithium salts of 1-Ph-1,2-C(2)B(10)H(11), 1-Me-1,2-C(2)B(10)H(11) and 1,2-C(2)B(10)H(12) with one equivalent of 4-vinylbenzyl chloride leads to the formation of compounds 1-3, whereas the reaction of the dilithium salt of 1,2-C(2)B(10)H(12) with two equivalents of 4-vinylbenzyl chloride gives disubstituted compound 4. The closo clusters were degraded using the classical method, KOH in EtOH, to afford the corresponding nido species, which were isolated as tetramethylammonium salts. The crystal structure of the four closo compounds 1-4 were analyzed by X-ray diffraction. All compounds, except 1, display emission properties, with quantum yields dependent on the nature of the cluster (closo or nido) and the substituent on the second C(cluster) atom. In general, closo compounds 2-4 exhibit high fluorescence emission, whereas the presence of a nido cluster produces a decrease of the emission intensity. The presence of a phenyl group bonded to the C(cluster) results in an excellent electron-acceptor unit that produces a quenching of the fluorescence. DFT calculations have confirmed the charge-separation state in 1 to explain the quenching of the fluorescence and the key role of the carboranyl fragment in this luminescent process. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Elastic moduli of the distorted Kagome-lattice ferromagnet Nd3Ru4Al12

NASA Astrophysics Data System (ADS)

Suzuki, Takashi; Mizuno, Takuyou; Takezawa, Kohki; Kamikawa, Shuhei; Andreev, Alexander V.; Gorbunov, Denis I.; Henriques, Margarida S.; Ishii, Isao

2018-05-01

The distorted kagome-lattice compound Nd3Ru4Al12 has the hexagonal structure. This compound is reported as a ferromagnet in which spins are aligned along the c-axis with the Curie temperature TC = 39 K . The nature of localized f-electrons is expected in Nd3Ru4Al12, and magnetic anisotropy can be attributed to a crystal electric field (CEF) effect. We performed ultrasonic measurements on a Nd3Ru4Al12 single-crystalline sample in order to investigate the phase transition at TC and the CEF effect. All longitudinal and transverse elastic moduli increase monotonically with decreasing temperature, and no clear elastic softening due to a quadrupole interaction is detected under the hexagonal CEF. This result is in contrast to an isomorphic compound Dy3Ru4Al12 with a remarkable elastic softening of the transverse modulus C44. At the ferromagnetic phase transition, the moduli show obvious elastic anomalies, suggesting characteristic couplings between a strain and a magnetic order parameter.

Phase homology in new layered mixed Li, M (M=Mg, Cu, Cd, Pb, Bi) bismuth oxophosphates and oxoarsenates

NASA Astrophysics Data System (ADS)

Kozin, M. S.; Colmont, M.; Endara, D.; Aliev, A.; Huvé, M.; Siidra, O. I.; Krivovichev, S. V.; Mentré, O.

2013-03-01

Single crystals of two novel bismuth oxocompounds were grown from melts and the corresponding pure powders obtained from solid state reactions. Both compounds were structurally characterized using X-Ray diffraction techniques. [Bi7O7][BiO]7Cd1Li2(PO4)6 (1) is monoclinic, C2/m, a=26.9234(23), b=5.2926(5), c=12.3024(10) Å, β=106.45(5)°, R1=0.042 and ωR2=0.062. The crystal structure of 1 is related to that of [Bi7O7][BiO]7Bii0.66Li2(PO4)6 and consists of the [Bi7O7]7+ tetrahedral layers with the [(BiO)7CdLi2(PO4)6]7- interlayer blocks, where [BiO]+ denotes units attached to the layers of oxocentered tetrahedra. [Bi4O4][BiO]4Cu1Li2(AsO4)4 (2) is monoclinic, P21/c, a=8.8133(4), b=24.346(1), c=5.4056(2) Å, β=106,93(2)°, R1=0.031 and ωR2=0.035. The crystal structure of 2 is based upon layers similar to those observed in 1, but with the modified topology of the interlayer block. Both compounds can be considered as derivatives from the parent δ-Bi2O3 fluorite-like structure, where phosphorus and arsenic atoms substitute for some Bi sites. The arrangement of the [BiO]+ layers and the XO4 (X=P, As) interlayer groups is significantly modified compared to the previously known Cd compound. The comparison and review of the related structures is given. The variety of aliovalent cations able to incorporate in the interlayer as well as the strong structural resemblance with the Aurivillius series compounds establishes the new routes for the further prospective syntheses of novel but related phases with various important applications.

C4 Cycles: Past, Present, and Future Research on C4 Photosynthesis

PubMed Central

Langdale, Jane A.

2011-01-01

In the late 1960s, a vibrant new research field was ignited by the discovery that instead of fixing CO2 into a C3 compound, some plants initially fix CO2 into a four-carbon (C4) compound. The term C4 photosynthesis was born. In the 20 years that followed, physiologists, biochemists, and molecular and developmental biologists grappled to understand how the C4 photosynthetic pathway was partitioned between two morphologically distinct cell types in the leaf. By the early 1990s, much was known about C4 biochemistry, the types of leaf anatomy that facilitated the pathway, and the patterns of gene expression that underpinned the biochemistry. However, virtually nothing was known about how the pathway was regulated. It should have been an exciting time, but many of the original researchers were approaching retirement, C4 plants were proving recalcitrant to genetic manipulation, and whole-genome sequences were not even a dream. In combination, these factors led to reduced funding and the failure to attract young people into the field; the endgame seemed to be underway. But over the last 5 years, there has been a resurgence of interest and funding, not least because of ambitious multinational projects that aim to increase crop yields by introducing C4 traits into C3 plants. Combined with new technologies, this renewed interest has resulted in the development of more sophisticated approaches toward understanding how the C4 pathway evolved, how it is regulated, and how it might be manipulated. The extent of this resurgence is manifest by the publication in 2011 of more than 650 pages of reviews on different aspects of C4. Here, I provide an overview of our current understanding, the questions that are being addressed, and the issues that lie ahead. PMID:22128120

Synthesis, linear and nonlinear optical properties of phosphonato-substituted bithiophenes derived from 2,2'-biphenol.

PubMed

Freeman, Jason L; Zhao, Qun; Zhang, Yuanli; Wang, Jianwei; Lawson, Christopher M; Gray, Gary M

2013-10-21

Two new series of phosphonato-substituted bithiophenes, BpP(X)(C4H2S)2H and BpP(X)(C4H2S)2P(X)Bp (Bp = 2,2'-C12H8O2, X = O, S, Se), have been synthesized and characterized using linear absorption and emission spectra, and third-order nonlinear absorption measurements at 430 nm with 27 ps laser pulses. The compounds were synthesized in three steps: (1) reacting lithiated bithiophene with (Et2N)2PCl; (2) reacting the product from the first step with biphenol; and (3) reacting the product from the second step with the appropriate chalcogen. The X-ray crystal structures of two of the compounds, BpP(O)(C4H2S)2P(O)Bp and BpP(Se)(C4H2S)2P(Se)Bp, are reported and show a number of intermolecular π-π interactions. The linear absorption spectra, emission spectra, and emission quantum yields show distinct trends with respect to the chalcogen and the number of phosphorus substituents attached to the 2,2'-bithiophene ring. The compounds show emission maxima at wavelengths ranging from 380-400 nm and, BpP(S)(C4H2S)2H shows a 23-fold increase in fluorescence quantum yield relative to that of 2,2'-bithiophene. Fluorescence lifetimes and radiative and non-radiative decay rate constants for the first singlet excited state have been extracted from the quantum yields using time-dependent DFT calculations. Nonlinear transmission measurements indicate that all of the compounds show nonlinear absorption at 430 nm with 27 ps laser pulses in spite of their low solubilities. Notably, the nonlinear absorption threshold of a 0.16 mol L(-1) CH2Cl2 solution of BpP(Se)(C4H2S)2H is 0.9 J cm(-2). The excellent emission quantum yields and good nonlinear absorptions make these compounds promising candidates for optical power limiting applications and as host materials for violet-blue organic light emitting diodes.

Synthesis of three new thiophene condensed pyrene derivatives, crystal structure and evaluation of their photophysical properties

NASA Astrophysics Data System (ADS)

Moriguchi, Tetsuji; Yakeya, Daisuke; Tsuge, Akihiko; Jalli, Venkataprasad

2018-04-01

Three new thiophene condensed fluorescent pyrene derivatives have been synthesized by a two-step process, via. Wittig reaction followed by iodine promoted photocyclization. These molecules have been characterized by 1H NMR and EI-MS. Further, the molecular structures of 4a, 4b and 4c has been confirmed by single crystal X-ray diffraction analysis. The protons located in the fjord and cove-regions of molecules 4b and 4c showed downfield shifts of the protons. Molecule 4a crystallized under monoclinic system with space group P21/c, molecule 4b crystallized under monoclinic system with space group C2/c and the molecule 4c crystalized under triclinic system with space group P-1. Molecules 4a, 4b and 4c showed strong absorption maxima wavelengths at 305, 358 and 330 nm, respectively. The molar extinctinction coefficients (ε) of the compounds 4a, 4b and 4c indicated molecule 4c has better ability to absorb UV light, molecule 4b has better fluorescence intensity than molecule 4a and 4c.

Crystal Structure and Magnetic Behavior of Two New Dinuclear Carbonato-Bridged Copper(II) Compounds. Superexchange Pathway for the Different Coordination Modes of the Carbonato Bridge in Polynuclear Copper(II) Compounds.

PubMed

Escuer, Albert; Mautner, Franz A.; Peñalba, Evaristo; Vicente, Ramon

1998-08-24

Four new &mgr;-CO(3)(2-) copper(II) complexes with different coordination modes for the carbonato bridge have been obtained by fixation of atmospheric CO(2): {(&mgr;(3)-CO(3))[Cu(3)(ClO(4))(3)(Et(3)dien)(3)]}(ClO(4)) (1), Et(3)dien = N,N',N"-triethylbis(2-aminoethane)amine; {(&mgr;-CO(3))[Cu(2)(H(2)O)(Et(4)dien)(2)]}(ClO(4))(2).H(2)O (2), Et(4)dien = N,N,N",N"-tetraethyl-bis(2-aminoethane)amine; {(&mgr;-CO(3))[Cu(2)(H(2)O)(2)(EtMe(4)dien)(2)]} (ClO(4))(2).2H(2)O (3), EtMe(4)dien = N'-ethyl-N,N,N",N"-tetramethylbis(2-aminoethane)amine; and {(&mgr;-CO(3))[Cu(2)(H(2)O)(Me(5)dien)(2)]}(ClO(4))(2).H(2)O (4), Me(5)dien = N,N,N',N",N"-pentamethylbis(2-aminoethane)amine. The crystal structures have been solved for 2, monoclinic system, space group P2(1)/n, formula [C(25)H(62)Cl(2)Cu(2)N(6)O(13)] with a = 12.763(6) Å, b = 25.125(8) Å, c = 13.261(4) Å, beta = 111.85(3) degrees, Z = 4, and for 3, triclinic system, space group P&onemacr;, formula [C(21)H(58)Cl(2)Cu(2)N(6)O(15)] with a = 8.412(3) Å, b = 14.667(4) Å, c = 16.555(5) Å, alpha = 99.66(2) degrees, beta = 102.14(2) degrees, gamma = 104.72(2) degrees, Z = 2. Susceptibility measurements show ferromagnetic behavior (J = +6.7(6) cm(-)(1)) for the trinuclear compound 1 whereas 2-4 are antiferromagnetically coupled with J = -17.8(8), -125.5(9), and -21.2(3) cm(-)(1) respectively. Certain synthetic aspects that may be related to the nuclearity of the copper(II) &mgr;-CO(3)(2-) compounds and the superexchange pathway for the different coordination modes of the carbonato bridge are discussed.

Synthesis of a Pilot Scale Library of 4-amino-2 (diethylaminomethyl) phenol (ADOC) Analogues for Testing of Organophosphate-Inhibited Acetylcholinesterase Reactivation Ability

DTIC Science & Technology

2018-02-01

deacetylation under acidic conditions worked poorly (discussed below). We were happy to find that boc-protected phenol 5 provided access to the title compounds...intermediate 5, which we were happy to discover was easily elaborated to furnish the desired compounds. Scheme 4. Synthesis of benzylamino analogs 6a-c. 4

N1-Nonyl-1,4-diaminobutane ameliorates brain infarction size in photochemically induced thrombosis model mice.

PubMed

Masuko, Takashi; Takao, Koichi; Samejima, Keijiro; Shirahata, Akira; Igarashi, Kazuei; Casero, Robert A; Kizawa, Yasuo; Sugita, Yoshiaki

2018-04-13

Inhibitors for polyamine oxidizing enzymes, spermine oxidase (SMOX) and N 1 -acetylpolyamine oxidase (PAOX), were designed and evaluated for their effectiveness in a photochemically induced thrombosis (PIT) mouse model. N 1 -Nonyl-1,4-diaminobutane (C9-4) and N 1 -tridecyl-1,4-diaminobutane (C13-4) competitively inhibited the activity of PAOX and SMOX in a manner comparable to N 1 ,N 4 -bis(2,3-butadienyl)-1,4-butanediamine (MDL72527), an irreversible inhibitor of both enzymes. The two compounds were then tested for their effects in the PIT model. Both intraperitoneal (i.p.) and intracerebroventricular (i.c.v.) administration of C9-4 decreased infarct volumes significantly. By contrast, C13-4 reduced the volume of brain infarction by i.c.v. administration, but no reduction was observed after i.p. administration. C9-4 administered by i.p. injection reduced the volume of brain infarction significantly at doses of more than 3 mg/kg, and the dosage of 5 mg/kg or 10 mg/kg demonstrated the most potent effect and were more effective than equivalent doses of the other inhibitors such as MDL72527 and N-benzylhydroxylamine. I.P. injection of 5 mg/kg of C9-4 provided a therapeutic time window of longer than 12 h. This report demonstrates that C9-4 is a potent inhibitor of the polyamine oxidizing enzymes and is useful lead compound for candidate drugs with a long therapeutic time window, to be used in the treatment of ischemic stroke. Copyright © 2018 Elsevier B.V. All rights reserved.

Synthesis, characterization and optical properties of NH4Dy(PO3)4

NASA Astrophysics Data System (ADS)

Chemingui, S.; Ferhi, M.; Horchani-Naifer, K.; Férid, M.

2014-09-01

Polycrystalline powders of NH4Dy(PO3)4 polyphosphate have been grown by the flux method. This compound was found to be isotopic with NH4Ce(PO3)4 and RbHo(PO3)4. It crystallizes in the monoclinic space group P21/n with unit cell parameters a=10.474(6) Å, b=9.011(4) Å, c=10.947(7) Å and β=106.64(3)°. The title compound has been transformed to triphosphate Dy(PO3)3 after calcination at 800 °C. Powder X-ray diffraction, infrared and Raman spectroscopies and the differential thermal analysis have been used to identify these materials. The spectroscopic properties have been investigated through absorption, excitation, emission spectra and decay curves of Dy3+ ion in both compounds at room temperature. The emission spectra show the characteristic emission bands of Dy3+ in the two compounds, before and after calcination. The integrated emission intensity ratios of the yellow to blue (IY/IB) transitions and the chromaticity properties have been determined from emission spectra. The decay curves are found to be double-exponential. The non-exponential behavior of the decay rates was related to the resonant energy transfer as well as cross-relaxation between the donor and acceptor Dy3+ ions. The determined properties have been discussed as function of crystal structure of both compounds. They reveal that NH4Dy(PO3)4 is promising for white light generation but Dy(PO3)3 is potential candidates in field emission display (FED) and plasma display panel (PDP) devices.

Three polymorphs of an inclusion compound of 2,2'-(disulfanediyl)dibenzoic acid and trimethylamine.

PubMed

Yang, Yunxia; Li, Lihua; Zhang, Li; Dong, Wenjing; Ding, Keying

2016-12-01

Polymorphism is the ability of a solid material to exist in more than one form or crystal structure and this is of interest in the fields of crystal engineering and solid-state chemistry. 2,2'-(Disulfanediyl)dibenzoic acid (also called 2,2'-dithiosalicylic acid, DTSA) is able to form different hydrogen bonds using its carboxyl groups. The central bridging S atoms allow the two terminal arene rings to rotate freely to generate various hydrogen-bonded linking modes. DTSA can act as a potential host molecule with suitable guest molecules to develop new inclusion compounds. We report here the crystal structures of three new polymorphs of the inclusion compound of DTSA and trimethylamine, namely trimethylazanium 2-[(2-carboxyphenyl)disulfanyl]benzoate 2,2'-(disulfanediyl)dibenzoic acid monosolvate, C 3 H 10 N + ·C 14 H 9 O 4 S 2 - ·C 14 H 10 O 4 S 2 , (1), tetrakis(trimethylazanium) bis{2-[(2-carboxyphenyl)disulfanyl]benzoate} 2,2'-(disulfanediyl)dibenzoate 2,2'-(disulfanediyl)dibenzoic acid monosolvate, 4C 3 H 10 N + ·2C 14 H 9 O 4 S 2 - ·C 14 H 8 O 4 S 2 2- ·C 14 H 10 O 4 S 2 , (2), and trimethylazanium 2-[(2-carboxyphenyl)disulfanyl]benzoate, C 3 H 10 N + ·C 14 H 9 O 4 S 2 - , (3). In the three polymorphs, DTSA utilizes its carboxyl groups to form conventional O-H...O hydrogen bonds to generate different host lattices. The central N atoms of the guest amine molecules accept H atoms from DTSA molecules to give the corresponding cations, which act as counter-ions to produce the stable crystal structures via N-H...O hydrogen bonding between the host acid and the guest molecule. It is noticeable that although these three compounds are composed of the same components, the final crystal structures are totally different due to the various configurations of the host acid, the number of guest molecules and the inducer (i.e. ancillary experimental acid).

Synthesis, structural elucidation and pharmacological properties of some 5-acetyl-3,4-dihydro-6-methyl-4-(substituted phenyl)-2(1H) -pyrimidinones.

PubMed

Yarim, M; Sarac, S; Ertan, M; Batu, O S; Erol, K

1999-06-30

In this study, the synthesis of some new 5-acetyl-3,4-dihydro-6-methyl-4-(substituted phenyl)-2(1H)-pyrimidinones has been reported. The compounds were prepared by the Biginelli reaction of acetylacetone with aromatic aldehydes and urea. The structures of the compounds were characterized by UV, IR, 1H NMR, 13C NRM, mass spectra and elementary analysis. The calcium antagonistic activity of these compounds was tested in vitro on rat ileum precontracted with 4 x 10(-3) M barium chloride.

Jumpstarting the cytochrome P450 catalytic cycle with a hydrated electron.

PubMed

Erdogan, Huriye; Vandemeulebroucke, An; Nauser, Thomas; Bounds, Patricia L; Koppenol, Willem H

2017-12-29

Cytochrome P450cam (CYP101Fe 3+ ) regioselectively hydroxylates camphor. Possible hydroxylating intermediates in the catalytic cycle of this well-characterized enzyme have been proposed on the basis of experiments carried out at very low temperatures and shunt reactions, but their presence has not yet been validated at temperatures above 0 °C during a normal catalytic cycle. Here, we demonstrate that it is possible to mimic the natural catalytic cycle of CYP101Fe 3+ by using pulse radiolysis to rapidly supply the second electron of the catalytic cycle to camphor-bound CYP101[FeO 2 ] 2+ Judging by the appearance of an absorbance maximum at 440 nm, we conclude that CYP101[FeOOH] 2+ (compound 0) accumulates within 5 μs and decays rapidly to CYP101Fe 3+ , with a k 440 nm of 9.6 × 10 4 s -1 All processes are complete within 40 μs at 4 °C. Importantly, no transient absorbance bands could be assigned to CYP101[FeO 2+ por •+ ] (compound 1) or CYP101[FeO 2+ ] (compound 2). However, indirect evidence for the involvement of compound 1 was obtained from the kinetics of formation and decay of a tyrosyl radical. 5-Hydroxycamphor was formed quantitatively, and the catalytic activity of the enzyme was not impaired by exposure to radiation during the pulse radiolysis experiment. The rapid decay of compound 0 enabled calculation of the limits for the Gibbs activation energies for the conversions of compound 0 → compound 1 → compound 2 → CYP101Fe 3+ , yielding a Δ G ‡ of 45, 39, and 39 kJ/mol, respectively. At 37 °C, the steps from compound 0 to the iron(III) state would take only 4 μs. Our kinetics studies at 4 °C complement the canonical mechanism by adding the dimension of time. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Application of LC-MS analysis to the characterisation of the in vitro and in vivo metabolite profiles of RGH-1756 in the rat.

PubMed

Gémesi, L I; Kapás, M; Szeberényi, S

2001-03-01

RGH-1756, 1-(2-methoxy-phenyl)-4-(4-[4-(6-imidazol[2,1-b] thiazolyl)-phenoxy]-butyl-4-(14)C)-piperazine dimethane is a novel atypical antipsychotic drug candidate of Gedeon Richter Ltd. The metabolic pathways of the compound have been investigated by profiling the metabolites present in plasma, bile, and faeces samples of rats treated with (14)C-RGH-1756. The metabolites formed in vitro by rat liver microsomes have also been analysed. Good separation of the compounds has been achieved by gradient HPLC method on Zorbax/Bonus RP-C18 column. Radiometry and mass spectrometry have been applied to detect and characterise the metabolites. The metabolite formed by oxidative cleavage of the chain at the carbon atom adjacent to the piperazine nitrogen has been identified as the major plasma metabolite. Glucuronide conjugate of hydroxy-RGH-1756 has been found as one of the main metabolites excreted in the bile where the unchanged compound has not been detected.

K(2)MM'(3)Se(6) (M = Cu, Ag; M' = Ga, In), A new series of metal chalcogenides with chain-sublayer-chain slabs: (infinity)(1)[M'Se(4)]-(infinity)(2)[(MSe(4))(M'Se(4))]-(infinity)(1)[M'Se(4)].

PubMed

Ma, Hong-Wei; Guo, Guo-Cong; Wang, Ming-Sheng; Zhou, Guo-Wei; Lin, Shan-Hou; Dong, Zhen-Chao; Huang, Jin-Shun

2003-02-24

A new series of novel isostructural metal chalcogenides, K(2)CuIn(3)Se(6) (1), K(2)CuGa(3)Se(6) (2), and K(2)AgIn(3)Se(6) (3), were obtained by a reactive flux technique and structurally characterized. Compounds 1, 2, and 3 crystallize in the space group C2/c of the monoclinic system with eight formula units in a cell: a = 11.445(2) A, b = 11.495(2) A, c = 21.263(4) A, beta = 97.68(3) degrees, V = 2772(1) A(3), R1/wR2 = 0.0676/0.1652 for 1; a = 11.031(2) A, b = 11.050(4) A, c = 20.808(7) A, beta = 97.71(2) degrees, V = 2513(1) A(3), R1/wR2 = 0.0301/0.0511 for 2; and a = 11.633(1) A, b = 11.587(1) A, c = 21.355(1) A, beta = 98.010(8) degrees, V = 2850.4(4) A(3), R1/wR2 = 0.0471/0.0732 for 3. These isostructural compounds are characterized by a chain-sublayer-chain slab structure. The sublayer, composed of alternative corner-sharing mixed-metal tetrahedra, is sandwiched by parallel corner-sharing tetrahedral chains. Optical absorption spectra of compounds 1, 2, and 3 reveal the presence of a sharp optical gap of 1.68, 1.72, and 1.64 eV, respectively, suggesting that these materials are semiconductors and suitable for efficient absorption of solar radiation in solar cell applications. IR spectra show no obvious absorption in the range 800-4000 cm(-)(1).

Azo compounds as a family of organic electrode materials for alkali-ion batteries.

PubMed

Luo, Chao; Borodin, Oleg; Ji, Xiao; Hou, Singyuk; Gaskell, Karen J; Fan, Xiulin; Chen, Ji; Deng, Tao; Wang, Ruixing; Jiang, Jianjun; Wang, Chunsheng

2018-02-27

Organic compounds are desirable for sustainable Li-ion batteries (LIBs), but the poor cycle stability and low power density limit their large-scale application. Here we report a family of organic compounds containing azo group (N=N) for reversible lithiation/delithiation. Azobenzene-4,4'-dicarboxylic acid lithium salt (ADALS) with an azo group in the center of the conjugated structure is used as a model azo compound to investigate the electrochemical behaviors and reaction mechanism of azo compounds. In LIBs, ADALS can provide a capacity of 190 mAh g -1 at 0.5 C (corresponding to current density of 95 mA g -1 ) and still retain 90%, 71%, and 56% of the capacity when the current density is increased to 2 C, 10 C, and 20 C, respectively. Moreover, ADALS retains 89% of initial capacity after 5,000 cycles at 20 C with a slow capacity decay rate of 0.0023% per cycle, representing one of the best performances in all organic compounds. Superior electrochemical behavior of ADALS is also observed in Na-ion batteries, demonstrating that azo compounds are universal electrode materials for alkali-ion batteries. The highly reversible redox chemistry of azo compounds to alkali ions was confirmed by density-functional theory (DFT) calculations. It provides opportunities for developing sustainable batteries.

Functionalization of P4 through Direct P-C Bond Formation.

PubMed

Borger, Jaap E; Ehlers, Andreas W; Slootweg, J Chris; Lammertsma, Koop

2017-09-04

Research on chlorine-free conversions of P 4 into organophosphorus compounds (OPCs) has a long track record, but methods that allow desirable, direct P-C bond formations have only recently emerged. These include the use of metal organyls, carbenes, carboradicals, and photochemical approaches. The versatile product scope enables the preparation of both industrially relevant organophosphorus compounds, as well as a broad range of intriguing new compound classes. Herein we provide a concise overview of recent breakthroughs and outline the acquired fundamental insights to aid future developments. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of 4-hydroxy-3-methylchalcone from Reimer-Tiemann reaction product and its antibacterial activity test

NASA Astrophysics Data System (ADS)

Hapsari, M.; Windarti, T.; Purbowatiningrum; Ngadiwiyana; Ismiyarto

2018-04-01

A 4-hydroxy-3-methylchalcone has been synthesized from 4-hydroxy-3-methylbenzaldehyde as the Reimer-Tiemann reaction product. This research consists of three steps involve synthesize of 4-hydroxy-3-methylbenzaldehyde from ortho-cresol, synthesize of chalcone derivatives from 4-hydroxy-3-methylbenzaldehyde and 4-hydroxy-3-methoxybenzaldehyde or vanillin for the comparison, the last is antibacterial activity test of both chalcone derivatives against Escherichia coli (negative gram) and Staphylococcus aureus (positive gram) bacteria using disc diffusion method. Results of Reimer-Tiemann reaction is 4-hydroxy-3-methylbenzaldehyde compound in an orange colour solid form which has 43% yields and melting point 110-114°C. A 4-hydroxy-3-methylbenzaldehyde then reacted with acetophenone in a base condition and form 4-hydroxy-3-methylchalcone compound in a yellow colour solid form which has 40% yields and melting point 83-86°C. The antibacterial activity of the 4-hydroxy-3-methylchalcone against gram-positive bacteria Staphylococcus aureus is better than the 4-hydroxy-3-methoxychalcone.

Thiazole-based nitrogen mustards: Design, synthesis, spectroscopic studies, DFT calculation, molecular docking, and antiproliferative activity against selected human cancer cell lines

NASA Astrophysics Data System (ADS)

Łączkowski, Krzysztof Z.; Świtalska, Marta; Baranowska-Łączkowska, Angelika; Plech, Tomasz; Paneth, Agata; Misiura, Konrad; Wietrzyk, Joanna; Czaplińska, Barbara; Mrozek-Wilczkiewicz, Anna; Malarz, Katarzyna; Musioł, Robert; Grela, Izabela

2016-09-01

Synthesis, characterization and investigation of antiproliferative activity of ten thiazole-based nitrogen mustard against human cancer cells lines (MV4-11, A549, MCF-7 and HCT116) and normal mouse fibroblast (BALB/3T3) is presented. The structures of novel compounds were determined using 1H and 13C NMR, FAB(+)-MS, and elemental analyses. Among the derivatives, 5b, 5c, 5e, 5f and 5i were found to exhibit high activity against human leukaemia MV4-11 cells with IC50 values of 2.17-4.26 μg/ml. The cytotoxic activity of compound 5c and 5f against BALB/3T3 cells is up to 20 times lower than against cancer cell lines. Our results also show that compounds 5e and 5i have very strong activity against MCF-7 and HCT116 with IC50 values of 3.02-4.13 μg/ml. Moreover, spectroscopic characterization and cellular localization for selected compound were performed. In order to identify potential drug targets we perform computer simulations with DNA-binding site of hTopoI and hTopoII and quantum chemical calculation of interaction and binding energies in complexes of the five most active compounds with guanine.

Changes in ambient temperature differentially alter the thermoregulatory, cardiac and locomotor stimulant effects of 4-methylmethcathinone (mephedrone).

PubMed

Miller, M L; Creehan, K M; Angrish, D; Barlow, D J; Houseknecht, K L; Dickerson, T J; Taffe, M A

2013-01-01

The substituted cathinone compound known as mephedrone (4-methylmethcathinone; 4-MMC) has become popular with recreational users of psychomotor-stimulant compounds. Only recently have the first preclinical studies provided information about this drug in the scientific literature; nevertheless, media reports have led to drug control actions in the UK and across several US states. Rodent studies indicate that 4-MMC exhibits neuropharmacological similarity to 3,4-methylenedioxymethamphetamine (MDMA) and prompt investigation of the thermoregulatory, cardiac and locomotor effects of 4-MMC. This study focuses on the role of ambient temperature, which has been shown to shift the effects of MDMA from hyperthermic to hypothermic. Male Sprague-Dawley rats were monitored after subcutaneous administration of 4-MMC (1.0-5.6 mg/kg) using an implantable radiotelemetry system under conditions of low (20 °C) and high (30 °C) ambient temperature. A pharmacokinetic study found a T(max) of 0.25 h and a C(max) of 1206 ng/ml after 5.6 mg/kg 4-MMC. A dose-dependent reduction of body temperature was produced by 4-MMC at 20 °C but there was no temperature change at 30 °C. Increased locomotor activity was observed after 4-MMC administration under both ambient temperatures, however, significantly more activity was observed at 30 °C. Heart rate was slowed by 1.0 and 5.6 mg/kg 4-MMC at 20°C, and was slower in the 30 °C vs. 20 °C condition across all treatments. These results show that the cathinone analog 4-MMC exhibits in vivo thermoregulatory properties that are distinct from those produced by MDMA. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Preparation of dibenzo[e,g]isoindol-1-ones via Scholl-type oxidative cyclization reactions.

PubMed

van Loon, Amy A; Holton, Maeve K; Downey, Catherine R; White, Taryn M; Rolph, Carly E; Bruening, Stephen R; Li, Guanqun; Delaney, Katherine M; Pelkey, Sarah J; Pelkey, Erin T

2014-09-05

A flexible synthesis of dibenzo[e,g]isoindol-1-ones has been developed. Dibenzo[e,g]isoindol-1-ones represent simplified benzenoid analogues of biological indolo[2,3-a]pyrrolo[3,4-c]carbazol-5-ones (indolocarbazoles), compounds that have demonstrated a wide range of biological activity. The synthesis of the title compounds involved tetramic acid sulfonates. Different aryl groups were introduced at C4 of the heterocyclic ring via Suzuki-Miyaura cross-coupling reactions. Finally, mild Scholl-type oxidative cyclizations mediated by phenyliodine(III) bis(trifluoroacetate) (PIFA) converted some of the latter compounds into the corresponding dibenzo[e,g]isoindol-1-ones. A systematic study of the oxidative cyclization revealed the following reactivity trend: 3,4-dimethoxyphenyl ≫ 3-methoxyphenyl > 3,4,5-trimethoxyphenyl > 4-methoxyphenyl ≈ phenyl. Overall, the oxidative cyclization required at least two methoxy groups distributed in the aromatic rings, at least one of which had to be located para to the site of the cyclization.

Preparation of Dibenzo[e,g]isoindol-1-ones via Scholl-Type Oxidative Cyclization Reactions

PubMed Central

2015-01-01

A flexible synthesis of dibenzo[e,g]isoindol-1-ones has been developed. Dibenzo[e,g]isoindol-1-ones represent simplified benzenoid analogues of biological indolo[2,3-a]pyrrolo[3,4-c]carbazol-5-ones (indolocarbazoles), compounds that have demonstrated a wide range of biological activity. The synthesis of the title compounds involved tetramic acid sulfonates. Different aryl groups were introduced at C4 of the heterocyclic ring via Suzuki–Miyaura cross-coupling reactions. Finally, mild Scholl-type oxidative cyclizations mediated by phenyliodine(III) bis(trifluoroacetate) (PIFA) converted some of the latter compounds into the corresponding dibenzo[e,g]isoindol-1-ones. A systematic study of the oxidative cyclization revealed the following reactivity trend: 3,4-dimethoxyphenyl ≫ 3-methoxyphenyl > 3,4,5-trimethoxyphenyl > 4-methoxyphenyl ≈ phenyl. Overall, the oxidative cyclization required at least two methoxy groups distributed in the aromatic rings, at least one of which had to be located para to the site of the cyclization. PMID:25138638

New molecular assemblies of redox isomers, [CrIII(X4SQ)3-n(X4Cat)n]-n (X = Cl and Br; n = 0, 1, and 2), with metallocenium cations, [MIIICp2]+ (M = Co and Fe): X-ray crystal structures and physical properties.

PubMed

Chang, H C; Miyasaka, H; Kitagawa, S

2001-01-01

A series of redox isomers of [CrIII(X4SQ)(X4Cat)2]2-, [CrIII(X4SQ)2(X4Cat)]-, and [CrIII(X4SQ)3]0 (X = Cl and Br, SQ = semiquinonate, and Cat = catecholate) have been synthesized and characterized as charge-transfer (CT) compounds with metallocenium cations: (CoIIICp2)2[CrIII(Cl4SQ)(Cl4Cat)2] (1), (CoIIICp2)2[CrIII(Br4SQ)(Br4Cat)2] (2), (FeIIICp2)[CrIII(Cl4SQ)2(Cl4Cat)].C6H6 (4), (FeIIICp2)[CrIII(Br4SQ)2(Br4Cat)].CS2 (5), and (FeIIICp2)[CrIII(Cl4SQ)2(Cl4Cat)][CrIII(Cl4SQ)3] (6). First, the oxidation states of the chromium complexes are strongly dependent on the redox potentials of the metallocenes used. The CoIICp2, exhibiting stronger reduction power than FeIICp2, is useful for two-electron reduction of the [CrIII(X4SQ)3]0, affording [CrIII(X4SQ)(X4Cat)2]2- (1 and 2), which are first isolated and crystallographically characterized in the solid state. In contrast the reaction with FeIICp2 affords only [CrIII(X4SQ)2(X4Cat)]- (4 and 5). Second, solvents influence crystal structures of these compounds. The solvent set of C6H6/CS2 gives 1:1:C6H6 compound 4 with unique charged anions, [CrIII(Cl4SQ)2(Cl4Cat)]-, while the other set, n-C6H12/CS2, affords 1:2 compound 6 including the two redox isomers, [CrIII(Cl4SQ)2(Cl4Cat)]- and [CrIII(Cl4SQ)3]0. The [CrIII(X4SQ)(X4Cat)2]2- anions in 1 and 2 show no significant interconnection between them (discrete type), while the [CrIII(X4SQ)2(X4Cat)]- anions in 4-6 show one-dimensional column-type structures with the aid of intermolecular stacking interactions of the ligand moieties. The anions in 4 show additional stacking interaction with the [FeIIICp2]+ to form one-dimensional ...[D][A][S][D][A]... (D = [FeIIICp2]+, A = [CrIII(Cl4SQ)2(Cl4Cat)]-, and S = C6H6) type mixed-stack arrangements similar to that of previously reported (CoIIICp2)[CrIII(Cl4SQ)2(Cl4Cat)].C6H6 (3). Compound 6 forms a two-dimensional sheet structure where the two redox isomers, [CrIII(Cl4SQ)2(Cl4Cat)]- and [CrIII(Cl4SQ)3]0, are included. The sheet is regarded as a mixed-valence molecular assembly. Two types of the anions, [CrIII(X4SQ)(X4Cat)2]2- (1 and 2) and [CrIII(X4SQ)2(X4Cat)]- (4-6), exhibiting an intramolecular mixed-valence state, show intramolecular intervalence CT transition (IVCT) from the Cat to the SQ at near 5800 and 4300 cm-1, respectively, both in the solution and in the solid states. The intermolecular mixed-valence state of 6 was characterized by absorption spectroscopy, electric conductivity, and SQUID magnetometry. Interestingly, this mixed-valence state of the chromium module is dependent on the redox active nature of the coordinated ligands.

Synthesis and evaluation of 4',5'-dihydrospiro[piperidine-4,7'-thieno[2,3-c]pyran] analogues against both active and dormant Mycobacterium tuberculosis.

PubMed

Alluri, Kiran Kumar; Reshma, Rudraraju Srilakshmi; Suraparaju, Raghuram; Gottapu, Suryanarayana; Sriram, Dharmarajan

2018-05-01

Need for new drugs to fight against tuberculosis (TB) is increasing day by day. In the present work we have taken a spiro compound (GSK 2200150A) reported by GSK as a lead and we modified the structure of the lead to study the antitubercular activity. For structure activity profiling twenty-one molecules have been synthesized, characterized and evaluated for their antimycobacterial potency against both active and dormant TB. Compound 06, 1-((4-methoxyphenyl)sulfonyl)-4',5'-dihydrospiro[piperidine-4,7'-thieno[2,3-c]pyran] was found to be the most potent compound (MIC: 8.23 µM) in active TB and was less effective than the lead but more potent than standard first line drug ethambutol. It was also found to be more efficacious than Isoniazid and Rifampicin and equipotent as Moxifloxacin against dormant Mycobacterium tuberculosis (MTB). Compound 06 also showed good inhibitory potential against over expressed latent MTB enzyme lysine ε-amino transferase with an IC 50 of 1.04 ± 0.32 µM. This compound is a good candidate for drug development owing to potential against both active and dormant stages of MTB. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ganoboninketals A-C, Antiplasmodial 3,4-seco-27-Norlanostane Triterpenes from Ganoderma boninense Pat.

PubMed

Ma, Ke; Ren, Jinwei; Han, Junjie; Bao, Li; Li, Li; Yao, Yijian; Sun, Chen; Zhou, Bing; Liu, Hongwei

2014-08-22

Three new nortriterpenes, ganoboninketals A-C (1-3), featuring rearranged 3,4-seco-27-norlanostane skeletons and highly complex polycyclic systems were isolated from the medicinal mushroom Ganoderma boninense. The structures of the new metabolites were established by spectroscopic methods. The absolute configurations in 1-3 were assigned by electronic circular dichroism (ECD) calculations. Compounds 1-3 showed antiplasmodial activity against Plasmodium falciparum with IC50 values of 4.0, 7.9, and 1.7 μM, respectively. Compounds 1 and 3 also displayed weak cytotoxicity against A549 cell line with IC50 values of 47.6 and 35.8 μM, respectively. Compound 2 showed weak cytotoxicity toward HeLa cell line with an IC50 value of 65.5 μM. Compounds 1-3 also presented NO inhibitory activity in the LPS-induced macrophages with IC50 values of 98.3, 24.3, and 60.9 μM, respectively.

Structure-activity relationships of truncated C2- or C8-substituted adenosine derivatives as dual acting A₂A and A₃ adenosine receptor ligands.

PubMed

Hou, Xiyan; Majik, Mahesh S; Kim, Kyunglim; Pyee, Yuna; Lee, Yoonji; Alexander, Varughese; Chung, Hwa-Jin; Lee, Hyuk Woo; Chandra, Girish; Lee, Jin Hee; Park, Seul-Gi; Choi, Won Jun; Kim, Hea Ok; Phan, Khai; Gao, Zhan-Guo; Jacobson, Kenneth A; Choi, Sun; Lee, Sang Kook; Jeong, Lak Shin

2012-01-12

Truncated N(6)-substituted-4'-oxo- and 4'-thioadenosine derivatives with C2 or C8 substitution were studied as dual acting A(2A) and A(3) adenosine receptor (AR) ligands. The lithiation-mediated stannyl transfer and palladium-catalyzed cross-coupling reactions were utilized for functionalization of the C2 position of 6-chloropurine nucleosides. An unsubstituted 6-amino group and a hydrophobic C2 substituent were required for high affinity at the hA(2A)AR, but hydrophobic C8 substitution abolished binding at the hA(2A)AR. However, most of synthesized compounds displayed medium to high binding affinity at the hA(3)AR, regardless of C2 or C8 substitution, and low efficacy in a functional cAMP assay. Several compounds tended to be full hA(2A)AR agonists. C2 substitution probed geometrically through hA(2A)AR docking was important for binding in order of hexynyl > hexenyl > hexanyl. Compound 4g was the most potent ligand acting dually as hA(2A)AR agonist and hA(3)AR antagonist, which might be useful for treatment of asthma or other inflammatory diseases.

Volatile organic compound measurements in the California/Mexico border region during SCOS97

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zielinska, B.; Sagebiel, J.; Uberna, E.

1999-07-01

Measurements of volatile organic compounds (VOC) were carried out in the California/Mexico border region during the Southern California Ozone study in the Summer of 1997 (SCOS97). Integrated 3-hr samples were collected in Rosarito (south of Tijuana, Mexico) and in Mexicali during Intensive Operational Periods (IOP), twice per IOP day. VOC were collected using stainless-steel 6 L canisters; carbonyl compounds were collected using 2,4-dinitrophenylhydrazine (DNPH) impregnated C{sub 18} SepPak cartridges. The canister samples were analyzed for speciated volatile hydrocarbons (C{sub 2}-C{sub 12}), CO, CO{sub 2}, CH{sub 4}, MTBE, and halogenated hydrocarbons. DNPH-impregnated cartridges were analyzed for fourteen C{sub 1}-C{sub 7} carbonylmore » compounds. The results of these measurements will be discussed.« less

Peculiarities of the crystal structure of modified banana-shaped mesogen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zharova, M. A.; Usol'tseva, N. V., E-mail: nadezhda_usoltseva@yahoo.com; Ungar, G.

The structure and phase behavior of an achiral banana-shaped compound-bis-{l_brace}3,4,5-tri[4-(4-n-nonyloxybenzoyloxy)] benzoylamino{r_brace}-1,3-phenylene (I)-have been investigated. This compound exhibits an enantiotropic high-temperature chiral mesophase; upon cooling it successively passes to the crystalline (Cr) phases: Cr{alpha} (281.0-176.0 deg. C), Cr{beta} (175.0-72.0 deg. C), and Cr{gamma} (71.0-40.0 deg. C) (their temperature ranges of existence are indicated). The surface topology and results of linear measurements along the cross sections of certain portions of thin films of compound I in the Cr {gamma} phase clearly prove the effect of the preserved chirality of the previous liquid-crystal phase in the crystalline state.

Structure-Activity Relationships of Truncated C2- or C8-Substituted Adenosine Derivatives as Dual Acting A2A and A3 Adenosine Receptor Ligands

PubMed Central

Hou, Xiyan; Majik, Mahesh S.; Kim, Kyunglim; Pyee, Yuna; Lee, Yoonji; Alexander, Varughese; Chung, Hwa-Jin; Lee, Hyuk Woo; Chandra, Girish; Lee, Jin Hee; Park, Seul-gi; Choi, Won Jun; Kim, Hea Ok; Phan, Khai; Gao, Zhan-Guo; Jacobson, Kenneth A.; Choi, Sun; Lee, Sang Kook; Jeong, Lak Shin

2011-01-01

Truncated N6-substituted-4′-oxo- and 4′-thioadenosine derivatives with C2 or C8 substitution were studied as dual acting A2A and A3 adenosine receptor (AR) ligands. The lithiation-mediated stannyl transfer and palladium-catalyzed cross coupling reactions were utilized for functionalization of the C2 position of 6-chloropurine nucleosides. An unsubstituted 6-amino group and a hydrophobic C2 substituent were required for high affinity at the hA2AAR, but hydrophobic C8 substitution abolished binding at the hA2AAR. However, most of synthesized compounds displayed medium to high binding affinity at the hA3AR, regardless of C2 or C8 substitution, and low efficacy in a functional cAMP assay. Several compounds tended to be full hA2AAR agonists. C2 substitution probed geometrically through hA2AAR-docking, was important for binding in order of hexynyl > hexenyl > hexanyl. Compound 4g was the most potent ligand acting dually as hA2AAR agonist and hA3AR antagonist, which might be useful for treatment of asthma or other inflammatory diseases. PMID:22142423

Methods for labeling .beta.-amyloid plaques and neurofibrillary tangles

DOEpatents

Barrio, Jorge R.; Petric, Andrej; Satyamurthy, Nagichettiar; Small, Gary W.; Cole, Gregory M.; Huang, Sung-Cheng

2003-12-09

A method for labeling .beta.-amyloid plaques and neurofibrillary tangles in vivo and in vitro, comprises contacting a compound of formula (I): ##STR1## with mammalian tissue. In formula (I), R.sub.1 is selected from the group consisting of --C(O)-alkyl, --C(O)-alkylenyl-R.sub.4, --C(O)O-alkyl, --C(O)O-alkylenyl-R.sub.4, --C.dbd.C(CN).sub.2 -alkyl, --C.dbd.C(CN).sub.2 -alkylenyl-R.sub.4, ##STR2## R.sub.4 is a radical selected from the group consisting of alkyl, substituted alkyl, aryl and substituted aryl; R.sub.5 is a radical selected from the group consisting of --NH.sub.2, --OH, --SH, --NH-alkyl, --NHR.sub.4, --NH-alkylenyl-R.sub.4, --O-alkyl, --O-alkylenyl-R.sub.4, --S-alkyl, and --S-alkylenyl-R.sub.4 ; R.sub.6 is a radical selected from the group consisting of --CN, --COOH, --C(O)O-alkyl, --C(O)O-alkylenyl-R.sub.4, --C(O)-alkyl, --C(O)-alkylenyl-R.sub.4, --C(O)-halogen, --C(O)NH, --C(O)NH-alkyl, --C(O)NH-alkylenyl-R.sub.4 ; R.sub.7 is a radical selected from the group consisting of O, NH, and S; and R.sub.8 is N, O or S. R.sub.2 and R.sub.3 are each independently selected from the group consisting of alkyl and alkylenyl-R.sub.10, wherein R.sub.10 is selected from the group consisting of --OH, --OTs, halogen, spiperone, spiperone ketal and spiperone-3-yl. Alternatively, R.sub.2 and R.sub.3 together form a heterocyclic ring, optionally substituted with at least one radical selected from the group consisting of alkyl, alkoxy, OH, OTs, halogen, alkylenyl-R.sub.10, carbonyl, spiperone, spiperone ketal and spiperone-3-yl. In the compounds of formula (I), one or more of the hydrogen, halogen or carbon atoms can, optionally, be replaced with a radiolabel.

Methods for labeling .beta.-amyloid plaques and neurofibrillary tangles

DOEpatents

Barrio, Jorge R.; Petric, Andrej; Satyamurthy, Nagichettiar; Small, Gary W.; Cole, Gregory M.; Huang, Sung-Cheng

2001-01-01

A method for labeling .beta.-amyloid plaques and neurofibrillary tangles in vivo and in vitro, comprises contacting a compound of formula (I): ##STR1## with mammalian tissue. In formula (I), R.sub.1 is selected from the group consisting of --C(O)-alkyl, --C(O)-alkylenyl-R.sub.4, --C(O)O-alkyl, --C(O)O-alkylenyl-R.sub.4, --C.dbd.C(CN).sub.2 -alkyl, --C.dbd.C(CN).sub.2 -alkylenyl-R.sub.4 , ##STR2## R.sub.4 is a radical selected from the group consisting of alkyl, substituted alkyl, aryl and substituted aryl; R.sub.5, is a radical selected from the group consisting of --NH.sub.2, --OH, --SH, --NH-alkyl, --NHR.sub.4, --NH-alkylenyl-R.sub.4, --O-alkyl, --O-alkylenyl-R.sub.4, --S-alkyl, and --S-alkylenyl-R.sub.4 ; R.sub.6 is a radical selected from the group consisting of --CN, --COOH, --C(O)O-alkyl, --C(O)O-alkylenyl-R.sub.4, --C(O)-alkyl, --C(O)-alkylenyl-R.sub.4, --C(O)-halogen, --C(O)NH , --C(O)NH-alkyl, --C(O)NH-alkylenyl-R.sub.4 ; R.sub.7 is a radical selected from the group consisting of O, NH, and S; and R.sub.8 is N, O or S. R.sub.2 and R.sub.3 are each independently selected from the group consisting of alkyl and alkylenyl-R.sub.10, wherein R.sub.10 is selected from the group consisting of --OH, --OTs, halogen, spiperone, spiperone ketal and spiperone-3-yl. Alternatively, R.sub.2 and R.sub.3 together form a heterocyclic ring, optionally substituted with at least one radical selected from the group consisting of alkyl, alkoxy, OH, OTs, halogen, alkylenyl-R.sub.10, carbonyl, spiperone, spiperone ketal and spiperone-3-yl. In the compounds of formula (I), one or more of the hydrogen, halogen or carbon atoms can, optionally, be replaced with a radiolabel.

Crystal structures of 3,5-bis-[(E)-3-hy-droxy-benzyl-idene]-1-methyl-piperidin-4-one and 3,5-bis-[(E)-2-chloro-benzyl-idene]-1-methyl-piperidin-4-one.

PubMed

Eryanti, Yum; Zamri, Adel; Herlina, Tati; Supratman, Unang; Rosli, Mohd Mustaqim; Fun, Hoong-Kun

2015-12-01

The title compounds, C20H19NO3, (1), and C20H17Cl2NO, (2), are the 3-hy-droxy-benzyl-idene and 2-chloro-benzyl-idene derivatives, respectively, of curcumin [systematic name: (1E,6E)-1,7-bis-(4-hy-droxy-3-meth-oxy-phen-yl)-1,6-hepta-diene-3,5-dione]. The dihedral angles between the benzene rings in each compound are 21.07 (6)° for (1) and 13.4 (3)° for (2). In both compounds, the piperidinone rings adopt a sofa confirmation and the methyl group attached to the N atom is in an equatorial position. In the crystal of (1), two pairs of O-H⋯N and O-H⋯O hydrogen bonds link the mol-ecules, forming chains along [10-1]. The chains are linked via C-H⋯O hydrogen bonds, forming undulating sheets parallel to the ac plane. In the crystal of (2), mol-ecules are linked by weak C-H⋯Cl hydrogen bonds, forming chains along the [204] direction. The chains are linked along the a-axis direction by π-π inter-actions [inter-centroid distance = 3.779 (4) Å]. For compound (2), the crystal studied was a non-merohedral twin with the refined ratio of the twin components being 0.116 (6):0.886 (6).

Development of Oseltamivir Phosphonate Congeners as Anti-Influenza Agents

PubMed Central

Cheng, Ting-Jen R.; Weinheimer, Steven; Tarbet, E. Bart; Jan, Jia-Tsrong; Cheng, Yih-Shyun E.; Shie, Jiun-Jie; Chen, Chun-Lin; Chen, Chih-An; Hsieh, Wei-Che; Huang, Pei-Wei; Lin, Wen-Hao; Wang, Shi-Yun; Fang, Jim-Min; Hu, Oliver Yoa-Pu; Wong, Chi-Huey

2012-01-01

Oseltamivir phosphonic acid (tamiphosphor, 3a), its monoethyl ester (3c), guanidino-tamiphosphor (4a) and its monoethyl ester (4c) are potent inhibitors of influenza neuraminidases. They inhibit the replication of influenza viruses, including the oseltamivir-resistant H275Y strain, at low nM to pM levels, and significantly protect mice from infection with lethal doses of influenza viruses when orally administered with 1 mg/kg or higher doses. These compounds are stable in simulated gastric fluid, liver microsomes and human blood, and are largely free from binding to plasma proteins. Pharmacokinetic properties of these inhibitors are thoroughly studied in dogs, rats and mice. The absolute oral bioavailability of these compounds was lower than 12%. No conversion of monoester 4c to phosphonic acid 4a was observed in rats after intravenous administration, but partial conversion of 4c was observed with oral administration. Advanced formulation may be investigated to develop these new anti-influenza agents for better therapeutic use. PMID:23009169

Relative contribution of C3 and C4 type terrestrial organic matter in the Mahanadi offshore (Bay of Bengal) sediments and climatic implication.

NASA Astrophysics Data System (ADS)

da Silva, Rheane; Mazumdar, Aninda; Naik, Bg

2017-04-01

C3 and C4 are dominant vegetation in terrestrial environment. The primary product of photosynthesis of C3 plants is a 3 carbon bearing compound called phosphoglycerate (PGA). In contrast, CO2 is transferred to bundle sheath cells via 4 carbon bearing compound oxaloacetate/mallate and fixed by RuBiSCO in C4 plants. This marked variation in CO2 diffusion across stomata and enzymatic pathways lead to differences in stable carbon isotope ratios. Factors that control relative abundance of these vegetation types are concentration of p-CO2, temperature and humidity. Low p-CO2, air temperature below cross over temperature and aridity are the climatic parameters favoring expansion of C4 type vegetation, whereas higher extreme conditions promote greater C3 type production (Ehleringer, J. R, 2005). In marine sediment n-alkane (lipid fraction) distribution and compound specific isotope ratios are ideal markers to characterize nature of terrestrial organic flux owing to high diagenetic stability and near 100% extraction efficiency. We report here the relative abundance of C3-C4 vegetation over 8 marine isotope stages covering 300kyr. A 39.08 m long core (MD 161-19) was collected onboard ORV Marion Dufresne, at a water depth of 1480 m (Lat: 18 59.1092N Long: 85 41.1669E) (Mazumdar., et. al. 2014) for the study of sediment physico chemical properties and their link to paleoclimatic variation. The carbon isotope ratios of C-27 n-alkane range from -35.3‰ to -23.6‰ VPDB. 13C enrichment trends indicate a greater contribution from C4 vegetation type and 13C depletion trends are attributed to greater flux of C3 type vegetation. Mass balance calculation to reconstruct the temporal variation in C3/ C4 ratios is carried out using the end member values of -34.5‰ and -19.8‰ respectively (Collister.,et. al. 1994). The calculated C3/C4 ratio is 27:73 at LGM and shifts to 71:29 around 6 kyr BP. Based on results, we observe that colder isotope substages characterized by lower pCO2 saw relative expansion of C4 vegetation while warmer, high pCO2 periods supported C3 expansion. A high resolution work is being carried out to get better understanding on actual limiting factors across the last 300 ky responsible for changes in C3 vs C4 expansion. Our data may help in understanding how vegetation may respond to future global warming and climate change including pCO2 build up, change in air temperature and monsoonal rainfall. References: • Collister, James W., et al. "Compound-specific δ 13C analyses of leaf lipids from plants with differing carbon dioxide metabolisms." Organic Geochemistry 21.6-7 (1994): 619-627. • Ehleringer, J. R. The influence of atmospheric CO2, temperature, and water on the abundance of C3/C4 taxa. In A history of atmospheric CO2 and its effects on plants, animals, and ecosystems Springer New York 214-231 (2005). • Mazumdar, A., et al. "Pore-water chemistry of sediment cores off Mahanadi Basin, Bay of Bengal: Possible link to deep seated methane hydrate deposit." Marine and Petroleum Geology 49 (2014): 162-175.

Synthesis, structural characterization and dielectric behavior of new oxime-cyclotriphosphazene derivatives

NASA Astrophysics Data System (ADS)

Koran, Kenan; Özen, Furkan; Biryan, Fatih; Görgülü, Ahmet Orhan

2016-02-01

The cyclotriphosphazene compound (2) bearing formyl groups as side groups was obtained from the reaction of 2,2-Dichloro-4,4,6,6-bis[spiro(2‧,2″-dioxy-1‧,1″-biphenylyl)]cyclotriphosphazene (1) with 4-hydroxy-3-methoxybenzaldehyde in the presence K2CO3 in tetrahydrofuran. Oxime-cyclotriphosphazene compound (3) was synthesized from the reaction of compound 2 with hydroxylamine hydrochloride in pyridine. The synthesized oxime-phosphazene compound (3) was reacted with alkyl and acyl halides. As a results, the cyclotriphosphazene compounds (1-10) bearing oxime ether and ester as side groups were obtained. The chemical structures of these compounds (1-10) were determined by elemental analysis, FT-IR, 1H, 13C and 31P NMR spectroscopic methods. Dielectric constant, dielectric loss factors and conductivity properties of cyclotriphosphazene compounds were measured over the frequency range from 100 Hz to 2 kHz at 25 °C and compared with each other. It is found that ester substituted cyclotriphosphazenes have higher dielectric constant. Our study suggests that these phosphazenes promising candidate materials in multifunctional optoelectronic devices.

Spectroscopic, electrochemical DNA binding and in vivo anti-inflammatory studies on newly synthesized Schiff bases of 4-aminophenazone.

PubMed

Arshad, Nasima; Ahmad, Mukhtar; Ashraf, Muhammad Zaman; Nadeem, Humaira

2014-09-05

4-Aminophenazone (Ap-1) Schiff bases i.e., 4-{(3,4,5-trimethoxybenzylidine) amino}phenazone (Ap-2), 4-{(2-chlorobenzylidine) amino}phenazone (Ap-3) and 4-{(4-chlorobenzylidine)amino} phenazone (Ap-4) were synthesized and characterized by different spectroscopic techniques. Interaction of these compounds with ds.DNA was investigated through UV-Visible spectroscopy, fluorescence spectroscopy and cyclic voltammetry at stomach (4.7) and blood (7.4) pH under 37 °C (human body temperature). Instrumental findings were further quantified both kinetically and thermodynamically. Results obtained through these techniques inferred intercalative mode of binding of all the compounds with DNA. The binding constant data, "Kb", and free energy change, ΔG, indicated comparatively greater binding affinity and more spontaneity of binding of compounds with DNA at stomach pH (4.7), respectively. However, among these compounds, Ap-4 showed comparatively greater binding at both the pH. Formation of compound-DNA complex was further confirmed through the decrease in diffusion rates after the addition of DNA. The in vivo anti-inflammatory activity of the compounds was evaluated using the carrageenan-induced hind paw edema method. The results revealed that among all the compounds, Ap-4 showed greater percentage of edema inhibition compared to standard drug. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparison crystal structure conformations of two structurally related biphenyl analogues: 4,4′-bis­[3-(pyrrolidin-1-yl)prop-1-yn-1-yl]-1,1′-biphenyl and 4,4′-bis­{3-[(S)-2-methyl­pyrrolidin-1-yl]prop-1-yn-1-yl}-1,1′-biphen­yl

PubMed Central

Wan, Anqi; Penthala, Narsimha Reddy; Fifer, E. Kim; Parkin, Sean; Crooks, Peter A.

2015-01-01

The title compounds, C26H28N2, (I), and C28H32N2, (II), were designed based on the structure of the potent α9α10 nicotinic acetyl­choline receptor antagonist ZZ161C {1,1′-[[1,1′-biphen­yl]-4,4′-diylbis(prop-2-yne-3,1-di­yl)]bis­(3,4-di­methyl­pyridin-1-ium) bromide}. In order to improve the druglikeness properties of ZZ161C for potential oral administration, the title compounds (I) and (II) were prepared by coupling 4,4′-bis­(3-bromo­prop-1-yn-1-yl)-1,1′-biphenyl with pyrrol­idine, (I), and (S)-2-methyl­pyrrolidine, (II), respectively, in aceto­nitrile at room temperature. The asymmetric unit of (I) contains two half mol­ecules that each sit on sites of crystallographic inversion. As a result, the biphenyl ring systems in compound (I) are coplanar. The biphenyl ring system in compound (II), however, has a dihedral angle of 28.76 (11)°. In (I), the two independent mol­ecules differ in the orientation of the pyrrolidine ring (the nitro­gen lone pair points towards the biphenyl rings in one mol­ecule, but away from the rings in the other). The torsion angles about the ethynyl groups between the planes of the phenyl rings and the pyrrolidine ring N atoms are 84.15 (10) and −152.89 (10)°. In compound (II), the corresponding torsion angles are 122.0 (3) and 167.0 (3)°, with the nitro­gen lone pairs at both ends of the mol­ecule directed away from the central biphenyl rings. PMID:26594393

Crystal structure of 2-[chloro-(4-meth-oxy-phen-yl)meth-yl]-2-(4-meth-oxy-phen-yl)-5,5-di-methyl-cyclo-hexane-1,3-dione.

PubMed

Chelli, Saloua; Troshin, Konstantin; Lakhdar, Sami; Mayr, Herbert; Mayer, Peter

2016-03-01

In the title compound, C23H25ClO4, the cyclo-hexane ring adopts a chair conformation with the 4-meth-oxy-phenyl substituent in an axial position and the chloro-(4-meth-oxy-phen-yl)methyl substituent in an equatorial position. The packing features inversion dimers formed by pairs of C-H⋯O contacts and strands along [100] and [010] established by further C-H⋯O and C-H⋯Cl contacts, respectively.

Total Syntheses of (±)-Ovalicin, C4(S*)-Isomer, and Its C5-Analogs and Anti-trypanosomal Activities∥

PubMed Central

Hua, Duy H.; Zhao, Huiping; Battina, Srinivas K.; Lou, Kaiyan; Jimenez, Ana L.; Desper, John; Perchellet, Elisabeth M.; Perchellet, Jean-Pierre H.; Chiang, Peter K.

2008-01-01

Total syntheses of (±)-ovalicin, its C4(S*)-isomer 44, and C5-side chain intermediate 46 were accomplished via an intramolecular Heck reaction of (Z)-3-(t-butyldimethylsilyloxy)-1-iodo-1,6-heptadiene and a catalytic amount of palladium acetate. Subsequent epoxidation, dihydroxylation, methylation and oxidation led to (3S*,5R*,6R*)-5-methoxy-6-(t-butyldimethylsilyloxy)-1-oxaspiro[2.5]octan-4-one (2), a reported intermediate. The addition of a side chain with cis-1-lithio-1,5-dimethyl-1,4-hexadiene (27) followed by oxidation afforded (±)-ovalicin. The functional group manipulation afforded a number of regio- and stereoisomers, which allow the synthesis of analogs for bioevaluation. The structure of 44 was firmly established via a single-crystal X-ray analysis. The stereochemistry at C4 generated from the addition reactions of alkenyllithium with ketones 2, 40, and 45 is dictated by C6-alkoxy functionality. Anti-trypanosomal activities of various ovalicin analogs and synthetic intermediates were evaluated, and C5-side chain analog, 46, shows the strongest activity. Compound 44 shows antiproliferative effect against HL-60 tumor cells in vitro. Compounds 46 and a precursor, (3S*,4R*,5R*,6R*)-5-methoxy-4-[(E)-1’,5’-dimethylhexa-1’,4’–dienyl)]-6-(t-butyldimethylsilyloxy)-1-oxaspiro[2.5]octan-4-ol (28), may be explored for the development of anti-parasitic drugs. PMID:18356059

Synthesis of new 2-substituted pyrido[2,3-d]pyrimidin-4(1H)-ones and their antibacterial activity.

PubMed

Lakshmi Narayana, B; Ram Rao, A Raghu; Shanthan Rao, P

2009-03-01

2-Substituted-5,7-dimethyl pyrido[2,3-d]pyrimidin-4(1H)-ones (8) were synthesized by oxidation of 2-substituted-5,7-dimethyl dihydropyrido[2,3-d]pyrimidin-4(1H)-ones (7) which were in turn prepared from 2-amino-4,6-dimethyl nicotinamide (5) and substituted aryl aldehydes (6). 2-Amino-4,6-dimethyl nicotinamide (5) was prepared from ethyl cyanoacetate (1) via malonamamidine hydrochloride (3). The compounds were characterized by IR, NMR, MS and elemental analyses. Compounds 7 and 8 were screened for antibacterial activity against gram positive and gram negative bacteria. Dehydrogenated compounds (8) showed less antibacterial activity than the compounds 7. Among all the test compounds screened for antibacterial activity 7c (1.25 microg/ml) showed greater activity. All the synthesized compounds were found inactive when screened for antifungal activity at the concentration of 200 microg/ml.

Palladium-Catalyzed Formal Cross-Coupling of Diaryl Ethers with Amines: Slicing the 4-O-5 Linkage in Lignin Models.

PubMed

Zeng, Huiying; Cao, Dawei; Qiu, Zihang; Li, Chao-Jun

2018-03-26

Lignin is the second most abundant organic matter on Earth, and is an underutilized renewable source for valuable aromatic chemicals. For future sustainable production of aromatic compounds, it is highly desirable to convert lignin into value-added platform chemicals instead of using fossil-based resources. Lignins are aromatic polymers linked by three types of ether bonds (α-O-4, β-O-4, and 4-O-5 linkages) and other C-C bonds. Among the ether bonds, the bond dissociation energy of the 4-O-5 linkage is the highest and the most challenging to cleave. To date, 4-O-5 ether linkage model compounds have been cleaved to obtain phenol, cyclohexane, cyclohexanone, and cyclohexanol. The first example of direct formal cross-coupling of diaryl ether 4-O-5 linkage models with amines is reported, in which dual C(Ar)-O bond cleavages form valuable nitrogen-containing derivatives. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

An Investigation of Facile One-Pot Synthesis of Li2FeSiO4/C Composite for Li Ion Batteries

NASA Astrophysics Data System (ADS)

Thirumoolam, Mani Chandran; Manikandan, Ananda Kumar; Sivaramakrishnan, Balaji; Kaluvan, Hariharan; Gowravaram, Mohan Rao

2018-03-01

Li2FeSiO4 and its carbon composite are prepared by an urea-assisted combustion method. The synthesis has been carried out in different urea concentrations, namely 1 Molar (M), 2 M and 3 M urea in the cost-effective ambient atmospheric condition. The x-ray diffraction analysis confirms the orthorhombic structure of Li2FeSiO4 compounds. The urea-assisted combustion reaction enhanced the phase purity of the compound and prevented the oxidation of ferrous ions in Li2FeSiO4. The x-ray photo electron spectroscopy analysis further confirmed the reduction of Fe3+ concentration in Li2FeSiO4 while adding urea. The Li2FeSiO4 compound formation in the presence of urea occurred at a temperature < 623 K. The one-pot synthesis of Li2FeSiO4/C with the help of starch and urea in ambient atmospheric condition resulted in Li2FeSiO4 with an orthorhombic crystal structure. The carbon coating in an amorphous nature is observed and the lattice dimension values of Li2FeSiO4/C are 6.248 Å, 5.330 Å, and 5.029 Å. The lattice parameter has remained unchanged with carbon addition. The addition of 5% carbon to Li2FeSiO4 improves the electrical conductivity and lithium diffusion coefficient to 7.24 × 10-4 S cm-1 and 5.54 × 10-6 cm2, respectively. The coulombic efficiency and capacity retention after 50 cycles of Li2FeSiO4/C composite are around 83% and 95%, respectively.

Molecular and polymeric uranyl and thorium hybrid materials featuring methyl substituted pyrazole dicarboxylates and heterocyclic 1,3-diketones

NASA Astrophysics Data System (ADS)

Carter, Korey P.; Kerr, Andrew T.; Taydakov, Ilya V.; Cahill, Christopher L.

2018-02-01

A series of seven novel f-element bearing hybrid materials have been prepared from either methyl substituted 3,4 and 4,5-pyrazoledicarboxylic acids, or heterocyclic 1,3- diketonate ligands using hydrothermal conditions. Compounds 1, [UO2(C6H4N2O4)2(H2O)], and 3, [Th(C6H4N2O4)4(H2O)5]·H2O feature 1-Methyl-1H-pyrazole-3,4-dicarboxylate ligands (SVI-COOH 3,4), whereas 2, [UO2(C6H4N2O4)2(H2O)], and 4, [Th(C6H5N2O4)(OH)(H2O)6]2·2(C6H5N2O4)·3H2O feature 1-Methyl-1H-pyrazole-4,5-dicarboxylate moieties (SVI-COOH 4,5). Compounds 5, [UO2(C13H15N4O2)2(H2O)]·2H2O and 6, [UO2(C11H11N4O2)2(H2O)]·4.5H2O feature 1,3-bis(4-N1-methyl-pyrazolyl)propane-1,3-dione and 1,3-bis(4-N1,3-dimethyl-pyrazolyl)propane-1,3-dione respectively, whereas the heterometallic 7, [UO2(C11H11N4O2)2(CuCl2)(H2O)]·2H2O is formed by using 6 as a metalloligand starting material. Single crystal X-ray diffraction indicates that all coordination to either [UO2]2+ or Th(IV) metal centers is through O-donation as anticipated. Room temperature, solid-state luminescence studies indicate characteristic uranyl emissive behavior for 1 and 2, whereas those for 5 and 6 are weak and poorly resolved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuz'mina, L. G., E-mail: kuzmina@igic.ras.ru; Gunina, M. A.; Churakov, A. V.

Two aromatic esters with the formulas C{sub 6}H{sub 13}-O-C{sub 6}H{sub 4}-C(O)O-C{sub 6}H{sub 4}-O-C{sub 7}H{sub 15} (1) and C{sub 7}H{sub 15}-O-C{sub 6}H{sub 4}-C(O)O-C{sub 6}H{sub 4}-O-C{sub 4}H{sub 9} (2) belonging to nematic liquid-crystal compounds were studied by X-ray diffraction. Compound 1 crystallizes in two modifications: monoclinic (1-m) and triclinic (1-tr). The crystal packing of 1 and 2 is built from alternating loosely packed aliphatic regions and closely packed aromatic regions. In crystal structures 1-m and 2, the aromatic regions are linked into chains by hydrogen bonds with the participation of the carbonyl oxygen atom of the ester group and the C-H fragmentmore » of the benzene ring, but these hydrogen bonds in 1-m are much weaker than in 2. In 1-m there are {pi}-stacking interactions between the molecules, resulting in the formation of centrosymmetric dimers with an interplanar distance of 3.45 A. In 1-tr, the aromatic fragments form a herringbone packing motif favorable for a two-dimensional network of directional C-H...{pi}-system interactions.« less

Synthesis and antimicrobial evaluation of L-phenylalanine-derived C5-substituted rhodanine and chalcone derivatives containing thiobarbituric acid or 2-thioxo-4-thiazolidinone.

PubMed

Jin, Xin; Zheng, Chang-Ji; Song, Ming-Xia; Wu, Yan; Sun, Liang-Peng; Li, Yin-Jing; Yu, Li-Jun; Piao, Hu-Ri

2012-10-01

Four novel series of compounds, including the l-phenylalanine-derived C5-substituted rhodanine (6a-q, 7a-j) and chalcone derivatives containing thiobarbituric acid or 2-thioxo-4-thiazolidinone (9a-e, 11a-e) have been designed, synthesized, characterized, and evaluated for their antibacterial activity. Some of these compounds showed significant antibacterial activity against Gram-positive bacterias, especially against the strains of multidrug-resistant clinical isolates, among which compounds 6c-e, 6g, 6i, 6j and 6q exhibiting high levels of antimicrobial activity against Staphylococcus aureus RN4220 with minimum inhibitory concentration (MIC) values of 2 μg/mL. Compound 6q showed the most potent activity of all of the compounds against all of the test multidrug-resistant clinical isolates tested. Unfortunately, however, none of the compounds were active against Gram-negative bacteria at 64 μg/mL. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Unusual open chain quinolinyl peroxol and its alcohol counterpart obtained through a modified Skraup-Doebner-Von Miller quinoline synthesis: theoretical studies and complete (1) H- and (13) C-NMR assignments.

PubMed

Fotie, Jean; Kemami Wangun, Hilaire V; Dreux, Katelyn; Sommerfeld, Thomas; Pittman, Jacob

2012-01-01

Because of their extreme instability, it is generally difficult to synthesize and fully characterize open chain peroxides, also known as peroxols. In our attempt to investigate the mechanism of the Skraup-Doebner-Von Miller quinoline synthesis, we were able to obtain an unusual open chain peroxy-quinoline, namely, 4-(8-ethoxy-2,3-dihydro-1H-cyclopenta[c]quinolin-4-yl)butane-1-peroxol (1), and its alcohol counterpart, namely 4-(8-ethoxy-2,3-dihydro-1H-cyclopenta[c]quinolin-4-yl)butan-1-ol (2) obtained as a side product during the same reaction. Although structurally similar, these two compounds appeared to display some very distinct physical and spectroscopic characteristics. This work reports detailed NMR studies and full (1) H and (13)  C NMR assignments for these two compounds. These assignments are based upon the analysis of the NMR spectra of these compounds including (1) H, (13)  C, COSY, gHSQC and gHMBC. The effect of the peroxide functional group on the chemical shift of neighboring carbons and protons was also investigated by comparing the NMR data of these two compounds. Furthermore, the effects of potential hydrogen bondings in 1, 2, and possible 1-1 dimer, 2-2 dimer and in prototypical model systems, as well as the stability of these compounds, were investigated computationally. The computed dissociation energies and NMR data support the interpretation of the experimental data. Copyright © 2012 John Wiley & Sons, Ltd.

The effect of Li2CO3 substitution on synthesis of LiBOB compounds as salt of electrolyte battery lithium ion

NASA Astrophysics Data System (ADS)

Lestariningsih, Titik; Wigayati, Etty Marty; Sabrina, Qolby; Prihandoko, Bambang; Priyono, Slamet

2018-04-01

Development of the synthesis of LiB(C2O4)2 compounds continues to evolve along with the need for electrolyte salts to support the research of the manufacture of lithium ion batteries. A study had been conducted on the effect of Li2CO3 substitution on the synthesis of LiB(C2O4)2 or LiBOB compounds. LiBOB was a major candidate to replace LiPF6 as a highly toxic lithium battery electrolyte and harmful to human health. Synthesis of Lithium bis(oxalato) borate used powder metallurgy method. The raw materials used are H2C2O4.2H2O, Li2CO3 or LiOH and H2BO3 from Merck Germany products. The materials are mixed with 2: 1: 1 mol ratio until homogeneous. The synthesis of LiBOB refers to previous research, where the heating process was done gradually. The first stage heating is carried out at 120°C for 4 hours, then the next stage heating is carried out at 240°C for 7 hours. The sample variation in this study was to distinguish the lithium source from Li2CO3 and LiOH. Characterization was done by XRD to know the phase formed, FTIR to confirm that functional group of LiB(C2O4)2 compound, SEM to know the morphological structure, and TG/DTA to know the thermal properties. The results of the analysis shows that LiBOB synthesis using Lithium source from Li2CO3 has succeeded to form LiBOB compound with more LiBOB phase composition is 59.1% and 40.9% LiBOB hydrate phase, SEM morphology shows powder consist of elongated round particle porous and similar to LiBOB commercial and show higher thermal stability.

Pharmacoinformatics exploration of polyphenol oxidases leading to novel inhibitors by virtual screening and molecular dynamic simulation study.

PubMed

Hassan, Mubashir; Abbas, Qamar; Ashraf, Zaman; Moustafa, Ahmed A; Seo, Sung-Yum

2017-06-01

Polyphenol oxidases (PPOs)/tyrosinases are metal-dependent enzymes and known as important targets for melanogenesis. Although considerable attempts have been conducted to control the melanin-associated diseases by using various inhibitors. However, the exploration of the best anti-melanin inhibitor without side effect still remains a challenge in drug discovery. In present study, protein structure prediction, ligand-based pharmacophore modeling, virtual screening, molecular docking and dynamic simulation study were used to screen the strong novel inhibitor to cure melanogenesis. The 3D structures of PPO1 and PPO2 were built through homology modeling, while the 3D crystal structures of PPO3 and PPO4 were retrieved from PDB. Pharmacophore modeling was performed using LigandScout 3.1 software and top five models were selected to screen the libraries (2601 of Aurora and 727, 842 of ZINC). Top 10 hit compounds (C1-10) were short-listed having strong binding affinities for PPO1-4. Drug and synthetic accessibility (SA) scores along with absorption, distribution, metabolism, excretion and toxicity (ADMET) assessment were employed to scrutinize the best lead hit. C4 (name) hit showed the best predicted SA score (5.75), ADMET properties and drug-likeness behavior among the short-listed compounds. Furthermore, docking simulations were performed to check the binding affinity of C1-C10 compounds against target proteins (PPOs). The binding affinity values of complex between C4 and PPOs were higher than those of other complexes (-11.70, -12.1, -9.90 and -11.20kcal/mol with PPO1, PPO2, PPO3, or PPO4, respectively). From comparative docking energy and binding analyses, PPO2 may be considered as better target for melanogenesis than others. The potential binding modes of C4, C8 and C10 against PPO2 were explored using molecular dynamics simulations. The root mean square deviation and fluctuation (RMSD/RMSF) graphs results depict the significance of C4 over the other compounds. Overall, bioactivity and ligand efficiency profiles suggested that the proposed hit may be more effective inhibitors for melanogenesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buragohain, Amlan; Couck, Sarah; Van Der Voort, Pascal

Four existing and three new functionalized chromium terephthalates having MIL-101 topology and denoted as Cr-MIL-101-X (existing ones with X=–F, 1-F; –Cl, 2-Cl; –Br, 3-Br; –CH{sub 3}, 4-CH{sub 3}; new ones with X=–C{sub 6}H{sub 4}, 5-C{sub 6}H{sub 4}; –F{sub 2}, 6-F{sub 2}, –(CH{sub 3}){sub 2}, 7-(CH{sub 3}){sub 2}) were synthesized under hydrothermal conditions. All the materials except 5-C{sub 6}H{sub 4} could be prepared by a general synthetic route, in which the mixtures of CrO{sub 3}, H{sub 2}BDC-X (BDC=1,4-benzenedicarboxylate) linkers, conc. HCl and water with a molar ratio of 1:1:3.9:222.2 were reacted at 180 °C for 144 h. Compared to the 144more » h of synthesis time, three of the compounds, namely 1-Cl, 2-Br and 5-C{sub 6}H{sub 4}, could be prepared in much shorter reaction times (12–18 h at 180–210 °C). The materials possess high thermal stability up to 270–300 °C in an air atmosphere. The activated compounds exhibit significant porosity (S{sub BET} range: 1273–2135 m{sup 2} g{sup −1}). At 0 °C and 1 bar, the CO{sub 2} adsorption capacities of the compounds fall in the 1.7–2.9 mmol g{sup −1} range. Compounds 1-F and 6-F{sub 2} showed enhanced CO{sub 2} uptake values compared to parent Cr-MIL-101. The benzene adsorption capacities of the compounds lie in the range of 66.2–139.5 molecules per unit cell at 50 °C and p/p{sub 0}=0.35. The increased benzene uptake value of 1-F compared to un-functionalized Cr-MIL-101 and 4-CH{sub 3} suggests that the fluorination has induced more hydrophobicity in Cr-MIL-101 as compared to the methylation. - Graphical abstract: Benzene adsorption by seven functionalized Cr-MIL-101-X metal-organic framework (MOF) materials Display Omitted - Highlights: • Seven functionalized Cr-MIL-101-X materials were synthesized solvothermally. • All Cr-MIL-101-X materials exhibited high thermal stability up to 270–300 °C in air. • All Cr-MIL-101-X compounds displayed considerable porosity towards N{sub 2}, CO{sub 2} and benzene. • Mono- and di-fluorinated Cr-MIL-101 materials showed enhanced CO{sub 2} adsorption capacities. • Cr-MIL-101-F adsorbed more benzene than non- and methyl-functionalized Cr-MIL-101.« less

Synthesis, crystal structures and luminescence properties of new multi-component co-crystals of isostructural Co(II) and Zn(II) complexes

NASA Astrophysics Data System (ADS)

Tella, Adedibu C.; Owalude, Samson O.; Omotoso, Mary F.; Olatunji, Sunday J.; Ogunlaja, Adeniyi S.; Alimi, Lukman O.; Popoola, Olugbenga K.; Bourne, Susan A.

2018-04-01

Two novel isostructural compounds containing multi-component co-crystals [M(C6H4NO2)2(H2O)2](C9H6O6)2 (M = Co (1), Zn (2), C6H4NO2 = Picolinic acid, C9H6O6 = Trimesic acid) have been synthesized. The compounds were characterized by elemental analysis, FT-IR, UV-Visible and 1H NMR spectroscopies as well as thermal and single crystal X-ray diffraction analyses. Single crystal X-ray diffraction analysis reveals that 1 and 2 are isostructural. Compound 1 crystallizes in triclinic space group (P-1, with a = 5.154 (10) Å, b = 11.125 (2) Å, c = 14.113 (3) Å, α = 91.01 (3)°, β = 100.54 (3)°, and γ = 102.71 (3)°). In a similar fashion, compound 2 crystallizes in triclinic space group (P-1, with a = 5.1735 (3) Å, b = 11.0930 (10) Å, c = 14.1554 (8) Å, α = 91.70 (3)°, β = 100.26 (3)°, γ = 102.90 (3)°). The metal (II) cation presents distorted MN2O4 octahedral geometry with H2O molecules coordinated to the metal in equatorial position while the picolinic acid molecules are axially coordinated through the pyridine N atom. The two trimesic acid molecules are not part of the first coordination sphere. Compounds 1 and 2 constitute an example of a class of coordination compound of multicomponent crystals having trimesic acid outside the coordination sphere where it is neither protonated or deprotonated. The two compounds were investigated for luminiscence properties.

Emissions of Tetrafluoromethane (CF4) and Hexafluoroethane (C2F6) from East Asian Aluminum and Semiconductor Industries

NASA Astrophysics Data System (ADS)

Kim, J.; Li, S.; Muhle, J.; Fang, X.; Manning, A. J.; Arnold, T.; Park, S.; Park, M.; Saito, T.; Yokouchi, Y.; Stohl, A.; Weiss, R. F.; Kim, K.

2013-12-01

Tetrafluoromethane (CF4) and Hexafluoroethane (C2F6) are among the most potent greenhouse gases (GHGs), with atmospheric lifetimes of 50,000 and 10,000 years and 100-year Global Warming Potentials of 7,490 and 12,200, respectively. The Chinese aluminum smelting (AL) industry, accounting for 39% of the global aluminum production in 2010, has become a significant emitter of these compounds to the atmosphere, . The AL industry has estimated its Chinese emissions averaged over 2008-2010 at 1.4 Gg/yr of CF4 and 0.06 Gg/yr of C2F6. In this study we combine East Asian measurements of C2F6 at Gosan (Jeju Island, Korea), Hateruma, and Ochi-Ishi (Japan) and of CF4 at Gosan, using inversion techniques and two Lagrangian particle dispersion models (FLEXPART and NAME), to estimate the emissions of these two compounds from China and East Asia. Our results yield total emissions from China for the 2008-2010 period of approximately 4 × 0.5 Gg/yr for CF4 and 0.8 × 0.1 Gg/yr for C2F6. These results may be reconciled if emissions of these compounds from China's semiconductor (SC) industry are larger than currently estimated. However, evidence presented in the analysis of the inversion results and in the C2F6/CF4 emission ratios observed for China suggest that China's AL industry emissions are likely to be the dominant source of the discrepancy between reported emissions and those inferred from atmospheric measurements. As the AL and SC industries evolve toward new manufacturing technologies that reduce GHG emissions, continued and improved atmospheric measurements and modeling in this region will be useful in assessing the effectiveness of these changes.

Synthesis, antiproliferative and apoptotic activities of N-(6(4)-indazolyl)-benzenesulfonamide derivatives as potential anticancer agents.

PubMed

Abbassi, Najat; Chicha, Hakima; Rakib, El Mostapha; Hannioui, Abdellah; Alaoui, Mdaghri; Hajjaji, Abdelouahed; Geffken, Detlef; Aiello, Cinzia; Gangemi, Rosaria; Rosano, Camillo; Viale, Maurizio

2012-11-01

Recently, it has been reported that compounds bearing a sulfonamide moiety possess many types of biological activities, including anticancer activity. The present work reports the synthesis and antiproliferative evaluation of some N-(6(4)-indazolyl)benzenesulfonamides and 7-ethoxy-N-(6(4)-indazolyl)benzenesulfonamides. All compounds were evaluated for their in vitro antiproliferative activity against three tumor cell lines: A2780 (human ovarian carcinoma) A549 (human lung adenocarcinoma) and P388 (murine leukemia). The results indicated that sulfonamides 2c, 3c, 6d, 8, 13, 3b and 16 were endowed with a pharmacologically interesting antiproliferative activity with compounds 2c and 3c showing the lower IC(50) (from 0.50 ± 0.09 to 1.83 ± 0.52 μM and from 0.58 ± 0.17 to 5.83 ± 1.83 μM, respectively). Moreover, these indazoles were able to trigger apoptosis through the upregulation of the typical apoptosis markers p53 and bax. As regard to the hypothetic targets of these compounds, a preliminary docking analysis showed that all compounds seemed to interact with β-tubulin, in particular compound 3b that showed the lower Ki. The cytofluorimetric analysis of the cell cycle phases indicates that all compounds, when administered at their IC(75), caused a block in the G2/M phase of the cell cycle with the generation of subpopulations of cells with a number of chromosome >4n. When the IC(50)s were applied we observed a prevalent block in the G0/G1 phase except for compounds 16 and 8 where a partial G2/M block was present with a concomitant decrease of cells in the G0/G1 and S phases of the cell cycle. Altogether these results suggest a possible, but not exclusive, interaction with microtubules. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Synthesis, crystal structure, and thermal behavior of the rare earth sulfates (H{sub 5}O{sub 2})M(SO{sub 4}){sub 2} (M = Ho, Er, Y)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wickleder, M.S.

1998-10-01

The compounds (H{sub 5}O{sub 2})M(SO{sub 4}){sub 2} (M = Ho, Er, Y) were obtained from the metal oxides M{sub 2}O{sub 3} (M = Ho, Er,m Y) using diluted sulfuric acid (80%). The crystal structure of the isotypic compounds has been determined from single-crystal data by direct and Fourier methods. The characteristic feature of the crystal structure is a network of edge-sharing [MO{sub 8}] trigon dodecahedra and [SO{sub 4}] tetrahedra providing channels along [111] which are occupied by disordered H{sub 5}O{sub 2}{sup +} ions. In situ X-ray powder investigations exhibit that the compounds are also formed as intermediate phases during themore » reaction of the hydrogen sulfates M(HSO{sub 4}){sub 3} (M = Ho, Er, Y) with water. According to DSC measurements and temperature-dependent powder diffraction studies, the thermal decomposition of the title compounds follows a two-step mechanism. Around 150 C, two molecules of water are driven off, yielding M(HSO{sub 4})(SO{sub 4}) (M = Ho, Er, Y), and finally, at 320 C, H{sub 2}SO{sub 4} (H{sub 2}O + SO{sub 3}) is released to give the anhydrous sulfates M{sub 2}(SO{sub 4}){sub 3}.« less

Highly active, low-valence molybdenum- and tungsten-amide catalysts for bifunctional imine-hydrogenation reactions.

PubMed

Chakraborty, Subrata; Blacque, Olivier; Fox, Thomas; Berke, Heinz

2014-01-01

The reactions of [M(NO)(CO)4(ClAlCl3)] (M=Mo, W) with (iPr2PCH2CH2)2NH, (PN(H)P) at 90 °C afforded [M(NO)(CO)(PN(H)P)Cl] complexes (M=Mo, 1a; W, 1b). The treatment of compound 1a with KOtBu as a base at room temperature yielded the alkoxide complex [Mo(NO)(CO)(PN(H)P)(OtBu)] (2a). In contrast, with the amide base Na[N(SiMe3 )2 ], the PN(H) P ligand moieties in compounds 1a and 1b could be deprotonated at room temperature, thereby inducing dehydrochlorination into amido complexes [M(NO)(CO)(PNP)] (M=Mo, 3a; W, 3b; PNP=(iPr2PCH2CH2)2N)). Compounds 3a and 3b have pseudo-trigonal-bipyramidal geometries, in which the amido nitrogen atom is in the equatorial plane. At room temperature, compounds 3a and 3b were capable of adding dihydrogen, with heterolytic splitting, thereby forming pairs of isomeric amine-hydride complexes [Mo(NO)(CO)H(PN(H)P)] (4a(cis) and 4a(trans)) and [W(NO)(CO)H(PN(H)P)] (4b(cis) and 4b(trans); cis and trans correspond to the position of the H and NO groups). H2 approaches the Mo/W=N bond in compounds 3a,b from either the CO-ligand side or from the NO-ligand side. Compounds 4a(cis) and 4a(trans) were only found to be stable under a H2 atmosphere and could not be isolated. At 140 °C and 60 bar H2 , compounds 3a and 3b catalyzed the hydrogenation of imines, thereby showing maximum turnover frequencies (TOFs) of 2912 and 1120 h(-1), respectively, for the hydrogenation of N-(4-methoxybenzylidene)aniline. A Hammett plot for various para-substituted imines revealed linear correlations with a negative slope of -3.69 for para substitution on the benzylidene side and a positive slope of 0.68 for para substitution on the aniline side. Kinetics analysis revealed the initial rate of the hydrogenation reactions to be first order in c(cat.) and zeroth order in c(imine). Deuterium kinetic isotope effect (DKIE) experiments furnished a low kH /kD value (1.28), which supported a Noyori-type metal-ligand bifunctional mechanism with H2 addition as the rate-limiting step. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Crystal structure of methyl (4R)-4-(4-meth-oxy-benzo-yl)-4-{[(1R)-1-phenyl-eth-yl]carbamo-yl}butano-ate.

PubMed

Manchado, Alejandro; Salgado, Mateo M; Vicente, Álvaro; Díez, David; Sanz, Francisca; Garrido, Narciso M

2017-04-01

The title compound, C 22 H 25 NO 5 , was prepared by CAN [cerium(IV) ammonium nitrate] oxidation of the corresponding β-lactam. The dihedral angle between the benzene rings is 13.3 (4)° and the C-N-C(=O)-C torsion angle is 176.1 (6)°. In the crystal, amide- C (4) N-H⋯O and reinforcing C-H⋯O hydrogen bonds link the mol-ecules into infinite [010] chains. Further C-H⋯O hydrogen bonds cross-link the chains in the c -axis direction.

Compound C Stimulates Heme Oxygenase-1 Gene Expression via the Nrf2-ARE Pathway to Preserve Human Endothelial Cell Survival

PubMed Central

Liu, Xiao-ming; Peyton, Kelly J.; Shebib, Ahmad R.; Wang, Hong; Durante, William

2011-01-01

We recently identified adenosine monophosphate-activated protein kinase (AMPK) as a novel inducer of heme oxygenase-1 (HO-1) and surprisingly found that compound C (6-[4-(2-piperidin-1-yl-ethoxy)-phenyl]3-pyridin-4-yl-pyrazolo[1,5-a] pyrimidine), a cell-permeable inhibitor of AMPK, could also elevate HO-1 suggesting other AMPK-independent actions for this agent. In this study, we investigated the biochemical mechanism by which compound C stimulates HO-1 expression in human endothelial cells (ECs) and determined the biological significance of the induction of HO-1 by compound C in these cells. Compound C stimulated a concentration- and time-dependent increase in HO-1 expression and an increase in HO-1 promoter activity that was abrogated by mutating the antioxidant responsive elements (AREs) in the HO-1 promoter or by overexpressing a dominant negative mutant of NF-E2-related factor-2 (Nrf2). Compound C also stimulated Nrf2 expression and this was associated with an increase in the production of reactive oxygen species and with a decline in intracellular glutathione levels. Interestingly, the glutathione donor N-acetyl-L-cysteine or the NADPH oxidase inhibitor apocynin blocked the induction of HO-1 by compound C. Finally, compound C stimulated EC death and this was potentiated by silencing HO-1 expression and reversed by the administration of CO, biliverdin, or bilirubin. In conclusion, this study demonstrates that compound C stimulates HO-1 gene expression in human vascular endothelium via the activation of the Nrf2/ARE signaling pathway to counteract compound C-mediated cell death. The ability of compound C to induce HO-1 expression may contribute to the pleiotropic actions of this agent and suggest caution when using compound C to probe for AMPK functions. PMID:21635873

Anti-inflammatory and chemopreventive effects of triterpene cinnamates and acetates from shea fat.

PubMed

Akihisa, Toshihiro; Kojima, Nobuo; Kikuchi, Takashi; Yasukawa, Ken; Tokuda, Harukuni; T Masters, Eliot; Manosroi, Aranya; Manosroi, Jiradej

2010-01-01

Four triterpene acetates, alpha-amyrin acetate (1a), beta-amyrin acetate (2a), lupeol acetate (3a), and butyrospermol acetate (4a), and four triterpene cinnamates, alpha-amyrin cinnamate (1c), beta-amyrin cinnamate (2c), lupeol cinnamate (3c), and butyrospermol cinnamate (4c), were isolated from the kernel fat (n-hexane extract) of the shea tree (Vitellaria paradoxa; Sapotaceae). Upon evaluation of these eight triterpene esters for inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation (1 microg/ear) in mice, all of the compounds tested exhibited marked anti-inflammatory activity, with ID50 values in the range of 0.15-0.75 micromol/ear, and among which compound 3c showed the highest activity with ID(50) of 0.15 micromol/ear. Compound 3c (10 mg/kg) further exhibited anti-inflammatory activity on rat hind paw edema induced by carrageenan, with the percentage of inflammation at 1, 3, and 5 h of 35.4, 41.5, and 45.5%, respectively. The eight triterpene esters were then evaluated for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) in Raji cells as a primary screening test for inhibitors of tumor promoters. All the compounds showed moderate inhibitory effects. Furthermore, compound 3c exhibited inhibitory effect on skin tumor promotion in an in vivo two-stage carcinogenesis test using 7,12-dimethylbenz [a] anthracene (DMBA) as an initiator and TPA as a promoter. The biological activities of triterpene acetate and cinnamate esters, together with the exceptionally high levels of these triterpenes in shea fat, indicate that shea nuts and shea fat (shea butter) constitute a significant source of anti-inflammatory and anti-tumor promoting compounds.

Synthesis and characterization of the heavy-fermion compound CePtAl 4Ge 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shin, Soohyeon; Rosa, Priscila Ferrari Silveira; Ronning, Filip

Here, we report the synthesis of the Ce-based quaternary compound CePtAl 4Ge 2 that crystallizes in the trigonal structure (space group R 3¯m, 166) with unit cell parameters, a = 4.1995(5) Å, c = 31.851(7) Å, and γ = 120°. Powder X-ray diffraction and energy dispersive X-ray spectroscopy show that CePtAl 4Ge 2 (LaPtAl 4Ge 2) is in a single, homogeneous phase. Magnetic susceptibility, electrical resistivity, and heat capacity measurements of CePtAl 4Ge 2 show that it exhibits antiferromagnetic behavior below 2.3 K. The magnetic susceptibility for the magnetic field applied perpendicular (χ ab) and parallel (χ c) to themore » crystalline c-axis is very anisotropic, and the susceptibility ratio (χ ab/χ c) reaches a maximum value of 10, indicating that the spin easy axis is within the Ce plane. The entropy recovered at T N is consistent with the doublet ground state of the crystal field split J = 5/2 multiplet of Ce 3+ ions.« less

Synthesis and characterization of the heavy-fermion compound CePtAl 4Ge 2

DOE PAGES

Shin, Soohyeon; Rosa, Priscila Ferrari Silveira; Ronning, Filip; ...

2017-12-18

Here, we report the synthesis of the Ce-based quaternary compound CePtAl 4Ge 2 that crystallizes in the trigonal structure (space group R 3¯m, 166) with unit cell parameters, a = 4.1995(5) Å, c = 31.851(7) Å, and γ = 120°. Powder X-ray diffraction and energy dispersive X-ray spectroscopy show that CePtAl 4Ge 2 (LaPtAl 4Ge 2) is in a single, homogeneous phase. Magnetic susceptibility, electrical resistivity, and heat capacity measurements of CePtAl 4Ge 2 show that it exhibits antiferromagnetic behavior below 2.3 K. The magnetic susceptibility for the magnetic field applied perpendicular (χ ab) and parallel (χ c) to themore » crystalline c-axis is very anisotropic, and the susceptibility ratio (χ ab/χ c) reaches a maximum value of 10, indicating that the spin easy axis is within the Ce plane. The entropy recovered at T N is consistent with the doublet ground state of the crystal field split J = 5/2 multiplet of Ce 3+ ions.« less

New chemical constituents from Oryza sativa straw and their algicidal activities against blue-green algae.

PubMed

Ahmad, Ateeque; Kim, Seung-Hyun; Ali, Mohd; Park, Inmyoung; Kim, Jin-Seog; Kim, Eun-Hye; Lim, Ju-Jin; Kim, Seul-Ki; Chung, Ill-Min

2013-08-28

Five new constituents, 5,4'-dihydroxy-7,3'-dimethoxyflavone-4'-O-β-D-xylopyranosyl-(2a→1b)-2a-O-β-D-xylopyranosyl-(2b→1c)-2b-O-β-D-xylopyranosyl-2c-octadecanoate (1), 5,4'-dihydroxy-7,3'-dimethoxyflavone-4'-O-α-D-xylopyranosyl-(2a→1b)-2a-O-α-D-xylopyranosyl-(2b→1c)-2b-O-α-D-xylopyranosyl-(2c→1d)-2c-O-α-D-xylopyranosyl-2d-octadecanoate (2), kaempferol-3-O-α-D-xylopyranosyl-(2a→1b)-2a-O-α-D-xylopyranosyl-(2b→1c)-2b-O-α-D-xylopyranosyl-(2c→1d)-2c-O-α-D-xylopyranosyl-2d-hexadecanoate (3), methyl salicylate-2-O-α-D-xylopyranosyl-(2a→1b)-2a-O-α-D-xylopyranosyl-(2b→1c)-2b-O-α-D-xylopyranosyl-(2c→1d)-2c-O-α-D-xylopyranosyl-(2d→1e)-2d-O-α-D-xylopyranosyl-(2e→1f)-2e-O-α-D-xylopyranosyl-(2f→1g)-2f-O-α-D-xylopyranosyl-(2g→1h)-2g-O-α-D-xylopyranosyl-2h-geranilan-8',10'-dioic acid-1'-oate (4), and oleioyl-β-D-arabinoside (5), along with eight known compounds, were isolated from a methanol extract of Oryza sativa straw. The structures of the new compounds were elucidated using one- and two-dimensional NMR spectroscopies in combination with IR, ESI/MS, and HR-ESI/FTMS. In bioassays with blue-green algae, the efficacies of the algicidal activities of the five new compounds (1-5) were evaluated at concentrations of 1, 10, and 100 mg/L. Compound 5 had the highest growth inhibition (92.6 ± 0.3%) for Microcystis aeruginosa UTEX 2388 at a concentration of 100 ppm (mg/L). Compound 5 has high potential for the ecofriendly control of weeds and algae harmful to water-logged rice.

Laboratory Studies of Stabilities of Heterocyclic Aromatic Molecules: Suggested Gas Phase Ion-Molecule Routes to Production in Interstellar Gas Clouds

NASA Technical Reports Server (NTRS)

Adams, Nigel G.; Fondren, L. Dalila; McLain, Jason L.; Jackson, Doug M.

2006-01-01

Several ring compounds have been detected in interstellar gas clouds, ISC, including the aromatic, benzene. Polycyclic aromatic hydrocarbons, PAHs, have been implicated as carriers of diffuse interstellar bands (DIBs) and unidentified infrared (UIR) bands. Heterocyclic aromatic rings of intermediate size containing nitrogen, possibly PreLife molecules, were included in early searches but were not detected and a recent search for Pyrimidine was unsuccessful. Our laboratory investigations of routes to such molecules could establish their existence in ISC and suggest conditions under which their concentrations would be maximized thus aiding the searches. The stability of such ring compounds (C5H5N, C4H4N2, C5H11N and C4H8O2) has been tested in the laboratory using charge transfer excitation in ion-molecule reactions. The fragmentation paths, including production of C4H4(+), C3H3N(+) and HCN, suggest reverse routes to the parent molecules, which are presently under laboratory investigation as production sources.

Fourier transform infrared study of the phase transitions in (NH4)3VO2FO4

NASA Astrophysics Data System (ADS)

de Waal, D.; Heyns, A. M.

1994-01-01

Ammonium oxofluorovanadate compounds are known to show some potential as ferroelectric materials. The whole series of ammonium and sodium oxofluorovanadate compounds including Na3VO2F4 have already been prepared and investigated by means of various techniques including x-ray diffraction, EPR, and vibrational spectroscopy. It was established that the pure ammonium compound shows the two above mentioned transitions from phase A (below 200 K) to phase B (between 200 and 400 K) and phase C (above 400 K) while Na(NH4)2VO2F4 has only one transition from phase A to phase B around 400 K4. In the present study various aspects regarding the nature of the structures of (NH4)3VO2F3 and Na(NH4)2VO2F4 and its influence on the phase transitions have been investigated.

Antitumor Compounds from the Stout Camphor Mushroom Taiwanofungus camphoratus (Higher Basidiomycetes) Spent Culture Broth.

PubMed

Jia, Wei; Bai, Yan-Yan; Zhang, Zhong; Feng, Na; Feng, Jie; Yan, Meng-Qiu; Zhu, Li-Na; Jia, Xin-Cheng; Wang, Ming-Dao; Zhang, Jing-song; Fan, Hua

2015-01-01

A known compound, 5-(hydroxymethyl) furan-2-carbaldehyde, and a novel compound, 3-isobutyl-1-methoxy-4-(4'-(3-methylbut-2-enyloxy)phenyl)-1H-pyrrole-2,5-dione were isolated from spent broth from submerged cultures of Taiwanofungus camphoratus. Their structures were elucidated by nuclear magnetic resonance (1H, 13C, and 2D) and mass spectra. These compounds inhibited the proliferation of K562 and HepG2 tumor cells in vitro.

40 CFR 60.542 - Standards for volatile organic compounds.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Rubber Tire Manufacturing Industry § 60.542 Standards for volatile organic compounds. (a) On and after... duration of the compliance period: (A) 3,870 kg (8,531 lb) of VOC per 28 days, (B) 4,010 kg (8,846 lb) of VOC per 29 days, (C) 4,150 kg (9,149 lb) of VOC per 30 days, (D) 4,280 kg (9,436 lb) of VOC per 31...

Behavioral and neurochemical pharmacology of six psychoactive substituted phenethylamines: mouse locomotion, rat drug discrimination and in vitro receptor and transporter binding and function.

PubMed

Eshleman, Amy J; Forster, Michael J; Wolfrum, Katherine M; Johnson, Robert A; Janowsky, Aaron; Gatch, Michael B

2014-03-01

Psychoactive-substituted phenethylamines 2,5-dimethoxy-4-chlorophenethylamine (2C-C); 2,5-dimethoxy-4-methylphenethylamine (2C-D); 2,5-dimethoxy-4-ethylphenethylamine (2C-E); 2,5-dimethoxy-4-iodophenethylamine (2C-I); 2,5-dimethoxy-4-ethylthiophenethylamine (2C-T-2); and 2,5-dimethoxy-4-chloroamphetamine (DOC) are used recreationally and may have deleterious side effects. This study compares the behavioral effects and the mechanisms of action of these substituted phenethylamines with those of hallucinogens and a stimulant. The effects of these compounds on mouse locomotor activity and in rats trained to discriminate dimethyltryptamine, (-)-DOM, (+)-LSD, (±)-MDMA, and S(+)-methamphetamine were assessed. Binding and functional activity of the phenethylamines at 5-HT1A, 5-HT2A, 5-HT2C receptors and monoamine transporters were assessed using cells heterologously expressing these proteins. The phenethylamines depressed mouse locomotor activity, although 2C-D and 2C-E stimulated activity at low doses. The phenethylamines except 2C-T-2 fully substituted for at least one hallucinogenic training compound, but none fully substituted for (+)-methamphetamine. At 5-HT1A receptors, only 2C-T-2 and 2C-I were partial-to-full very low potency agonists. In 5-HT2A arachidonic acid release assays, the phenethylamines were partial to full agonists except 2C-I which was an antagonist. All compounds were full agonists at 5-HT2A and 5-HT2C receptor inositol phosphate assays. Only 2C-I had moderate affinity for, and very low potency at, the serotonin transporter. The discriminative stimulus effects of 2C-C, 2C-D, 2C-E, 2C-I, and DOC were similar to those of several hallucinogens, but not methamphetamine. Additionally, the substituted phenethylamines were full agonists at 5-HT2A and 5-HT2C receptors, but for 2C-T-2, this was not sufficient to produce hallucinogen-like discriminative stimulus effects. Additionally, the 5-HT2A inositol phosphate pathway may be important in 2C-I's psychoactive properties.

Behavioral and neurochemical pharmacology of six psychoactive substituted phenethylamines: Mouse locomotion, rat drug discrimination and in vitro receptor and transporter binding and function

PubMed Central

Eshleman, Amy J.; Forster, Michael J.; Wolfrum, Katherine M.; Johnson, Robert A.; Janowsky, Aaron; Gatch, Michael B.

2014-01-01

Rationale Psychoactive substituted phenethylamines 2,5-dimethoxy-4-chlorophenethylamine (2C-C); 2,5-dimethoxy-4-methylphenethylamine (2C-D); 2,5-dimethoxy-4-ethylphenethylamine (2C-E); 2,5-dimethoxy-4-iodophenethylamine (2C-I); 2,5-dimethoxy-4-ethylthiophenethylamine (2C-T-2) and 2,5-dimethoxy-4-chloroamphetamine (DOC) are used recreationally and may have deleterious side effects. Objectives This study compares behavioral effects and mechanisms of action of these substituted phenethylamines with those of hallucinogens and a stimulant. Methods The effects of these compounds on mouse locomotor activity and in rats trained to discriminate dimethyltryptamine, (−)DOM, (+)LSD, (±)MDMA and (S+)methamphetamine were assessed. Binding and functional activity of the phenethylamines at 5-HT1A, 5-HT2A, 5-HT2C receptors and monoamine transporters were assessed using cells heterologously expressing these proteins. Results The phenethylamines depressed mouse locomotor activity, although 2C-D and 2C-E stimulated activity at low doses. The phenethylamines except 2C-T-2 fully substituted for at least one hallucinogenic training compound but none fully substituted for (+)-methamphetamine. At 5-HT1A receptors, only 2C-T-2 and 2C-I were partial-to-full very low potency agonists. In 5-HT2A arachidonic acid release assays, the phenethylamines were partial to full agonists except 2C-I which was an antagonist. All compounds were full agonists at 5-HT2A and 5-HT2C receptor inositol phosphate assays. Only 2C-I had moderate affinity for, and very low potency at, the serotonin transporter. Conclusions The discriminative stimulus effects of 2C-C, 2C-D, 2C-E, 2C-I and DOC were similar to those of several hallucinogens but not methamphetamine. Additionally, the substituted phenethylamines were full agonists at 5-HT2A and 5-HT2C receptors, but for 2C-T-2, this was not sufficient to produce hallucinogenlike discriminative stimulus effects. Additionally, the 5-HT2A inositol phosphate pathway may be important in 2C-I’s psychoactive properties. PMID:24142203

Synthesis, crystal structures and theoretical calculations of new 1-[2-(5-chloro-2-benzoxazolinone-3-yl)acetyl]-3,5-diphenyl-4,5-dihydro-(1H)-pyrazoles

NASA Astrophysics Data System (ADS)

Gökşen, Umut Salgın; Alpaslan, Yelda Bingöl; Kelekçi, Nesrin Gökhan; Işık, Şamil; Ekizoğlu, Melike

2013-05-01

1-[2-(5-Chloro-2-benzoxazolinone-3-yl)acetyl]-3-phenyl-5-(3-methoxyphenyl)-4,5-dihydro-(1H)-pyrazole (5a), 1-[2-(5-chloro-2-benzoxazolinone-3-yl)acetyl]-3-phenyl-5-(3,4-dimethoxyphenyl)-4,5-dihydro-(1H)-pyrazole (5b) and 1-[2-(5-chloro-2-benzoxazolinone-3-yl)acetyl]-3-(4-methylphenyl)-5-(2,3-dimethoxyphenyl)-4,5-dihydro-(1H)-pyrazole (5c) were synthesized. The crystal and molecular structures of the compounds 5a, 5b and 5c were determined by elemental analyses, IR, 1H NMR, ESI-MS and single-crystal X-ray diffraction. DFT method with 6-31G(d,p) basis set was used to calculate the optimized geometrical parameters, vibrational frequencies and chemical shift values. The calculated vibrational frequencies and chemical shift values were compared with experimental IR and 1H NMR values. The results represented that there was a good agreement between experimental and calculated values of the compounds 5a-5c. In addition, DFT calculations of the compounds, molecular electrostatic potentials (MEPs) and frontier molecular orbitals were performed at B3LYP/6-31G(d,p) level of theory. Furthermore, compounds were tested against three Gram-positive bacteria: Staphylococcus aureus ATCC 29213 (American Type Culture Collection), methicillin resistant S. aureus (MRSA) ATCC 43300 and Enterococcus faecalis ATCC 29212; two Gram negative bacteria: Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853; and three fungi: Candida albicans ATCC 90028, Candida krusei ATCC 6258 and Candida parapsilosis ATCC 90018. In general, all of the compounds were found to be slightly active against tested microorganisms.

Synthesis and properties of 4-alkoxy-2-[2-hydroxy-3-(4-o,m,p-halogenoaryl-1 -piperazinyl)propyl]-6-methyl-1H-pyrrolo-[3,4-c]pyridine-1,3(2H)-diones with analgesic and sedative activities.

PubMed

Sladowska, Helena; Sabiniarz, Aleksandra; Szkatuła, Dominika; Filipek, Barbara; Sapa, Jacek

2006-01-01

Synthesis of N-substituted derivatives of 4-alkoxy-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones (17-26) is described. The chlorides, containing OH group, used in the above synthesis can exist in two isomeric forms: chain (12, 14-16) and cyclic (12a, 14a-16a). All final imides studied exhibited analgesic activity in the "writhing syndrome" test which was superior than that of acetylsalicylic acid. In the "hot plate" test only two compounds (19, 20) were active as antinociceptive agents. Furthermore, all compounds tested significantly suppressed the spontaneous locomotor activity of mice.

High-pressure investigations of yttrium(III) oxoarsenate(V): Crystal structure and luminescence properties of Eu3+-doped scheelite-type Y[AsO4] from xenotime-type precursors

NASA Astrophysics Data System (ADS)

Ledderboge, Florian; Nowak, Jan; Massonne, Hans-Joachim; Förg, Katharina; Höppe, Henning A.; Schleid, Thomas

2018-07-01

Colourless, water- and air-stable single crystals of yttrium(III) oxoarsenate(V) Y[AsO4] in the xenotime-type crystal structure were prepared by the reaction of yttrium sesquioxide (Y2O3) dissolved in aqueous nitric acid (13%) with a solution of arsenic(V) oxide hydrate (As2O5·3H2O) and subsequent neutralization with 1 M caustic soda. Y[AsO4] crystallizes tetragonally in the space group I41/amd with the lattice parameters a = 704.63(6) and c = 628.94(5) pm for Z = 4 and is isotypic to the minerals xenotime RE[PO4] (RE: mainly Y and Yb) and chernovite RE[AsO4] (RE: mainly Y and Ce). This xenotime-type yttrium compound was used as precursor in a high-pressure experiment (20 kbar) at 700 °C to create a new tetragonal modification of Y[AsO4]. It shows the scheelite-type structure (space group: I41/a) with the lattice parameters a = 498.23(4) and c = 1120.71(9) pm for Z = 4, named after the mineral scheelite (Ca[WO4]). Both tetragonal structures are characterized by only one crystallographically unique position for each of the Y3+, As5+ and O2- ions with distances of d(Y-O) = 232 and 241 pm (C.N. = 8) as well as d(As-O) = 169 pm (C.N. = 4) in the case of the scheelite-type structure. The xenotime-type compound shows an unexpected slight decrease in average bond lengths for the yttrium to oxygen (d(Y-O) = 230 and 241 pm, C.N. = 8) as well as for the arsenic to oxygen distances (d(As-O) = 168 pm, C.N. = 4), accompanied by a drastic density increase from Dx = 4.85 (xenotime type) to Dx = 5.44 g • cm-3 (scheelite type). Luminescence spectroscopic measurements of the Eu3+-doped Y[AsO4] samples, obtained in experiments at similar conditions as for the pure compounds, show a bright, reddish lighting for the scheelite type, which does not occur for the xenotime type of yttrium(III) oxoarsenate(V).

Variations of Leaf Cuticular Waxes Among C3 and C4 Gramineae Herbs.

PubMed

He, Yuji; Gao, Jianhua; Guo, Na; Guo, Yanjun

2016-11-01

Modern C4 plants are commonly distributed in hot and dry environments whereas C3 plants predominate in cool and shade areas. At the outmost of plant surface, the deposition and chemical composition of cuticular waxes vary under different environmental conditions. However, whether such variation of cuticular wax is related to the distribution of C3 and C4 under different environmental conditions is still not clear. In this study, leaves of six C3 Gramineae herbs distributed in spring, Roegneria kamoji, Polypogon fugax, Poa annua, Avena fatua, Alopecurus aequalis, and Oplismenus undulatifolius, and four C4 and one C3 Gramineae herbs distributed in summer, Digitaria sanguinalis, Eleusine indica, Setaria viridis, S. plicata, and O. undulatifolius, were sampled and analyzed for cuticular wax. Plates were the main epicuticular wax morphology in both C3 and C4 plants except S. plicata. The plates melted in C4 plants but not in C3 plants. The total cuticular wax amounts in C4 plants were significantly lower than those in C3 plants, except for O. undulatifolius. Primary alcohols were the most abundant compounds in C3 plants, whereas n-alkanes were relatively the most abundant compounds in C4 plants. C 29 was the most abundant n-alkane in C3 plants except for O. undulatifolius, whereas the most abundant n-alkane was C 31 or C 33 in C4 plants. The average chain length (ACL) of n-alkanes was higher in C4 than in C3 plants, whereas the ACL of n-alkanoic acids was higher in C3 than C4 plants. The cluster analysis based on the distribution of n-alkanes clearly distinguished C3 and C4 plants into two groups, except for O. undulatifolius which was grouped with C4 plants. These results suggest that the variations of cuticular waxes among C3 and C4 Gramineae herbs are related to the distribution of C3 and C4 plants under different environmental conditions. © 2016 Wiley-VHCA AG, Zurich, Switzerland.

An expedient synthesis of N-(1-(5-mercapto-4-((substituted benzylidene)amino)-4H-1,2,4-triazol-3-yl)-2-phenylethyl)benzamides as jack bean urease inhibitors and free radical scavengers: Kinetic mechanism and molecular docking studies.

PubMed

Saeed, Aamer; Larik, Fayaz Ali; Channar, Pervaiz Ali; Mehfooz, Haroon; Ashraf, Mohammad Haseeb; Abbas, Qamar; Hassan, Mubashir; Seo, Sung-Yum

2017-11-01

In this study, some new azomethine-triazole hybrids 5a-5l derived from N-benzoyl-L-phenylalanine were synthesized and characterized. The synthesized compounds showed first-rate, urease inhibition, and compounds 5c and 5e were found to be most effective inhibitors with 0.0137 ± 0.00082 μm and 0.0183 ± 0.00068 μm, respectively (thiourea 15.151 ± 1.27 μm). The kinetic mechanism of urease inhibition revealed the compounds 5c and 5e to be non-competitive inhibitors, whereas compounds 5d and 5j were found to be of mixed-type inhibitors. Docking studies also indicated better interaction patterns with urease enzyme. The results of enzyme inhibition, kinetic mechanism and molecular docking suggest that these compounds can serve as lead compounds in the design of more effective urease inhibitors. © 2017 John Wiley & Sons A/S.

Synthesis, Structure and Thermal Behavior of Oxalato-Bridged Rb+ and H3O+ Extended Frameworks with Different Dimensionalities

PubMed Central

Kherfi, Hamza; Hamadène, Malika; Guehria-Laïdoudi, Achoura; Dahaoui, Slimane; Lecomte, Claude

2010-01-01

Correlative studies of three oxalato-bridged polymers, obtained under hydrothermal conditions for the two isostructural compounds {Rb(HC2O4)(H2C2O4)(H2O)2}∞1, 1, {H3O(HC2O4)(H2C2O4).2H2O}∞1, 2, and by conventional synthetic method for {Rb(HC2O4)}∞3, 3, allowed the identification of H-bond patterns and structural dimensionality. Ferroïc domain structures are confirmed by electric measurements performed on 3. Although 2 resembles one oxalic acid sesquihydrate, its structure determination doesn’t display any kind of disorder and leads to recognition of a supramolecular network identical to hybrid s-block series, where moreover, unusual H3O+ and NH4+ similarity is brought out. Thermal behaviors show that 1D frameworks with extended H-bonds, whether with or without a metal center, have the same stability. Inversely, despite the dimensionalities, the same metallic intermediate and final compounds are obtained for the two Rb+ ferroïc materials.

Synthesis of carbon-11 labeled 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinolinium derivatives as new potential PET SKCa channel imaging agents.

PubMed

Gao, Mingzhang; Wang, Min; Zheng, Qi-Huang

2008-02-01

Small conductance Ca2+-activated K+ (SKCa) channels play an important role in many functions such as neuronal communication and behavioral plasticity, secretion, and cell proliferation. SKCa channel modulation is associated with various brain, heart, and cancer diseases. N-methyl-laudanosine and its structurally related derivatives, substituted 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums, are reversible and selective SKCa channel blockers. Carbon-11 labeled N-methyl-laudanosine and its tetrahydroisoquinolinium derivatives may serve as new probes for positron emission tomography (PET) to image SKCa channels in the brain, heart, and cancer. The key intermediates, substituted isoquinolines (3a-c), were synthesized using a modification of the Pomeranz-Fritsch procedure. The precursors, substituted 1-(3,4-dimethoxybenzyl)-2-methyl-1,2,3,4-tetrahydroisoquinolines (8a-c), and their corresponding reference standards, substituted 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums (9a-c), were synthesized from compounds 3a-c with 3,4-dimethoxybenzyl chloride (2) in multiple steps with moderate to excellent chemical yields. The precursor 6,7-dimethoxy-1-(3,4-dimethoxybenzyl)-2-methyl-1,2,3,4-tetrahydroisoquinoline (10) was commercially available, and the methylation of compound 10 with methyl iodide provided N-methyl-laudanosine (11). The target quaternary ammonium tracers, carbon-11 labeled 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums ([11C]9a-c and [11C]11), were prepared by N-[11C]methylation of the tertiary amine precursors (8a-c and 10) with [11C]methyl triflate and isolated by a simplified solid-phase extraction (SPE) purification using a SiO2 or cation-exchange CM Sep-Pak cartridge in 40-65% radiochemical yields.

Bioactive Steroids with Methyl Ester Group in the Side Chain from a Reef Soft Coral Sinularia brassica Cultured in a Tank.

PubMed

Huang, Chiung-Yao; Su, Jui-Hsin; Liaw, Chih-Chuang; Sung, Ping-Jyun; Chiang, Pei-Lun; Hwang, Tsong-Long; Dai, Chang-Feng; Sheu, Jyh-Horng

2017-09-01

A c ontinuing chemical investigation of the ethyl acetate (EtOAc) extract of a reef soft coral Sinularia brassica , which was cultured in a tank, afforded four new steroids with methyl ester groups, sinubrasones A-D (1-4) for the first time. In particular, 1 possesses a β-D-xylopyranose. The structures of the new compounds were elucidated on the basis of spectroscopic analyses. The cytotoxicities of compounds 1-4 against the proliferation of a limited panel of cancer cell lines were assayed. The anti-inflammatory activities of these new compounds 1-4 were also evaluated by measuring their ability to suppress superoxide anion generation and elastase release in N -formyl-methionyl-leucyl-phenylalanine/cytochalasin B (fMLP/CB)-induced human neutrophils. Compounds 2 and 3 were shown to exhibit significant cytotoxicity, and compounds 3 and 4 were also found to display attracting anti-inflammatory activities.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lichtscheidl, Alejandro G.; Janicke, Michael T.; Scott, Brian L.

The synthesis and full characterization, including Nuclear Magnetic Resonance (NMR) data ( 1H, 13C{ 1H} and 119Sn{ 1H}), for a series of Me 3SnX (X = O-2,6-tBu 2C 6H 3 (1), (Me 3Sn)N(2,6- iPr 2C 6H 3) (3), NH-2,4,6- tBu 3C 6H 2 (4), N(SiMe 3) 2 (5), NEt 2, C 5Me 5 (6), Cl, Br, I, and SnMe 3) compounds in benzene-d 6, toluene-d 8, dichloromethane-d 2, chloroform-d 1, acetonitrile-d 3, and tetrahydrofuran-d 8 are reported. The X-ray crystal structures of Me 3Sn(O-2,6- tBu 2C 6H 3) (1), Me 3Sn(O-2,6- iPr 2C 6H 3) (2), and (Me 3Sn)(NH-2,4,6- tBumore » 3C 6H 2) (4) are also presented. As a result, these compiled data complement existing literature data and ease the characterization of these compounds by routine NMR experiments.« less

Spectroscopic studies and structure of 3-methoxy-2 -[(2,4,4,6,6-pentachloro-1,3,5,2{lambda}{sup 5},4{lambda}{sup 5},6{lambda}{sup 5}-triazatriphosphin-2-yl)oxy] benzaldehyde

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oezay, H.; Yildiz, M., E-mail: myildiz@comu.edu.tr; Uenver, H.

2013-01-15

The compound called 3-methoxy-2- [(2,4,4,6,6-pentachloro-1,3,5,2{lambda}{sup 5},4{lambda}{sup 5},6{lambda}{sup 5}-triazatriphosphin-2-yl)oxy] benzaldehyde has been synthesized from the reaction of 2-hydroxy-3-methoxybenzaldehyde with hexachlorocyclotriphosphazene. It has been characterized by elemental analysis, MS, IR, {sup 1}H NMR, {sup 13}C NMR, {sup 31}P NMR and UV-visible spectroscopic techniques. The structure of the title compound has been determind by X-ray analysis. Crystals are orthorhombic, space group P2{sub 1}2{sub 1}2{sub 1}, Z = 4, a = 7.705(1), b = 12.624(1), c = 17.825(2) A, R{sub 1} = 0.0390 and wR{sub 2} = 0.1074 [I > 2{sigma}(I)], respectively.

Molecular Basis of Microbial One-Carbon Metabolism 2008 Gordon Research Conference (July 20-25, 2008)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stephen W. Ragsdale

2009-08-12

One-carbon (C-1) compounds play a central role in microbial metabolism. C-1 compounds include methane, carbon monoxide, CO2, and methanol as well as coenzyme-bound one-carbon compounds (methyl-B12, CH3-H4folate, etc). Such compounds are of broad global importance because several C-1 compounds (e.g., CH4) are important energy sources, some (e.g., CO2 and CH4) are potent greenhouse gases, and others (e.g., CH2Cl2) are xenobiotics. They are central in pathways of energy metabolism and carbon fixation by microbes and many are of industrial interest. Research on the pathways of one-carbon metabolism has added greatly to our understanding of evolution, structural biology, enzyme mechanisms, gene regulation,more » ecology, and applied biology. The 2008 meeting will include recent important findings in the following areas: (a) genomics, metagenomics, and proteomic studies that have expanded our understanding of autotrophy and C-1 metabolism and the evolution of these pathways; (b) redox regulation of carbon cycles and the interrelationship between the carbon cycle and other biogeochemical cycles (sulfur, nitrogen, oxygen); (c) novel pathways for carbon assimilation; (d) biotechnology related to C-1 metabolism; (e) novel enzyme mechanisms including channeling of C-1 intermediates during metabolism; and (f) the relationship between metal homeostasis and the global carbon cycle. The conference has a diverse and gender-balanced slate of speakers and session leaders. The wide variety of disciplines brought to the study of C-1 metabolism make the field an excellent one in which to train young researchers.« less

One-pot microwave assisted stereoselective synthesis of novel dihydro-2'H-spiro[indene-2,1'-pyrrolo-[3,4-c]pyrrole]-tetraones and evaluation of their antimycobacterial activity and inhibition of AChE.

PubMed

Bharkavi, Chelliah; Vivek Kumar, Sundaravel; Ashraf Ali, Mohamed; Osman, Hasnah; Muthusubramanian, Shanmugam; Perumal, Subbu

2017-07-15

An efficient one-pot microwave assisted stereoselective synthesis of novel dihydro-2'H-spiro[indene-2,1'-pyrrolo[3,4-c]pyrrole]-tetraone derivatives through three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ from ninhydrin and sarcosine with a series of 1-aryl-1H-pyrrole-2,5-diones is described. The synthesised compounds were screened for their antimycobacterial and AChE inhibition activities. Compound 4b (IC 50 1.30µM) has been found to display twelve fold antimycobacterial activity compared to cycloserine and it is thirty seven times more active than pyrimethamine. Compound 4h displays maximum AchE inhibitory activity with IC 50 value of 0.78±0.01µmol/L. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthetic, Infrared, 1H and 13C NMR Spectral Studies on N-(2-/3-Substituted Phenyl)-4-Substituted Benzenesulphonamides, 4-X'C6H4SO2NH(2-/3-XC6H4), where X' = H, CH3, C2H5, F, Cl or Br, and X = CH3 or Cl

NASA Astrophysics Data System (ADS)

Gowda, B. Thimme; Shetty, Mahesha; Jayalakshmi, K. L.

2005-02-01

Twenty three N-(2-/3-substituted phenyl)-4-substituted benzenesulphonamides of the general formula, 4-X'C6H4SO2NH(2-/3-XC6H4), where X' = H, CH3, C2H5, F, Cl or Br and X = CH3 or Cl have been prepared and characterized, and their infrared spectra in the solid state, 1H and 13C NMR spectra in solution were studied. The N-H stretching vibrations, νN-H, absorb in the range 3285 - 3199 cm-1, while the asymmetric and symmetric SO2 vibrations vary in the ranges 1376 - 1309 cm-1 and 1177 - 1148 cm-1, respectively. The S-N and C-N stretching vibrations absorb in the ranges 945 - 893 cm-1 and 1304 - 1168 cm-1, respectively. The compounds do not exhibit particular trends in the variation of these frequencies on substitution either at ortho or meta positions with either a methyl group or Cl. The observed 1H and 13C chemical shifts of are assigned to protons and carbons of the two benzene rings. Incremental shifts of the ring protons and carbons due to -SO2NH(2-/3-XC6H4) groups in C6H5SO2NH(2-/3-XC6H4), and 4- X'C6H4SO2- and 4-X'C6H4SO2NH- groups in 4-X'C6H4SO2NH(C6H5) are computed and employed to calculate the chemical shifts of the ring protons and carbons in the substituted compounds, 4-X'C6H4SO2NH(2-/3-XC6H4). The computed values agree well with the observed chemical shifts.

Isomorphous rare-earth bis[bis(2,6-diisopropylphenyl)phosphate] complexes and their self-assembly into two-dimensional frameworks by intramolecular hydrogen bonds.

PubMed

Minyaev, Mikhail E; Nifant'ev, Ilya E; Tavtorkin, Alexander N; Korchagina, Sof'ya A; Zeynalova, Shadana Sh; Ananyev, Ivan V; Churakov, Andrei V

2017-10-01

The crystal structures of rare-earth diaryl- or dialkylphosphate derivatives are poorly explored. Crystals of bis[bis(2,6-diisopropylphenyl)phosphato-κO]chloridotetrakis(methanol-κO)neodymium methanol disolvate, [Nd(C 24 H 34 O 4 P)Cl(CH 4 O) 4 ]·2CH 3 OH, (1), and of the lutetium, [Lu(C 24 H 34 O 4 P)Cl(CH 4 O) 4 ]·2CH 3 OH, (2), and yttrium, [Y(C 24 H 34 O 4 P)Cl(CH 4 O) 4 ]·2CH 3 OH, (3), analogues have been obtained by reactions between lithium bis(2,6-diisopropylphenyl)phosphate and LnCl 3 (H 2 O) 6 (in a 2:1 ratio) in methanol. Compounds (1)-(3) crystallize in the C2/c space group. Their crystal structures are isomorphous. The molecule possesses C 2 symmetry with a twofold crystallographic axis passing through the Ln and Cl atoms. The bis(2,6-diisopropylphenyl)phosphate ligands all display a κ 1 O-monodentate coordination mode. The coordination polyhedron for the metal atom [coordination number (CN) = 7] is a distorted pentagonal bipyramid. Each [Ln{O 2 P(O-2,6- i Pr 2 C 6 H 3 ) 2 } 2 Cl(CH 3 OH) 4 ] molecular unit exhibits two intramolecular O-H...O hydrogen bonds, forming six-membered rings, and two intramolecular O-H...Cl interactions, forming four-membered rings. Intermolecular O-H...O hydrogen bonds connect each unit via four noncoordinating methanol molecules with four other units, forming a two-dimensional hydrogen-bond network. Crystals of bis[bis(2,6-diisopropylphenyl)phosphato-κO]tetrakis(methanol-κO)(nitrato-κ 2 O,O')neodymium methanol disolvate, [Nd(C 24 H 34 O 4 P)(NO 3 )(CH 4 O) 4 ]·2CH 3 OH, (4), have been obtained in an analogous manner from NdCl 3 (H 2 O) 6 . Compound (4) also crystalizes in the C2/c space group. Its crystal structure is similar to those of (1)-(3). The κ 2 O,O'-bidentate nitrate anion is disordered over a twofold axis, being located nearly on it. Half of the molecule is crystallographically unique (CN Nd = 8). Unlike (1)-(3), complex (4) exhibits disorder of all three methanol molecules, one isopropyl group of the phosphate ligand and the NO 3 - ligand. The structure of (4) displays intra- and intermolecular O-H...O hydrogen bonds similar to those in (1)-(3). Compounds (1)-(4) represent the first reported mononuclear bis[bis(diaryl/dialkyl)phosphate] rare-earth complexes.

Crystal structure, Hirshfeld surfaces computational study and physicochemical characterization of the hybrid material (C7H10N)2[SnCl6]·H2O

NASA Astrophysics Data System (ADS)

BelhajSalah, S.; Abdelbaky, Mohammed S. M.; García-Granda, Santiago; Essalah, K.; Ben Nasr, C.; Mrad, M. L.

2018-01-01

A novel hybrid compound, bis(4-methylanilinium)hexachlorostannate(IV) monohydrate, formulated as (C7H10N)2[SnCl6]·H2O, has been prepared and characterized by powder and single crystal X-ray diffraction (XRD), Hirshfeld surface analysis, infrared spectroscopy (IR), optical study, differential thermal analysis(DTA) and X-ray photoelectron spectroscopy analysis (XPS). The title compound crystallizes in the monoclinic space group P21/c with a = 13.093(1)Å, b = 7.093(6)Å, c = 24.152(2)Å, β = 98.536(4)⁰ and V = 2218.4(4) Å3. Their crystal structure exhibits alternating inorganic layers parallel to the (ab) plane at z = n/2. The different entities, [SnCl6]2-, organic cations and water molecules, are connected via hydrogen bonds to form a three-dimensional network. The powder XRD data confirms the phase purity of the crystalline sample. The intermolecular interactions were investigated by Hirshfeld surfaces. The vibrational absorption bands were identified by IR spectroscopy and have been discussed. The optical properties of the crystal were studied by using optical absorption, UV-visible absorption and photoluminescence spectroscopy studies. The compound was also characterized by DTA to determine its thermal behavior with respect to the temperature. Finally, XPS technique is reported for analyzing the surface chemistry of this compound.

Microbial transformation of ginsenoside Rb1 to compound K by Lactobacillus paralimentarius.

PubMed

Quan, Lin-Hu; Kim, Yeon-Ju; Li, Guan Hao; Choi, Kwang-Tea; Yang, Deok-Chun

2013-06-01

In this study, the major ginsenoside Rb1 was transformed into the more pharmacologically active minor compound K by food grade Lactobacillus paralimentarius LH4, which was isolated from kimchi, a traditional Korean fermented food. The enzymatic reaction was analyzed by TLC, HPLC, and NMR. Using the cell-free enzyme of Lactobacillus paralimentarius LH4 at optimal conditions for 30 °C at pH 6.0, 1.0 mg ml(-1) ginsenoside Rb1 was transformed into 0.52 mg ml(-1) compound K within 72 h, with a corresponding molar conversion yield of 88 %. The cell-free enzyme hydrolyzed the two glucose moieties attached to the C-3 position and the outer glucose moiety attached to the C-20 position of the ginsenoside Rb1. The cell-free enzyme hydrolyzed the ginsenoside Rb1 along the following pathway: ginsenoside Rb1 → gypenoside XVII and ginsenoside Rd → ginsenoside F2 → compound K. Our results indicate that Lactobacillus paralimentarius LH4 has the potential to be applied for the preparation of compound K in the food industry.

Bioassay-guided isolation and evaluation of antimicrobial compounds from Ixora megalophylla against some oral pathogens.

PubMed

Panyo, J; Matsunami, K; Panichayupakaranant, P

2016-09-01

Context Ixora megalophylla Chamch. (Rubiaceae) is a new plant species recently found in southern Thailand. Ethyl acetate extracts of its leaves and stems showed antimicrobial activities. Objectives To isolate and identify the antimicrobial compounds from I. megalophylla leaves and stems. Materials and methods The dried leaves (1.7 kg) and stems (3.5 kg) were consecutively extracted with petroleum ether (5 L × 4), ethyl acetate (5 L × 3) and ethanol (5 L × 4) under reflux conditions. The ethyl acetate extract was subjected to an antimicrobial assay guided isolation with Candida albicans and Streptococcus mutans. Compounds 1-10 were identified by (1)H NMR, (13)C NMR and EI-MS. Minimal lethal concentration (MLC) against C. albicans and Streptococcus spp. was determined using a broth microdilution method for 48 and 24 h, respectively. Results and discussion On the basis of the antimicrobial assay guided isolation, 10 known compounds, including vanillic acid (1), syringic acid (2), 4-hydroxy benzaldehyde (3), scopoletin (4), loliolide (5), syringaldehyde (6), sinapaldehyde (7), coniferaldehyde (8), syringaresinol (9) and 2,2'-dithiodipyridine (10), were identified. Compounds 1-5 were purified from the ethyl acetate extract of the leaves, while 6-9 and 10 were from the ethyl acetate and ethanol extracts of the stems, respectively. Among these isolates, 10 showed the strongest antibacterial activities against S. mutans and Streptococcus mitis, with minimum inhibitory concentrations (MICs) of 2-4 μg/mL, and MLC of 4 μg/mL, as well as having a weak antifungal activity against C. albicans (MIC of 125 μg/mL). This is the first report of the antimicrobial activities of 10.

Quantum mechanical and spectroscopic (FT-IR, 13C, 1H NMR and UV) investigations of 2-(5-(4-Chlorophenyl)-3-(pyridin-2-yl)-4,5-dihydropyrazol-1-yl)benzo[d]thiazole by DFT method.

PubMed

Diwaker

2014-07-15

The electronic, NMR, vibrational, structural properties of a new pyrazoline derivative: 2-(5-(4-Chlorophenyl)-3-(pyridine-2-yl)-4,5-dihydropyrazol-1-yl)benzo[d]thiazole has been studied using Gaussian 09 software package. Using VEDA 4 program we have reported the PED potential energy distribution of normal mode of vibrations of the title compound. We have also reported the (1)H and (13)C NMR chemical shifts of the title compound using B3LYP level of theory with 6-311++G(2d,2p) basis set. Using time dependent (TD-DFT) approach electronic properties such as HOMO and LUMO energies, electronic spectrum of the title compound has been studied and reported. NBO analysis and MEP surface mapping has also been calculated and reported using ab initio methods. Copyright © 2014 Elsevier B.V. All rights reserved.

Highly Efficient Extraction of Phenolic Compounds by Use of Magnetic Room Temperature Ionic Liquids for Environmental Remediation

PubMed Central

Deng, Ning; Li, Min; Zhao, Lijie; Lu, Chengfei; de Rooy, Sergio L.; Warner, Isiah M.

2011-01-01

A hydrophobic magnetic room temperature ionic liquid (MRTIL), trihexyltetradecylphosphonium tetrachloroferrate(III) ([3C6PC14][FeCl4]), was synthesized from trihexyltetradecylphosphonium chloride and FeCl3·6H2O. This MRTIL was investigated as a possible separation agent for solvent extraction of phenolic compounds from aqueous solution. Due to its strong paramagnetism, [3C6PC14][FeCl4] responds to an external neodymium magnet, which was employed in the design of a novel magnetic extraction technique. The conditions for extraction, including extraction time, volume ratio between MRTIL and aqueous phase, pH of aqueous solution, and structures of phenolic compounds were investigated and optimized. The magnetic extraction of phenols achieved equilibrium in 20 min and the phenolic compounds were found to have higher distribution ratios under acidic conditions. In addition, it was observed that phenols containing a greater number of chlorine or nitro substitutents exhibited higher distribution ratios. For example, the distribution ratio of phenol (DPh) was 107. In contrast, 3,5-dichlorophenol distribution ratio (D3,5-DCP) had a much higher value of 6372 under identical extraction conditions. When compared with four selected traditional non-magnetic room temperature ionic liquids, our [3C6PC14][FeCl4] exhibited significantly higher extraction efficiency under the same experimental conditions used in this work. Pentachlorophenol, a major component in the contaminated soil sample obtained from a superfund site, was successfully extracted and removed by use of [3C6PC14][FeCl4] with high extraction efficiency. Pentachlorophenol concentration was dramatically reduced from 7.8 μg.mL−1 to 0.2 μg.mL−1 after the magnetic extraction by use of [3C6PC14][FeCl4]. PMID:21783320

Sensory and chemical investigations on the effect of oven cooking on warmed-over flavour development in chicken meat.

PubMed

Byrne, D V; Bredie, W L P; Mottram, D S; Martens, M

2002-06-01

Descriptive sensory profiling was carried out to evaluate the effect of oven-cooking temperature (160, 170, 180, 190 °C) on warmed-over flavour (WOF) development in cooked, chill-stored (at 4 °C for 0, 1, 2 and 4 days) and reheated chicken patties, derived from M. pectoralis major. In addition, gas chromatography-mass spectrometry (GC-MS) was carried out on a representative sub-set (160, 180, 190(o)C, stored at 4 °C for 0, 1, 4 days) of the meat samples used in sensory profiling. The effects of cooking and WOF in the sensory and chemical data were analysed using multivariate ANOVA-Partial Least Squares Regression (APLSR). Descriptive profiling indicated that WOF development was described by an increase of 'rancid' and 'sulphur/rubber' sensory notes and a concurrent decrease of chicken 'meaty' characteristics. Increasing cooking temperature resulted in meat samples with a more 'roasted', 'toasted' and 'bitter' sensory nature. Moreover, the 'roasted' character of the meat samples was also related to WOF development. Analysis of the volatile compounds from the chicken patties showed a rapid development of lipid oxidation derived compounds with chill-storage. Such compounds most likely contributed to the 'rancid' aspect of WOF development. Moreover, changes in sulphur-containing compounds were also related to WOF development and were proposed as additional participants in the lipid oxidation reactions. The sensory effects of these compounds were mainly described by the 'sulphur/rubber' note associated with WOF development. Overall, cooking temperature was found to increase the formation of Maillard-derived compounds, however, these did not appear to inhibit WOF development in the chicken patties.

[Chemical constituents of Jasminum giraldii and their antioxidant activity].

PubMed

Zhang, Xiu-Peng; Qin, Hui; Yang, Fang; Chai, Jiang; Wang, Xin; Song, Xiao-Mei; Mei, Qi-Bing; Feng, Feng; Yue, Zheng-Gang

2014-06-01

Ten compounds were isolated from the barks of Jasminum giraldii by means of various of chromatographic techniques such as silica gel, Sephadex LH-20 and Rp-HPLC. Their structures were identified by spectroscopic data analysis as (+)-medioresinol (1), (+) -syringaresinol (2), syringaresinol-4'-O-beta-D-glucopyranoside (3), oleanic acid (4), 3-methoxy-4-hydroxy-trans-cinnamaldehyde (5), trans-sinapaldehyde (6), syringaldehyde (7), 1-(4-methoxy -phenyl) -ethanol (8), trans-cinnamic acid (9), and 4-(1-methoxyethyl) -phenol (10). Among them, compounds 1-3, 5-8 and 10 were isolated from the J. genus for the first time and compounds 4 and 9 were obtained from J. giraldii for the first time. In the DPPH free radical scavenging assay, compound 1 exhibited significant activity (IC50 55.1 micromol x L(-1)), compared with vitamin C(IC50 59.9 micromol x L(-1)); and compound 2 showed moderate activity (IC50 79.0 micromol x L(-1)), compared with 2, 6-di-tert-butyl4-methylphenol (IC50 236 micromol x L(-1)).

A DSC and FTIR spectroscopic study of the effects of the epimeric 4-cholesten-3-ols and 4-cholesten-3-one on the thermotropic phase behaviour and organization of dipalmitoylphosphatidylcholine bilayer membranes: comparison with their 5-cholesten analogues.

PubMed

Benesch, Matthew G K; Mannock, David A; Lewis, Ruthven N A H; McElhaney, Ronald N

2014-01-01

We present the results of a comparative differential calorimetric and Fourier transform infrared spectroscopic study of the effect of cholesterol and five of its analogues on the thermotropic phase behaviour and organization of dipalmitoylphosphatidylcholine bilayer membranes. These sterols/steroids differ in both the nature and stereochemistry of the polar head group at C3 (βOH, αOH or C=O) and in the position of the double bond (C4-C5 in ring A or C5-C6 in ring B). In the three Δ(5) sterols/steroid series, the concentration of these compounds required to abolish the DPPC pretransition, inversely related to their relative ability to disorder gel state DPPC bilayers, decreases in the order βOH>αOH>C=O and these differences in concentration are significant. However, in the Δ(4) series, these concentrations are more similar, regardless of polar head group nature or stereochemistry. Similarly, the residual enthalpy of the main phase transition of DPPC at 50 mol.% sterol/steroid, which is inversely related to the miscibility of these compounds in the DPPC bilayer, also increases in the order βOH>αOH>C=O, but this effect is attenuated in the Δ(4) as opposed to the Δ(5) series. Both of these results indicate that the presence of a double bond at C4-C5 in ring A, as compared to a C5-C6 double bond in ring B, reduces the effect of variations in the structure of the polar group at C3 on the properties of the host DPPC bilayer. The movement of the double bond from C5 to C4 in the two sterol pairs results in a greater decrease in the temperature and enthalpy of both the pretransition and the main phase transition, whereas the opposite result is observed in the ketosteroid pair. Similarly, the ability of these compounds to order the DPPC hydrocarbon chains decreases in the order βOH>αOH>C=O in both series of compounds, but in the two sterol pairs, hydrocarbon chain ordering is greater for the Δ(5) than the Δ(4) sterols, whereas the opposite is the case for the steroid pair. All of these results indicate that the typical effects of sterols/steroids in increasing the packing density and thermal stability of fluid lipid bilayers are optimal when an OH group rather than C=O group is present at C3, and that this OH group is more effective in the equatorial rather than the axial orientation. We can explain all of our sterol results by noting that the shift of the double bond from Δ(5) to Δ(4) introduces of a bend in ring A, which in turn destroys the coplanarity of the steroid fused ring system and reduces the goodness of sterol packing in the host DPPC bilayer. However, this conformational change should also occur in the ketosteroid pair, yet our experimental results indicate that the presence of the Δ(4) double bond is less disruptive than a double bond at Δ(5). We suggest that the presence of keto-enol tautomerism in the conjugated Δ(4) ketosteroid, but not in the nonconjugated Δ(5) compound, may provide additional H-bonding opportunities to adjacent DPPC molecules in the bilayer, which can overcome the unfavourable conformational change in ring A induced by the Δ(4) double bond. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Chemical characteristics of dicarboxylic acids and related organic compounds in PM2.5 during biomass-burning and non-biomass-burning seasons at a rural site of Northeast China.

PubMed

Cao, Fang; Zhang, Shi-Chun; Kawamura, Kimitaka; Liu, Xiaoyan; Yang, Chi; Xu, Zufei; Fan, Meiyi; Zhang, Wenqi; Bao, Mengying; Chang, Yunhua; Song, Wenhuai; Liu, Shoudong; Lee, Xuhui; Li, Jun; Zhang, Gan; Zhang, Yan-Lin

2017-12-01

Fine particulate matter (PM2.5) samples were collected using a high-volume air sampler and pre-combusted quartz filters during May 2013 to January 2014 at a background rural site (47 ∘ 35 N, 133 ∘ 31 E) in Sanjiang Plain, Northeast China. A homologous series of dicarboxylic acids (C 2 -C 11 ) and related compounds (oxoacids, α-dicarbonyls and fatty acids) were analyzed by using a gas chromatography (GC) and GC-MS method employing a dibutyl ester derivatization technique. Intensively open biomass-burning (BB) episodes during the harvest season in fall were characterized by high mass concentrations of PM2.5, dicarboxylic acids and levoglucosan. During the BB period, mass concentrations of dicarboxylic acids and related compounds were increased by up to >20 times with different factors for different organic compounds (i.e., succinic (C 4 ) acid > oxalic (C 2 ) acid > malonic (C 3 ) acid). High concentrations were also found for their possible precursors such as glyoxylic acid (ωC 2 ), 4-oxobutanoic acid, pyruvic acid, glyoxal, and methylglyoxal as well as fatty acids. Levoglucosan showed strong correlations with carbonaceous aerosols (OC, EC, WSOC) and dicarboxylic acids although such good correlations were not observed during non-biomass-burning seasons. Our results clearly demonstrate biomass burning emissions are very important contributors to dicarboxylic acids and related compounds. The selected ratios (e.g., C 3 /C 4 , maleic acid/fumaric acid, C 2 /ωC 2 , and C 2 /levoglucosan) were used as tracers for secondary formation of organic aerosols and their aging process. Our results indicate that organic aerosols from biomass burning in this study are fresh without substantial aging or secondary production. The present chemical characteristics of organic compounds in biomass-burning emissions are very important for better understanding the impacts of biomass burning on the atmosphere aerosols. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis, structure, optical, photoluminescence and magnetic properties of K2[Co(C2O4)2(H2O)2]·4H2O

NASA Astrophysics Data System (ADS)

Narsimhulu, M.; Hussain, K. A.

2018-06-01

The synthesis, crystal structure, optical, photoluminescence and magnetic behaviour of potassium bis(oxalato)cobaltate(II)tertrahydrate{K2[Co(C2O4)2(H2O)2]·4H2O} are described. The compound was grown at room temperature from mixture of aqueous solutions by slow evaporation method. The X-ray crystallographic data showed that the compound belongs to the monoclinic crystal system with P21/n space group and Z = 4. The UV-visible diffuse absorbance spectra exhibited bands at 253, 285 and 541 nm in the visible and ultraviolet regions. The optical band gap of the compound was estimated as 3.4 eV. At room temperature, an intense photoluminescence was observed from this material around 392 nm when it excited at 254 nm. The variable temperature dc magnetic susceptibility measurements exposed paramagnetic behaviour at high temperatures and antiferromagnetic ordering at low temperatures.

Syntheses, crystal structures and Raman spectra of Ba(BF{sub 4})(PF{sub 6}), Ba(BF{sub 4})(AsF{sub 6}) and Ba{sub 2}(BF{sub 4}){sub 2}(AsF{sub 6})(H{sub 3}F{sub 4}); the first examples of metal salts containing simultaneously tetrahedral BF{sub 4}{sup -} and octahedral AF{sub 6}{sup -} anions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lozinsek, Matic; Bunic, Tina; Goreshnik, Evgeny, E-mail: evgeny.goreshnik@ijs.s

2009-10-15

In the system BaF{sub 2}/BF{sub 3}/PF{sub 5}/anhydrous hydrogen fluoride (aHF) a compound Ba(BF{sub 4})(PF{sub 6}) was isolated and characterized by Raman spectroscopy and X-ray diffraction on the single crystal. Ba(BF{sub 4})(PF{sub 6}) crystallizes in a hexagonal P6-bar2m space group with a=10.2251(4) A, c=6.1535(4) A, V=557.17(5) A{sup 3} at 200 K, and Z=3. Both crystallographically independent Ba atoms possess coordination polyhedra in the shape of tri-capped trigonal prisms, which include F atoms from BF{sub 4}{sup -} and PF{sub 6}{sup -} anions. In the analogous system with AsF{sub 5} instead of PF{sub 5} the compound Ba(BF{sub 4})(AsF{sub 6}) was isolated and characterized.more » It crystallizes in an orthorhombic Pnma space group with a=10.415(2) A, b=6.325(3) A, c=11.8297(17) A, V=779.3(4) A{sup 3} at 200 K, and Z=4. The coordination around Ba atom is in the shape of slightly distorted tri-capped trigonal prism which includes five F atoms from AsF{sub 6}{sup -} and four F atoms from BF{sub 4}{sup -} anions. When the system BaF{sub 2}/BF{sub 3}/AsF{sub 5}/aHF is made basic with an extra addition of BaF{sub 2}, the compound Ba{sub 2}(BF{sub 4}){sub 2}(AsF{sub 6})(H{sub 3}F{sub 4}) was obtained. It crystallizes in a hexagonal P6{sub 3}/mmc space group with a=6.8709(9) A, c=17.327(8) A, V=708.4(4) A{sup 3} at 200 K, and Z=2. The barium environment in the shape of tetra-capped distorted trigonal prism involves 10 F atoms from four BF{sub 4}{sup -}, three AsF{sub 6}{sup -} and three H{sub 3}F{sub 4}{sup -} anions. All F atoms, except the central atom in H{sub 3}F{sub 4} moiety, act as mu{sub 2}-bridges yielding a complex 3-D structural network. - Graphical abstract: The first three compounds, containing simultaneously tetrahedral BF{sub 4}{sup -} and octahedral AF{sub 6}{sup -} (A=P, As) anions have been synthesized and characterized by Raman spectroscopy and X-ray single crystal diffraction. In the system BaF{sub 2}/BF{sub 3}/PF{sub 5}/anhydrous hydrogen fluoride (aHF) the compound Ba(BF{sub 4})(PF{sub 6}) was isolated. In the analogous system with AsF{sub 5} instead of PF{sub 5} the compound Ba(BF{sub 4})(AsF{sub 6}) was obtained. When the system BaF{sub 2}/BF{sub 3}/AsF{sub 5}/aHF is made basic with an extra addition of BaF{sub 2}, the compound Ba{sub 2}(BF{sub 4}){sub 2}(AsF{sub 6})(H{sub 3}F{sub 4}) was prepared.« less

Monitoring the biodegradability of bisphenol A and its metabolic intermediates by manometric respirometry tests.

PubMed

Ferro Orozco, A M; Contreras, E M; Zaritzky, N E

2016-11-01

As a result of its wide usage in the production of polycarbonate plastics and epoxy resins, bisphenol A (BPA) is commonly detected in wastewaters. Recently, BPA became a major concern because its adverse effects as an endocrine disruptor. In this work, the biodegradation kinetics of BPA and its metabolic intermediates 4-hydroxyacetophenone (4HAP), 4-hydroxybenzaldehyde (4HB) and 4-hydroxybenzoic acid (4HBA) by BPA-acclimated activated sludge was studied using manometric respirometry (BOD) tests. For all the tested compounds, BOD curves exhibited two phases. In the first one, a fast increase of the oxygen consumption (OC) due to the active oxidation of the substrate was obtained. Then, when the substrate was exhausted, the endogenous respiration produced a slower increase of OC. A standard Monod-model with biomass growth was used to represent the OC profiles as a function of time. For all the tested compounds, a good agreement between the proposed model and the experimental data was obtained. According to their biodegradation rates, the tested compounds can be ordered as follows: BPA < 4HAP ≪ 4HB < 4HBA. Because the oxidation rate of BPA by BPA-acclimated activated sludge limits the rate of the whole biodegradation pathway, the accumulation of metabolic intermediates 4HAP, 4HB, and 4HBA would be negligible. To calculate the dissolved oxygen (DO) concentration (C) during the BOD tests, the oxygen transfer coefficient (k L a) of the BOD bottles was obtained using the sulfite method. Finally, a simple procedure to calculate the minimum DO concentration (C min ) based on BOD data was developed. Calculation results demonstrated that under the tested conditions, C values were high enough as not to be the limiting substrate for the microbial growth.

Synthesis and characterization of a cadmium(II)-organic supramolecular coordination compound based on the multifunctional 2-amino-5-sulfobenzoic acid ligand.

PubMed

Yuan, Gan Yin; Zhang, Lei; Wang, Meng Jie; Zhang, Kou Lin

2016-12-01

Much attention has been paid by chemists to the construction of supramolecular coordination compounds based on the multifunctional ligand 5-sulfosalicylic acid (H 3 SSA) due to the structural and biological interest of these compounds. However, no coordination compounds have been reported for the multifunctional amino-substituted sulfobenzoate ligand 2-amino-5-sulfobenzoic acid (H 2 asba). We expected that H 2 asba could be a suitable building block for the assembly of supramolecular networks due to its interesting structural characteristics. The reaction of cadmium(II) nitrate with H 2 asba in the presence of the auxiliary flexible dipyridylamide ligand N,N'-bis[(pyridin-4-yl)methyl]oxamide (4bpme) under ambient conditions formed a new mixed-ligand coordination compound, namely bis(3-amino-4-carboxybenzenesulfonato-κO 1 )diaquabis{N,N'-bis[(pyridin-4-yl)methyl]oxamide-κN}cadmium(II)-N,N'-bis[(pyridin-4-yl)methyl]oxamide-water (1/1/4), [Cd(C 7 H 6 NO 5 S) 2 (C 14 H 14 N 4 O 2 ) 2 (H 2 O) 2 ]·C 14 H 14 N 4 O 2 ·4H 2 O, (1), which was characterized by single-crystal and powder X-ray diffraction analysis (PXRD), FT-IR spectroscopy, thermogravimetric analysis (TG), and UV-Vis and photoluminescence spectroscopic analyses in the solid state. The central Cd II atom in (1) occupies a special position on a centre of inversion and exhibits a slightly distorted octahedral geometry, being coordinated by two N atoms from two monodentate 4bpme ligands, four O atoms from two monodentate 4-amino-3-carboxybenzenesulfonate (Hasba - ) ligands and two coordinated water molecules. Interestingly, complex (1) further extends into a threefold polycatenated 0D→2D (0D is zero-dimensional and 2D is two-dimensional) interpenetrated supramolecular two-dimensional (4,4) layer through intermolecular hydrogen bonding. The interlayer hydrogen bonding further links adjacent threefold polycatenated two-dimensional layers into a three-dimensional network. The optical properties of complex (1) indicate that it may be used as a potential indirect band gap semiconductor material. Complex (1) exhibits an irreversible dehydration-rehydration behaviour. The fluorescence properties have also been investigated in the solid state at room temperature.

Biosynthesis of vanillin via ferulic acid in Vanilla planifolia.

PubMed

Negishi, Osamu; Sugiura, Kenji; Negishi, Yukiko

2009-11-11

(14)C-Labeled phenylalanine, 4-coumaric acid, 4-hydroxybenzaldehyde, 4-hydroxybenzyl alcohol, ferulic acid, and methionine were applied to disks of green vanilla pods 3 and 6 months after pollination (immature and mature pods), and the conversion of these compounds to vanillin or glucovanillin was investigated. In mature green vanilla pods, radioactivities of 11, 15, 29, and 24% from (14)C-labeled phenylalanine, 4-coumaric acid, ferulic acid, and methionine, respectively, were incorporated into glucovanillin within 24 h. In the incorporation processes of methionine and phenylalanine into glucovanillin, some of the (14)C labels were also trapped by the unlabeled ferulic acid. However, (14)C-labeled 4-hydroxybenzaldehyde and 4-hydroxybenzyl alcohol were not converted to glucovanillin. On the other hand, in immature green vanilla pods radioactivities of the above six compounds were not incorporated into glucovanillin. Although 4-coumaric acid, ferulic acid, 4-hydroxybenzaldehyde, and 4-hydroxybenzyl alcohol were converted to the respective glucose esters or glucosides and vanillin was converted to glucovanillin, their conversions were believed to be from the detoxication of the aglycones. These results suggest that the biosynthetic pathway for vanillin is 4-coumaric acid --> --> ferulic acid --> --> vanillin --> glucovanillin in mature vanilla pods.

Isolation of 1,4-Li(2)-C(6)H(4) and its reaction with [(Ph(3)P)AuCl].

PubMed

Flower, Kevin R; McGown, A T; Miles, Philip J; Pritchard, Robin G; Warren, John E

2010-04-14

The difficulty in generating 1,4-Li2-C6H4 utilising the lithium halogen exchange reaction on 1,4-Br2-C6H4, 1,4-I2-C6H4 and 1-Br-4-I-C6H4 is revisited and only on treatment of 1,4-I2-C6H4 with 2 molar equivalents of n-BuLi can 1,4-Li2-C6H4 1 be isolated in excellent yield. Treatment of 1 with two equivalents of [ClAu(PPh3)] gives [1,4-(Ph3PAu)2-C6H4] 2a in excellent yield. Subsequent treatment of 2a with 2.5 molar equivalents of PPh2Me, PPhMe2 or PMe3 affords the PPh3 substituted compounds [1,4-(LAu)2-C6H4] (L = PPh2Me 2b, PPhMe2 2c, PMe3 2d) in essentially quantitative yields. On treatment of 1,4-Br2-C6H4 or 1-Br-4-I-C6H4 with 2 molar equivalents of n-BuLi only mono-lithiation takes place to give 1-Br-4-Li-C6H4 3 as shown through the isolation of essentially 1:1 molar equivalents of Ph2PC6H4-4-Br and Ph2PBu on treatment with 2 molar equivalents of ClPPh2. Treatment of 3, prepared by lithium/iodine exchange on 1-Br-4-I-C6H4, with [ClAu(PPh3)] affords [(Ph3P)Au(C6H4-4-Br)] 4 as expected and in addition [(Ph3P)Au(n-Bu)(C6H4-4-Br)2] 5, indicating the straightforward chloride/aryl exchange at gold may proceed in competition with oxidative addition of the n-BuI, generated in the initial lithium/iodine exchange reaction, to some aurate complex Li[Au(C6H4-4-Br)2] 6 formed in situ followed by reductive elimination of Br-C6H4-4-n-Bu in a manner that mimics lithium diorganocuprate chemistry. All of the gold-containing compounds have been spectroscopically characterised by 1H and 31P-{1H} NMR and in addition compounds 2a-d and 5 by single crystal X-ray diffraction studies. The solid state structures observed for 2a-d are dictated by non-conventional hydrogen bonding and the packing requirements of the phosphine ligands. For 2a and 2b there is no close Au...Au approach, however for 2c and 2d the reduction in the number of phenyl rings allows the formation of Au...Au contacts. For 2c and 2d the extended structures appear to be helical chains with Au...Au contact parameters of 3.855(5) A and C-Au-Au-C 104.1(3)degrees for 2c and 3.139(4) A and C-Au-Au-C -92.0(2)degrees for 2d. The Au...Au approach in 2c is longer than is normally accepted for an AuAu contact and is dictated by ligand directed non-conventional hydrogen bonding to the aurated benzene ring and the pi-stacking requirements of the phosphine ligand. By comparison of the structures 2a-2d with other structures in the database it is evident that the aurophilic interaction is a poor supramolecular synthon in the presence of non-conventional hydrogen bond donors. Searches of the CCDC database suggest that the observed parameters for the Au...Au contact in 2c sit close to the cut-off point for observing this type of contact. In addition to aurophilic contacts and non-conventional hydrogen bonds there are a number of halogenated solvent C-Cl...Au contacts observed in the structures of 2a and 2d. The nature of these contacts have implications for the accepted van der Waals radius of gold which should be extended to 2 A.

Structural, vibrational, DFT and optical studies of a new non-centrosymmetric hybrid material (C4H12N2)[CoBr4

NASA Astrophysics Data System (ADS)

Tllili, Hafsia; Walha, Sandra; Elleuch, Slim; Fares Ali, Basem; Naïli, Houcine

2018-01-01

The crystals of the new organic-inorganic material (C4H12N2)[CoBr4] were grown by slow evaporation technique in aqueous solution and characterized by X-ray diffraction, infrared absorption, Raman spectroscopy scattering and thermal analysis. It crystallizes at room temperature in the non-centrosymmetric space group P212121. The structure is built from isolated [CoBr4]2- anions and piperazinediium (C4H12N2)2+ cations which are connected by a network of Nsbnd H⋯Br hydrogen bonds. Theoretical calculations were performed using density functional theory with the B3LYP/LanL2DZ level for studying the molecular structure and vibrational spectra of the title compound. TDDFT calculations at the same level of theory was undertaken to investigate the electronic properties. Good adhesion is observed between calculated and experimental results. The optical study reveals that the title compound undergoes three optical absorption bands at 641, 666 and 698 nm, respectively with an energy gap estimated to 2.23 eV. Based upon this value and the non-centrosymetric character of the structure, the title compound may show several interesting applications in the field of optoelectronics.

Aqueous phase synthesis, crystal structure and biological study of isoxazole extensions of pyrazole-4-carbaldehyde derivatives

NASA Astrophysics Data System (ADS)

Wazalwar, Sachin S.; Banpurkar, Anita R.; Perdih, Franc

2017-12-01

A series of novel isoxazol derivatives was synthesized by green route in aqueous phase at room temperature by the reaction of 3-methyl-4H-isoxazol-5-one with 3-(substituted phenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde by one-pot Knoevenagel condensation method using sodium benzoate as a catalyst. Compounds were characterized on the basis of IR, 1H NMR, mass spectroscopy and melting point determination. Crystal structures of five compounds were determined by X-ray diffraction. The compounds formed were screened for antibacterial and antifungal activity. Some compounds showed activity close to ampicillin against E. coli, S. aureus, and S. pyogenus. Two compounds showed antifungal activity against C. albicans close to standard greseofulvin.

A novel antibacterial and antifungal phenolic compound from the endophytic fungus Pestalotiopsis mangiferae.

PubMed

Subban, Kamalraj; Subramani, Ramesh; Johnpaul, Muthumary

2013-01-01

A novel phenolic compound, 4-(2,4,7-trioxa-bicyclo[4.1.0]heptan-3-yl) phenol (1), was isolated from Pestalotiopsis mangiferae, an endophytic fungus associated with Mangifera indica Linn. The structure of the compound was elucidated on the basis of comprehensive spectral analysis (UV, IR, ¹H-, ¹³C- and 2D-NMR, as well as HRESI-MS). Compound (1) shows potent antibacterial and antifungal activity against Bacillus subtilis, Klebsiella pneumoniae, Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa and Candida albicans. The transmission electron microscope study for the mode of inhibition of compound (1) on bacterial pathogens revealed the destruction of bacterial cells by cytoplasm agglutination with the formation of pores in cell wall membranes.

Antifungal Compound Isolated from Catharanthus roseus L. (Pink) for Biological Control of Root Rot Rubber Diseases.

PubMed

Zahari, R; Halimoon, N; Ahmad, M F; Ling, S K

2018-01-01

Rigidoporus microporus, Ganoderma philippii, and Phellinus noxius are root rot rubber diseases and these fungi should be kept under control with environmentally safe compounds from the plant sources. Thus, an antifungal compound isolated from Catharanthus roseus was screened for its effectiveness in controlling the growth of these fungi. The antifungal compound isolated from C. roseus extract was determined through thin layer chromatography (TLC) and nuclear magnetic resonance (NMR) analysis. Each C. roseus of the DCM extracts was marked as CRD1, CRD2, CRD3, CRD4, CRD5, CRD6, and CRD7, respectively. TLC results showed that all of the C. roseus extracts peaked with red colour at Rf = 0.61 at 366 nm wavelength, except for CRD7. The CRD4 extract was found to be the most effective against R. microporus and G. philippii with inhibition zones of 3.5 and 1.9 mm, respectively, compared to that of other extracts. These extracts, however, were not effective against P. noxius. The CRD4 extract contained ursolic acid that was detected by NMR analysis and the compound could be developed as a biocontrol agent for controlling R. microporus and G. philippii. Moreover, little or no research has been done to study the effectiveness of C. roseus in controlling these fungi.

Laser photolysis studies of ω-bond dissociation in aromatic carbonyls with a C-C triple bond stimulated by triplet sensitization.

PubMed

Yamaji, Minoru; Horimoto, Ami; Marciniak, Bronislaw

2017-07-14

We have prepared three types of carbonyl compounds, benzoylethynylmethyl phenyl sulfide (2@SPh), (p-benzoyl)phenylethynylmethyl phenyl sulfide (3@SPh) and p-(benzoylethynyl)benzyl phenyl sulfide (4@SPh) with benzoyl and phenylthiylmethyl groups, which are interconnected with a C-C triple bond and a phenyl ring. Laser flash photolysis of 3@SPh and 4@SPh in acetonitrile provided the transient absorption spectra of the corresponding triplet states where no chemical reactions were recognized. Upon laser flash photolysis of 2@SPh, the absorption band due to the phenylthiyl radical (PTR) was obtained, indicating that the C-S bond cleaved in the excited state. Triplet sensitization of these carbonyl compounds using acetone and xanthone was conducted using laser photolysis techniques. The formation of triplet 3@SPh was seen in the transient absorption, whereas the PTR formation was observed for 2@SPh and 4@SPh, indicating that the triplet states were reactive for the C-S bond dissociation. The C-S bond dissociation mechanism for 4@SPh upon triplet sensitization is discussed in comparison with those for 2@SPh and 3@SPh.

Synthesis and characterization of SiC based composite materials for immobilizing radioactive graphite

NASA Astrophysics Data System (ADS)

Wang, Qing; Teng, Yuancheng; Wu, Lang; Zhang, Kuibao; Zhao, Xiaofeng; Hu, Zhuang

2018-06-01

In order to immobilize high-level radioactive graphite, silicon carbide based composite materials{ (1-x) SiC· x MgAl2O4 (0.1 ≤ x≤0.4) } were fabricated by solid-state reaction at 1370 °C for 2 h in vacuum. Residual graphite and precipitated corundum were observed in the as-synthesized product, which attributed to the interface reaction of element silicon and magnesium compounds. To further understand the reasons for the presence of graphite and corundum, the effects of mole ratio of Si/C, MgAl2O4 content and non-stoichiometry of MgAl2O4 on the synthesis were investigated. To immobilize graphite better, residual graphite should be eliminated. The target product was obtained when the mole ratio of Si/C was 1.3:1, MgAl2O4 content was x = 0.2, and the mole ratio of Al to Mg in non-stoichiometric MgAl2O4 was 1.7:1. In addition, the interface reaction between magnesium compounds and silicon not graphite was displayed by conducting a series of comparative experiments. The key factor for the occurrence of interface reaction is that oxygen atom is transferred from magnesium compound to SiO gas. Infrared and Raman spectrum revealed the increased disorders of graphite after being synthesized.

Synthesis, crystal structure, DFT studies, acid dissociation constant, and antimicrobial activity of methyl 2-(4-chlorophenyl)-7a-((4-chlorophenyl)carbamothioyl)-1-oxo-5,5-diphenyl-3-thioxo-hexahydro-1H-pyrrolo[1,2-e]imidazole-6-carboxylate

NASA Astrophysics Data System (ADS)

Nural, Yahya; Gemili, Muge; Seferoglu, Nurgul; Sahin, Ertan; Ulger, Mahmut; Sari, Hayati

2018-05-01

A novel bicyclic thiohydantoin fused to pyrrolidine compound, methyl 2-(4-chlorophenyl)-7a-((4-chlorophenyl)carbamothioyl)-1-oxo-5,5-diphenyl-3-thioxo-hexahydro-1H-pyrrolo[1,2-e]imidazole-6-carboxylate, was synthesized by the cyclization reaction of dimethyl 5,5-diphenylpyrrolidine-2,4-dicarboxylate and 4-chlorophenyl isothiocyanate in the presence of 4-(dimethylamino)pyridine to form methyl 2-(4-chlorophenyl)-1-oxo-5,5-diphenyl-3-thioxo-hexahydro-1H-pyrrolo[1,2-e]imidazole-6-carboxylate with concomitant addition reaction of the 4-chlorophenyl isothiocyanate in 79% yield. The structural characterization was performed by NMR, FT-IR, MS and HRMS techniques, and the stereochemistry of the compound was determined by single crystal X-ray diffraction study. In addition, the molecular structure and 1H and 13C NMR chemical shifts of the compound were obtained with the density functional theory and Hartree-Fock calculations. Acid dissociation constants of the compound were determined using potentiometric titration method in 25% (v/v) dimethyl sulfoxide-water hydroorganic solvent at 25 ± 0.1 °C, at an ionic background of 0.1 mol/L of NaCl using the HYPERQUAD computer program. Four acid dissociation constants were obtained for the compound, and we suggest that these acid dissociation constants are related to the NH, for two groups of enthiols and enol groups. Antimicrobial activity study was performed against S. aureus, B. subtilis, A. hydrophila, E. coli and A. baumannii as bacterial standard strains, and against M. tuberculosis H37Rv as mycobacterial strain. The compound exhibited antibacterial activity in the range of 31.25-62.5 μg/mL, and antimycobacterial activity with a MIC value of 40 μg/mL against the indicated strains.

Synthesis of New Thiazolyl Coupled Pyrazoles Bearing 2,4-Thiazolidinedionyl Pharmacophore and Their Anti-Inflammatory and Antibacterial Evaluation.

PubMed

Khillare, Lalit; Bhosle, Manisha; Bhalerao, Mahendra; Kharat, Kiran; Mane, Ramrao

2017-01-01

2, 4-Thiazolidinedione (TZD), pyrazole and thiazole heterocyclic rings exhibit a wide range of pharmacological activities. Medicinal chemists use these heterocyclic moieties as scaffolds in drug designing and discovery. The existing medicaments, celecoxib and meloxicam, used for treating inflammation and pain are having, pyrazole and thiazole, respectively as key scaffolds. Pyrazoles coupled with 2, 4-thiazolidinediones may display enhanced anti-inflammatory activity. With this hope the bench work was carried out. Heterocyclic aldehydes, 3-(4-methyl-2-substituted thiazol-5-yl)-1-phenyl-1Hpyrazole- 4- carbaldehydes (4a-b) have been allowed to undergo Knoevenagel condensation with N-substituted 2,4-thiazolidinediones (5a-e) in PEG-400 in the presence of L-proline at 110°C and obtained the condensed products (6a-j). COX-2 evaluation of the titled product has been carried out using in vitro COX-2 ELISA Kit. Antibacterial activity of these compounds (6a-j) has also been determined. On the basis of 1H NMR, 13C NMR and Mass spectral data of the condensed products the structures have been assigned to (Z)-5-((3-(4-methyl-2-substituted thiazol-5-yl)-1- phenyl-1H-pyrazol-4-yl)methylene) 3-substituted thiazolidine-2,4-diones (6a-j). Among the evaluated compounds (6a-j), 6f, 6g, 6h, 6i and 6j have shown notable COX-2 inhibitory activity. Compounds, 6a, 6b, 6c, 6d, 6e and 6f have inhibited the growth of the Bacillus cereus NCIM 2106, Bacillus subtilis NCIM 2063, Pseudomonas aeruginosa NCIM 2074, Salmonella typhimurium NCIM 2501 and Staphylococcus aureus NCIM 2079. However, compound 6f has emerged as a suitable candidate with dual properties i.e. COX-2 inhibitory and antibacterial in the present study. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

New chalcone and dimeric chalcones with 1,4-p-benzoquinone residue from Combretum yunnanense.

PubMed

Wu, Ming-Mei; Wang, Li-Qin; Hua, Yan; Chen, Ye-Gao; Wang, Yuan-Yuan; Li, Xing-Yao; Li, Yan; Li, Ting; Yang, Xun-Yun; Tang, Zheng-Rong

2011-03-01

New chalcone and dimeric chalcones with 1,4- P-benzoquinone residue, combrequinone A (1), combrequinone B (2), and combrequinone C (3), along with three known compounds (4-6), were isolated from the ethanolic extract of the stems and leaves of Combretum yunnanense, and their structures were determined by spectroscopic analysis. Compounds 1-3 were evaluated for in vitro cytotoxicity against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7, and SW480. Compounds 1, 2 and 3 were found to be most potent against HL-60 acute leukemia cells, with IC₅₀ values of 4.63, 4.07, and 1.26 µM, respectively. © Georg Thieme Verlag KG Stuttgart · New York.

Structural variability in neptunium(V) oxalate compounds: synthesis and structural characterization of Na2NpO2(C2O4)OH.H2O.

PubMed

Bean, Amanda C; Garcia, Eduardo; Scott, Brian L; Runde, Wolfgang

2004-10-04

Reaction of a (237)Np(V) stock solution in the presence of oxalic acid, calcium chloride, and sodium hydroxide under hydrothermal conditions produces single crystals of a neptunium(V) oxalate, Na(2)NpO(2)(C(2)O(4))OH.H(2)O. The structure consists of one-dimensional chains running down the a axis and is the first example of a neptunium(V) oxalate compound containing hydroxide anions.

Mono- and dinuclear tetraphosphabutadiene ferrate anions.

PubMed

Chakraborty, Uttam; Leitl, Julia; Mühldorf, Bernd; Bodensteiner, Michael; Pelties, Stefan; Wolf, Robert

2018-03-12

Reduction of [Cp Ar Fe(μ-Br)] 2 (1, Cp Ar = C 5 (C 6 H 4 -4-Et) 5 ) by potassium napthalenide, followed by the addition of white phosphorus, affords [K(18-c-6){Cp Ar Fe(η 4 -P 4 )}] (2, 18-c-6 = [18]crown-6), which features a planar cyclo-P 4 2- ligand. The related diiron complex [Na 2 (THF) 5 (Cp Ar Fe) 2 (μ,η 4:4 -P 4 )] (3) was obtained by reducing 1 with sodium amalgam in the presence of P 4 . Protonation of 3 affords [Na(THF) 3 ][(Cp Ar Fe) 2 (μ,η 4:4 -P 4 )(H)] (4), while the reaction of 3 with trimethylchlorosilane gives the nortricyclane compound P 7 (SiMe 3 ) 3 as the main product.

Identification and bioactivity of compounds from the fungus Penicillium sp. CYE-87 isolated from a marine tunicate.

PubMed

Shaala, Lamiaa A; Youssef, Diaa T A

2015-03-25

In the course of our continuous interest in identifying bioactive compounds from marine microbes, we have investigated a tunicate-derived fungus, Penicillium sp. CYE-87. A new compound with the 1,4-diazepane skeleton, terretrione D (2), together with the known compounds, methyl-2-([2-(1H-indol-3-yl)ethyl]carbamoyl)acetate (1), tryptamine (3), indole-3-carbaldehyde (4), 3,6-diisobutylpyrazin-2(1H)-one (5) and terretrione C (6), were isolated from Penicillium sp. CYE-87. The structures of the isolated compounds were established by spectral analysis, including 1D (1H, 13C) and 2D (COSY, multiplicity edited-HSQC and HMBC) NMR and HRESIMS, as well as comparison of their NMR data with those in the literature. The compounds were evaluated for their antimigratory activity against the human breast cancer cell line (MDA-MB-231) and their antiproliferation activity against HeLa cells. Compounds 2 and 6 showed significant antimigratory activity against MDA-MB-231, as well as antifungal activity against C. albicans.

Identification and Bioactivity of Compounds from the Fungus Penicillium sp. CYE-87 Isolated from a Marine Tunicate

PubMed Central

Shaala, Lamiaa A.; Youssef, Diaa T. A.

2015-01-01

In the course of our continuous interest in identifying bioactive compounds from marine microbes, we have investigated a tunicate-derived fungus, Penicillium sp. CYE-87. A new compound with the 1,4-diazepane skeleton, terretrione D (2), together with the known compounds, methyl-2-([2-(1H-indol-3-yl)ethyl]carbamoyl)acetate (1), tryptamine (3), indole-3-carbaldehyde (4), 3,6-diisobutylpyrazin-2(1H)-one (5) and terretrione C (6), were isolated from Penicillium sp. CYE-87. The structures of the isolated compounds were established by spectral analysis, including 1D (1H, 13C) and 2D (COSY, multiplicity edited-HSQC and HMBC) NMR and HRESIMS, as well as comparison of their NMR data with those in the literature. The compounds were evaluated for their antimigratory activity against the human breast cancer cell line (MDA-MB-231) and their antiproliferation activity against HeLa cells. Compounds 2 and 6 showed significant antimigratory activity against MDA-MB-231, as well as antifungal activity against C. albicans. PMID:25815893

Crosslinking and degradation mechanisms in model sealant candidates

NASA Technical Reports Server (NTRS)

Paciorek, K. L.; Kaufman, J.; Kratzer, R. H.

1974-01-01

Heterocyclic ring systems were investigated, triazines and 1,2,4-oxadiazoles. Only a limited effort was extended to the preparation of triazoles. Compounds, n-perfluoroheptyl-s-triazine, a perfluoroether substituted triazine, C3F7OCF(CF3)CF2OCF(CF3) 3C3N3,1,4-bus (5-perfluoro-n-heptyl)-1,2,4-oxadiazolyl -benzene, its perfluoroalkylether substituded analogue, and 3,5-bis(perfluoro-n-heptyl)-1,2,4-oxadiazole were synthesized and characterized. To eliminate the effect due to a tertiary fluorine present in branched materials, the pure n-alkyl-compounds were prepared. The main starting material, perfluoro-n-octanonitrile, was obtained from commercially available perfluoro-n-octanoic acid via a three step synthesis.

Ionothermal synthesis of open-framework metal phosphates with a Kagomé lattice network exhibiting canted anti-ferromagnetism† †Electronic supplementary information (ESI) available: Cif files, atomic parameters, X-ray diffraction patterns, IR spectra, TG curves, and thermal ellipsoid plot and atomic label schemes of compound 1–4. See DOI: 10.1039/c4tc00290c Click here for additional data file.

PubMed Central

Wang, Guangmei; Valldor, Martin; Mallick, Bert

2014-01-01

Four open-framework transition-metal phosphates; (NH4)2Co3(HPO4)2F4 (1), (NH4)Co3(HPO4)2(H2PO4)F2 (2), KCo3(HPO4)2(H2PO4)F2 (3), and KFe3(HPO4)2(H2PO4)F2 (4); are prepared by ionothermal synthesis using pyridinium hexafluorophosphate as the ionic liquid. Single-crystal X-ray diffraction analyses reveal that the four compounds contain cobalt/iron–oxygen/fluoride layers with Kagomé topology composed of interlinked face-sharing MO3F3/MO4F2 octahedra. PO3OH pseudo-tetrahedral groups augment the [M3O6F4] (1)/[M3O8F2] layers on both sides to give M3(HPO4)2F4 (1) and M3(HPO4)2F2 (2–4) layers. These layers are stacked along the a axis in a sequence AA…, resulting in the formation of a layer structure for (NH4)2Co3(HPO4)2F4(1). In NH4Co3(HPO4)2(H2PO4)F2 and KM3(HPO4)2(H2PO4)F2, the M3(HPO4)2F2 layers are stacked along the a axis in a sequence AAi… and are connected by [PO3(OH)] tetrahedra, giving rise to a 3-D open framework structure with 10-ring channels along the [001] direction. The negative charges of the inorganic framework are balanced by K+/NH4 + ions located within the channels. The magnetic transition metal cations themselves form layers with stair-case Kagomé topology. Magnetic susceptibility and magnetization measurements reveal that all four compounds exhibit a canted anti-ferromagnetic ground state (T c = 10 or 13 K for Co and T c = 27 K for Fe) with different canting angles. The full orbital moment is observed for both Co2+ and Fe2+. PMID:25580250

Preparation of perfluorinated 1,2,4-oxadiazoles

NASA Technical Reports Server (NTRS)

Kratzer, R. H.; Paciorek, K. J. L.; Ito, T. I.; Rosser, R. W. (Inventor)

1982-01-01

Fluorinated alkyl or alkylether 1,2,4 oxadiazole compounds are prepared by cyclizing the corresponding alkyl or alkylether imidoyl amidoximes in vacuo or in an inert atmosphere at a temperature within the range of 40 C to 100 C. for a period of 8 to 144 hours in the presence of an acid compound which can accept ammonia to form a salt. The imidoyl amidoximes usable in this process are either polymeric or nonpolymeric. The products, when polymeric, have excellent heat, chemical and solvent resistance.

Lactone Derivatives Produced by a Phaeoacremonium sp., an Endophytic Fungus from Senna spectabilis.

PubMed

Silva, Geraldo H; Zeraik, Maria L; de Oliveira, Camila M; Teles, Helder L; Trevisan, Henrique C; Pfenning, Ludwig H; Nicolli, Camila P; Young, Maria C M; Mascarenhas, Yvonne P; Abreu, Lucas M; Saraiva, Amanda C; Medeiros, Alexandra I; Bolzani, Vanderlan da S; Araujo, Angela R

2017-05-26

Three new isoaigialones, A, B, and C (1-3), along with aigialone (4), were isolated from the crude EtOAc extract of a Phaeoacremonium sp., an endophytic fungus obtained from the leaves of Senna spectabilis. The structures of these compounds were elucidated based on the analysis of spectroscopic data. Compounds 2 and 4 were active against the phytopathogenic fungi Cladosporium cladosporioides and C. sphaerospermum. This is the first report of metabolites produced by an Phaeoacremonium sp., associated with S. spectabilis.

Synthesis and anti-HIV activity of novel 3-substituted phenyl-6,7-dimethoxy-3a,4-dihydro-3H-indeno[1,2-c]isoxazole analogues.

PubMed

Ali, Mohamed A; Ismail, Rusli; Choon, Tan S; Yoon, Yeong K; Wei, Ang C; Pandian, Suresh; Samy, Jeyabalan G; De Clercq, Eric; Pannecouque, Christophe

2011-01-01

A series of novel 3-(substituted phenyl)-6,7-dimethoxy-3a,4-dihydro-3H-indeno[1,2-c]isoxazole analogues were synthesized by the reaction of 5,6-dimethoxy-2-[(E)-1-phenylmethylidene]-1-indanone with hydroxylamine hydrochloride. The title compounds were tested for their in vitro anti-HIV activity. Among the compounds, (4g) showed a promising anti-HIV activity in the in vitro testing against IIIB and ROD strains. The IC50 of both IIIB and ROD were found to be 9.05 microM and > 125 microM, respectively.

Magnetic structure of DyFe3

NASA Astrophysics Data System (ADS)

Jin, Long-huan; W, J. James; J, Rhyne; R, Lemaire

1985-06-01

Powder neutron diffraction measurements have been carried out on the intermetallic compound DyFe3 at 4 and 295K. The magnetic structure of the compound at 4 and 295K are noncollinear but coplanar in the a-c plane, and the moments of the Dy and Fe ions lie closer to the basal plane.

Influence of the synthetic conditions on the structural diversity of extended manganese-oxalato-1,2-bis(4-pyridyl)ethylene systems.

PubMed

García-Couceiro, Urko; Castillo, Oscar; Cepeda, Javier; Lanchas, Mónica; Luque, Antonio; Pérez-Yáñez, Sonia; Román, Pascual; Vallejo-Sánchez, Daniel

2010-12-20

We report herein the synthesis and physicochemical characterization of eight new manganese-oxalato compounds with 1,2-bis(4-pyridyl)ethylene (bpe): {(Hbpe)(2)[Mn(2)(μ-ox)(3)]·∼0.8(C(2)H(5)OH)·∼0.4(H(2)O)}(n) (1), {[Mn(μ-ox)(μ-bpe)]·xH(2)O}(n) (2), [Mn(2)(μ-ox)(2)(μ-bpe)(bpe)(2)](n) (3), [Mn(μ-ox)(μ-bpe)](n) (4a and 4b), and {[Mn(4)(μ-ox)(3)(μ-bpe)(4)(H(2)O)(4)]·(X)(2)·mY}(n) with X = NO(3)(-) (5a), Br(-) (5b), and ClO(4)(-) (5c) and Y = solvation molecules. The appropriate selection of the synthetic conditions allowed us to control the crystal structure and to design extended 2D and 3D frameworks. Compound 1 is obtained at acid pH values and its crystal structure consists of stacked [Mn(2)(μ-ox)(3)](2-) layers with cationic Hbpe(+) molecules intercalated among them. Compound 2 was obtained at basic pH values with a manganese/bpe ratio of 1:1, and the resulting 3D structure consists of an interpenetrating framework in which metal-oxalato chains are bridged by bpe ligands, leading to a microporous network that hosts a variable number of water molecules (between 0 and 1) depending on the synthetic conditions. Compound 3, synthesized with a manganese/bpe ratio of 1:3, shows a 2D framework in which linear metal-oxalato chains are joined by bis-monodentate 1,2-bis(4-pyridyl)ethylene ligands. The thermal treatment of compound 3 permits the release of one of the bpe molecules, giving rise to two new 2D crystalline phases of formula [Mn(μ-ox)(μ-bpe)](n) (4a and 4b) depending on the heating rate. The open structures of 5a-5c were synthesized in a medium with a high concentration of nitrate, perchlorate, or bromide salts (potassium or sodium as cations). These anions behave as templating agents directing the crystal growing toward a cationic porous network, in which the anions placed in the voids and channels of the structure present high mobility, as inferred from the ionic exchange experiments. Variable-temperature magnetic susceptibility measurements show an overall antiferromagnetic behavior for all compounds, which are discussed in detail.

The crystal structures of six (2E)-3-aryl-1-(5-halogeno­thio­phen-2-yl)prop-2-en-1-ones

PubMed Central

Naik, Vasant S.; Yathirajan, Hemmige S.; Jasinski, Jerry P.; Smolenski, Victoria A.; Glidewell, Christopher

2015-01-01

The structures of six chalcones containing 5-halogeno­thio­phen-2-yl substituents are reported: (2E)-1-(5-chloro­thio­phen-2-yl)-3-(4-ethyl­phen­yl)prop-2-en-1-one, C15H13ClOS, (I), and (2E)-1-(5-bromo­thio­phen-2-yl)-3-(4-ethyl­phen­yl)prop-2-en-1-one, C15H13BrOS, (II), are isostructural in space group P-1, while (2E)-1-(5-chloro­thio­phen-2-yl)-3-(4-eth­oxy­phen­yl)prop-2-en-1-one, C15H13ClO2S, (III), and (2E)-1-(5-bromo­thio­phen-2-yl)-3-(4-eth­oxy­phen­yl)prop-2-en-1-one C15H13BrO2S, (IV), are isostructural in space group P21/c. There are no hydrogen bonds of any kind in the structures of compounds (I) and (II), but in the structures of compounds (III) and (IV), the mol­ecules are linked into C(7) chains by means of C—H⋯O hydrogen bonds. In the structure of (2E)-3-(4-bromo­phen­yl)-1-(5-chloro­thio­phen-2-yl)prop-2-en-1-one, C13H8BrClOS, (V), there are again no hydrogen bonds nor π–π stacking inter­actions but in that of (2E)-1-(5-bromo­thio­phen-2-yl)-3-(3-meth­oxy­phen­yl)prop-2-en-1-one, C14H11BrO2S, (VI), the mol­ecules are linked into C(5) chains by C—H⋯O hydrogen bonds. In each of compounds (I)–(VI), the mol­ecular skeletons are close to planarity, and there are short halogen⋯halogen contacts in the structures of compounds (II) and (V) and a short Br⋯O contact in the structure of compound (VI). Comparisons are made with the structures of some similar compounds. PMID:26396857

Synthesis and Characterization of Polyether Adducts of Barium and Strontium Carboxylates and Their Use in the Formation of MTiO(3) Films.

PubMed

Wojtczak, William A.; Atanassova, Paolina; Hampden-Smith, Mark J.; Duesler, Eileen

1996-11-20

The synthesis, characterization, and reactivity of new polyether adducts of strontium and barium carboxylates of general composition M(O(2)CCF(3))(n)()(L) (M = Ba, L = 15-crown-5, (1); M = Ba (2), Sr (3), respectively, with L = tetraglyme are reported. The compounds were synthesized by reaction of BaCO(3) or MH(2) (M = Sr or Ba) with organic acids in the presence of the polyether ligands. These compounds have been characterized by IR and (13)C and (1)H NMR spectroscopies, elemental analyses, and thermogravimetric analysis. The species Ba(2)(O(2)CCF(3))(4)(15-crown-5)(2) (1) and [Ba(2)(O(2)CCF(3))(4)(tetraglyme)](infinity) (2), were also characterized by single-crystal X-ray diffraction. Ba(2)(O(2)CCF(3))(4)(15-crown-5)(2) (1) crystallizes in the orthorhombic space group Cccm with cell dimensions of a = 13.949(1) Å, b = 19.376(2) Å, c = 16.029(1) Å, and Z = 8. [Ba(2)(O(2)CCF(3))(4)(tetraglyme)](infinity) (2) crystallizes in the monoclinic space group C2/c with cell dimensions of a = 12.8673(12) Å, b = 16.6981(13) Å, c = 15.1191(12) Å, beta = 99.049(8) degrees, and Z = 4. Compounds 1-3 thermally decompose at high temperatures in the solid state to give MF(2). However, solutions of compounds 1-3 dissolved in ethanol with Ti(O-i-Pr)(4) give crystalline perovskite phase MTiO(3) films, or in the case of mixtures of 2 and 3, Ba(1)(-)(x)()Sr(x)()TiO(3) films below 600 degrees C when spin coated onto silicon substrates and thermally treated. The crystallinity, purity, and elemental composition of the films was determined by glancing angle X-ray diffraction and Auger electron spectroscopy.

Search for Sugars and Related Compounds in Residues Produced from the UV Irradiation of Astrophysical Ice Analogs

NASA Technical Reports Server (NTRS)

Sandford, S. A.; Nuevo, M.; Materese, C. K.; Cooper, G. W.

2015-01-01

A large variety of organics of biological and prebiotic interests have been detected in meteorites, including one sugar and several sugar acids and sugar alcohols [1]. The presence of these compounds in meteorites, along with amino acids, amphiphiles, and nucleobases [2-4], indicates that molecules essential to life can be formed abiotically under astrophysical conditions. This hypothesis is supported by extensive laboratory studies involving the formation of complex organic molecules from the ultraviolet (UV) irradiation of astrophysical ice analogs (H2O, CO, CO2, CH3OH, CH4, NH3, etc.). These studies show that the organic residues recovered at room temperature contain many of the same compounds as those found in meteorites[3,58]. However, to the best of our knowledge, no systematic search for the presence of sugars and sugar derivatives in such laboratory residues have been reported to date. Only a limited number of small (greater than 4 C atoms) sugar-related compounds such as glycerol and glyceric acid [9], and more recently small (2-4 C atoms) aldehydes [10] have been detected in residues.

Synthesis, structure and characterization of two new organic template-directed gallium phosphate/phosphite-oxalates

NASA Astrophysics Data System (ADS)

Xue, Zhen-Zhen; Pan, Jie; Li, Jin-Hua; Wang, Zong-Hua; Wang, Guo-Ming

2017-06-01

Two new gallium phosphate/phosphite-oxalates hybrid solids, {[H2dmpip][Ga2(HPO4)2(PO4)(C2O4)0.5]·H2O} (1) and [H2apm][Ga2(H2PO3)2(HPO3)2(C2O4)] (2), where dmpip = 2,6-dimethyl-piperazine and apm = N-(3-aminopropyl)morpholine, have been synthesized and structurally characterized. Both of compounds 1 and 2 are formed by the connectivity of the Ga-based polyhedral, phosphite/phosphate groups as well as oxalate units. Compound 1 possesses a two-dimensional layer structure, in which the C2O4 units via an in-plane linkage connect two Ga center within the sheet. While in 2, the C2O4 units serve as bis-bidentates ligands bridging two GaO6 octahedra from two distinct gallium-phosphite chains to give rise to inorganic-organic hybrid layer with 8-membered rings. In these materials, the structure-directing amines reside in the interlayer region and interact with the layers by way of hydrogen-bonds.

Phase behaviour and conductivity of supporting electrolytes in supercritical difluoromethane and 1,1-difluoroethane.

PubMed

Han, Xue; Ke, Jie; Suleiman, Norhidayah; Levason, William; Pugh, David; Zhang, Wenjian; Reid, Gillian; Licence, Peter; George, Michael W

2016-06-07

We present investigations into a variety of supporting electrolytes and supercritical fluids probing the phase and conductivity behaviour of these systems and show that they not only provide sufficient electrical conductivity for an electrodeposition bath, but match the requirements imposed by the different precursors and process parameters, e.g. increased temperature, for potential deposition experiments. The two supercritical fluids that have been explored in this study are difluoromethane (CH2F2) and 1,1-difluoroethane (CHF2CH3). For CH2F2, the phase behaviour and electrical conductivity of eight ionic compounds have been studied. Each compound consists of a cation and an anion from the selected candidates i.e. tetramethylammonium ([N(CH3)4](+)), tetrabutylammonium ([N((n)C4H9)4](+)), 1-ethyl-3-methylimidazolium ([EMIM](+)) and 1-butyl-3-methylimidazolium ([BMIM](+)) for cations, and tetrakis(perfluoro-tert-butoxy)aluminate ([Al(OC(CF3)3)4](-)), chloride (Cl(-)), trifluoromethyl sulfonimide ([NTf2](-)) and tris(pentafluoroethyl)trifluorophosphate ([FAP](-)) for anions. For CHF2CH3, [N((n)C4H9)4][BF4] and [N((n)C4H9)4][B{3,5-C6H3(CF3)2}4] have been investigated for comparison with the previously measured solubility and conductivity in CH2F2. We have found that [N((n)C4H9)4][Al(OC(CF3)3)4], [N((n)C4H9)4][FAP] and [N(CH3)4][FAP] have much higher molar conductivity in scCH2F2 at similar conditions than [N((n)C4H9)4][BF4], a widely used commercial electrolyte. Additionally, scCHF2CH3 shows potential for use as the solvent for supercritical fluid electrodeposition, especially at high temperatures since high density of this fluid can be achieved at lower operating pressures than similar fluids that can be used to produce electrochemical baths with comparable conductivity.

Water Soluble Phosphane-Gold(I) Complexes. Applications as Recyclable Catalysts in a Three-component Coupling Reaction and as Antimicrobial and Anticancer Agents

PubMed Central

Elie, Benelita T.; Levine, Chaya; Ubarretxena-Belandia, Iban; Varela-Ramírez, Armando; Aguilera, Renato J.; Ovalle, Rafael; Contel, María

2013-01-01

Water-soluble compounds of the type [AuCl(PR3)] with alkyl-bis-(m-sulfonated-phenyl)-(mC6H4SO3Na)2 and dialkyl-(m-sulfonated-phenyl)-(mC6H4SO3Na) (R = nBu, Cp) phosphanes have been prepared. Dialkyl-phosphane compounds generate water-soluble nanoparticles of 10-15 nm radius when dissolved in water. These air-stable complexes have been evaluated as catalysts in the synthesis of propargylamines via a three-component coupling reaction of aldehydes, amines and alkynes in water. The antimicrobial activity of the new complexes against Gram-positive and Gram-negative bacteria and yeast has been evaluated. The new compounds display moderate to high antibacterial activity. The more lipophilic compounds are also potent against fungi. Their cytotoxic properties have been analyzed in vitro utilizing human Jurkat T-cell acute lymphoblastic leukemia cells. Compounds with dialkyl-(m-sulfonated-phenyl)-(mC6H4SO3Na) phosphanes displayed moderate to high cytotoxicity on this cell line. Death cell mechanism occurs mainly by early apoptosis. The catalytic/biological activity of the previously described compound with commercial m-trisulfonated-triphenylphosphine [AuCl(TPPTS)] (6) has been also evaluated to compare the effects of the higher basicity and lipophilicity of the alkyl- and di-alkyl-(m-sulfonated-phenyl) phosphanes on these new compounds. PMID:23524957

Discovery of (R)-4-cyclopropyl-7,8-difluoro-5-(4-(trifluoromethyl)phenylsulfonyl)-4,5-dihydro-1H-pyrazolo[4,3-c]quinoline (ELND006) and (R)-4-cyclopropyl-8-fluoro-5-(6-(trifluoromethyl)pyridin-3-ylsulfonyl)-4,5-dihydro-2H-pyrazolo[4,3-c]quinoline (ELND007): metabolically stable γ-secretase Inhibitors that selectively inhibit the production of amyloid-β over Notch.

PubMed

Probst, Gary; Aubele, Danielle L; Bowers, Simeon; Dressen, Darren; Garofalo, Albert W; Hom, Roy K; Konradi, Andrei W; Marugg, Jennifer L; Mattson, Matthew N; Neitzel, Martin L; Semko, Chris M; Sham, Hing L; Smith, Jenifer; Sun, Minghua; Truong, Anh P; Ye, Xiaocong M; Xu, Ying-Zi; Dappen, Michael S; Jagodzinski, Jacek J; Keim, Pamela S; Peterson, Brian; Latimer, Lee H; Quincy, David; Wu, Jing; Goldbach, Erich; Ness, Daniel K; Quinn, Kevin P; Sauer, John-Michael; Wong, Karina; Zhang, Hongbin; Zmolek, Wes; Brigham, Elizabeth F; Kholodenko, Dora; Hu, Kang; Kwong, Grace T; Lee, Michael; Liao, Anna; Motter, Ruth N; Sacayon, Patricia; Santiago, Pamela; Willits, Christopher; Bard, Frédérique; Bova, Michael P; Hemphill, Susanna S; Nguyen, Lam; Ruslim, Lany; Tanaka, Kevin; Tanaka, Pearl; Wallace, William; Yednock, Ted A; Basi, Guriqbal S

2013-07-11

Herein, we describe our strategy to design metabolically stable γ-secretase inhibitors which are selective for inhibition of Aβ generation over Notch. We highlight our synthetic strategy to incorporate diversity and chirality. Compounds 30 (ELND006) and 34 (ELND007) both entered human clinical trials. The in vitro and in vivo characteristics for these two compounds are described. A comparison of inhibition of Aβ generation in vivo between 30, 34, Semagacestat 41, Begacestat 42, and Avagacestat 43 in mice is made. 30 lowered Aβ in the CSF of healthy human volunteers.

Comparative studies on performance of CCC and preparative RP-HPLC in separation and purification of steroid saponins from Dioscorea zingiberensis C.H.Wright

PubMed Central

Zhang, Xinxin; Liang, Jinru; Zhang, Yongmin; Liu, Jianli; Sun, Wenji; Ito, Yoichiro

2015-01-01

Steroid saponins from Dioscorea zingiberensis C.H.Wright were separated for the first time using two chromatographic methods for comparison: counter-current chromatography (CCC) coupled with evaporative light scattering detector (ELSD) and preparative reversed phase high-performance liquid chromatography (RP-HPLC) with an ultraviolet detector. Ethyl acetate-n-butanol-methanol-water (4:1:2:4, v/v) was chosen as the two-phase solvent system for CCC, while the acetonitrile-water (25:75 for the first step and15:85 for the second step, v/v) was used as the mobile phase in the preparative RP-HPLC. The following five steroid saponins were purified by theses two chromatographic methods, in one-step operation by CCC and by two-step operation in preparative RP-HPLC: 1) 26-O-β-D- glucopyranosyl-(25R)-furost-5-en-3β, 22ζ, 26-triol-3-O-[β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside (compound A), 2) 26-O-β-D-glucopyranosyl-(25R)-furost-5-en-3β, 22ζ, 4) 26-triol-3-O-[β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside (compound B), 3) 26-O-β-D-glucopyranosyl-(25R)-furost-5-en-3β, 22ζ, 26-triol-3-O-[α-L-rhamnopyranosyl-(1→4)]-β-D-glucopyranoside (compound C), 4) 26-O-β-D-glucopyranosyl-(25R)-furost-5, 20(22)-diene-3β, 26-diol-3-O-{α-L-rhamnopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→2)]}-β-D-glucopyranoside (compound D) and 5) 26-O-β-D-glucopyranosyl-(25R)-furost-5, 20(22)-diene-3β, 26-diol-3-O-[β-D-glucopyranosyl-(1→4)-α-L-rhamnopyranosy-(1→2)]-β-D-glucopyranoside (compound E). The purities of these five steroid saponins separated by both methods were over 95%, and structural identification of these compounds was performed by ESI-MS, and 13C NMR. Comparison of these two established approaches revealed that CCC required a longer separation time but with less solvent consumption, whereas preparative RP-HPLC gave a shorter separation time but with higher solvent consumption. These results demonstrated that either of these two methods of different separation mechanism is feasible, economical and efficient for rapid preparative isolation and purification of steroid saponins from Dioscorea zingiberensis C.H.Wright. PMID:26726306

Comparative studies on performance of CCC and preparative RP-HPLC in separation and purification of steroid saponins from Dioscorea zingiberensis C.H.Wright.

PubMed

Zhang, Xinxin; Liang, Jinru; Zhang, Yongmin; Liu, Jianli; Sun, Wenji; Ito, Yoichiro

2015-03-01

Steroid saponins from Dioscorea zingiberensis C.H.Wright were separated for the first time using two chromatographic methods for comparison: counter-current chromatography (CCC) coupled with evaporative light scattering detector (ELSD) and preparative reversed phase high-performance liquid chromatography (RP-HPLC) with an ultraviolet detector. Ethyl acetate-n-butanol-methanol-water (4:1:2:4, v/v) was chosen as the two-phase solvent system for CCC, while the acetonitrile-water (25:75 for the first step and15:85 for the second step, v/v) was used as the mobile phase in the preparative RP-HPLC. The following five steroid saponins were purified by theses two chromatographic methods, in one-step operation by CCC and by two-step operation in preparative RP-HPLC: 1) 26-O-β-D- glucopyranosyl-(25R)-furost-5-en-3β, 22ζ, 26-triol-3-O-[β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside ( compound A ), 2) 26-O-β-D-glucopyranosyl-(25R)-furost-5-en-3β, 22ζ, 4) 26-triol-3-O-[β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside ( compound B ), 3) 26-O-β-D-glucopyranosyl-(25R)-furost-5-en-3β, 22ζ, 26-triol-3-O-[α-L-rhamnopyranosyl-(1→4)]-β-D-glucopyranoside ( compound C ), 4) 26-O-β-D-glucopyranosyl-(25R)-furost-5, 20(22)-diene-3β, 26-diol-3-O-{α-L-rhamnopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→2)]}-β-D-glucopyranoside ( compound D ) and 5) 26-O-β-D-glucopyranosyl-(25R)-furost-5, 20(22)-diene-3β, 26-diol-3-O-[β-D-glucopyranosyl-(1→4)-α-L-rhamnopyranosy-(1→2)]-β-D-glucopyranoside ( compound E ). The purities of these five steroid saponins separated by both methods were over 95%, and structural identification of these compounds was performed by ESI-MS, and 13 C NMR. Comparison of these two established approaches revealed that CCC required a longer separation time but with less solvent consumption, whereas preparative RP-HPLC gave a shorter separation time but with higher solvent consumption. These results demonstrated that either of these two methods of different separation mechanism is feasible, economical and efficient for rapid preparative isolation and purification of steroid saponins from Dioscorea zingiberensis C.H.Wright.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanjeewa, Liurukara. D.; McGuire, Michael A.; McMillen, Colin D.

We synthesized new complex manganese vanadate materials as high-quality single crystals in multi-millimeter lengths using a high-temperature, high-pressure hydrothermal method. We grew one compound, Mn 5(VO 4) 2(OH) 4, from Mn 2O 3 and V 2O 5 in 3 M CsOH at 580 °C and 1.5 kbar. Changing the mineralizer to 1 M CsOH/3MCsCl leads to the formation of another product, Mn 6O(VO 4) 2(OH). Both compounds were structurally characterized by single-crystal X-ray diffraction (Mn 5(VO 4) 2(OH) 4: C2/m, Z = 2, a = 9.6568(9) Å, b = 9.5627(9) Å, c = 5.4139(6) Å, β = 98.529(8)°; Mn 6O(VOmore » 4) 2(OH): P21/m, Z = 2, a = 8.9363(12) Å, b = 6.4678(8) Å, c = 10.4478(13) Å, β = 99.798(3)°), revealing interesting low-dimensional transition-metal features. Mn 5(VO 4) 2(OH) 4 possesses complex honeycomb-type Mn–O layers, built from edge-sharing [MnO 6] octahedra in the bc plane, with bridging vanadate groups connecting these layers along the a-axis. Mn 6O(VO 4) 2(OH) presents a more complicated structure with both octahedral [MnO 6] and trigonal bipyramidal [MnO 5] units. A different pattern of planar honeycomb sheets are formed by edge-shared [MnO6] octahedra, and these sublattices are connected through edge-shared dimers of [MnO 5] trigonal bipyramids to form corrugated sheets. Vanadate groups again condense the sheets into a three-dimensional framework. Infrared and Raman spectroscopies indicated the presence of OH groups and displayed characteristic Raman scattering due to vanadate groups. Furthermore, temperature-dependent magnetic studies indicated Curie–Weiss behavior above 100 K with significant anti-ferromagnetic coupling for both compounds, with further complex magnetic behavior at lower temperatures. The data indicate canted anti-ferromagnetic order below 57 K in Mn 5(VO 4) 2(OH) 4 and below 45 K in Mn 6O(VO 4) 2(OH). Members of another class of compounds, K 2M 3(VO 4) 2(OH) 2 (M = Mn, Co), also containing a honeycomb-type sublattice, were also synthesized to allow a comparison of the structural features across all three structure types and to demonstrate extension to other transition metals.« less

CALIX[4]ARENE C-99 INHIBITS MYOSIN ATPase ACTIVITY AND CHANGES THE ORGANIZATION OF CONTRACTILE FILAMENTS OF MYOMETRIUM.

PubMed

Labyntseva, R D; Bevza, A A; Lul'ko, A O; Cherenok, S O; Kalchenko, V I; Kosterin, S O

2015-01-01

Calix[4]arenes are cup-like macrocyclic (polyphenolic) compounds, they are regarded as promising molecular "platforms" for the design of new physiologically active compounds. We have earlier found that calix[4]arene C-99 inhibits the ATPase activity of actomyosin and myosin subfragment-1 of pig uterus in vitro. The aim of this study was to investigate the interaction of calix[4]arene C-99 with myosin from rat uterine myocytes. It was found that the ATPase activity of myosin prepared from pre-incubated with 100 mM of calix[4]arene C-99 myocytes was almost 50% lower than in control. Additionally, we have revealed the effect of calix[4]arene C-99 on the subcellular distribution of actin and myosin in uterus myocytes by the method of confocal microscopy. This effect can be caused by reorganization of the structure of the contractile smooth muscle cell proteins due to their interaction with calix[4]arene. The obtained results demonstrate the ability of calix[4]arene C-99 to penetrate into the uterus muscle cells and affect not only the myosin ATPase activity, but also the structure of the actin and myosin filaments in the myometrial cells. Demonstrated ability of calix[4]arene C-99 can be used for development of new pharmacological agents for efficient normalization of myometrial contractile hyperfunction.

Synthesis, structural characterization and DFT calculation on a square-planar Ni(II) complex of a compartmental Schiff base ligand

NASA Astrophysics Data System (ADS)

Biswas, Surajit; Dolai, Malay; Dutta, Arpan; Ali, Mahammad

2016-12-01

Reaction of a symmetric compartmental Schiff-base ligand, (H2L) with nickel(II) perchlorate hexahydrate in 1:1 M ratio in methanol gives rise to a mononuclear nickel(II) compound, NiL (1). The compound has been characterized by C, H, N microanalyses and UV-Vis spectra. The single crystal X-ray diffraction studies reveal a square planar geometry around the Ni(II) center. The compound crystallizes in monoclinic system with space group C2/c with a = 21.6425(6), b = 9.9481(3), c = 13.1958(4) Å, β = 107.728(2)°, V = 2706.16(14) Å3 and Z = 4. Ground state DFT optimization and TDDFT calculations on the ligand and complex were performed to get their UV-Vis spectral pattern.

Inhibition of in vitro leukotriene B4 biosynthesis in human neutrophil granulocytes and docking studies of natural quinones.

PubMed

Landa, Premysl; Kutil, Zsofia; Temml, Veronika; Malik, Jan; Kokoska, Ladislav; Widowitz, Ute; Pribylova, Marie; Dvorakova, Marcela; Marsik, Petr; Schuster, Daniela; Bauer, Rudolf; Vanek, Tomas

2013-01-01

Quinones are compounds frequently contained in medicinal plants used for the treatment of inflammatory diseases. Therefore, the impact of plant-derived quinones on the arachidonic acid metabolic pathway is worthy of investigation. In this study, twenty-three quinone compounds of plant origin were tested in vitro for their potential to inhibit leukotriene B4 (LTB4) biosynthesis in activated human neutrophil granulocytes with 5-lipoxygenase (5-LOX) activity. The benzoquinones primin (3) and thymohydroquinone (4) (IC50 = 4.0 and 4.1 microM, respectively) showed activity comparable with the reference inhibitor zileuton (1C50 = 4.1 microM). Moderate activity was observed for the benzoquinone thymoquinone (2) (1C50 = 18.2 microM) and the naphthoquinone shikonin (1) (IC50 = 24.3 microM). The anthraquinone emodin and the naphthoquinone plumbagin (5) displayed only weak activities (IC50 > 50 microM). The binding modes of the active compounds were further evaluated in silico by molecular docking to the human 5-LOX crystal structure. This process supports the biological data and suggested that, although the redox potential is responsible for the quinone's activity on multiple targets, in the case of 5-LOX the molecular structure plays a vital role in the inhibition. The obtained results suggest primin as a promising compound for the development of dual COX-2/5-LOX inhibitors.

Discovery of gigantic molecular nanostructures using a flow reaction array as a search engine.

PubMed

Zang, Hong-Ying; de la Oliva, Andreu Ruiz; Miras, Haralampos N; Long, De-Liang; McBurney, Roy T; Cronin, Leroy

2014-04-28

The discovery of gigantic molecular nanostructures like coordination and polyoxometalate clusters is extremely time-consuming since a vast combinatorial space needs to be searched, and even a systematic and exhaustive exploration of the available synthetic parameters relies on a great deal of serendipity. Here we present a synthetic methodology that combines a flow reaction array and algorithmic control to give a chemical 'real-space' search engine leading to the discovery and isolation of a range of new molecular nanoclusters based on [Mo(2)O(2)S(2)](2+)-based building blocks with either fourfold (C4) or fivefold (C5) symmetry templates and linkers. This engine leads us to isolate six new nanoscale cluster compounds: 1, {Mo(10)(C5)}; 2, {Mo(14)(C4)4(C5)2}; 3, {Mo(60)(C4)10}; 4, {Mo(48)(C4)6}; 5, {Mo(34)(C4)4}; 6, {Mo(18)(C4)9}; in only 200 automated experiments from a parameter space spanning ~5 million possible combinations.

A Novel Access to Arylated and Heteroarylated Beta-Carboline Based PDE5 Inhibitors

PubMed Central

Ahmed, Nermin S.; Gary, Bernard D.; Piazza, Gary A.; Tinsley, Heather N.; Laufer, Stefan; Abadi, Ashraf H.

2016-01-01

Starting from a previously reported lead compound GR30040X (a hydantoin tetrahydro-β-carboline derivative with a 4- pyridinyl ring at C- 5), a series of structurally related tetrahydro-β-carboline derivatives were prepared. The tet-rahydro-β-carboline skeleton was fused either to a hydantoin or to a piperazindione ring, the pendant aryl group attached to C-5 or C-6 was changed to a 3, 4-dimethoxyphenyl or a 3-pyridinyl ring; different N-substituents on the terminal ring were introduced, a straight chain ethyl group, a branched tert. butyl and P-chlorophenyl group rather than n-butyl group of the lead compound. All four possible diastereomers of target tetrahydro-β-carboline derivatives were prepared, separated by column chromatography and the significance of these stereochemical manipulations was studied. Synthesized compounds were evaluated for their inhibitory effect versus PDE5. Seven hits were obtained with appreciable inhibitory activity versus PDE5 with IC50s 0.14 - 4.99 μM. PMID:21054274

Synthesis and Evaluation of New 1,3,4-Thiadiazole Derivatives as Antinociceptive Agents.

PubMed

Altıntop, Mehlika Dilek; Can, Özgür Devrim; Demir Özkay, Ümide; Kaplancıklı, Zafer Asım

2016-08-01

In the current work, new 1,3,4-thiadiazole derivatives were synthesized and investigated for their antinociceptive effects on nociceptive pathways of nervous system. The effects of these compounds against mechanical, thermal and chemical stimuli were evaluated by tail-clip, hot-plate and acetic acid-induced writhing tests, respectively. In addition, activity cage was performed to assess the locomotor activity of animals. The obtained data indicated that compounds 3b, 3c, 3d, 3e, 3g and 3h increased the reaction times of mice both in the hot-plate and tail-clip tests, indicating the centrally mediated antinociceptive activity of these compounds. Additionally, the number of writhing behavior was significantly decreased by the administration of compounds 3a, 3c, 3e and 3f, which pointed out the peripherally mediated antinociceptive activity induced by these four compounds. According to the activity cage tests, compounds 3a, 3c and 3f significantly decreased both horizontal and vertical locomotor activity of mice. Antinociceptive behavior of these three compounds may be non-specific and caused by possible sedative effect or motor impairments.

Microsporols A-C from the Plant Endophytic Fungus Pestalotiopsis microspore.

PubMed

Wu, Xianfu; Wang, Yadan; Liu, Shuchun; Liu, Xinzhong; Guo, Liangdong

2015-10-01

Three new ambuic acid derivatives, microsporols A-C (1-3) and the known compound ambuic acid (4), were isolated from the solid-substrate fermentation cultures of the plant endophytic fungus Pestalotiopsis microspora. Their structures were elucidated primarily by NMR experiments. The absolute configurations of the 6,7-diol moiety in 1 and 2 were assigned using the Snatzke's method, whereas that of 3 was deduced by circular dichroism (CD) exciton chirality method. Compounds 1, 3, and 4 showed moderate 5-lipoxygenase (5-LOX) inhibitory effects.

Efficient synthesis and antimicrobial activity of some novel S-β-d-glucosides of 5-aryl-1,2,4-triazole-3-thiones derivatives.

PubMed

Ji, Dan; Lu, JunRui; Lu, BoWei; Xin, ChunWei; Mu, JiangBei; Li, JianFa; Peng, ChunYong; Bao, XiuRong

2013-04-01

A series of 3-S-β-d-glucosides-4-arylideneamino-5-aryl-1,2,4-triazoles were rationally designed and synthesized according to the principle of superposition of bioactive substructures by the combination of 1,2,4-triazole, Schiff base and glucosides. The structures of the target compounds have been characterized by (1)H NMR, (13)C NMR, IR, MS and HRMS. All the newly synthesized compounds have been evaluated for their antimicrobial activities in vitro against Staphylococcus aureus (ATCC 6538), Escherichia coli (ATCC 8099) as well as Monilia albican (ATCC 10231). The bioactive assay showed that most of the tested compounds displayed variable inhibitory effects on the growth of the Gram-positive bacterial strain (Staphylococcus aureus), Gram-negative bacterial strains (Escherichia coli) and fungal strains (Monilia albican). All the target compounds exhibited better antifungal activity than antibacterial activity. Especially, compounds 6b, 6c, 6f, 6j, 6k and 6l showed excellent activity against fungus Monilia albican with MIC values of 16 μg/mL. Copyright © 2013 Elsevier Ltd. All rights reserved.

Allelopathic Polyketides from an Endolichenic Fungus Myxotrichum SP. by Using OSMAC Strategy.

PubMed

Yuan, Chao; Guo, Yu-Hua; Wang, Hai-Ying; Ma, Xiao-Jun; Jiang, Tao; Zhao, Jun-Ling; Zou, Zhong-Mei; Ding, Gang

2016-02-03

Three new polyketides myxotritones A-C (2-4), together with a new natural product 7,8-dihydro-7R,8S-dihydroxy-3,7-dimethyl-2-benzopyran-6-one (1) were obtained from the endolichenic fungus Myxotrichum sp. by using OMSAC (One Strain, Many Compounds) method. The planar structures of these new compounds were determined by NMR experiment and HRESIMS data, and the absolute configuration of 1 was established by X-ray diffraction, and the stereochemistry of the new compounds 2-4 were determined by same biosynthesis origin, and similar CD spectra with 1. Allelopathic test showed that compound 4 significantly retarded root elongation of Arabidopsis thaliana seed, indicating that this fungus might contribute to the defense of its host lichen. From the view of biosynthetic pathway, all four compounds 1-4 might be originated from Non-Reduced Polyketide synthase (NR-PKS).

η(4) -HBCC-σ,π-Borataallyl Complexes of Ruthenium Comprising an Agostic Interaction.

PubMed

Saha, Koushik; Joseph, Benson; Ramalakshmi, Rongala; Anju, R S; Varghese, Babu; Ghosh, Sundargopal

2016-06-01

Thermolysis of [Cp*Ru(PPh2 (CH2 )PPh2 )BH2 (L2 )] 1 (Cp*=η(5) -C5 Me5 ; L=C7 H4 NS2 ), with terminal alkynes led to the formation of η(4) -σ,π-borataallyl complexes [Cp*Ru(μ-H)B{R-C=CH2 }(L)2 ] (2 a-c) and η(2) -vinylborane complexes [Cp*Ru(R-C=CH2 )BH(L)2 ] (3 a-c) (2 a, 3 a: R=Ph; 2 b, 3 b: R=COOCH3 ; 2 c, 3 c: R=p-CH3 -C6 H4 ; L=C7 H4 NS2 ) through hydroboration reaction. Ruthenium and the HBCC unit of the vinylborane moiety in 2 a-c are linked by a unique η(4) -interaction. Conversions of 1 into 3 a-c proceed through the formation of intermediates 2 a-c. Furthermore, in an attempt to expand the library of these novel complexes, chemistry of σ-borane complex [Cp*RuCO(μ-H)BH2 L] 4 (L=C7 H4 NS2 ) was investigated with both internal and terminal alkynes. Interestingly, under photolytic conditions, 4 reacts with methyl propiolate to generate the η(4) -σ,π-borataallyl complexes [Cp*Ru(μ-H)BH{R-C=CH2 }(L)] 5 and [Cp*Ru(μ-H)BH{HC=CH-R}(L)] 6 (R=COOCH3 ; L=C7 H4 NS2 ) by Markovnikov and anti-Markovnikov hydroboration. In an extension, photolysis of 4 in the presence of dimethyl acetylenedicarboxylate yielded η(4) -σ,π-borataallyl complex [Cp*Ru(μ-H)BH{R-C=CH-R}(L)] 7 (R=COOCH3 ; L=C7 H4 NS2 ). An agostic interaction was also found to be present in 2 a-c and 5-7, which is rare among the borataallyl complexes. All the new compounds have been characterized in solution by IR, (1) H, (11) B, (13) C NMR spectroscopy, mass spectrometry and the structural types were unequivocally established by crystallographic analysis of 2 b, 3 a-c and 5-7. DFT calculations were performed to evaluate possible bonding and electronic structures of the new compounds. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and antibacterial activity of bis-[2-hydroxy-3-(1,7,8,9,10-pentamethyl-3,5-dioxo-4-aza-tricyclo[5.2.1.0(2,6)]dec-8-en-4-yloxy)-propyl]-dimethyl-ammonium chloride.

PubMed

Struga, Marta; Kossakowski, Jerzy; Stefańska, Joanna; Zimniak, Andrzej; Koziol, Anna E

2008-06-01

A new quaternary ammonium compound, bis-[2-hydroxy-3-(1,7,8,9,10-pentamethyl-3,5-dioxo-4-aza-tricyclo[5.2.1.0(2,6)]dec-8-en-4-yloxy)-propyl]-dimethyl-ammonium chloride (4), was synthesized. The compound was investigated for antibacterial activity, including Gram-positive cocci and Gram-negative rods, and antifungal activity. Compound 4 showed significant inhibition against Staphylococcus aureus. Research was carried out over 4 standard strains and 40 hospital strains. Elementary analysis and/or MS, (1)H NMR and (13)C NMR spectra confirmed the identity of the products. The molecular structure of 3 was determined by an X-ray analysis.

Synthesis of five- and six-coordinate tris(pentafluoroethyl)fluorosilicates.

PubMed

Steinhauer, Simon; Stammler, Hans-Georg; Neumann, Beate; Ignat'ev, Nikolai; Hoge, Berthold

2014-01-07

The research area of perfluoroalkylsilanes is still in its infancy. Although there are already many examples of difluorotriorganylsilicates, the first example of a completely characterized trifluorotriorganylsilicate is presented, the dianion [Si(C2 F5 )3 F3 ](2-) . The strongly electron-withdrawing influence of the pentafluoroethyl groups appears to be a fundamental cause of the stability of this compound. This dianion is also the first structurally characterized example of a tris(pentafluoroethyl)silicon compound. The synthesis and complete characterization of [PPh4 ]2 [Si(C2 F5 )3 F3 ] and [PPh4 ][Si(C2 F5 )3 F2 ] along with the precursor [H(OEt2 )2 ][Si(C2 F5 )3 F2 ] was achieved from SiCl4 and LiC2 F5 . Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of some novel orcinol based coumarin triazole hybrids with capabilities to inhibit RANKL-induced osteoclastogenesis through NF-κB signaling pathway.

PubMed

Rama Krishna, Boddu; Thummuri, Dinesh; Naidu, V G M; Ramakrishna, Sistla; Venkata Mallavadhani, Uppuluri

2018-08-01

A total of twenty-two novel coumarin triazole hybrids (4a-4k and 6a-6k) were synthesized from orcinol in good to excellent yields of 70-94%. The structures of all the synthesized compounds were elucidated by spectroscopic techniques such as 1 H NMR, 13 C NMR, and HRMS. The anti-inflammatory potential of synthesized compounds was investigated against the proinflammatory cytokine, TNF-α on U937 cell line and compounds 4d, 4j, and 6j were found to exhibit promising anti-inflammatory activity. These three compounds were further screened against TNF-α on LPS-stimulated RAW 264.7 cells, which confirm their anti-inflammatory potential. Furthermore, the above said active compounds were tested for their inhibitory effect on RANKL-induced osteoclastogenesis in RAW 264.7 cells by using tartrate resistant acid phosphatase (TRAP) staining assay at 10 µM. Molecular mechanism studies demonstrated that compound 4d exhibited dose dependent inhibition of RANKL-induced osteoclastogenesis by suppression of the NF-kB pathway. Thus, compound 4d is a promising candidate for further optimization to develop as a potent anti-osteoporotic agent. Copyright © 2018 Elsevier Inc. All rights reserved.

Hydrogen-fluorine exchange in NaBH4-NaBF4.

PubMed

Rude, L H; Filsø, U; D'Anna, V; Spyratou, A; Richter, B; Hino, S; Zavorotynska, O; Baricco, M; Sørby, M H; Hauback, B C; Hagemann, H; Besenbacher, F; Skibsted, J; Jensen, T R

2013-11-07

Hydrogen-fluorine exchange in the NaBH4-NaBF4 system is investigated using a range of experimental methods combined with DFT calculations and a possible mechanism for the reactions is proposed. Fluorine substitution is observed using in situ synchrotron radiation powder X-ray diffraction (SR-PXD) as a new Rock salt type compound with idealized composition NaBF2H2 in the temperature range T = 200 to 215 °C. Combined use of solid-state (19)F MAS NMR, FT-IR and DFT calculations supports the formation of a BF2H2(-) complex ion, reproducing the observation of a (19)F chemical shift at -144.2 ppm, which is different from that of NaBF4 at -159.2 ppm, along with the new absorption bands observed in the IR spectra. After further heating, the fluorine substituted compound becomes X-ray amorphous and decomposes to NaF at ~310 °C. This work shows that fluorine-substituted borohydrides tend to decompose to more stable compounds, e.g. NaF and BF3 or amorphous products such as closo-boranes, e.g. Na2B12H12. The NaBH4-NaBF4 composite decomposes at lower temperatures (300 °C) compared to NaBH4 (476 °C), as observed by thermogravimetric analysis. NaBH4-NaBF4 (1:0.5) preserves 30% of the hydrogen storage capacity after three hydrogen release and uptake cycles compared to 8% for NaBH4 as measured using Sievert's method under identical conditions, but more than 50% using prolonged hydrogen absorption time. The reversible hydrogen storage capacity tends to decrease possibly due to the formation of NaF and Na2B12H12. On the other hand, the additive sodium fluoride appears to facilitate hydrogen uptake, prevent foaming, phase segregation and loss of material from the sample container for samples of NaBH4-NaF.

Crystal structures of hibiscus acid and hibiscus acid dimethyl ester isolated from Hibiscus sabdariffa (Malvaceae).

PubMed

Zheoat, Ahmed M; Gray, Alexander I; Igoli, John O; Kennedy, Alan R; Ferro, Valerie A

2017-09-01

The biologically active title compounds have been isolated from Hibiscus sabdariffa plants, hibiscus acid as a dimethyl sulfoxide monosolvate [systematic name: (2 S ,3 R )-3-hy-droxy-5-oxo-2,3,4,5-tetra-hydro-furan-2,3-di-carb-oxy-lic acid dimethyl sulfoxide monosolvate], C 6 H 6 O 7 ·C 2 H 6 OS, (I), and hibiscus acid dimethyl ester [systematic name: dimethyl (2 S ,3 R )-3-hy-droxy-5-oxo-2,3,4,5-tetra-hydro-furan-2,3-di-carboxyl-ate], C 8 H 10 O 7 , (II). Compound (I) forms a layered structure with alternating layers of lactone and solvent mol-ecules, that include a two-dimensional hydrogen-bonding construct. Compound (II) has two crystallographically independent and conformationally similar mol-ecules per asymmetric unit and forms a one-dimensional hydrogen-bonding construct. The known absolute configuration for both compounds has been confirmed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Chiu Tung; Chan, Man Nin; Wilson, Kevin R.

Oxygenated organic molecules are abundant in atmospheric aerosols and are transformed by oxidation reactions near the aerosol surface by gas-phase oxidants such as hydroxyl (OH) radicals. To gain better insights into how the structure of an organic molecule, particularly in the presence of hydroxyl groups, controls the heterogeneous reaction mechanisms of oxygenated organic compounds, this study investigates the OH-radical initiated oxidation of aqueous tartaric acid (C 4 H 6 O 6 ) droplets using an aerosol flow tube reactor. The molecular composition of the aerosols before and after reaction is characterized by a soft atmospheric pressure ionization source (Direct Analysismore » in Real Time) coupled with a high-resolution mass spectrometer. The aerosol mass spectra reveal that four major reaction products are formed: a single C 4 functionalization product (C 4 H 4 O 6 ) and three C 3 fragmentation products (C 3 H 4 O 4 , C 3 H 2 O 4 , and C 3 H 2 O 5 ). The C 4 functionalization product does not appear to originate from peroxy radical self-reactions but instead forms via an α-hydroxylperoxy radical produced by a hydrogen atom abstraction by OH at the tertiary carbon site. The proximity of a hydroxyl group to peroxy group enhances the unimolecular HO 2 elimination from the α-hydroxylperoxy intermediate. This alcohol-to-ketone conversion yields 2-hydroxy-3-oxosuccinic acid (C 4 H 4 O 6 ), the major reaction product. While in general, C-C bond scission reactions are expected to dominate the chemistry of organic compounds with high average carbon oxidation states (OS C ), our results show that molecular structure can play a larger role in the heterogeneous transformation of tartaric acid (OS C = 1.5). These results are also compared with two structurally related dicarboxylic acids (succinic acid and 2,3-dimethylsuccinic acid) to elucidate how the identity and location of functional groups (methyl and hydroxyl groups) alter heterogeneous reaction mechanisms.« less

Neuroprotective Properties of Compounds Extracted from Dianthus superbus L. against Glutamate-induced Cell Death in HT22 Cells

PubMed Central

Yun, Bo-Ra; Yang, Hye Jin; Weon, Jin Bae; Lee, Jiwoo; Eom, Min Rye; Ma, Choong Je

2016-01-01

Background: Dianthus superbus L. has been used in Chinese herbal medicine as a diuretic and anti-inflammatory agent. Objective: In this study, we isolated ten bioactive compounds from D. superbus and evaluated their neuroprotective activity against glutamate-induced cell death in the hippocampal neuronal HT22 cells. Materials and Methods: New compound, (E)-methyl-4-hydroxy-4-(8a-methyl-3-oxodecahydronaphthalen-4a-yl) (1) and, nine known compounds, diosmetin-7-O (2’’,6’’-di-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside (2), 4-hydroxy-3-methoxy-pentyl ester benzenepropanoic acid (3), vanillic acid (4), 4-hydroxy-benzeneacetic acid (5), 4-methoxybenzeneacetic acid (6), (E)-4-methoxycinnamic acid (7), 3-methoxy-4-hydroxyphenylethanol (8), hydroferulic acid (9), and methyl hydroferulate (10), were isolated by bioactivity-guided separation. Structures of the isolated compounds were identified on the basis of 1H nuclear magnetic resonance (NMR), 13C NMR, and two-dimensional NMR spectra, while their neuroprotective properties were evaluated by performing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Results: D. superbus extract had a neuroprotective effect and isolated 10 compounds. Among the compounds, compounds 5 and 6 effectively protected HT22 cells against glutamate toxicity. Conclusion: In conclusion, the extract of D. superbus and compounds isolated from it exhibited neuroprotective properties, suggesting therapeutic potential for applications in neurotoxic diseases. SUMMARY D. superbus extract significantly protected on glutamate-induced cell death in HT22 cellsNew compound, (E)-methyl-4-hydroxy-4-(8a-methyl-3-oxodecahydronaphthalen-4a-yl) (1) and, nine known compounds, diosmetin-7-O(2’’,6’’-di-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside (2), 4-hydroxy-3-methoxy-pentyl ester benzenepropanoic acid (3), vanillic acid (4), 4-hydroxy-benzeneacetic acid (5), 4-methoxybenzeneacetic acid (6), (E)-4-methoxycinnamic acid (7), 3-methoxy-4-hydroxyphenylethanol (8), hydroferulic acid (9), and methyl hydroferulate (10) were isolated from D. superbus extract4-hydroxy-benzeneacetic acid and 4-methoxybenzeneacetic acid showed significant protective activity against glutamate-induced toxicity in HT22 cells. Abbreviations used: CNS: Central nervous system, ROS: Reactive oxygen species, CHCl3: Chloroform, EtOAc: Ethyl acetate, BuOH: Butanol, HPLC: High performance liquid chromatography, TLC: Thin layer chromatography, MPLC: Middle performance liquid chromatography, MeOH: Methanol, OD: Optical density, COSY: Correlation spectroscopy, HMQC: Heteronuclear multiple-quantum correlation, HMBC: Heteronuclear multiple-bond correlation, HR-MS: High-resolution molecular spectroscopy, MTT: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. PMID:27076746

Neuroprotective Properties of Compounds Extracted from Dianthus superbus L. against Glutamate-induced Cell Death in HT22 Cells.

PubMed

Yun, Bo-Ra; Yang, Hye Jin; Weon, Jin Bae; Lee, Jiwoo; Eom, Min Rye; Ma, Choong Je

2016-01-01

Dianthus superbus L. has been used in Chinese herbal medicine as a diuretic and anti-inflammatory agent. In this study, we isolated ten bioactive compounds from D. superbus and evaluated their neuroprotective activity against glutamate-induced cell death in the hippocampal neuronal HT22 cells. New compound, (E)-methyl-4-hydroxy-4-(8a-methyl-3-oxodecahydronaphthalen-4a-yl) (1) and, nine known compounds, diosmetin-7-O (2'',6''-di-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside (2), 4-hydroxy-3-methoxy-pentyl ester benzenepropanoic acid (3), vanillic acid (4), 4-hydroxy-benzeneacetic acid (5), 4-methoxybenzeneacetic acid (6), (E)-4-methoxycinnamic acid (7), 3-methoxy-4-hydroxyphenylethanol (8), hydroferulic acid (9), and methyl hydroferulate (10), were isolated by bioactivity-guided separation. Structures of the isolated compounds were identified on the basis of (1)H nuclear magnetic resonance (NMR), (13)C NMR, and two-dimensional NMR spectra, while their neuroprotective properties were evaluated by performing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. D. superbus extract had a neuroprotective effect and isolated 10 compounds. Among the compounds, compounds 5 and 6 effectively protected HT22 cells against glutamate toxicity. In conclusion, the extract of D. superbus and compounds isolated from it exhibited neuroprotective properties, suggesting therapeutic potential for applications in neurotoxic diseases. D. superbus extract significantly protected on glutamate-induced cell death in HT22 cellsNew compound, (E)-methyl-4-hydroxy-4-(8a-methyl-3-oxodecahydronaphthalen-4a-yl) (1) and, nine known compounds, diosmetin-7-O(2'',6''-di-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside (2), 4-hydroxy-3-methoxy-pentyl ester benzenepropanoic acid (3), vanillic acid (4), 4-hydroxy-benzeneacetic acid (5), 4-methoxybenzeneacetic acid (6), (E)-4-methoxycinnamic acid (7), 3-methoxy-4-hydroxyphenylethanol (8), hydroferulic acid (9), and methyl hydroferulate (10) were isolated from D. superbus extract4-hydroxy-benzeneacetic acid and 4-methoxybenzeneacetic acid showed significant protective activity against glutamate-induced toxicity in HT22 cells. Abbreviations used: CNS: Central nervous system, ROS: Reactive oxygen species, CHCl3: Chloroform, EtOAc: Ethyl acetate, BuOH: Butanol, HPLC: High performance liquid chromatography, TLC: Thin layer chromatography, MPLC: Middle performance liquid chromatography, MeOH: Methanol, OD: Optical density, COSY: Correlation spectroscopy, HMQC: Heteronuclear multiple-quantum correlation, HMBC: Heteronuclear multiple-bond correlation, HR-MS: High-resolution molecular spectroscopy, MTT: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide.

Synthesis, spectroscopic characterization and in vitro antimicrobial, anticancer and antileishmanial activities as well interaction with Salmon sperm DNA of newly synthesized carboxylic acid derivative, 4-(4-methoxy-2-nitrophenylamino)-4-oxobutanoic acid

NASA Astrophysics Data System (ADS)

Sirajuddin, Muhammad; Ali, Saqib; McKee, Vickie; Ullah, Hameed

2015-03-01

This paper stresses on the synthesis, characterization of novel carboxylic acid derivative and its application in pharmaceutics. Carboxylic acid derivatives have a growing importance in medicine, particularly in oncology. A novel carboxylic acid, 4-(4-methoxy-2-nitrophenylamino)-4-oxobutanoic acid, was synthesized and characterized by elemental analysis, FT-IR, NMR (1H, and 13C), mass spectrometry and single crystal X-ray structural analysis. The structure of the title compound, C11H12N2O6, shows the molecules dimerised by short intramolecular Osbnd H⋯O hydrogen bonds. The compound was screened for in vitro antimicrobial, anticancer, and antileishmanial activities as well as interaction with SS-DNA. The compound was also checked for in vitro anticancer activity against BHK-21, H-157 and HCEC cell lines, and showed significant anticancer activity. The compound was almost non-toxic towards human corneal epithelial cells (HCEC) and did not show more than 7.4% antiproliferative activity when used at the 2.0 μg/mL end concentration. It was also tested for antileishmanial activity against the promastigote form of leishmania major and obtained attractive result. DNA interaction study exposes that the binding mode of the compound with SS-DNA is an intercalative as it results in hypochromism along with minor red shift. A new and efficient strategy to identify pharmacophores sites in carboxylic acid derivative for antibacterial/antifungal activity using Petra, Osiris and Molinspiration (POM) analyses was also carried out.

Leishmanicidal Activities of Novel Synthetic Furoxan and Benzofuroxan Derivatives

PubMed Central

Dutra, Luiz Antônio; de Almeida, Letícia; Passalacqua, Thais G.; Reis, Juliana Santana; Torres, Fabio A. E.; Martinez, Isabel; Peccinini, Rosangela Gonçalves; Chin, Chung Man; Chegaev, Konstantin; Guglielmo, Stefano; Fruttero, Roberta

2014-01-01

A novel series of furoxan (1,2,5-oxadiazole 2-oxide) (compounds 3, 4a and -b, 13a and -b, and 14a to -f) and benzofuroxan (benzo[c][1,2,5]oxadiazole 1-oxide) (compounds 7 and 8a to -c) derivatives were synthesized, characterized, and evaluated for in vitro activity against promastigote and intracellular amastigote forms of Leishmania amazonensis. The furoxan derivatives exhibited the ability to generate nitric oxide at different levels (7.8% to 27.4%). The benzofuroxan derivative 8a was able to increase nitrite production in medium supernatant from murine macrophages infected with L. amazonensis at 0.75 mM after 48 h. Furoxan and benzofuroxan derivatives showed remarkable leishmanicidal activity against both promastigote and intracellular amastigote forms. Compounds 8a, 14a and -b, and 14d exerted selective leishmanicidal activities superior to those of amphotericin B and pentamidine. In vitro studies at pH 5.4 reveal that compound 8a is stable until 8 h and that compound 14a behaves as a prodrug, releasing the active aldehyde 13a. These compounds have emerged as promising novel drug candidates for the treatment of leishmaniasis. PMID:24913171

Crystallographic study of three coronary vasodilators of the nitrate ester type: 1,4- trans-cyclohexanedimethanol dinitrate, 1,4:3,6-dianhydro- D-glucitol-2,5-dinitrate and 1,4:3,6-dianhydro- D-glucitol-2-mononitrate

NASA Astrophysics Data System (ADS)

Kanters, J. A.; Schouten, A.; Sterk, G. J.; de Jong, M. H.

1993-10-01

The crystal structures of three vasodilators of the nitrate ester type have been determined by X-ray diffraction. Compound I, 1,4- trans-cyclohexanedimethanol dinitrate (CDDN), C 8H 14N 2O 6, is a recently developed nitrate ester with a promising haemodynamic profile in the treatment of ischaemic heart diseases. CDDN crystallizes in space group P2 1/a with a = 5.9443(4), b = 16.7052(9), c = 6.2022(2) Å, β = 116.669(4)°, Z = 2 and T = 295 K. The molecule lies on a centre of inversion and the structure refined to R = 0.042 for 991 reflections with I > 2.5σ( I). The cyclohexane ring approaches an ideal chair conformation and the C-O-NO 2 fragment is strictly planar. Compound II is the widely applied vasodilator in angina pectoris, isosorbide dinitrate or 1,4:3,6-dianhydro- D-glucitol-2,5-dinitrate (ISDN), C 6H 8N 2O 8. ISDN crystallizes in space group P22 12 1 with a = 5.7535(2), b = 10.9393(5), c = 14.6599(5)Å, Z = 4 and T = 295 K. The structure refined to R = 0.033 for 1104 reflections with I > 2.5σ( I). The molecular skeleton consists of two cis-fused five-membered rings, which each adopt an envelope conformation such that the torsion angels about the central CC bond are 0.3(2) and -7.8(2)°. The angle between the rings is 60.8(1)° and the two nitrate groups are planar. Compound III, isosorbide-2-mononitrate or 1,4:3,6-dianhydro- D-glucitol-2-mononitrate (IS-2MN), C 6H 9NO 6, is an active metabolite of II and crystallizes in space group P2 12 12 1 with a = 6.4318(4), b = 7.5273(4), c = 15.866(1)Å Z = 4 and T = 100 K. The structure refined to R = 0.031 for 1488 reflections with I > 2.5σ( I). The skeleton of III is very similar to that of II. The torsion angles about the central CC bond are 2.4(2) and -3.1(2)°, the interplanar angle is 61.5(1)° and the nitrate group is strictly planar.

Study of the ferroelastic phase transition in the tetraethylammonium compound [N(C{sub 2}H{sub 5}){sub 4}]{sub 2}ZnBr{sub 4} by magic-angle spinning and static NMR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lim, Ae Ran, E-mail: aeranlim@hanmail.net, E-mail: arlim@jj.ac.kr

The ferroelastic phase transition of tetraethylammonium compound [N(C{sub 2}H{sub 5}){sub 4}]{sub 2}ZnBr{sub 4} at the phase transition temperature (T{sub C}) = 283 K was characterized by magic-angle spinning (MAS) and static nuclear magnetic resonance (NMR), and confirmed by optical polarizing spectroscopy. The structural geometry near T{sub C} was studied in terms of the chemical shifts and the spin-lattice relaxation times T{sub 1ρ} in the rotating frame for {sup 1}H MAS NMR and {sup 13}C cross-polarization (CP)/MAS NMR. The two inequivalent ethyl groups were distinguishable in the {sup 13}C NMR spectrum, and the T{sub 1ρ} results indicate that they undergo tumblingmore » motion above T{sub C} in a coupled manner. From the {sup 14}N NMR results, the two nitrogen nuclei in the N(C{sub 2}H{sub 5}){sub 4}{sup +} ions were distinguishable above T{sub C}, and the splitting in the spectra below T{sub C} was related to the ferroelastic domains with different orientations.« less

Design of hydrophobic polyoxometalate hybrid assemblies beyond surfactant encapsulation.

PubMed

Song, Yu-Fei; McMillan, Nicola; Long, De-Liang; Thiel, Johannes; Ding, Yulong; Chen, Haisheng; Gadegaard, Nikolaj; Cronin, Leroy

2008-01-01

Grafting of C-6, C-16 and C-18 alkyl chains onto the hydrophilic Mn-Anderson clusters (compounds 2-4) has been achieved. Exchange of the tetrabutyl ammonium (TBA) with dimethyldioctadecyl ammonium (DMDOA) results in the formation of new polyoxometalate (POM) assemblies (compounds 5-6), in which the POM cores are covalently functionalized by hydrophilic alkyl-chains and enclosed by surfactant of DMDOABr. As a result, we have been able to design and synthesize POM-containing hydrophobic materials beyond surfactant encapsulation. In solid state, scanning electron and transmission electron microscopy (SEM and TEM) studies of the TBA salts of compounds 3 and 4 show highly ordered, uniform, reproducible assemblies with unique segmented rodlike morphology. SEM and TEM studies of the DMDOA salts of compounds 5 and 6 show that they form spherical and sea urchin 3D objects in different solvent systems. In solution, the physical properties of compound 5 and 6 (combination of surfactant-encapsulated cluster (SEC) and surface-grafted cluster (SGC)) show a liquid-to-gel phase transition in pure chloroform below 0 degrees C, which are much lower than other reported SECs. By utilizing light scattering measurements, the nanoparticle size for compounds 5 and 6 were measured at 5 degrees C and 30 degrees C, respectively. Other physical properties including differential scanning calorimetry have been reported.

Novel 1,5-diphenyl-6-substituted 1H-pyrazolo[3,4-d]pyrimidin-4(5H)-ones induced apoptosis in RKO colon cancer cells.

PubMed

Malki, Ahmed; Ashour, Hayam M A; Elbayaa, Rasha Y; Issa, Doaa A E; Aziz, Hassan A; Chen, Xiaozhuo

2016-12-01

Novel 1,5-diphenyl-6-substituted-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-ones were synthesized and characterized. All compounds were screened for their anti-proliferative activities in five different cancer cell lines. The results showed that compounds 7a and 7b comprising aminoguanidino or guanidino moiety at position 6 inhibited proliferation of RKO colon cancer cells with IC50 of 8 and 4 μM, respectively. Compounds 7a and 7b induced apoptosis in RKO cells, which was confirmed by TUNEL and annexin V-FITC assays. Flow cytometric analysis indicated that compounds 7a and 7b arrested RKO cells in the G1 phase and the most active compound 7b increased levels of p53, p21, Bax, ERK1/2 and reduced levels of Bcl2 and Akt. Compound 7b also activates release of cytochrome c, which is consistent with activation of caspase-9. Additionally, compound 7b increased caspase-3 activity and cleaved PARP-1 in RKO cells. Collectively, these findings could establish a molecular basis for the development of new anti-cancer agents.

Oxalato-bridged dinuclear complexes of Cr(III) and Fe(III): synthesis, structure, and magnetism of [(C2H5)4N]4[MM'(ox)(NCS)8] with MM' = CrCr, FeFe, and CrFe.

PubMed

Triki, S; Bérézovsky, F; Sala Pala, J; Coronado, E; Gómez-García, C J; Clemente, J M; Riou, A; Molinié, P

2000-08-21

A new series of homo- and heterometallic oxalato-bridged dinuclear compounds of formulas [Et4N]4[MM'(ox)(NCS)8] ([Et4N]+ = [(C2H5)4N]+; ox = C2O4(2-)) with MM' = Cr(III)-Cr(III) (1), Fe(III)-Fe(III) (2), and Cr(III)-Fe(III) (3) is reported. They have been structurally characterized by infrared spectra and single-crystal X-ray diffraction. The three compounds are isostructural and crystallize in the orthorhombic space group Cmca with Z = 8, a = 16.561(8) A, b = 13.481(7) A, and c = 28.168(8) A for 1, a = 16.515(2) A, b = 13.531(1) A, and c = 28.289(4) A for 2, a = 16.664(7) A, b = 13.575(6) A, and c = 28.386(8) A for 3. The structure of 3 is made up of a discrete dinuclear anion [CrFe(ox)(NCS)8]4- and four disordered [Et4N]+ cations, each of them located on special positions. The anion, in a crystallographically imposed C2h symmetry, contains metal cations in distorted octahedral sites. The Cr(ox)Fe group, which is planar within 0.02 A, presents an intramolecular metal-metal distance of 5.43 A. Magnetic susceptibility measurements indicate antiferromagnetic pairwise interactions for 1 and 2 with J = -3.23 and -3.84 cm-1, respectively, and ferromagnetic Cr-Fe coupling with J = 1.10 cm-1 for 3 (J being the parameter of the exchange Hamiltonian H = -2JS1S2). The ESR spectra at different temperatures confirm the magnetic susceptibility data.

Single‐Molecule Conductance Studies of Organometallic Complexes Bearing 3‐Thienyl Contacting Groups

PubMed Central

Bock, Sören; Al‐Owaedi, Oday A.; Eaves, Samantha G.; Milan, David C.; Lemmer, Mario; Skelton, Brian W.; Osorio, Henrry M.; Nichols, Richard J.; Higgins, Simon J.; Cea, Pilar; Long, Nicholas J.; Albrecht, Tim

2017-01-01

Abstract The compounds and complexes 1,4‐C6H4(C≡C‐cyclo‐3‐C4H3S)2 (2), trans‐[Pt(C≡C‐cyclo‐3‐C4H3S)2(PEt3)2] (3), trans‐[Ru(C≡C‐cyclo‐3‐C4H3S)2(dppe)2] (4; dppe=1,2‐bis(diphenylphosphino)ethane) and trans‐[Ru(C≡C‐cyclo‐3‐C4H3S)2{P(OEt)3}4] (5) featuring the 3‐thienyl moiety as a surface contacting group for gold electrodes have been prepared, crystallographically characterised in the case of 3–5 and studied in metal|molecule|metal junctions by using both scanning tunnelling microscope break‐junction (STM‐BJ) and STM‐I(s) methods (measuring the tunnelling current (I) as a function of distance (s)). The compounds exhibit similar conductance profiles, with a low conductance feature being more readily identified by STM‐I(s) methods, and a higher feature by the STM‐BJ method. The lower conductance feature was further characterised by analysis using an unsupervised, automated multi‐parameter vector classification (MPVC) of the conductance traces. The combination of similarly structured HOMOs and non‐resonant tunnelling mechanism accounts for the remarkably similar conductance values across the chemically distinct members of the family 2–5. PMID:27897344

Synthesis and structure of A4V6[Te2(4+)Te6+]O24 (A = K, Rb)-two new quaternary mixed-valent tellurium oxides.

PubMed

Zhu, Tianxiang; Qin, Jingui; Halasyamani, P Shiv

2011-09-14

Two new mixed-valent tellurium oxides with vanadium(V), A(4)V(6)[Te(2)(4+)Te(6+)]O(24) (A = K and Rb), have been synthesized by hydrothermal and conventional solid state techniques. Their structures were determined by single-crystal X-ray diffraction analysis. These two iso-structural compounds exhibit layered structural topologies consisting of [V(6)Te(3)O(24)](4-) anionic units. In these anionic structural units, a Te(6+)O(6) octahedron is connected to six VO(4) tetrahedra by corner-sharing to generate a [V(6)TeO(24)] unit, and each of these [V(6)TeO(24)] units are interconnected by sharing two Te(4+)O(3) polyhedra to complete the infinite [V(6)Te(3)O(24)](4-) sheets. Infrared spectroscopy, UV-Visible diffuse reflectance spectroscopy, and thermogravimetric analysis were also performed on these two compounds. Crystal data: K(4)V(6)Te(3)O(24), trigonal, space group R ̅3c (No. 167) with a = b = 9.7075(6) Å, c = 42.701(3) Å, V = 3484.9(4) Å(3), and Z = 6; Rb(4)V(6)Te(3)O(24), trigonal, space group R ̅3c (No. 167) with a = b = 9.8399(9) Å, c = 43.012(4) Å, V = 3606.6(6) Å(3), and Z = 6. This journal is © The Royal Society of Chemistry 2011

Investigation of biological effects of some Mannich Bases containing Bis-1,2,4- Triazole.

PubMed

Parlak, A E; Celik, S; Karatepe, M; Turkoglu, S; Alayunt, N O; Dastan, S D; Ulas, M; Sandal, S; Tekin, S; Koparir, M

2016-06-30

In this study, the effects of Mannich bases containing bis-1,2,4-triazole on the levels of in vivo malondialdehyde (MDA) and antioxidant vitamins (A, E, C) were examined in serum, livers and kidneys of rats. DA and vitamin (A, E, C) levels were determined by high performance liquid chromatography (HPLC). Antioxidant effect was investigated by determining the MDA levels in Saccharomyces cerevisiae cells as in vitro. Furthermore, the antitumor effects of compounds were investigated against MCF-7 human breast cancer cells. Interrelations of results among control and compound groups were evaluated using SPSS statistical software package. As a result, some of the compounds showed effective biological activity when compared to control conditions. The test compounds used in this study may be effective for utilization in the selection and design of model compounds for further studies.

[Determination of longistylin A and longistylin C in Cajanus cajan].

PubMed

Wang, Dawu; Xiao, Minxun; Li, Yirong; Shen, Xiaoling; Lu, Yuanyuan; Liu, Kanglun; Li, Zhenghong; Hu, Yingjie

2011-10-01

To establish quality control criteria for medicinal herb Cajanus cajan based on the determination of longistylin A and longistylin C, two bioactive and specific stilbenes of the plant. Longistylin A and longistylin C were obtained from the leaves of C. cajan by silica gel column chromatography and identified as marker compounds of this plant by spectroscopic analysis. A RP-HPLC method was established to determine the two compounds. Longistylin A and longistylin C were well separated on a Thermo BDS Hypersil C18 column (4.6 mm x 250 mm, 5 microm) with a mobile phase methanol-water (8:2), and showed good linearity in the range of 0.00288 - 0.0576 microg and 0.0112 - 0.224 microg, respectively. The average recoveries were 98.9% and 97.2% with RSD of 2.4% and 2.2% for these two compounds, respectively. The established analysis method is simple and accurate, whicn can be used for quality control of C. cajan.

Synthesis, crystal structures, quantum chemical studies and corrosion inhibition potentials of 4-(((4-ethylphenyl)imino)methyl)phenol and (E)-4-((naphthalen-2-ylimino) methyl) phenol Schiff bases

NASA Astrophysics Data System (ADS)

Elemike, Elias E.; Nwankwo, Henry U.; Onwudiwe, Damian C.; Hosten, Eric C.

2017-11-01

Two Schiff base ligands, 4-(((4-ethylphenyl)imino)methyl)phenol (4EMP) and (E)-4-((naphthalen-2-ylimino) methyl) phenol (4NMP) were synthesized by the reaction of 4-hydroxybenzaldehyde with 4-ethylaniline, 4EMP, or naphthalene-2-amine, 4NMP. The compounds were characterized using NMR (1H and 13C), Fourier transform infra-red (FTIR) and mass spectroscopic techniques. The proton NMR identified the OH peaks at 9.73 and 9.77 ppm for 4EMP and 4NMP respectively, while the 13C NMR showed the imine carbons at 172.57 ppm for 4EMP and at 160.89 ppm for 4NMP. The FTIR spectra showed characteristic peaks at 1605 cm-1 (4EMP) and 1600 cm-1 (4NMP) typical of the azomethine group, and the mass spectra results gave molecular ion peaks of 226.12 and 248.10 respectively. The structures of the compounds were further established by single crystal X-ray analysis. The corrosion inhibition potential of the compounds were studied on mild steel surface in a 1 M hydrochloric acid (HCl) solution, and was analysed using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The results of the electrochemical methods showed that the studied molecules imparted high resistance in allowing flow of electrons across the metal-electrolyte platform and behaved as mixed type inhibitors with 4EMP showing better inhibition properties than 4NMP. Scanning electron microscopy (SEM) showed the formation of film on the mild steel surface. Quantum chemical calculations achieved by density functional theory (DFT) was further applied to explain the adsorption as well as inhibition abilities of the molecules on the mild steel surface. Thermodynamics studies showed that the two compounds obeyed the Langmuir isotherm with 4EMP conforming to chemisorption mechanism while 4NMP involved competitive physisorption and chemisorption mechanism.

Three new enantiomerically pure ferrocenylphosphole compounds.

PubMed

López Cortés, José Guadalupe; Vincendeau, Sandrine; Daran, Jean Claude; Manoury, Eric; Gouygou, Maryse

2006-05-01

The absolute configurations of three new enantiomerically pure ferrocenylphosphole compounds, namely (2S,4S,S(Fc))-4-methoxymethyl-2-[2-(9-thioxo-9lambda5-phosphafluoren-9-yl)ferrocenyl]-1,3-dioxane, [Fe(C5H5)(C23H22O3PS)], (III), (S(Fc))-[2-(9-thioxo-9lambda5-phosphafluoren-9-yl)ferrocenyl]methanol, [Fe(C5H5)(C18H14OPS)], (V), and (S(Fc))-diphenyl[2-(9-thioxo-9lambda5-phosphafluoren-9-yl]ferrocenylmethyl]phosphine, [Fe(C5H5)(C30H23P2)], (VIII), have been unambiguously established. All three ligands contain a planar chiral ferrocene group, bearing a dibenzophosphole and either a dioxane, a methanol or a diphenylphosphinomethane group on the same cyclopentadienyl. In compound (V), the occurrence of O-H...S and C-H...S hydrogen bonds results in the formation of a two-dimensional network parallel to (001). The geometry of the ferrocene frameworks agrees with related reported structures.

Syntheses, structures and properties of 3D inorganic-organic hybrid frameworks constructed from lanthanide polymer and Keggin-type tungstosilicate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao Yuanzhe; College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang, Hebei 050016; Xu Yanqing, E-mail: xyq@bit.edu.c

2010-05-15

Inorganic-organic hybrid frameworks, namely [Ce(H{sub 2}O){sub 3}(pdc)]{sub 4}[SiW{sub 12}O{sub 40}].6H{sub 2}O 1, [M(H{sub 2}O){sub 4}(pdc)]{sub 4}[SiW{sub 12}O{sub 40}].2H{sub 2}O (M=Ce for 2a, La for 2b, Nd for 2c; H{sub 2}pdc=pyridine-2,6-dicarboxylic acid) were assembled through incorporation of Keggin-type heteropolyanion [SiW{sub 12}O{sub 40}]{sup 4-} within the voids of lanthanides-pdc network as pillars or guests under hydrothermal condition. Single-crystal X-ray analyses of these crystals reveal that compound 1 presents 3D pillar-layered framework with the [SiW{sub 12}O{sub 40}]{sup 4-} anions located on the square voids of the two-dimensional Ce-pdc bilayer. Compounds 2a-c are isostructural and constructed from 3D Ln-pdc-based metal-organic framework (MOF) incorporating noncoordinatingmore » guests Keggin structure [SiW{sub 12}O{sub 40}]{sup 4-}. Solid-state properties of compounds 1 and 2a-c such as thermal stability and photoluminescence have been further investigated. - Graphical abstract: Two types of new inorganic-organic hybrid frameworks through incorporation of Keggin-type heteropolyanion [SiW{sub 12}O{sub 40}]{sup 4-} within the voids of lanthanides-pdc network as pillars or guests under hydrothermal condition were successfully assembled. Solid-state properties of compounds 1 and 2a such as thermal stability and photoluminescence have been further investigated.« less

Synthesis, biological assessment and molecular modeling of new dihydroquinoline-3-carboxamides and dihydroquinoline-3-carbohydrazide derivatives as cholinesterase inhibitors, and Ca channel antagonists.

PubMed

Tomassoli, Isabelle; Ismaili, Lhassane; Pudlo, Marc; de Los Ríos, Cristóbal; Soriano, Elena; Colmena, Inés; Gandía, Luis; Rivas, Luis; Samadi, Abdelouahid; Marco-Contelles, José; Refouvelet, Bernard

2011-01-01

The synthesis, biological evaluation, and molecular modeling of new 4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxamides(4), 4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carbohydrazide (6), and some hexahydropyrimido[5,4-c]quinoline-2,5-diones (9) produced earlier by our laboratory, as AChE/BuChE inhibitors, is described. From these analyses compound 4c resulted equipotent regarding the inhibition of cholinesterases'; inhibitors 6k, 9a, 9b were selective for AChE, whereas product 4d proved selective for BuChE. Docking analysis has been carry out in order to identify the binding mode in the active site, and to explain the observed selectivities. Only compound 9a has been shown to decrease K(+)-induced calcium signals in bovine chromaffin cells. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Electronic properties and structural phase transition in A4 [M4O4] (A=Li, Na, K and Rb; M=Ag and Cu): A first principles study

NASA Astrophysics Data System (ADS)

Umamaheswari, R.; Yogeswari, M.; Kalpana, G.

2013-02-01

Self-consistent scalar relativistic band structure calculations for AMO (A=Li, Na, K and Rb; M=Ag and Cu) compounds have been performed using the tight-binding linear muffin-tin orbital (TB-LMTO) method within the local density approximation (LDA). At ambient conditions, these compounds are found to crystallize in tetragonal KAgO-type structure with two different space group I-4m2 and I4/mmm. Nowadays, hypothetical structures are being considered to look for new functional materials. AMO compounds have stoichiometry similar to eight-electron half-Heusler materials of type I-I-VI which crystallizes in cubic (C1b) MgAgAs-type structure with space group F-43m. For all these compounds, by interchanging the positions of atoms in the hypothetical cubic structure, three phases (α, β and γ) are formed. The energy-volume relation for these compounds in tetragonal KAgO-type structure and cubic α, β and γ phases of related structure have been obtained. Under ambient conditions these compounds are more stable in tetragonal KAgO-type (I4/mmm) structure. The total energies calculated within the atomic sphere approximation (ASA) were used to determine the ground state properties such as equilibrium lattice parameters, c/a ratio, bulk modulus, cohesive energy and are compared with the available experimental results. The results of the electronic band structure calculations at ambient condition show that LiCuO and NaMO are indirect band gap semiconductors whereas KMO and RbMO are direct band gap semiconductors. At high pressure the band gap decreases and the phenomenon of band overlap metallization occur. Also these compounds undergo structural phase transition from tetragonal I-4m2 phase to cubic α-phase and transition pressures were calculated.

Hydrogenation of Organic Matter as a Terminal Electron Sink Sustains High CO 2 :CH 4 Production Ratios During Anaerobic Decomposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, Rachel M.; Tfaily, Malak M.; Rich, Virginia I.

Once inorganic electron acceptors are depleted, organic matter in anoxic environments decomposes by hydrolysis, fermentation, and methanogenesis, requiring syntrophic interactions between microorganisms to achieve energetic favorability. In this classic anaerobic food chain, methanogenesis represents the terminal electron accepting (TEA) process, ultimately producing equimolar CO 2 and CH 4 for each molecule of organic matter degraded. However, CO 2:CH 4 production in Sphagnum-derived, mineral-poor, cellulosic peat often substantially exceeds this 1:1 ratio, even in the absence of measureable inorganic TEAs. Since the oxidation state of C in both cellulose-derived organic matter and acetate is 0, and CO 2 has an oxidationmore » state of +4, if CH 4 (oxidation state -4) is not produced in equal ratio, then some other compound(s) must balance CO 2 production by receiving 4 electrons. Here we present evidence for ubiquitous hydrogenation of diverse unsaturated compounds that appear to serve as organic TEAs in peat, thereby providing the necessary electron balance to sustain CO 2:CH 4 >1. While organic electron acceptors have previously been proposed to drive microbial respiration of organic matter through the reversible reduction of quinone moieties, the hydrogenation mechanism that we propose, by contrast, reduces C-C double bonds in organic matter thereby serving as 1) a terminal electron sink, 2) a mechanism for degrading complex unsaturated organic molecules, 3) a potential mechanism to regenerate electron-accepting quinones, and, in some cases, 4) a means to alleviate the toxicity of unsaturated aromatic acids. In conclusion, this mechanism for CO 2 generation without concomitant CH 4 production has the potential to regulate the global warming potential of peatlands by elevating CO 2:CH 4 production ratios.« less

Hydrogenation of Organic Matter as a Terminal Electron Sink Sustains High CO 2 :CH 4 Production Ratios During Anaerobic Decomposition

DOE PAGES

Wilson, Rachel M.; Tfaily, Malak M.; Rich, Virginia I.; ...

2017-07-03

Once inorganic electron acceptors are depleted, organic matter in anoxic environments decomposes by hydrolysis, fermentation, and methanogenesis, requiring syntrophic interactions between microorganisms to achieve energetic favorability. In this classic anaerobic food chain, methanogenesis represents the terminal electron accepting (TEA) process, ultimately producing equimolar CO 2 and CH 4 for each molecule of organic matter degraded. However, CO 2:CH 4 production in Sphagnum-derived, mineral-poor, cellulosic peat often substantially exceeds this 1:1 ratio, even in the absence of measureable inorganic TEAs. Since the oxidation state of C in both cellulose-derived organic matter and acetate is 0, and CO 2 has an oxidationmore » state of +4, if CH 4 (oxidation state -4) is not produced in equal ratio, then some other compound(s) must balance CO 2 production by receiving 4 electrons. Here we present evidence for ubiquitous hydrogenation of diverse unsaturated compounds that appear to serve as organic TEAs in peat, thereby providing the necessary electron balance to sustain CO 2:CH 4 >1. While organic electron acceptors have previously been proposed to drive microbial respiration of organic matter through the reversible reduction of quinone moieties, the hydrogenation mechanism that we propose, by contrast, reduces C-C double bonds in organic matter thereby serving as 1) a terminal electron sink, 2) a mechanism for degrading complex unsaturated organic molecules, 3) a potential mechanism to regenerate electron-accepting quinones, and, in some cases, 4) a means to alleviate the toxicity of unsaturated aromatic acids. In conclusion, this mechanism for CO 2 generation without concomitant CH 4 production has the potential to regulate the global warming potential of peatlands by elevating CO 2:CH 4 production ratios.« less

Hydrogenation of organic matter as a terminal electron sink sustains high CO 2 :CH 4 production ratios during anaerobic decomposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, Rachel M.; Tfaily, Malak M.; Rich, Virginia I.

Once inorganic electron acceptors are depleted, organic matter in anoxic environments decomposes by hydrolysis, fermentation, and methanogenesis, requiring syntrophic interactions between microorganisms to achieve energetic favorability. In this classic anaerobic food chain, methanogenesis represents the terminal electron accepting (TEA) process, ultimately producing equimolar CO2 and CH4 for each molecule of organic matter degraded. However, CO2:CH4 production in Sphagnum-derived, mineral-poor, cellulosic peat often substantially exceeds this 1:1 ratio, even in the absence of measureable inorganic TEAs. Since the oxidation state of C in both cellulose-derived organic matter and acetate is 0, and CO2 has an oxidation state of +4, if CH4more » (oxidation state -4) is not produced in equal ratio, then some other compound(s) must balance CO2 production by receiving 4 electrons. Here we present evidence for ubiquitous hydrogenation of diverse unsaturated compounds that appear to serve as organic TEAs in peat, thereby providing the necessary electron balance to sustain CO2:CH4 >1. While organic electron acceptors have previously been proposed to drive microbial respiration of organic matter through the reversible reduction of quinone moieties, the hydrogenation mechanism that we propose, by contrast, reduces C-C double bonds in organic matter thereby serving as 1) a terminal electron sink, 2) a mechanism for degrading complex unsaturated organic molecules, 3) a potential mechanism to regenerate electron-accepting quinones, and, in some cases, 4) a means to alleviate the toxicity of unsaturated aromatic acids. This mechanism for CO2 generation without concomitant CH4 production has the potential to regulate the global warming potential of peatlands by elevating CO2:CH4 production ratios.« less

Constituents of Musa x paradisiaca cultivar with the potential to induce the phase II enzyme, quinone reductase.

PubMed

Jang, Dae Sik; Park, Eun Jung; Hawthorne, Michael E; Vigo, Jose Schunke; Graham, James G; Cabieses, Fernando; Santarsiero, Bernard D; Mesecar, Andrew D; Fong, Harry H S; Mehta, Rajendra G; Pezzuto, John M; Kinghorn, A Douglas

2002-10-23

A new bicyclic diarylheptanoid, rel-(3S,4aR,10bR)-8-hydroxy-3-(4-hydroxyphenyl)-9-methoxy-4a,5,6,10b-tetrahydro-3H-naphtho[2,1-b]pyran (1), as well as four known compounds, 1,2-dihydro-1,2,3-trihydroxy-9-(4-methoxyphenyl)phenalene (2), hydroxyanigorufone (3), 2-(4-hydroxyphenyl)naphthalic anhydride (4), and 1,7-bis(4-hydroxyphenyl)hepta-4(E),6(E)-dien-3-one (5), were isolated from an ethyl acetate-soluble fraction of the methanol extract of the fruits of Musa x paradisiaca cultivar, using a bioassay based on the induction of quinone reductase (QR) in cultured Hepa1c1c7 mouse hepatoma cells to monitor chromatographic fractionation. The structure and relative stereochemistry of compound 1 were elucidated unambiguously by one- and two-dimensional NMR experiments ((1)H NMR, (13)C NMR, DEPT, COSY, HMQC, HMBC, and NOESY) and single-crystal X-ray diffraction analysis. Isolates 1-5 were evaluated for their potential cancer chemopreventive properties utilizing an in vitro assay to determine quinone reductase induction and a mouse mammary organ culture assay.

On the structural and luminescent properties of the M'LnTaO/sub 4/ rare earth tantalates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brixner, L.H.; Chen, H.-Y.

1983-12-01

The structure of M YTaO/sub 4/ has been redetermined and was refined to an R value of 0.034. M'YTaO/sub 4/ crystallizes in P2/a symmetry with a = 5.298(1),b = 5.451(1),c = 5.111(1)A,..beta.. = 96.45 deg. At temperatures > 1450/sup 0/C,M'YTaO/sub 4/ will convert by way of a reconstructive transformation into the I4/sub 1//a symmetry of scheelite, and, upon cooling, a second-order ferroelastic transition (4/mF2/m) to M (fergusonite) YTaO/sub 4/ occurs. There are significant structural differences between M and M'YTaO/sub 4/ which are discussed. M'LnTaO/sub 4/ compounds exist from Ln = Sm to Lu. As a host for luminescent ions, M'YTaO/submore » 4/ is superior to the M modification, as well as all other compounds in the Y/sub 2/O/sub 2/Ta/sub 2/O/sub 5/ phase diagram.« less

1,4-Dihydropyridines Active on the SIRT1/AMPK Pathway Ameliorate Skin Repair and Mitochondrial Function and Exhibit Inhibition of Proliferation in Cancer Cells.

PubMed

Valente, Sergio; Mellini, Paolo; Spallotta, Francesco; Carafa, Vincenzo; Nebbioso, Angela; Polletta, Lucia; Carnevale, Ilaria; Saladini, Serena; Trisciuoglio, Daniela; Gabellini, Chiara; Tardugno, Maria; Zwergel, Clemens; Cencioni, Chiara; Atlante, Sandra; Moniot, Sébastien; Steegborn, Clemens; Budriesi, Roberta; Tafani, Marco; Del Bufalo, Donatella; Altucci, Lucia; Gaetano, Carlo; Mai, Antonello

2016-02-25

Modulators of sirtuins are considered promising therapeutic targets for the treatment of cancer, cardiovascular, metabolic, inflammatory, and neurodegenerative diseases. Here we prepared new 1,4-dihydropyridines (DHPs) bearing changes at the C2/C6, C3/C5, C4, or N1 position. Tested with the SIRTainty procedure, some of them displayed increased SIRT1 activation with respect to the prototype 3a, high NO release in HaCat cells, and ameliorated skin repair in a mouse model of wound healing. In C2C12 myoblasts, two of them improved mitochondrial density and functions. All the effects were reverted by coadministration of compound C (9), an AMPK inhibitor, or of EX-527 (10), a SIRT1 inhibitor, highlighting the involvement of the SIRT1/AMPK pathway in the action of DHPs. Finally, tested in a panel of cancer cells, the water-soluble form of 3a, compound 8, displayed antiproliferative effects in the range of 8-35 μM and increased H4K16 deacetylation, suggesting a possible role for SIRT1 activators in cancer therapy.

Pentavalent and tetravalent uranium selenides, Tl3Cu4USe6 and Tl2Ag2USe4: syntheses, characterization, and structural comparison to other layered actinide chalcogenide compounds.

PubMed

Bugaris, Daniel E; Choi, Eun Sang; Copping, Roy; Glans, Per-Anders; Minasian, Stefan G; Tyliszczak, Tolek; Kozimor, Stosh A; Shuh, David K; Ibers, James A

2011-07-18

The compounds Tl(3)Cu(4)USe(6) and Tl(2)Ag(2)USe(4) were synthesized by the reaction of the elements in excess TlCl at 1123 K. Both compounds crystallize in new structure types, in space groups P2(1)/c and C2/m, respectively, of the monoclinic system. Each compound contains layers of USe(6) octahedra and MSe(4) (M = Cu, Ag) tetrahedra, separated by Tl(+) cations. The packing of the octahedra and the tetrahedra within the layers is compared to the packing arrangements found in other layered actinide chalcogenides. Tl(3)Cu(4)USe(6) displays peaks in its magnetic susceptibility at 5 and 70 K. It exhibits modified Curie-Weiss paramagnetic behavior with an effective magnetic moment of 1.58(1) μ(B) in the temperature range 72-300 K, whereas Tl(2)Ag(2)USe(4) exhibits modified Curie-Weiss paramagnetic behavior with μ(eff) = 3.4(1) μ(B) in the temperature range 100-300 K. X-ray absorption near-edge structure (XANES) results from scanning transmission X-ray spectromicroscopy confirm that Tl(3)Cu(4)USe(6) has Se bonding characteristic of discrete Se(2-) units, Cu bonding generally representative of Cu(+), and U bonding consistent with a U(4+) or U(5+) species. On the basis of these measurements, as well as bonding arguments, the formal oxidation states for U may be assigned as +5 in Tl(3)Cu(4)USe(6) and +4 in Tl(2)Ag(2)USe(4).

Synthesis of [1-.sup.13C]pyruvic acid], [2-.sup.13C]pyruvic acid], [3-.sup.13C]pyruvic acid] and combinations thereof

DOEpatents

Martinez, Rodolfo A. , Unkefer; Clifford J. , Alvarez; Marc, A [Santa Fe, NM

2012-06-12

The present invention is directed to the labeled compounds, ##STR00001## wherein C* is each either .sup.13C and .sup.12C where at least one C* is .sup.13C, each hydrogen of the methylene group is hydrogen or deuterium, the methyl group includes either zero or three deuterium atoms, Q is sulfide, sulfinyl, or sulfone, Z is an aryl group such as 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, or a phenyl group ##STR00002## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each independently either hydrogen, a C.sub.1-C.sub.4 lower alkyl, a halogen, and an amino group such as NH.sub.2, NHR and NRR' where R and R' are each independently either a C.sub.1-C.sub.4 lower alkyl, a phenyl, and an alkoxy group, and the methyl group can include either zero or three deuterium atoms. The present invention is also directed to the labeled compounds ##STR00003##

Preparation, structure and luminescent characterization of a series of metal-organic frameworks based on flexible ligands with nitrogen heterocycles and carboxyl

NASA Astrophysics Data System (ADS)

Dai, Hai-yu; Tang, Yu-yuan; Wang, Cui-juan; Chen, Shuang; Tong, Yan; Zhang, Zhi-Bing

2017-12-01

Seven new compounds, [Zn(pypymba)2]n(1), [Co(pypymba)2]n(2), [Cd(pypymba)2]n(3), [Cd(Hpypymba)Cl2]n(4), {[Cd(pypymba)Cl]·C2H5OH·H2O}n(5), [Cd(pypyaa)Cl]n(6), {[Cd2(pyznpy)2Cl2H2O]·H2O}n(7) [Hpypymba = 4-((3-(pyrazin-2-yl)-1H-pyrazol-1-yl)methyl)benzoic acid, Hpyznpy = 4-((3-(pyridin-2-yl)-1H-pyrazol-1-yl)methyl)benzoic acid, Hpypyaa = 2-(3-pyridin-2-yl)-1H-pyrazol-1-yl)acetic acid], were hydrothermally synthesized by tuning the metal ion's species, counter anions, solvents and pH values and characterized by routine methods: XRD, elemental analysis, fluorescence properties analysis, TGA and crystal structure analysis and single-crystal X-ray crystallography. The main structures of the compounds 1, 2, and 3 are extended to similar 3D structures by C-H…N, C-H…O hydrogen bonds and π…π stacking under the same synthesis method. Each Cd(II) node of compound 4 has four chlorine bridges (two pairs of double chlorine); Each Cd(II) node of compounds 5, 6 has two chlorine bridges (a pair of double chlorine bridges), while their spatial structures are expanded in different ways. Compound 7 also contains chlorine atoms, but does not contain chlorine bridged structures. The luminescent properties of compound 7 and the ones immersed in various kinds of organic compounds and nitrate@EtOH solutions have been investigated. Importantly, 7 shows highly sensitive response to nitrobenzene and Fe3+ through luminescence quenching effects, making it a promising luminescent sensor for nitrobenzene and Fe3+.

Investigating the Structural, Thermal, and Electronic Properties of the Zircon-Type ZrSiO4, ZrGeO4 and HfSiO4 Compounds

NASA Astrophysics Data System (ADS)

Chiker, Fafa; Boukabrine, Fatiha; Khachai, H.; Khenata, R.; Mathieu, C.; Bin Omran, S.; Syrotyuk, S. V.; Ahmed, W. K.; Murtaza, G.

2016-11-01

In the present study, the structural, thermal, and electronic properties of some important orthosilicate dielectrics, such as the ZrSiO4, ZrGeO4, and HfSiO4 compounds, have been investigated theoretically with the use of first-principle calculations. We attribute the application of the modified Becke-Johnson exchange potential, which is basically an improvement over the local density approximation and the Perdew-Burke-Ernzerhof exchange-correlation functional, for a better description of the band gaps of the compounds. This resulted in a good agreement with our estimated values in comparison with the reported experimental data, specifically for the ZrSiO4, and HfSiO4 compounds. Conversely, for the ZrGeO4 compound, the calculated electronic band structure shows a direct band gap at the Γ point with the value of 5.79 eV. Furthermore, our evaluated thermal properties that are calculated by using the quasi-harmonic Debye model indicated that the volume variation with temperature is higher in the ZrGeO4 compound as compared to both the ZrSiO4 and HfSiO4 compounds, which is ascribed to the difference between the electron shells of the Si and Ge atoms. Therefore, these results also indicate that while the entropy ( S) and enthalpy ( U) parameters increase monotonically, the free energy ( G), in contrast, decreases monotonically with increasing temperature, respectively. Moreover, the pressure and temperature dependencies of the Debye temperature Θ, thermal expansion coefficient, and heat capacities C V were also predicted in our study.

Design, synthesis, and antiviral activity of novel rutin derivatives containing 1, 4-pentadien-3-one moiety.

PubMed

Han, Yu; Ding, Yan; Xie, Dandan; Hu, Deyu; Li, Pei; Li, Xiangyang; Xue, Wei; Jin, Linhong; Song, Baoan

2015-03-06

Rutin (compound 5) and some compounds (compounds 1-4 and 6) were isolated from Artemisia princeps Pamp (A. princeps Pamp.) and a series of novel rutin derivatives containing 1,4-pentadien-3-one moiety were designed and synthesized. The target compounds were characterized by proton nuclear magnetic resonance spectroscopy ((1)H NMR), carbon nuclear magnetic resonance spectroscopy ((13)C NMR), and ESI-MS. Bioassay results indicated that some of the compounds showed good to excellent antiviral activities against tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV) at 500 μg/mL in vivo. The 50% effective concentrations (EC50) of the compound 7r against CMV was 394.78 μg/mL, which was better than that of Ningnanmycin (432.22 μg/mL). These results indicated that novel rutin derivatives containing 1,4-pentadien-3-one moiety can effectively control CMV. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Antifungal dimeric chalcone derivative kamalachalcone E from Mallotus philippinensis.

PubMed

Kulkarni, Roshan R; Tupe, Santosh G; Gample, Suwarna P; Chandgude, Macchindra G; Sarkar, Dhiman; Deshpande, Mukund V; Joshi, Swati P

2014-01-01

From the red coloured extract (Kamala) prepared through acetone extraction of the fresh whole uncrushed fruits of Mallotus philippinensis, one new dimeric chalcone (1) along with three known compounds 1-(5,7-dihydroxy-2,2,6-trimethyl-2H-1-benzopyran-8-yl)-3-phenyl-2-propen-1-one (2), rottlerin (3) and 4'-hydroxyrottlerin (4) were isolated. The structure of compound 1 was elucidated by 1D and 2D NMR analyses that included HSQC, HMBC, COSY and ROESY experiments along with the literature comparison. Compounds 1-4 were evaluated for antifungal activity against different human pathogenic yeasts and filamentous fungi. The antiproliferative activity of the compounds was evaluated against Thp-1 cell lines. Compounds 1 and 2 both exhibited IC50 of 8, 4 and 16 μg/mL against Cryptococcus neoformans PRL518, C. neoformans ATCC32045 and Aspergillus fumigatus, respectively. Compound 4, at 100 μg/mL, showed 54% growth inhibition of Thp-1 cell lines.

Design, Synthesis, in Vitro, and in Vivo Anticancer and Antiangiogenic Activity of Novel 3-Arylaminobenzofuran Derivatives Targeting the Colchicine Site on Tubulin

PubMed Central

Romagnoli, Romeo; Baraldi, Pier Giovanni; Salvador, Maria Kimatrai; Prencipe, Filippo; Lopez-Cara, Carlota; Ortega, Santiago Schiaffino; Brancale, Andrea; Hamel, Ernest; Castagliuolo, Ignazio; Mitola, Stefania; Ronca, Roberto; Bortolozzi, Roberta; Porcù, Elena; Basso, Giuseppe; Viola, Giampietro

2015-01-01

A new series of compounds characterized by the presence of a 2-methoxy/ethoxycarbonyl group, combined with either no substituent or a methoxy group at each of the four possible positions of the benzene portion of the 3-(3′,4′,5′-trimethoxyanilino)benzo[b]furan skeleton, were evaluated for antiproliferative activity against cancer cells in culture and, for selected, highly active compounds, inhibition of tubulin polymerization, cell cycle effects, and in vivo potency. The greatest antiproliferative activity occurred with a methoxy group introduced at the C-6 position, the least with this substituent at C-4. Thus far, the most promising compound in this series was 2-methoxycarbonyl-3-(3′,4′,5′-trimethoxyanilino)-6-methoxybenzo-[b]furan (3g), which inhibited cancer cell growth at nanomolar concentrations (IC50 values of 0.3–27 nM), bound to the colchicine site of tubulin, induced apoptosis, and showed, both in vitro and in vivo, potent vascular disrupting properties derived from the effect of this compound on vascular endothelial cells. Compound 3g had in vivo antitumor activity in a murine model comparable to the activity obtained with combretastatin A-4 phosphate. PMID:25785605

Compositions of the volatile oils of Citrus macroptera and C. maxima.

PubMed

Rana, Virendra S; Blazquez, Maria A

2012-10-01

The essential oils obtained by hydrodistillation from the fresh peels of Citrus macroptera Montr. and C. maxima (Burm.) Merr. were analyzed by GC and GC/MS. The yields of oil ranged from 0.53% in C. macroptera to 0.13% in C. maxima cultivar (white). Forty-seven compounds were identified in the oils with limonene (55.3-80.0%), dodecyl acrylate (2.2-8.0%), geranial (0.4-3.5%), trans-linalool oxide (1.0-2.8%), alpha-terpineol (0.7-2.3%), linalool (0.7-1.5%) and cis-linalool oxide (0.5-1.4%) identified as major compounds. The oil ofC. macroptera contained limonene (55.3%), beta-caryophyllene (4.7%) and geranial (3.5%) as main compounds. Similarly, oils from two C. maxima (pink and white) cultivars were rich in limonene (72.0-80.0%), dodecyl acrylate (8.0-7.2%) and nootkatone (1.6-2.5%). C. maxima (pink and white) cultivars were found to contain higher amount of limonene (72.0 and 80.0%) as compared with C. macroptera (55.3%). The chemical compositions of the oils were found to be similar, but nootkatone (1.6-2.5%) was identified only in C. maxima cultivars.

Synthesis, X-ray Single Crystal Structure, Molecular Docking and DFT Computations on N-[(1E)-1-(2H-1,3-Benzodioxol-5-yl)-3-(1H-imidazol-1-yl)propylidene]-hydroxylamine: A New Potential Antifungal Agent Precursor.

PubMed

Al-Wabli, Reem I; Al-Ghamdi, Alwah R; Ghabbour, Hazem A; Al-Agamy, Mohamed H; Monicka, James Clemy; Joe, Issac Hubert; Attia, Mohamed I

2017-02-28

Mycoses are serious health problem, especially in immunocompromised individuals. A new imidazole-bearing compound containing an oxime functionality was synthesized and characterized with different spectroscopic techniques to be used for the preparation of new antifungal agents. The stereochemistry of the oxime double bond was unequivocally determined via the single crystal X-ray technique. The title compound 4 , C 13 H 13 N₃O₃·C₃H₈O, crystallizes in the monoclinic space group P 2₁with a = 9.0963(3) Å, b = 14.7244(6) Å, c = 10.7035(4) Å, β = 94.298 (3)°, V = 1429.57(9) ų, Z = 2. The molecules were packed in the crystal structure by eight intermolecular hydrogen bond interactions. A comprehensive spectral analysis of the title molecule 4 has been performed based on the scaled quantum mechanical (SQM) force field obtained by density-functional theory (DFT) calculations. A molecular docking study illustrated the binding mode of the title compound 4 into its target protein. The preliminary antifungal activity of the title compound 4 was determined using a broth microdilution assay.

An antibacterial ortho-quinone diterpenoid and its derivatives from Caryopteris mongolica.

PubMed

Saruul, Erdenebileg; Murata, Toshihiro; Selenge, Erdenechimeg; Sasaki, Kenroh; Yoshizaki, Fumihiko; Batkhuu, Javzan

2015-06-15

To identify antibacterial components in traditional Mongolian medicinal plant Caryopteris mongolica, an ortho-quinone abietane caryopteron A (1) and three its derivatives caryopteron B-D (2-4) were isolated from the roots of the plant together with three known abietanes demethylcryptojaponol (5), 6α-hydroxydemethyl cryptojaponol (6), and 14-deoxycoleon U (7). The chemical structures of these abietane derivatives were elucidated on the basis of spectroscopic data. Compounds 1-4 had C-13 methylcyclopropane substructures, and 2-4 had a hexanedioic anhydride ring C instead of ortho-quinone in 1. The stereochemistry of these compound was assumed from NOE spectra and ECD Cotton effects. Compounds 1 and 5-7 showed antibacterial activities against the Gram-positive bacteria Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, and Micrococcus luteus, being 1 the more potent. Copyright © 2015 Elsevier Ltd. All rights reserved.

Active compound diffusivity of particle size reduced S. aromaticum and C. cassia fused starch edible films and the shelf life of mutton (Capra aegagrus hircus) meat.

PubMed

Chandra Mohan, C; Radha Krishnan, K; Babuskin, S; Sudharsan, K; Aafrin, Vajiha; Lalitha Priya, U; Mariyajenita, P; Harini, K; Madhushalini, D; Sukumar, M

2017-06-01

In the present study, mathematical models were used to examine the effect of active compound diffusion from edible film (supplemented with S. aromaticum and C. cassia) on the microbial, physical and chemical quality of mutton stored at 4 and 10°C. Cinnamaldehyde and eugenol release from edible film into liquid was found to be 80% and 75% of the equilibrium concentration. Active compound release into meat was 42-51% for cinnamaldehyde and 38-48% for eugenol, in storage temperatures of 4-15°C. Developed mathematical models showed the diffusivity of cinnamaldehyde (0.45×10 -15 ±0.04×10 -15 ) and eugenol (0.63×10 -10 ±0.01×10 -10 ) into meat, which was about 40% of that in liquid medium. On comparing physical, chemical and microbial results, shelf life of mutton meat was found to be increased by 1week at storage temperature of 10°C and 3weeks at storage temperature of 4°C. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis and isomerization of acridine substituted 1,3-thiazolidin-4-ones and 4-oxo-1,3-thiazolidin-5-ylidene acetates. An experimental and computational study

NASA Astrophysics Data System (ADS)

Bečka, Michal; Vilková, Mária; Šoral, Michal; Potočňák, Ivan; Breza, Martin; Béres, Tibor; Imrich, Ján

2018-02-01

Acridine thiosemicarbazones 3a-g, obtained through a two-step reaction between aromatic isothiocyanates and hydrazine followed by the treatment with acridin-9-carbaldehyde, in reaction with bifunctional reagents; methyl bromoacetate (MBA) and diethyl acetylenedicarboxylate (DEAD) afforded acridin-thiazolidinone derivatives 4a-g and 7a-f and not their regioisomers 6a-g and 9a-f. Derivatives 4a-g and 7a-f exhibit ZC2N6EN7C8 configuration. Upon standing in DMSO-d6 the thiazolidinones 4a-g and 7a-f spontaneously isomerized into ZC2N6ZN7C8 isomers 5a-g and 8a-f to give a mixture of the both stereoisomers. All compounds were fully characterized by multinuclear NMR, mass spectrometry (MS) and X-ray crystal structure of 4b is also described. X-ray diffraction study revealed that the representative compound 4b crystallized in the monoclinic crystal system with the C2/c space group and Z = 4. Intramolecular C1‧sbnd H1‧⋯N-7 hydrogen bond between the acridine proton H-1‧ and nitrogen N-7 of linker existed. This hydrogen bond is responsible for the E isomerism on C-8 atom which was observed in the NMR experiments. Quantum-chemical calculations and NOESY experiments confirmed ZC2N6ZN7C8 configuration of the transformed stereoisomers 5a-g and 8a-f.

Kinetics of acid-catalyzed cleavage of procyanindins

Treesearch

Richard W. Hemingway; Gerald W. McGraw

1983-01-01

Comparison of the rates of cleavage of isomeric procyanidin dimers in the presence of excess phenylmethane thiol and acetic acid showed that compounds with a C(4)-C(8) interflavanoid bond were cleaved more rapidly than their C(4)-C(6) linked isomers, that 2,3-cis isomers with an axial flavan substituent were cleaved more-rapidly than a 2,3-...

Genotoxicity risk assessment of diversely substituted quinolines using the SOS chromotest.

PubMed

Duran, Leidy Tatiana Díaz; Rincón, Nathalia Olivar; Galvis, Carlos Eduardo Puerto; Kouznetsov, Vladimir V; Lorenzo, Jorge Luis Fuentes

2015-03-01

Quinolines are aromatic nitrogen compounds with wide therapeutic potential to treat parasitic and microbial diseases. In this study, the genotoxicity of quinoline, 4-methylquinoline, 4-nitroquinoline-1-oxide (4-NQO), and diversely functionalized quinoline derivatives and the influence of the substituents (functional groups and/or atoms) on their genotoxicity were tested using the SOS chromotest. Quinoline derivatives that induce genotoxicity by the formation of an enamine epoxide structure did not induce the SOS response in Escherichia coli PQ37 cells, with the exception of 4-methylquinoline that was weakly genotoxic. The chemical nature of the substitution (C-5 to C-8: hydroxyl, nitro, methyl, isopropyl, chlorine, fluorine, and iodine atoms; C-2: phenyl and 3,4-methylenedioxyphenyl rings) of quinoline skeleton did not significantly modify compound genotoxicities; however, C-2 substitution with α-, β-, or γ-pyridinyl groups removed 4-methylquinoline genotoxicity. On the other hand, 4-NQO derivatives whose genotoxic mechanism involves reduction of the C-4 nitro group were strong inducers of the SOS response. Methyl and nitrophenyl substituents at C-2 of 4-NQO core affected the genotoxic potency of this molecule. The relevance of these results is discussed in relation to the potential use of the substituted quinolines. The work showed the sensitivity of SOS chromotest for studying structure-genotoxicity relationships and bioassay-guided quinoline synthesis. © 2013 Wiley Periodicals, Inc.

β-Lactam Ring Opening: A Useful Entry to Amino Acids and Relevant Nitrogen-Containing Compounds

NASA Astrophysics Data System (ADS)

Palomo, C.; Oiarbide, M.

The main strategies for the ring opening of β-lactams by chemical means are described. The discovery of each approach is put into context, sometimes in connection to processes occurring in biological systems, and the synthetic opportunities each approach offers are shown. Thus, this β-lactam route affords a number of synthetically relevant building-blocks, including α-amino acids, β-amino acids, their derived peptides, and other nitrogen containing heterocycles and open chain molecules. The content, which encompases references to initial work, further major development, and the most relevant recent literature contributions, is categorized according to the ring bond cleavaged (N 1-C 2, C 2-C 3, C 3 -C 4 , N 1-C 4), to finish with ring opening strategies leading to large heterocyclic compounds. Within each category, distinction has been made according to the type of nucleophilic agent employed, principally O-, N-, and C-nucleophiles. Also, a variety of applications of the strategy to the synthesis of interesting target compounds are shown.

Penialidins A-C with strong antibacterial activities from Penicillium sp., an endophytic fungus harboring leaves of Garcinia nobilis.

PubMed

Jouda, Jean-Bosco; Kusari, Souvik; Lamshöft, Marc; Mouafo Talontsi, Ferdinand; Douala Meli, Clovis; Wandji, Jean; Spiteller, Michael

2014-10-01

Three new polyketides named penialidins A-C (1-3), along with one known compound, citromycetin (4), were isolated from an endophytic fungus, Penicillium sp., harbored in the leaves of the Cameroonian medicinal plant Garcinia nobilis. Their structures were elucidated by means of spectroscopic and spectrometric methods (NMR and HRMS(n)). The antibacterial efficacies of the new compounds (1-3) were tested against the clinically-important risk group 2 (RG2) bacterial strains of Staphylococcus aureus and Escherichia coli. The ecologically imposing strains of E. coli (RG1), Bacillus subtilis and Acinetobacter sp. BD4 were also included in the assay. Compound 3 exhibited pronounced activity against the clinically-relevant S. aureus as well as against B. subtilis comparable to that of the reference standard (streptomycin). Compound 2 was also highly-active against S. aureus. By comparing the structures of the three new compounds (1-3), it was revealed that altering the substitutions at C-10 and C-2 can significantly increase the antibacterial activity of 1. Copyright © 2014 Elsevier B.V. All rights reserved.

The antioxidant effect of derivatives pyroglutamic lactam

NASA Astrophysics Data System (ADS)

Rohadi, Atisya; Lazim, Azwani Mat; Hasbullah, Siti Aishah

2013-11-01

Diphenylpicrylhydrazyl (DPPH) is widely used for quickly accessing the ability of polyphenols to transfer labile H atoms to radicals. The antioxidant activity of all the synthesized compounds was screened by DPPH method. Compound (4) showed 54% antioxidant potential while all other compounds were found to have moderate to have moderate to mild antioxidant activity ranging from 47-52%. Pyroglutamic lactams have been synthesized stereoselectively in racemic form from levulinic acid as bifunctional adduct using convertible isocyanide in one-pot Ugi 4-center-3-component condensation reaction (U-4C-3CR). The product formed provides biologically interesting products in excellent yields in a short reaction time. The structures of the synthesized compounds were elucidated using spectroscopic data and elemental analysis.

Molecular association of 2-(n-alkylamino)-1,4-naphthoquinone derivatives: Electrochemical, DFT studies and antiproliferative activity against leukemia cell lines

NASA Astrophysics Data System (ADS)

Patil, Rishikesh; Bhand, Sujit; Konkimalla, V. Badireenath; Banerjee, Priyabrata; Ugale, Bharat; Chadar, Dattatray; Saha, Sourav Kr.; Praharaj, Prakash Priyadarshi; Nagaraja, C. M.; Chakrovarty, Debamitra; Salunke-Gawali, Sunita

2016-12-01

Molecular structures and their molecular association of 2-(n-alkylamino)-1,4-naphthoquinone, viz., LH-3; propyl, LH-4; butyl and LH-8; octyl derivatives were studied by single crystal X-ray diffraction studies. Synthesis and characterization of 2-octylamino-1,4-naphthoquinone; LH-8 was discussed. The molecule of LH-3 crystallizes in orthorhombic space group P21/c, while the LH-4 and LH-8 molecule crystallizes in triclinic space group P-1. LH-3, LH-4 and LH-8 showed intermolecular N-H⋯O and C-H⋯O interactions, LH-3 showed unique C(3)-H(3)⋯O(1) interaction. Interchain π-π stacking, slipped π-π stacking and C⋯O close contacts was respectively observed in LH-3, LH-4 and LH-8. Electrochemical studies were performed on first eight members of homologous series of 2-(n-alkylamino)-1,4-naphthoquinone (LH-1 to LH-8) by cyclic voltammetry. Naphthoquinone to naphthosemiquinone reversible redox couple was observed in all compounds ∼ E1/2 = -0.657 ± 0.05 V. HOMO-LUMO band gap was determined for the neutral form as well as the monoanionic radical form viz. naphthosemiquinone form of selected derivatives by DFT studies. It has been observed that the electron density is delocalized in the naphthoquinone ring in both neutral as well as one electron reduced form of compounds. Antiproliferative activity of LH-1 to LH-8 was evaluated against two cancer cell lines, THP1(acute monocytic leukemia) and K562(human immortalized myelogenous leukemia cell line) cells. It was observed that, in THP1 cells, compounds LH-2 and LH-3 are very active while LH-1, LH-4 and LH-6 were moderately active and LH-5, LH-7 and LH-8 were totally inactive. Contrastingly, in K562 cells all of the compounds were moderately active.

Determination of soil–water sorption coefficients of volatile methylsiloxanes

PubMed Central

Kozerski, Gary E; Xu, Shihe; Miller, Julie; Durham, Jeremy

2014-01-01

The sorption behaviors of 4 cyclic and linear volatile methyl siloxane (VMS) compounds between water and organic matter in 3 United Kingdom soils were studied by a batch equilibrium method using13C-enriched sorbates. Sorption and desorption kinetics and isotherms were determined for octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), octamethyltrisiloxane (L3), and decamethyltetrasiloxane (L4). Concentrations of [13C]-VMS in the soil and aqueous phases were measured directly by extraction and gas chromatography–mass spectrometry techniques. All VMS compounds were sorbed rapidly, reaching constant distributions in all soils by 24 h. Desorption kinetics were very rapid, with reattainment of equilibrium within 1 h. In the main, linear isotherms were observed for aqueous concentrations at or below 4% of the solubility limits. The average sorption organic carbon partition coefficient (log KOC) values across soils were 4.23 for D4, 5.17 for D5, 4.32 for L3, and 5.13 for L4, with standard deviations of 0.09 to 0.34. Desorption KOC values were systematically greater by 0.1 log units to 0.3 log units. The linear isotherms and low variation in KOC values across soils suggested partitioning-dominated sorption of the VMS. Compared with traditional hydrophobic organic compounds, KOC values for the VMS compounds were significantly lower than expected on the basis of their octanol–water partition coefficients. A linear free energy relationship analysis showed that these differences could be rationalized quantitatively in terms of the inherent characteristics of the VMS compounds, combined with the differences in solvation properties of organic matter and octanol. Environ Toxicol Chem 2014; 33:1937–1945. PMID:24862578

Geranylated flavonoids from the roots of Campylotropis hirtella and their immunosuppressive activities.

PubMed

Shou, Qing-Yao; Fu, Run-Zhong; Tan, Qing; Shen, Zheng-Wu

2009-08-12

In an effort to identify new immunosuppressive agents from natural sources, 12 new geranylated flavonoids, 5,7,4'-trihydroxy-3'-[7-hydroxy-3,7-dimethyl-2(E)-octenyl]isoflavone (1), a racemate of 5,7,2',4'-tetrahydroxy-3'-[7-hydroxy-3,7-dimethyl-2(E)-octenyl]isoflavanone (2), 2''(S)-5,7-dihydroxy-[2''-methyl-2''-(4-methyl-3-pentenyl)pyrano]-5'',6'':3',4'-isoflavone (3), (2''S,3''R,4''S)-5,7,3'',4''-tetrahydroxy[2''-methyl-2''-(4-methyl-3-pentenyl)pyrano]-5'',6'':3',4'-isoflavone (4), a racemate of 3'-geranyl-5,7,2',4'-tetrahydroxyisoflavanone (5), a racemate of 3'-geranyl-4'-methoxy-5,7,2'-trihydroxyisoflavanone (6), 3'-geranyl-5,7,4',5'-tetrahydroxyisoflavone (8), 3'-geranyl-5,7,2',5'-tetrahydroxyisoflavone (9), 3'-geranyl-4'-methoxy-5,7,2'-trihydroxyisoflavone (10), 2(R),3(R)-3'-geranyl-2,3-trans-5,7,4'-trihydroxyflavonol (12), (2R,3R)-6-methyl-3'-geranyl-2,3-trans-5,7,4'-trihydroxyflavonol (13), and 5,7-dihydroxy-4'-O-geranylisoflavone (14), were isolated from the roots of Campylotropis hirtella (Franch.) Schindl. together with three previously described flavonoids. Their structures were elucidated by spectroscopic measurements, including two-dimensional nuclear magnetic resonance (NMR) techniques. The immunosuppressive effects of these compounds were assessed using mitogen-induced splenocyte proliferation, and the cytotoxicity of the compounds was also examined. The IC50 values of the compounds were found to be in the range of 1.49-61.23 microM for T lymphocyte suppression and 1.16-73.07 microM for B lymphocyte suppression. An analysis of their structure-activity relationships revealed that an isoflavonoid carbon skeleton with a C10 substituent at the C3' position was necessary for the activity. As many of the compounds exhibited good immunosuppressive activities, they may be promising as novel immunosuppressive agents.

Stability of the 1144 phase in iron pnictides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, B. Q.; Nguyen, Manh Cuong; Wang, C. Z.

A series of iron arsenides (e.g., CaRbFe 4As 4, SrCsFe 4As 4) have been discovered recently, and have provoked a rise in superconductor searches in a different phase, known as the 1144 phase. For the presence of various chemical substitutions, it is believed that more 1144 compounds remain to be discovered. Here in this work, we perform general model analysis as well as scenario calculation on a basis of density functional theory to investigate phase stability in a variety of compounds. We predict that the 1144-type phase could be stabilized in EuKFe 4As 4, EuRbFe 4As 4, EuCsFe 4As 4,more » CaCsFe 4P 4, SrCsFe 4P 4, BaCsFe 4P 4, InCaFe 4As 4, InSrFe 4As 4, etc. Remarkably, it involves rare earths, trivalence elements (e.g., indium) and iron phosphides, which greatly expands the range of its existence and suggests a promising prospect for experimental synthesis. In addition, we find that the formation of many random doping compounds (e.g., Ba 0.5Cs 0.5Fe 2As 2, Ba 0.5 Rb 0.5Fe 2As 2) is driven by entropy and could be annealed to a 1144-type phase. Eventually, we plot a phase diagram about two structural factors Δa and Δc, giving a bird's-eye view of stability of various 1144 compounds.« less

Stability of the 1144 phase in iron pnictides

DOE PAGES

Song, B. Q.; Nguyen, Manh Cuong; Wang, C. Z.; ...

2018-03-14

A series of iron arsenides (e.g., CaRbFe 4As 4, SrCsFe 4As 4) have been discovered recently, and have provoked a rise in superconductor searches in a different phase, known as the 1144 phase. For the presence of various chemical substitutions, it is believed that more 1144 compounds remain to be discovered. Here in this work, we perform general model analysis as well as scenario calculation on a basis of density functional theory to investigate phase stability in a variety of compounds. We predict that the 1144-type phase could be stabilized in EuKFe 4As 4, EuRbFe 4As 4, EuCsFe 4As 4,more » CaCsFe 4P 4, SrCsFe 4P 4, BaCsFe 4P 4, InCaFe 4As 4, InSrFe 4As 4, etc. Remarkably, it involves rare earths, trivalence elements (e.g., indium) and iron phosphides, which greatly expands the range of its existence and suggests a promising prospect for experimental synthesis. In addition, we find that the formation of many random doping compounds (e.g., Ba 0.5Cs 0.5Fe 2As 2, Ba 0.5 Rb 0.5Fe 2As 2) is driven by entropy and could be annealed to a 1144-type phase. Eventually, we plot a phase diagram about two structural factors Δa and Δc, giving a bird's-eye view of stability of various 1144 compounds.« less

Stability of the 1144 phase in iron pnictides

NASA Astrophysics Data System (ADS)

Song, B. Q.; Nguyen, Manh Cuong; Wang, C. Z.; Ho, K. M.

2018-03-01

A series of iron arsenides (e.g., CaRbFe4As4 , SrCsFe4As4 ) have been discovered recently, and have provoked a rise in superconductor searches in a different phase, known as the 1144 phase. For the presence of various chemical substitutions, it is believed that more 1144 compounds remain to be discovered. In this work, we perform general model analysis as well as scenario calculation on a basis of density functional theory to investigate phase stability in a variety of compounds. We predict that the 1144-type phase could be stabilized in EuKFe4As4 , EuRbFe4As4 , EuCsFe4As4 , CaCsFe4P4 , SrCsFe4P4 , BaCsFe4P4 , InCaFe4As4 , InSrFe4As4 , etc. Remarkably, it involves rare earths, trivalence elements (e.g., indium) and iron phosphides, which greatly expands the range of its existence and suggests a promising prospect for experimental synthesis. In addition, we find that the formation of many random doping compounds (e.g., Ba0.5Cs0.5Fe2As2 , Ba0.5Rb0.5Fe2As2 ) is driven by entropy and could be annealed to a 1144-type phase. Eventually, we plot a phase diagram about two structural factors Δ a and Δ c , giving a bird's-eye view of stability of various 1144 compounds.