Nucleoside-O-Methyl-(H)-Phosphinates: Novel Monomers for the Synthesis of Methylphosphonate Oligonucleotides Using H-Phosphonate Chemistry.

PubMed

Kostov, Ondřej; Páv, Ondřej; Rosenberg, Ivan

2017-09-18

This unit comprises the straightforward synthesis of protected 2'-deoxyribonucleoside-O-methyl-(H)-phosphinates in both 3'- and 5'-series. These compounds represent a new class of monomers compatible with the solid-phase synthesis of oligonucleotides using H-phosphonate chemistry and are suitable for the preparation of both 3'- and 5'-O-methylphosphonate oligonucleotides. The synthesis of 4-toluenesulfonyloxymethyl-(H)-phosphinic acid as a new reagent for the preparation of O-methyl-(H)-phosphinic acid derivatives is described. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

DNA methylation of amino acid transporter genes in the human placenta.

PubMed

Simner, C; Novakovic, B; Lillycrop, K A; Bell, C G; Harvey, N C; Cooper, C; Saffery, R; Lewis, R M; Cleal, J K

2017-12-01

Placental transfer of amino acids via amino acid transporters is essential for fetal growth. Little is known about the epigenetic regulation of amino acid transporters in placenta. This study investigates the DNA methylation status of amino acid transporters and their expression across gestation in human placenta. BeWo cells were treated with 5-aza-2'-deoxycytidine to inhibit methylation and assess the effects on amino acid transporter gene expression. The DNA methylation levels of amino acid transporter genes in human placenta were determined across gestation using DNA methylation array data. Placental amino acid transporter gene expression across gestation was also analysed using data from publically available Gene Expression Omnibus data sets. The expression levels of these transporters at term were established using RNA sequencing data. Inhibition of DNA methylation in BeWo cells demonstrated that expression of specific amino acid transporters can be inversely associated with DNA methylation. Amino acid transporters expressed in term placenta generally showed low levels of promoter DNA methylation. Transporters with little or no expression in term placenta tended to be more highly methylated at gene promoter regions. The transporter genes SLC1A2, SLC1A3, SLC1A4, SLC7A5, SLC7A11 and SLC7A10 had significant changes in enhancer DNA methylation across gestation, as well as gene expression changes across gestation. This study implicates DNA methylation in the regulation of amino acid transporter gene expression. However, in human placenta, DNA methylation of these genes remains low across gestation and does not always play an obvious role in regulating gene expression, despite clear evidence for differential expression as gestation proceeds. Copyright © 2017. Published by Elsevier Ltd.

Synthesis of methyl 3-O-alpha-D-mannopyranosyl-alpha-D-talopyranoside and methyl 3-O-alpha-D-talopyranosyl-alpha-D-talopyranoside.

PubMed

Dubey, R; Jain, R K; Abbas, S A; Matta, K L

1987-08-01

Methyl 2-O-benzyl-3-O-(2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranosyl)-alpha- D-mannopyranoside (4) and methyl 2-O-benzyl-3-O-alpha-D-mannopyranosyl-alpha-D-mannopyranoside (6) were prepared from a common intermediate, namely, methyl 2-O-benzyl-4,6-O-benzylidene-3-O-(2,3,4,6-tetra-O-acetyl-alpha-D- mannopyranosyl)-alpha-D-mannopyranoside. On treatment with tert-butylchlorodiphenylsilane, in N,N-dimethylformamide in the presence of imidazole, 4 and 6 afforded methyl 2-O-benzyl-6-O-tert-butyldiphenylsilyl-3-O-(2,3,4,6-tetra-O-acetyl -alpha-D- mannopyranosyl)-alpha-D-mannopyranoside (7), and methyl 2-O-benzyl-6-O-tert-butyldiphenylsilyl-3-O-(6-O-tert- butyldiphenylsilyl-alpha-D-mannopyranosyl)-alpha-D-mannopyranoside (8), respectively. Compound 8 was converted into its 2,3-O-isopropylidene derivative (9), and oxidation of 7 and 9 with pyridinium chlorochromate, and reduction of the resulting carbonyl intermediates gave methyl 2-O-benzyl-6-O-tert-butyldiphenylsilyl-3-O-(2,3,4,6-tetra-O-acetyl -alpha-D- mannopyranosyl)-alpha-D-talopyranoside and methyl 2-O-benzyl-6-O-tert-butyldiphenylsilyl-3-O-(6-O-tert-butyldiphe nylsilyl- 2,3-O-isopropylidene-alpha-D-talopyranosyl)-alpha-D-talopyranoside , respectively. Removal of the protecting groups furnished the title disaccharides.

Resolution of 1-n-butyl-3-methyl-3-phospholene 1-oxide with TADDOL derivatives and calcium salts of O,O'-Dibenzoyl-(2R,3R)- or O,O'-di-p-toluoyl-(2R,3R)-tartaric acid.

PubMed

Bagi, Péter; Fekete, András; Kállay, Mihály; Hessz, Dóra; Kubinyi, Miklós; Holczbauer, Tamás; Czugler, Mátyás; Fogassy, Elemér; Keglevich, György

2014-03-01

The resolution methods applying (-)-(4R,5R)-4,5-bis(diphenylhydroxymethyl)-2,2-dimethyldioxolane ("TADDOL"), (-)-(2R,3R)-α,α,α',α'-tetraphenyl-1,4-dioxaspiro[4.5]decan-2,3-dimethanol ("spiro-TADDOL"), as well as the acidic and neutral Ca(2+) salts of (-)-O,O'-dibenzoyl- and (-)-O,O'-di-p-toluoyl-(2R,3R)-tartaric acid were extended for the preparation of 1-n-butyl-3-methyl-3-phospholene 1-oxide in optically active form. In one case, the intermediate diastereomeric complex could be identified by single-crystal X-ray analysis. The absolute P-configuration of the enantiomers of the phospholene oxide was also determined by comparing the experimentally obtained and calculated CD spectra. © 2014 Wiley Periodicals, Inc.

Functional analysis of a tomato salicylic acid methyl transferase and its role in synthesis of the flavor volatile methyl salicylate

USDA-ARS?s Scientific Manuscript database

Methyl salicylate (MeSA) is a volatile plant secondary metabolite that is an important contributor to taste and scent of many fruits and flowers. It is synthesized from salicylic acid (SA), a phytohormone that contributes to plant pathogen defense. MeSA is synthesized by members of a family of O-met...

X-ray diffraction, vibrational and quantum chemical investigations of 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid.

PubMed

Arjunan, V; Marchewka, Mariusz K; Pietraszko, A; Kalaivani, M

2012-11-01

The structural investigations of the molecular complex of 2-methyl-4-nitroaniline with trichloroacetic acid, namely 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid (C(11)H(10)Cl(6)N(2)O(6)) have been performed by means of single crystal and powder X-ray diffraction method. The complex was formed with accompanying proton transfer from trichloroacetic acid molecule to 2-methyl-4-nitroaniline. The studied crystal is built up of singly protonated 2-methyl-4-nitroanilinium cations, trichloroacetate anions and neutral trichloroacetic acid molecules. The crystals are monoclinic, space group P2(1)/c, with a=14.947Å, b=6.432Å, c=19.609Å and Z=4. The vibrational assignments and analysis of 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid have also been performed by FTIR, FT-Raman and far-infrared spectral studies. More support on the experimental findings were added from the quantum chemical studies performed with DFT (B3LYP) method using 6-31G, cc-pVDZ, 6-31G and 6-31++G basis sets. The structural parameters, energies, thermodynamic parameters and the NBO charges of 2M4NATCA were also determined by the DFT methods. Copyright © 2012 Elsevier B.V. All rights reserved.

6-methyl-8-hexadecenoic acid: A novel fatty acid from the marine spongeDesmapsama anchorata.

PubMed

Carballeira, N M; Maldonado, M E

1988-07-01

The novel fatty acid 7-methyl-8-hexadecenoic (1) was identified in the marine spongeDesmapsama anchorata. Other interesting fatty acids identified were 14-methyl-8-hexadecenoic (2), better known through its methyl ester as one of the components of the sex attractant of the female dermestid beetle, and the saturated fatty acid 3-methylheptadecanoic (3), known to possess larvicidal activity. The main phospholipid fatty acids encountered inD. anchorata were palmitic (16∶0), behenic (22∶0) and 5,9-hexacosadienoic acid (26∶2), which together accounted for 50% of the total phospholipid fatty acid mixture.

Destruction of C2H4O2 isomers in ice-phase by X-rays: Implication on the abundance of acetic acid and methyl formate in the interstellar medium

NASA Astrophysics Data System (ADS)

Rachid, Marina G.; Faquine, Karla; Pilling, S.

2017-12-01

The C2H4O2 isomers methyl formate (HCOOCH3), acetic acid (CH3COOH) and glycoaldehyde (HOCH2CHO) have been detected in molecular clouds in the interstellar medium, as well as, hot cores, hot corinos and around protostellar objects. However, their abundances are very different, being methyl formate more abundant than the other two isomers. This fact may be related to the different destruction by ionizing radiation of these molecules. The goal of this work is experimentally study the photodissociation processes of methyl formate and acetic acid ices when exposed to broadband soft X-ray from 6 up to 2000 eV. The experiments were performed coupled to the SGM beamline in the Brazilian Synchrotron Light Source (LNLS/CNPEM) at Campinas, Brazil. The simulated astrophysical ices (12 K) were monitored throughout the experiment using infrared vibrational spectroscopy (FTIR). The analysis of processed ices allowed the determination of the effective destruction cross sections of the parent molecules as well as the effective formation cross section of daughter molecular species such as CO, CO2, H2O, CH4 and H2CO (only for methyl formate) and the hydrocarbons C2H6 and C5H10 (only for acetic acid). The half-lives of molecules at ices toward young stellar objects (YSOs) and inside molecular clouds (e.g. Sgr B2 and W51) due to the presence of incoming soft X-rays were estimated. We determined the effective formation rate and the branching ratios for assigned daughter species after the establishment of a chemical equilibrium. The main product from photodissociation of both methyl formate and acetic acid is CO, that can be formed by recombination of ions, formed during the photodissociation, in the ice surface. The relative abundance between methyl formate and acetic acid (NCH3COOH/NHCOOCH3) in different astronomical scenarios and their column density evolution in the presence of X-rays were calculated. Our results suggest that such radiation field can be one of the factors that

Synthesis of methyl 2-O-alpha-D-mannopyranosyl-alpha-D-talopyranoside and methyl 2-O-alpha-D-talopyranosyl-alpha-D-talopyranoside.

PubMed

Jain, R K; Dubey, R; Abbas, S A; Matta, K L

1987-03-15

Treatment of methyl 3-O-benzyl-2-O-(2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranosyl)-alpha-D- mannopyranoside (1) with tert-butyldiphenylsilyl chloride in N,N-dimethylformamide afforded methyl 3-O-benzyl-6-O-tert-butyldiphenylsilyl-2-O-(2,3,4,6-tetra-O-acetyl -alpha-D- mannopyranosyl)-alpha-D-mannopyranoside (2). Oxidation of 2 with pyridinium chlorochromate, followed by reduction of the carbonyl group, and subsequent O-deacetylation afforded methyl 3-O-benzyl-6-O-tert-butyldiphenylsilyl-2-O-alpha-D-mannopyranosyl- alpha-D- talopyranoside (5). Cleavage of the tert-butyldiphenylsilyl group of 5 with tetrabutylammonium fluoride in oxolane, followed by hydrogenolysis, gave methyl 2-O-alpha-D-mannopyranosyl-alpha-D-talopyranoside (7). O-Deacetylation of 1 gave methyl 3-O-benzyl-2-O-alpha-D-mannopyranosyl-alpha-D-mannopyranoside (8). Treatment of 8 with tert-butyldiphenylsilyl chloride afforded a 6,6'-disilyl derivative, which was converted into a 2',3'-O-isopropylidene derivative, and then further oxidized with pyridinium chlorochromate. The resulting diketone was reduced and removal of the protecting groups gave methyl 2-O-alpha-D-talopyranosyl-alpha-D-talopyranoside (15). The structures of both 7 and 15 were established by 13C-n.m.r. spectroscopy.

A novel multifunctional O-methyltransferase implicated in a dual methylation pathway associated with lignin biosynthesis in loblolly pine

PubMed Central

Li, Laigeng; Popko, Jacqueline L.; Zhang, Xing-Hai; Osakabe, Keishi; Tsai, Chung-Jui; Joshi, Chandrashekhar P.; Chiang, Vincent L.

1997-01-01

S-adenosyl-l-methionine (SAM)-dependent O-methyltransferases (OMTs) catalyze the methylation of hydroxycinnamic acid derivatives for the synthesis of methylated plant polyphenolics, including lignin. The distinction in the extent of methylation of lignins in angiosperms and gymnosperms, mediated by substrate-specific OMTs, represents one of the fundamental differences in lignin biosynthesis between these two classes of plants. In angiosperms, two types of structurally and functionally distinct lignin pathway OMTs, caffeic acid 3-O-methyltransferases (CAOMTs) and caffeoyl CoA 3-O-methyltransferases (CCoAOMTs), have been reported and extensively studied. However, little is known about lignin pathway OMTs in gymnosperms. We report here the first cloning of a loblolly pine (Pinus taeda) xylem cDNA encoding a multifunctional enzyme, SAM:hydroxycinnamic Acids/hydroxycinnamoyl CoA Esters OMT (AEOMT). The deduced protein sequence of AEOMT is partially similar to, but clearly distinguishable from, that of CAOMTs and does not exhibit any significant similarity with CCoAOMT protein sequences. However, functionally, yeast-expressed AEOMT enzyme catalyzed the methylation of CAOMT substrates, caffeic and 5-hydroxyferulic acids, as well as CCoAOMT substrates, caffeoyl CoA and 5-hydroxyferuloyl CoA esters, with similar specific activities and was completely inactive with substrates associated with flavonoid synthesis. The lignin-related substrates were also efficiently methylated in crude extracts of loblolly pine secondary xylem. Our results support the notion that, in the context of amino acid sequence and biochemical function, AEOMT represents a novel SAM-dependent OMT, with both CAOMT and CCoAOMT activities and thus the potential to mediate a dual methylation pathway in lignin biosynthesis in loblolly pine xylem. PMID:9144260

A novel multifunctional O-methyltransferase implicated in a dual methylation pathway associated with lignin biosynthesis in loblolly pine.

PubMed

Li, L; Popko, J L; Zhang, X H; Osakabe, K; Tsai, C J; Joshi, C P; Chiang, V L

1997-05-13

S-adenosyl-L-methionine (SAM)-dependent O-methyltransferases (OMTs) catalyze the methylation of hydroxycinnamic acid derivatives for the synthesis of methylated plant polyphenolics, including lignin. The distinction in the extent of methylation of lignins in angiosperms and gymnosperms, mediated by substrate-specific OMTs, represents one of the fundamental differences in lignin biosynthesis between these two classes of plants. In angiosperms, two types of structurally and functionally distinct lignin pathway OMTs, caffeic acid 3-O-methyltransferases (CAOMTs) and caffeoyl CoA 3-O-methyltransferases (CCoAOMTs), have been reported and extensively studied. However, little is known about lignin pathway OMTs in gymnosperms. We report here the first cloning of a loblolly pine (Pinus taeda) xylem cDNA encoding a multifunctional enzyme, SAM:hydroxycinnamic Acids/hydroxycinnamoyl CoA Esters OMT (AEOMT). The deduced protein sequence of AEOMT is partially similar to, but clearly distinguishable from, that of CAOMTs and does not exhibit any significant similarity with CCoAOMT protein sequences. However, functionally, yeast-expressed AEOMT enzyme catalyzed the methylation of CAOMT substrates, caffeic and 5-hydroxyferulic acids, as well as CCoAOMT substrates, caffeoyl CoA and 5-hydroxyferuloyl CoA esters, with similar specific activities and was completely inactive with substrates associated with flavonoid synthesis. The lignin-related substrates were also efficiently methylated in crude extracts of loblolly pine secondary xylem. Our results support the notion that, in the context of amino acid sequence and biochemical function, AEOMT represents a novel SAM-dependent OMT, with both CAOMT and CCoAOMT activities and thus the potential to mediate a dual methylation pathway in lignin biosynthesis in loblolly pine xylem.

Neural Tube Defects, Folic Acid and Methylation

PubMed Central

Imbard, Apolline; Benoist, Jean-François; Blom, Henk J.

2013-01-01

Neural tube defects (NTDs) are common complex congenital malformations resulting from failure of the neural tube closure during embryogenesis. It is established that folic acid supplementation decreases the prevalence of NTDs, which has led to national public health policies regarding folic acid. To date, animal studies have not provided sufficient information to establish the metabolic and/or genomic mechanism(s) underlying human folic acid responsiveness in NTDs. However, several lines of evidence suggest that not only folates but also choline, B12 and methylation metabolisms are involved in NTDs. Decreased B12 vitamin and increased total choline or homocysteine in maternal blood have been shown to be associated with increased NTDs risk. Several polymorphisms of genes involved in these pathways have also been implicated in risk of development of NTDs. This raises the question whether supplementation with B12 vitamin, betaine or other methylation donors in addition to folic acid periconceptional supplementation will further reduce NTD risk. The objective of this article is to review the role of methylation metabolism in the onset of neural tube defects. PMID:24048206

A 13C NMR study of the structure of four cinnamic acids and their methyl esters

NASA Astrophysics Data System (ADS)

Silva, A. M. S.; Alkorta, I.; Elguero, J.; Silva, V. L. M.

2001-09-01

The 13C NMR spectra, both in DMSO solution and in the solid state of four cinnamic acids (p-methoxy, p-hydroxy, p-methyl, p-chloro) and their corresponding methyl esters have been recorded. The two main results in the solid state are: (i) the only significant difference between acids and esters chemical shifts concerns the Cdbnd O group which, on average, appears at 173 ppm in the acids and 168 ppm in the esters; (ii) the signals of the ortho and meta carbons both in the acids and the esters are splitted. The two 'anomalies' disappear in DMSO solution. These observations can be rationalized using simple GIAO/B3LYP/6-31G∗ calculations.

Antiviral Activity of Nordihydroguaiaretic Acid and Its Derivative Tetra-O-Methyl Nordihydroguaiaretic Acid against West Nile Virus and Zika Virus.

PubMed

Merino-Ramos, Teresa; Jiménez de Oya, Nereida; Saiz, Juan-Carlos; Martín-Acebes, Miguel A

2017-08-01

Flaviviruses are positive-strand RNA viruses distributed all over the world that infect millions of people every year and for which no specific antiviral agents have been approved. These viruses include the mosquito-borne West Nile virus (WNV), which is responsible for outbreaks of meningitis and encephalitis. Considering that nordihydroguaiaretic acid (NDGA) has been previously shown to inhibit the multiplication of the related dengue virus and hepatitis C virus, we have evaluated the effect of NDGA, and its methylated derivative tetra- O -methyl nordihydroguaiaretic acid (M 4 N), on the infection of WNV. Both compounds inhibited the infection of WNV, likely by impairing viral replication. Since flavivirus multiplication is highly dependent on host cell lipid metabolism, the antiviral effect of NDGA has been previously related to its ability to disturb the lipid metabolism, probably by interfering with the sterol regulatory element-binding proteins (SREBP) pathway. Remarkably, we observed that other structurally unrelated inhibitors of the SREBP pathway, such as PF-429242 and fatostatin, also reduced WNV multiplication, supporting that the SREBP pathway may constitute a druggable target suitable for antiviral intervention against flavivirus infection. Moreover, treatment with NDGA, M 4 N, PF-429242, and fatostatin also inhibited the multiplication of the mosquito-borne flavivirus Zika virus (ZIKV), which has been recently associated with birth defects (microcephaly) and neurological disorders. Our results point to SREBP inhibitors, such as NDGA and M 4 N, as potential candidates for further antiviral development against medically relevant flaviviruses. Copyright © 2017 American Society for Microbiology.

Complexes of polyadenylic acid and the methyl esters of amino acids

NASA Technical Reports Server (NTRS)

Khaled, M. A.; Mulins, D. W., Jr.; Swindle, M.; Lacey, J. C., Jr.

1983-01-01

A study of amino acid methyl esters binding to polyadenylic acid supports the theory that the genetic code originated through weak but selective affinities between amino acids and nucleotides. NMR, insoluble complex analysis, and ultraviolet spectroscopy are used to illustrate a correlation between the hydrophybicities of A amino acids and their binding constants, which, beginning with the largest, are in the order of Phe (having nominally a hydrophobic AAA anticodon), Ile, Leu, Val and Gly (having a hydrophilic anticodon with no A). In general, the binding constants are twice the values by Reuben and Polk (1980) for monomeric AMP, which suggests that polymer amino acids are interacting with only one base. No real differences are found betwen poly A binding for free Phe, Phe methyl ester or Phe amide, except that the amide value is slightly lower.

40 CFR 721.10122 - 2-Propenoic acid, 2-methyl-, 1,1′-[2-ethyl-2-[[(2-methyl-1-oxo-2-propen-1-yl)oxy]methyl]- 1,3...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 2-Propenoic acid, 2-methyl-, 1,1â²-[2... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10122 2-Propenoic acid, 2-methyl-, 1,1... new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2-methyl-, 1...

40 CFR 721.10122 - 2-Propenoic acid, 2-methyl-, 1,1′-[2-ethyl-2-[[(2-methyl-1-oxo-2-propen-1-yl)oxy]methyl]- 1,3...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false 2-Propenoic acid, 2-methyl-, 1,1â²-[2... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10122 2-Propenoic acid, 2-methyl-, 1,1... new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2-methyl-, 1...

40 CFR 721.10122 - 2-Propenoic acid, 2-methyl-, 1,1′-[2-ethyl-2-[[(2-methyl-1-oxo-2-propen-1-yl)oxy]methyl]- 1,3...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 2-Propenoic acid, 2-methyl-, 1,1â²-[2... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10122 2-Propenoic acid, 2-methyl-, 1,1... new uses subject to reporting. (1) The chemical substance identified as 2-propenoic acid, 2-methyl-, 1...

2'-O-methylation in mRNA disrupts tRNA decoding during translation elongation.

PubMed

Choi, Junhong; Indrisiunaite, Gabriele; DeMirci, Hasan; Ieong, Ka-Weng; Wang, Jinfan; Petrov, Alexey; Prabhakar, Arjun; Rechavi, Gideon; Dominissini, Dan; He, Chuan; Ehrenberg, Måns; Puglisi, Joseph D

2018-03-01

Chemical modifications of mRNA may regulate many aspects of mRNA processing and protein synthesis. Recently, 2'-O-methylation of nucleotides was identified as a frequent modification in translated regions of human mRNA, showing enrichment in codons for certain amino acids. Here, using single-molecule, bulk kinetics and structural methods, we show that 2'-O-methylation within coding regions of mRNA disrupts key steps in codon reading during cognate tRNA selection. Our results suggest that 2'-O-methylation sterically perturbs interactions of ribosomal-monitoring bases (G530, A1492 and A1493) with cognate codon-anticodon helices, thereby inhibiting downstream GTP hydrolysis by elongation factor Tu (EF-Tu) and A-site tRNA accommodation, leading to excessive rejection of cognate aminoacylated tRNAs in initial selection and proofreading. Our current and prior findings highlight how chemical modifications of mRNA tune the dynamics of protein synthesis at different steps of translation elongation.

Isopropyl methyl phosphonic acid (IMPA)

Integrated Risk Information System (IRIS)

Isopropyl methyl phosphonic acid ( IMPA ) ; CASRN 1832 - 54 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assess

Synthesis and properties of 2'-O-methyl-4'-thioRNA.

PubMed

Takahashi, Mayumi; Inoue, Naonori; Minakawa, Noriaki; Matsuda, Akira

2005-01-01

In this presentation, we will discuss the synthesis and properties of 2'-O-methyl-4'-thioRNA, an RNA molecule consisting of 2'-O-methyl-4'-thionucleosides. We first synthesized 2'-O-methyl-4'-thiouridine and -cytidine derivatives via 2,2'-O-anhydro-4'-thiouridine. The RNA consisting of 2'-O-methyl-4'-thiopyrimidine nucleosides and 2'-O-methylpurine nucleosides, 2'-OMe-4'-thioRNA, was synthesized on a DNA synthesizer according to the standard phosphoramidite protocol.

Stimulatory Effects of Acibenzolar-S-Methyl on Chlorogenic Acids Biosynthesis in Centella asiatica Cells

PubMed Central

Ncube, Efficient N.; Steenkamp, Paul A.; Madala, Ntakadzeni E.; Dubery, Ian A.

2016-01-01

Centella asiatica is a perrenial herb that grows in tropical regions with numerous medicinal properties mostly attributed to the presence of pentacyclic triterpenoids. Interestingly, this plant also possess a significant amount of phenylpropanoid-derived chlorogenic acids (CGAs) that have recently been reported to confer neuroprotective properties. In a biotechnological attempt to increase the biosynthesis of CGA-derivatives in cultured Centella cells, acibenzolar-S-methyl was applied as a xenobiotic inducer in combination with quinic acid and shikimic acid as precursor molecules. Applying a semi-targeted metabolomics-based approach, time and concentration studies were undertaken to evaluate the effect of the manipulation on cellular metabolism leading to CGA production. Phytochemical extracts were prepared using methanol and analyzed using a UHPLC-qTOF-MS platform. Data was processed and analyzed using multivariate data models. A total of four CGA-derivatives, annotated as trans-5-feruloylquinic acid, 3,5 di-caffeoylquinic acid, 3,5-O-dicaffeoyl-4-O-malonylquinic acid (irbic acid) and 3-caffeoyl, 5-feruloylquinic acid, were found to be upregulated by the acibenzolar-S-methyl treatment. To the best of our knowledge, this is the first report on the induction of CGA derivatives in this species. Contrary to expectations, the effects of precursor molecules on the levels of the CGAs were insignificant. However, a total of 16 metabolites, including CGA derivatives, were up-regulated by precursor treatment. Therefore, this study shows potential to biotechnologically manipulate C. asiatica cells to increase the production of these health beneficial CGAs. PMID:27733862

Reactions of guanine with methyl chloride and methyl bromide: O6-methylation versus charge transfer complex formation

NASA Astrophysics Data System (ADS)

Shukla, P. K.; Mishra, P. C.; Suhai, S.

Density functional theory (DFT) at the B3LYP/6-31+G* and B3LYP/AUG-cc-pVDZ levels was employed to study O6-methylation of guanine due to its reactions with methyl chloride and methyl bromide and to obtain explanation as to why the methyl halides cause genotoxicity and possess mutagenic and carcinogenic properties. Geometries of the various isolated species involved in the reactions, reactant complexes (RCs), and product complexes (PCs) were optimized in gas phase. Transition states connecting the reactant complexes with the product complexes were also optimized in gas phase at the same levels of theory. The reactant complexes, product complexes, and transition states were solvated in aqueous media using the polarizable continuum model (PCM) of the self-consistent reaction field theory. Zero-point energy (ZPE) correction to total energy and the corresponding thermal energy correction to enthalpy were made in each case. The reactant complexes of the keto form of guanine with methyl chloride and methyl bromide in water are appreciably more stable than the corresponding complexes involving the enol form of guanine. The nature of binding in the product complexes was found to be of the charge transfer type (O6mG+ · X-, X dbond Cl, Br). Binding of HCl, HBr, and H2O molecules to the PCs obtained with the keto form of guanine did not alter the positions of the halide anions in the PCs, and the charge transfer character of the PCs was also not modified due to this binding. Further, the complexes obtained due to the binding of HCl, HBr, and H2O molecules to the PCs had greater stability than the isolated PCs. The reaction barriers involved in the formation of PCs were found to be quite high (?50 kcal/mol). Mechanisms of genotoxicity, mutagenesis and carcinogenesis caused by the methyl halides appear to involve charge transfer-type complex formation. Thus the mechanisms of these processes involving the methyl halides appear to be quite different from those that involve the

Measurement of formic acid, acetic acid and hydroxyacetaldehyde, hydrogen peroxide, and methyl peroxide in air by chemical ionization mass spectrometry: airborne method development

NASA Astrophysics Data System (ADS)

Treadaway, Victoria; Heikes, Brian G.; McNeill, Ashley S.; Silwal, Indira K. C.; O'Sullivan, Daniel W.

2018-04-01

A chemical ionization mass spectrometry (CIMS) method utilizing a reagent gas mixture of O2, CO2, and CH3I in N2 is described and optimized for quantitative gas-phase measurements of hydrogen peroxide (H2O2), methyl peroxide (CH3OOH), formic acid (HCOOH), and the sum of acetic acid (CH3COOH) and hydroxyacetaldehyde (HOCH2CHO; also known as glycolaldehyde). The instrumentation and methodology were designed for airborne in situ field measurements. The CIMS quantification of formic acid, acetic acid, and hydroxyacetaldehyde used I- cluster formation to produce and detect the ion clusters I-(HCOOH), I-(CH3COOH), and I-(HOCH2CHO), respectively. The CIMS also produced and detected I- clusters with hydrogen peroxide and methyl peroxide, I-(H2O2) and I-(CH3OOH), though the sensitivity was lower than with the O2- (CO2) and O2- ion clusters, respectively. For that reason, while the I- peroxide clusters are presented, the focus is on the organic acids. Acetic acid and hydroxyacetaldehyde were found to yield equivalent CIMS responses. They are exact isobaric compounds and indistinguishable in the CIMS used. Consequently, their combined signal is referred to as the acetic acid equivalent sum. Within the resolution of the quadrupole used in the CIMS (1 m/z), ethanol and 1- and 2-propanol were potential isobaric interferences to the measurement of formic acid and the acetic acid equivalent sum, respectively. The CIMS response to ethanol was 3.3 % that of formic acid and the response to either 1- or 2-propanol was 1 % of the acetic acid response; therefore, the alcohols were not considered to be significant interferences to formic acid or the acetic acid equivalent sum. The multi-reagent ion system was successfully deployed during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) in 2014. The combination of FRAPPÉ and laboratory calibrations allowed for the post-mission quantification of formic acid and the acetic acid equivalent sum observed during

Synthesis of methyl 2-O- and 3-O-alpha-D-talopyranosyl-alpha-D-mannopyranoside.

PubMed

Rana, S S; Matta, K L

1986-09-01

Methyl 3,4,6-tri-O-benzyl-2-O-[6-O-(tert-butyldiphenylsilyl)-alpha-D- mannopyranosyl]-alpha-D-mannopyranoside (2) was synthesized by treatment of methyl 3,4,6-tri-O-benzyl-2-O-alpha-D-mannopyranosyl-alpha-D-mannopyranoside with tert-butylchlorodiphenylsilane in the presence of imidazole. Isopropylidenation, followed by oxidation with pyridinium chlorochromate, and stereoselective reduction with sodium borohydride, converted 2 into methyl 3,4,6-tri-O-benzyl-2-O-[6-O-(tert-butyldiphenylsilyl)-2,3-O-isopro pylidene- alpha-D-talopyranosyl]-alpha-D-mannopyranoside (5). Treatment of 5 with a molar solution of tetrabutylammonium fluoride in dry oxolane produced a diol which, on O-de-isopropylidenation followed by catalytic hydrogenolysis, afforded the disaccharide glycoside methyl 2-O-alpha-D-talopyranosyl-alpha-D-mannopyranoside. Synthesis of methyl 3-O-alpha-D-talopyranosyl-alpha-D-mannopyranoside was accomplished by a similar reaction-sequence. The structures of the final disaccharides, and of various other intermediates, were established by 1H- and 13C-n.m.r. spectroscopy.

O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside.

PubMed

Sommer, Roman; Hauck, Dirk; Varrot, Annabelle; Imberty, Anne; Künzler, Markus; Titz, Alexander

2016-01-01

Selenoglycosides are used as reactive glycosyl donors in the syntheses of oligosaccharides. In addition, such heavy atom analogs of natural glycosides are useful tools for structure determination of their lectin receptors using X-ray crystallography. Some lectins, e.g., members of the tectonin family, only bind to carbohydrate epitopes with O-alkylated ring hydroxy groups. In this context, we report the first synthesis of an O -methylated selenoglycoside, specifically methyl 2- O -methyl-L-selenofucopyranoside, a ligand of the lectin tectonin-2 from the mushroom Laccaria bicolor . The synthetic route required a strategic revision and further optimization due to the intrinsic lability of alkyl selenoglycosides, in particular for the labile fucose. Here, we describe a successful synthetic access to methyl 2- O -methyl-L-selenofucopyranoside in 9 linear steps and 26% overall yield starting from allyl L-fucopyranoside.

Convenient synthesis of 6-nor-9,10-dihydrolysergic acid methyl ester.

PubMed

Crider, A M; Grubb, R; Bachmann, K A; Rawat, A K

1981-12-01

6-Nor-9,10-dihydrolysergic acid methyl ester (IV) was prepared by demethylation of 9,10-dihydrolysergic acid methyl ester (II) with 2,2,2-trichloroethyl chloroformate, followed by reduction of the intermediate carbamate (III) with zinc in acetic acid. The 6-ethyl-V and 6-n-propyl-VI derivatives were prepared by alkylation of IV with the appropriate halide. All of the ergoline derivatives were evaluated for stereotyped behavior in rats, with 6-nor-6-ethyl-9,10-dihydrolysergic acid methyl ester (V) being active but much less potent than apomorphine. Compound VI was evaluated for its effect on blood pressure; at a dose of 30 mg/kg ip, it significantly lowered, diastolic pressure in normotensive rats.

Effect of methyl jasmonate application to grapevine leaves on grape amino acid content.

PubMed

Garde-Cerdán, Teresa; Portu, Javier; López, Rosa; Santamaría, Pilar

2016-07-15

Over the last few years, considerable attention has been paid to the application of elicitors to vineyard. However, research about the effect of elicitors on grape amino acid content is scarce. Therefore, the aim of this study was to evaluate the influence of foliar application of methyl jasmonate on must amino acid content. Results revealed that total amino acid content was not modified by the application of methyl jasmonate. However, the individual content of certain amino acids was increased as consequence of methyl jasmonate foliar application, i.e., histidine, serine, tryptophan, phenylalanine, tyrosine, asparagine, methionine, and lysine. Among them, phenylalanine content was considerably increased; this amino acid is precursor of phenolic and aromatic compounds. In conclusion, foliar application of methyl jasmonate improved must nitrogen composition. This finding suggests that methyl jasmonate treatment might be conducive to obtain wines of higher quality since must amino acid composition could affect the wine volatile composition and the fermentation kinetics. Copyright © 2016 Elsevier Ltd. All rights reserved.

EPR study of gamma-irradiated N-methyl-L-alanine, DL-2-methyl glutamic acid hemihydrate and Di-leucine hydrochloride in solid state

NASA Astrophysics Data System (ADS)

Sütçü, Kerem; Osmanoğlu, Y. Emre

2017-12-01

In this study, it was aimed to investigate ɣ-irradiated powders of N-methyl-L-alanine (NMLA), DL-2-methyl glutamic acid hemihydrate (DL2MGAH), and Di-leucine hydrochloride (DLHCl) at room temperature by electron paramagnetic resonance spectroscopy. After the γ-irradiation the samples indicated the existence of the CH3ĊNHCH3COOH, HOOCCH3NH2CĊHCH2COOH·1/2H2O and (CH3)2ĊCH2CH NHCOOHCOCH (NH2HCl) CH2CH (CH3)2 radicals, respectively. The spectral parameters of the radicals were determined. The results were compared with the earlier studies and discussed accordingly.

Cytosine methylation effects on the repair of O6-methylguanines within CG dinucleotides.

PubMed

Guza, Rebecca; Ma, Linan; Fang, Qingming; Pegg, Anthony E; Tretyakova, Natalia

2009-08-21

O(6)-alkyldeoxyguanine adducts induced by tobacco-specific nitrosamines are repaired by O(6)-alkylguanine DNA alkyltransferase (AGT), which transfers the O(6)-alkyl group from the damaged base to a cysteine residue within the protein. In the present study, a mass spectrometry-based approach was used to analyze the effects of cytosine methylation on the kinetics of AGT repair of O(6)-methyldeoxyguanosine (O(6)-Me-dG) adducts placed within frequently mutated 5'-CG-3' dinucleotides of the p53 tumor suppressor gene. O(6)-Me-dG-containing DNA duplexes were incubated with human recombinant AGT protein, followed by rapid quenching, acid hydrolysis, and isotope dilution high pressure liquid chromatography-electrospray ionization tandem mass spectrometry analysis of unrepaired O(6)-methylguanine. Second-order rate constants were calculated in the absence or presence of the C-5 methyl group at neighboring cytosine residues. We found that the kinetics of AGT-mediated repair of O(6)-Me-dG were affected by neighboring 5-methylcytosine ((Me)C) in a sequence-dependent manner. AGT repair of O(6)-Me-dG adducts placed within 5'-CG-3' dinucleotides of p53 codons 245 and 248 was hindered when (Me)C was present in both DNA strands. In contrast, cytosine methylation within p53 codon 158 slightly increased the rate of O(6)-Me-dG repair by AGT. The effects of (Me)C located immediately 5' and in the base paired position to O(6)-Me-dG were not additive as revealed by experiments with hypomethylated sequences. Furthermore, differences in dealkylation rates did not correlate with AGT protein affinity for cytosine-methylated and unmethylated DNA duplexes or with the rates of AGT-mediated nucleotide flipping, suggesting that (Me)C influences other kinetic steps involved in repair, e.g. the rate of alkyl transfer from DNA to AGT.

40 CFR 721.1645 - Benzenesulfonic acid, 4-methyl-, reaction products with oxirane mono[(C10-16-alkyloxy)methyl...

Code of Federal Regulations, 2011 CFR

2011-07-01

...-, reaction products with oxirane mono[(C10-16-alkyloxy)methyl] derivatives and 2,2,4(or 2,4,4)-trimethyl-1,6... Specific Chemical Substances § 721.1645 Benzenesulfonic acid, 4-methyl-, reaction products with oxirane...-methyl-, reaction products with oxirane mono[(C10-16-alkyloxy)methyl] derivatives and 2,2,4(or 2,4,4...

40 CFR 721.1645 - Benzenesulfonic acid, 4-methyl-, reaction products with oxirane mono[(C10-16-alkyloxy)methyl...

Code of Federal Regulations, 2010 CFR

2010-07-01

...-, reaction products with oxirane mono[(C10-16-alkyloxy)methyl] derivatives and 2,2,4(or 2,4,4)-trimethyl-1,6... Specific Chemical Substances § 721.1645 Benzenesulfonic acid, 4-methyl-, reaction products with oxirane...-methyl-, reaction products with oxirane mono[(C10-16-alkyloxy)methyl] derivatives and 2,2,4(or 2,4,4...

Genetic Basis for Rhizobium etli CE3 O-Antigen O-Methylated Residues That Vary According to Growth Conditions▿

PubMed Central

Ojeda, Kristylea J.; Box, Jodie M.; Noel, K. Dale

2010-01-01

The Rhizobium etli CE3 O antigen is a fixed-length heteropolymer with O methylation being the predominant type of sugar modification. There are two O-methylated residues that occur, on average, once per complete O antigen: a multiply O-methylated terminal fucose and 2-O methylation of a fucose residue within a repeating unit. The amount of the methylated terminal fucose decreases and the amount of 2-O-methylfucose increases when bacteria are grown in the presence of the host plant, Phaseolus vulgaris, or its seed exudates. Insertion mutagenesis was used to identify open reading frames required for the presence of these O-methylated residues. The presence of the methylated terminal fucose required genes wreA, wreB, wreC, wreD, and wreF, whereas 2-O methylation of internal fucoses required the methyltransferase domain of bifunctional gene wreM. Mutants lacking only the methylated terminal fucose, lacking only 2-O methylation, or lacking both the methylated terminal fucose and 2-O methylation exhibited no other lipopolysaccharide structural defects. Thus, neither of these decorations is required for normal O-antigen length, transport, or assembly into the final lipopolysaccharide. This is in contrast to certain enteric bacteria in which the absence of a terminal decoration severely affects O-antigen length and transport. R. etli mutants lacking only the methylated terminal fucose were not altered in symbiosis with host Phaseolus vulgaris, whereas mutants lacking only 2-O-methylfucose exhibited a delay in nodule development during symbiosis. These results support previous conclusions that the methylated terminal fucose is dispensable for symbiosis, whereas 2-O methylation of internal fucoses somehow facilitates early events in symbiosis. PMID:19948805

2-Methyl-4-chlorophenoxyacetic acid (MCPA)

Integrated Risk Information System (IRIS)

2 - Methyl - 4 - chlorophenoxyacetic acid ( MCPA ) ; CASRN 94 - 74 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard

Lipase catalyzed epoxidation of fatty acid methyl esters derived from unsaturated vegetable oils in absence of carboxylic acid.

PubMed

Sustaita-Rodríguez, Alejandro; Ramos-Sánchez, Víctor H; Camacho-Dávila, Alejandro A; Zaragoza-Galán, Gerardo; Espinoza-Hicks, José C; Chávez-Flores, David

2018-04-11

Nowadays the industrial chemistry reactions rely on green technologies. Enzymes as lipases are increasing its use in diverse chemical processes. Epoxidized fatty acid methyl esters obtained from transesterification of vegetable oils have recently found applications as polymer plasticizer, agrochemical, cosmetics, pharmaceuticals and food additives. In this research article, grapeseed, avocado and olive oils naturally containing high percents of mono and poly unsaturations were used as starting materials for the production of unsaturated fatty acid methyl esters. The effect of lauric acid as an active oxygen carrier was studied on epoxidation reactions where unsaturated fatty acid methyl esters were converted to epoxy fatty acid methyl esters using immobilized Candida antarctica Lipase type B as catalyst and hydrogen peroxide as oxygen donor at mild temperature and pressure conditions. After this study it was confirmed by 1 H NMR, 13 C NMR and GC-MS that the addition of lauric acid to the enzymatic reaction is unnecessary to transform the alkenes in to epoxides. It was found that quantitative conversions were possible in despite of a carboxylic acid absence.

Direct methylation procedure for converting fatty amides to fatty acid methyl esters in feed and digesta samples.

PubMed

Jenkins, T C; Thies, E J; Mosley, E E

2001-05-01

Two direct methylation procedures often used for the analysis of total fatty acids in biological samples were evaluated for their application to samples containing fatty amides. Methylation of 5 mg of oleamide (cis-9-octadecenamide) in a one-step (methanolic HCl for 2 h at 70 degrees C) or a two-step (sodium methoxide for 10 min at 50 degrees C followed by methanolic HCl for 10 min at 80 degrees C) procedure gave 59 and 16% conversions of oleamide to oleic acid, respectively. Oleic acid recovery from oleamide was increased to 100% when the incubation in methanolic HCl was lengthened to 16 h and increased to 103% when the incubation in methoxide was modified to 24 h at 100 degrees C. However, conversion of oleamide to oleic acid in an animal feed sample was incomplete for the modified (24 h) two-step procedure but complete for the modified (16 h) one-step procedure. Unsaturated fatty amides in feed and digesta samples can be converted to fatty acid methyl esters by incubation in methanolic HCl if the time of exposure to the acid catalyst is extended from 2 to 16 h.

(Di­methyl­phosphor­yl)methanaminium hydrogen oxalate–oxalic acid (2/1)

PubMed Central

Bialek, Sebastian; Clemens, Rebecca; Reiss, Guido J.

2014-01-01

The reaction of (di­methyl­phosphor­yl)methanamine (dpma) with oxalic acid in ethanol yielded the title solvated salt, C3H11NOP+·C2HO4 −·0.5C2H2O4. Its asymmetric unit consists of one dpmaH+ cation, one hydrogen oxalate anion and a half-mol­ecule of oxalic acid located around a twofold rotation axis. The H atom of the hydrogen oxalate anion is statistically disordered over two positions that are trans to each other. The hydrogen oxalate monoanion is not planar (bend angle ∼16°) whereas the oxalic acid molecule shows a significantly smaller bend angle (∼7°). In the crystal, the components are connected by strong O—H⋯O and much weaker N—H⋯O hydrogen bonds, leading to the formation of layers extending parallel to (001). The structure was refined from a racemically twinned crystal with twin components in an approximate 1:1 ratio. PMID:24765013

Metabolism of the 18O-methoxy substituent of 3-methoxybenzoic acid and other unlabeled methoxybenzoic acids by anaerobic bacteria.

PubMed Central

DeWeerd, K A; Saxena, A; Nagle, D P; Suflita, J M

1988-01-01

O-methyl substituents of aromatic compounds can provide C1 growth substrates for facultative and strict anaerobic bacteria isolated from diverse environments. The mechanism of the bioconversion of methoxylated benzoic acids to the hydroxylated derivatives was investigated with a model substrate and cultures of one anaerobic consortium, eight strict anaerobic bacteria, and one facultative anaerobic microorganism. Using high-pressure liquid chromatography and gas chromatography-mass spectral analysis, we found that a haloaromatic dehalogenating consortium, a dehalogenating isolate from that consortium, Eubacterium limosum, and a strain of Acetobacterium woodii metabolized 3-[methoxy-18O]methoxybenzoic acid (3-anisic acid) to 3-[hydroxy-18O]hydroxybenzoic acid stoichiometrically at rates of 1.5, 3.2, 52.4, and 36.7 nmol/min per mg of protein, respectively. A different strain of Acetobacterium and strains of Syntrophococcus, Clostridium, Desulfotomaculum, Enterobacter, and an anaerobic bacterium, strain TH-001, were unable to transform this compound. The O-demethylating ability of E. limosum was induced only with appropriate methoxylated benzoates but not with D-glucose, lactate, isoleucine, or methanol. Cross-acclimation and growth experiments with E. limosum showed a rate of metabolism that was an order of magnitude slower and showed no growth with either 4-methoxysalicylic acid (2-hydroxy-4-methoxybenzoic acid) or 4-anisic acid (4-methoxybenzoic acid) when adapted to 3-anisic acid. However, A. woodii NZva-16 showed slower rates and no growth with 3- or 4-methoxysalicylic acid when adapted to 3-anisic acid in similar experiments. The results clearly indicate a methyl rather than methoxy group removal mechanism for such reactions. PMID:3389815

DNA methyltransferase homologue TRDMT1 in Plasmodium falciparum specifically methylates endogenous aspartic acid tRNA.

PubMed

Govindaraju, Gayathri; Jabeena, C A; Sethumadhavan, Devadathan Valiyamangalath; Rajaram, Nivethika; Rajavelu, Arumugam

2017-10-01

In eukaryotes, cytosine methylation regulates diverse biological processes such as gene expression, development and maintenance of genomic integrity. However, cytosine methylation and its functions in pathogenic apicomplexan protozoans remain enigmatic. To address this, here we investigated the presence of cytosine methylation in the nucleic acids of the protozoan Plasmodium falciparum. Interestingly, P. falciparum has TRDMT1, a conserved homologue of DNA methyltransferase DNMT2. However, we found that TRDMT1 did not methylate DNA, in vitro. We demonstrate that TRDMT1 methylates cytosine in the endogenous aspartic acid tRNA of P. falciparum. Through RNA bisulfite sequencing, we mapped the position of 5-methyl cytosine in aspartic acid tRNA and found methylation only at C38 position. P. falciparum proteome has significantly higher aspartic acid content and a higher proportion of proteins with poly aspartic acid repeats than other apicomplexan pathogenic protozoans. Proteins with such repeats are functionally important, with significant roles in host-pathogen interactions. Therefore, TRDMT1 mediated C38 methylation of aspartic acid tRNA might play a critical role by translational regulation of important proteins and modulate the pathogenicity of the malarial parasite. Copyright © 2017 Elsevier B.V. All rights reserved.

Application of liquid chromatography/electrospray ionization ion trap tandem mass spectrometry for the evaluation of global nucleic acids: methylation in garden cress under exposure to CuO nanoparticles.

PubMed

Alcazar Magana, Armando; Wrobel, Kazimierz; Corrales Escobosa, Alma Rosa; Wrobel, Katarzyna

2016-01-15

A full understanding of the biological impact of nanomaterials demands analytical procedures suitable for the detection/quantification of epigenetic changes that occur in the exposed organisms. Here, the effect of CuO nanoparticles (NPs) on global methylation of nucleic acids in Lepidium sativum was evaluated by liquid chromatography/ion trap mass spectrometry. Enhanced selectivity toward cytosine-containing nucleosides was achieved by using their proton-bound dimers formed in positive electrospray ionization (ESI(+)) as precursor ions for multiple reaction monitoring (MRM) quantification based on one or two ion transitions. Plants were exposed to CuO NPs (0-1000 mg L(-1)); nucleic acid extracts were washed with bathocuproine disulfate; nucleosides were separated on a Luna C18 column coupled via ESI(+) to an AmaZon SL mass spectrometer (Bruker Daltonics). Cytidine, 2´-deoxycytidine, 5-methylcytidine, 5-methyl-2´-deoxycytidine and 5-hydroxymethyl-2´-deoxycytidine were quantified by MRM based on MS(3) ([2M+H](+)/[M+H](+)/[M+H-132](+) or [M+H-116](+)) and MS(2) ([2M+H](+)/[M+H](+) ). Bathocuproine disulfate, added as Cu(I) complexing agent, allowed for elimination of [2M+Cu](+) adducts from the mass spectra. Poorer instrumental detection limits were obtained for MS(3) (20-120 fmol) as compared to MS(2) (9.0-41 fmol); however, two ion transitions helped to eliminate matrix effects in plant extracts. The procedure was tested by analyzing salmon sperm DNA (Sigma) and applied for the evaluation of DNA and RNA methylation in plants; in the absence of NPs, 13.03% and 0.92% methylated cytosines were found in DNA and RNA, respectively; for NPs concentration >50 mg L(-1), DNA hypomethylation was observed with respect to unexposed plants. RNA methylation did not present significant changes upon plant exposure; 5-hydroxymethyl-2´-deoxycytidine was not detected in any sample. The MRM quantification proposed here of cytosine-containing nucleosides using their proton-bound homo

-HPLC determination of acidic d-amino acids and their N-methyl derivatives in biological tissues

PubMed Central

Tsesarskaia, Mara; Galindo, Erika; Szókán, Gyula; Fisher, George

2015-01-01

d-aspartate (d-Asp) and N-methyl-d-aspartate (NMDA) occur in the neuroendocrine systems of vertebrates and invertebrates where they play a role in hormone release and synthesis, neurotransmission, and memory and learning. N-methyl-d-glutamate (NMDG) has also been detected in marine bivalves. Several methods have been used to detect these amino acids, but they require pretreatment of tissue samples with o-phthaldialdehyde (OPA) to remove primary amino acids which interfere with the detection of NMDA and NMDG. We report here a one step derivatization procedure with the chiral reagent N-α-(5-fluoro-2,4-dinitrophenyl)-(d or l)-valine amide, FDNP-Val-NH2, a close analog of Marfey’s reagent but with better resolution and higher molar absorptivity. The diastereomers formed are separated by HPLC on an ODS-Hypersil column eluted with TFA/water – TFA/MeCN. UV absorption at 340 nm permits detection levels as low as 5–10 picomoles. D-Asp, NMDA and NMDG peaks are not obscured by other primary or secondary amino acids; hence pretreatment of tissues with OPA is not required. This method is highly reliable and fast (less than 40 minutes HPLC run). Using this method, we have detected D-Asp, NMDA and NMDG in several biological tissues (octopus brain, optical lobe, and bucchal mass; foot and mantle of the mollusk Scapharca broughtonii), confirming the results of other researchers. PMID:19277955

Proton affinity of methyl nitrate - Less than proton affinity of nitric acid

NASA Technical Reports Server (NTRS)

Lee, Timothy J.; Rice, Julia E.

1992-01-01

Several state-of-the-art ab initio quantum mechanical methods were used to investigate the equilibrium structure, dipole moments, harmonic vibrational frequencies, and IR intensities of methyl nitrate, methanol, and several structures of protonated methyl nitrate, using the same theoretical methods as in an earlier study (Lee and Rice, 1992) of nitric acid. The ab initio results for methyl nitrate and methanol were found to be in good agreement with available experimental data. The proton affinity (PA) of methyl nitrate was calculated to be 176.9 +/-5 kcal/mol, in excellent agreement with the experimental value 176 kcal/mol obtained by Attina et al. (1987) and less than the PA value of nitric acid. An explanation of the discrepancy of the present results with those of an earlier study on protonated nitric acid is proposed.

Cytosine Methylation Effects on the Repair of O6-Methylguanines within CG Dinucleotides*

PubMed Central

Guza, Rebecca; Ma, Linan; Fang, Qingming; Pegg, Anthony E.; Tretyakova, Natalia

2009-01-01

O6-Alkyldeoxyguanine adducts induced by tobacco-specific nitrosamines are repaired by O6-alkylguanine DNA alkyltransferase (AGT), which transfers the O6-alkyl group from the damaged base to a cysteine residue within the protein. In the present study, a mass spectrometry-based approach was used to analyze the effects of cytosine methylation on the kinetics of AGT repair of O6-methyldeoxyguanosine (O6-Me-dG) adducts placed within frequently mutated 5′-CG-3′ dinucleotides of the p53 tumor suppressor gene. O6-Me-dG-containing DNA duplexes were incubated with human recombinant AGT protein, followed by rapid quenching, acid hydrolysis, and isotope dilution high pressure liquid chromatography-electrospray ionization tandem mass spectrometry analysis of unrepaired O6-methylguanine. Second-order rate constants were calculated in the absence or presence of the C-5 methyl group at neighboring cytosine residues. We found that the kinetics of AGT-mediated repair of O6-Me-dG were affected by neighboring 5-methylcytosine (MeC) in a sequence-dependent manner. AGT repair of O6-Me-dG adducts placed within 5′-CG-3′ dinucleotides of p53 codons 245 and 248 was hindered when MeC was present in both DNA strands. In contrast, cytosine methylation within p53 codon 158 slightly increased the rate of O6-Me-dG repair by AGT. The effects of MeC located immediately 5′ and in the base paired position to O6-Me-dG were not additive as revealed by experiments with hypomethylated sequences. Furthermore, differences in dealkylation rates did not correlate with AGT protein affinity for cytosine-methylated and unmethylated DNA duplexes or with the rates of AGT-mediated nucleotide flipping, suggesting that MeC influences other kinetic steps involved in repair, e.g. the rate of alkyl transfer from DNA to AGT. PMID:19531487

Evolution of novel O-methyltransferases from the Vanilla planifolia caffeic acid O-methyltransferase.

PubMed

Li, Huaijun Michael; Rotter, David; Hartman, Thomas G; Pak, Fulya E; Havkin-Frenkel, Daphna; Belanger, Faith C

2006-06-01

The biosynthesis of many plant secondary compounds involves the methylation of one or more hydroxyl groups, catalyzed by O-methyltransferases (OMTs). Here, we report the characterization of two OMTs, Van OMT-2 and Van OMT-3, from the orchid Vanilla planifolia Andrews. These enzymes catalyze the methylation of a single outer hydroxyl group in substrates possessing a 1,2,3-trihydroxybenzene moiety, such as methyl gallate and myricetin. This is a substrate requirement not previously reported for any OMTs. Based on sequence analysis these enzymes are most similar to caffeic acid O-methyltransferases (COMTs), but they have negligible activity with typical COMT substrates. Seven of 12 conserved substrate-binding residues in COMTs are altered in Van OMT-2 and Van OMT-3. Phylogenetic analysis of the sequences suggests that Van OMT-2 and Van OMT-3 evolved from the V. planifolia COMT. These V. planifolia OMTs are new instances of COMT-like enzymes with novel substrate preferences.

Studies of the acidic components of the Colorado Green River formation oil shale-Mass spectrometric identification of the methyl esters of extractable acids.

NASA Technical Reports Server (NTRS)

Haug, P.; Schnoes, H. K.; Burlingame, A. L.

1971-01-01

Study of solvent extractable acidic constituents of oil shale from the Colorado Green River Formation. Identification of individual components is based on gas chromatographic and mass spectrometric data obtained for their respective methyl esters. Normal acids, isoprenoidal acids, alpha, omega-dicarboxylic acids, mono-alpha-methyl dicarboxylic acids and methyl ketoacids were identified. In addition, the presence of monocyclic, benzoic, phenylalkanoic and naphthyl-carboxylic acids, as well as cycloaromatic acids, is demonstrated by partial identification.

Effects of altered maternal folic acid, vitamin B12 and docosahexaenoic acid on placental global DNA methylation patterns in Wistar rats.

PubMed

Kulkarni, Asmita; Dangat, Kamini; Kale, Anvita; Sable, Pratiksha; Chavan-Gautam, Preeti; Joshi, Sadhana

2011-03-10

Potential adverse effects of excess maternal folic acid supplementation on a vegetarian population deficient in vitamin B(12) are poorly understood. We have previously shown in a rat model that maternal folic acid supplementation at marginal protein levels reduces brain omega-3 fatty acid levels in the adult offspring. We have also reported that reduced docosahexaenoic acid (DHA) levels may result in diversion of methyl groups towards DNA in the one carbon metabolic pathway ultimately resulting in DNA methylation. This study was designed to examine the effect of normal and excess folic acid in the absence and presence of vitamin B(12) deficiency on global methylation patterns in the placenta. Further, the effect of maternal omega 3 fatty acid supplementation on the above vitamin B(12) deficient diets was also examined. Our results suggest maternal folic acid supplementation in the absence of vitamin B(12) lowers plasma and placental DHA levels (p<0.05) and reduces global DNA methylation levels (p<0.05). When this group was supplemented with omega 3 fatty acids there was an increase in placental DHA levels and subsequently DNA methylation levels revert back to the levels of the control group. Our results suggest for the first time that DHA plays an important role in one carbon metabolism thereby influencing global DNA methylation in the placenta.

Metabolism of aspirin and procaine in mice pretreated with O-4-nitrophenyl methyl(phenyl)phosphinate or O-4-nitrophenyl diphenylphosphinate

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

Joly, J.M.; Brown, T.M.

Concentrations of (carboxyl-/sup 14/C)procaine in blood of mice were increased threefold for 27 min by exposure to O-4-nitrophenyl diphenylphosphinate 2 hr prior to (carboxyl-/sup 14/C)procaine injection ip, while there was no effect of O-4-nitrophenyl methyl(phenyl)phosphinate pretreatment. There was no effect of either organophosphinate on the primary hydrolysis of (acetyl-l-/sup 14/C)aspirin when assessed by the expiration of (/sup 14/C)carbon dioxide; however, O-4-nitrophenyl diphenylphosphinate pretreatment produced transient increases in blood concentrations of both (carboxyl-/sup 14/C)aspirin and (carboxyl-/sup 14/C)salicylic acid following administration of (carboxyl-/sup 14/C)aspirin. Liver carboxylesterase activity in O-4-nitrophenyl diphenylphosphinate pretreated mice was 11% of control activity. These results indicate the potentialmore » for drug interaction with O-4-nitrophenyl diphenylphosphinate but not with O-4-nitrophenyl methyl(phenyl)phosphinate. It appears that liver carboxylesterase activity has a minor role in hydrolysis of aspirin in vivo, but may be more important in procaine metabolism.« less

The occurrence and distribution of uronic acids and sugar methyl ethers in sediment trap materials and sediments of two coastal marine environments

NASA Astrophysics Data System (ADS)

Bergamaschi, Brian A.; Walters, Jeffrey S.; Hedges, John I.

1999-02-01

Although recent research has indicated that bacteria may contribute an important fraction of biochemical residues in terrestrial and marine environments, it is difficult for geochemists to identify contributions from these ubiquitous and biochemically diverse organisms. Previous studies have suggested uronic acids and O-methyl sugars may be useful indicators of microbial abundance and activity, but have been limited primarily to analyses of a small number of isolated samples. We report here comparative distributions of O-methyl sugars, uronic acids, and aldoses in sediment trap material and sediments from Dabob Bay, WA and nearby Saanich Inlet, BC, where temporal and spatial trends may be used together with well-established patterns in other biochemicals to identify bacterial contributions against the background of other carbohydrate sources. O-methyl sugars and uronic acids were important contributors to the overall flux and burial of polysaccharide material in Dabob Bay and Saanich Inlet, composing ≤12 wt% of the total carbohydrate yields from sediment trap and sediment samples. O-methyl sugars accounted for an average of 5% of the carbohydrate yields from sediment trap materials and sediments, but were found rarely and only in low abundance in vascular plant tissues, phytoplankton, and kelp. In contrast, uronic acids were abundant products of sediment trap material and sediments, as well as vascular plant tissues, where in some cases they predominated among all carbohydrates. Uronic acid abundance in sediment trap material averaged 3% and ranged to >6% of total carbohydrate yields. The persistence of total minor sugar yields in water column collections from Dabob Bay throughout the seasonal cycle indicated they had a primary source that was not directly related to plankton bloom cycles nor pulsed inputs of vascular plant remains. Subsurface maxima in total minor sugar yields (and several individual components) within sediment cores from both sites indicate in

On the Origin of the Methyl Radical Loss from Deprotonated Ferulic and Isoferulic Acids: Electronic Excitation of a Transient Structure

NASA Astrophysics Data System (ADS)

Zhang, Xiaoping; Li, Fei; Lv, Huiqing; Wu, Yanqing; Bian, Gaofeng; Jiang, Kezhi

2013-06-01

Formation of radical fragments from even-electron ions is an exception to the "even-electron rule". In this work, ferulic acid (FA) and isoferulic acid (IFA) were used as the model compounds to probe the fragmentation mechanisms and the isomeric effects on homolytic cleavage. Elimination of methyl radical and CO2 are the two competing reactions observed in the CID-MS of [FA - H]- and [IFA - H]-, of which losing methyl radical violates the "even-electron rule". The relative intensity of their product ions is significantly different, and thereby the two isomeric compounds can be differentiated by tandem MS. Theoretical calculations indicate that both the singlet-triplet gap and the excitation energy decrease in the transient structures, as the breaking C-O bond is lengthened. The methyl radical elimination has been rationalized as the intramolecular electronic excitation of a transient structure with an elongating C-O bond. The potential energy diagrams, completed by the addition of the energy barrier of the radical elimination, have provided a reasonable explanation of the different CID-MS behaviors of [FA - H]- and [IFA - H]-.

Comparison of (-)-epigallocatechin-3-O-gallate (EGCG) and O-methyl EGCG bioavailability in rats.

PubMed

Oritani, Yukihiro; Setoguchi, Yuko; Ito, Ryouichi; Maruki-Uchida, Hiroko; Ichiyanagi, Takashi; Ito, Tatsuhiko

2013-01-01

(-)-Epigallocatechin-3-O-(3-O-methyl)gallate (EGCG3″Me) and (-)-epigallocatechin-3-O-(4-O-methyl)gallate (EGCG4″Me) are O-methyl derivatives of (-)-epigallocatechin-3-O-gallate (EGCG) present in tea cultivars such as Benifuuki. Although O-methyl EGCGs have various bioactivities, their bioavailabilities have not been determined. In this study, we compared the bioavailability of EGCG and O-methyl EGCGs in rats, and clarified the pharmacokinetics of O-methyl EGCGs. Following oral administration (100 mg/kg), the areas under the concentration-time curves (AUCs) for EGCG, EGCG3″Me, and EGCG4″Me were 39.6 ± 14.2 µg·h/L, 317.2 ± 43.7 µg·h/L, and 51.9 ± 11.0 µg·h/L, respectively. The AUC after intravenous administration (10 mg/kg) was 2772 ± 480 µg·h/L for EGCG, 8209 ± 549 µg·h/L for EGCG3″Me, and 2465 ± 262 µg·h/L for EGCG4″Me. The bioavailability of EGCG3″Me (0.38%) was the highest (EGCG: 0.14% and EGCG4″Me: 0.21%). The distribution volume of EGCG3″Me (0.26 ± 0.02 L/kg) was the lowest (EGCG: 0.94 ± 0.16 L/kg and EGCG4″Me: 0.93 ± 0.14 L/kg). These results suggested that the higher AUC of EGCG3″Me after oral administration was related to its high bioavailability and low distribution volume. These findings supported the stronger bioactivity of EGCG3″Me in vivo.

CFD simulation of fatty acid methyl ester production in bubble column reactor

NASA Astrophysics Data System (ADS)

Salleh, N. S. Mohd; Nasir, N. F.

2017-09-01

Non-catalytic transesterification is one of the method that was used to produce the fatty acid methyl ester (FAME) by blowing superheated methanol bubbles continuously into the vegetable oil without using any catalyst. This research aimed to simulate the production of FAME from palm oil in a bubble column reactor. Computational Fluid Dynamic (CFD) simulation was used to predict the distribution of fatty acid methyl ester and other product in the reactor. The fluid flow and component of concentration along the reaction time was investigated and the effects of reaction temperature (523 K and 563 K) on the non-catalytic transesterification process has been examined. The study was carried out using ANSYS CFX 17.1. The finding from the study shows that increasing the temperature leads to higher amount of fatty acid methyl ester can be produced in shorter time. On the other hand, concentration of the component such as triglyceride (TG), glycerol (GL) and fatty acid methyl ester (FAME) can be known when reaching the optimum condition.

New bis(alkythio) fatty acid methyl esters

USDA-ARS?s Scientific Manuscript database

The addition reaction of dimethyl disulfide (DMDS) to mono-unsaturated fatty acid methyl esters is well-known for analytical purposes to determine the position of double bonds by mass spectrometry. In this work, the classical iodine-catalyzed reaction is expanded to other dialkyl disulfides (RSSR), ...

Chemical synthesis of guanosine diphosphate mannuronic acid (GDP-ManA) and its C-4-O-methyl and C-4-deoxy congeners.

PubMed

Zhang, Qingju; Howell, P Lynne; Overkleeft, Herman S; Filippov, Dmitri V; van der Marel, Gijsbert A; Codée, Jeroen D C

2017-10-10

Described is the first synthesis of guanosine diphosphate mannuronic acid (GDP-ManA), the sugar donor used by algae and bacteria for the production of alginate, an anionic polysaccharide composed of β-d-mannuronic acid (ManA) and α-l-guluronic acid (GulA). Understanding the biosynthesis of these polyanionic polysaccharides on the molecular level, opens up avenues to use and modulate the biosynthesis machinery for biotechnological and therapeutic applications. The synthesis reported here delivers multi-milligram amounts of the GDP-ManA donor that can be used to study the polymerase (Alg8 in Pseudomonas aeruginosa) that generates the poly-ManA chain. Also reported is the assembly of two close analogues of GDP-ManA: the first bears a C-4-O-methyl group, while the second has been deoxygenated at this position. Both molecules may be used as "chain stoppers" in future enzymatic ManA polymerisation reactions. The crucial pyrophosphate linkage of the GDP-mannuronic acids has been constructed by the phosphorylation of the appropriate ManA-1-phosphates with a guanosine phosphoramidite. Copyright © 2017 Elsevier Ltd. All rights reserved.

2′-O Methylation of Internal Adenosine by Flavivirus NS5 Methyltransferase

PubMed Central

Dong, Hongping; Chang, David C.; Hua, Maggie Ho Chia; Lim, Siew Pheng; Chionh, Yok Hian; Hia, Fabian; Lee, Yie Hou; Kukkaro, Petra; Lok, Shee-Mei; Dedon, Peter C.; Shi, Pei-Yong

2012-01-01

RNA modification plays an important role in modulating host-pathogen interaction. Flavivirus NS5 protein encodes N-7 and 2′-O methyltransferase activities that are required for the formation of 5′ type I cap (m7GpppAm) of viral RNA genome. Here we reported, for the first time, that flavivirus NS5 has a novel internal RNA methylation activity. Recombinant NS5 proteins of West Nile virus and Dengue virus (serotype 4; DENV-4) specifically methylates polyA, but not polyG, polyC, or polyU, indicating that the methylation occurs at adenosine residue. RNAs with internal adenosines substituted with 2′-O-methyladenosines are not active substrates for internal methylation, whereas RNAs with adenosines substituted with N6-methyladenosines can be efficiently methylated, suggesting that the internal methylation occurs at the 2′-OH position of adenosine. Mass spectroscopic analysis further demonstrated that the internal methylation product is 2′-O-methyladenosine. Importantly, genomic RNA purified from DENV virion contains 2′-O-methyladenosine. The 2′-O methylation of internal adenosine does not require specific RNA sequence since recombinant methyltransferase of DENV-4 can efficiently methylate RNAs spanning different regions of viral genome, host ribosomal RNAs, and polyA. Structure-based mutagenesis results indicate that K61-D146-K181-E217 tetrad of DENV-4 methyltransferase forms the active site of internal methylation activity; in addition, distinct residues within the methyl donor (S-adenosyl-L-methionine) pocket, GTP pocket, and RNA-binding site are critical for the internal methylation activity. Functional analysis using flavivirus replicon and genome-length RNAs showed that internal methylation attenuated viral RNA translation and replication. Polymerase assay revealed that internal 2′-O-methyladenosine reduces the efficiency of RNA elongation. Collectively, our results demonstrate that flavivirus NS5 performs 2′-O methylation of internal adenosine of

40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2'-(1,2-diazenediyl)bis[2-methylbutanenitrile]- and 2,2'-(1,2-diazenediyl)bis[2-methylpropanenitrile]-initiated. 721.10326...

Preparation of ErMnO3 by Sol-gel Method and its Photocatalytic Activity for Removal of Methyl Orange from Water

NASA Astrophysics Data System (ADS)

Xie, X. Y.; Yang, J. N.; Yu, L. L.; Min, J. Y.; Sun, D. D.; Tang, P. S.; Chen, H. F.

2018-05-01

The single phase perovskite ErMnO3 was synthesized using Er(NO3)3, manganese acetate, citric acid and urea by a facile sol-gel method. The gel of ErMnO3 precursor was kept for 36 hours in 100 °C oven to get the xerogel. Then, the xerogel was calcined at 800 °C for 12 hours in muffle furnace to prepare single phase ErMnO3. The prepared sample was characterized by thermogravimetry differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Under ultraviolet light, the photocatalytic activity of ErMnO3 was studied with methyl orange of 20 mg/L as the simulated sewage. The results show that the ErMnO3 sample particle size distribution is relatively uniform, the average grain size is mainly around 100 nm. The photocatalytic experiment demonstrates that ErMnO3 is highly photocatalytic activity for removal of methyl orange from water. When methyl orange of 20 mg/L is degraded for 120 min in the presence of ErMnO3, the degradation rate of methyl orange can reach about 95%. The degradation of methyl orange accords with first order kinetic model in presence ErMnO3 sample, and the apparent rate constant is 0.022 min-1.

40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2â²-(1,2-diazenediyl)bis[2-methylbutanenitrile]- and 2,2â²-(1,2-diazenediyl)bis[2-methylpropanenitrile]-initiated. 721.10326...

40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2â²-(1,2-diazenediyl)bis[2-methylbutanenitrile]- and 2,2â²-(1,2-diazenediyl)bis[2-methylpropanenitrile]-initiated. 721.10326...

Vapor Pressure of Methyl Salicylate and n-Hexadecane

DTIC Science & Technology

2014-01-01

VAPOR PRESSURE OF METHYL SALICYLATE AND N-HEXADECANE ECBC-TR-1184 David E. Tevault Leonard C. Buettner...REPORT TYPE Final 3. DATES COVERED (From - To) Mar 2000-Dec 2001 4. TITLE AND SUBTITLE Vapor Pressure of Methyl Salicylate and n-Hexadecane 5a...ABSTRACT Vapor pressure data are reported for O-hydroxybenzoic acid, methyl ester, more commonly known as methyl salicylate (MeS), and n-hexadecane in

Gas chromatography-vacuum ultraviolet spectroscopy for analysis of fatty acid methyl esters.

PubMed

Fan, Hui; Smuts, Jonathan; Bai, Ling; Walsh, Phillip; Armstrong, Daniel W; Schug, Kevin A

2016-03-01

A new vacuum ultraviolet (VUV) detector for gas chromatography was recently developed and applied to fatty acid methyl ester (FAME) analysis. VUV detection features full spectral acquisition in a wavelength range of 115-240nm, where virtually all chemical species absorb. VUV absorption spectra of 37 FAMEs, including saturated, monounsaturated, and polyunsaturated types were recorded. Unsaturated FAMEs show significantly different gas phase absorption profiles than saturated ones, and these classes can be easily distinguished with the VUV detector. Another advantage includes differentiating cis/trans-isomeric FAMEs (e.g. oleic acid methyl ester and linoleic acid methyl ester isomers) and the ability to use VUV data analysis software for deconvolution of co-eluting signals. As a universal detector, VUV also provides high specificity, sensitivity, and a fast data acquisition rate, making it a powerful tool for fatty acid screening when combined with gas chromatography. The fatty acid profile of several food oil samples (olive, canola, vegetable, corn, sunflower and peanut oils) were analyzed in this study to demonstrate applicability to real world samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

Role of N-methyl-2-pyrrolidone for preparation of Fe3O4@SiO2 controlled the shell thickness

NASA Astrophysics Data System (ADS)

Wee, Sung-Bok; Oh, Hyeon-Cheol; Kim, Tae-Gyun; An, Gye-Seok; Choi, Sung-Churl

2017-04-01

We developed a simple and novel approach for the synthesis of Fe3O4@SiO2 nanoparticles with controlled shell thickness, and studied the mechanism. The introduction of N-methyl-2-pyrrolidone (NMP) led to trapping of monomer nuclei in single shell and controlled the shell thickness. Fe3O4@SiO2 controlled the shell thickness, showing a high magnetization value (64.47 emu/g). Our results reveal the role and change in the chemical structure of NMP during the core-shell synthesis process. NMP decomposed to 4-aminobutanoic acid in alkaline condition and decreased the hydrolysis rate of the silica coating process.

A Continuous, Quantitative Fluorescent Assay for Plant Caffeic acid O-Methyltransferases

USDA-ARS?s Scientific Manuscript database

Plant caffeic acid O-methyltransferases (COMTs) use s-adenosylmethionine (ado-met), as a methyl donor to transmethylate their preferred (phenolic) substrates in-vivo, and will generally utilize a range of phenolic compounds in-vitro. Collazo et al. (2005; Analytical Biochemistry 342: 86-92) have pu...

Novel fatty acid methyl esters from the actinomycete Micromonospora aurantiaca

PubMed Central

Bruns, Hilke; Riclea, Ramona

2011-01-01

Summary The volatiles released by Micromonospora aurantiaca were collected by means of a closed-loop stripping apparatus (CLSA) and analysed by GC–MS. The headspace extracts contained more than 90 compounds from different classes. Fatty acid methyl esters (FAMEs) comprised the major compound class including saturated unbranched, monomethyl and dimethyl branched FAMEs in diverse structural variants: Unbranched, α-branched, γ-branched, (ω−1)-branched, (ω−2)-branched, α- and (ω−1)-branched, γ- and (ω−1)-branched, γ- and (ω−2)-branched, and γ- and (ω−3)-branched FAMEs. FAMEs of the last three types have not been described from natural sources before. The structures for all FAMEs have been suggested based on their mass spectra and on a retention index increment system and verified by the synthesis of key reference compounds. In addition, the structures of two FAMEs, methyl 4,8-dimethyldodecanoate and the ethyl-branched compound methyl 8-ethyl-4-methyldodecanoate were deduced from their mass spectra. Feeding experiments with isotopically labelled [2H10]leucine, [2H10]isoleucine, [2H8]valine, [2H5]sodium propionate, and [methyl-2H3]methionine demonstrated that the responsible fatty acid synthase (FAS) can use different branched and unbranched starter units and is able to incorporate methylmalonyl-CoA elongation units for internal methyl branches in various chain positions, while the methyl ester function is derived from S-adenosyl methionine (SAM). PMID:22238549

Interaction between methyl glyoxal and ascorbic acid: experimental and theoretical aspects

NASA Astrophysics Data System (ADS)

Banerjee, D.; Koll, A.; Filarowski, A.; Bhattacharyya, S. P.; Mukherjee, S.

2004-06-01

The absorption spectral change of methyl glyoxal (MG) due to the interaction with ascorbic acid (AA or Vitamin C) has been investigated using steady-state spectroscopic technique. A plausible explanation for the spectral change has been discussed on the basis of hydrogen bonding interaction between the two interacting species. The equilibrium constant for the complex formation due to hydrogen bonding interaction between MG and AA has been obtained from absorption spectral changes. Ab inito calculations with DFT B3LYP/6/31G (d,p) basis sets have been used to find out the molecular structure of the hydrogen bonded complex. The O⋯H distance found in the OH⋯O hydrogen bond turns out to be quite short (1.974 Å) which is in conformity with the large value of the equilibrium constant determined experimentally.

Methylation mediated by an anthocyanin, O-methyltransferase, is involved in purple flower coloration in Paeonia

PubMed Central

Du, Hui; Wu, Jie; Ji, Kui-Xian; Zeng, Qing-Yin; Bhuiya, Mohammad-Wadud; Su, Shang; Shu, Qing-Yan; Ren, Hong-Xu; Liu, Zheng-An; Wang, Liang-Sheng

2015-01-01

Anthocyanins are major pigments in plants. Methylation plays a role in the diversity and stability of anthocyanins. However, the contribution of anthocyanin methylation to flower coloration is still unclear. We identified two homologous anthocyanin O-methyltransferase (AOMT) genes from purple-flowered (PsAOMT) and red-flowered (PtAOMT) Paeonia plants, and we performed functional analyses of the two genes in vitro and in vivo. The critical amino acids for AOMT catalytic activity were studied by site-directed mutagenesis. We showed that the recombinant proteins, PsAOMT and PtAOMT, had identical substrate preferences towards anthocyanins. The methylation activity of PsAOMT was 60 times higher than that of PtAOMT in vitro. Interestingly, this vast difference in catalytic activity appeared to result from a single amino acid residue substitution at position 87 (arginine to leucine). There were significant differences between the 35S::PsAOMT transgenic tobacco and control flowers in relation to their chromatic parameters, which further confirmed the function of PsAOMT in vivo. The expression levels of the two homologous AOMT genes were consistent with anthocyanin accumulation in petals. We conclude that AOMTs are responsible for the methylation of cyanidin glycosides in Paeonia plants and play an important role in purple coloration in Paeonia spp. PMID:26208646

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methyl and ethyl esters of fatty acids produced... Methyl and ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in food, subject to the...

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Methyl and ethyl esters of fatty acids produced... Methyl and ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in food, subject to the...

2-(2-Methyl-4-chlorophenoxy)propionic acid (MCPP)

Integrated Risk Information System (IRIS)

2 - ( 2 - Methyl - 4 - chlorophenoxy ) propionic acid ( MCPP ) ; CASRN 93 - 65 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( H

The fatty acid composition of a Vibrio alginolyticus associated with the alga Cladophora coelothrix. Identification of the novel 9-methyl-10-hexadecenoic acid.

PubMed

Carballeira, N M; Sostre, A; Stefanov, K; Popov, S; Kujumgiev, A; Dimitrova-Konaklieva, S; Tosteson, C G; Tosteson, T R

1997-12-01

The fatty acid composition of a new strain of Vibrio alginolyticus, found in the alga Cladophora coelothrix, was studied. Among 38 different fatty acids, a new fatty acid, 9-methyl-10-hexadecenoic acid and the unusual 11-methyl-12-octadecenoic acid, were identified. Linear alkylbenzene fatty acids, such as 10-phenyldecanoic acid, 12-phenyldodecanoic acid and 14-phenyltetradecanoic acid, were also found in V. alginolyticus. The alga contained 43% saturated fatty acids, and 28% C16-C20 polyunsaturated fatty acids of the n-3 and n-6 families.

Fatty acid methyl ester from Neurospora intermedia N-1 isolated from Indonesian red peanut cake (oncom merah).

PubMed

Priatni, S; Hartati, S; Dewi, P; Kardono, L B S; Singgih, M; Gusdinar, T

2010-08-01

The objective of this study was to identify the Fatty Acid Methyl Ester (FAME) from Neurospora intermedia N-1 that isolated from Indonesian red peanut cake (oncom). FAME profiles have been used as biochemical characters to study many different groups of organisms, such as bacteria and yeasts. FAME from N. intermedia N-1 was obtained by some stages of extraction the orange spores and fractination using a chromatotron. The pure compound (1) was characterized by 500 mHz NMR (1H and 13C), FTIR and LC-MS. Summarized data's of 1H and 13C NMR spectra of compound 1 contained 19 Carbon, 34 Hydrogen and 2 Oxygen (C19H34O2). The position of the double bonds at carbon number 8 and 12 were indicated in the HMBC spectrum (2D-NMR). LC-MS spectrum indicates molecular weight of the compound 1 as 294 which is visible by the presence of protonated molecular ion [M+H] at m/z 295. Methyl esters of long chain fatty acids was presented by a 3 band pattern of IR spectrum with bands near 1249, 1199 and 1172 cm(-1). We suggested that the structure of the pure compound 1 is methyl octadeca-8,12-dienoate. The presence methyl octadeca-8,12-dienoate in N. intermedia is the first report.

Preparation of fatty acid methyl esters for gas-liquid chromatography[S

PubMed Central

Ichihara, Ken'ichi; Fukubayashi, Yumeto

2010-01-01

A convenient method using commercial aqueous concentrated HCl (conc. HCl; 35%, w/w) as an acid catalyst was developed for preparation of fatty acid methyl esters (FAMEs) from sterol esters, triacylglycerols, phospholipids, and FFAs for gas-liquid chromatography (GC). An 8% (w/v) solution of HCl in methanol/water (85:15, v/v) was prepared by diluting 9.7 ml of conc. HCl with 41.5 ml of methanol. Toluene (0.2 ml), methanol (1.5 ml), and the 8% HCl solution (0.3 ml) were added sequentially to the lipid sample. The final HCl concentration was 1.2% (w/v). This solution (2 ml) was incubated at 45°C overnight or heated at 100°C for 1–1.5 h. The amount of FFA formed in the presence of water derived from conc. HCl was estimated to be <1.4%. The yields of FAMEs were >96% for the above lipid classes and were the same as or better than those obtained by saponification/methylation or by acid-catalyzed methanolysis/methylation using commercial anhydrous HCl/methanol. The method developed here could be successfully applied to fatty acid analysis of various lipid samples, including fish oils, vegetable oils, and blood lipids by GC. PMID:19759389

Protective effects of folic acid on DNA damage and DNA methylation levels induced by N-methyl- N'-nitro- N-nitrosoguanidine in Kazakh esophageal epithelial cells.

PubMed

Chen, Y; Feng, H; Chen, D; Abuduwaili, K; Li, X; Zhang, H

2018-01-01

The protective effects of folic acid on DNA damage and DNA methylation induced by N-methyl- N'-nitro- N-nitrosoguanidine (MNNG) in Kazakh esophageal epithelial cells were investigated using a 3 × 3 factorial design trial. The cells were cultured in vitro and exposed to media containing different concentrations of folic acid and MNNG, after which growth indices were detected. DNA damage levels were measured using comet assays, and genome-wide DNA methylation levels (MLs) were measured using high-performance liquid chromatography. The DNA methylation of methylenetetrahydrofolate reductase (MTHFR) and folate receptor- α (FR α) genes was detected by bisulfite sequencing polymerase chain reaction (PCR). The results showed significant increases in tail DNA concentration, tail length, and Olive tail moment ( p < 0.01); a significant reduction of genome-wide DNA MLs ( p < 0.01); and an increase in the methylation frequencies of MTHFR and FR α genes. In particular, significant differences were observed in the promoter regions of both genes ( p < 0.01). Our study indicated that a reduction in folic acid concentration promotes DNA damage and DNA methylation in Kazakh esophageal epithelial cells upon MNNG exposure. Thus, sufficient folic acid levels could play a protective role against the damage induced by this compound.

Folic acid and the methylation of homocysteine by Bacillus subtilis

PubMed Central

Salem, A. R.; Pattison, J. R.; Foster, M. A.

1972-01-01

1. Cell-free extracts of Bacillus subtilis synthesize methionine from serine and homocysteine without added folate. The endogenous folate may be replaced by tetrahydropteroyltriglutamate or an extract of heated Escherichia coli for the overall C1 transfer, but tetrahydropteroylmonoglutamate is relatively inactive. 2. Extracts of B. subtilis contain serine transhydroxymethylase and 5,10-methylenetetrahydrofolate reductase, which are non-specific with respect to the glutamate content of the folate substrates. Methyl transfer to homocysteine requires a polyglutamate folate as methyl donor. These properties are not affected by growth of the organism with added vitamin B12. 3. The synthesis of methionine from 5-methyltetrahydropteroyltriglutamate and homocysteine has the characteristics of the cobalamin-independent reaction of E. coli. No evidence for a cobalamin-dependent transmethylation was obtained. 4. S-Adenosylmethionine was not a significant precursor of the methyl group of methionine with cell-free extracts, neither was S-adenosylmethionine generated by methylation of S-adenosylhomocysteine by 5-methyltetrahydrofolate. 5. A procedure for the isolation and analysis of folic acid derivatives from natural sources is described. 6. The folates isolated from lysozyme extracts of B. subtilis are sensitive to folic acid conjugase. One has been identified as 5-formyltetrahydropteroyltriglutamate; the other is possibly a diglutamate folate. 7. A sequence is proposed for methionine biosynthesis in B. subtilis in which methyl groups are generated from serine and transferred to homocysteine by means of a cobalamin-independent pathway mediated by conjugated folate coenzymes. PMID:4627401

Effective methylation of phosphonic acids related to chemical warfare agents mediated by trimethyloxonium tetrafluoroborate for their qualitative detection and identification by gas chromatography-mass spectrometry

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

Valdez, Carlos A.; Leif, Roald N.; Alcaraz, Armando

The effective methylation of phosphonic acids related to chemical warfare agents (CWAs) employing trimethyloxonium tetrafluoroborate (TMO·BF 4) for their qualitative detection and identification by gas chromatography-mass spectrometry (GC-MS) is presented. The methylation occurs in rapid fashion (1 h) and can be conveniently carried out at ambient temperature, thus providing a safer alternative to the universally employed diazomethane-based methylation protocols. Optimization of the methylation parameters led us to conclude that methylene chloride was the ideal solvent to carry out the derivatization, and that even though methylated products can be observed surfacing after only 1 h, additional time was not found tomore » be detrimental but beneficial to the process particularly when dealing with analytes at low concentrations (~10 μg mL -1). Due to its insolubility in methylene chloride, TMO·BF 4 conveniently settles to the bottom during the reaction and does not produce additional interfering by-products that may further complicate the GC-MS analysis. We demonstrated the method to successfully methylate a variety of Schedule 2 phosphonic acids, including their half esters, resulting in derivatives that were readily detected and identified using the instrument's spectral library. Most importantly, the method was shown to simultaneously methylate a mixture of the organophosphorus-based nerve agent hydrolysis products: pinacolyl methylphosphonate (PMPA), cyclohexyl methylphosphonate (CyMPA) and ethyl methylphosphonate (EMPA) (at a 10 μg mL -1 concentration each) in a fatty acid ester-rich organic matrix (OPCW-PT-O 3) featured in the 38th Organisation for the Prohibition of Chemical Weapons (OPCW) Proficiency Test. Additionally, the protocol was found to effectively methylate N,N-diethylamino ethanesulfonic acid and N,N-diisopropylamino ethanesulfonic acid that are products arising from the oxidative degradation of the V-series agents VR and VX respectively

Effective methylation of phosphonic acids related to chemical warfare agents mediated by trimethyloxonium tetrafluoroborate for their qualitative detection and identification by gas chromatography-mass spectrometry

DOE PAGES

Valdez, Carlos A.; Leif, Roald N.; Alcaraz, Armando

2016-06-01

The effective methylation of phosphonic acids related to chemical warfare agents (CWAs) employing trimethyloxonium tetrafluoroborate (TMO·BF 4) for their qualitative detection and identification by gas chromatography-mass spectrometry (GC-MS) is presented. The methylation occurs in rapid fashion (1 h) and can be conveniently carried out at ambient temperature, thus providing a safer alternative to the universally employed diazomethane-based methylation protocols. Optimization of the methylation parameters led us to conclude that methylene chloride was the ideal solvent to carry out the derivatization, and that even though methylated products can be observed surfacing after only 1 h, additional time was not found tomore » be detrimental but beneficial to the process particularly when dealing with analytes at low concentrations (~10 μg mL -1). Due to its insolubility in methylene chloride, TMO·BF 4 conveniently settles to the bottom during the reaction and does not produce additional interfering by-products that may further complicate the GC-MS analysis. We demonstrated the method to successfully methylate a variety of Schedule 2 phosphonic acids, including their half esters, resulting in derivatives that were readily detected and identified using the instrument's spectral library. Most importantly, the method was shown to simultaneously methylate a mixture of the organophosphorus-based nerve agent hydrolysis products: pinacolyl methylphosphonate (PMPA), cyclohexyl methylphosphonate (CyMPA) and ethyl methylphosphonate (EMPA) (at a 10 μg mL -1 concentration each) in a fatty acid ester-rich organic matrix (OPCW-PT-O 3) featured in the 38th Organisation for the Prohibition of Chemical Weapons (OPCW) Proficiency Test. Additionally, the protocol was found to effectively methylate N,N-diethylamino ethanesulfonic acid and N,N-diisopropylamino ethanesulfonic acid that are products arising from the oxidative degradation of the V-series agents VR and VX respectively

[Inhibition of oxidation of unsaturated fatty acid methyl esters by essential oils].

PubMed

Misharina, T A; Alinkina, E S; Vorobjeva, A K; Terenina, M B; Krikunova, N I

2016-01-01

The essential oils from 16 various spice plants were studied as natural antioxidants for the inhibition of autooxidation of polyunsaturated fatty acids methyl esters isolated from linseed oil. The content of methyl oleate, methyl linoleate, and methyl linolenoate after 1, 2, and 4 months of autooxidation were used as criteria to estimate the antioxidant efficiencies of essential oils. In 4 months, 92% of the methyl linolenoate and 79% of the methyl linoleate were oxidized in a control sample of a model system. It was found that the most effective antioxidants were essential oils from clove bud, cinnamon leaves, and oregano. They inhibited autooxidation of methyl linolenoate by 76–85%. The antioxidant properties of these essential oils were due to phenols— eugenol, carvacrol, and thymol. Essential oil from coriander did not contain phenols, but it inhibited methyl linolenoate oxidation by 38%. Essential oils from thyme, savory, mace, lemon, and tea tree inhibited methyl linolenoate oxidation by 17–24%. The other essential oils had no antioxidant properties.

PLASMID DNA DAMAGE CAUSED BY METHYLATED ARSENICALS, ASCORBIC ACID AND HUMAN LIVER FERRITIN

EPA Science Inventory

PLASMID DNA DAMAGE CAOUSED BY METHYLATED ARSENICALS, ASCORBIC ACID AND HUMAN LIVER FERRITIN

ABSTRACT

Both dimethylarsinic acid (DMA(V)) and dimethylarsinous acid (DMA(III)) release iron from human liver ferritin (HLF) with or without the presence of ascorbic acid. ...

Formation of O2-methylthymine in poly(dA-dT) on methylation with N-methyl-N-nitrosourea and dimethyl sulphate. Evidence that O2-methylthymine does not miscode during DNA synthesis.

PubMed Central

Saffhill, R; Abbott, P J

1978-01-01

The alternating co-polymer has been methylated with either N methyl-N-nitrosourea (MNU) or dimethyl sulphate (DMS) and the levels of the various methylated thymidines (O2-methylthymidine, 3-methylthymidine and O4-methylthymidine) measured. MNU produced all three compounds whereas DMS only produced 3-methylthymidine and O2-methylthymidine at detectable levels. These results have been combined with our earlier results concerning the misincorporation of dGMP with E. coli DNA polymerase using MNU-methylated poly(dA-dT). These results indicate that O2-methylthymidine does not miscode during DNA synthesis. PMID:353735

Thermal Decomposition of Potential Ester Biofuels. Part I: Methyl Acetate and Methyl Butanoate

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

Porterfield, Jessica P.; Bross, David H.; Ruscic, Branko

2017-06-09

Two methyl esters have been examined as models for the pyrolysis of biofuels. Dilute samples (0.06 - 0.13%) of methyl acetate (CH 3COOCH 3) and methyl butanoate (CH 3CH 2CH 2COOCH 3) were entrained in (He, Ar) carrier gas and decomposed in a set of flash-pyrolysis micro-reactors. The pyrolysis products resulting from the methyl esters were detected and identified by vacuum ultraviolet photoionization mass spectrometry. Complementary product identification was provided by matrix infrared absorption spectroscopy. Pyrolysis pressures in the pulsed micro-reactor were roughly 20 Torr and residence times through the reactors were approximately 25 - 150 µs. Reactor temperatures ofmore » 300 – 1600 K were explored. Decomposition of CH 3COOCH 3 commences at 1000 K and the initial products are (CH 2=C=O and CH 3OH). As the micro-reactor is heated to 1300 K, a mixture of (CH 2=C=O and CH 3OH, CH 3, CH 2=O, H, CO, CO 2) appears. The thermal cracking of CH 3CH 2CH 2COOCH 3 begins at 800 K with the formation of (CH 3CH 2CH=C=O, CH 3OH). By 1300 K, the pyrolysis of methyl butanoate yields a complex mixture of (CH 3CH 2CH=C=O, CH 3OH, CH 3, CH 2=O, CO, CO 2, CH 3CH=CH 2, CH 2CHCH 2, CH 2=C=CH 2, HCCCH 2, CH 2=C=C=O, CH 2=CH 2, HCΞCH, CH 2=C=O). Based on the results from the thermal cracking of methyl acetate and methyl butanoate, we predict several important decomposition channels for the pyrolysis of fatty acid methyl esters, R CH 2-COOCH 3. The lowest energy fragmentation will be a 4-center elimination of methanol to form the ketene, RCH=C=O. At higher temperatures, concerted fragmentation to radicals will ensue to produce a mixture of species: (RCH 2 + CO 2 + CH 3) and (RCH 2 + CO + CH 2=O + H). Thermal cracking of the β C-C bond of the methyl ester will generate the radicals (R and H) as well as CH 2=C=O + CH 2=O. The thermochemistry of methyl acetate and its fragmentation products have been obtained via the Active Thermochemical Tables (ATcT) approach, resulting in �

Crystal structure of di­methyl­ammonium hydrogen oxalate hemi(oxalic acid)

PubMed Central

Diallo, Waly; Gueye, Ndongo; Crochet, Aurélien; Plasseraud, Laurent; Cattey, Hélène

2015-01-01

Single crystals of the title salt, Me2NH2 +·HC2O4 −·0.5H2C2O4, were isolated as a side product from the reaction involving Me2NH, H2C2O4 and Sn(n-Bu)3Cl in a 1:2 ratio in methanol or by the reaction of the (Me2NH2)2C2O4 salt and Sn(CH3)3Cl in a 2:1 ratio in ethanol. The asymmetric unit comprises a di­methyl­ammonium cation (Me2NH2 +), an hydrogenoxalate anion (HC2O4 −), and half a mol­ecule of oxalic acid (H2C2O4) situated about an inversion center. From a supra­molecular point of view, the three components inter­act together via hydrogen bonding. The Me2NH2 + cations and the HC2O4 − anions are in close proximity through bifurcated N—H⋯(O,O) hydrogen bonds, while the HC2O4 − anions are organized into infinite chains via O—H⋯O hydrogen bonds, propagating along the a-axis direction. In addition, the oxalic acid (H2C2O4) mol­ecules play the role of connectors between these chains. Both the carbonyl and hydroxyl groups of each diacid are involved in four inter­molecular inter­actions with two Me2NH2 + and two HC2O4 − ions of four distinct polymeric chains, via two N—H⋯O and two O—H⋯O hydrogen bonds, respectively. The resulting mol­ecular assembly can be viewed as a two-dimensional bilayer-like arrangement lying parallel to (010), and reinforced by a C—H⋯O hydrogen bond. PMID:25995858

Glucuronoyl esterases are active on polymeric substrate, methyl esterified glucuronoxylan

USDA-ARS?s Scientific Manuscript database

Alkali extracted beechwood glucuronoxylan methyl ester prepared by esterification of 4-O-methyl-D-glucuronic acid side residues by methanol was found to serve as substrate of microbial glucuronoyl esterases from Ruminococcus flavefaciens, Schizophyllum commune and Trichoderma reesei. The enzymatic d...

Supra-physiological folic acid concentrations induce aberrant DNA methylation in normal human cells in vitro.

PubMed

Charles, Michelle A; Johnson, Ian T; Belshaw, Nigel J

2012-07-01

The micronutrients folate and selenium may modulate DNA methylation patterns by affecting intracellular levels of the methyl donor S-adenosylmethionine (SAM) and/or the product of methylation reactions S-adenosylhomocysteine (SAH). WI-38 fibroblasts and FHC colon epithelial cells were cultured in the presence of two forms of folate or four forms of selenium at physiologically-relevant doses, and their effects on LINE-1 methylation, gene-specific CpG island (CGI) methylation and intracellular SAM:SAH were determined. At physiologically-relevant doses the forms of folate or selenium had no effect on LINE-1 or CGI methylation, nor on intracellular SAM:SAH. However the commercial cell culture media used for the selenium studies, containing supra-physiological concentrations of folic acid, induced LINE-1 hypomethylation, CGI hypermethylation and decreased intracellular SAM:SAH in both cell lines. We conclude that the exposure of normal human cells to supra-physiological folic acid concentrations present in commercial cell culture media perturbs the intracellular SAM:SAH ratio and induces aberrant DNA methylation.

Anti-arthritic activity of 11-O-(4'-O-methyl galloyl)-bergenin and Crassula capitella extract in rats.

PubMed

El-Hawary, Seham S; Mohammed, Rabab; Abouzid, Sameh; Ali, Zeinab Y; Elwekeel, Ahlam

2016-06-01

Isolation and identification of phytochemicals of Crassula capitella (Thunberg), evaluation of the anti-arthritic potential of the extract and the major isolated compound; 11-O-(4'-O-methyl galloyl)-bergenin and underlying their mechanism on rat model of rheumatoid arthritis (RA). Different fractions were subjected to column chromatography giving fourteen compound identified by mass and NMR spectroscopic techniques. RA was induced by intraplantar injection of complete Freund's adjuvant into the right hind paw of rats. Influence of tested samples in comparable to methotrexate on paw oedema, body weight gain, serum diagnostic markers, cartilage and bone degeneration enzymes, pro-inflammatory mediators and oxidative stress biomarkers in arthritic rats. Fourteen phenolic compounds were isolated and identified for the first time from C. capitella. The major compound identified as 11-O-(4'-O-methyl galloyl)-bergenin. Treatment of arthritic rats with extract or 11-O-(4'-O-methyl galloyl)-bergenin with the tested doses can reduce the progression and severity of RA. Crassula capitella is a new natural and abundant source for 11-O-(4'-O-methyl galloyl)-bergenin for resolving chronic inflammatory diseases as RA through antioxidant, anti-inflammatory and membrane stabilizing mechanism. © 2016 Royal Pharmaceutical Society.

Effects of high-melting methyl esters on crystallization properties of fatty acid methyl ester mixtures

USDA-ARS?s Scientific Manuscript database

Biodiesel is a renewable alternative diesel fuel made from vegetable oils and animal fats. The most common form of biodiesel in the United States are fatty acid methyl esters (FAME) from soybean, canola, and used cooking oils, waste greases, and tallow. Cold flow properties of biodiesel depend on th...

40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.

Code of Federal Regulations, 2011 CFR

2011-07-01

... New Uses for Specific Chemical Substances § 721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino... substance identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester (PMN P-85-1211) is subject... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Benzoic acid, 2-(3-phenylbutylidene...

40 CFR 721.1728 - Benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester.

Code of Federal Regulations, 2010 CFR

2010-07-01

... New Uses for Specific Chemical Substances § 721.1728 Benzoic acid, 2-(3-phenylbutylidene)amino... substance identified as benzoic acid, 2-(3-phenylbutylidene)amino-, methyl ester (PMN P-85-1211) is subject... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Benzoic acid, 2-(3-phenylbutylidene...

Effect of postharvest methyl jasmonate treatment on fatty acid composition and phenolic acid content in olive fruits during storage.

PubMed

Flores, Gema; Blanch, Gracia Patricia; Del Castillo, María Luisa Ruiz

2017-07-01

The nutritional effects of both table olives and olive oil are attributed not only to their fatty acids but also to antioxidant phenolics such as phenolic acids. Delays in oil processing usually result in undesirable oxidation and hydrolysis processes leading to formation of free fatty acids. These alterations create the need to process oil immediately after olive harvest. However, phenolic content decreases drastically during olive storage resulting in lower quality oil. In the present study we propose postharvest methyl jasmonate treatment as a mean to avoid changes in fatty acid composition and losses of phenolic acids during olive storage. Contents of fatty acids and phenolic acids were estimated in methyl jasmonate treated olives throughout 30-day storage, as compared with those of untreated olives. Significant decreases of saturated fatty acids were observed in treated samples whereas increases of oleic, linoleic and linolenic acids were respectively measured (i.e. from 50.8% to 64.5%, from 7.2% to 9.1% and from 1.5% to 9.3%). Also, phenolic acid contents increased significantly in treated olives. Particularly, increases of gallic acid from 1.35 to 6.29 mg kg -1 , chlorogenic acid from 9.18 to 16.21 mg kg -1 , vanillic acid from 9.61 to 16.99 mg kg -1 , caffeic acid from 5.12 to 12.55 mg kg -1 , p-coumaric acid from 0.96 to 5.31 mg kg -1 and ferulic acid from 4.05 to 10.43 mg kg -1 were obtained. Methyl jasmonate treatment is proposed as an alternative postharvest technique to traditional methods to guarantee olive oil quality when oil processing is delayed and olive fruits have to necessarily to be stored. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

O-(Triazolyl)methyl carbamates as a novel and potent class of FAAH inhibitors

PubMed Central

Colombano, Giampiero; Albani, Clara; Ottonello, Giuliana; Ribeiro, Alison; Scarpelli, Rita; Tarozzo, Glauco; Daglian, Jennifer; Jung, Kwang-Mook; Piomelli, Daniele; Bandiera, Tiziano

2015-01-01

Inhibition of fatty acid amide hydrolase (FAAH) activity is under investigation as a valuable strategy for the treatment of several disorders, including pain and drug addiction. A number of potent FAAH inhibitors belonging to different chemical classes have been disclosed. O-aryl carbamates are one of the most representative families. In the search for novel FAAH inhibitors, we synthesized a series of O-(1,2,3-triazol-4-yl)methyl carbamate derivatives exploiting the copper-catalyzed [3 + 2] cycloaddition reaction between azides and alkynes (click chemistry). We explored structure-activity relationships within this new class of compounds and identified potent inhibitors of both rat and human FAAH with IC50 values in the single-digit nanomolar range. PMID:25338703

Cyclic mu-opioid receptor ligands containing multiple N-methylated amino acid residues.

PubMed

Adamska-Bartłomiejczyk, Anna; Janecka, Anna; Szabó, Márton Richárd; Cerlesi, Maria Camilla; Calo, Girolamo; Kluczyk, Alicja; Tömböly, Csaba; Borics, Attila

2017-04-15

In this study we report the in vitro activities of four cyclic opioid peptides with various sequence length/macrocycle size and N-methylamino acid residue content. N-Methylated amino acids were incorporated and cyclization was employed to enhance conformational rigidity to various extent. The effect of such modifications on ligand structure and binding properties were studied. The pentapeptide containing one endocyclic and one exocyclic N-methylated amino acid displayed the highest affinity to the mu-opioid receptor. This peptide was also shown to be a full agonist, while the other analogs failed to activate the mu opioid receptor. Results of molecular docking studies provided rationale for the explanation of binding properties on a structural basis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Radiosynthesis of N-¹¹C-Methyl-Taurine-Conjugated Bile Acids and Biodistribution Studies in Pigs by PET/CT.

PubMed

Schacht, Anna Christina; Sørensen, Michael; Munk, Ole Lajord; Frisch, Kim

2016-04-01

During cholestasis, accumulation of conjugated bile acids may occur in the liver and lead to hepatocellular damage. Inspired by our recent development of N-(11)C-methyl-glycocholic acid-that is, (11)C-cholylsarcosine-a tracer for PET of the endogenous glycine conjugate of cholic acid, we report here a radiosynthesis of N-(11)C-methyl-taurine-conjugated bile acids and biodistribution studies in pigs by PET/CT. A radiosynthesis of N-(11)C-methyl-taurine-conjugated bile acids was developed and used to prepare N-(11)C-methyl-taurine conjugates derived from cholic, chenodeoxycholic, deoxycholic, ursodeoxycholic, and lithocholic acid. The lipophilicity of these new tracers was determined by reversed-phase thin-layer chromatography. The effect of lipophilicity and structure on the biodistribution was investigated in pigs by PET/CT using the tracers derived from cholic acid (3α-OH, 7α-OH, 12α-OH), ursodeoxycholic acid (3α-OH, 7β-OH), and lithocholic acid (3α-OH). The radiosyntheses of the N-(11)C-methyl-taurine-conjugated bile acids proceeded with radiochemical yields of 61% (decay-corrected) or greater and radiochemical purities greater than 99%. PET/CT in pigs revealed that the tracers were rapidly taken up by the liver and secreted into bile. There was no detectable radioactivity in urine. Significant reflux of N-(11)C-methyl-taurolithocholic acid into the stomach was observed. We have successfully developed a radiosynthesis of N-(11)C-methyl-taurine-conjugated bile acids. These tracers behave in a manner similar to endogenous taurine-conjugated bile acids in vivo and are thus promising for functional PET of patients with cholestatic diseases. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Methylenetetrahydrofolate Reductase Modulates Methyl Metabolism and Lignin Monomer Methylation in Maize.

PubMed

Wu, Zhenying; Ren, Hao; Xiong, Wangdan; Roje, Sanja; Liu, Yuchen; Su, Kunlong; Fu, Chunxiang

2018-05-30

The brown midrib2 (bm2) mutant of maize, with a modified lignin composition, contains a mutation in the methylenetetrahydrofolate reductase (MTHFR) gene. We here show that a MITE transposon insertion caused downregulation of MTHFR with accompanying decrease in 5-methyl-THF and increase in 5, 10-methylene-THF and THF in the bm2 mutant. Furthermore, MTHFR mutation did not change the content of SAM, the methyl group donor involved in the biosynthesis of guaiacyl (G) and syringyl (S) lignins, but increased the level of S-adenosyl homocysteine (SAH), the de-methylation product of SAM. Moreover, competitive inhibition of the maize caffeoyl CoA O-methyltransferase (CCoAOMT) and caffeic acid O-methyltransferase (COMT) enzyme activities by SAH was found, suggesting that SAH/SAM ratio rather than SAM concentration regulates the transmethylation reactions of lignin intermediates. Phenolic profiling revealed that caffeoyl alcohol glucose derivatives accumulated in the mutant, indicating impaired 3-O-methylation of monolignols. A remarkable increase in the unusual catechyl (C) lignin determined in the mutant demonstrates that MTHFR downregulation mainly affects G lignin biosynthesis, consistent with the observation that CCoAOMT is more sensitive to SAH inhibition than COMT. This study which uncovered a novel regulatory mechanism in lignin biosynthesis and may offer an effective approach to utilize lignocellulosic feedstocks in future.

Effective methylation of phosphonic acids related to chemical warfare agents mediated by trimethyloxonium tetrafluoroborate for their qualitative detection and identification by gas chromatography-mass spectrometry.

PubMed

Valdez, Carlos A; Leif, Roald N; Alcaraz, Armando

2016-08-24

The effective methylation of phosphonic acids related to chemical warfare agents (CWAs) employing trimethyloxonium tetrafluoroborate (TMO·BF4) for their qualitative detection and identification by gas chromatography-mass spectrometry (GC-MS) is presented. The methylation occurs in rapid fashion (1 h) and can be conveniently carried out at ambient temperature, thus providing a safer alternative to the universally employed diazomethane-based methylation protocols. Optimization of the methylation parameters led us to conclude that methylene chloride was the ideal solvent to carry out the derivatization, and that even though methylated products can be observed surfacing after only 1 h, additional time was not found to be detrimental but beneficial to the process particularly when dealing with analytes at low concentrations (∼10 μg mL(-1)). Due to its insolubility in methylene chloride, TMO·BF4 conveniently settles to the bottom during the reaction and does not produce additional interfering by-products that may further complicate the GC-MS analysis. The method was demonstrated to successfully methylate a variety of Schedule 2 phosphonic acids, including their half esters, resulting in derivatives that were readily detected and identified using the instrument's spectral library. Most importantly, the method was shown to simultaneously methylate a mixture of the organophosphorus-based nerve agent hydrolysis products: pinacolyl methylphosphonate (PMPA), cyclohexyl methylphosphonate (CyMPA) and ethyl methylphosphonate (EMPA) (at a 10 μg mL(-1) concentration each) in a fatty acid ester-rich organic matrix (OPCW-PT-O3) featured in the 38th Organisation for the Prohibition of Chemical Weapons (OPCW) Proficiency Test. In addition, the protocol was found to effectively methylate N,N-diethylamino ethanesulfonic acid and N,N-diisopropylamino ethanesulfonic acid that are products arising from the oxidative degradation of the V-series agents VR and VX respectively. The

Methyl-branched fatty acids, inhibitors of enoyl-ACP reductase with antibacterial activity from Streptomyces sp. A251.

PubMed

Zheng, Chang-Ji; Sohn, Mi-Jin; Chi, Seung-Wook; Kim, Won-Gon

2010-05-01

Bacterial enoyl-ACP reductase (FabI) has been demonstrated to be a novel antibacterial target. In the course of our screening for FabI inhibitors we isolated two methyl-branched fatty acids from Streptomyces sp. A251. They were identified as 14-methyl-9(Z)-pentadecenoic acid and 15-methyl-9(Z)-hexadecenoic acid by MS and NMR spectral data. These compounds inhibited Staphylococcus aureus FabI with IC50 of 16.0 and 16.3mu M, respectively, while didn't affect FabK, an enoyl-ACP reductase of Streptococcus pneumonia, at 100muM. Consistent with their selective inhibition for FabI, they blocked intracellular fatty acid synthesis as well as the growth of S. aureus, while didn't inhibit the growth of S. pneumonia. Additionally, these compounds showed reduced antibacterial activity against fabI-overexpressing S. aureus compared to the wild-type strain. These results demonstrate that the methyl-branched fatty acids showed antibacterial activity by inhibiting FabI in vivo.

Mitochondrial biotransformation of ω-(phenoxy)alkanoic acids, 3-(phenoxy)acrylic acids, and ω-(1-methyl-1H-imidazol-2-ylthio)alkanoic acids: A prodrug strategy for targeting cytoprotective antioxidants to mitochondria

PubMed Central

Roser, Kurt S.; Brookes, Paul S.; Wojtovich, Andrew P.; Olson, Leif P.; Shojaie, Jalil; Parton, Richard L.; Anders, M. W.

2010-01-01

Mitochondrial reactive oxygen species (ROS) generation and the attendant mitochondrial dysfunction are implicated in a range of disease states. The objective of the present studies was to test the hypothesis that the mitochondrial β-oxidation pathway could be exploited to deliver and biotransform the prodrugs ω-(phenoxy)alkanoic acids, 3-(phenoxy)acrylic acids, and ω-(1-methyl-1H-imidazol-2-ylthio)alkanoic acids to the corresponding phenolic antioxidants or methimazole. 3 -and 5-(Phenoxy)alkanoic acids and methyl-substituted analogs were biotransformed to phenols; rates of biotransformation decreased markedly with methyl-group substitution on the phenoxy moiety. 2,6-Dimethylphenol formation from the analogs 3-([2,6-dimethylphenoxy]methylthio)propanoic acid and 3-(2,6-dimethylphenoxy)acrylic acid was greater than that observed with ω-(2,6-dimethylphenoxy)alkanoic acids. 3- and 5-(1-Methyl-1H-imidazol-2-ylthio)alkanoic acids were rapidly biotransformed to the antioxidant methimazole and conferred significant cytoprotection against hypoxia-reoxygenation injury in isolated cardiomyocytes. Both 3-(2,6-dimethylphenoxy)propanoic acid and 3-(2,6-dimethylphenoxy)acrylic acid also afforded cytoprotection against hypoxia-reoxygenation injury in isolated cardiomyocytes. These results demonstrate that mitochondrial β-oxidation is a potentially useful delivery system for targeting antioxidants to mitochondria. PMID:20129794

40 CFR 721.10136 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl...

Code of Federal Regulations, 2010 CFR

2010-07-01

...-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl)melamine (generic). 721.10136 Section 721.10136... 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl... substance identified generically as 2-propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products...

40 CFR 721.10136 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl...

Code of Federal Regulations, 2011 CFR

2011-07-01

...-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl)melamine (generic). 721.10136 Section 721.10136... 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products with hexakis(alkoxyalkyl... substance identified generically as 2-propenoic acid, 2-methyl-, 2-hydroxyethyl ester, reaction products...

A 2:1 co-crystal of 2-methyl-benzoic acid and N,N'-bis-(pyridin-4-ylmeth-yl)ethanedi-amide: crystal structure and Hirshfeld surface analysis.

PubMed

Syed, Sabrina; Jotani, Mukesh M; Halim, Siti Nadiah Abdul; Tiekink, Edward R T

2016-03-01

The asymmetric unit of the title 2:1 co-crystal, 2C8H8O2·C14H14N4O2, comprises an acid mol-ecule in a general position and half a di-amide mol-ecule, the latter being located about a centre of inversion. In the acid, the carb-oxy-lic acid group is twisted out of the plane of the benzene ring to which it is attached [dihedral angle = 28.51 (8)°] and the carbonyl O atom and methyl group lie approximately to the same side of the mol-ecule [hy-droxy-O-C-C-C(H) torsion angle = -27.92 (17)°]. In the di-amide, the central C4N2O2 core is almost planar (r.m.s. deviation = 0.031 Å), and the pyridyl rings are perpendicular, lying to either side of the central plane [central residue/pyridyl dihedral angle = 88.60 (5)°]. In the mol-ecular packing, three-mol-ecule aggregates are formed via hy-droxy-O-H⋯N(pyrid-yl) hydrogen bonds. These are connected into a supra-molecular layer parallel to (12[Formula: see text]) via amide-N-H⋯O(carbon-yl) hydrogen bonds, as well as methyl-ene-C-H⋯O(amide) inter-actions. Significant π-π inter-actions occur between benzene/benzene, pyrid-yl/benzene and pyrid-yl/pyridyl rings within and between layers to consolidate the three-dimensional packing.

Application of ethyl esters and d3-methyl esters as internal standards for the gas chromatographic quantification of transesterified fatty acid methyl esters in food.

PubMed

Thurnhofer, Saskia; Vetter, Walter

2006-05-03

Ethyl esters (FAEE) and trideuterium-labeled methyl esters (d3-FAME) of fatty acids were prepared and investigated regarding their suitability as internal standards (IS) for the determination of fatty acids as methyl esters (FAME). On CP-Sil 88, ethyl esters of odd-numbered fatty acids eluted approximately 0.5 min after the respective FAME, and only coelutions with minor FAME were observed. Depending on the problem, one or even many FAEE can be added as IS for the quantification of FAME by both GC-FID and GC-MS. By contrast, d3-FAME coeluted with FAME on the polar GC column, and the use of the former as IS requires application of GC-MS. In the SIM mode, m/z 77 and 90 are suggested for d3-methyl esters of saturated fatty acids, whereas m/z 88 and 101 are recommended for ethyl esters of saturated fatty acids. These m/z values give either no or very low response for FAME and can thus be used for the analysis of FAME in food by GC-MS in the SIM mode. Fatty acids in sunflower oil and mozzarella cheese were quantified using five saturated FAEE as IS. Gravimetric studies showed that the transesterification procedure could be carried out without of loss of fatty acids. GC-EI/MS full scan analysis was suitable for the quantitative determination of all unsaturated fatty acids in both food samples, whereas GC-EI/MS in the SIM mode was particularly valuable for quantifying minor fatty acids. The novel GC-EI/MS/SIM method using fatty acid ethyl esters as internal standards can be used to quantify individual fatty acids only, that is, without determination of all fatty acids (the common 100% method), although this is present. This was demonstrated by the exclusive quantification of selected fatty acids including methyl-branched fatty acids, erucic acid (18:1n-9trans), and polyunsaturated fatty acids in cod liver oil and goat's milk fat.

Radiation chemistry of salicylic and methyl substituted salicylic acids: Models for the radiation chemistry of pharmaceutical compounds

NASA Astrophysics Data System (ADS)

Ayatollahi, Shakiba; Kalnina, Daina; Song, Weihua; Turks, Maris; Cooper, William J.

2013-11-01

Salicylic acid and its derivatives are components of many medications and moieties found in numerous pharmaceutical compounds. They have been used as models for various pharmaceutical compounds in pharmacological studies, for the treatment of pharmaceuticals and personal care products (PPCPs), and, reactions with natural organic matter (NOM). In this study, the radiation chemistry of benzoic acid, salicylic acid and four methyl substituted salicylic acids (MSA) is reported. The absolute bimolecular reaction rate constants for hydroxyl radical reaction with benzoic and salicylic acids as well as 3-methyl-, 4-methyl-, 5-methyl-, and 6-methyl-salicylic acid were determined (5.86±0.54)×109, (1.07±0.07)×1010, (7.48±0.17)×109, (7.31±0.29)×109, (5.47±0.25)×109, (6.94±0.10)×109 (M-1 s-1), respectively. The hydrated electron reaction rate constants were measured (3.02±0.10)×109, (8.98±0.27)×109, (5.39±0.21)×109, (4.33±0.17)×109, (4.72±0.15)×109, (1.42±0.02)×109 (M-1 s-1), respectively. The transient absorption spectra for the six model compounds were examined and their role as model compounds for the radiation chemistry of pharmaceuticals investigated.

40 CFR 721.1725 - Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Significant New Uses for Specific Chemical Substances § 721.1725 Benzoic acid, 3,3′-methyl-enebis [6 amino..., Benzoic acid, 3,3′-methylenebis [6 amino-, di-2-propenyl ester. (2) The significant new uses are: (i) Any... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Benzoic acid, 3,3â²-methyl-enebis [6...

40 CFR 721.1725 - Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Significant New Uses for Specific Chemical Substances § 721.1725 Benzoic acid, 3,3′-methyl-enebis [6 amino..., Benzoic acid, 3,3′-methylenebis [6 amino-, di-2-propenyl ester. (2) The significant new uses are: (i) Any... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Benzoic acid, 3,3â²-methyl-enebis [6...

The vibrational spectra and structure of 4-methyl oxaloacetate (carbomethoxypyruvic acid)

NASA Astrophysics Data System (ADS)

Schiering, David W.; Katon, J. E.

1986-04-01

The vibrational spectra of solid 4-methyl oxalocetate have been recorded. Infrared spectra were collected at ambient and liquid nitrogen temperatures; Raman spectra were collected at ambient temperature only. A tentative vibrational assignment of the solid is proposed based on a dimer structure composed of two enolic monomer units hydrogen bonded through the carboxylic acid group. 4-Methyl oxaloacetate was found to undergo keto—enol tautomerization in solution, and the solvent dependency of this equilibrium was demonstrated.

Production of 7-O-Methyl Aromadendrin, a Medicinally Valuable Flavonoid, in Escherichia coli

PubMed Central

Malla, Sailesh; Koffas, Mattheos A. G.; Kazlauskas, Romas J.

2012-01-01

7-O-Methyl aromadendrin (7-OMA) is an aglycone moiety of one of the important flavonoid-glycosides found in several plants, such as Populus alba and Eucalyptus maculata, with various medicinal applications. To produce such valuable natural flavonoids in large quantity, an Escherichia coli cell factory has been developed to employ various plant biosynthetic pathways. Here, we report the generation of 7-OMA from its precursor, p-coumaric acid, in E. coli for the first time. Primarily, naringenin (NRN) (flavanone) synthesis was achieved by feeding p-coumaric acid and reconstructing the plant biosynthetic pathway by introducing the following structural genes: 4-coumarate–coenzyme A (CoA) ligase from Petroselinum crispum, chalcone synthase from Petunia hybrida, and chalcone isomerase from Medicago sativa. In order to increase the availability of malonyl-CoA, a critical precursor of 7-OMA, genes for the acyl-CoA carboxylase α and β subunits (nfa9890 and nfa9940), biotin ligase (nfa9950), and acetyl-CoA synthetase (nfa3550) from Nocardia farcinica were also introduced. Thus, produced NRN was hydroxylated at position 3 by flavanone-3-hydroxylase from Arabidopsis thaliana, which was further methylated at position 7 to produce 7-OMA in the presence of 7-O-methyltransferase from Streptomyces avermitilis. Dihydrokaempferol (DHK) (aromadendrin) and sakuranetin (SKN) were produced as intermediate products. Overexpression of the genes for flavanone biosynthesis and modification pathways, along with malonyl-CoA overproduction in E. coli, produced 2.7 mg/liter (8.9 μM) 7-OMA upon supplementation with 500 μM p-coumaric acid in 24 h, whereas the strain expressing only the flavanone modification enzymes yielded 30 mg/liter (99.2 μM) 7-OMA from 500 μM NRN in 24 h. PMID:22101053

40 CFR 721.10188 - Fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Fatty acids, tall-oil, reaction... Fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine (generic). (a... generically as fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine (PMN...

40 CFR 721.10188 - Fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Fatty acids, tall-oil, reaction... Fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine (generic). (a... generically as fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine (PMN...

3-O-methyl sugars as constituents of glycoproteins. Identification of 3-O-methylgalactose and 3-O-methylmannose in pulmonate gastropod haemocyanins.

PubMed Central

Hall, R L; Wood, E J; Kamberling, J P; Gerwig, G J; Vliegenthart, F G

1977-01-01

In addition to the already knownonosaccharides fucose, xylose, mannose, galactose, glucose, N-acetylgalactosamine and N-acetylglucosamine, the carbohydrate part of the haemocyanin from Helix pomatia (Roman snail) contains 3-O-methylgalactose, and that from Lymnaea stagnalis (a freshwater snail) 3-O-methylgalactose and 3-O-methylmannose. The 3-O-methyl sugars were identified by g.l.c.-mas spectrometry of the corresponding trimethylsilyl methyl glycosides and the alditol acetates, and by co-chromatography with the synthetic reference substances. PMID:889564

A Molecular docking study to predict enantioseparation of some chiral carboxylic acid derivatives by methyl-β-cyclodextrin

NASA Astrophysics Data System (ADS)

Nurhidayah, E. S.; Ivansyah, A. L.; Martoprawiro, M. A.; Zulfikar, M. A.

2018-05-01

A molecular docking study, using molecular mechanics calculations with Arguslab, was used to help predict the enantioseparation of some guest molecules of chiral carboxylic acid derivatives by heptakis-2,6-di-O-methyl-β-cyclodextrin (DIMEB) and heptakis-2,3,6-tri-O-methyl-β-cyclodextrin (TRIMEB) as host molecules. The small differences in the binding free energy values (ΔΔG) obtained from Arguslab did not indicate any significant enantioseparation. From the molecular docking simulation results, it is predicted that in the case of DIMEB as host molecule, R-enantiomer of Etodolac, Fenoprofen, Indoprofen, Ketorolac, and Naproxen will be eluted first than S-enantiomer; However, S-enantiomer of Carprofen, Flurbiprofen, Ketoprofen, Pirprofen, Proglumide, Sulindac, Surprofen, and Zaltoprofen will be eluted first than R-enantiomer by DIMEB as host molecule. When TRIMEB is used as a host molecule, R-enantiomer of Carprofen, Flurbiprofen, Indoprofen, Ketoprofen, Naproxen, Pirprofen, and Surprofen will be eluted first than S-enantiomer; However, S-enantiomer of Etodolac, Fenoprofen, Ketorolac, Proglumide, Sulindac and Zaltoprofen will be eluted first than R-enantiomer by TRIMEB as host molecule.

DNA Methylation of Cellular Retinoic Acid-Binding Proteins in Cervical Cancer.

PubMed

Arellano-Ortiz, Ana L; Salcedo-Vargas, Mauricio; Vargas-Requena, Claudia L; López-Díaz, José A; De la Mora-Covarrubias, Antonio; Silva-Espinoza, Juan C; Jiménez-Vega, Florinda

2016-01-01

This study determined the methylation status of cellular retinoic acid-binding protein ( CRABP ) gene promoters and associated them with demographic characteristics, habits, and the presence of human papilloma virus (HPV) in patients with cervical cancer (CC), low and high squamous intraepithelial lesions, and no intraepithelial lesion. Women (n = 158) were selected from the Colposcopy Clinic of Sanitary Jurisdiction II in Ciudad Juarez, Chihuahua, Mexico. Demographic characteristics and habit information were collected. Cervical biopsy and endocervical scraping were used to determine methylation in promoter regions by methylation-specific polymerase chain reaction technique. We found hemi-methylation patterns in the promoter regions of CRABP1 and CRABP2 ; there was 28.5% hemi-methylation in CRABP1 and 7.0% in that of CRABP2 . Methylation in CRABP1 was associated with age (≥35 years, P = 0.002), family history of cancer ( P = 0.032), the presence of HPV-16 ( P = 0.013), and no alcohol intake ( P = 0.035). These epigenetic changes could be involved in the CC process, and CRABP1 has the potential to be a predictive molecular marker of retinoid therapy response.

DNA Methylation of Cellular Retinoic Acid-Binding Proteins in Cervical Cancer

PubMed Central

Arellano-Ortiz, Ana L.; Salcedo-Vargas, Mauricio; Vargas-Requena, Claudia L.; López-Díaz, José A.; De la Mora-Covarrubias, Antonio; Silva-Espinoza, Juan C.; Jiménez-Vega, Florinda

2016-01-01

This study determined the methylation status of cellular retinoic acid-binding protein (CRABP) gene promoters and associated them with demographic characteristics, habits, and the presence of human papilloma virus (HPV) in patients with cervical cancer (CC), low and high squamous intraepithelial lesions, and no intraepithelial lesion. Women (n = 158) were selected from the Colposcopy Clinic of Sanitary Jurisdiction II in Ciudad Juarez, Chihuahua, Mexico. Demographic characteristics and habit information were collected. Cervical biopsy and endocervical scraping were used to determine methylation in promoter regions by methylation-specific polymerase chain reaction technique. We found hemi-methylation patterns in the promoter regions of CRABP1 and CRABP2; there was 28.5% hemi-methylation in CRABP1 and 7.0% in that of CRABP2. Methylation in CRABP1 was associated with age (≥35 years, P = 0.002), family history of cancer (P = 0.032), the presence of HPV-16 (P = 0.013), and no alcohol intake (P = 0.035). These epigenetic changes could be involved in the CC process, and CRABP1 has the potential to be a predictive molecular marker of retinoid therapy response. PMID:27867303

DNA methylation perturbations in genes involved in polyunsaturated Fatty Acid biosynthesis associated with depression and suicide risk.

PubMed

Haghighi, Fatemeh; Galfalvy, Hanga; Chen, Sean; Huang, Yung-Yu; Cooper, Thomas B; Burke, Ainsley K; Oquendo, Maria A; Mann, J John; Sublette, M Elizabeth

2015-01-01

Polyunsaturated fatty acid (PUFA) status has been associated with neuropsychiatric disorders, including depression and risk of suicide. Long-chain PUFAs (LC-PUFAs) are obtained in the diet or produced by sequential desaturation and elongation of shorter-chain precursor fatty acids linoleic acid (LA, 18:2n-6) and α-linolenic acid (ALA, 18:3n-3). We compared DNA methylation patterns in genes involved in LC-PUFA biosynthesis in major depressive disorder (MDD) with (n = 22) and without (n = 39) history of suicide attempt, and age- and sex-matched healthy volunteers (n = 59). Plasma levels of selected PUFAs along the LC-PUFA biosynthesis pathway were determined by transesterification and gas chromatography. CpG methylation levels for the main human LC-PUFA biosynthetic genes, fatty acid desaturases 1 (Fads1) and 2 (Fads2), and elongation of very long-chain fatty acids protein 5 (Elovl5), were assayed by bisulfite pyrosequencing. Associations between PUFA levels and diagnosis or suicide attempt status did not survive correction for multiple testing. However, MDD diagnosis and suicide attempts were significantly associated with DNA methylation in Elovl5 gene regulatory regions. Also the relative roles of PUFA levels and DNA methylation with respect to diagnostic and suicide attempt status were determined by least absolute shrinkage and selection operator logistic regression analyses. We found that PUFA associations with suicide attempt status were explained by effects of Elovl5 DNA methylation within the regulatory regions. The observed link between plasma PUFA levels, DNA methylation, and suicide risk may have implications for modulation of disease-associated epigenetic marks by nutritional intervention.

beta-Methyl-15-p-iodophenylpentadecanoic acid metabolism and kinetics in the isolated rat heart.

PubMed

DeGrado, T R; Holden, J E; Ng, C K; Raffel, D M; Gatley, S J

1989-01-01

The use of 15-p-iodophenyl-beta-methyl-pentadecanoic acid (beta Me-IPPA) as an indicator of long chain fatty acid (LCFA) utilization in nuclear medicine studies was evaluated in the isolated, perfused, working rat heart. Time courses of radioactivity (residue curves) were obtained following bolus injections of both beta Me-IPPA and its straight chain counterpart 15-p-iodophenyl-pentadecanoic acid (IPPA). IPPA kinetics clearly indicated flow independent impairment of fatty acid oxidation caused by the carnitine palmitoyltransferase I inhibitor 2[5(4-chlorophenyl)pentyl]oxirane-2-carboxylate (POCA). In contrast, beta Me-IPPA kinetics were insensitive to changes in fatty acid oxidation rate and net utilization of long chain fatty acid. Analysis of radiolabeled species in coronary effluent and heart homogenates showed the methylated fatty acid to be readily incorporated into complex lipids but a poor substrate for oxidation. POCA did not significantly alter metabolism of the tracer, suggesting that the tracer is poorly metabolized beyond beta Me-IPPA-CoA in the oxidative pathway.

Fabrication of calcium phosphate–calcium sulfate injectable bone substitute using hydroxy-propyl-methyl-cellulose and citric acid

PubMed Central

Thai, Van Viet

2010-01-01

In this study, an injectable bone substitute (IBS) consisting of citric acid, chitosan, and hydroxyl propyl methyl cellulose (HPMC) as the liquid phase and tetra calcium phosphate (TTCP), dicalcium phosphate dihydrate (DCPD) and calcium sulfate dehydrate (CSD, CaSO4·2H2O) powders as the solid phase, were fabricated. Two groups were classified based on the percent of citric acid in the liquid phase (20, 40 wt%). In each groups, the HPMC percentage was 0, 2, and 4 wt%. An increase in compressive strength due to changes in morphology was confirmed by scanning electron microscopy images. A good conversion rate of HAp at 20% citric acid was observed in the XRD profiles. In addition, HPMC was not obviously affected by apatite formation. However, both HPMC and citric acid increased the compressive strength of IBS. The maximum compressive strength for IBS was with 40% citric acid and 4% HPMC after 14 days of incubation in 100% humidity at 37°C. PMID:20333539

Synthesis of carboxylic acids, esters, alcohols and ethers containing a tetrahydropyran ring derived from 6-methyl-5-hepten-2-one.

PubMed

Hanzawa, Yohko; Hashimoto, Kahoko; Kasashima, Yoshio; Takahashi, Yoshiko; Mino, Takashi; Sakamoto, Masami; Fujita, Tsutomu

2012-01-01

3-hydroxy acids, 3-hydroxy-3,7-dimethyloct-6-enoic acid (1) and 3-hydroxy-2,2,3,7-tetramethyloct-6-enoic acid (2), were prepared from 6-methyl-5-hepten-2-one, and they were subsequently used to prepare (2,6,6-trimethyltetrahydropyran-2-yl)acetic acid (3) and 2-methyl-2-(2,6,6-trimethyltetrahydropyran-2-yl)propanoic acid (4), respectively, via cyclization with an acidic catalyst such as boron trifluoride diethyl etherate or iodine. The reaction of carboxylic acids 3 and 4 with alcohols, including methanol, ethanol, and 1-propanol, produced the corresponding methyl, ethyl, and propyl esters, which all contained a tetrahydropyran ring. Reduction of carboxylic acids 3 and 4 afforded the corresponding alcohols. Subsequent reactions of these alcohols with several acyl chlorides produced novel esters. The alcohols also reacted with methyl iodide and sodium hydride to provide novel ethers. A one-pot cyclization-esterification of 1 to produce esters containing a tetrahydropyran ring, using iodine as a catalyst, was also investigated.

Experimental Study of Combustion and Emissions Characteristics of Methyl Oleate, as a Surrogate for Biodiesel, in a Direct injection Diesel Engine

USDA-ARS?s Scientific Manuscript database

This study evaluates the combustion and emissions characteristics of methyl oleate (C19H36O2 CAS# 112-62) produced by transesterification from oleic acid, one of the main fatty acid components of biodiesel. The ignition delay of ultra-low sulfur diesel#2 (ULSD) and its blends with methyl oleate (O20...

Structural elucidation of polysaccharide containing 3-O-methyl galactose from fruiting bodies of Pleurotus citrinopileatus.

PubMed

He, Pengfei; Zhang, Anqiang; Zhou, Saijing; Zhang, Fuming; Linhardt, Robert J; Sun, Peilong

2016-11-03

A water-soluble polysaccharide containing 3-O-methyl galactose (PCP60W) was isolated from fruiting bodies of Pleurotus citrinopileatus and purified by anion-exchange and gel column chromatography. This polysaccharide has an average molecular weight of 2.74 × 10 4  Da and its structure was elucidated using monosaccharide composition and methylation analysis combined with one- and two-dimensional (COSY, TOCSY, NOESY, HMQC and HMBC) NMR spectroscopy. PCP60W was shown to be a linear partially 3-O-methylated α-galactopyranan comprised of 6-linked galactose, 6-linked 3-O-methyl galactose and 4-linked glucose in a ratio of 3.0:1.0:0.6. This work provides additional evidence for the view that 3-O-methyl galactose is common to the genus Pleurotus. Copyright © 2016 Elsevier Ltd. All rights reserved.

Methyl Jasmonate and Salicylic Acid Enhanced the Production of Ursolic and Oleanolic Acid in Callus Cultures of Lepechinia Caulescens

PubMed Central

Vergara Martínez, Víctor M.; Estrada-Soto, Samuel E.; Arellano-García, José de Jesús; Rivera-Leyva, Julio C.; Castillo-España, Patricia; Flores, Angélica Flores; Cardoso-Taketa, Alexandre T.; Perea-Arango, Irene

2017-01-01

Background: The production of triterpenes from plants for pharmacological purposes varies in concentration, due to genetic and environmental factors. In vitro culture enables the control and increase of these bioactive molecules. Objective: To evaluate the effect of plant growth regulators and elicitors in the induction of calli and the production of ursolic acid (UA) and oleanolic acid (OA) in Lepechinia caulescens. Materials and Methods: Leaf explants were exposed for the induction of calli at different concentrations and combinations of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzylaminopurine (BAP). Methyl jasmonate (MJ) and salicylic acid were used as elicitors. High-performance liquid chromatography method was used to quantify UA and OA content in each treatment. Results: Treatment with 3.0 mg/L of 2,4-D and 0.1 mg/L of BAP produced the best results for calli induction and production of UA (1.57 mg/g dry weight [DW]) and OA (1.13 mg/g DW). Both elicitors facilitated the accumulation of triterpenes. Conclusion: The combination of auxins and cytokinins showed favorable results for the induction of calli. Variation concerning the accumulation of UA and OA was observed between treatments. MJ increased the production of triterpenes five times after 8 h of exposure, compared to control treatment. There is a greater accumulation of UA (16.58 mg/g DW) and OA (1.94 mg/g DW) in leaves of wild plants. SUMMARY Callus cultures of Lepechinia caulescens were obtained from leaf explants treated with 2,4-dichlorophenoxyacetic acid and 6-bencylaminopurineResulting cultures were elicited with methyl jasmonate (MJ) and salicylic acid to increase the production of the triterpenes, ursolic acid (UA), and oleanolic acid (OA)The cultures elicited with MJ increased the production of UA and OA five times, as compared to the control. Abbreviations used: 2,4-D: 2,4-dichlorophenoxyacetic acid, BAP: 6-benzylaminopurine, DW: Dry weight, MJ: Methyl jasmonate, OA: Oleanolic acid, PGRs

Chemical carcinogenesis in the nervous system. Preferential accumulation of O6-methylguanine in rat brain deoxyribonucleic acid during repetitive administration of N-methyl-N-nitrosourea.

PubMed Central

Margison, G P; Kleihues, P

1975-01-01

The alkylation of purine bases in DNA of several rat tissues was determined during weekly injections (10 mg/kg) of N-[3H]methyl-N-nitrosourea, a dose schedule known to selectively induce tumours of the nervous system. Each group of animals was killed 1 week after the final injection, and the DNA hydrolysates were analysed by chromatography on Sephadex G-10. After five weekly applications, O6-methylguanine had accumulated in brain DNA to an extent which greatly exceeded that in kidney, spleen and intestine. In the liver, the final O6-methylguanine concentration was less than 1% of that in brain. Between the first and the fifth injection, the O6-methylguanine/7-methylguanine ratio in cerebral DNA increased from 0.28 to 0.68. In addition, 3-methylguanine was found to accumulate in brain DNA whereas in the other organs no significant quantities of this base were detectable. The results are compatible with the hypothesis that O6-alkylation of guanine in DNA plays a major role in the induction of tumours by N-methyl-N-nitrosourea and related carcinogens. The kinetics of the increase of O6-methylguanine in cerebral DNA suggest that there is no major cell fraction in the brain which is capable of excising chemically methylated bases from DNA. This repair deficiency could be a determining factor in the selective induction of nervous-system tumours by N-methyl-N-nitrosourea and other neuro-oncogenic compounds. PMID:1200992

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

Code of Federal Regulations, 2013 CFR

2013-04-01

... from edible fats and oils. 172.225 Section 172.225 Food and Drugs FOOD AND DRUG ADMINISTRATION... Methyl and ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in food, subject to the...

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

Code of Federal Regulations, 2012 CFR

2012-04-01

... from edible fats and oils. 172.225 Section 172.225 Food and Drugs FOOD AND DRUG ADMINISTRATION... Methyl and ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in food, subject to the...

Alternative fuel properties of tall oil fatty acid methyl ester-diesel fuel blends.

PubMed

Altiparmak, Duran; Keskin, Ali; Koca, Atilla; Gürü, Metin

2007-01-01

In this experimental work, tall oil methyl ester-diesel fuel blends as alternative fuels for diesel engines were studied. Tall oil methyl ester was produced by reacting tall oil fatty acids with methyl alcohol under optimum conditions. The blends of tall oil methyl ester-diesel fuel were tested in a direct injection diesel engine at full load condition. The effects of the new fuel blends on the engine performance and exhaust emission were tested. It was observed that the engine torque and power output with tall oil methyl ester-diesel fuel blends increased up to 6.1% and 5.9%, respectively. It was also seen that CO emissions decreased to 38.9% and NO(x) emissions increased up to 30% with the new fuel blends. The smoke opacity did not vary significantly.

Structural basis for m7G recognition and 2'-O-methyl discrimination in capped RNAs by the innate immune receptor RIG-I

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

Devarkar, Swapnil C.; Wang, Chen; Miller, Matthew T.

The cytosolic innate immune receptor Retinoic Acid Inducible Gene-I (RIG-I) is the principal detector of pathogenic RNAs carrying a 5'-triphosphate (5'ppp). Self RNAs like mRNAs evade recognition by RIG-I due to posttranscriptional modifications like 5'-end capping with 7-methyl guanosine (m7G) and 2'-O-methylation of 5'-end nucleotides. Viruses have also evolved mechanisms to mimic these modifications, which in part is believed to aid in immune evasion. Currently, it is unclear how these modifications modulate RIG-I recognition. This paper provides structural and mechanistic insights into the roles of the m7G cap and 2'-O-methylation in RIG-I evasion. We show that RIG-I accommodates the m7Gmore » base while maintaining the 5'ppp contacts and can recognize Cap-0 RNAs but not Cap-1.« less

Detection and quantification of RNA 2′-O-methylation and pseudouridylation

PubMed Central

Karijolich, John

2016-01-01

RNA-guided RNA modification is a naturally occurring process that introduces 2′-O-methylation and pseudouridylation into rRNA, spliceosomal snRNA and several other types of RNA. The Box C/D ribonucleoproteins (RNP) and Box H/ACA RNP, each containing one unique guide RNA (Box C/D RNA or Box H/ACA RNA) and a set of core proteins, are responsible for 2′-O-methylation and pseudouridylation respectively. Box C/D RNA and Box H/ACA RNA provide the modification specificity through base pairing with their RNA substrate. These post-transcriptional modifications could profoundly alter the properties and functions of substrate RNAs. Thus it is desirable to establish reliable and standardized modification methods to study biological functions of modified nucleotides in RNAs. Here, we present several sensitive and efficient methods and protocols for detecting and quantifying post-transcriptional 2′-O-methylation and pseudouridylation. PMID:26853326

No effect of folic acid supplementation on global DNA methylation in men and women with moderately elevated homocysteine.

PubMed

Jung, Audrey Y; Smulders, Yvo; Verhoef, Petra; Kok, Frans J; Blom, Henk; Kok, Robert M; Kampman, Ellen; Durga, Jane

2011-01-01

A global loss of cytosine methylation in DNA has been implicated in a wide range of diseases. There is growing evidence that modifications in DNA methylation can be brought about by altering the intake of methyl donors such as folate. We examined whether long-term daily supplementation with 0.8 mg of folic acid would increase global DNA methylation compared with placebo in individuals with elevated plasma homocysteine. We also investigated if these effects were modified by MTHFR C677T genotype. Two hundred sixteen participants out of 818 subjects who had participated in a randomized double-blind placebo-controlled trial were selected, pre-stratified on MTHFR C677T genotype and matched on age and smoking status. They were allocated to receive either folic acid (0.8 mg/d; n = 105) or placebo treatment (n = 111) for three years. Peripheral blood leukocyte DNA methylation and serum and erythrocyte folate were assessed. Global DNA methylation was measured using liquid chromatography-tandem mass spectrometry and expressed as a percentage of 5-methylcytosines versus the total number of cytosine. There was no difference in global DNA methylation between those randomized to folic acid and those in the placebo group (difference = 0.008, 95%CI = -0.05,0.07, P = 0.79). There was also no difference between treatment groups when we stratified for MTHFR C677T genotype (CC, n = 76; CT, n = 70; TT, n = 70), baseline erythrocyte folate status or baseline DNA methylation levels. In moderately hyperhomocysteinemic men and women, long-term folic acid supplementation does not increase global DNA methylation in peripheral blood leukocytes.ClinicalTrials.gov NCT00110604.

Determination of the structure and catalytic mechanism of Sorghum bicolor caffeic acid O-methyltransferase and the structural impact of three brown midrib12 mutations

USDA-ARS?s Scientific Manuscript database

With S-adenosylmethionine (SAM) acting as the methyl donor, caffeic acid O-methyltransferase from Sorghum bicolor (SbCOMT) methylates the 5-hydroxyl group of its preferred substrate, 5-hydroxyconiferaldehyde, to form sinapaldehyde. In order to determine the mechanism of SbCOMT and understand the red...

Periconceptional Folic Acid Supplementation Benefit to Development of Early Sensory-Motor Function through Increase DNA Methylation in Rat Offspring

PubMed Central

Li, Wen; Li, Zhenshu; Li, Shou; Wang, Xinyan; Wilson, John X.; Huang, Guowei

2018-01-01

Periconceptional maternal folate levels may alter DNA methylation patterns and health outcomes in offspring. We hypothesized that maternal folic acid supplementation alters fetal neural development through DNA methylation in the fetal brain. Twenty-eight rats were randomly assigned to four groups: three groups of the female rats were fed folate-normal, folate-deficient or folate-supplemented diets from seven days before mating to delivery. In another group, folic acid supplementation diet short-period group was fed a folate-normal diet, except for 10 days (begin mating) when this group was fed a folate-supplemented diet. After delivery, the diets were changed to folate-normal diet for all four groups. The cliff avoidance and forelimb grip tests were used to assess sensory motor function of rat offspring. The results indicate that maternal folic acid supplementation improved the early development of sensory-motor function in offspring. Maternal folic acid supplementation increased the methylation potential, global DNA methylation (5-mC) and DNA methyltransferase expression and activity in the brains of the offspring. In conclusion, maternal folic acid supplementation increases DNA methylation pattern in offspring brain and improves the early development of sensory-motor function. PMID:29494536

Fourier transformation microwave spectroscopy of the methyl glycolate-H2O complex

NASA Astrophysics Data System (ADS)

Fujitake, Masaharu; Tanaka, Toshihiro; Ohashi, Nobukimi

2018-01-01

The rotational spectrum of one conformer of the methyl glycolate-H2O complex has been measured by means of the pulsed jet Fourier transform microwave spectrometer. The observed a- and b-type transitions exhibit doublet splittings due to the internal rotation of the methyl group. On the other hand, most of the c-type transitions exhibit quartet splittings arising from the methyl internal rotation and the inversion motion between two equivalent conformations. The spectrum was analyzed using parameterized expressions of the Hamiltonian matrix elements derived by applying the tunneling matrix formalism. Based on the results obtained from ab initio calculation, the observed complex of methyl glycolate-H2O was assigned to the most stable conformer of the insertion complex, in which a non-planer seven membered-ring structure is formed by the intermolecular hydrogen bonds between methyl glycolate and H2O subunits. The inversion motion observed in the c-type transitions is therefore a kind of ring-inversion motion between two equivalent conformations. Conformational flexibility, which corresponds to the ring-inversion between two equivalent conformations and to the isomerization between two possible conformers of the insertion complex, was investigated with the help of the ab initio calculation.

On the cleavage of the peroxide O---O bond in methyl hydroperoxide and dimethyl peroxide upon protonation

NASA Astrophysics Data System (ADS)

Schalley, Christoph A.; Dieterle, Martin; Schröder, Detlef; Schwarz, Helmut; Uggerud, Einar

1997-04-01

The unimolecular decays of protonated methyl hydroperoxide and dimethyl peroxide have been studied by tandem mass spectrometric techniques in combination with isotopic labeling as well as computational methods. The potential-energy surfaces calculated at the BECKE3LYP/6-311++G** level of theory are in good agreement with the experimental findings. The decomposition of the protonated peroxides can be described by a general mechanistic scheme which involves rearrangement to proton-bridged complexes, i.e. [CH2O-H-OH2]+ and [CH2O-H-O(H)CH3]+, respectively. When formed unimolecularly via rearrangement of the protonated peroxides, these complexes are rovibrationally highly excited; consequently, their fragmentations are affected remarkably as compared to proton-bound complexes of lower internal energy which are independently generated from the corresponding alcohol and carbonyl compounds in a chemical ionization plasma. For methyl hydroperoxide, both oxygen atoms can be protonated, giving rise to two isomeric cations with rather similar heats of formation but entirely different fragmentation behaviors. Cleavage of the O---O bond in dimethyl peroxide upon protonation results in proton- as well as methyl-cation-bridged intermediates, e.g. [CH2O-H-O(H)CH3]+ and [CH2O-CH3-OH2]+.

Acylamino acid chiral fungicides on toxiciepigenetics in lambda DNA methylation.

PubMed

Yin, Jing; Zhu, Feilong; Hao, Weiyu; Xu, Qi; Chang, Jin; Wang, Huili; Guo, Baoyuan

2017-11-01

Acylamino acid chiral fungicides (AACFs) are low-toxicity pesticides and considered as non-carcinogenic chemicals to laboratory animals. Though AACFs have potential toxicological effects on mammals by non-genotoxic mechanisms, the toxicoepigenomics of AACFs has not been documented. In this article, we explored toxiciepigenetics of metalaxyl, benalaxyl and furalaxyl through epigenetics research on lambda DNA under different concentration exposure. The toxicoepigenomic difference of stereoisomers was examined also. Our results showed that AACFs would affect methyltransferase activity resulting in modulating DNA methylation levels and pattern. The LOAEL of R-metalaxyl and S-metalaxyl were 30 mM and 0.3 mM, respectively. The LOAEL of (R, S)-benalaxyl and (R, S)-furalaxyl were 0.3 Mm and 30 mM, respectively. A significant dose-response effect between (R, S)-benalaxyl and global methylation level was observed. Global methylation level was more susceptible to S-enantiomer compared to R-enantiomer, which indicated enantiomers of AACFs have the enantioselectivity in toxiciepigenetics. Moreover, the dependence of the methylation inhibition on the chiral center of metalaxyl may suggest a considerable specificity of the compound of AACFs for DNA methyltransferases. The inhibition effect between R-enantiomer and S-enantiomer of AACFs on DNA methylation levels generated in this study is important for low-toxicity pesticides toxicoepigenomics evaluation. Copyright © 2017 Elsevier Ltd. All rights reserved.

A microfluidic device for the automated derivatization of free fatty acids to fatty acid methyl esters.

PubMed

Duong, Cindy T; Roper, Michael G

2012-02-21

Free fatty acid (FFA) compositions are examined in feedstock for biodiesel production, as source-specific markers in soil, and because of their role in cellular signaling. However, sample preparation of FFAs for gas chromatography-mass spectrometry (GC-MS) analysis can be time and labor intensive. Therefore, to increase sample preparation throughput, a glass microfluidic device was developed to automate derivatization of FFAs to fatty acid methyl esters (FAMEs). FFAs were delivered to one input of the device and methanolic-HCl was delivered to a second input. FAME products were produced as the reagents traversed a 29 μL reaction channel held at 55 °C. A Design of Experiment protocol was used to determine the combination of derivatization time (T(der)) and ratio of methanolic-HCl:FFA (R(der)) that maximized the derivatization efficiencies of tridecanoic acid and stearic acid to their methyl ester forms. The combination of T(der) = 0.8 min and R(der) = 4.9 that produced optimal derivatization conditions for both FFAs within a 5 min total sample preparation time was determined. This combination of T(der) and R(der) was used to derivatize 12 FFAs with a range of derivatization efficiencies from 18% to 93% with efficiencies of 61% for tridecanoic acid and 84% for stearic acid. As compared to a conventional macroscale derivatization of FFA to FAME, the microfluidic device decreased the volume of methanolic-HCl and FFA by 20- and 1300-fold, respectively. The developed microfluidic device can be used for automated preparation of FAMEs to analyze the FFA compositions of volume-limited samples.

Deoxygenation of methyl laurate over Ni based catalysts: Influence of supports

NASA Astrophysics Data System (ADS)

Xia, Xiaoqiang; Chen, Hui; Bi, Yadong; Hu, Jianli

2017-10-01

The use of a series of nickel based catalysts supported over HZSM-5, Al2O3, C and ZrO2 in the deoxygenation of methyl laurate shows that the deoxygenation activity and deoxygenation pathway of nickel based catalysts can be affected by properties of catalysts. In the absence of H2, β-elimination of methyl laurate is the dominant reaction and a small amount of laurate acid is converted into undecane by direct decarboxylation. At the same time, the highly acidic support HZSM-5 gave higher conversion and C11 alkane selectivity. In the presence of H2, Ni/HZSM-5 catalyst showed a significantly high deoxygenation activity, producing 71% alkanes by methyl laurate conversion at 280 °C and 4MPa H2. While as on mildly acidic (Al2O3) and neutral (C) supports, a restricted hydrodeoxygenation activity was achieved but more oxygenate products were yielded. According to the analysis of intermediate product, the deoxygenation reaction of methyl laurate follows three distinct pathways: in the absence of H2, decarboxylation: C11H23COOCH3→C11H23COOH→C11H24; in the presence of H2, decarbonylation: C11H23COOCH3→C11H23COOH→C11H23CHO→C11H24; and hydrodeoxygenation: C11H23COOCH3 →C11H23COOH→C11H23CHO→C12H25OH→C12H26

Cold flow properties of fatty acid methyl esters: Additives versus diluents

USDA-ARS?s Scientific Manuscript database

Biodiesel is typically composed of fatty acid methyl esters (FAME) converted from agricultural lipids. Common feedstocks include soybean oil, canola oil, rapeseed oil, sunflower oil, and palm oil. Recent debate on the conversion of edible oils into non-food products has created opportunities to deve...

Protonated sugars: vibrational spectroscopy and conformational structure of protonated O-methyl α-D-galactopyranoside

NASA Astrophysics Data System (ADS)

Rudić, Svemir; Xie, Hong-bin; Gerber, R. Benny; Simons, John P.

2012-08-01

'Bridging' protons provide a common structural motif in biological assemblies such as proton wires and proton-bound dimers. Here we present a 'proof-of-principle' computational and vibrational spectroscopic investigation of an 'intra-molecular proton-bound dimer,' O-methyl α-D-galactopyranoside (αMeGal-H+), generated in the gas phase through photo-ionisation of its complex with phenol in a molecular beam. Its vibrational spectrum corresponds well with a classical molecular dynamics simulation conducted 'on-the-fly' and also with the lowest-energy structures predicted by DFT and ab initio calculations. They reveal proton-bound structures that bridge neighbouring pairs of oxygen atoms, preferentially O6 and O4, linked together within the carbohydrate scaffold. Motivated by the possibility of an entry into the microscopic mechanism of its acid (or enzyme)-catalysed hydrolysis, we also report the corresponding predictions for its singly hydrated complex.

Low-temperature phase behavior of fatty acid methyl esters by differential scanning calorimetry (DSC)

USDA-ARS?s Scientific Manuscript database

Fatty acid methyl ester (FAME) mixtures have many uses including biodiesel, lubricants, metal-working fluids, surfactants, polymers, coatings, green solvents and phase-change materials. The physical properties of a FAME mixture depends on the fatty acid concentration (FAC) profile. Some products hav...

Genomic DNA Methylation Changes in Response to Folic Acid Supplementation in a Population-Based Intervention Study among Women of Reproductive Age

PubMed Central

Berry, Robert J.; Hao, Ling; Li, Zhu; Maneval, David; Yang, Thomas P.; Rasmussen, Sonja A.; Yang, Quanhe; Zhu, Jiang-Hui; Hu, Dale J.; Bailey, Lynn B.

2011-01-01

Folate is a source of one-carbons necessary for DNA methylation, a critical epigenetic modification necessary for genomic structure and function. The use of supplemental folic acid is widespread however; the potential influence on DNA methylation is unclear. We measured global DNA methylation using DNA extracted from samples from a population-based, double-blind randomized trial of folic acid supplementation (100, 400, 4000 µg per day) taken for 6 months; including a 3 month post-supplementation sample. We observed no changes in global DNA methylation in response to up to 4,000 µg/day for 6 months supplementation in DNA extracted from uncoagulated blood (approximates circulating blood). However, when DNA methylation was determined in coagulated samples from the same individuals at the same time, significant time, dose, and MTHFR genotype-dependent changes were observed. The baseline level of DNA methylation was the same for uncoagulated and coagulated samples; marked differences between sample types were observed only after intervention. In DNA from coagulated blood, DNA methylation decreased (−14%; P<0.001) after 1 month of supplementation and 3 months after supplement withdrawal, methylation decreased an additional 23% (P<0.001) with significant variation among individuals (max+17%; min-94%). Decreases in methylation of ≥25% (vs. <25%) after discontinuation of supplementation were strongly associated with genotype: MTHFR CC vs. TT (adjusted odds ratio [aOR] 12.9, 95%CI 6.4, 26.0). The unexpected difference in DNA methylation between DNA extracted from coagulated and uncoagulated samples in response to folic acid supplementation is an important finding for evaluating use of folic acid and investigating the potential effects of folic acid supplementation on coagulation. PMID:22163281

Experimental and numerical investigations on spray characteristics of fatty acid methyl esters

NASA Astrophysics Data System (ADS)

Lanjekar, R. D.; Deshmukh, D.

2018-02-01

A comparative experimental and numerical study is conducted to establish the significance of the use of single-component over multi-component representatives of biodiesel, diesel and their blend for predicting spray tip penetration. Methyl oleate and methyl laurate are used as single-component representative fuels for biodiesel. The pure components n-heptane, n-dodecane and n-tetradecane are used as single-component representative fuels for diesel. Methyl laurate is found to represent biodiesel of coconut, whereas methyl oleate is found to represent biodiesel having high percentage of long-chain fatty acid esters. The spray tip penetration of methyl oleate is found to be in good agreement with the measured spray tip penetration of karanja biodiesel. The spray tip penetration prediction of n-heptane fuel is closely following diesel spray tip penetration along with that of n-tetradecane and n-dodecane. The study suggests that the knowledge of the single-component representatives of biodiesel, diesel and their blend is sufficient to predict the spray tip penetration of the corresponding biodiesel, diesel and their blend under non-evaporating environment.

Experimental and numerical investigations on spray characteristics of fatty acid methyl esters.

PubMed

Lanjekar, R D; Deshmukh, D

2018-02-01

A comparative experimental and numerical study is conducted to establish the significance of the use of single-component over multi-component representatives of biodiesel, diesel and their blend for predicting spray tip penetration. Methyl oleate and methyl laurate are used as single-component representative fuels for biodiesel. The pure components n -heptane, n -dodecane and n -tetradecane are used as single-component representative fuels for diesel. Methyl laurate is found to represent biodiesel of coconut, whereas methyl oleate is found to represent biodiesel having high percentage of long-chain fatty acid esters. The spray tip penetration of methyl oleate is found to be in good agreement with the measured spray tip penetration of karanja biodiesel. The spray tip penetration prediction of n -heptane fuel is closely following diesel spray tip penetration along with that of n -tetradecane and n -dodecane. The study suggests that the knowledge of the single-component representatives of biodiesel, diesel and their blend is sufficient to predict the spray tip penetration of the corresponding biodiesel, diesel and their blend under non-evaporating environment.

Experimental and numerical investigations on spray characteristics of fatty acid methyl esters

PubMed Central

Deshmukh, D.

2018-01-01

A comparative experimental and numerical study is conducted to establish the significance of the use of single-component over multi-component representatives of biodiesel, diesel and their blend for predicting spray tip penetration. Methyl oleate and methyl laurate are used as single-component representative fuels for biodiesel. The pure components n-heptane, n-dodecane and n-tetradecane are used as single-component representative fuels for diesel. Methyl laurate is found to represent biodiesel of coconut, whereas methyl oleate is found to represent biodiesel having high percentage of long-chain fatty acid esters. The spray tip penetration of methyl oleate is found to be in good agreement with the measured spray tip penetration of karanja biodiesel. The spray tip penetration prediction of n-heptane fuel is closely following diesel spray tip penetration along with that of n-tetradecane and n-dodecane. The study suggests that the knowledge of the single-component representatives of biodiesel, diesel and their blend is sufficient to predict the spray tip penetration of the corresponding biodiesel, diesel and their blend under non-evaporating environment. PMID:29515835

Acid base chemistry of luteolin and its methyl-ether derivatives: A DFT and ab initio investigation

NASA Astrophysics Data System (ADS)

Amat, Anna; De Angelis, Filippo; Sgamellotti, Antonio; Fantacci, Simona

2008-09-01

The acid-base chemistry of luteolin, a flavonoid with important pharmacological and dyeing properties, and of the related methyl ether derivatives have been investigated by DFT and MP2 methods, testing different computational setups. We calculate the pK's of all the possible deprotonation sites, for which no experimental assignment could be achieved. The calculated pK's deliver a different acidity order for the two most acidic deprotonation sites between luteolin and its methyl ether derivatives, due to intramolecular hydrogen bonding in luteolin. A lowest p Ka of 6.19 is computed for luteolin, in good agreement with available experimental data.

Structure--activity studies for alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropanoic acid receptors: acidic hydroxyphenylalanines.

PubMed

Hill, R A; Wallace, L J; Miller, D D; Weinstein, D M; Shams, G; Tai, H; Layer, R T; Willins, D; Uretsky, N J; Danthi, S N

1997-09-26

Antagonists of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropanoic acid (AMPA) receptors may have therapeutic potential as psychotropic agents. A series of mononitro- and dinitro-2- and 3-hydroxyphenylalanines was prepared, and their activity compared with willardiine, 5-nitrowillardiine, AMPA, and 2,4,5-trihydroxyphenylalanine (6-hydroxydopa) as inhibitors of specific [3H]AMPA and [3H]kainate binding in rat brain homogenates. The most active compounds were highly acidic (pKa 3-4), namely, 2-hydroxy-3,5-dinitro-DL-phenylalanine (13; [3H]AMPA IC50 approximately equal to 25 microM) and 3-hydroxy-2,4-dinitro-DL-phenylalanine (19; [3H]AMPA IC50 approximately equal to 5 microM). Two other dinitro-3-hydroxyphenylalanines, and 3,5-dinitro-DL-tyrosine, were considerably less active. Various mononitrohydroxyphenylalanines, which are less acidic, were also less active or inactive, and 2- and 3-hydroxyphenylalanine (o- and m-tyrosine) were inactive. Compounds 13 and 19, DL-willardiine (pKa 9.3, [3H]AMPA IC50 = 2 microM), and 5-nitro-DL-willardiine (pKa 6.4, [3H]AMPA IC50 = 0.2 microM) displayed AMPA > kainate selectivity in binding studies. Compound 19 was an AMPA-like agonist, but 13 was an antagonist in an AMPA-evoked norepinephrine release assay in rat hippocampal nerve endings. Also, compound 13 injected into the rat ventral pallidum antagonized the locomotor activity elicited by systemic amphetamine.

40 CFR 180.483 - O-[2-(1,1-Dimethylethyl)-5-pyrimidinyl] O-ethyl-O-(1-methyl-ethyl) phosphorothioate; tolerances...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false O-[2-(1,1-Dimethylethyl)-5-pyrimidinyl] O-ethyl-O-(1-methyl-ethyl) phosphorothioate; tolerances for residues. 180.483 Section 180.483... EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.483 O-[2-(1,1-Dimethylethyl)-5...

40 CFR 721.10450 - Oxirane, 2-[[3-(trimethoxysilyl)propoxy]methyl]-, reaction products with wollastonite (Ca(SiO3)).

Code of Federal Regulations, 2014 CFR

2014-07-01

... Oxirane, 2-[[3-(trimethoxysilyl)propoxy]methyl]-, reaction products with wollastonite (Ca(SiO3)). (a...)propoxy]methyl]-, reaction products with wollastonite (Ca(SiO3)). 721.10450 Section 721.10450 Protection... oxirane, 2-[[3-(trimethoxysilyl)propoxy]methyl]-, reaction products with wollastonite (Ca(SiO3)) (PMN P-02...

40 CFR 721.10450 - Oxirane, 2-[[3-(trimethoxysilyl)propoxy]methyl]-, reaction products with wollastonite (Ca(SiO3)).

Code of Federal Regulations, 2013 CFR

2013-07-01

... Oxirane, 2-[[3-(trimethoxysilyl)propoxy]methyl]-, reaction products with wollastonite (Ca(SiO3)). (a...)propoxy]methyl]-, reaction products with wollastonite (Ca(SiO3)). 721.10450 Section 721.10450 Protection... oxirane, 2-[[3-(trimethoxysilyl)propoxy]methyl]-, reaction products with wollastonite (Ca(SiO3)) (PMN P-02...

Synthesis of fatty acid methyl ester from the transesterification of high- and low-acid-content crude palm oil (Elaeis guineensis) and karanj oil (Pongamia pinnata) over a calcium-lanthanum-aluminum mixed-oxides catalyst.

PubMed

Syamsuddin, Y; Murat, M N; Hameed, B H

2016-08-01

The synthesis of fatty acid methyl ester (FAME) from the high- and low-acid-content feedstock of crude palm oil (CPO) and karanj oil (KO) was conducted over CaO-La2O3-Al2O3 mixed-oxide catalyst. Various reaction parameters were investigated using a batch reactor to identify the best reaction condition that results in the highest FAME yield for each type of oil. The transesterification of CPO resulted in a 97.81% FAME yield with the process conditions of 170°C reaction temperature, 15:1 DMC-to-CPO molar ratio, 180min reaction time, and 10wt.% catalyst loading. The transesterification of KO resulted in a 96.77% FAME yield with the conditions of 150°C reaction temperature, 9:1 DMC-to-KO molar ratio, 180min reaction time, and 5wt.% catalyst loading. The properties of both products met the ASTM D6751 and EN 14214 standard requirements. The above results showed that the CaO-La2O3-Al2O3 mixed-oxide catalyst was suitable for high- and low-acid-content vegetable oil. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chemical modification of nanocellulose with canola oil fatty acid methyl ester

Treesearch

Liqing Wei; Umesh P. Agarwal; Kolby C. Hirth; Laurent M. Matuana; Ronald C. Sabo; Nicole M. Stark

2017-01-01

Cellulose nanocrystals (CNCs), produced from dissolving wood pulp, were chemically functionalized by transesterification with canola oil fatty acid methyl ester (CME). CME performs as both the reaction reagent and solvent. Transesterified CNC (CNCFE) was characterized for their chemical structure, morphology, crystalline structure, thermal stability, and hydrophobicity...

Functional characterization of O-methyltransferases used to catalyse site-specific methylation in the post-tailoring steps of pradimicin biosynthesis.

PubMed

Han, J W; Ng, B G; Sohng, J K; Yoon, Y J; Choi, G J; Kim, B S

2018-01-01

To identify the roles of the two O-methyltransferase homologous genes pdmF and pdmT in the pradimicin biosynthetic gene cluster of Actinomadura hibisca P157-2. Pradimicins are pentangular polyphenol antibiotics synthesized by bacterial type II polyketide synthases (PKSs) and tailoring enzymes. Pradimicins are naturally derivatized by combinatorial O-methylation at two positions (i.e., 7-OH and 11-OH) of the benzo[α]naphthacenequinone structure. PdmF and PdmT null mutants (PFKO and PTKO) were generated. PFKO produced the 11-O-demethyl shunt metabolites 11-O-demethylpradimicinone II (1), 11-O-demethyl-7-methoxypradimicinone II (2), 11-O-demethylpradimicinone I (3) and 11-O-demethylpradimicin A (4), while PTKO generated the 7-O-demethyl derivatives pradimicinone II (5) and 7-hydroxypradimicin A (6). Pradimicinones 1, 2, 3, and 5 were fed to a heterologous host Escherichia coli harbouring expression plasmid pET-22b::pdmF or pET-28a::pdmT. PdmF catalysed 11-O-methylation of pradimicinones 1, 2, and 3 regardless of O-methylation at the C-7 position, while PdmT was unable to catalyse 7-O-methylation when the C-11 hydroxyl group was methylated (5). PdmF and PdmT were involved in 11-O- and 7-O-methylations of the benzo[α]naphthacenequinone moiety of pradimicin, respectively. Methylation of the C-7 hydroxyl group precedes methylation of the C-11 hydroxyl group in pradimicin biosynthesis. This is the first reported demonstration of the functions of PdmF and PdmT for regiospecific O-methylation, which contributes to better understanding of the post-PKS modifications in pradimicin biosynthesis as well as to rational engineering of the pradimicin biosynthetic machinery. © 2017 The Society for Applied Microbiology.

Unraveling Additional O-Methylation Steps in Benzylisoquinoline Alkaloid Biosynthesis in California Poppy (Eschscholzia californica).

PubMed

Purwanto, Ratmoyo; Hori, Kentaro; Yamada, Yasuyuki; Sato, Fumihiko

2017-09-01

California poppy (Eschscholzia californica), a member of the Papaveraceae family, produces many biologically active benzylisoquinoline alkaloids (BIAs), such as sanguinarine, macarpine and chelerythrine. Sanguinarine biosynthesis has been elucidated at the molecular level, and its biosynthetic genes have been isolated and used in synthetic biology approaches to produce BIAs in vitro. However, several genes involved in the biosynthesis of macarpine and chelerythrine have not yet been characterized. In this study, we report the isolation and characterization of a novel O-methyltransferase (OMT) involved in the biosynthesis of partially characterized BIAs, especially chelerythrine. A search of the RNA sequence database from NCBI and PhytoMetaSyn for the conserved OMT domain identified 68 new OMT-like sequences, of which the longest 22 sequences were selected based on sequence similarity. Based on their expression in cell lines with different macarpine/chelerythrine profiles, we selected three OMTs (G2, G3 and G11) for further characterization. G3 expression in Escherichia coli indicated O-methylation activity of the simple benzylisoquinolines, including reticuline and norreticuline, and the protoberberine scoulerine with dual regio-reactivities. G3 produced 7-O-methylated, 3'-O-methylated and dual O-methylated products from reticuline and norreticuline, and 9-O-methylated tetrahydrocolumbamine, 2-O-methylscoulerine and tetrahydropalmatine from scoulerine. Further enzymatic analyses suggested that G3 is a scoulerine-9-O-methyltransferase for the biosynthesis of chelerythrine in California poppy. In the present study, we discuss the physiological role of G3 in BIA biosynthesis. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Genetic and epigenetic transgenerational implications related to omega-3 fatty acids. Part I: maternal FADS2 genotype and DNA methylation correlate with polyunsaturated fatty acid status in toddlers: an exploratory analysis.

PubMed

Lupu, Daniel S; Cheatham, Carol L; Corbin, Karen D; Niculescu, Mihai D

2015-11-01

Polyunsaturated fatty acid metabolism in toddlers is regulated by a complex network of interacting factors. The contribution of maternal genetic and epigenetic makeup to this milieu is not well understood. In a cohort of mothers and toddlers 16 months of age (n = 65 mother-child pairs), we investigated the association between maternal genetic and epigenetic fatty acid desaturase 2 (FADS2) profiles and toddlers' n-6 and n-3 fatty acid metabolism. FADS2 rs174575 variation and DNA methylation status were interrogated in mothers and toddlers, as well as food intake and plasma fatty acid concentrations in toddlers. A multivariate fit model indicated that maternal rs174575 genotype, combined with DNA methylation, can predict α-linolenic acid plasma concentration in all toddlers and arachidonic acid concentrations in boys. Arachidonic acid intake was predictive for its plasma concentration in girls, whereas intake of 3 major n-3 species (eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) were predictive for their plasma concentrations in boys. FADS2 genotype and DNA methylation in toddlers were not related to plasma concentrations or food intakes, except for CpG8 methylation. Maternal FADS2 methylation was a predictor for the boys' α-linolenic acid intakes. This exploratory study suggests that maternal FADS2 genetic and epigenetic status could be related to toddlers' polyunsaturated fatty acid metabolism. Copyright © 2015 Elsevier Inc. All rights reserved.

Antimicrobial activity of fatty acid methyl esters of some members of Chenopodiaceae.

PubMed

Chandrasekaran, Manivachagam; Kannathasan, Krishnan; Venkatesalu, Venugopalan

2008-01-01

Fatty acid methyl ester (FAME) extracts of four halophytic plants, viz. Arthrocnemum indicum, Salicornia brachiata, Suaeda maritima and Suaeda monoica belonging to the family Chenopodiaceae, were prepared and their composition was analyzed by GC-MS. The FAME extracts were also screened for antibacterial and antifungal activities. The GC-MS analysis revealed the presence of more saturated fatty acids than unsaturated fatty acids. Among the fatty acids analyzed, the relative percentage of lauric acid was high in S. brachiata (61.85%). The FAME extract of S. brachiata showed the highest antibacterial and antifungal activities among the extracts tested. The other three extracts showed potent antibacterial and moderate anticandidal activities.

Methyl jasmonate stimulates biosynthesis of 2-phenylethylamine, phenylacetic acid and 2-phenylethanol in seedlings of common buckwheat.

PubMed

Horbowicz, Marcin; Wiczkowski, Wiesław; Sawicki, Tomasz; Szawara-Nowak, Dorota; Sytykiewicz, Hubert; Mitrus, Joanna

2015-01-01

Methyl jasmonate has a strong effect on secondary metabolizm in plants, by stimulating the biosynthesis a number of phenolic compounds and alkaloids. Common buckwheat (Fagopyrum esculentum Moench) is an important source of biologically active compounds. This research focuses on the detection and quantification of 2-phenylethylamine and its possible metabolites in the cotyledons, hypocotyl and roots of common buckwheat seedlings treated with methyl jasmonate. In cotyledons of buckwheat sprouts, only traces of 2-phenylethylamine were found, while in the hypocotyl and roots its concentration was about 150 and 1000-times higher, respectively. Treatment with methyl jasmonate resulted in a 4-fold increase of the 2-phenylethylamine level in the cotyledons of 7-day buckwheat seedlings, and an 11-fold and 5-fold increase in hypocotyl and roots, respectively. Methyl jasmonate treatment led also to about 4-fold increase of phenylacetic acid content in all examined seedling organs, but did not affect the 2-phenylethanol level in cotyledons, and slightly enhanced in hypocotyl and roots. It has been suggested that 2-phenylethylamine is a substrate for the biosynthesis of phenylacetic acid and 2-phenylethanol, as well as cinnamoyl 2-phenethylamide. In organs of buckwheat seedling treated with methyl jasmonate, higher amounts of aromatic amino acid transaminase mRNA were found. The enzyme can be involved in the synthesis of phenylpyruvic acid, but the presence of this compound could not be confirmed in any of the examined organs of common buckwheat seedling.

AVOIDING PITFALLS IN THE DETERMINATION OF HALOCARBOXYLIC ACIDS: THE PHOTOCHEMISTRY OF METHYLATION

EPA Science Inventory

Haloethanoic (haloacetic) acids are formed during chlorination of drinking water and are regulated by the Environmental Protection Agency (EPA). These compounds are normally quantified by gas chromatography with electron capture detection (GC-ECD) ad the methyl esters. EPA Meth...

Dietary and supplemental maternal methyl-group donor intake and cord blood DNA methylation.

PubMed

Pauwels, Sara; Ghosh, Manosij; Duca, Radu Corneliu; Bekaert, Bram; Freson, Kathleen; Huybrechts, Inge; A S Langie, Sabine; Koppen, Gudrun; Devlieger, Roland; Godderis, Lode

2017-01-02

Maternal nutrition is critically involved in the development and health of the fetus. We evaluated maternal methyl-group donor intake through diet (methionine, betaine, choline, folate) and supplementation (folic acid) before and during pregnancy in relation to global DNA methylation and hydroxymethylation and gene specific (IGF2 DMR, DNMT1, LEP, RXRA) cord blood methylation. A total of 115 mother-infant pairs were enrolled in the MAternal Nutrition and Offspring's Epigenome (MANOE) study. The intake of methyl-group donors was assessed using a food-frequency questionnaire. LC-MS/MS and pyrosequencing were used to measure global and gene specific methylation, respectively. Dietary intake of methyl-groups before and during pregnancy was associated with changes in LEP, DNMT1, and RXRA cord blood methylation. Statistically significant higher cord blood LEP methylation was observed when mothers started folic acid supplementation more than 6 months before conception compared with 3-6 months before conception (34.6 ± 6.3% vs. 30.1 ± 3.6%, P = 0.011, LEP CpG1) or no folic acid used before conception (16.2 ± 4.4% vs. 13.9 ± 3%, P = 0.036 for LEP CpG3 and 24.5 ± 3.5% vs. 22.2 ± 3.5%, P = 0.045 for LEP mean CpG). Taking folic acid supplements during the entire pregnancy resulted in statistically significantly higher cord blood RXRA methylation as compared with stopping supplementation in the second trimester (12.3 ± 1.9% vs. 11.1 ± 2%, P = 0.008 for RXRA mean CpG). To conclude, long-term folic acid use before and during pregnancy was associated with higher LEP and RXRA cord blood methylation, respectively. To date, pregnant women are advised to take a folic acid supplement of 400 µg/day from 4 weeks before until 12 weeks of pregnancy. Our results suggest significant epigenetic modifications when taking a folic acid supplement beyond the current advice.

Protonation-dissociation reactions of imazamethabenz-methyl and imazamethabenz-Acid in relation to their soil sorption and abiotic degradation.

PubMed

Pintado, Sara; Montoya, Mercedes Ruiz; Mellado, José Miguel Rodríguez

2009-12-09

This paper present ultraviolet-visible absorption spectra of imazamethabenz-methyl (IMBM) (mixture of the isomers methyl 6-[(RS)-4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl]-m-toluate, m-imazamethabenz, and methyl 2-[(RS)-4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl]-p-toluate, p-imazamethabenz) and the corresponding carboxylic acid, imazamethabenz-acid (IMBA). The spectral characteristics are determined as functions of the pH. The appreciable absorbance in the visible (or near-ultraviolet) region of the spectra indicates that the natural photolytic degradation is possible. From variations of the maximum absorbances of the bands, the pK values of 3.4 +/- 0.2 and 9.4 +/- 0.2 were obtained for protonation of the imidazol (=N-) nitrogen and dissociation of the NH imidazol nitrogen of IMBM, respectively. For IMBA, the dissociation pK of the carboxylic group is very close to that of the imidazol (=N-) nitrogen, both being close to 3.3. The dissociation pK of the NH imidazol nitrogen for IMBA is 9.6 +/- 0.2. The role of the acid-base reactions on the sorption on soils of these herbicides is discussed.

Photo degradation of methyl orange by attapulgite-SnO2-TiO2 nanocomposites.

PubMed

Zhang, Lili; Lv, Fujian; Zhang, Weiguang; Li, Rongqing; Zhong, Hui; Zhao, Yijiang; Zhang, Yu; Wang, Xin

2009-11-15

Photocatalytic removal of methyl orange under ultraviolet radiation has been studied using attapulgite (ATT) composites, which were synthesized by depositing SnO(2)-TiO(2) hybrid oxides on the surface of ATT to form a composite photocatalyst (denoted ATT-SnO(2)-TiO(2)) using an in situ sol-gel technique. Results showed that SnO(2)-TiO(2) nanocomposite particles with average size of about 10nm were loaded successfully on to the surface of ATT fibers and were widely dispersed. Correspondingly, the photocatalytic activity of ATT was improved significantly by loading SnO(2)-TiO(2). The photoactivity of the composite photocatalyst decreased in the sequence ATT-SnO(2)-TiO(2)>ATT-SnO(2)>ATT-TiO(2)>ATT. In order to achieve the best photocatalyst, the molar ratio of SnO(2) and TiO(2) in the ATT-SnO(2)-TiO(2) composites was adjusted to give a series with proportions r=n(Ti)/(n(Ti)+n(Sn))=0.0, 0.25, 0.33, 0.50, 0.67, 0.75, 0.80, 0.82, 0.86, 1.0. Results indicated that the proportion of SnO(2) and TiO(2) had a critical effect on the photocatalytic activity, which increased as the content of TiO(2) increased to r0.82. The highest degradation rate of methyl orange was 99% within 30 min obtained by using ATT-SnO(2)-TiO(2) with r=0.82. The repeated use of the composite photocatalyst was also confirmed.

Synthesis of fatty acid methyl ester from used vegetable cooking oil by solid reusable Mg 1-x Zn 1+x O2 catalyst.

PubMed

Olutoye, M A; Hameed, B H

2011-02-01

Fatty acid methyl ester was produced from used vegetable cooking oil using Mg(1-)(x) Zn(1+)(x)O(2) solid catalyst and the performance monitored in terms of ester content obtained. Used vegetable cooking oil was employed to reduce operation cost of biodiesel. The significant operating parameters which affect the overall yield of the process were studied. The highest ester content, 80%, was achieved with the catalyst during 4h 15 min reaction at 188°C with methanol to oil ratio of 9:1 and catalyst loading of 2.55 wt% oil. Also, transesterification of virgin oil gave higher yield with the heterogeneous catalyst and showed high selectivity towards ester production. The used vegetable cooking oil did not require any rigorous pretreatment. Catalyst stability was examined and there was no leaching of the active components, and its performance was as good at the fourth as at the first cycle. Copyright © 2010 Elsevier Ltd. All rights reserved.

VvMJE1 of the grapevine (Vitis vinifera) VvMES methylesterase family encodes for methyl jasmonate esterase and has a role in stress response

USDA-ARS?s Scientific Manuscript database

The known members of the plant methyl esterase (MES) family catalyze hydrolysis of a C-O ester linkage of methyl esters of several phytohormones including indole-3-acetic acid, salicylic acid, and jasmonic acid. The genome of grapevine (Vitis vinifera) was found to contain 15 MES genes, designated V...

Folic Acid Reduces Tau Phosphorylation by Regulating PP2A Methylation in Streptozotocin-Induced Diabetic Mice

PubMed Central

Zheng, Miaoyan; Zou, Chen; Li, Mengyue; Huang, Guowei; Gao, Yuxia; Liu, Huan

2017-01-01

High incidence rate of Alzheimer’s disease (AD) is observed in patients with type 2 diabetes. Aggregated β-amyloid (Aβ) and hyperphosphorylated tau are the hallmarks of AD. Hyperphosphorylated tau has been detected in diabetic animals as well as in diabetic patients. Folates mediate the transfer of one carbon unit, required in various biochemical reactions. The effect of folate on tau phosphorylation in diabetic models still remains unknown. In this study, we investigated the effect and mechanism of folic acid on hyperphosphorylation of tau in streptozotocin (STZ)-induced diabetic mice. Diabetic mice induced by STZ, at the age of 10 weeks, were administered with three levels of folic acid: folic acid-deficient diet, diet with normal folic acid content, and 120 μg/kg folic acid diet for 8 weeks. Levels of serum folate and blood glucose were monitored. Tau phosphorylation, protein phosphatase 2A (PP2A) methylation, and Glycogen synthase kinase 3β (GSK-3β) phosphorylation were detected using Western blot. The S-adenosyl methionine:S-adenosyl homocysteine ratio (SAM:SAH) in brain tissues was also determined. DNA methyltransferase (DNMT) mRNA expression levels were detected using real-time PCR. Folic acid reduced tau hyperphosphorylation at Ser396 in the brain of diabetes mellitus (DM) mice. In addition, PP2A methylation and DNMT1 mRNA expression were significantly increased in DM mice post folic acid treatment. GSK-3β phosphorylation was not regulated by folic acid administration. Folic acid can reduce tau phosphorylation by regulating PP2A methylation in diabetic mice. These results support that folic acid can serve as a multitarget neuronal therapeutic agent for treating diabetes-associated cognitive dysfunction. PMID:28422052

Preparation of fatty acid methyl esters from Osage orange (Maclura pomifera) oil and evaluation as biodiesel

USDA-ARS?s Scientific Manuscript database

Fatty acid methyl esters were prepared in high yield by transesterification of Osage orange (Maclura pomifera) oil. Extracted using supercritical CO2, the crude oil was initially treated with mineral acid and methanol to lower its content of free fatty acids, thus rendering it amenable to homogeneou...

Clinical Significance of Retinoic Acid Receptor Beta Promoter Methylation in Prostate Cancer: A Meta-Analysis.

PubMed

Dou, MengMeng; Zhou, XueLiang; Fan, ZhiRui; Ding, XianFei; Li, LiFeng; Wang, ShuLing; Xue, Wenhua; Wang, Hui; Suo, Zhenhe; Deng, XiaoMing

2018-01-01

Retinoic acid receptor beta (RAR beta) is a retinoic acid receptor gene that has been shown to play key roles during multiple cancer processes, including cell proliferation, apoptosis, migration and invasion. Numerous studies have found that methylation of the RAR beta promoter contributed to the occurrence and development of malignant tumors. However, the connection between RAR beta promoter methylation and prostate cancer (PCa) remains unknown. This meta-analysis evaluated the clinical significance of RAR beta promoter methylation in PCa. We searched all published records relevant to RAR beta and PCa in a series of databases, including PubMed, Embase, Cochrane Library, ISI Web of Science and CNKI. The rates of RAR beta promoter methylation in the PCa and control groups (including benign prostatic hyperplasia and normal prostate tissues) were summarized. In addition, we evaluated the source region of available samples and the methods used to detect methylation. To compare the incidence and variation in RAR beta promoter methylation in PCa and non-PCa tissues, the odds ratio (OR) and 95% confidence interval (CI) were calculated accordingly. All the data were analyzed with the statistical software STATA 12.0. Based on the inclusion and exclusion criteria, 15 articles assessing 1,339 samples were further analyzed. These data showed that the RAR beta promoter methylation rates in PCa tissues were significantly higher than the rates in the non-PCa group (OR=21.65, 95% CI: 9.27-50.57). Subgroup analysis according to the source region of samples showed that heterogeneity in Asia was small (I2=0.0%, P=0.430). Additional subgroup analysis based on the method used to detect RAR beta promoter methylation showed that the heterogeneity detected by MSP (methylation-specific PCR) was relatively small (I2=11.3%, P=0.343). Although studies reported different rates for RAR beta promoter methylation in PCa tissues, the total analysis demonstrated that RAR beta promoter methylation

Classification of bacteria by simultaneous methylation-solid phase microextraction and gas chromatography/mass spectrometry analysis of fatty acid methyl esters.

PubMed

Lu, Yao; Harrington, Peter B

2010-08-01

Direct methylation and solid-phase microextraction (SPME) were used as a sample preparation technique for classification of bacteria based on fatty acid methyl ester (FAME) profiles. Methanolic tetramethylammonium hydroxide was applied as a dual-function reagent to saponify and derivatize whole-cell bacterial fatty acids into FAMEs in one step, and SPME was used to extract the bacterial FAMEs from the headspace. Compared with traditional alkaline saponification and sample preparation using liquid-liquid extraction, the method presented in this work avoids using comparatively large amounts of inorganic and organic solvents and greatly decreases the sample preparation time as well. Characteristic gas chromatography/mass spectrometry (GC/MS) of FAME profiles was achieved for six bacterial species. The difference between Gram-positive and Gram-negative bacteria was clearly visualized with the application of principal component analysis of the GC/MS data of bacterial FAMEs. A cross-validation study using ten bootstrap Latin partitions and the fuzzy rule building expert system demonstrated 87 +/- 3% correct classification efficiency.

Olfactory Perception of Oviposition-Deterring Fatty Acids and Their Methyl Esters by the Asian Corn Borer, Ostrinia furnacalis

PubMed Central

Guo, Lei; Qing Li, Guo

2009-01-01

Olfactory perception of myristic, palmitic, stearic and oleic acids and their corresponding methyl esters by Asian corn borer moths, Ostrinia furnacalis (Guenée) (Lepidoptera: Crambidae) was investigated. It was found that mated females with both antennae amputated, in contrast to intact females and females with one antenna removed, could not discriminate between simultaneously provided control filter papers and filters treated with a blend of oviposition-deterring fatty acids. Oviposition by mated females exhibited a very marked periodicity, with all egg masses deposited during the scotophase and most egg masses laid before midnight. According to the peak and trough period of oviposition, electroantennogram (EAG) responses from both mated females and males to the four fatty acids and four methyl esters were tested within two two-hour periods from 3 to 5 hours after the start of darkness and from 1 to 3 hours after light onset, respectively. Significant EAG responses above solvent and background were elicited by all test chemicals from females, and by most of the test compounds from males. EAG values of all test chemicals from mated females were not statistically different between the two test periods except for methyl myristate. Conversely, EAG responses from mated males to myristic acid, stearic acid and their methyl esters significantly differed between the two test periods. PMID:20053122

Stereospecific enzymatic transformation of alpha-ketoglutarate to (2S,3R)-3-methyl glutamate during acidic lipopeptide biosynthesis.

PubMed

Mahlert, Christoph; Kopp, Florian; Thirlway, Jenny; Micklefield, Jason; Marahiel, Mohamed A

2007-10-03

The acidic lipopeptides, including the calcium-dependent antibiotics (CDA), daptomycin, and A54145, are important macrocyclic peptide natural products produced by Streptomyces species. All three compounds contain a 3-methyl glutamate (3-MeGlu) as the penultimate C-terminal residue, which is important for bioactivity. Here, biochemical in vitro reconstitution of the 3-MeGlu biosynthetic pathway is presented, using exclusively enzymes from the CDA producer Streptomyces coelicolor. It is shown that the predicted 3-MeGlu methyltransferase GlmT and its homologues DptI from the daptomycin producer Streptomyces roseosporus and LptI from the A54145 producer Streptomyces fradiae do not methylate free glutamic acid, PCP-bound glutamate, or Glu-containing CDA in vitro. Instead, GlmT, DptI, and LptI are S-adenosyl methionine (SAM)-dependent alpha-ketoglutarate methyltransferases that catalyze the stereospecific methylation of alpha-ketoglutarate (alphaKG) leading to (3R)-3-methyl-2-oxoglutarate. Subsequent enzyme screening identified the branched chain amino acid transaminase IlvE (SCO5523) as an efficient catalyst for the transformation of (3R)-3-methyl-2-oxoglutarate into (2S,3R)-3-MeGlu. Comparison of reversed-phase HPLC retention time of dabsylated 3-MeGlu generated by the coupled enzymatic reaction with dabsylated synthetic standards confirmed complete stereocontrol during enzymatic catalysis. This stereospecific two-step conversion of alphaKG to (2S,3R)-3-MeGlu completes our understanding of the biosynthesis and incorporation of beta-methylated amino acids into the nonribosomal lipopeptides. Finally, understanding this pathway may provide new possibilities for the production of modified peptides in engineered microbes.

Formation of molecular complexes of salicylic acid, acetylsalicylic acid, and methyl salicylate in a mixture of supercritical carbon dioxide with a polar cosolvent

NASA Astrophysics Data System (ADS)

Petrenko, V. E.; Antipova, M. L.; Gurina, D. L.; Odintsova, E. G.

2015-08-01

The solvate structures formed by salicylic acid, acetylsalicylic acid, and methyl salicylate in supercritical (SC) carbon dioxide with a polar cosolvent (methanol, 0.03 mole fractions) at a density of 0.7 g/cm3 and a temperature of 318 K were studied by the molecular dynamics method. Salicylic and acetylsalicylic acids were found to form highly stable hydrogen-bonded complexes with methanol via the hydrogen atom of the carboxyl group. For methyl salicylate in which the carboxyl hydrogen is substituted by a methyl radical, the formation of stable hydrogen bonds with methanol was not revealed. The contribution of other functional groups of the solute to the interactions with the cosolvent was much smaller. An analysis of correlations between the obtained data and the literature data on the cosolvent effect on the solubility of the compounds in SC CO2 showed that the dissolving ability of SC CO2 with respect to a polar organic substance in the presence of a cosolvent increased only when stable hydrogen-bonded complexes are formed between this substance and the cosolvent.

An enhanced procedure for measuring organic acids and methyl esters in PM2.5

NASA Astrophysics Data System (ADS)

Liu, F.; Duan, F. K.; He, K. B.; Ma, Y. L.; Rahn, K. A.; Zhang, Q.

2015-11-01

A solid-phase extraction (SPE) pretreatment procedure allowing organic acids to be separated from methyl esters in fine aerosol has been developed. The procedure first separates the organic acids from fatty acid methyl esters (FAMEs) and other nonacid organic compounds by aminopropyl-based SPE cartridge and then quantifies them by gas chromatography/mass spectrometry. The procedure prevents the fatty acids and dimethyl phthalate from being overestimated, and so allows us to accurately quantify the C4-C11 dicarboxylic acids (DCAs) and the C8-C30 monocarboxylic acids (MCAs). Results for the extraction of DCAs, MCAs, and AMAs in eluate and FAMEs in effluate by SAX and NH2 SPE cartridges exhibited that the NH2 SPE cartridge gave higher extraction efficiency than the SAX cartridge. The recoveries of analytes ranged from 67.5 to 111.3 %, and the RSD ranged from 0.7 to 10.9 %. The resulting correlations between the aliphatic acids and FAMEs suggest that the FAMEs had sources similar to those of the carboxylic acids, or were formed by esterifying carboxylic acids, or that aliphatic acids were formed by hydrolyzing FAMEs. Through extraction and cleanup using this procedure, 17 aromatic acids in eluate were identified and quantified by gas chromatography/tandem mass spectrometry, including five polycyclic aromatic hydrocarbon (PAH): acids 2-naphthoic, biphenyl-4-carboxylic, 9-oxo-9H-fluorene-1-carboxylic, biphenyl-4,4´-dicarboxylic, and phenanthrene-1-carboxylic acid, plus 1,8-naphthalic anhydride. Correlations between the PAH acids and the dicarboxylic and aromatic acids suggested that the first three acids and 1,8-naphthalic anhydride were secondary atmospheric photochemistry products and the last two mainly primary.

Site-Directed Mutagenesis of HgcA and HgcB Reveals Amino Acid Residues Important for Mercury Methylation

DOE PAGES

Smith, Steven D.; Bridou, Romain; Johs, Alexander; ...

2015-02-27

Methylmercury is a potent neurotoxin that is produced by anaerobic microorganisms from inorganic mercury by a recently discovered pathway. A two-gene cluster, consisting of hgcA and hgcB, encodes two of the proteins essential for this activity. hgcA encodes a corrinoid protein with a strictly conserved cysteine proposed to be the ligand for cobalt in the corrinoid cofactor, whereas hgcB encodes a ferredoxin-like protein thought to be an electron donor to HgcA. Deletion of either gene eliminates mercury methylation by the methylator Desulfovibrio desulfuricans ND132. Here, site-directed mutants of HgcA and HgcB were constructed to determine amino acid residues essential formore » mercury methylation. Mutations of the strictly conserved residue Cys93 in HgcA, the proposed ligand for the corrinoid cobalt, to Ala or Thr completely abolished the methylation capacity, but a His substitution produced measurable methylmercury. Mutations of conserved amino acids near Cys93 had various impacts on the methylation capacity but showed that the structure of the putative “cap helix” region harboring Cys93 is crucial for methylation function. In the ferredoxin-like protein HgcB, only one of two conserved cysteines found at the C terminus was necessary for methylation, but either cysteine sufficed. An additional, strictly conserved cysteine, Cys73, was also determined to be essential for methylation. Ultimately, this study supports the previously predicted importance of Cys93 in HgcA for methylation of mercury and reveals additional residues in HgcA and HgcB that facilitate the production of this neurotoxin.« less

Folic Acid Supplementation Delays Atherosclerotic Lesion Development by Modulating MCP1 and VEGF DNA Methylation Levels In Vivo and In Vitro

PubMed Central

Cui, Shanshan; Li, Wen; Lv, Xin; Wang, Pengyan; Gao, Yuxia; Huang, Guowei

2017-01-01

The pathogenesis of atherosclerosis has been partly acknowledged to result from aberrant epigenetic mechanisms. Accordingly, low folate levels are considered to be a contributing factor to promoting vascular disease because of deregulation of DNA methylation. We hypothesized that increasing the levels of folic acid may act via an epigenetic gene silencing mechanism to ameliorate atherosclerosis. Here, we investigated the atheroprotective effects of folic acid and the resultant methylation status in high-fat diet-fed ApoE knockout mice and in oxidized low-density lipoprotein-treated human umbilical vein endothelial cells. We analyzed atherosclerotic lesion histology, folate concentration, homocysteine concentration, S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH), and DNA methyltransferase activity, as well as monocyte chemotactic protein-1 (MCP1) and vascular endothelial growth factor (VEGF) expression and promoter methylation. Folic acid reduced atherosclerotic lesion size in ApoE knockout mice. The underlying folic acid protective mechanism appears to operate through regulating the normal homocysteine state, upregulating the SAM: SAH ratio, elevating DNA methyltransferase activity and expression, altering MCP1 and VEGF promoter methylation, and inhibiting MCP1 and VEGF expression. We conclude that folic acid supplementation effectively prevented atherosclerosis by modifying DNA methylation through the methionine cycle, improving DNA methyltransferase activity and expression, and thus changing the expression of atherosclerosis-related genes. PMID:28475147

40 CFR 721.10526 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, telomers with C18-26-alkyl acrylate, 1...

Code of Federal Regulations, 2013 CFR

2013-07-01

...-dodecanethiol, N-(hydroxymethyl)-2-methyl-2-propenamide, polyfluorooctyl methacrylate and vinylidene chloride, 2...-alkyl acrylate, 1-dodecanethiol, N-(hydroxymethyl)-2-methyl-2-propenamide, polyfluorooctyl methacrylate... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 2-Propenoic acid, 2-methyl-, 2...

40 CFR 721.10526 - 2-Propenoic acid, 2-methyl-, 2-hydroxyethyl ester, telomers with C18-26-alkyl acrylate, 1...

Code of Federal Regulations, 2014 CFR

2014-07-01

...-dodecanethiol, N-(hydroxymethyl)-2-methyl-2-propenamide, polyfluorooctyl methacrylate and vinylidene chloride, 2...-alkyl acrylate, 1-dodecanethiol, N-(hydroxymethyl)-2-methyl-2-propenamide, polyfluorooctyl methacrylate... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 2-Propenoic acid, 2-methyl-, 2...

Elicitor-Induced Association of Isoflavone O-Methyltransferase with Endomembranes Prevents the Formation and 7-O-Methylation of Daidzein during Isoflavonoid Phytoalexin Biosynthesis

PubMed Central

Liu, Chang-Jun; Dixon, Richard A.

2001-01-01

The bioactive isoflavonoids of the Leguminosae often are methylated on the 4′-position of their B-rings. Paradoxically, reverse genetic evidence implicates alfalfa isoflavone O-methyltransferase (IOMT) in the biosynthesis of 4′-O-methylated isoflavonoids such as the phytoalexin medicarpin in vivo, whereas biochemical studies indicate that IOMT has strict specificity for methylation of the A-ring 7-hydroxyl of daidzein, the presumed substrate for O-methylation, in vitro. Radiolabeling and isotope dilution studies now confirm that daidzein is not an intermediate in isoflavonoid phytoalexin biosynthesis in alfalfa. Furthermore, protein gel blot analysis and confocal microscopy of a transiently expressed IOMT–green fluorescent protein fusion in alfalfa leaves show that the operationally soluble IOMT localizes to endomembranes after elicitation of the isoflavonoid pathway. We propose that IOMT colocalizes with the endoplasmic reticulum–associated isoflavone synthase cytochrome P450 to ensure rapid B-ring methylation of the unstable 2,4′,7-trihydroxyisoflavanone product of isoflavone synthase, thereby preventing its dehydration to daidzein and subsequent A-ring methylation by free IOMT. In this way, metabolic channeling at the entry point into isoflavonoid phytoalexin biosynthesis protects an unstable intermediate from an unproductive metabolic conversion. PMID:11752378

Isolation and characterization of fatty acid methyl ester (FAME)-producing Streptomyces sp. S161 from sheep (Ovis aries) faeces.

PubMed

Lu, Y; Wang, J; Deng, Z; Wu, H; Deng, Q; Tan, H; Cao, L

2013-09-01

An actinomycete producing oil-like mixtures was isolated and characterized. The strain was isolated from sheep faeces and identified as Streptomyces sp. S161 based on 16S rRNA gene sequence analysis. The strain showed cellulase and xylanase activities. The (1) H nuclear magnetic resonance (NMR) spectra of the mixtures showed that the mixtures were composed of fatty acid methyl esters (52·5), triglycerides (13·7) and monoglycerides (9·1) (mol.%). Based on the gas chromatography-mass spectrometry (GC-MS) analysis, the fatty acid methyl esters were mainly composed of C14-C16 long-chain fatty acids. The results indicated that Streptomyces sp. S161 could produce fatty acid methyl esters (FAME) directly from starch. To our knowledge, this is the first isolated strain that can produce biodiesel (FAME) directly from starch. © 2013 The Society for Applied Microbiology.

CRISPRi-mediated metabolic engineering of E. coli for O-methylated anthocyanin production.

PubMed

Cress, Brady F; Leitz, Quentin D; Kim, Daniel C; Amore, Teresita D; Suzuki, Jon Y; Linhardt, Robert J; Koffas, Mattheos A G

2017-01-17

Anthocyanins are a class of brightly colored, glycosylated flavonoid pigments that imbue their flower and fruit host tissues with hues of predominantly red, orange, purple, and blue. Although all anthocyanins exhibit pH-responsive photochemical changes, distinct structural decorations on the core anthocyanin skeleton also cause dramatic color shifts, in addition to improved stabilities and unique pharmacological properties. In this work, we report for the first time the extension of the reconstituted plant anthocyanin pathway from (+)-catechin to O-methylated anthocyanins in a microbial production system, an effort which requires simultaneous co-option of the endogenous metabolites UDP-glucose and S-adenosyl-L-methionine (SAM or AdoMet). Anthocyanin O-methyltransferase (AOMT) orthologs from various plant sources were co-expressed in Escherichia coli with Petunia hybrida anthocyanidin synthase (PhANS) and Arabidopsis thaliana anthocyanidin 3-O-glucosyltransferase (At3GT). Vitis vinifera AOMT (VvAOMT1) and fragrant cyclamen 'Kaori-no-mai' AOMT (CkmOMT2) were found to be the most effective AOMTs for production of the 3'-O-methylated product peonidin 3-O-glucoside (P3G), attaining the highest titers at 2.4 and 2.7 mg/L, respectively. Following modulation of plasmid copy number and optimization of VvAOMT1 and CkmOMT2 expression conditions, production was further improved to 23 mg/L using VvAOMT1. Finally, CRISPRi was utilized to silence the transcriptional repressor MetJ in order to deregulate the methionine biosynthetic pathway and improve SAM availability for O-methylation of cyanidin 3-O-glucoside (C3G), the biosynthetic precursor to P3G. MetJ repression led to a final titer of 51 mg/L (56 mg/L upon scale-up to shake flask), representing a twofold improvement over the non-targeting CRISPRi control strain and 21-fold improvement overall. An E. coli strain was engineered for production of the specialty anthocyanin P3G using the abundant and comparatively

Gas chromatographic separation of fatty acid methyl esters on weakly polar capillary columns.

PubMed

Yamamoto, Kouhei; Kinoshita, Akemi; Shibahara, Akira

2008-02-22

It was found that weakly polar columns, routinely used in capillary GC for analyzing sterols, food additives, etc., can also be used for separating fatty acid methyl esters (FAMEs). On these columns, FAMEs elute in the order of their unsaturation. The equivalent chain-length value of methyl 22:6 is below 23.00. This means FAMEs within a carbon chain length, having up to six double bonds, elute before the next (one carbon longer) saturated FAME elutes. Peak identification is easy. Weakly polar columns are compatible in both GC and GC/MS systems.

Antioxidant activity of gallic acid and methyl gallate in triacylglycerols of Kilka fish oil and its oil-in-water emulsion.

PubMed

Asnaashari, Maryam; Farhoosh, Reza; Sharif, Ali

2014-09-15

The anti-DPPH radical effect as well as anti-peroxide activity of gallic acid, methyl gallate, and α-tocopherol in a bulk Kilka fish oil and its oil-in-water emulsion stabilized by soy protein isolate at 55°C were investigated. Gallic acid with the lowest hydrophobicity (log P=-0.28) was found to be the most active antiradical agent (IC50=29.5 μM), followed by methyl gallate (IC50=38.0 μM, log P=-0.23) and α-tocopherol (IC50=105.3 μM, log P=0.70). The anti-peroxide activity in the bulk oil system decreased in the order of methyl gallate>gallic acid>α-tocopherol. In the emulsion system, methyl gallate still behaved better than gallic acid, but the highest activity belonged to α-tocopherol. Based on the calculation of a number of kinetic parameters, the antioxidants, in general, showed better performances in the bulk oil system than in the emulsion system. Copyright © 2014 Elsevier Ltd. All rights reserved.

Conversion of beet molasses and cheese whey into fatty acid methyl esters by the yeast Cryptococcus curvatus.

PubMed

Takakuwa, Naoya; Saito, Katsuichi

2010-01-01

Eighty-one yeast isolates from raw milk were surveyed for the production of fatty acid methyl esters (FAME). Only one species, identified as Cryptococcus curvatus, produced FAME at a detectable level. Cr. curvatus TYC-19 produced more FAME from beet molasses and cheese whey medium than other strains of the same species. In both media, the major FAME produced were linoleic and oleic acid methyl esters. Sequence analysis of the internal transcribed spacer region of ribosomal DNA indicated that TYC-19 diverged from the same species.

Structure-activity relationship of daptomycin analogues with substitution at (2S, 3R) 3-methyl glutamic acid position.

PubMed

Lin, Du'an; Lam, Hiu Yung; Han, Wenbo; Cotroneo, Nicole; Pandya, Bhaumik A; Li, Xuechen

2017-02-01

Daptomycin is a highly effective lipopeptide antibiotic against Gram-positive pathogens. The presence of (2S, 3R) 3-methyl glutamic acid (mGlu) in daptomycin has been found to be important to the antibacterial activity. However the role of (2S, 3R) mGlu is yet to be revealed. Herein, we reported the syntheses of three daptomycin analogues with (2S, 3R) mGlu substituted by (2S, 3R) methyl glutamine (mGln), dimethyl glutamic acid and (2S, 3R) ethyl glutamic acid (eGlu), respectively, and their antibacterial activities. The detailed synthesis of dimethyl glutamic acid was also reported. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preparation of fatty acid methyl esters for gas-chromatographic analysis of marine lipids: insight studies.

PubMed

Carvalho, Ana P; Malcata, F Xavier

2005-06-29

Assays for fatty acid composition in biological materials are commonly carried out by gas chromatography, after conversion of the lipid material into the corresponding methyl esters (FAME) via suitable derivatization reactions. Quantitative derivatization depends on the type of catalyst and processing conditions employed, as well as the solubility of said sample in the reaction medium. Most literature pertinent to derivatization has focused on differential comparison between alternative methods; although useful to find out the best method for a particular sample, additional studies on factors that may affect each step of FAME preparation are urged. In this work, the influence of various parameters in each step of derivatization reactions was studied, using both cod liver oil and microalgal biomass as model systems. The accuracies of said methodologies were tested via comparison with the AOCS standard method, whereas their reproducibility was assessed by analysis of variance of (replicated) data. Alkaline catalysts generated lower levels of long-chain unsaturated FAME than acidic ones. Among these, acetyl chloride and BF(3) were statistically equivalent to each other. The standard method, which involves alkaline treatment of samples before acidic methylation with BF(3), provided equivalent results when compared with acidic methylation with BF(3) alone. Polarity of the reaction medium was found to be of the utmost importance in the process: intermediate values of polarity [e.g., obtained by a 1:1 (v/v) mixture of methanol with diethyl ether or toluene] provided amounts of extracted polyunsaturated fatty acids statistically higher than those obtained via the standard method.

40 CFR 721.304 - Acetic acid, [(5-chloro-8-quinolinyl)oxy-], 1-methyl hexyl ester.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Acetic acid, [(5-chloro-8-quinolinyl)oxy-], 1-methyl hexyl ester. 721.304 Section 721.304 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.304 Acetic acid, [(5-chloro-8-quinolinyl)oxy-], 1...

Fatty acid methyl ester analysis to identify sources of soil in surface water.

PubMed

Banowetz, Gary M; Whittaker, Gerald W; Dierksen, Karen P; Azevedo, Mark D; Kennedy, Ann C; Griffith, Stephen M; Steiner, Jeffrey J

2006-01-01

Efforts to improve land-use practices to prevent contamination of surface waters with soil are limited by an inability to identify the primary sources of soil present in these waters. We evaluated the utility of fatty acid methyl ester (FAME) profiles of dry reference soils for multivariate statistical classification of soils collected from surface waters adjacent to agricultural production fields and a wooded riparian zone. Trials that compared approaches to concentrate soil from surface water showed that aluminum sulfate precipitation provided comparable yields to that obtained by vacuum filtration and was more suitable for handling large numbers of samples. Fatty acid methyl ester profiles were developed from reference soils collected from contrasting land uses in different seasons to determine whether specific fatty acids would consistently serve as variables in multivariate statistical analyses to permit reliable classification of soils. We used a Bayesian method and an independent iterative process to select appropriate fatty acids and found that variable selection was strongly impacted by the season during which soil was collected. The apparent seasonal variation in the occurrence of marker fatty acids in FAME profiles from reference soils prevented preparation of a standardized set of variables. Nevertheless, accurate classification of soil in surface water was achieved utilizing fatty acid variables identified in seasonally matched reference soils. Correlation analysis of entire chromatograms and subsequent discriminant analyses utilizing a restricted number of fatty acid variables showed that FAME profiles of soils exposed to the aquatic environment still had utility for classification at least 1 wk after submersion.

Structural and Functional Characterization of a Novel Family GH115 4-O-Methyl-α-Glucuronidase with Specificity for Decorated Arabinogalactans.

PubMed

Aalbers, Friso; Turkenburg, Johan P; Davies, Gideon J; Dijkhuizen, Lubbert; Lammerts van Bueren, Alicia

2015-12-04

Glycoside hydrolases are clustered into families based on amino acid sequence similarities, and belonging to a particular family can infer biological activity of an enzyme. Family GH115 contains α-glucuronidases where several members have been shown to hydrolyze terminal α-1,2-linked glucuronic acid and 4-O-methylated glucuronic acid from the plant cell wall polysaccharide glucuronoxylan. Other GH115 enzymes show no activity on glucuronoxylan, and therefore, it has been proposed that family GH115 may be a poly-specific family. In this study, we reveal that a putative periplasmic GH115 from the human gut symbiont Bacteroides thetaiotaomicron, BtGH115A, hydrolyzes terminal 4-O-methyl-glucuronic acid residues from decorated arabinogalactan isolated from acacia tree. The three-dimensional structure of BtGH115A reveals that BtGH115A has the same domain architecture as the other structurally characterized member of this family, BoAgu115A; however the position of the C-terminal module is altered with respect to each individual enzyme. Phylogenetic analysis of GH115 amino sequences divides the family into distinct clades that may distinguish different substrate specificities. Finally, we show that BtGH115A α-glucuronidase activity is necessary for the sequential digestion of branched galactans from acacia gum by a galactan-β-1,3-galactosidase from family GH43; however, while B. thetaiotaomicron grows on larch wood arabinogalactan, the bacterium is not able to metabolize acacia gum arabinogalactan, suggesting that BtGH115A is involved in degradation of arabinogalactan fragments liberated by other microbial species in the gastrointestinal tract. Copyright © 2015 Elsevier Ltd. All rights reserved.

Efficient and scalable synthesis of bardoxolone methyl (cddo-methyl ester).

PubMed

Fu, Liangfeng; Gribble, Gordon W

2013-04-05

Bardoxolone methyl (2-cyano-3,12-dioxooleane-1,9(11)-dien-28-oic acid methyl ester; CDDO-Me) (1), a synthetic oleanane triterpenoid with highly potent anti-inflammatory activity (levels below 1 nM), has completed a successful phase I clinical trial for the treatment of cancer and a successful phase II trial for the treatment of chronic kidney disease in type 2 diabetes patients. Our synthesis of bardoxolone methyl (1) proceeds in ∼50% overall yield in five steps from oleanolic acid (2), requires only one to two chromatographic purifications, and can provide gram quantities of 1.

An enantioselective route to alpha-methyl carboxylic acids via metal and enzyme catalysis.

PubMed

Norinder, Jakob; Bogár, Krisztián; Kanupp, Lisa; Bäckvall, Jan-E

2007-11-22

Dynamic kinetic resolution of allylic alcohols to allylic acetates followed by copper-catalyzed allylic substitution gave alkenes in high yields and high optical purity. Subsequent oxidative C-C double bond cleavage afforded pharmaceutically important alpha-methyl substituted carboxylic acids in high ee.

PLASMID DNA DAMAGE CAUSED BY METHYLATED ARSENICALS, ASCORBIC ACID AND HUMAN LIVER FERRITIN

EPA Science Inventory

Plasmid DNA damage caused by methylated arsenicals, ascorbic acid and human liver ferritin.

Arsenic causes cancer in human skin, urinary bladder, lung, liver and kidney and is a significant world-wide public health problem. Although the metabolism of inorganic arsenic is ...

Determination of fatty acid methyl esters derived from algae Scenedesmus dimorphus biomass by GC-MS with one-step esterification of free fatty acids and transesterification of glycerolipids.

PubMed

Avula, Satya Girish Chandra; Belovich, Joanne M; Xu, Yan

2017-05-01

Algae can synthesize, accumulate and store large amounts of lipids in its cells, which holds immense potential as a renewable source of biodiesel. In this work, we have developed and validated a GC-MS method for quantitation of fatty acids and glycerolipids in forms of fatty acid methyl esters derived from algae biomass. Algae Scenedesmus dimorphus dry mass was pulverized by mortar and pestle, then extracted by the modified Folch method and fractionated into free fatty acids and glycerolipids on aminopropyl solid-phase extraction cartridges. Fatty acid methyl esters were produced by an optimized one-step esterification of fatty acids and transesterification of glycerolipids with boron trichloride/methanol. The matrix effect, recoveries and stability of fatty acids and glycerolipids in algal matrix were first evaluated by spiking stable isotopes of pentadecanoic-2,2-d 2 acid and glyceryl tri(hexadecanoate-2,2-d 2 ) as surrogate analytes and tridecanoic-2,2-d 2 acid as internal standard into algal matrix prior to sample extraction. Later, the method was validated in terms of lower limits of quantitation, linear calibration ranges, intra- and inter-assay precision and accuracy using tridecanoic-2,2-d 2 acid as internal standard. The method developed has been applied to the quantitation of fatty acid methyl esters from free fatty acid and glycerolipid fractions of algae Scenedesmus dimorphus. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experimental and theoretical studies of the molecular structure of 7-Methyl-3-[(3-methyl-3-mesityl-cyclobutyl]-5-phenyl-5H-thiazolo[3,2-α]pyrimidine-6-carboxylic acid ethyl ester

NASA Astrophysics Data System (ADS)

Acar, Betül; Yilmaz, Ibrahim; Çalışkan, Nezihe; Cukurovali, Alaaddin

2017-07-01

In this work, the title molecule, 7-Methyl-3-[(3-methyl-3-mesityl-cyclobutyl]-5-phenyl-5H-thiazolo[3,2-α]pyrimidine-6-carboxylic acid ethyl ester (C30H34N2O2S1), was synthesized and characterized by FT-IR spectroscopy and single crystal X-ray diffraction. The compound crystallizes in the triclinic space group P21/c. with Z = 4, a = 14.1988(6), b = 19.0893(5), c = 10.1325(4) Å, V = 2674.56(17) A3. The optimized structure parameters of the studied molecule was determined theoretically using HF/6-31G(d) and B3LYP/6-31G(d) methods for ground state, and compared with previously reported experimental findings. The calculated harmonic vibrational frequencies are scaled and they are compared with experimental frequencies obtained by FT-IR spectra. The electronic properties, such as HOMO and LUMO energies, and molecular electrostatic potential (MEP) are also performed.

Biosynthesis of estragole and methyl-eugenol in sweet basil (Ocimum basilicum L). Developmental and chemotypic association of allylphenol O-methyltransferase activities.

PubMed

Lewinsohn, E; Ziv-Raz, I; Dudai, N; Tadmor, Y; Lastochkin, E; Larkov, O; Chaimovitsh, D; Ravid, U; Putievsky, E; Pichersky, E; Shoham, Y

2000-12-07

Sweet basil (Ocimum basilicum L., Lamiaceae) is a common herb, used for culinary and medicinal purposes. The essential oils of different sweet basil chemotypes contain various proportions of the allyl phenol derivatives estragole (methyl chavicol), eugenol, and methyl eugenol, as well as the monoterpene alcohol linalool. To monitor the developmental regulation of estragole biosynthesis in sweet basil, an enzymatic assay for S-adenosyl-L-methionine (SAM):chavicol O-methyltransferase activity was developed. Young leaves display high levels of chavicol O-methyltransferase activity, but the activity was negligible in older leaves, indicating that the O-methylation of chavicol primarily occurs early during leaf development. The O-methyltransferase activities detected in different sweet basil genotypes differed in their substrate specificities towards the methyl acceptor substrate. In the high-estragole-containing chemotype R3, the O-methyltransferase activity was highly specific for chavicol, while eugenol was virtually not O-methylated. In contrast, chemotype 147/97, that contains equal levels of estragole and methyl eugenol, displayed O-methyltransferase activities that accepted both chavicol and eugenol as substrates, generating estragole and methyl eugenol, respectively. Chemotype SW that contains high levels of eugenol, but lacks both estragole and methyl eugenol, had apparently no allylphenol dependent O-methyltransferase activities. These results indicate the presence of at least two types of allylphenol-specific O-methyltransferase activities in sweet basil chemotypes, one highly specific for chavicol; and a different one that can accept eugenol as a substrate. The relative availability and substrate specificities of these O-methyltransferase activities biochemically rationalizes the variation in the composition of the essential oils of these chemotypes.

Parthenolide accumulation and expression of genes related to parthenolide biosynthesis affected by exogenous application of methyl jasmonate and salicylic acid in Tanacetum parthenium.

PubMed

Majdi, Mohammad; Abdollahi, Mohammad Reza; Maroufi, Asad

2015-11-01

Up-regulation of germacrene A synthase and down-regulation of parthenolide hydroxylase genes play key role in parthenolide accumulation of feverfew plants treated with methyl jasmonate and salicylic acid. Parthenolide is an important sesquiterpene lactone due to its anti-migraine and anti-cancer properties. Parthenolide amount was quantified by high-performance liquid chromatography after foliar application of methyl jasmonate (100 µM) or salicylic acid (1.0 mM) on feverfew leaves in time course experiment (3-96 h). Results indicate that exogenous application of methyl jasmonate or salicylic acid activated parthenolide biosynthesis. Parthenolide content reached its highest amount at 24 h after methyl jasmonate or salicylic acid treatments, which were 3.1- and 1.96-fold higher than control plants, respectively. Parthenolide transiently increased due to methyl jasmonate or salicylic acid treatments until 24 h, but did not show significant difference compared with control plants at 48 and 96 h time points in both treatments. Also, the transcript levels of early pathway (upstream) genes of terpene biosynthesis including 3-hydroxy-3-methylglutaryl-coenzyme A reductase, 1-deoxy-D-xylulose-5-phosphate reductoisomerase and hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase and the biosynthetic genes of parthenolide including germacrene A synthase, germacrene A oxidase, costunolide synthase and parthenolide synthase were increased by methyl jasmonate and salicylic acid treatments, but with different intensity. The transcriptional levels of these genes were higher in methyl jasmonate-treated plants than salicylic acid-treated plants. Parthenolide content measurements along with expression pattern analysis of the aforementioned genes and parthenolide hydroxylase as side branch gene of parthenolide suggest that the expression patterns of early pathway genes were not directly consistent with parthenolide accumulation pattern; hence, parthenolide accumulation is

Genome-wide methylation and gene expression changes in newborn rats following maternal protein restriction and reversal by folic acid.

PubMed

Altobelli, Gioia; Bogdarina, Irina G; Stupka, Elia; Clark, Adrian J L; Langley-Evans, Simon

2013-01-01

A large body of evidence from human and animal studies demonstrates that the maternal diet during pregnancy can programme physiological and metabolic functions in the developing fetus, effectively determining susceptibility to later disease. The mechanistic basis of such programming is unclear but may involve resetting of epigenetic marks and fetal gene expression. The aim of this study was to evaluate genome-wide DNA methylation and gene expression in the livers of newborn rats exposed to maternal protein restriction. On day one postnatally, there were 618 differentially expressed genes and 1183 differentially methylated regions (FDR 5%). The functional analysis of differentially expressed genes indicated a significant effect on DNA repair/cycle/maintenance functions and of lipid, amino acid metabolism and circadian functions. Enrichment for known biological functions was found to be associated with differentially methylated regions. Moreover, these epigenetically altered regions overlapped genetic loci associated with metabolic and cardiovascular diseases. Both expression changes and DNA methylation changes were largely reversed by supplementing the protein restricted diet with folic acid. Although the epigenetic and gene expression signatures appeared to underpin largely different biological processes, the gene expression profile of DNA methyl transferases was altered, providing a potential link between the two molecular signatures. The data showed that maternal protein restriction is associated with widespread differential gene expression and DNA methylation across the genome, and that folic acid is able to reset both molecular signatures.

Characterization of a Bvg-regulated fatty acid methyl-transferase in Bordetella pertussis.

PubMed

Rivera-Millot, Alex; Lesne, Elodie; Solans, Luis; Coutte, Loic; Bertrand-Michel, Justine; Froguel, Philippe; Dhennin, Véronique; Hot, David; Locht, Camille; Antoine, Rudy; Jacob-Dubuisson, Françoise

2017-01-01

The whooping cough agent Bordetella pertussis controls the expression of its large virulence regulon in a coordinated manner through the two-component signal transduction system BvgAS. In addition to the genes coding for bona fide virulence factors, the Bvg regulon comprises genes of unknown function. In this work, we characterized a new Bvg-activated gene called BP2936. Homologs of BP2936 are found in other pathogenic Bordetellae and in several other species, including plant pathogens and environmental bacteria. We showed that the gene product of BP2936 is a membrane-associated methyl-transferase of free fatty acids. We thus propose to name it FmtB, for fatty acid methyl-transferase of Bordetella. The role of this protein was tested in cellular and animal models of infection, but the loss of BP2936 did not appear to affect host-pathogen interactions in those assays. The high level of conservation of BP2936 among B. pertussis isolates nevertheless argues that it probably plays a role in the life cycle of this pathogen.

Characterization of a Bvg-regulated fatty acid methyl-transferase in Bordetella pertussis

PubMed Central

Rivera-Millot, Alex; Lesne, Elodie; Solans, Luis; Coutte, Loic; Bertrand-Michel, Justine; Froguel, Philippe; Dhennin, Véronique; Hot, David; Locht, Camille; Antoine, Rudy

2017-01-01

The whooping cough agent Bordetella pertussis controls the expression of its large virulence regulon in a coordinated manner through the two-component signal transduction system BvgAS. In addition to the genes coding for bona fide virulence factors, the Bvg regulon comprises genes of unknown function. In this work, we characterized a new Bvg-activated gene called BP2936. Homologs of BP2936 are found in other pathogenic Bordetellae and in several other species, including plant pathogens and environmental bacteria. We showed that the gene product of BP2936 is a membrane-associated methyl-transferase of free fatty acids. We thus propose to name it FmtB, for fatty acid methyl-transferase of Bordetella. The role of this protein was tested in cellular and animal models of infection, but the loss of BP2936 did not appear to affect host-pathogen interactions in those assays. The high level of conservation of BP2936 among B. pertussis isolates nevertheless argues that it probably plays a role in the life cycle of this pathogen. PMID:28493897

Facile Fabrication of Cu2O Nanobelts in Ethanol on Nanoporous Cu and Their Photodegradation of Methyl Orange

PubMed Central

Yang, Yulin; Qin, Fengxiang; Wang, Hao; Chang, Hui

2018-01-01

Thin cupric oxide (Cu2O) nanobelts with width of few tens of nanometers to few hundreds of nanometers were fabricated in anhydrous ethanol on nanoporous copper templates that was prepared via dealloying amorphous Ti40Cu60 ribbons in hydrofluoric acid solutions at 348 K. The Cu2O octahedral particles preferentially form in the water, and nanobelts readily undergo the growth along the lengthwise and widthwise in the anhydrous ethanol. The ethanol molecules serve as stabilizing or capping reagents, and play a key role of the formation of two-dimensional Cu2O nanobelts. Cu atoms at weak sites (i.e., twin boundary) on the nanoporous Cu ligaments are ionized to form Cu2+ cations, and then react with OH− to form Cu2O and H2O. The two-dimensional growth of Cu2O nanostructure is preferred in anhydrous ethanol due to the suppression of random growth of Cu2O nanoarchitectures by ethanol. Cu2O nanobelts have superior photodegradation performance of methyl orange, three times higher than nanoporous Cu. PMID:29562692

Genetic Manipulation of Isoflavone 7-O-Methyltransferase Enhances Biosynthesis of 4′-O-Methylated Isoflavonoid Phytoalexins and Disease Resistance in Alfalfa

PubMed Central

He, Xian-Zhi; Dixon, Richard A.

2000-01-01

4′-O-Methylation of an isoflavonoid intermediate is a key reaction in the biosynthesis of the phytoalexin medicarpin in legumes. However, isoflavone O-methyltransferase (IOMT) from alfalfa converts the isoflavone daidzein to 7-O-methyl daidzein (isoformononetin) in vitro as well as in vivo in unchallenged leaves of transgenic alfalfa ectopically expressing IOMT. In contrast, elicitation of IOMT-overexpressing plants with CuCl2 or infecting these plants with Phoma medicaginis leads to greater accumulation of formononetin (4′-O-methyl daidzein) and medicarpin in the leaves than does elicitation or infection of control plants, and no isoformononetin is detected. Overexpression of IOMT results in increased induction of phenylpropanoid/isoflavonoid pathway gene transcripts after infection but has little effect on basal expression of these genes. IOMT-overexpressing plants display resistance to P. medicaginis. The apparently different regiospecificities of IOMT in vivo and in vitro are discussed in relation to potential metabolic channeling at the entry point into the isoflavonoid pathway. PMID:11006341

Nanosized CuO and ZnO Catalyst Supported on Honeycomb-Typed Monolith for Hydrogenation of Carbon Dioxide to Methyl Alcohol.

PubMed

Park, Chul-Min; Ahn, Won-Ju; Jo, Woong-Kyu; Song, Jin-Hun; Oh, Chang-Yeop; Jeong, Young-Shin; Chung, Min-Chul; Park, Kwon-Pil; Kim, Ki-Joong; Jeong, Woon-Jo; Sohn, Bo-Kyun; Jung, Sang-Chul; Lee, Do-Jin; Ahn, Byeong-Kwon; Ahn, Ho-Geun

2015-01-01

The greenhouse effect of carbon dioxide (CO2) has been recognized as one of the most serious problems in the world. Conversion of CO2 to methyl alcohol (CH3OH) was studied using catalytic chemical methods. Honeycomb-typed monolith used as catalyst support was 400 cell/inch2. Pretreatment of the monolith surface was carried out by thermal treatment and acid treatment. Monolith-supported nanosized CuO-ZnO catalysts were prepared by wash-coat method. The prepared catalysts were characterized by using SEM, TEM, and XRD. The catalytic activity for CO2 hydrogenation to CH3OH was investigated using a flow-type reactor with varying reaction temperature, reaction pressure and contact time. Conversion of CO2 was increased with increasing reaction temperature, but selectivity to CH3OH was decreased. Optimum reaction temperature was about 250 degrees C under 20 atm. Because of the reverse water gas shift reaction.

Utilization of crude karanj (Pongamia pinnata) oil as a potential feedstock for the synthesis of fatty acid methyl esters.

PubMed

Khayoon, M S; Olutoye, M A; Hameed, B H

2012-05-01

Methyl esters were synthesized from crude karanj oil (CKO) by single step esterification with methanol using sulfuric acid (H(2)SO(4)) and phosphoric acid (H(3)PO(4)) as catalysts in a homogeneous batch process. H(3)PO(4) was less active than H(2)SO(4) during the process as it presented very low ester yields (<20%) for the various molar ratios of fatty acid to alcohol studied. With H(2)SO(4) as catalyst, the yield was as high as 89.8% at 65°C after 5h. The fatty acids profile of the oil (palmitic acid: ≈ 12%; stearic acid: ≈ 8%; oleic acid: ≈ 52% and linolenic acid of 17%) and the different reactivities of the acids were responsible for the observed differences in conversion to methyl esters. The findings attained with this study might contribute to the economic utilization of a non-edible feedstock. Copyright © 2012 Elsevier Ltd. All rights reserved.

Solubility and diffusivity of N{sub 2}O and CO{sub 2} in (diethanolamine + N-methyldiethanolamine + water) and in (diethanolamine + 2-amino-2-methyl-1-propanol + water)

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

Li, M.H.; Lee, W.C.

1996-05-01

Acid gases such as CO{sub 2} and H{sub 2}S are frequently removed from natural gas, synthetic natural gas, and other process gas streams by means of absorption into aqueous alkanol-amine solutions. The solubility and diffusivity of N{sub 2}O in (diethanolamine + N-methyldiethanolamine + water) and in (diethanolamine + 2-amino-2-methyl-1-propanol + water) were measured at (30, 35, and 40)C and at atmospheric pressure. Five (diethanolamine + N-methyldiethanolamine + water) and four (diethanolamine + 2-amino-2-methyl-1-propanol + water) systems were studied. The total amine mass percent in all cases was 30. A solubility apparatus was used to measure the solubility of N{sub 2}Omore » in amine solutions. The diffusivity was measured by a wetted wall column absorber. The N{sub 2}O analogy was used to estimate the solubility and diffusivity of CO{sub 2} in (diethanolamine + N-methyldiethanolamine + water) and in (diethanolamine + 2-amino-2-methyl-1-propanol + water).« less

Effects of P/Ni ratio and Ni content on performance of γ-Al2O3-supported nickel phosphides for deoxygenation of methyl laurate to hydrocarbons

NASA Astrophysics Data System (ADS)

Zhang, Zhena; Tang, Mingxiao; Chen, Jixiang

2016-01-01

γ-Al2O3-supported nickel phosphides (mNi-Pn) were prepared by the TPR method and tested for the deoxygenation of methyl laurate to hydrocarbons. The effects of the P/Ni ratio (n = 1.0-2.5) and Ni content (m = 5-15 wt.%) in the precursors on their structure and performance were investigated. Ni/γ-Al2O3 was also studied for comparison. It was found that the formation of AlPO4 in the precursor inhibited the reduction of phosphate and so the formation of nickel phosphides. With increasing the P/Ni ratio and Ni content, the Ni, Ni3P, Ni12P5 and Ni2P phases orderly formed, accompanying with the increases of their particle size and the amount of weak acid sites (mainly due to P-OH group), while the CO uptake and the amount of medium strong acid sites (mainly related to Ni sites) reached maximum on 10%Ni-P1.5. In the deoxygenation reaction, compared with Ni/γ-Al2O3, the mNi-Pn catalysts showed much lower activities for decarbonylation, Csbnd C hydrogenolysis and methanation due to the ligand and ensemble effects of P. The conversion and the selectivity to n-C11 and n-C12 hydrocarbons achieved maximum on 10%Ni-P 2.0 for the 10%Ni-Pn catalysts and on 8%Ni-P2.0 for the mNi-P2.0 catalysts, while the turnover frequency (TOF) of methyl laurate mainly increased with the P/Ni ratio and Ni content. We propose that TOF was influenced by the nickel phosphide phases, the catalyst acidity and the particle size as well as the synergetic effect between the Ni site and acid site. Again, the hydrodeoxygenation pathway of methyl laurate was promoted with increasing P/Ni ratio and Ni content, ascribed to the phase change in the order of Ni, Ni3P, Ni12P5 and Ni2P in the prepared catalysts.

Synthesis of N-oleyl O-sulfate chitosan from methyl oleate with O-sulfate chitosan as edible film material

NASA Astrophysics Data System (ADS)

Daniel; Sihaloho, O.; Saleh, C.; Magdaleni, A. R.

2018-04-01

The research on the synthesis of N-oleyl O-sulfate chitosan through sulfonation reaction on chitosan with ammonium sulfate and followed by amidation reaction using methyl oleate has been done. In this study, chitosan was chemically modified into N-oleyl O-sulfatechitosan as an edible film making material. N-oleyl O-sulfate chitosan was synthesized by reaction between methyl oleate and O-sulfate chitosan. Wherein the depleted chitosan of O-sulfate chitosan into O-sulfate chitosan was obtained by reaction of sulfonation between ammonium sulfate and chitosan aldimine. While chitosan aldimine was obtained through reaction between chitosan with acetaldehyde. The structure of N-oleyl O-sulfate chitosan was characterized by FT-IR analysis which showed vibration uptake of C-H sp3 group, S=O group, and carbonyl group C=O of the ester. The resulting of N-oleyl O-sulfate chitosan yielded a percentage of 93.52%. Hydrophilic-Lipophilic Balance (HLB) test results gave a value of 6.68. In the toxicity test results of N-oleyl O-sulfate chitosan obtained LC50 value of 3738.4732 ppm. In WVTR (Water Vapor Transmission Rate) test results for chitosan film was 407.625 gram/m2/24 hours and N-oleylO-sulfate chitosan film was 201.125 gram/m2/24 hours.

Biosynthesis of 8-O-methylated benzoxazinoid defense compounds in maize

USDA-ARS?s Scientific Manuscript database

Benzoxazinoids are important defense compounds in grasses. Here, we investigated the biosynthesis and biological roles of the 8-O-methylated benzoxazinoids, DIM2BOA-Glc and HDM2BOA-Glc. Using quantitative trait locus mapping and heterologous expression, we identified a 2-oxoglutarate-dependent dioxy...

Correlating the cold flow and melting properties of fatty acid methyl ester (FAME) mixtures

USDA-ARS?s Scientific Manuscript database

Fatty acid methyl ester (FAME) mixtures derived from plant oils or animal fats are used to make biodiesel, lubricants, surfactants, plasticizers, ink solvents, paint strippers and other products. Processing requires a precise knowledge of the physico-chemical properties of mixtures with diverse and ...

Adsorption Isotherm Studies of Methyl Bromide on MgO

NASA Astrophysics Data System (ADS)

Burns, Teresa; Larese, John

2003-11-01

The adsorption of methyl bromine onto highly-uniform magnesium oxide powder was studied using a high-precision computer-controlled gas adsorption system. Methyl bromide was condensed onto the MgO substrate at temperatures between 165 K and 180 K. The layering behavior, iosthermal compressibility, and isosteric heat of adsorption were determined. Isotherms will be presented and future work discussed. TEB research sponsored by the Department of Energy EPSCOR Grant No. DE-FG02-01ER45895. JZL research sponsored by start-up funds from the University of Tennessee - Knoxville and by the Division of Materials Sciences, Office of Basic Energy Sciences, U.S. Department of Energy, under contract No. DE-AC05-00OR22725 with Oak Ridge National Laboratory, managed and operated by UT-Battelle, LLC.

Efficient procedure for isolating methylated catechins from green tea and effective simultaneous analysis of ten catechins, three purine alkaloids, and gallic acid in tea by high-performance liquid chromatography with diode array detection.

PubMed

Hu, Bing; Wang, Lin; Zhou, Bei; Zhang, Xin; Sun, Yi; Ye, Hong; Zhao, Liyan; Hu, Qiuhui; Wang, Guoxiang; Zeng, Xiaoxiong

2009-04-10

Monomers of (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCG), (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin 3-O-(3-O-methyl) gallate (EGCG3''Me) and (-)-3-O-methyl epicatechin gallate (ECG3'Me) (purity, >97%) were successfully prepared from extract of green tea by two-time separation with Toyopearl HW-40S column chromatography eluted by 80% ethanol. In addition, monomers of (-)-catechin (C), (-)-gallocatechin (GC), (-)-gallocatechin gallate (GCG), and (-)-catechin gallate (CG) (purity, >98%) were prepared from EC, EGC, EGCG, and ECG by heat-epimerization and semi-preparative HPLC chromatography. With the prepared catechin standards, an effective and simultaneous HPLC method for the analysis of gallic acid, tea catechins, and purine alkaloids in tea was developed in the present study. Using an ODS-100Z C(18) reversed-phase column, fourteen compounds were rapidly separated within 15min by a linear gradient elution of formic acid solution (pH 2.5) and methanol. A 2.5-7-fold reduction in HPLC analysis time was obtained from existing analytical methods (40-105min) for gallic acid, tea catechins including O-methylated catechins and epimers of epicatechins, as well as purine alkaloids. Detection limits were generally on the order of 0.1-1.0ng for most components at the applied wavelength of 280nm. Method replication generally resulted in intraday and interday peak area variation of <6% for most tested components in green, Oolong, black, and pu-erh teas. Recovery rates were generally within the range of 92-106% with RSDs less than 4.39%. Therefore, advancement has been readily achievable with commonly used chromatography equipments in the present study, which will facilitate the analytical, clinical, and other studies of tea catechins.

Analysis of Chemical Signatures of Alkaliphiles using Fatty Acid Methyl Ester Analysis

PubMed Central

Sreenivasulu, Basha; Paramageetham, Chinthala; Sreenivasulu, Dasari; Suman, Bukke; Umamahesh, Katike; Babu, Gundala Prasada

2017-01-01

Background: Fatty acids occur in nearly all living organisms as the important predominant constituents of lipids. While all fatty acids have essentially the same chemical nature, they are an extremely diverse group of compounds. Materials and Methods: To test the hypothesis, fatty acids of alkaliphiles isolates, Bacillus subtilis SVUNM4, Bacillus licheniformis SVUNM8, Bacillus methylotrohicus SVUNM9, and Paenibacillus dendritiformis SVUNM11, were characterized compared using gas chromatography-mass spectrometry (GC-MS) analysis. Results: The content of investigated ten fatty acids, 1, 2-benzenedicarboxylic acid butyl 2-methylpropyl ester, phthalic acid, isobutyl 2-pentyl ester, dibutyl phthalate, cyclotrisiloxane, hexamethyl, cyclotetrasiloxane, octamethyl, dodecamethyl, heptasiloxane 1,1,3,3,5,5,7,7,9,9,11,11,13,13-etradecamethyl, 7,15-dihydroxydehydroabietic acid, methyl ester, di (trimethylsilyl) ether, hentriacontane, 2-thiopheneacetic acid, undec-2-enyl ester, obviously varied among four species, suggesting each species has its own fatty acid pattern. Conclusions: These findings demonstrated that GC-MS-based fatty acid profiling analysis provides the reliable platform to classify these four species, which is helpful for ensuring their biotechnological interest and novel chemotaxonomic. PMID:28717333

Formation of dimethylarsinic acid from methylation of sodium arsenite in lumbricus terrestris.

PubMed

Lin, K W; Behl, S; Furst, A; Chien, P; Toia, R F

1998-04-01

Arsenic is ubiquitous in the environment and the toxicological response of various organisms to it is dependent on the particular chemical form involved. In general, methylation of inorganic arsenic is considered to be a detoxification reaction. While this transformation is known to be mediated by methyltransferases in several species of mammals, less is known about the fate of arsenic in invertebrates. As part of a continuing interest in heavy metals and metalloid toxicology, the alkylating activity of cytosol prepared from the common earthworm, Lumbricus terrestris, towards sodium arsenite has now been investigated. Thus, S-adenosyl-l-[(14)C]methionine ([(14)C-methyl]SAM) fortified earthworm cytosol was incubated with sodium arsenite at 37 degrees C for 90 min. Initial TLC analysis of the incubation mixture suggested incorporation of radiolabel into dimethylarsinic acid. This was subsequently proven by isolation of the metabolite through radiodilution followed by recrystallization of the recovered material to constant specific activity. This result suggests that earthworm cytosol has the same methylating reactivity towards arsenite as do similar preparations from various tissues of several species of mammals.

Gas chromatographic-mass spectrometric determination of alkylphosphonic acids from aqueous samples by ion-pair solid-phase extraction on activated charcoal and methylation.

PubMed

Vijaya Saradhi, U V R; Prabhakar, S; Jagadeshwar Reddy, T; Murty, M R V S

2007-07-20

In the present paper, we report an improved ion-pair solid-phase extraction (IP-SPE) method for the analysis of alkylphosphonic acids, namely, methyl, ethyl and propylphosphonic acids, present in the aqueous sample. The aqueous sample was mixed with an ion-pair reagent, phenyltrimethylammonium hydroxide (PTMAH) and passed through activated charcoal SPE cartridge. The retained chemicals in the cartridge were extracted with methanol and analysed by gas chromatography-mass spectrometry (GC-MS) under the electron impact ionization (EI) mode. The analytes were converted to their methyl esters by pyrolytic methylation in the hot GC injection port. The recoveries of alkylphosphonic acids were above 95% and the minimum detection limits were as low as 10 ng/mL. The recovery of the test chemicals was tested with solvents, dichloromethane, n-hexane, ethyl acetate, acetone, acetonitrile and methanol. The chemicals could be efficiently extracted by the hydrophilic solvents. The method did not work at the highly acidic pH (when acidified with dilute HCl) but worked well from pH 4.0 to 14.0. The present method was also tested with other tetra-(methyl, ethyl, propyl and n-butyl)ammonium hydroxides. The test chemicals were not converted to their methyl and ethyl esters with tetramethyl and tetraethylammonium hydroxides, whereas they were converted to their corresponding propyl and n-butyl esters with tetrapropyl and tetra(n-butyl)ammonium hydroxides. The method was also applied to two highly cross-linked polymeric sorbents DSC-6S and Oasis HLB. The recovery of the chemicals on these sorbents was observed to be poor. Methylation using phenyltrimethylammonium hydroxide is non-hazardous and advantageous over methylation using diazomethane. The method was applied to the analysis of aqueous samples given in one of the official proficiency tests conducted by the Organization for the Prohibition of Chemical Weapons and all the spiked chemicals were identified as methyl esters.

Degradation of cyanidin-3-rutinoside and formation of protocatechuic acid methyl ester in methanol solution by gamma irradiation.

PubMed

Lee, Seung Sik; Kim, Tae Hoon; Lee, Eun Mi; Lee, Min Hee; Lee, Ha Yeong; Chung, Byung Yeoup

2014-08-01

Anthocyanins are naturally occurring phenolic compounds having broad biological activities including anti-mutagenesis and anti-carcinogenesis. We studied the effects and the degradation mechanisms of the most common type of anthocyanins, cyanidin-3-rutinoside (cya-3-rut), by using gamma ray. Cya-3-rut in methanol (1mg/ml) was exposed to gamma-rays from 1 to 10kGy. We found that the reddish colour of cya-3-rut in methanol disappeared gradually in a dose-dependent manner and effectively disappeared (>97%) at 10kGy of gamma ray. Concomitantly, a new phenolic compound was generated and identified as a protocatechuic acid methyl ester by liquid chromatography, (1)H, and (13)C NMR. The formation of protocatechuic acid methyl ester increased with increasing irradiation and the amount of protocatechuic acid methyl ester formed by decomposition of cya-3-rut (20μg) at 10kGy of gamma ray was 1.95μg. In addition, the radical-scavenging activities were not affected by gamma irradiation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Solubility and diffusivity of N{sub 2}O and CO{sub 2} in (monoethanolamine + N-methyldiethanolamine + water) and in (monoethanolamine + 2-amino-2-methyl-1-propanol + water)

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

Li, M.H.; Lai, M.D.

1995-03-01

Solutions of amines are frequently used in gas-treating processes to remove acid gases, such as CO{sub 2} and H{sub 2}S, from gas streams in the natural gas and synthetic ammonia industries and petroleum chemical plants. The solubility and diffusivity of N{sub 2}O in (monoethanolamine + N-methyldiethanolamine + water) and in (monoethanolamine + 2-amino-2-methyl-l-propanol + water) were measured at 30, 35, and 40 C and at atmospheric pressure. Six (monoethanolamine + N-methyldiethanolamine + water) and five (monoethanolamine + 2-amino-2-methyl-l-propanol + water) systems were studied. The total amine mass percent in all cases was 30. The solubilities were measured by a solubilitymore » apparatus similar to that of Haimour and Sandall (1984). A wetted wall column absorber was used to obtain the diffusivity of N{sub 2}O in amines. The N{sub 2}O solubilities in amine solutions have been correlated on the basis of the excess Henry constant correlation of Wang et al. (1992). The N{sub 2}O analogy was used to estimate the solubility and diffusivity of CO{sub 2} in (monoethanolamine + N-methyldiethanolamine + water) and in (monoethanolamine + 2-amino-2-methyl-l-propanol + water).« less

'Benifuuki' green tea containing o-methylated catechin reduces symptoms of Japanese cedar pollinosis: a randomized, double-blind, placebo-controlled trial.

PubMed

Masuda, Sawako; Maeda-Yamamoto, Mari; Usui, Satoko; Fujisawa, Takao

2014-06-01

Methylated catechin, one of the active ingredients in green tea, has been reported to ameliorate allergic reactions. We evaluated the efficacy of 'Benifuuki' green tea, which contains O-methylated epigallocatechin-3-O-[3-O-methyl] gallate (O-methylated EGCG), in alleviating Japanese cedar pollinosis (JCP). The study was a double-blind, randomized, placebo-controlled trial. The subjects with JCP were randomly assigned to drink 700ml of 'Benifuuki' green tea containing O-methylated EGCG or 'Yabukita' green tea (not containing O-methylated EGCG) as a placebo every day from December 2007 through March 2008, which includes the pollen season. The primary outcome was the area under the curve (AUC) of symptom scores during the peak pollen season. Fifty-one adults with JCP participated in the study. Twenty-six subjects were assigned to 'Benifuuki' and 25 to 'Yabukita'. The AUC of symptom score during the peak pollen season in the 'Benifuuki' group was significantly smaller than in the 'Yabukita' group for each of runny nose, itchy eyes, tearing, total nasal symptom score, total ocular symptom score, nasal symptom-medication score and ocular symptom-medication score. The total QOL-related questionnaire score for one week in the peak pollen season was significantly better in the 'Benifuuki' group. Increase in the peripheral eosinophil count in response to pollen exposure was suppressed in the 'Benifuuki' group. No adverse events were reported in either group. 'Benifuuki' green tea containing a large amount of O-methylated EGCG reduced the symptoms of JCP and has potential as a complementary/alternative medicine for treating seasonal allergic rhinitis.

Two Players Make a Formidable Combination: In Situ Generated Poly(acrylic anhydride-2-methyl-acrylic acid-2-oxirane-ethyl ester-methyl methacrylate) Cross-Linking Gel Polymer Electrolyte toward 5 V High-Voltage Batteries.

PubMed

Ma, Yue; Ma, Jun; Chai, Jingchao; Liu, Zhihong; Ding, Guoliang; Xu, Gaojie; Liu, Haisheng; Chen, Bingbing; Zhou, Xinhong; Cui, Guanglei; Chen, Liquan

2017-11-29

Electrochemical performance of high-voltage lithium batteries with high energy density is limited because of the electrolyte instability and the electrode/electrolyte interfacial reactivity. Hence, a cross-linking polymer network of poly(acrylic anhydride-2-methyl-acrylic acid-2-oxirane-ethyl ester-methyl methacrylate) (PAMM)-based electrolyte was introduced via in situ polymerization inspired by "shuangjian hebi", which is a statement in a traditional Chinese Kungfu story similar to the synergetic effect of 1 + 1 > 2. A poly(acrylic anhydride) and poly(methyl methacrylate)-based system is very promising as electrolyte materials for lithium-ion batteries, in which the anhydride and acrylate groups can provide high voltage resistance and fast ionic conductivity, respectively. As a result, the cross-linking PAMM-based electrolyte possesses a significant comprehensive enhancement, including electrochemical stability window exceeding 5 V vs Li + /Li, an ionic conductivity of 6.79 × 10 -4 S cm -1 at room temperature, high mechanical strength (27.5 MPa), good flame resistance, and excellent interface compatibility with Li metal. It is also demonstrated that this gel polymer electrolyte suppresses the negative effect resulting from dissolution of Mn 2+ ions at 25 and 55 °C. Thus, the LiNi 0.5 Mn 1.5 O 4 /Li and LiNi 0.5 Mn 1.5 O 4 /Li 4 Ti 5 O 12 cells using the optimized in situ polymerized cross-linking PAMM-based gel polymer electrolyte deliver stable charging/discharging profiles and excellent rate performance at room temperature and even at 55 °C. These findings suggest that the cross-linking PAMM is an intriguing candidate for 5 V class high-voltage gel polymer electrolyte toward high-energy lithium-on batteries.

Soybean biodiesel methyl esters, free glycerin and acid number quantification by 1H nuclear magnetic resonance spectroscopy.

PubMed

Coral, Natasha; Rodrigues, Elizabeth; Rumjanek, Victor; Zamian, José Roberto; da Rocha Filho, Geraldo Narciso; da Costa, Carlos Emmerson Ferreira

2013-02-01

Production of alternative fuels, such as biodiesel, from transesterification of vegetable oil driven by heterogeneous catalysts is a promising alternative to fossil diesel. However, achieving a successful substitution for a new renewable fuel depends on several quality parameters. (1)H NMR spectroscopy was used to determine the amount of methyl esters, free glycerin and acid number in the transesterification of soybean oil with methanol in the presence of hydrotalcite-type catalyst to produce biodiesel. Reaction parameters, such as temperature and time, were used to evaluate soybean oil methyl esters rate conversion. Temperatures of 100 to 180 °C and times of 20 to 240 min were tested on a 1 : 12 molar ratio soybean oil/methanol reaction. At 180 °C/240 min conditions, a rate of 94.5 wt% of methyl esters was obtained, where free glycerin and free fatty acids were not detected. Copyright © 2012 John Wiley & Sons, Ltd.

Intergenerational impact of paternal lifetime exposures to both folic acid deficiency and supplementation on reproductive outcomes and imprinted gene methylation.

PubMed

Ly, Lundi; Chan, Donovan; Aarabi, Mahmoud; Landry, Mylène; Behan, Nathalie A; MacFarlane, Amanda J; Trasler, Jacquetta

2017-07-01

Do paternal exposures to folic acid deficient (FD), and/or folic acid supplemented (FS) diets, throughout germ cell development adversely affect male germ cells and consequently offspring health outcomes? Male mice exposed over their lifetimes to both FD and FS diets showed decreased sperm counts and altered imprinted gene methylation with evidence of transmission of adverse effects to the offspring, including increased postnatal-preweaning mortality and variability in imprinted gene methylation. There is increasing evidence that disruptions in male germ cell epigenetic reprogramming are associated with offspring abnormalities and intergenerational disease. The fetal period is the critical time of DNA methylation pattern acquisition for developing male germ cells and an adequate supply of methyl donors is required. In addition, DNA methylation patterns continue to be remodeled during postnatal spermatogenesis. Previous studies have shown that lifetime (prenatal and postnatal) folic acid deficiency can alter the sperm epigenome and increase the incidence of fetal morphological abnormalities. Female BALB/c mice (F0) were placed on one of four amino-acid defined diets for 4 weeks before pregnancy and throughout pregnancy and lactation: folic acid control (Ctrl; 2 mg/kg), 7-fold folic acid deficient (7FD; 0.3 mg/kg), 10-fold high FS (10FS, 20 mg/kg) or 20-fold high FS (20FS, 40 mg/kg) diets. F1 males were weaned to their respective prenatal diets to allow for diet exposure during all windows of germline epigenetic reprogramming: the erasure, re-establishment and maintenance phases. F0 females were mated with chow-fed males to produce F1 litters whose germ cells were exposed to the diets throughout embryonic development. F1 males were subsequently mated with chow-fed female mice. Two F2 litters, unexposed to the experimental diets, were generated from each F1 male; one litter was collected at embryonic day (E)18.5 and one delivered and followed postnatally. DNA

Lipoxygenase in Caragana jubata responds to low temperature, abscisic acid, methyl jasmonate and salicylic acid.

PubMed

Bhardwaj, Pardeep Kumar; Kaur, Jagdeep; Sobti, Ranbir Chander; Ahuja, Paramvir Singh; Kumar, Sanjay

2011-09-01

Lipoxygenase (LOX) catalyses oxygenation of free polyunsaturated fatty acids into oxylipins, and is a critical enzyme of the jasmonate signaling pathway. LOX has been shown to be associated with biotic and abiotic stress responses in diverse plant species, though limited data is available with respect to low temperature and the associated cues. Using rapid amplification of cDNA ends, a full-length cDNA (CjLOX) encoding lipoxygenase was cloned from apical buds of Caragana jubata, a temperate plant species that grows under extreme cold. The cDNA obtained was 2952bp long consisting of an open reading frame of 2610bp encoding 869 amino acids protein. Multiple alignment of the deduced amino acid sequence with those of other plants demonstrated putative LH2/ PLAT domain, lipoxygenase iron binding catalytic domain and lipoxygenase_2 signature sequences. CjLOX exhibited up- and down-regulation of gene expression pattern in response to low temperature (LT), abscisic acid (ABA), methyl jasmonate (MJ) and salicylic acid (SA). Among all the treatments, a strong up-regulation was observed in response to MJ. Data suggests an important role of jasmonate signaling pathway in response to LT in C. jubata. Copyright © 2011 Elsevier B.V. All rights reserved.

Structure-function properties of amylose-oleic acid inclusion complexes grafted with poly(methyl acrylate)

USDA-ARS?s Scientific Manuscript database

Spherulites, produced by steam jet-cooking high-amylose starch and oleic acid, were grafted with methyl acrylate, both before and after removal of un-complexed amylopectin. For comparison, granular high-amylose corn starch was graft polymerized in a similar manner. The amount of grafted and ungrafte...

Synthetic mucin fragments: synthesis of O-sulfo and O-methyl derivatives of allyl O-(beta-D-galactopyranosyl)-(1-->3)-2-acetamido-2-deoxy-alpha-D- galactopyranoside as potential compounds for sulfotransferases.

PubMed

Jain, R K; Piskorz, C F; Matta, K L

1995-10-02

Allyl 2-acetamido-4,6-O-(4-methoxybenzylidene)-2-deoxy-alpha-D-galact opy ranoside (1) was condensed with either 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl bromide (2) or 2,3,4-tri-O-benzoyl-6-O-bromoacetyl-alpha-D-galactopyranosyl bromide (14) in the presence of mercuric cyanide. Selective substitution with methyl, sulfo or both at desired positions, followed by the removal of protecting groups, afforded allyl O-(beta-D-galactopyranosyl)-(1-->3)-2-acetamido-2-deoxy-6-O-methyl-alpha -D- galactopyranoside (5), allyl O-(6-O-sulfo-beta-D-galactopyranosyl sodium salt)-(1-->3)-2-acetamido-2-deoxy-6- O-methyl-alpha-D-galactopyranoside (10), allyl O-(beta-D-galactopyranosyl)-(1-->3)-2-acetamido-2-deoxy-6-O-sulfo-alpha- D- galactopyranoside sodium salt (13), allyl O-(6-O-sulfo-beta-D-galactopyranosyl sodium salt)-(1-->3)-2-acetamido-2-deoxy- alpha-D-galactopyranoside (17) and allyl O-(3-O-sulfo-beta-D-galactopyranosyl sodium salt)-(1-->3)-2-acetamido-2-deoxy- alpha-D-galactopyranoside (22). The structures of compounds 5, 10, 13, 17 and 22 were established by 13C NMR and FAB mass spectroscopy.

Methyl and p-Bromobenzyl Esters of Hydrogenated Kaurenoic Acid for Controlling Anthracnose in Common Bean Plants.

PubMed

Mota, Suellen F; Oliveira, Denilson F; Heleno, Vladimir C G; Soares, Ana Carolina F; Midiwo, Jacob O; Souza, Elaine A

2017-03-01

Kaurenoic acid derivatives were prepared and submitted to in vitro assays with the fungus Colletotrichum lindemuthianum, which causes anthracnose disease in the common bean. The most active substances were found to be methyl and p-bromobenzylesters, 7 and 9, respectively, of the hydrogenated kaurenoic acid, which presented a minimum inhibitory concentration (MIC) of 0.097 and 0.131 mM, respectively, while the commercial fungicide methyl thiophanate (MT) presented a MIC of 0.143 mM. Substances 7 (1.401 mM) and 9 (1.886 mM) reduced the severity of anthracnose in common bean to values statistically comparable to MT (2.044 mM). According to an in silico study, both compounds 7 and 9 are inhibitors of the ketosteroid isomerase (KSI) enzyme produced by other organisms, the amino acid sequence of which could be detected in fungal genomes. These substances appeared to act against C. lindemuthianum by inhibiting its KSI. Therefore, substances 7 and 9 are promising for the development of new fungicides.

The 1-((diorganooxyphosphonyl)-methyl)-2,4- and -2,6-diamido benzenes

NASA Technical Reports Server (NTRS)

Mikroyannidis, John A. (Inventor); Kourtides, Demetrius A. (Inventor)

1989-01-01

1-((Diorgano oxyphosphonyl) methyl)-2,4- and -2,6-dinitro and diamino benzenes are prepared by nitrating an (organophosphonyl) methyl benzene to produce the dinitro compounds which are then reduced to the diamino compounds. The organo grounds (alkyl, haloalkyl, aryl) on the phosphorus may be removed to give the free acids (HO)2P(double bond O)single bond. The diamino compounds may be polymerized with dianhydrides or diacyl halides to produce fire and flame resistant polymers which are useful in the manufacture of aircraft structures.

Conformational free energies of methyl-α-L-iduronic and methyl-β-D-glucuronic acids in water

NASA Astrophysics Data System (ADS)

Babin, Volodymyr; Sagui, Celeste

2010-03-01

We present a simulation protocol that allows for efficient sampling of the degrees of freedom of a solute in explicit solvent. The protocol involves using a nonequilibrium umbrella sampling method, in this case, the recently developed adaptively biased molecular dynamics method, to compute an approximate free energy for the slow modes of the solute in explicit solvent. This approximate free energy is then used to set up a Hamiltonian replica exchange scheme that samples both from biased and unbiased distributions. The final accurate free energy is recovered via the weighted histogram analysis technique applied to all the replicas, and equilibrium properties of the solute are computed from the unbiased trajectory. We illustrate the approach by applying it to the study of the puckering landscapes of the methyl glycosides of α-L-iduronic acid and its C5 epimer β-D-glucuronic acid in water. Big savings in computational resources are gained in comparison to the standard parallel tempering method.

Conformational free energies of methyl-alpha-L-iduronic and methyl-beta-D-glucuronic acids in water.

PubMed

Babin, Volodymyr; Sagui, Celeste

2010-03-14

We present a simulation protocol that allows for efficient sampling of the degrees of freedom of a solute in explicit solvent. The protocol involves using a nonequilibrium umbrella sampling method, in this case, the recently developed adaptively biased molecular dynamics method, to compute an approximate free energy for the slow modes of the solute in explicit solvent. This approximate free energy is then used to set up a Hamiltonian replica exchange scheme that samples both from biased and unbiased distributions. The final accurate free energy is recovered via the weighted histogram analysis technique applied to all the replicas, and equilibrium properties of the solute are computed from the unbiased trajectory. We illustrate the approach by applying it to the study of the puckering landscapes of the methyl glycosides of alpha-L-iduronic acid and its C5 epimer beta-D-glucuronic acid in water. Big savings in computational resources are gained in comparison to the standard parallel tempering method.

Ras regulation of DNA-methylation and cancer

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

Patra, Samir Kumar

2008-04-01

Genome wide hypomethylation and regional hypermethylation of cancer cells and tissues remain a paradox, though it has received a convincing confirmation that epigenetic switching systems, including DNA-methylation represent a fundamental regulatory mechanism that has an impact on genome maintenance and gene transcription. Methylated cytosine residues of vertebrate DNA are transmitted by clonal inheritance through the strong preference of DNA methyltransferase, DNMT1, for hemimethylated-DNA. Maintenance of methylation patterns is necessary for normal development of mice, and aberrant methylation patterns are associated with many human tumours. DNMT1 interacts with many proteins during cell cycle progression, including PCNA, p53, EZH2 and HP1. Rasmore » family of GTPases promotes cell proliferation by its oncogenic nature, which transmits signals by multiple pathways in both lipid raft dependent and independent fashion. DNA-methylation-mediated repression of DNA-repair protein O6-methylguanine DNA methyltransferase (MGMT) gene and increased rate of K-Ras mutation at codon for amino acids 12 and 13 have been correlated with a secondary role for Ras-effector homologues (RASSFs) in tumourigenesis. Lines of evidence suggest that DNA-methylation associated repression of tumour suppressors and apoptotic genes and ceaseless proliferation of tumour cells are regulated in part by Ras-signaling. Control of Ras GTPase signaling might reduce the aberrant methylation and accordingly may reduce the risk of cancer development.« less

The origin and fate of 4-methyl steroid hydrocarbons. I. Diagenesis of 4-methyl sterenes

NASA Astrophysics Data System (ADS)

Wolff, George A.; Lamb, Neil A.; Maxwell, James R.

1986-03-01

Treatment of 4-methylcholest-4-ene under mild acid conditions at low temperatures gives chemical evidence for certain features seen in the distributions of sedimentary 4-methyl steroid hydrocarbons, and further indicates that many low temperature diagenetic reactions of steroids are explicable in terms of acid catalysed rearrangements. Specifically, the results provide: (i) Indirect evidence that the 4-ene skeleton is a key intermediate in the dehydration of 4-methyl stanols in sediments. (ii) An explanation for the distribution of 4-methyl sterenes and A-nor sterenes in the lacustrine Messel shale (Eocene). (iii) An explanation for the presence of 4β-methyl steranes in relatively immature sedimentary rocks, despite the precursor stanols having the 4α-methyl configuration. With increasing maturity in the Paris Basin shales (Lower Toarcian), the less stable 4β-methyl steranes decrease gradually in abundance relative to their 4α-methyl counterparts, at a rate fairly similar to the change in pristane stereochemistry.

Investigations into the chemistry, toxicology, metabolism and possible mode of action of O-ethyl S-methyl ethylphosphonothioate

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

Hur, J.H.

1989-01-01

The chemical and metabolic oxidation of O-ethyl S-methyl ethylphosphonthioate (1) as a model compound was studied. This compound has the following toxicological properties: LD{sub 50} (rat) 4.6 mg/kg, LD{sub 50}(HF) 14.0 ug/g; k{sub i}(BAChE) {equals} 303, k{sub i}(HFAChE) {equals} 623. {sup 13} C- and {sup 31}P-NMR were mainly used in this study. The chemical oxidation of 1 with m-CPBA in CDCl{sub 3} resulted in the formation of O-ethyl ethylphosphonic acid (2), O-ethyl ethylphosphinyloxymethylsulfonate (3) and O-ethyl ethylphosphonic acid anhydride (4). However, oxidation reaction of the model compound 1 with MPPA in D{sub 2}O gave 2 and methylsulfonic acid. 1 wasmore » incubated in vitro with rat liver microsomal oxidase, and 2 and methylsulfenic acid were observed along with 1. For the in vivo study, a number of houseflies were treated with 14ug/g (LD{sub 50} level) of 1. Analysis of the extracts of metabolic products provided evidence of the formation of 2. The existence of 1 S-oxide was demonstrated by use of a trapping method and the observation of oxidation products. The S-oxide has been proposed as a possible active intermediate responsible for the high toxicity of 1 to animals. However, owing to its instability it is unlikely that the S-oxide intermediate would persist in an aqueous biological environment long enough to attack the target enzyme. 4 was shown to have high toxicity to the rat and housefly and was also a potent anticholinesterase against BAChE and HFAChE . The presence of 4 was observed directly by the monitoring experiments during the chemical oxidation in aqueous conditions. This provided evidence that this metabolite is stable enough to attack the target site in biological systems. The anhydride 4 is proposed as the active metabolite in in vivo systems, responsible for high toxicity of 1.« less

Methyl 3-O-α-l-fucopyranosyl β-d-glucopyran­oside tetra­hydrate

PubMed Central

Eriksson, Lars; Widmalm, Göran

2012-01-01

The title compound, C13H24O10·4H2O, is the methyl glycoside of a disaccharide structural element present in the backbone of the capsular polysaccharide from Klebsiella K1, which contains only three sugars and a substituent in the polysaccharide repeating unit. The conformation of the title disaccharide is described by the glycosidic torsion angles ϕH = 51.1 (1)° and ψH = 25.8 (1)°. In the crystal, a number of O—H⋯O hydrogen bonds link the methyl glycoside and water mol­ecules, forming a three-dimensional network. One water mol­ecule is disordered over two positions with occupancies of 0.748 (4) and 0.252 (4). PMID:23284493

Orphenadrinium picrate picric acid.

PubMed

Fun, Hoong-Kun; Hemamalini, Madhukar; Siddaraju, B P; Yathirajan, H S; Narayana, B

2010-02-24

The asymmetric unit of the title compound N,N-dimethyl-2-[(2-methyl-phen-yl)phenyl-meth-oxy]ethanaminium picrate picric acid, C(18)H(24)NO(+)·C(6)H(2)N(3)O(7) (-)·C(6)H(3)N(3)O(7), contains one orphenadrinium cation, one picrate anion and one picric acid mol-ecule. In the orphenadrine cation, the two aromatic rings form a dihedral angle of 70.30 (7)°. There is an intra-molecular O-H⋯O hydrogen bond in the picric acid mol-ecule, which generates an S(6) ring motif. In the crystal structure, the orphenadrine cations, picrate anions and picric acid mol-ecules are connected by strong inter-molecular N-H⋯O hydrogen bonds, π⋯π inter-actions between the benzene rings of cations and anions [centroid-centroid distance = 3.5603 (9) Å] and weak C-H⋯O hydrogen bonds, forming a three-dimensional network.

Maternal intake of methyl-group donors affects DNA methylation of metabolic genes in infants.

PubMed

Pauwels, Sara; Ghosh, Manosij; Duca, Radu Corneliu; Bekaert, Bram; Freson, Kathleen; Huybrechts, Inge; Langie, Sabine A S; Koppen, Gudrun; Devlieger, Roland; Godderis, Lode

2017-01-01

Maternal nutrition during pregnancy and infant nutrition in the early postnatal period (lactation) are critically involved in the development and health of the newborn infant. The Maternal Nutrition and Offspring's Epigenome (MANOE) study was set up to assess the effect of maternal methyl-group donor intake (choline, betaine, folate, methionine) on infant DNA methylation. Maternal intake of dietary methyl-group donors was assessed using a food-frequency questionnaire (FFQ). Before and during pregnancy, we evaluated maternal methyl-group donor intake through diet and supplementation (folic acid) in relation to gene-specific ( IGF2 DMR, DNMT1 , LEP , RXRA ) buccal epithelial cell DNA methylation in 6 months old infants ( n  = 114) via pyrosequencing. In the early postnatal period, we determined the effect of maternal choline intake during lactation (in mothers who breast-fed for at least 3 months) on gene-specific buccal DNA methylation ( n  = 65). Maternal dietary and supplemental intake of methyl-group donors (folate, betaine, folic acid), only in the periconception period, was associated with buccal cell DNA methylation in genes related to growth ( IGF2 DMR), metabolism ( RXRA ), and appetite control ( LEP ). A negative association was found between maternal folate and folic acid intake before pregnancy and infant LEP (slope = -1.233, 95% CI -2.342; -0.125, p  = 0.0298) and IGF2 DMR methylation (slope = -0.706, 95% CI -1.242; -0.107, p  = 0.0101), respectively. Positive associations were observed for maternal betaine (slope = 0.875, 95% CI 0.118; 1.633, p  = 0.0241) and folate (slope = 0.685, 95% CI 0.245; 1.125, p  = 0.0027) intake before pregnancy and RXRA methylation. Buccal DNMT1 methylation in the infant was negatively associated with maternal methyl-group donor intake in the first and second trimester of pregnancy and negatively in the third trimester. We found no clear association between maternal choline intake

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

Code of Federal Regulations, 2014 CFR

2014-04-01

... from edible fats and oils. 172.225 Section 172.225 Food and Drugs FOOD AND DRUG ADMINISTRATION... acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in food, subject to the following prescribed conditions: (a) The...

Purification and preliminary characterization of (E)-3-(2,4-dioxo-6-methyl-5-pyrimidinyl)acrylic acid synthase, an enzyme involved in biosynthesis of the antitumor agent sparsomycin.

PubMed

Parry, R J; Hoyt, J C

1997-02-01

Sparsomycin is an antitumor antibiotic produced by Streptomyces sparsogenes. Biosynthetic experiments have previously demonstrated that one component of sparsomycin is derived from L-tryptophan via the intermediacy of (E)-3-(4-oxo-6-methyl-5-pyrimidinyl)acrylic acid and (E)-3-(2,4-dioxo-6-methyl-5-pyrimidinyl)acrylic acid. An enzyme which catalyzes the conversion of (E)-3-(4-oxo-6-methyl-5-pyrimidinyl)acrylic acid to (E)-3-(2,4-dioxo-6-methyl-5-pyrimidinyl)acrylic acid has been purified 740-fold to homogeneity from S. sparsogenes. The molecular mass of the native and denatured enzyme was 87 kDa, indicating that the native enzyme is monomeric. The enzyme required NAD+ for activity but lacked rigid substrate specificity, since analogs of both NAD+ and 3-(4-oxo-6-methyl-5-pyrimidinyl)acrylic acid could serve as substrates. The enzyme was very weakly inhibited by mycophenolic acid. Monovalent cations were required for activity, with potassium ions being the most effective. The enzyme exhibited sensitivity toward diethylpyrocarbonate and some thiol-directed reagents, and it was irreversibly inhibited by 6-chloropurine. The properties of the enzyme suggest it is mechanistically related to inosine-5'-monophosphate dehydrogenase.

Reaction of Methyl Fluoroformyl Peroxycarbonate (FC(O)OOC(O)OCH3) with Cl Atoms: Formation of Hydro-ChloroFluoro-Peroxides.

PubMed

Berasategui, Matias; Argüello, Gustavo A; Burgos Paci, Maxi A

2017-10-12

The products following Cl atom initiated reactions of FC(O)OOC(O)OCH 3 in 50-760 Torr of N 2 at 296 K were investigated using FTIR. Reaction of Cl atoms with methyl fluoroformyl peroxycarbonate proceeds mainly via attack at the methyl group, forming FC(O)OOC(O)OCH 2 • radicals. Further reaction of this kind of radical with Cl 2 forms three new compounds: FC(O)OOC(O)OCH 2 Cl, FC(O)OOC(O)OCHCl 2 , and FC(O)OOC(O)OCCl 3 , whose existence was characterized experimentally by FTIR spectroscopy assisted by ab initio calculations at the B3LYP/6-31++G(d,p) level. Relative rate techniques were used to measure k (Cl+FC(O)OOC(O)OCH3) = (4.0 ± 0.4) × 10 -14 cm 3 molecule -1 s -1 and k (Cl+FC(O)OOC(O)OCH2Cl) = (3.2 ± 0.3) × 10 -14 cm 3 molecule -1 s -1 . When the reaction is run in the presence of oxygen, the paths giving chlorinated peroxide formation are suppressed, and oxidation to (mainly) CO 2 and HCl takes place through highly oxidized intermediates with lifetimes long enough to be detected by FTIR spectroscopy.

Understanding the effect of locked nucleic acid and 2'-O-methyl modification on the hybridization thermodynamics of a miRNA-mRNA pair in the presence and absence of AfPiwi protein.

PubMed

Kumar, Santosh; Mapa, Koyeli; Maiti, Souvik

2014-03-18

miRNAs are some of the key epigenetic regulators of gene expression. They act through hybridization with their target mRNA and modulate the level of respective proteins via different mechanisms. Various cancer conditions are known to be associated with up- and downregulation of the oncogenic and tumor suppressor miRNAs, respectively. The levels of aberrantly expressed oncogenic miRNAs can be downregulated in different ways. Similarly, restoration of tumor suppressor miRNAs to their normal levels can be achieved using miRNA mimics. However, the use of miRNA mimics is limited by their reduced biostability and function. We have studied the hybridization thermodynamics of the miRNA 26a (11-mer, including the seed sequence) guide strand with the mRNA (11-mer) target strand in the absence and presence of AfPiwi protein. We have also inserted locked nucleic acids (LNAs) and 2'-O-methyl-modified nucleotides into the guide strand, in a walk-through manner, to assess their effect on the binding efficiency between guide and target RNA. Insertion of LNA and 2'-O-methyl-modified nucleotides into the guide strand helped to strengthen the binding affinity irrespective of the position of insertion. However, in the presence of AfPiwi protein, these modifications reduced the binding affinity to different extents depending on the position of insertion. Insertion of a modification leads to an increase in the enthalpic contribution with an increased unfavorable entropic contribution, which negatively compensates for the higher favorable enthalpy.

Chemical composition and antimicrobial activity of fatty acid methyl ester of Quercus leucotrichophora fruits.

PubMed

Sati, Ankita; Sati, Sushil Chandra; Sati, Nitin; Sati, O P

2017-03-01

Natural fats and dietary oils are chief source of fatty acids and are well known to have antimicrobial activities against various microbes. The chemical composition and antimicrobial activities of fatty acids from fruits of white Oak (Quercus leucotrichophora) are yet unexplored and therefore the present study for the first time determines the fatty acid composition, and the antibacterial and antifungal activities of fatty acid methyl esters (FAME) of the white Oak plant found along the Himalayan region of Uttarakhand, India. The GCMS analysis revealed the presence of higher amount of saturated fatty acids than unsaturated fatty acids. FAME extract of fruits of Q. leucotrichophora demonstrated better antibacterial activity against Gram-positive bacteria than the Gram-negative bacteria. The present studies clearly establish the potential of the fruits of Q. leucotrichophora for use in soap, cosmetics and pharmaceutical industries.

Endogenous 5-methylcytosine protects neighboring guanines from N7 and O6-methylation and O6-pyridyloxobutylation by the tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone.

PubMed

Ziegel, Rebecca; Shallop, Anthony; Upadhyaya, Pramod; Jones, Roger; Tretyakova, Natalia

2004-01-20

All CG dinucleotides along exons 5-8 of the p53 tumor suppressor gene contain endogenous 5-methylcytosine (MeC). These same sites (e.g., codons 157, 158, 245, 248, and 273) are mutational hot spots in smoking-induced lung cancer. Several groups used the UvrABC endonuclease incision assay to demonstrate that methylated CG dinucleotides of the p53 gene are the preferred binding sites for the diol epoxides of bay region polycyclic aromatic hydrocarbons (PAH). In contrast, effects of endogenous cytosine methylation on the distribution of DNA lesions induced by tobacco-specific nitrosamines, e.g., 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), have not been elucidated. In the work presented here, a stable isotope labeling HPLC-ESI-MS/MS approach was employed to analyze the reactivity of the N7 and O6 positions of guanines within hemimethylated and fully methylated CG dinucleotides toward NNK-derived methylating and pyridyloxobutylating species. 15N3-labeled guanine bases were placed within synthetic DNA sequences representing endogenously methylated p53 codons 154, 157, and 248, followed by treatment with acetylated precursors to NNK diazohydroxides. HPLC-ESI-MS/MS analysis was used to determine the relative yields of N7- and O6-guanine adducts at the 15N3-labeled position. In all cases, the presence of MeC inhibited the formation of N7-methylguanine, O6-methylguanine, and O6-pyridyloxobutylguanine at a neighboring G, with the greatest decrease observed in fully methylated dinucleotides and at guanines preceded by MeC. Furthermore, the O6-Me-dG/N7-Me-G molar ratios were decreased in the presence of the 5'-neighboring MeC, suggesting that the observed decline in O6-alkylguanine adduct yields is, at least partially, a result of an altered reactivity pattern in methylated CG dinucleotides. These results indicate that, unlike N2-guanine adducts of PAH diol epoxides, NNK-induced N7- and O6-alkylguanine adducts are not preferentially formed at the endogenously

Production of o-diphenols by immobilized mushroom tyrosinase.

PubMed

Marín-Zamora, María Elisa; Rojas-Melgarejo, Francisco; García-Cánovas, Francisco; García-Ruiz, Pedro Antonio

2009-01-15

The o-diphenols 4-tert-butyl-catechol, 4-methyl-catechol, 4-methoxy-catechol, 3,4-dihydroxyphenylpropionic acid and 3,4-dihydroxyphenylacetic acid were produced from the corresponding monophenols (4-tert-butyl-phenol, 4-methyl-phenol, 4-methoxy-phenol, p-hydroxyphenylpropionic acid and p-hydroxyphenylacetic acid) using immobilized mushroom tyrosinase from Agaricus bisporus. In all cases the yield was R(diphenol)> or =88-96%, which, according to the literature, is the highest yield so far, obtained using tyrosinase. The reaction was carried out in 0.5M borate buffer pH 9.0 which was used to minimize the diphenolase activity of tyrosinase by complexing the o-diphenols generated. Hydroxylamine and ascorbic acid were also present in the reaction medium, the former being used to reduce mettyrosinase to deoxytyrosinase, closing the catalytic cycle, and the latter to reduce the o-quinone produced to o-diphenol. Inactivation of the tyrosinase by ascorbic acid was also minimized due to the formation of an ascorbic acid-borate complex. Concentrations of the o-diphenolic compounds obtained at several reaction times were determined by gas chromatography-mass spectrometry (GC-MS) and UV-vis spectroscopy. The experimental results are discussed.

Synthesis and physicochemical properties of the furan dicarboxylic acid, 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid, an inhibitor of plasma protein binding in uraemia.

PubMed

Costigan, M G; Gilchrist, T L; Lindup, W E

1996-06-01

The furan dicarboxylic acid, 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (5-propyl FPA) accumulates in the plasma of patients with chronic renal failure and is a major contributor to the drug binding defect of uraemic plasma. This acid has also been implicated in several other aspects of the uraemic syndrome: anaemia, irregularities of thyroid function, neurological symptoms and inhibition of active tubular secretion. The acid is not commercially available and its synthesis, starting with Meldrum's acid and methyl succinyl chloride, is described. The pKa values were measured by titration and values of 3.2 and 3.6 respectively were assigned to the carboxylic acid groups attached directly to the ring at position 3 and at position 2 (on the side-chain). The partition coefficient (log P) between hydrochloric acid and octanol was 1.2 and the distribution coefficient (log D; octanol-phosphate buffer pH 7.4) was -0.59. The pKa values and the degree of hydrophobic character of 5-propyl FPA are consistent with those of other protein-bound acids which undergo active tubular secretion by the kidney and this substance may serve as an endogenous marker for the effects of drugs and disease on this process.

Different expressions and DNA methylation patterns of lysophosphatidic acid receptor genes in mouse tumor cells.

PubMed

Okabe, Kyoko; Hayashi, Mai; Wakabayashi, Naoko; Yamawaki, Yasuna; Teranishi, Miki; Fukushima, Nobuyuki; Tsujiuchi, Toshifumi

2010-01-01

Lysophosphatidic acid (LPA) receptors act as several biological effectors through LPA, which is a bioactive phospholipid. Recently, aberrant expressions of LPA receptor genes due to DNA methylation have been detected in several tumor cells. In this study, we measured expression levels and DNA methylation status of LPA receptor genes in mouse tumor cells, LL/2 lung carcinoma, B16F0 melanoma, FM3A mammary carcinoma and L1210 leukemia cells, compared with normal tissues. Total RNAs were extracted and RT-PCR analysis was performed. For DNA methylation status, bisulfite sequencing analysis was carried out, comparing outcomes with other tumor cells and normal tissues. The expressions of LPA1 gene were shown in LL/2, but not in B16F0, FM3A and L1210 cells. While the LPA2 gene was expressed in all 4 tumor cells, the LPA3 gene was unexpressed in them. The LPA1 and LPA3 unexpressed cells were highly methylated, although normal tissues were all unmethylated. The DNA methylation status was correlated with gene expression levels in cancer cells. The present results demonstrate that DNA methylation patterns of LPA receptor genes are dependent on cancer cell types, suggesting that LPA receptors may be new molecular targets for therapeutic approaches and chemoprevention. Copyright © 2011 S. Karger AG, Basel.

Esterification and transesterification of greases to fatty acid methyl esters with highly active diphanylammonium salts

USDA-ARS?s Scientific Manuscript database

We have conducted an investigation designed to identify alternate catalysts for the production of fatty acid methyl esters (FAME) to be used as biodiesel. Diphenylammonium sulfate (DPAS) and diphenylammonium chloride (DPA-HCl) salts were found to be highly active homogeneous catalysts for the simu...

High-throughput and site-specific identification of 2'-O-methylation sites using ribose oxidation sequencing (RibOxi-seq).

PubMed

Zhu, Yinzhou; Pirnie, Stephan P; Carmichael, Gordon G

2017-08-01

Ribose methylation (2'- O -methylation, 2'- O Me) occurs at high frequencies in rRNAs and other small RNAs and is carried out using a shared mechanism across eukaryotes and archaea. As RNA modifications are important for ribosome maturation, and alterations in these modifications are associated with cellular defects and diseases, it is important to characterize the landscape of 2'- O -methylation. Here we report the development of a highly sensitive and accurate method for ribose methylation detection using next-generation sequencing. A key feature of this method is the generation of RNA fragments with random 3'-ends, followed by periodate oxidation of all molecules terminating in 2',3'-OH groups. This allows only RNAs harboring 2'-OMe groups at their 3'-ends to be sequenced. Although currently requiring microgram amounts of starting material, this method is robust for the analysis of rRNAs even at low sequencing depth. © 2017 Zhu et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Catalytic performance of strong acid catalyst: Methyl modified SBA-15 loaded perfluorinated sulfonic acid obtained by the waste perfluorinated sulfonic acid ion exchange membrane

NASA Astrophysics Data System (ADS)

Jiang, Tingshun; Huang, Qiuyan; Li, Yingying; Fang, Minglan; Zhao, Qian

2018-02-01

Mesoporous molecular sieve (SBA-15) was modified using the trimethylchlorosilane as functional agent and the silylation SBA-15 mesoporous material was prepared in this work. The alcohol solution of perfluorinated sulfonic acid dissolved from the waste perfluorinated sulfonic acid ion exchange membrane (PFSIEM) was loaded onto the resulting mesoporous material by the impregnation method and their physicochemical properties were characterized by FT-IR, N2-physisorption, XRD, TG-DSC and TEM. The catalytic activities of these synthesized solid acid catalysts were evaluated by alkylation of phenol with tert-butyl alcohol. The influence of reaction temperature, weight hour space velocity (WHSV) and reaction time on the phenol conversion and product selectivity were assessed by means of a series of experiments. The results showed that with the increase of the active component of the catalyst, these catalysts still remained good mesoporous structure, but the mesoporous ordering decreased to some extent. These catalysts exhibited good catalytic performance for the alkylation of phenol with tert-butanol. The maximum phenol conversion of 89.3% with 70.9% selectivity to 4-t-butyl phenol (4-TBP) was achieved at 120 °C and the WHSV is 4 h-1. The methyl group was loaded on the surface of the catalyst by trimethylchlorosilane. This is beneficial to retard the deactivation of the catalyst. In this work, the alkylation of phenol with tert-butyl alcohol were carried out using the methyl modified SBA-15 mesoporous materials loaded perfluorinated sulfonic acid as catalysts. The results show that the resulting catalyst exhibited high catalytic activity.

The effect of ingested lactulose on absorption of L-rhamnose, D-xylose, and 3-O-methyl-D-glucose in subjects with ileostomies.

PubMed

Jenkins, A P; Menzies, I S; Nukajam, W S; Creamer, B

1994-09-01

We have previously shown that small oral doses of poorly absorbed solute can significantly reduce absorption of test sugars in normal volunteers. To confirm these results and investigate the underlying mechanism, the effects of lactulose on absorption of three test sugars in subjects with ileostomies were studied. Ten fasted subjects with ileostomies ingested an isosmolar test solution containing 2.5 g 3-O-methyl-D-glucose, 5.0 g D-xylose, 1.0 g L-rhamnose, and 50 microCi 51Cr-labelled ethylenediaminetetraacetic acid together with a blue dye transit marker. Urine was collected for time periods of 0-5 h and 5-24 h, to measure excretion of absorbed sugars, and ileostomy effluent was saved from 0-5 h and from 5 h until blue dye transit marker was no longer present, to measure small-bowel output of unabsorbed sugars. After 1 week the test was repeated, including 5 g lactulose in the test solution. Inclusion of lactulose in the test solution significantly reduced the 5 h and 24 h urine excretion of L-rhamnose and D-xylose but not that of 3-O-methyl-D-glucose and increased 0- to 5-h and total ileostomy output of L-rhamnose and D-xylose but not of 3-O-methyl-D-glucose. The presence of lactulose also reduced the time for first appearance of the blue dye transit marker in the effluent and increased effluent volume together with output of electrolyte. Poorly absorbed solute reduces intestinal absorption by retention of fluid and electrolyte, with subsequent intraluminal dilution and acceleration of transit.

Further investigation of the biosynthesis of caffeine in tea plants (Camellia sinensis L.). Methylation of transfer ribonucleic acid by tea leaf extracts.

PubMed Central

Suzuki, T; Takahashi, E

1976-01-01

1. The tRNA methyltransferase activity in vitro of leaves, cotyledons and roots of 85-day-old tea seedlings was studied. 2. The activity of extracts prepared from tea leaves with Polycar AT (insoluble polyvinylpyrrolidine) had optimum pH7.7 and was greatly influenced by thiol compounds, but only slightly by metal ions and ammonium acetate. 3. The activities of extracts, expressed per mg of protein, were as follows: roots greater than leaves greater than cotyledons. The only methylated base isolated after incubation with these preparations was 1-methyladenine. 4. The results did not support the view of involvement of methylation of nucleic acids in caffeine biosynthesis in tea plants. In contrast, it is suggested that theophylline is synthesized from the specific methylated precursor in nucleic acids, namely 1-methyladenylic acid, via 1-methylxanthine. PMID:12749

Branched-chain dicationic ionic liquids for fatty acid methyl ester assessment by gas chromatography.

PubMed

Talebi, Mohsen; Patil, Rahul A; Sidisky, Leonard M; Berthod, Alain; Armstrong, Daniel W

2017-12-06

Twelve bis- or dicationic ionic liquids (ILs) including eight based on imidazolium, a single one based on phosphonium, and three based on pyrrolidinium cationic units were prepared with the bis(trifluoromethyl sulfonyl) imide anion. The two identical cationic moieties were attached by different alkyl spacers having three or five carbons and differing alkyl substituents attached to the spacer. The SLB-IL111 column, as the most polar commercial stationary phase known, was included in the study for comparison. Isothermal separations of a rapeseed oil fatty acid methyl ester (FAME) sample were used to study and compare the 12 IL-based column performances and selectivities. The retention times of the most retained methyl esters of lignoceric (C24:0) and erucic (C22:1) acids were used to estimate the IL polarity. The phosphonium dicationic IL column was, by far, the least polar. Imidazolium-based dicationic IL columns were the most polar. Polarity and selectivity for the FAME separation were somewhat related. The separation of a 37-FAME standard mixture allowed the investigation of selectivity variations observed on the 12 IL-based columns under temperature gradients up to 230 °C. The remarkable selectivity of the IL-based columns is demonstrated by the detailed analysis of the cis/trans C18:1 isomers of a partially hydrogenated vegetable oil sample on 30-m columns, separations competing with that done following an "official method" performed on a 100-m column. Graphical abstract Separation of fatty acid methyl esters on a 30-m 3m 2 C 5 (mpy) 2 . 2NTf 2 branched-chain dicationic IL-based column. Branched chain dicationic ILs show great selectivity for separation of cis/trans, ω-3/ω-6, and detailed analysis of cis/trans fats.

Altered Levels of Zinc and N-methyl-D-aspartic Acid Receptor Underlying Multiple Organ Dysfunctions After Severe Trauma

PubMed Central

Wang, Guanghuan; Yu, Xiaojun; Wang, Dian; Xu, Xiaohu; Chen, Guang; Jiang, Xuewu

2015-01-01

Background Severe trauma can cause secondary multiple organ dysfunction syndrome (MODS) and death. Oxidative stress and/or excitatory neurotoxicity are considered as the final common pathway in nerve cell injuries. Zinc is the cofactor of the redox enzyme, and the effect of the excitatory neurotoxicity is related to N-methyl-D-aspartic acid receptor (NMDAR). Material/Methods We investigated the levels of zinc and brainstem NMDAR in a rabbit model of severe trauma. Zinc and serum biochemical profiles were determined. Immunohistochemistry was used to detect brainstem N-methyl-D-aspartic acid receptor 1 (NR1), N-methyl-D-aspartic acid receptor 2A (NR2A), and N-methyl-D-aspartic acid receptor 2B (NR2B) expression. Results Brain and brainstem Zn levels increased at 12 h, but serum Zn decreased dramatically after the trauma. NR1 in the brainstem dorsal regions increased at 6 h after injury and then decreased. NR2A in the dorsal regions decreased to a plateau at 12 h after trauma. The levels of NR2B were lowest in the death group in the brainstem. Serum zinc was positively correlated with NR2A and 2B and negatively correlated with zinc in the brain. Correlations were also found between the brainstem NR2A and that of the dorsal brainstem, as well as between brainstem NR2A and changes in NR2B. There was a negative correlation between zinc and NR2A. Conclusions Severe trauma led to an acute reduction of zinc enhancing oxidative stress and the changes of NMDAR causing the neurotoxicity of the nerve cells. This may be a mechanism for the occurrence of MODS or death after trauma. PMID:26335029

Protective role of humic acids against picloram-induced genomic instability and DNA methylation in Phaseolus vulgaris.

PubMed

Taspinar, Mahmut Sinan; Aydin, Murat; Sigmaz, Burcu; Yildirim, Nalan; Agar, Guleray

2017-10-01

Picloram (4-amino-3,5,6-trichloropicolinic acid) is a liquid auxinic herbicide used to control broad-leaved weeds. Picloram is representing a possible hazard to ecosystems and human health. Therefore, in this study, DNA methylation changes and DNA damage levels in Phaseolus vulgaris exposed to picloram, as well as whether humic acid (HA) has preventive effects on these changes were investigated. Random amplified polymorphic DNA (RAPD) techniques were used for identification of DNA damage and coupled restriction enzyme digestion-random amplification (CRED-RA) techniques were used to detect the changed pattern of DNA methylation. According to the obtained results, picloram (5, 10, 20, and 40 mg/l) caused DNA damage profile changes (RAPDs) increasing, DNA hypomethylation and genomic template stability (GTS) decreasing. On the other hand, different concentrations of applied HA (2, 4, 6, 8, and 10%) reduced hazardous effects of picloram. The results of the experiment have explicitly indicated that HAs could be an alternative for reducing genetic damage in plants. In addition to the alleviate effects of humic acid on genetic damage, its epigenetic effect is hypomethylation.

Effects of maternal folic acid supplementation on gene methylation and being small for gestational age.

PubMed

Qian, Y-Y; Huang, X-L; Liang, H; Zhang, Z-F; Xu, J-H; Chen, J-P; Yuan, W; He, L; Wang, L; Miao, M-H; Du, J; Li, D-K

2016-10-01

Being small for gestational age (SGA), a foetal growth abnormality, has a long-lasting impact on childhood health. Its aetiology and underlying mechanisms are not well understood. Underlying epigenetic changes of imprinted genes have emerged as a potential pathological pathway because they may be associated with growth, including SGA. As a common methyl donor, folic acid (FA) is essential for DNA methylation, synthesis and repair, and FA supplementation is widely recommended for women planning pregnancy. The present study aimed to investigate the inter-relationships among methylation levels of two imprinted genes [H19 differentially methylated regions (DMRs) and MEST DMRs], maternal FA supplementation and SGA. We conducted a case-control study. Umbilical cord blood was taken from 39 SGA infants and 49 controls whose birth weights are appropriate for gestational age (AGA). DNA methylation levels of H19 and MEST DMRs were determined by an analysis of mass array quantitative methylation. Statistically significantly higher methylation levels were observed at sites 7.8, 9 and 17.18 of H19 (P = 0.030, 0.016 and 0.050, respectively) in the SGA infants compared to the AGA group. In addition, the association was stronger in male births where the mothers took FA around conception at six H19 sites (P = 0.004, 0.005, 0.048, 0.002, 0.021 and 0.005, respectively). Methylation levels at H19 DMRs were higher in SGA infants compared to AGA controls. It appears that the association may be influenced by maternal peri-conception FA supplementation and also be sex-specific. © 2016 The British Dietetic Association Ltd.

Beyond fatty acid methyl esters: Expanding the renewable carbon profile with alkenones from Isochrysis sp.

USDA-ARS?s Scientific Manuscript database

In addition to characteristic fatty acid methyl esters (FAMEs), biodiesel produced from Isochrysis sp. contains a significant amount (14% dry weight) of predominantly C37 and C38 longchain alkenones. These compounds are members of a class of lipids known collectively as polyunsaturated long-chain al...

40 CFR 721.304 - Acetic acid, [(5-chloro-8-quinolinyl)oxy-], 1-methyl hexyl ester.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.304 Acetic acid, [(5-chloro-8-quinolinyl)oxy-], 1-methyl hexyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The...

Properties of amylose-oleic acid inclusion complexes from corn starch grafted with poly(methyl acrylate)

USDA-ARS?s Scientific Manuscript database

Corn starch granules have been previously investigated as fillers in polymers. In this study, much smaller particles in the form of spherulites produced by steam jet-cooking high-amylose corn starch and oleic acid to form amylose inclusion complexes were graft polymerized with methyl acrylate, both ...

Innate immune restriction and antagonism of viral RNA lacking 2'-O methylation

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

Hyde, Jennifer L.; Diamond, Michael S., E-mail: diamond@borcim.wustl.edu; Molecular Microbiology, Washington University School of Medicine, St Louis., MO 63110

N-7 and 2′-O methylation of host cell mRNA occurs in the nucleus and results in the generation of cap structures (cap 0, m{sup 7}GpppN; cap 1, m{sup 7}GpppNm) that control gene expression by modulating nuclear export, splicing, turnover, and protein synthesis. Remarkably, RNA cap modification also contributes to mammalian cell host defense as viral RNA lacking 2′-O methylation is sensed and inhibited by IFIT1, an interferon (IFN) stimulated gene (ISG). Accordingly, pathogenic viruses that replicate in the cytoplasm have evolved mechanisms to circumvent IFIT1 restriction and facilitate infection of mammalian cells. These include: (a) generating cap 1 structures on theirmore » RNA through cap-snatching or virally-encoded 2′-O methyltransferases, (b) using cap-independent means of translation, or (c) using RNA secondary structural motifs to antagonize IFIT1 binding. This review will discuss new insights as to how specific modifications at the 5′-end of viral RNA modulate host pathogen recognition responses to promote infection and disease.« less

Spectrophotometric study of the copigmentation of malvidin 3-O-glucoside with p-coumaric, vanillic and syringic acids.

PubMed

Malaj, Naim; De Simone, Bruna Clara; Quartarolo, Angelo Domenico; Russo, Nino

2013-12-15

Anthocyanins are a natural source of pigments in plants and their processed food products have become attractive and excellent candidates to replace the synthetic colourants due to their characteristic intense colours and associated health benefits. The intermolecular copigmentation between anthocyanins and other colourless compounds has been reported to be an important way to enhance and stabilise the colour intensity of aqueous solutions. In the present work we report the equilibrium constant, stoichiometric ratio and the thermodynamic parameters (ΔG°, ΔH° and ΔS°) related to the intermolecular copigmentation reactions of the anthocyanin malvidin 3-O-glucoside with one hydroxycinnamic acid (p-coumaric acid) and two O-methylated hydroxybenzoic acids (vanillic and syringic acid). Different factors which affect their interactions such as copigment concentration, pH and temperature of the medium are examined at two pH levels (pH=2.50 and 3.65) corresponding to those of the major food mediums where these reactions take place (fruit juices, wine, jams etc.). Copyright © 2013 Elsevier Ltd. All rights reserved.

Optical resolution by preferential crystallization of (RS)-2-benzoylamino-2-benzyl-3-hydroxypropanoic acid and its use in synthesizing optically active 2-amino-2-methyl-3-phenylpropanoic acid.

PubMed

Shiraiwa, Tadashi; Suzuki, Masahiro; Sakai, Yoshio; Nagasawa, Hisashi; Takatani, Kazuhiro; Noshi, Daisuke; Yamanashi, Kenji

2002-10-01

To synthesize optically active 2-amino-2-methyl-3-phenylpropanoic acid (1), (RS)-2-benzoylamino-2-benzyl-3-hydroxypropanoic acid [(RS)-2] was first optically resolved using cinchonidine as a resolving agent to yield optically pure (S)- and (R)-2 in yields of about 70%, based on half of the starting amount of (RS)-2. Next, the racemic structure of (RS)-2 was examined based on melting point, solubility, IR spectrum, and binary and ternary phase diagrams, with the aim of optical resolution by preferential crystallization of (RS)-2. Results indicated that the (RS)-2 exists as a conglomerate at room temperature, although it forms a racemic compound at the melting point. The optical resolution by preferential crystallization yielded (S)- and (R)-2 with optical purities of about 90%, which were fully purified by recrystallization. After O-tosylation of (S)- and (R)-2, reduction by zinc powder and sodium iodide gave (R)- and (S)-1, respectively.

Adsorption Isotherm Studies of Methyl Bromide on MgO

NASA Astrophysics Data System (ADS)

Burns, Teresa; Larese, John

2004-03-01

The adsorption of methyl bromine onto highly-uniform magnesium oxide powder was studied. Methyl bromide was condensed onto the MgO substrate at temperatures between 164 K and 179 K. The layering behavior of the gas molecules was studied by a series of vapor pressure isotherms, using a high-accuracy, computer-controller system. The isotherms clearly show first layer formation at all temperatures, with second layer formation at higher temperatures; the 2D compressibility and isosteric heat of adsorption were determined. TEB sponsored by the Department of Energy EPSCOR Grant No. DE-FG02-01ER45895. JZL sponsored by start-up funds from the University of Tennessee - Knoxville and by the Division of Materials Sciences, Office of Basic Energy Sciences, U.S. Department of Energy, under contract No. DE-AC05-00OR22725 with Oak Ridge National Laboratory, managed and operated by UT-Battelle, LLC.

40 CFR 180.409 - Pirimiphos-methyl; tolerances for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Pirimiphos-methyl; tolerances for... § 180.409 Pirimiphos-methyl; tolerances for residues. (a) General. Tolerances are established for residues of the insecticide pirimiphos-methyl (O-(2-diethylamino-6-methyl-4-pyrimidinyl) O,O-dimethyl...

Simultaneous determination of salicylic, 3-methyl salicylic, 4-methyl salicylic, acetylsalicylic and benzoic acids in fruit, vegetables and derived beverages by SPME-LC-UV/DAD.

PubMed

Aresta, Antonella; Zambonin, Carlo

2016-03-20

Salicylic and benzoic acid are phenolic acids occurring in plant cells, thus they can be present in fruit and vegetables at various levels. They possess anti-inflammatory and antimicrobial properties, however they may induce symptoms and health problems in a small percentage of the population. Therefore, a low phenolic acid diet may be of clinical benefit to such individuals. In order to achieve this goal, the concentration of these substances in different food and beverages should be assessed. The present work describes for the first time a new method, based on solid phase microextraction (polydimethylsiloxane-divinylbenzene fiber) coupled to liquid chromatography with UV diode array detection, for the simultaneous determination of salicylic acid, 3-methyl salicylic acid, 4-methyl salicylic acid, acetylsalicylic acid and benzoic acid in selected fruit, vegetables and beverages. All the aspects influencing fiber adsorption (time, temperature, pH, salt addition) and desorption (desorption and injection time, desorption solvent mixture composition) of the analytes have been investigated. An isocratic separation was performed using an acetonitrile-phosphate buffer (pH 2.8; 2 mM) mixture (70:30, v/v) as the mobile phase. The estimated LOD and LOQ values (μg/mL) were in the range 0.002-0.028 and 0.007-0.095. The within-day and day-to-day precision values (RSD%) were between 4.7-6.1 and 6.6-9.4, respectively. The method has been successfully applied to the analysis of fava beans, blueberries, kiwi, tangerines, lemons, oranges and fruit juice (lemon and blueberry) samples. The major advantage of the method is that it only requires simple homogenization and/or centrifugation and dilution steps prior to SPME and injection in the LC system. Copyright © 2016 Elsevier B.V. All rights reserved.

Production of Fatty Acid Methyl Esters via the In Situ Transesterification of Soybean Oil in Carbon Dioxide-Expanded Methanol

USDA-ARS?s Scientific Manuscript database

The production of fatty acid methyl esters (FAME) by direct alkali- and acid-catalyzed in situ transesterification of soybean flakes in CO2-expanded methanol was examined at various temperatures and pressures. Attempts to synthesize FAME from soy flakes via alkaline catalysis, using sodium methoxid...

Synthesis of fatty acid methyl ester from crude jatropha (Jatropha curcas Linnaeus) oil using aluminium oxide modified Mg-Zn heterogeneous catalyst.

PubMed

Olutoye, M A; Hameed, B H

2011-06-01

The synthesis of fatty acid methyl esters (FAME) as a substitute to petroleum diesel was investigated in this study from crude jatropha oil (CJO), a non-edible, low-cost alternative feedstock, using aluminium modified heterogeneous basic oxide (Mg-Zn) catalyst. The transesterification reaction with methanol to methyl esters yielded 94% in 6h with methanol-oil ratio of 11:1, catalyst loading of 8.68 wt.% at 182°C and the properties of CJO fuel produced were determine and found to be comparable to the standards according to ASTM. In the range of experimental parameters investigated, it showed that the catalyst is selective to production of methyl esters from oil with high free fatty acid (FFA) and water content of 7.23% and 3.28%, respectively in a single stage process. Thus, jatropha oil is a promising feedstock for methyl ester production and large scale cultivation will help to reduce the product cost. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of methyl jasmonate, salicylic acid, Headline and Stadium on sucrose yield and storage properties

USDA-ARS?s Scientific Manuscript database

Methyl jasmonate (MeJA) and salicylic acid (SA) have been reported to enhance yield and protect crop plants and products against abiotic stresses and diseases. The effect of these compounds on sugarbeets, however, is unknown. Research was conducted in 2015 and 2016 to investigate the effects of an e...

Effect of methyl jasmonate, salicylic acid, Headline and Stadium on sucrose yield and storage properties

USDA-ARS?s Scientific Manuscript database

Methyl jasmonate (MeJA) and salicylic acid (SA) have been reported to enhance yield and protect crop plants and products against abiotic stresses and diseases. The effect of these compounds on sugarbeets, however, is unknown. Research was initiated in 2014 to investigate the effects of an early seas...

Bioassay-guided Isolation of Neuroprotective Fatty Acids from Nigella sativa against 1-methyl-4-phenylpyridinium-induced Neurotoxicity

PubMed Central

Hosseinzadeh, Leila; Monaghash, Hoda; Ahmadi, Farahnaz; Ghiasvand, Nastaran; Shokoohinia, Yalda

2017-01-01

Objective: Parkinson's disease, a slowly progressive neurological disease, is associated with degeneration of the basal ganglia of the brain and a deficiency of the neurotransmitter dopamine. The main aspects of researches are the protection of normal neurons against degeneration. Fatty acids (FAs), the key structural elements of dietary lipids, are carboxylic straight chains and notable parameters in nutritional and industrial usefulness of a plant. Materials and Methods: Black cumin, a popular anti-inflammatory and antioxidant food seasoning, contains nonpolar constituents such as FAs which were extracted using hexane. Different fractions and subfractions were apt to cytoprotection against apoptosis and inflammation induced by 1-methyl-4-phenylpyridinium (MPP+) in rat pheochromocytoma cell line (PC12) as a neural cell death model. The experiment consisted of examination of cell viability assessment, mitochondrial membrane potential (MMP), caspase-3 and -9 activity, and measurement of cyclooxygenase (COX) activity. Results: MPP+ induced neurotoxicity in PC12 cells. Pretreatment with subfractions containing FA mixtures attenuated MPP+-mediated apoptosis partially dependent on the inhibition of caspase-3 and -9 activity and increasing the MMP. A mixture of linoleic acid, oleic acid, and palmitic acid also decreased the COX activity induced by MPP+ in PC12 cells. Conclusion: Our observation indicated that subtoxic concentration of FA from Nigella sativa may exert cytoprotective effects through their anti-apoptotic and anti-inflammation actions and could be regarded as a dietary supplement. SUMMARY MPP+ induced neurotoxicity in PC12 cellsNigella sativa contains bioactive fatty acidsPretreatment with fatty acids attenuated MPP+ mediated apoptosis through inhibition of caspase 3 and 9 activityA mixture of linoleic acid, oleic acid, and palmitic acid decreased the COX activity induced by MPP+ in PC12 cellsDue to cytoprotective, anti apoptotic and anti inflammation

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 [Santa Fe, NM; Martinez, Rodolfo A [Santa Fe, NM; Unkefer, Clifford J [Los Alamos, NM

2008-01-22

The present invention is directed to labeled compounds of the formulae ##STR00001## wherein Q is selected from the group consisting of --S--, --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. The present invention is also directed to a process of preparing labeled compounds, e.g., process of preparing [.sup.13C]methacrylic acid by reacting a (CH.sub.3CH.sub.2O--.sup.13C(O)--.sup.13CH.sub.2)-- aryl sulfone precursor with .sup.13CHI to form a (CH.sub.3CH.sub.2O--.sup.13C(O)--.sup.13C(.sup.13CH.sub.3).sub.2)-- aryl sulfone intermediate, and, reacting the (CH.sub.3CH.sub.2O--.sup.13C(O)--.sup.13C(.sup.13CH.sub.3).sub.2)-- aryl sulfone intermediate with sodium hydroxide, followed by acid to form [.sup.13C]methacrylic acid. The present invention is further directed to a process of preparing [.sup.2H.sub.8]methyl methacrylate by reacting a (HOOC--C(C.sup.2H.sub.3).sub.2-- aryl sulfinyl intermediate with CD.sub.3I to form a (.sup.2H.sub.3COOC--C(C.sup.2H.sub.3).sub.2)-- aryl sulfinyl intermediate, and heating the(.sup.2H.sub.3COOC--C(C.sup.2H.sub.3).sub.2)-- aryl sulfinyl intermediate at temperatures and for time sufficient to form [.sup.2H.sub.8]methyl methacrylate.

Archaeal fibrillarin-Nop5 heterodimer 2'-O-methylates RNA independently of the C/D guide RNP particle.

PubMed

Tomkuvienė, Miglė; Ličytė, Janina; Olendraitė, Ingrida; Liutkevičiūtė, Zita; Clouet-d'Orval, Béatrice; Klimašauskas, Saulius

2017-09-01

Archaeal fibrillarin (aFib) is a well-characterized S -adenosyl methionine (SAM)-dependent RNA 2'- O -methyltransferase that is known to act in a large C/D ribonucleoprotein (RNP) complex together with Nop5 and L7Ae proteins and a box C/D guide RNA. In the reaction, the guide RNA serves to direct the methylation reaction to a specific site in tRNA or rRNA by sequence complementarity. Here we show that a Pyrococcus abyssi aFib-Nop5 heterodimer can alone perform SAM-dependent 2'- O -methylation of 16S and 23S ribosomal RNAs in vitro independently of L7Ae and C/D guide RNAs. Using tritium-labeling, mass spectrometry, and reverse transcription analysis, we identified three in vitro 2'- O -methylated positions in the 16S rRNA of P. abyssi , positions lying outside of previously reported pyrococcal C/D RNP methylation sites. This newly discovered stand-alone activity of aFib-Nop5 may provide an example of an ancestral activity retained in enzymes that were recruited to larger complexes during evolution. © 2017 Tomkuvienė et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Separation of the fatty acids in menhaden oil as methyl esters with a highly polar ionic liquid gas chromatographic column and identification by time of flight mass spectrometry.

PubMed

Fardin-Kia, Ali Reza; Delmonte, Pierluigi; Kramer, John K G; Jahreis, Gerhard; Kuhnt, Katrin; Santercole, Viviana; Rader, Jeanne I

2013-12-01

The fatty acids contained in marine oils or products are traditionally analyzed by gas chromatography using capillary columns coated with polyethylene glycol phases. Recent reports indicate that 100 % cyanopropyl siloxane phases should also be used when the analyzed samples contain trans fatty acids. We investigated the separation of the fatty acid methyl esters prepared from menhaden oil using the more polar SLB-IL111 (200 m × 0.25 mm) ionic liquid capillary column and the chromatographic conditions previously optimized for the separation of the complex mixture of fatty acid methyl esters prepared from milk fat. Identifications of fatty acids were achieved by applying Ag(+)-HPLC fractionation and GC-TOF/MS analysis in CI(+) mode with isobutane as the ionization reagent. Calculation of equivalent chain lengths confirmed the assignment of double bond positions. This methodology allowed the identification of 125 fatty acids in menhaden oil, including isoprenoid and furanoid fatty acids, and the novel 7-methyl-6-hexadecenoic and 7-methyl-6-octadecenoic fatty acids. The chromatographic conditions applied in this study showed the potential of separating in a single 90-min analysis, among others, the short chain and trans fatty acids contained in dairy products, and the polyunsaturated fatty acids contained in marine products.

Palladium(II) complexes with R(2)edda derived ligands. Part IV. O,O'-dialkyl esters of (S,S)-ethylenediamine-N,N'-di-2-(4-methyl)-pentanoic acid dihydrochloride and their palladium(II) complexes: synthesis, characterization and in vitro antitumoral activity against chronic lymphocytic leukemia (CLL) cells.

PubMed

Vujić, Jelena M; Cvijović, Milica; Kaluderović, Goran N; Milovanović, Marija; Zmejkovski, Bojana B; Volarević, Vladislav; Arsenijević, Nebojsa; Sabo, Tibor J; Trifunović, Srećko R

2010-09-01

Four novel bidentate N,N'-ligand precursors, including O,O'-dialkyl esters (alkyl = ethyl, n-propyl, n-butyl and n-pentyl), L1 x 2 HCl-L4 x 2 HCl, of (S,S)-ethylenediamine-N,N'-di-2-(4-methyl)-pentanoic acid dihydrochloride [(S,S)-H(4)eddl]Cl(2) and the corresponding palladium(II) complexes 1-4, were prepared and characterized by IR, (1)H NMR and (13)C NMR spectroscopy and elemental analysis. In vitro cytotoxicity of all compounds was determined against chronic lymphocytic leukemia cells (CLL). The compounds were found to exhibit higher antitumoral activity than cisplatin. The most active compound 2, [PdCl(2){(S,S)-nPr(2)eddl}], was found to be 13.6 times more active than cisplatin on CLL cells. 2010 Elsevier Masson SAS. All rights reserved.

Selective Methylation: an Incorrect Hypothesis

PubMed Central

Shugart, Lee

1976-01-01

“Selective methylation,” a hypothesis proposed to explain the discrepancy found in the degree of methyl deficiency of transfer ribonucleic acid, cannot be explained on the basis of some biological phenomenon. PMID:770445

Plasmon-resonance-enhanced visible-light photocatalytic activity of Ag quantum dots/TiO2 microspheres for methyl orange degradation

NASA Astrophysics Data System (ADS)

Yu, Xin; Shang, Liwei; Wang, Dongjun; An, Li; Li, Zhonghua; Liu, Jiawen; Shen, Jun

2018-06-01

We successfully prepared Ag quantum dots modified TiO2 microspheres by facile solvothermal and calcination method. The as-prepared Ag quantum dots/TiO2 microspheres were characterized by scanning electron microscope, transmission electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy and UV-vis diffuse reflectance spectroscopy. The Ag quantum dots/TiO2 photocatalyst showed excellent visible light absorption and efficient photocatalytic activity for methyl orange degradation. And the sample with the molar ratio of 0.05 (Ag to Ti) showed the best visible light photocatalytic activity for methyl orange degradation, mainly because of the surface plasmon resonance (SPR) effects of Ag quantum dots to generate electron and hole pairs for enhanced visible light photocatalysis. Finally, possible visible light photocatalytic mechanism of Ag quantum dots/TiO2 microspheres for methyl orange degradation was proposed in detail.

Adsorption Isotherm Studies of Methyl Bromide on MgO

NASA Astrophysics Data System (ADS)

Harper, Tj; Burns, Te; Larese, Jz

2003-03-01

This research involves the adsorption of methyl bromine and methane onto highly-uniform magnesium oxide powder. Methyl bromide was condensed onto the MgO substrate at temperatures between 175 K and 179 K. The layering behavior of the gas molecules was studied by a series of vapor pressure isotherms, using a high-accuracy, computer-controlled system. The isotherms clearly show first layer formation at all temperatures, followed by a continuous layer growth to saturation. Isotherms will be presented and future work discussed. TJH and TEB research sponsored by the Department of Energy EPSCOR Grant No. DE-FG02-01ER45895. JZL research sponsored by start-up funds from the University of Tennessee - Knoxville and by the Division of Materials Sciences, Office of Basic Energy Sciences, U.S. Department of Energy, under contract No. DE-AC05-00OR22725 with Oak Ridge National Laboratory, managed and operated by UT-Battelle, LLC.

4-Hydroxy-3-methyl-6-phenylbenzofuran-2-carboxylic acid ethyl ester derivatives as potent anti-tumor agents.

PubMed

Hayakawa, Ichiro; Shioya, Rieko; Agatsuma, Toshinori; Furukawa, Hidehiko; Naruto, Shunji; Sugano, Yuichi

2004-01-19

Based on the structure of 4-hydroxy-3-methyl-6-phenylbenzofuran-2-carboxylic acid ethyl ester (1), which exhibits selective cytotoxicity against a tumorigenic cell line, (2,4-dimethoxyphenyl)-(4-hydroxy-3-methyl-6-phenylbenzofuran-2-yl)-methanone (18m) was designed and synthesized as a biologically stable derivative containing no ester group. Although the potency of 18m was almost the same as our initial hit compound 1, 18m is expected to last longer in the human body as an anticancer agent.

Activity of influenza C virus O-acetylesterase with O-acetyl-containing compounds.

PubMed Central

Garcia-Sastre, A; Villar, E; Manuguerra, J C; Hannoun, C; Cabezas, J A

1991-01-01

Influenza C virus (strain C/Johannesburg/1/66) was grown, harvested, purified and used as source for the enzyme O-acetylesterase (N-acyl-O-acetylneuraminate O-acetylhydrolase; EC 3.1.1.53). This activity was studied and characterized with regard to some new substrates. The pH optimum of the enzyme is around 7.6, its stability at different pH values shows a result similar to that of the pH optimum, and its activity is well maintained in the pH range from 7.0 to 8.5 (all these tests were performed with 4-nitrophenyl acetate as substrate). Remarkable differences were found in the values of both Km and Vmax, with the synthetic substrates 4-nitrophenyl acetate, 2-nitrophenyl acetate, 4-methylumbelliferyl acetate, 1-naphthyl acetate and fluorescein diacetate. The use of 4-nitrophenyl acetate, 4-methylumbelliferyl acetate or 1-naphthyl acetate as substrate seems to be convenient for routine work, but it is better to carry out the measurements in parallel with those on bovine submandibular gland mucin (the latter is a natural and commercially available substrate). It was found that 4-acetoxybenzoic acid, as well as the methyl ester of 2-acetoxybenzoic acid, but not 2-acetoxybenzoic acid itself, are cleaved by this enzyme. Triacetin, di-O-acetyladenosine, tri-O-acetyladenosine, and di-O-acetyl-N-acetyladenosine phosphate, hitherto unreported as substrates for this viral esterase, are hydrolysed at different rates by this enzyme. We conclude that the O-acetylesterase from influenza C virus has a broad specificity towards both synthetic and natural non-sialic acid-containing substrates. Zn2+, Mn2+ and Pb2+ (as their chloride salts), N-acetylneuraminic acid, 4-methyl-umbelliferone and 2-acetoxybenzoic acid (acetylsalicylic acid) did not act as inhibitors. Images Fig. 1. PMID:1991039

Rapid Photodegradation of Methyl Orange (MO) Assisted with Cu(II) and Tartaric Acid

PubMed Central

Guo, Jing; Chen, Xue; Shi, Ying; Lan, Yeqing; Qin, Chao

2015-01-01

Cu(II) and organic carboxylic acids, existing extensively in soil and aquatic environments, can form complexes that may play an important role in the photodegradation of organic contaminants. In this paper, the catalytic role of Cu(II) in the removal of methyl orange (MO) in the presence of tartaric acid with light was investigated through batch experiments. The results demonstrate that the introduction of Cu(II) could markedly enhance the photodegradation of MO. In addition, high initial concentrations of Cu(II) and tartaric acid benefited the decomposition of MO. The most rapid removal of MO assisted by Cu(II) was achieved at pH 3. The formation of Cu(II)-tartaric acid complexes was assumed to be the key factor, generating hydroxyl radicals (•OH) and other oxidizing free radicals under irradiation through a ligand-to-metal charge-transfer pathway that was responsible for the efficient degradation of MO. Some intermediates in the reaction system were also detected to support this reaction mechanism. PMID:26241043

EXTRACTION OF TETRAVALENT PLUTONIUM VALUES WITH METHYL ETHYL KETONE, METHYL ISOBUTYL KETONE ACETOPHENONE OR MENTHONE

DOEpatents

Seaborg, G.T.

1961-08-01

A process is described for extracting tetravalent plutonium from an aqueous acid solution with methyl ethyl ketone, methyl isobutyl ketone, or acetophenone and with the extraction of either tetravalent or hexavalent plutonium into menthone. (AEC)

An improved synthesis for the (Z)-14-methyl-9-pentadecenoic acid and its topoisomerase I inhibitory activity

PubMed Central

Carballeira, Néstor M.; Sanabria, David; Oyola, Delise

2006-01-01

An improved synthesis for the (Z)-14-methyl-9-pentadecenoic acid was developed based on the appropriate use of (trimethylsilyl)acetylene as the key reagent in the synthesis. The reported synthesis started with commercially available 8-bromo-1-octanol and furnished the desired acid in seven steps and in a 16% overall yield, a significant improvement over the previous reported synthesis for this fatty acid. The synthesis reported herein afforded sufficient amounts to study the acid topoisomerase I inhibitory potential and it was found that the title acid inhibits the human placenta DNA topoisomerase I enzyme at concentrations of 500 μM. PMID:17680032

Seed storage protein deficiency improves sulfur amino acid content in common bean (Phaseolus vulgaris L.): redirection of sulfur from gamma-glutamyl-S-methyl-cysteine.

PubMed

Taylor, Meghan; Chapman, Ralph; Beyaert, Ronald; Hernández-Sebastià, Cinta; Marsolais, Frédéric

2008-07-23

The contents of sulfur amino acids in seeds of common bean ( Phaseolus vulgaris L.) are suboptimal for nutrition. They accumulate large amounts of a gamma-glutamyl dipeptide of S-methyl-cysteine, a nonprotein amino acid that cannot substitute for methionine or cysteine in the diet. Protein accumulation and amino acid composition were characterized in three genetically related lines integrating a progressive deficiency in major seed storage proteins, phaseolin, phytohemagglutinin, and arcelin. Nitrogen, carbon, and sulfur contents were comparable among the three lines. The contents of S-methyl-cysteine and gamma-glutamyl-S-methyl-cysteine were progressively reduced in the mutants. Sulfur was shifted predominantly to the protein cysteine pool, while total methionine was only slightly elevated. Methionine and cystine contents (mg per g protein) were increased by up to ca. 40%, to levels slightly above FAO guidelines on amino acid requirements for human nutrition. These findings may be useful to improve the nutritional quality of common bean.

Orphenadrinium picrate picric acid

PubMed Central

Fun, Hoong-Kun; Hemamalini, Madhukar; Siddaraju, B. P.; Yathirajan, H. S.; Narayana, B.

2010-01-01

The asymmetric unit of the title compound N,N-dimethyl-2-[(2-methyl­phen­yl)phenyl­meth­oxy]ethanaminium picrate picric acid, C18H24NO+·C6H2N3O7 −·C6H3N3O7, contains one orphenadrinium cation, one picrate anion and one picric acid mol­ecule. In the orphenadrine cation, the two aromatic rings form a dihedral angle of 70.30 (7)°. There is an intra­molecular O—H⋯O hydrogen bond in the picric acid mol­ecule, which generates an S(6) ring motif. In the crystal structure, the orphenadrine cations, picrate anions and picric acid mol­ecules are connected by strong inter­molecular N—H⋯O hydrogen bonds, π⋯π inter­actions between the benzene rings of cations and anions [centroid–centroid distance = 3.5603 (9) Å] and weak C—H⋯O hydrogen bonds, forming a three-dimensional network. PMID:21580426

Semi-Preparative Separation of 10 Caffeoylquinic Acid Derivatives Using High Speed Counter-Current Chromatogaphy Combined with Semi-Preparative HPLC from the Roots of Burdock (Arctium lappa L.).

PubMed

Zheng, Zhenjia; Wang, Xiao; Liu, Pengli; Li, Meng; Dong, Hongjing; Qiao, Xuguang

2018-02-15

Burdock roots are healthy dietary supplements and a kind of famous traditional Chinese medicine, which contains large amounts of caffeoylquinic acid derivatives. However, little research has been reported on the preparative separation of these compounds from burdock roots. In the present study, a combinative method of HSCCC and semi-preparative HPLC was developed for the semi-preparative separation of caffeoylquinic acid derivatives from the burdock roots. The ethyl acetate extract of burdock roots was first fractionated by MCI macroporous resin chromatography and give three fractions (Fr. 1-3) from the elution of 40% methanol. Then, these three fractions (120 mg) were separately subjected to HSCCC for purification with the solvent system composed of petroleum ether-ethyl acetate-methanol-water at different volume ratios, and the mixtures were further purified by semi-preparative HPLC. As a result, a total of eight known caffeoylquinic acid derivatives including 3- O -caffeoylquinic acid (32.7 mg, 95.7%), 1,5- O - dicaffeoylquinic acid (4.3 mg, 97.2%), 3- O -caffeoylquinic acid methyl ester (12.1 mg, 93.2%), 1,3- O -dicaffeoylquinic acid (42.9 mg, 91.1%), 1,5- O -dicaffeoyl-3- O -(4-maloyl)-quinic acid (4.3 mg, 84.5%), 4,5- O -dicaffeoylquinic acid (5.3 mg, 95.5%), 1,5- O -dicaffeoyl-3- O -succinylquinic acid (8.7 mg, 93.4%), and 1,5- O -dicaffeoyl-4- O -succinylquinic acid (1.7 mg, 91.8%), and two new compounds were obtained. The new compounds were 1,4- O -dicaffeoyl-3-succinyl methyl ester quinic acid (14.6 mg, 96.1%) and 1,5- O -dicaffeoyl-3- O -succinyl methyl ester quinic acid (3.1 mg, 92.6%), respectively. The research indicated that the combination of HSCCC and semi-preparative HPLC is a highly efficient approach for preparative separation of the instability and bioactive caffeoylquinic acid derivatives from natural products.

Continuous hydrogenation of ethyl levulinate to γ-valerolactone and 2-methyl tetrahydrofuran over alumina doped Cu/SiO2 catalyst: the potential of commercialization

NASA Astrophysics Data System (ADS)

Zheng, Junlin; Zhu, Junhua; Xu, Xuan; Wang, Wanmin; Li, Jiwen; Zhao, Yan; Tang, Kangjian; Song, Qi; Qi, Xiaolan; Kong, Dejin; Tang, Yi

2016-07-01

Hydrogenation of levulinic acid (LA) and its esters to produce γ-valerolactone (GVL) and 2-methyl tetrahydrofuran (2-MTHF) is a key step for the utilization of cellulose derived LA. Aiming to develop a commercially feasible base metal catalyst for the production of GVL from LA, with satisfactory activity, selectivity, and stability, Al2O3 doped Cu/SiO2 and Cu/SiO2 catalysts were fabricated by co-precipitation routes in parallel. The diverse physio-chemical properties of these two catalysts were characterized by XRD, TEM, dissociative N2O chemisorptions, and Py-IR methods. The catalytic properties of these two catalysts were systematically assessed in the continuous hydrogenation of ethyl levulinate (EL) in a fixed-bed reactor. The effect of acidic property of the SiO2 substrate on the catalytic properties was investigated. To justify the potential of its commercialization, significant attention was paid on the initial activity, proper operation window, by-products control, selectivity, and stability of the catalyst. The effect of reaction conditions, such as temperature and pressure, on the performance of the catalyst was also thoroughly studied. The development of alumina doped Cu/SiO2 catalyst strengthened the value-chain from cellulose to industrially important chemicals via LA and GVL.

Continuous hydrogenation of ethyl levulinate to γ-valerolactone and 2-methyl tetrahydrofuran over alumina doped Cu/SiO2 catalyst: the potential of commercialization

PubMed Central

Zheng, Junlin; Zhu, Junhua; Xu, Xuan; Wang, Wanmin; Li, Jiwen; Zhao, Yan; Tang, Kangjian; Song, Qi; Qi, Xiaolan; Kong, Dejin; Tang, Yi

2016-01-01

Hydrogenation of levulinic acid (LA) and its esters to produce γ-valerolactone (GVL) and 2-methyl tetrahydrofuran (2-MTHF) is a key step for the utilization of cellulose derived LA. Aiming to develop a commercially feasible base metal catalyst for the production of GVL from LA, with satisfactory activity, selectivity, and stability, Al2O3 doped Cu/SiO2 and Cu/SiO2 catalysts were fabricated by co-precipitation routes in parallel. The diverse physio-chemical properties of these two catalysts were characterized by XRD, TEM, dissociative N2O chemisorptions, and Py-IR methods. The catalytic properties of these two catalysts were systematically assessed in the continuous hydrogenation of ethyl levulinate (EL) in a fixed-bed reactor. The effect of acidic property of the SiO2 substrate on the catalytic properties was investigated. To justify the potential of its commercialization, significant attention was paid on the initial activity, proper operation window, by-products control, selectivity, and stability of the catalyst. The effect of reaction conditions, such as temperature and pressure, on the performance of the catalyst was also thoroughly studied. The development of alumina doped Cu/SiO2 catalyst strengthened the value-chain from cellulose to industrially important chemicals via LA and GVL. PMID:27377401

Desulfurization of 4-methyl dibenzothiophene using titanium supported Keggin type polyoxometalate

NASA Astrophysics Data System (ADS)

Lesbani, Aldes; Anggraini, Ana; Mohadi, Risfidian; Rohendi, Dedi; Said, Muhammad

2017-03-01

Titanium supported Keggin type polyoxometalate H5PV2Mo10O40.nH2O has been prepared using tetra isopropyl orthotitanate by sol-gel method and microemulsion to form H5PV2Mo10O40/TiO2. Compound H5PV2Mo10O40.nH2O/TiO2 was characterized using FTTR spectroscopy, X-Ray analysis, and acidity measurement. FTTR spectrum showed that all vibration of titanium and polyoxometalate were appeared in H5PV2Mo10O40.nH2O/TiO2 with decreasing crystallinity. The acidity of H5PV2Mo10O40.nH2O/TiO2 was higher than H5PV2Mo10O40.nH2O. Desulfurization of 4-methyl dibenzothiophene (4-MDBT) using H5PV2Mo10O40.nH2O/TiO2 as catalyst resulted conversion of 4-MDBT was 99% and higher than desulfurization using H5PV2Mo10O40.nH2O under mild conditions.

NiFe(C2O4)x as a heterogeneous Fenton catalyst for removal of methyl orange.

PubMed

Liu, Yucan; Zhang, Guangming; Chong, Shan; Zhang, Nan; Chang, Huazhen; Huang, Ting; Fang, Shunyan

2017-05-01

This paper studies a heterogeneous Fenton catalyst NiFe(C 2 O 4 ) x , which showed better catalytic activity than Ni(C 2 O 4 ) x and better re-usability than Fe(C 2 O 4 ) x . The methyl orange removal efficiency was 98% in heterogeneous Fenton system using NiFe(C 2 O 4 ) x . The prepared NiFe(C 2 O 4 ) x had a laminated shape and the size was in the range of 2-4 μm, and Ni was doped into catalyst's structure successfully. The NiFe(C 2 O 4 ) x had a synergistic effect of catalyst of 24.7 for methyl orange removal, and the dope of Ni significantly reduced the leaching of Fe by 77%. The reaction factors and kinetics were investigated. Under the optimal conditions, 0.4 g/L of catalyst dose and 10 mmol/L of hydrogen peroxide concentration, 98% of methyl orange was removed within 20 min. Analysis showed that hydroxyl radicals and superoxide radicals participated in the reaction. With NiFe(C 2 O 4 ) x catalyst, the suitable pH range for heterogeneous Fenton system was wide from 3 to 10. The catalyst showed good efficiency after five times re-use. NiFe(C 2 O 4 ) x provided great potential in treatment of refractory wastewater with excellent property. Copyright © 2017 Elsevier Ltd. All rights reserved.

Use of MIDI-fatty acid methyl ester analysis to monitor the transmission of Campylobacter during commercial poultry processing.

PubMed

Hinton, Arthur; Cason, J A; Hume, Michael E; Ingram, Kimberly D

2004-08-01

The presence of Campylobacter spp. on broiler carcasses and in scald water taken from a commercial poultry processing facility was monitored on a monthly basis from January through June. Campylobacter agar, Blaser, was used to enumerate Campylobacter in water samples from a multiple-tank scalder; on prescalded, picked, eviscerated, and chilled carcasses; and on processed carcasses stored at 4 degrees C for 7 or 14 days. The MIDI Sherlock microbial identification system was used to identify Campylobacter-like isolates based on the fatty acid methyl ester profile of the bacteria. The dendrogram program of the Sherlock microbial identification system was used to compare the fatty acid methyl ester profiles of the bacteria and determine the degree of relatedness between the isolates. Findings indicated that no Campylobacter were recovered from carcasses or scald tank water samples collected in January or February, but the pathogen was recovered from samples collected in March, April, May, and June. Processing generally produced a significant (P < 0.05) decrease in the number of Campylobacter recovered from broiler carcasses, and the number of Campylobacter recovered from refrigerated carcasses generally decreased during storage. Significantly (P < 0.05) fewer Campylobacter were recovered from the final tank of the multiple-tank scald system than from the first tank. MIDI similarity index values ranged from 0.104 to 0.928 based on MIDI-fatty acid methyl ester analysis of Campylobacterjejuni and Campylobacter coli isolates. Dendrograms of the fatty acid methyl ester profile of the isolates indicated that poultry flocks may introduce several strains of C. jejuni and C. coli into processing plants. Different populations of the pathogen may be carried into the processing plant by successive broiler flocks, and the same Campylobacter strain may be recovered from different poultry processing operations. However, Campylobacter apparently is unable to colonize equipment in the

Methyl Ester Production via Heterogeneous Acid-Catalyzed Simultaneous Transesterification and Esterification Reactions

NASA Astrophysics Data System (ADS)

Indrayanah, S.; Erwin; Marsih, I. N.; Suprapto; Murwani, I. K.

2017-05-01

The heterogeneous acid catalysts (MgF2 and ZnF2) have been used to catalyze the simultaneous transesterification and esterification reactions of crude palm oil (CPO) with methanol. Catalysts were synthesized by sol-gel method (combination of fluorolysis and hydrolysis). The physicochemical, structural, textural, thermal stability of the prepared catalysts was investigated by N2 adsorption-desorption, XRD, FT-IR, SEM and TG/DTG. Both MgF2 and ZnF2 have rutile structures with a different phase. The surface area of ZnF2 is smaller than that of MgF2, but the pore size and volume of ZnF2 are larger than those of MgF2. However, these materials are thermally stable. The performance of the catalysts is determined from the yield of catalysts toward the formation of methyl ester determined based on the product of methyl ester obtained from the reaction. The catalytic activity of ZnF2 is higher than MgF2 amounted to 85.21% and 26.82% with the optimum condition. The high activity of ZnF2 could be attributed to its pore diameter and pore volume but was not correlated with its surface area. The yield of methyl ester decreased along with the increase in molar ratio of methanol/CPO from 85.21 to 80.99 for ZnF2, respectively.

21 CFR 173.385 - Sodium methyl sulfate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium methyl sulfate. 173.385 Section 173.385... CONSUMPTION Specific Usage Additives § 173.385 Sodium methyl sulfate. Sodium methyl sulfate may be present in... pectin by sulfuric acid and methyl alcohol and subsequent treatment with sodium bicarbonate. (b) It does...

DHA-rich n-3 fatty acid supplementation decreases DNA methylation in blood leukocytes: the OmegAD study.

PubMed

Karimi, Mohsen; Vedin, Inger; Freund Levi, Yvonne; Basun, Hans; Faxén Irving, Gerd; Eriksdotter, Maria; Wahlund, Lars-Olof; Schultzberg, Marianne; Hjorth, Erik; Cederholm, Tommy; Palmblad, Jan

2017-10-01

Background: Dietary fish oils, rich in long-chain n-3 (ω-3) fatty acids (FAs) [e.g., docosahexaenoic acid (DHA, 22:6n-3) and eicosapentaenoic acid (EPA, 20:5n-3)], modulate inflammatory reactions through various mechanisms, including gene expression, which is measured as messenger RNA concentration. However, the effects of long-term treatment of humans with DHA and EPA on various epigenetic factors-such as DNA methylation, which controls messenger RNA generation-are poorly described. Objective: We wanted to determine the effects of 6 mo of dietary supplementation with an n-3 FA preparation rich in DHA on global DNA methylation of peripheral blood leukocytes (PBLs) and the relation to plasma EPA and DHA concentrations in Alzheimer disease (AD) patients. Design: In the present study, DNA methylation in four 5'-cytosine-phosphate-guanine-3' (CpG) sites of long interspersed nuclear element-1 repetitive sequences was assessed in a group of 63 patients (30 given the n-3 FA preparation and 33 given placebo) as an estimation of the global DNA methylation in blood cells. Patients originated from the randomized, double-blind, placebo-controlled OmegAD study, in which 174 AD patients received either 1.7 g DHA and 0.6 g EPA (the n-3 FA group) or placebo daily for 6 mo. Results: At 6 mo, the n-3 FA group displayed marked increases in DHA and EPA plasma concentrations (2.6- and 3.5-fold), as well as decreased methylation in 2 out of 4 CpG sites ( P < 0.05 for all), respectively. This hypomethylation in CpG2 and CpG4 sites showed a reverse correlation to changes in plasma EPA concentration ( r = -0.25, P = 0.045; and r = -0.26, P = 0.041, respectively), but not to changes in plasma DHA concentration, and were not related to apolipoprotein E-4 allele frequency. Conclusion: Supplementation with n-3 FA for 6 mo was associated with global DNA hypomethylation in PBLs. Our data may be of importance in measuring various effects of marine oils, including gene expression, in patients

27 CFR 21.117 - Methyl isobutyl ketone.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Methyl isobutyl ketone. 21.117 Section 21.117 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU....117 Methyl isobutyl ketone. (a) Acidity (as acetic acid). 0.02 percent by weight, maximum. (b) Color...

27 CFR 21.117 - Methyl isobutyl ketone.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Methyl isobutyl ketone. 21.117 Section 21.117 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU....117 Methyl isobutyl ketone. (a) Acidity (as acetic acid). 0.02 percent by weight, maximum. (b) Color...

N.m.r. studies of the conformation of analogues of methyl beta-lactoside in methyl sulfoxide-d6.

PubMed

Rivera-Sagredo, A; Jiménez-Barbero, J; Martín-Lomas, M

1991-12-16

The 1H- and 13C-n.m.r. spectra of solutions of methyl beta-lactoside (1), all of its monodeoxy derivatives (2, 3, 6-10), the 3-O-methyl derivative (4), and methyl 4-O-beta-D-galactopyranosyl-D-xylopyranoside (5) in methyl sulfoxide-d6 have been analysed. The n.O.e.'s and specific desheildings indicate similar distributions of low-energy conformers, comparable to those in aqueous solution. The major conformer has torsion angles phi H and psi H of 49 degrees and 5 degrees, respectively, with contributions of conformers with phi/psi 24 degrees/-59 degrees, 22 degrees/32 degrees, and 6 degrees/44 degrees.

Jasmonic acid/methyl jasmonate accumulate in wounded soybean hypocotyls and modulate wound gene expression.

PubMed

Creelman, R A; Tierney, M L; Mullet, J E

1992-06-01

Jasmonic acid (JA) and its methyl ester, methyl jasmonate (MeJA), are plant lipid derivatives that resemble mammalian eicosanoids in structure and biosynthesis. These compounds are proposed to play a role in plant wound and pathogen responses. Here we report the quantitative determination of JA/MeJA in planta by a procedure based on the use of [13C,2H3]MeJA as an internal standard. Wounded soybean (Glycine max [L] Merr. cv. Williams) stems rapidly accumulated MeJA and JA. Addition of MeJA to soybean suspension cultures also increased mRNA levels for three wound-responsive genes (chalcone synthase, vegetative storage protein, and proline-rich cell wall protein) suggesting a role for MeJA/JA in the mediation of several changes in gene expression associated with the plants' response to wounding.

Monitoring a simple hydrolysis process in an organic solid by observing methyl group rotation.

PubMed

Beckmann, Peter A; Bohen, Joseph M; Ford, Jamie; Malachowski, William P; Mallory, Clelia W; Mallory, Frank B; McGhie, Andrew R; Rheingold, Arnold L; Sloan, Gilbert J; Szewczyk, Steven T; Wang, Xianlong; Wheeler, Kraig A

2017-09-01

We report a variety of experiments and calculations and their interpretations regarding methyl group (CH 3 ) rotation in samples of pure 3-methylglutaric anhydride (1), pure 3-methylglutaric acid (2), and samples where the anhydride is slowly absorbing water from the air and converting to the acid [C 6 H 8 O 3 (1) + H 2 O → C 6 H 10 O 4 (2)]. The techniques are solid state 1 H nuclear magnetic resonance (NMR) spin-lattice relaxation, single-crystal X-ray diffraction, electronic structure calculations in both isolated molecules and in clusters of molecules that mimic the crystal structure, field emission scanning electron microscopy, differential scanning calorimetry, and high resolution 1 H NMR spectroscopy. The solid state 1 H spin-lattice relaxation experiments allow us to observe the temperature dependence of the parameters that characterize methyl group rotation in both compounds and in mixtures of the two compounds. In the mixtures, both types of methyl groups (that is, molecules of 1 and 2) can be observed independently and simultaneously at low temperatures because the solid state 1 H spin-lattice relaxation is appropriately described by a double exponential. We have followed the conversion 1 → 2 over periods of two years. The solid state 1 H spin-lattice relaxation experiments in pure samples of 1 and 2 indicate that there is a distribution of NMR activation energies for methyl group rotation in 1 but not in 2 and we are able to explain this in terms of the particle sizes seen in the field emission scanning electron microscopy images. Copyright © 2017 Elsevier Inc. All rights reserved.

Solvothermal synthesis of TiO2 nanocrystals with {001} facets using titanic acid nanobelts for superior photocatalytic activity

NASA Astrophysics Data System (ADS)

Cao, Yuhui; Zong, Lanlan; Li, Qiuye; Li, Chen; Li, Junli; Yang, Jianjun

2017-01-01

Anatase TiO2 nanocrystals exposed with {001} facets were fabricated by solvothermal strategy in HF-C4H9OH mixed solution, using titanic acid nanobelts (TAN) as a precursor. The shape of TAN is a long flat plane with a high aspect ratio, and F- is easily adsorbed on the surface of the nanobelts, inducing a higher exposure of {001} facet of TiO2 nanoparticles during the structure reorganization. The exposed percentage of {001} facets could vary from 40 to 77% by adjusting the amount of HF. The as-prepared samples were characterized by transmission electron microscopy, N2 adsorption-desorption isotherms, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscope. The photocatalytic measurement showed that TiO2 nanocrystals with 77% {001} facets exhibited much superior photocatalytic activity for photodegradation of methyl orange, methylene blue, and rhodamine B. And what's more, the mineralization rate of methyl orange was as high as 96% within 60 min. The photocatalytic enhancement is due to a large amount of the high energetic {001} facets exposing, the special truncated octahedral morphology and a stronger ability for dyes adsorption.

3-methyl-1,2,3-butanetricarboxylic acid: An atmospheric tracer for terpene secondary organic aerosol

NASA Astrophysics Data System (ADS)

Szmigielski, Rafal; Surratt, Jason D.; Gómez-González, Yadian; Van der Veken, Pieter; Kourtchev, Ivan; Vermeylen, Reinhilde; Blockhuys, Frank; Jaoui, Mohammed; Kleindienst, Tadeusz E.; Lewandowski, Michael; Offenberg, John H.; Edney, Edward O.; Seinfeld, John H.; Maenhaut, Willy; Claeys, Magda

2007-12-01

Highly oxygenated compounds assigned to be oxidation products of α-pinene have recently been observed in substantial concentrations in ambient aerosols. Here, we confirm the unknown α-pinene tracer compound with molecular weight (MW) 204 as the C8-tricarboxylic acid 3-methyl-1,2,3-butanetricarboxylic acid. Its gas and liquid chromatographic behaviors and its mass spectral characteristics in electron ionization and negative ion electrospray ionization perfectly agree with those of a synthesized reference compound. The formation of this compound is explained by further reaction of cis-pinonic acid involving participation of the OH radical. This study illustrates that complex, multi-generation chemistry holds for the photooxidation of α-pinene in the presence of NOx.

Hydrogen bonded 2-methyl-1H-imidazol-3-ium 3,5-dinitrobenzoate 3,5-dinitrobenzoic acid, a new optical crystal: Evaluation of properties by structural, spectral, quantum chemical calculations, Z-scan and Hirshfeld studies

NASA Astrophysics Data System (ADS)

Sathya, K.; Dhamodharan, P.; Dhandapani, M.

2018-03-01

A new hydrgen bonded proton transfer complex, 2-methyl imidazolium 3, 5-dinitrobenzoate 3,5-dinitro benzoic acid (MIDB) was synthesized by the reaction between 2-methyl imidazole with 3,5-dinitro benzoic acid (1:2) in methanol solvent at room temperature. The crystals were subjected to FT-IR spectral analysis to confirm the functional groups of the new compound. Single crystal XRD analysis reveals that MIDB belongs to monoclinic system with P21/c space group. The asymmetric unit consists of one 2-methyl imidazolium cation, one 3, 5-dinitrobenzoate anion and one uncharged 3,5-dinitro benzoic acid moiety. Experimental NMR spectroscopic data and theoretically calculated NMR data correlated very well to estabilish the exact carbon skeleton and hydrogen environment in the molecular structure of MIDB. The thermal stability of the compound was investigated by thermogravimetry and differential thermal analysis (TG-DTA). Computational studies such as optimization of molecular geometry, natural bond analysis (NBO), Mulliken population analysis and HOMO-LUMO analysis were performed using Gaussian 09 software by B3LYP method at 6-31 g basis set level. The calculated first-order polarizability (β) of MIDB from computational studies is 4.1752 × 10-30 esu, which is 32 times greater than that of urea. UV-vis-NIR spectral studies revealed that the MIDB has a large optical transparency window. The optical nonlinearities of MIDB have been investigated by Z-scan technique with Hesbnd Ne laser radiation of wavelength 632.8 nm. Hirshfeld analysis indicate O⋯H/H⋯O interactions are the superior interactions confirming excessive hydrogen bond net work in the molecular structure.

Methylation of DNA

PubMed Central

Gold, Marvin; Gefter, Malcolm; Hausmann, Rudolph; Hurwitz, Jerard

1966-01-01

The methylated bases of DNA are formed by the transfer of the methyl group from S-adenosylmethionine to a polynucleotide acceptor. This transfer is catalyzed by highly specific enzymes which recognize a limited number of available sites in the DNA. The mechanism for the recognition is presently unknown. In some instances, there is evidence that other cellular components, such as lipopolysaccharides, can influence the methylation reaction. Certain bacteriophages induce new methylases upon infection of their hosts. Phage T3 is unique in establishing an environment in which methylation of neither the phage nor the host nucleic acid can occur. By superinfecting T3-infected cells with other phages, the latter can be obtained with methyl-deficient DNA. Although a great deal is known about the enzymology of the methylation reaction, and there appears to be a strong correlation between the in vitro and in vivo reactions, studies in which DNA is either supermethylated or totally unmethylated have not yielded any insight as to what the possible function of the methylated bases may be. PMID:5338563

Magnetically separable core–shell ZnFe{sub 2}O{sub 4}@ZnO nanoparticles for visible light photodegradation of methyl orange

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

Kulkarni, Suresh D., E-mail: suresh.dk@manipal.edu; Kumbar, Sagar; Menon, Samvit G.

Highlights: • Phase pure, magnetic ZnFe{sub 2}O{sub 4}@ZnO nanoparticles synthesized with excellent yield. • ZnFe{sub 2}O{sub 4}@ZnO displayed higher UV photocatalytic efficiency than ZnO nanoparticles. • First report on visible light photodegradation of methyl orange by ZnFe{sub 2}O{sub 4}@ZnO. • Excellent reusability of ZnFe{sub 2}O{sub 4}@ZnO nanoparticles observed for azo dye removal. - Abstract: Visible light photodegradation of aqueous methyl orange using magnetically separable core–shell ZnFe{sub 2}O{sub 4}@ZnO nanoparticles is reported. A combination of low temperature (190 °C) microwave synthesis and hydrothermal method were used to prepare phase pure material with excellent yield (95%). The magnetic separability, surface area ofmore » 41 m{sup 2}/g and visible light absorption make ZnFe{sub 2}O{sub 4}@ZnO nanoparticles a good solar photocatalyst. ZnFe{sub 2}O{sub 4}@ZnO displayed greater UV photocatalytic efficiency than ZnO owing to the generation of large number of electron-hole pairs. Visible light photodegradation of MO using ZnFe{sub 2}O{sub 4}@ZnO nanoparticles is reported for the first time. Higher first order rate constants under both UV and visible light for core-shell nanoparticles suggested their superiority over its individual oxides. The ZnFe{sub 2}O{sub 4}@ZnO showed excellent reusability with high photocatalytic efficiencies suggesting its suitability for solar photocatalytic applications.« less

[Molecular docking of chlorogenic acid, 3,4-di-O-caffeoylquinic acid and 3,5-di-O-caffeoylquinic acid with human serum albumin].

PubMed

Zhou, Jing; Ma, Hong-yue; Fan, Xin-sheng; Xiao, Wei; Wang, Tuan-jie

2012-10-01

To investigate the mechanism of binding of human serum albumin (HSA) with potential sensitinogen, including chlorogenic acid and two isochlorogenic acids (3,4-di-O-caffeoylquinic acid and 3,5-di-O-caffeoylquinic acid). By using the docking algorithm of computer-aided molecular design and the Molegro Virtual Docker, the crystal structures of HSA with warfarin and diazepam (Protein Data Bank ID: 2BXD and 2BXF) were selected as molecular docking receptors of HSA sites I and II. According to docking scores, key residues and H-bond, the molecular docking mode was selected and confirmed. The molecular docking of chlorogenic acid and two isochlorogenic acids on sites I and II was compared based on the above design. The results from molecular docking indicated that chlorogenic acid, 3,4-di-O-caffeoylquinic acid and 3,5-di-O-caffeoylquinic acid could bind to HSA site I by high affinity scores of -112.3, -155.3 and -153.1, respectively. They could bind to site II on HSA by high affinity scores of -101.7, -138.5 and -133.4, respectively. In site I, two isochlorogenic acids interacted with the key apolar side-chains of Leu238 and Ala291 by higher affinity scores than chlorogenic acid. Furthermore, the H-bonds of isochlorogenic acids with polar residues inside the pocket and at the entrance of the pocket were different from chlorogenic acid. Moreover, the second coffee acyl of isochlorogenic acid occupied the right-hand apolar compartment in the pocket of HSA site I. In site I, the second coffee acyl of isochlorogenic acid formed the H-bonds with polar side-chains, which contributed isochlorogenic acid to binding with site II of HSA. The isochlorogenic acids with two coffee acyls have higher binding abilities with HSA than chlorogenic acid with one coffee acyl, suggesting that isochlorogenic acids binding with HSA may be sensitinogen.

Predicting heterocyclic ring coupling constants through a conformational search of tetra-O-methyl-(+)-catechin

Treesearch

Fred L. Tobiason; Richard W. Hemingway

1994-01-01

A GMMX conformational search routine gives a family of conformations that reflects the Boltzmann-averaged heterocyclic ring conformation as evidenced by accurate prediction of all three coupling constants observed for tetra-O-methyl-(+)-catechin.

Predicting heterocyclic ring coupling constants through a conformational search of tetra-o-methyl-(+)-catechin

Treesearch

Fred L. Tobiason; Richard w. Hemingway

1994-01-01

A GMMXe conformational search routine gives a family a conformations that reflects the boltzmann-averaged heterocyclic ring conformation as evidence by accurate prediction of all three coupling constants observed for tetra-O-methyl-(+)-catechin.

Identification of Differentially Methylated Sites with Weak Methylation Effects

PubMed Central

Tran, Hong; Zhu, Hongxiao; Wu, Xiaowei; Kim, Gunjune; Clarke, Christopher R.; Larose, Hailey; Haak, David C.; Westwood, James H.; Zhang, Liqing

2018-01-01

Deoxyribonucleic acid (DNA) methylation is an epigenetic alteration crucial for regulating stress responses. Identifying large-scale DNA methylation at single nucleotide resolution is made possible by whole genome bisulfite sequencing. An essential task following the generation of bisulfite sequencing data is to detect differentially methylated cytosines (DMCs) among treatments. Most statistical methods for DMC detection do not consider the dependency of methylation patterns across the genome, thus possibly inflating type I error. Furthermore, small sample sizes and weak methylation effects among different phenotype categories make it difficult for these statistical methods to accurately detect DMCs. To address these issues, the wavelet-based functional mixed model (WFMM) was introduced to detect DMCs. To further examine the performance of WFMM in detecting weak differential methylation events, we used both simulated and empirical data and compare WFMM performance to a popular DMC detection tool methylKit. Analyses of simulated data that replicated the effects of the herbicide glyphosate on DNA methylation in Arabidopsis thaliana show that WFMM results in higher sensitivity and specificity in detecting DMCs compared to methylKit, especially when the methylation differences among phenotype groups are small. Moreover, the performance of WFMM is robust with respect to small sample sizes, making it particularly attractive considering the current high costs of bisulfite sequencing. Analysis of empirical Arabidopsis thaliana data under varying glyphosate dosages, and the analysis of monozygotic (MZ) twins who have different pain sensitivities—both datasets have weak methylation effects of <1%—show that WFMM can identify more relevant DMCs related to the phenotype of interest than methylKit. Differentially methylated regions (DMRs) are genomic regions with different DNA methylation status across biological samples. DMRs and DMCs are essentially the same concepts, with

Positional isomerization of trans-3-hexadecenoic acid employing 2-amino-2-methyl-propanol as a derivatizing agent for ethylenic bond location by gas chromatography/mass spectrometry.

PubMed

Lamberto, M; Ackman, R G

1995-09-20

The effect of derivatization with 2-amino-2-methyl-propanol on trans-3-hexadecenoic acid was investigated as part of the identification of the trans-3-hexadecenoic acid in two Nova Scotian seaweeds. After the extraction of the total fatty acids and their methylation, the monoenoic trans fraction was isolated by thin-layer chromatography on silica gels impregnated with silver nitrate. This fraction was first analyzed by gas chromatography and showed the presence of the trans-3-hexadecenoic acid; other fatty acids were not present. The isolated fraction was derivatized with 2-amino-2-methyl-propanol prior to analysis by gas chromatography/mass spectrometry. The chromatogram obtained showed the presence of a positional isomer formed during the derivatization of the trans-3-hexadecenoic acid. The mass spectrum showed a prominent [M+H] and diagnostic ions for the identification of the unknown isomer, corresponding to the 4,4-dimethyloxazoline (DMOX) derivative of a presumed 2-hexadecenoic acid. Definitive confirmation of the ethylenic bond position was obtained by oxidative ozonolysis of the DMOX derivatives of the fatty acids under investigation. Infrared spectroscopy showed that the artifact formed during the DMOX derivatization of trans-3-hexadecenoic acid was the DMOX derivative of cis-2-hexadecenoic acid.

Aedes aegypti juvenile hormone acid methyl transferase, the ultimate enzyme in the biosynthetic pathway of juvenile hormone III, exhibits substrate control

USDA-ARS?s Scientific Manuscript database

We report on the cloning, sequencing, characterization, 3D modeling and docking of Aedes aegypti juvenile hormone acid methyl transferase (AeaJHAMT), the enzyme that converts juvenile hormone acid (JHA) into juvenile hormone (JH). Purified recombinant AeaJHAMT was extensively characterized for enzym...

40 CFR 180.419 - Chlorpyrifos-methyl; tolerances for residues.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Chlorpyrifos-methyl; tolerances for... § 180.419 Chlorpyrifos-methyl; tolerances for residues. (a) General. (1) Tolerances are established for the combined residues of the insecticide chlorpyrifos-methyl [O,-O,-dimethyl O-(3,5,6-trichloro-2...

40 CFR 180.419 - Chlorpyrifos-methyl; tolerances for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Chlorpyrifos-methyl; tolerances for... § 180.419 Chlorpyrifos-methyl; tolerances for residues. (a) General. (1) Tolerances are established for the combined residues of the insecticide chlorpyrifos-methyl [O,-O,-dimethyl O-(3,5,6-trichloro-2...

40 CFR 180.419 - Chlorpyrifos-methyl; tolerances for residues.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Chlorpyrifos-methyl; tolerances for... § 180.419 Chlorpyrifos-methyl; tolerances for residues. (a) General. (1) Tolerances are established for the combined residues of the insecticide chlorpyrifos-methyl [O,-O,-dimethyl O-(3,5,6-trichloro-2...

40 CFR 180.419 - Chlorpyrifos-methyl; tolerances for residues.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Chlorpyrifos-methyl; tolerances for... § 180.419 Chlorpyrifos-methyl; tolerances for residues. (a) General. (1) Tolerances are established for the combined residues of the insecticide chlorpyrifos-methyl [O,-O,-dimethyl O-(3,5,6-trichloro-2...

Methyl salicylate 2-O-β-D-lactoside, a novel salicylic acid analogue, acts as an anti-inflammatory agent on microglia and astrocytes

PubMed Central

2011-01-01

Background Neuroinflammation has been known to play a critical role in the pathogenesis of Alzheimer's disease (AD). Activation of microglia and astrocytes is a characteristic of brain inflammation. Epidemiological studies have shown that long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) delays the onset of AD and suppresses its progression. Methyl salicylate-2-O-β-D-lactoside (DL0309) is a new molecule chemically related to salicylic acid. The present study aimed to evaluate the anti-inflammatory effects of DL0309. Findings Our studies show that DL0309 significantly inhibits lipopolysaccharide (LPS)-induced release of the pro-inflammatory cytokines IL-6, IL-1β, and TNF-α; and the expression of the inflammation-related proteins iNOS, COX-1, and COX-2 by microglia and astrocytes. At a concentration of 10 μM, DL0309 prominently inhibited LPS-induced activation of NF-κB in glial cells by blocking phosphorylation of IKK and p65, and by blocking IκB degradation. Conclusions We demonstrate here for the first time that DL0309 exerts anti-inflammatory effects in glial cells by suppressing different pro-inflammatory cytokines and iNOS/NO. Furthermore, it also regulates the NF-κB signaling pathway by blocking IKK and p65 activation and IκB degradation. DL0309 also acts as a non-selective COX inhibitor in glial cells. These studies suggest that DL0309 may be effective in the treatment of neuroinflammatory disorders, including AD. PMID:21831328

21 CFR 573.637 - Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic...

Code of Federal Regulations, 2010 CFR

2010-04-01

... RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing...-octadecadienoic acids). The food additive, methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10... conditions: (a) The food additive is manufactured by the reaction of refined sunflower oil with methanol to...

21 CFR 573.637 - Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic...

Code of Federal Regulations, 2013 CFR

2013-04-01

... RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing...-octadecadienoic acids). The food additive, methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10... conditions: (a) The food additive is manufactured by the reaction of refined sunflower oil with methanol to...

21 CFR 573.637 - Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic...

Code of Federal Regulations, 2012 CFR

2012-04-01

... RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing...-octadecadienoic acids). The food additive, methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10... conditions: (a) The food additive is manufactured by the reaction of refined sunflower oil with methanol to...

21 CFR 573.637 - Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic...

Code of Federal Regulations, 2011 CFR

2011-04-01

... RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing...-octadecadienoic acids). The food additive, methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10... conditions: (a) The food additive is manufactured by the reaction of refined sunflower oil with methanol to...

21 CFR 573.637 - Methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10, cis-12-octadecadienoic...

Code of Federal Regulations, 2014 CFR

2014-04-01

... RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing...-octadecadienoic acids). The food additive, methyl esters of conjugated linoleic acid (cis-9, trans-11 and trans-10... conditions: (a) The food additive is manufactured by the reaction of refined sunflower oil with methanol to...

Toxicity of methyl parathion to bats: Mortality and coordination loss

USGS Publications Warehouse

Clark, D.R.

1986-01-01

The 24-h oral LD50 of methyl parathion (phosphorothioic acid O,O-dimethyl O-(4-nitrophenyl) ester) to little brown bats (Myotis lucifugus) (372 mg/kg) was 8.5 times the LD50 for mice (Mus musculus) (44 mg/kg). However, orally dosed mice either died or appeared behaviorally normal after 2 to 3 h, whereas many dosed bats, although alive at 24 h, could not right themselves when placed on their backs. The oral dose estimated to cause this loss of coordination in 50% of a sample of big brown bats (Eptesicus fuscus) was one-third or less the LD50 of this species. Cholinesterase activity depression in brains of little brown bats was similar whether dosage was oral or dermal. With death as the criterion, bats proved relatively insensitive to methyl parathion in 24-h tests, but considerations of the chemical's potential to cause coordination loss, leading to capture and death by predators, coupled with bats' naturally low reproductive rates, suggest possible injury to exposed bat populations.

Aristolic Acid Derivatives from the Bark of Antidesma ghaesembilla.

PubMed

Schäfer, Sibylle; Schwaiger, Stefan; Stuppner, Hermann

2017-08-01

Antidesma ghaesembilla is an important medicinal and food plant in many Asian countries. Ten substances could be isolated from the dichloromethane and methanol extract: sitostenone ( 3 ), daucosterol ( 4 ), chavibetol ( 5 ), asperphenamate ( 6 ), protocatechuic acid ( 7 ), vanillic acid-4- O - β -D-glucoside ( 8 ), 1- O - β -D-glucopyranosyl-3- O -methyl-phloroglucinol ( 9 ), and aristolic acid II-8- O - β -D-glucoside ( 10 ), and two new aristolic acid derivatives, 10-amino-5,7-dimethoxy-aristolic acid II (= 6-amino-9,11-dimethoxyphenanthro[3,4- d ]-1,3-dioxole-5-carboxylic acid; 1 ) and 5,7-dimethoxy-aristolochic acid II (= 9,11-dimethoxy-6-nitrophenantro[3,4- d ]-1,3-dioxole-5-carboxylic acid; 2 ). Exposure to humans of some of these compounds is associated with a severe disease today known as aristolochic acid nephropathy. Therefore, the traditional usage of this plant has to be reconsidered carefully. Georg Thieme Verlag KG Stuttgart · New York.

A simplified and efficient method for the analysis of fatty acid methyl esters suitable for large clinical studies.

PubMed

Masood, Athar; Stark, Ken D; Salem, Norman

2005-10-01

Conventional sample preparation for fatty acid analysis is a complicated, multiple-step process, and gas chromatography (GC) analysis alone can require >1 h per sample to resolve fatty acid methyl esters (FAMEs). Fast GC analysis was adapted to human plasma FAME analysis using a modified polyethylene glycol column with smaller internal diameters, thinner stationary phase films, increased carrier gas linear velocity, and faster temperature ramping. Our results indicated that fast GC analyses were comparable to conventional GC in peak resolution. A conventional transesterification method based on Lepage and Roy was simplified to a one-step method with the elimination of the neutralization and centrifugation steps. A robotics-amenable method was also developed, with lower methylation temperatures and in an open-tube format using multiple reagent additions. The simplified methods produced results that were quantitatively similar and with similar coefficients of variation as compared with the original Lepage and Roy method. The present streamlined methodology is suitable for the direct fatty acid analysis of human plasma, is appropriate for research studies, and will facilitate large clinical trials and make possible population studies.

Evidence for rRNA 2'-O-methylation plasticity: Control of intrinsic translational capabilities of human ribosomes.

PubMed

Erales, Jenny; Marchand, Virginie; Panthu, Baptiste; Gillot, Sandra; Belin, Stéphane; Ghayad, Sandra E; Garcia, Maxime; Laforêts, Florian; Marcel, Virginie; Baudin-Baillieu, Agnès; Bertin, Pierre; Couté, Yohann; Adrait, Annie; Meyer, Mélanie; Therizols, Gabriel; Yusupov, Marat; Namy, Olivier; Ohlmann, Théophile; Motorin, Yuri; Catez, Frédéric; Diaz, Jean-Jacques

2017-12-05

Ribosomal RNAs (rRNAs) are main effectors of messenger RNA (mRNA) decoding, peptide-bond formation, and ribosome dynamics during translation. Ribose 2'-O-methylation (2'-O-Me) is the most abundant rRNA chemical modification, and displays a complex pattern in rRNA. 2'-O-Me was shown to be essential for accurate and efficient protein synthesis in eukaryotic cells. However, whether rRNA 2'-O-Me is an adjustable feature of the human ribosome and a means of regulating ribosome function remains to be determined. Here we challenged rRNA 2'-O-Me globally by inhibiting the rRNA methyl-transferase fibrillarin in human cells. Using RiboMethSeq, a nonbiased quantitative mapping of 2'-O-Me, we identified a repertoire of 2'-O-Me sites subjected to variation and demonstrate that functional domains of ribosomes are targets of 2'-O-Me plasticity. Using the cricket paralysis virus internal ribosome entry site element, coupled to in vitro translation, we show that the intrinsic capability of ribosomes to translate mRNAs is modulated through a 2'-O-Me pattern and not by nonribosomal actors of the translational machinery. Our data establish rRNA 2'-O-Me plasticity as a mechanism providing functional specificity to human ribosomes.

Structural characterization of saturated branched chain fatty acid methyl esters by collisional dissociation of molecular ions generated by electron ionization.

PubMed

Ran-Ressler, Rinat R; Lawrence, Peter; Brenna, J Thomas

2012-01-01

Saturated branched chain fatty acids (BCFA) are present as complex mixtures in numerous biological samples. The traditional method for structure elucidation, electron ionization (EI) mass spectrometry, sometimes does not unambiguously enable assignment of branching in isomeric BCFA. Zirrolli and Murphy (Zirrolli , J. A. , and R. A. Murphy. 1993. Low-energy tandem mass spectrometry of the molecular ion derived from fatty acid methyl esters: a novel method for analysis of branched-chain fatty acids. J. Am. Soc. Mass Spectrom. 4: 223-229.) showed that the molecular ions of four BCFA methyl ester (BCFAME) yield highly characteristic fragments upon collisional dissociation using a triple quadrupole instrument. Here, we confirm and extend these results by analysis using a tabletop 3-D ion trap for activated molecular ion EI-MS/MS to 30 BCFAME. iso-BCFAME produces a prominent ion (30-100% of base peak) for [M-43] (M-C₃H₇), corresponding to the terminal isopropyl moiety in the original iso-BCFAME. Anteiso-FAME yield prominent ions (20-100% of base peak) corresponding to losses on both side of the methyl branch, [M-29] and [M-57], and tend to produce more prominent m/z 115 peaks corresponding to a cyclization product around the ester. Dimethyl and tetramethyl FAME, with branches separated by at least one methylene group, yield fragment on both sides of the sites of methyl branches that are more than 6 C away from the carboxyl carbon. EI-MS/MS yields uniquely specific ions that enable highly confident structural identification and quantification of BCFAME.

A novel methylation derivatization method for δ(18)O analysis of individual carbohydrates by gas chromatography/pyrolysis-isotope ratio mass spectrometry.

PubMed

Lehmann, Marco M; Fischer, Maria; Blees, Jan; Zech, Michael; Siegwolf, Rolf T W; Saurer, Matthias

2016-01-15

The oxygen isotope ratio (δ(18)O) of carbohydrates derived from animals, plants, sediments, and soils provides important information about biochemical and physiological processes, past environmental conditions, and geographical origins, which are otherwise not available. Nowadays, δ(18)O analyses are often performed on carbohydrate bulk material, while compound-specific δ(18)O analyses remain challenging and methods for a wide range of individual carbohydrates are rare. To improve the δ(18)O analysis of individual carbohydrates by gas chromatography/pyrolysis-isotope ratio mass spectrometry (GC/Pyr-IRMS) we developed a new methylation derivatization method. Carbohydrates were fully methylated within 24 h in an easy-to-handle one-pot reaction in acetonitrile, using silver oxide as proton acceptor, methyl iodide as methyl group carrier, and dimethyl sulfide as catalyst. The precision of the method ranged between 0.12 and 1.09‰ for the δ(18)O values of various individual carbohydrates of different classes (mono-, di-, and trisaccharides, alditols), with an accuracy of a similar order of magnitude, despite high variation in peak areas. Based on the δ(18)O values of the main isomers, important monosaccharides such as glucose and fructose could also be precisely analyzed for the first time. We tested the method on standard mixtures, honey samples, and leaf carbohydrates extracted from Pinus sylvestris, showing that the method is also applicable to different carbohydrate mixtures. The new methylation method shows unrivalled accuracy and precision for δ(18)O analysis of various individual carbohydrates; it is fast and easy-to-handle, and may therefore find wide-spread application. Copyright © 2015 John Wiley & Sons, Ltd.

Jasmonic acid/methyl jasmonate accumulate in wounded soybean hypocotyls and modulate wound gene expression.

PubMed Central

Creelman, R A; Tierney, M L; Mullet, J E

1992-01-01

Jasmonic acid (JA) and its methyl ester, methyl jasmonate (MeJA), are plant lipid derivatives that resemble mammalian eicosanoids in structure and biosynthesis. These compounds are proposed to play a role in plant wound and pathogen responses. Here we report the quantitative determination of JA/MeJA in planta by a procedure based on the use of [13C,2H3]MeJA as an internal standard. Wounded soybean (Glycine max [L] Merr. cv. Williams) stems rapidly accumulated MeJA and JA. Addition of MeJA to soybean suspension cultures also increased mRNA levels for three wound-responsive genes (chalcone synthase, vegetative storage protein, and proline-rich cell wall protein) suggesting a role for MeJA/JA in the mediation of several changes in gene expression associated with the plants' response to wounding. Images PMID:1594598

Sulfur amino acid and methyl donor status of corn-soy diets fed to starting broiler chicks and turkey poults.

PubMed

Pesti, G M; Harper, A E; Sunde, M L

1979-11-01

Experiments were conducted to determine the effects of supplementing corn-soy-bean meal-white grease diets with sulfur amino acids and methyl group donors for starting broiler-strain chicks. The diets (23% protein and 3200 kcal ME/kg) were fed to quadruplicate lots of chicks in battery brooders. The diets were calculated to contain .37% methionine, .37% cystine, and 1499 mg/kg choline. Chemical and microbiological assays yielded values of .32% and .42% for methionine and cystine content respectively. Results of 5 chick experiments showed that supplementing this diet with .23% DL-methionine significantly (P less than .05) improved 3 week-gain (375 vs. 415 g) and feed/gain (1.54 vs. 1.47) over that obtained with the basal diet. When L-cystine and 2(CaSO4).H2O failed to give a significant (P greater than .05) response, compounds capable of donating methyl groups were fed. Significant (P less than .05) responses in gain (404 and 420) and feed/gain (1.48 and 1.51) over the basal were obtained with choline and betaine. These responses were not significantly (P greater than .05) different from that obtained with methionine. Serine and sodium formate failed to give consistent responses. Using a poult diet of 28% protein and 2800 kcal ME/kg, a significant (P less than .05) response to DL-methionine was again observed, with intermediate responses to betaine, choline, and serine. It is concluded that (within the limits of the experimental model) corn-soy type diets contain an adequate amount of total sulfur amino acid for chicks, but not poults, when sufficient choline or betaine are provided.

Methyl group turnover on methyl-accepting chemotaxis proteins during chemotaxis by Bacillus subtilis

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

Thoelke, M.S.; Casper, J.M.; Ordal, G.W.

1990-02-05

The addition of attractant to Bacillus subtilis briefly exposed to radioactive methionine causes an increase of labeling of the methyl-accepting chemotaxis proteins. The addition of attractant to cells radiolabeled for longer times shows no change in the extent of methylation. Therefore, the increase in labeling for the briefly labeled cells is due to an increased turnover of methyl groups caused by attractant. All amino acids gave enhanced turnover. This turnover lasted for a prolonged time, probably spanning the period of smooth swimming caused by the attractant addition. Repellent did not affect the turnover when added alone or simultaneously with attractant.more » Thus, for amino acid attractants, the turnover is probably the excitatory signal, which is seen to extend long into or throughout the adaptation period, not just at the start of it.« less

Probing the Active Center of Benzaldehyde Lyase with Substitutions and the Pseudosubstrate Analogue Benzoylphosphonic Acid Methyl Ester

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

Brandt, Gabriel S.; Nemeria, Natalia; Chakraborty, Sumit

2008-07-28

Benzaldehyde lyase (BAL) catalyzes the reversible cleavage of (R)-benzoin to benzaldehyde utilizing thiamin diphosphate and Mg{sup 2+} as cofactors. The enzyme is important for the chemoenzymatic synthesis of a wide range of compounds via its carboligation reaction mechanism. In addition to its principal functions, BAL can slowly decarboxylate aromatic amino acids such as benzoylformic acid. It is also intriguing mechanistically due to the paucity of acid-base residues at the active center that can participate in proton transfer steps thought to be necessary for these types of reactions. Here methyl benzoylphosphonate, an excellent electrostatic analogue of benzoylformic acid, is used tomore » probe the mechanism of benzaldehyde lyase. The structure of benzaldehyde lyase in its covalent complex with methyl benzoylphosphonate was determined to 2.49 {angstrom} (Protein Data Bank entry 3D7K) and represents the first structure of this enzyme with a compound bound in the active site. No large structural reorganization was detected compared to the complex of the enzyme with thiamin diphosphate. The configuration of the predecarboxylation thiamin-bound intermediate was clarified by the structure. Both spectroscopic and X-ray structural studies are consistent with inhibition resulting from the binding of MBP to the thiamin diphosphate in the active centers. We also delineated the role of His29 (the sole potential acid-base catalyst in the active site other than the highly conserved Glu50) and Trp163 in cofactor activation and catalysis by benzaldehyde lyase.« less

Esterification of oil adsorbed on palm decanter cake into methyl ester using sulfonated rice husk ash as heterogeneous acid catalyst

NASA Astrophysics Data System (ADS)

Hindryawati, Noor; Erwin, Maniam, Gaanty Pragas

2017-02-01

Palm Decanter cake (PDC) which is categorized as the waste from palm oil mill has been found to contain residual crude palm oil. The oil adsorbed on the PDC (PDC-oil) can be extracted and potentially used as feedstock for biodiesel production. Feedstock from waste like PDC-oil is burdened with high free fatty acids (FFAs) which make the feedstock difficult to be converted into biodiesel using basic catalyst. Therefore, in this study, a solid acid, RHA-SO3H catalyst was synthesized by sulfonating rice husk ash (RHA) with concentrated sulfuric acid. The RHA-SO3H prepared was characterized with TGA, FTIR, BET, XRD, FE-SEM, and Hammett indicators (methyl red, bromophenol blue, and crystal violet). PDC was found to have about 11.3 wt. % oil recovered after 1 hour extraction using ultrasound method. The presence of sulfonate group was observed in IR spectrum, and the surface area of RHA-SO3H was reduced to 37 m2.g-1 after impregnation of sulfonate group. The RHA-SO3H catalyst showed that it can work for both esterification of free fatty acid which is present in PDC-oil, and transesterification of triglycerides into methyl ester. The results showed highest methyl ester content of 70.2 wt.% at optimal conditions, which was 6 wt.% catalyst amount, methanol to oil molar ratio of 17:1 for 5 hours at 120 °C.

Methylated purines in urinary stones.

PubMed

Safranow, Krzysztof; Machoy, Zygmunt

2005-08-01

The aim of the study was to measure the content of methylated purines that appear as admixtures in uric acid stones. We analyzed urinary calculi from 48 residents of Western Pomerania who underwent surgery at the urology ward in Szczecin. Stone samples were dissolved in 0.1 mol/L NaOH. Extracts were diluted in 50 mmol/L KH(2)PO(4) and analyzed by reversed-phase HPLC with ultraviolet detection and use of a gradient of methanol concentration and pH. Uric acid was the main component of 9 stones. All 9 showed admixtures of 9 other purine derivatives: endogenous purine breakdown products (xanthine, hypoxanthine, and 2,8-dihydroxyadenine) and exogenous methyl derivatives of uric acid and xanthine (1-, 3-, and 7-methyluric acid; 1,3-dimethyluric acid; and 3- and 7-methylxanthine). Amounts of these purine derivatives ranged from the limit of detection to 12 mg/g of stone weight and showed a strong positive correlation (Spearman rank correlation coefficients, 0.63-0.94) with the uric acid content of the samples. The main methylated purine in the stones was 1-methyluric acid. Urinary purines at concentrations below their saturation limits may coprecipitate in samples supersaturated with uric acid and appear as admixtures in urinary stones. The amount of each purine depends on its average urinary excretion, similarity to the chemical structure of uric acid, and concentration of the latter in the stone. These findings suggest that purines in stones represent a substitutional solid solution with uric acid as solvent. Methylxanthines, which are ubiquitous components of the diet, drugs, and uric acid calculi, may be involved in the pathogenesis of urolithiasis.

The O-methyltransferase PMT2 mediates methylation of pinosylvin in Scots pine.

PubMed

Paasela, Tanja; Lim, Kean-Jin; Pietiäinen, Milla; Teeri, Teemu H

2017-06-01

Heartwood extractives are important determinants of the natural durability of pine heartwood. The most important phenolic compounds affecting durability are the stilbenes pinosylvin and its monomethylether, which in addition have important functions as phytoalexins in active defense. A substantial portion of the synthesized pinosylvin is 3-methoxylated but the O-methyltransferase responsible for this modification has not been correctly identified. We studied the expression of the stilbene pathway during heartwood development as well as in response to wounding of xylem and UV-C treatment of needles. We isolated and enzymatically characterized a novel O-methyltransferase, PMT2. The methylated product was verified as pinosylvin monomethylether using ultra performance liquid chromatography-tandem mass spectrometry and high performance liquid chromatography analyses. The PMT2 enzyme was highly specific for stilbenes as substrate, in contrast to caffeoyl-CoA O-methyltransferase (CCoAOMT) and PMT1 that were multifunctional. Expression profile and multifunctional activity of CCoAOMT suggest that it might have additional roles outside lignin biosynthesis. PMT1 is not involved in the stilbene pathway and its biological function remains an open question. We isolated a new specific O-methyltransferase responsible for 3-methoxylation of pinosylvin. Expression of PMT2 closely follows stilbene biosynthesis during developmental and stress induction. We propose that PMT2 is responsible for pinosylvin methylation in Scots pine (Pinus sylvestris), instead of the previously characterized methyltransferase, PMT1. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Influence of (9Z)-12-hydroxy-9-dodecenoic acid and methyl jasmonate on plant protein phosphorylation.

PubMed

Tarchevsky, I A; Karimova, F G; Grechkin, A N; Moukhametchina, N U

2000-12-01

The products of the lipoxygenase pathway, methyl jasmonic acid (MeJA) and (9Z)-12-hydroxy-9-dodecenoic acid (HDA), hardly changed the relative level of phosphorylated polypeptides (RLPPs) during 2 h of incubation: 15 and 17 kDa RLPPs were enhanced by HDA, but decreased by MeJA. RLPPs of 73 and 82 kDa were increased by both compounds. MeJA and HDA treatment induced specific and unspecific effects in some RLPPs. It was shown that HDA and MeJA increased protein kinase activity in the presence of 1 microM cAMP.

Laboratory study of methyl isocyanate ices under astrophysical conditions

NASA Astrophysics Data System (ADS)

Maté, B.; Molpeceres, G.; Timón, V.; Tanarro, I.; Escribano, R.; Guillemin, J. C.; Cernicharo, J.; Herrero, V. J.

2017-10-01

Methyl isocyanate has been recently detected in comet 67P/Churyumov-Gerasimenko (67P/CG) and in the interstellar medium. New physicochemical studies on this species are now necessary as tools for subsequent studies in astrophysics. In this work, infrared spectra of solid CH3NCO have been obtained at temperatures of relevance for astronomical environments. The spectra are dominated by a strong, characteristic multiplet feature at 2350-2250 cm-1, which can be attributed to the asymmetric stretching of the NCO group. A phase transition from amorphous to crystalline methyl isocyanate is observed at ˜90 K. The band strengths for the absorptions of CH3NCO in ice at 20 K have been measured. Deuterated methyl isocyanate is used to help with the spectral assignment. No X-ray structure has been reported for crystalline CH3NCO. Here we advance a tentative theoretical structure, based on density functional theory (DFT) calculations, derived taking the crystal of isocyanic acid as a starting point. A harmonic theoretical spectrum is then calculated for the proposed structure and compared with the experimental data. A mixed ice of H2O and CH3NCO was formed by simultaneous deposition of water and methyl isocyanate at 20 K. The absence of new spectral features indicates that methyl isocyanate and water do not react appreciably at 20 K, but form a stable mixture. The high CH3NCO/H2O ratio reported for comet 67P/CG, and the characteristic structure of the 2350-2250 cm-1 band, makes it a very good candidate for future astronomical searches.

Synthesis of novel ganglioside GM4 analogues containing N-deacetylated and lactamized sialic acid: probes for searching new ligand structures for human L-selectin.

PubMed

Otsubo, N; Ishida, H; Kiso, M

2001-01-15

Novel ganglioside GM4 analogues, which contain N-deacetylated or lactamized sialic acid instead of usual N-acetylneuraminic acid, were synthesized in a highly efficient manner. (Methyl 4,7,8,9-tetra-O-acetyl-3,5-dideoxy-5-trifluoroacetamido-D-glycero-alpha-D-galacto-2-nonulopyranosylonate)-(2-->3)-4,6-di-O-acetyl-2-O-benzoyl-D-galactopyranosyl trichloroacetimidate was coupled with 2-(tetradecyl)hexadecanol to give the desired beta-glycoside in high yield. Successive O- and N-deacylation, and saponification of the methyl ester group afforded the N-deacetylated sialyl derivative that was converted by treatment with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride in Me2SO into the lactamized sialic acid-containing ganglioside GM4 analogue.

Protein methylation in pea chloroplasts. [Pisum sativum

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

Niemi, K.J.; Adler, J.; Selman, B.R.

1990-07-01

The methylation of chloroplast proteins has been investigated by incubating intact pea (Pisum sativum) chloroplasts with ({sup 3}H-methyl)-S-adenosylmethionine. Incubation in the light increases the amount of methylation in both the thylakoid and stromal fractions. Numerous thylakoid proteins serve as substrates for the methyltransfer reactions. Three of these thylakoid proteins are methylated to a significantly greater extent in the light than in the dark. The primary stromal polypeptide methylated is the large subunit of ribulose bisphosphate carboxylase/oxygenase. One other stromal polypeptide is also methylated much more in the light than in the dark. Two distinct types of protein methylation occur. Onemore » methylinkage is stable to basic conditions whereas a second type is base labile. The base-stable linkage is indicative of N-methylation of amino acid residues while base-lability is suggestive of carboxymethylation of amino acid residues. Labeling in the light increases the percentage of methylation that is base labile in the thylakoid fraction while no difference is observed in the amount of base-labile methylations in light-labeled and dark-labeled stromal proteins. Also suggestive of carboxymethylation is the detection of volatile ({sup 3}H)methyl radioactivity which increases during the labeling period and is greater in chloroplasts labeled in the light as opposed to being labeled in the dark; this implies in vivo turnover of the ({sup 3}H)methyl group.« less

Cavitation assisted synthesis of fatty acid methyl esters from sustainable feedstock in presence of heterogeneous catalyst using two step process.

PubMed

Dubey, Sumit M; Gole, Vitthal L; Gogate, Parag R

2015-03-01

The present work reports the intensification aspects for the synthesis of fatty acid methyl esters (FAME) from a non-edible high acid value Nagchampa oil (31 mg of KOH/g of oil) using two stage acid esterification (catalyzed by H₂SO₄) followed by transesterification in the presence of heterogeneous catalyst (CaO). Intensification aspects of both stages have been investigated using sonochemical reactors and the obtained degree of intensification has been established by comparison with the conventional approach based on mechanical agitation. It has been observed that reaction temperature for esterification reduced from 65 to 40 °C for the ultrasonic approach whereas there was a significant reduction in the optimum reaction time for transesterification from 4h for the conventional approach to 2.5h for the ultrasound assisted approach. Also the reaction temperature reduced marginally from 65 to 60 °C and yield increased from 76% to 79% for the ultrasound assisted approach. Energy requirement and activation energy for both esterification and transesterification was lower for the ultrasound based approach as compared to the conventional approach. The present work has clearly established the intensification obtained due to the use of ultrasound and also illustrated the two step approach for the synthesis of FAME from high acid value feedstock based on the use of heterogeneous catalyst for the transesterification step. Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of methyl jasmonate, salicylic acid, Headline and Stadium on root yield, sucrose yield, and storage properties

USDA-ARS?s Scientific Manuscript database

Methyl jasmonate (MeJA) and salicylic acid (SA) have been reported to enhance yield and protect crop plants and products against abiotic stresses and diseases. The effect of these compounds on sugarbeets, however, is unknown. Research was conducted in 2016 and 2017 to investigate the effects of an e...

40 CFR 721.1725 - Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1725 Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The...

40 CFR 721.1725 - Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1725 Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The...

40 CFR 721.1725 - Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1725 Benzoic acid, 3,3′-methyl-enebis [6 amino-, di-2-propenyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The...

Urinary retinoic acid receptor-β2 gene promoter methylation and hyaluronidase activity as noninvasive tests for diagnosis of bladder cancer.

PubMed

Eissa, Sanaa; Zohny, Samir F; Shehata, Hanan Hussien; Hegazy, Marwa G A; Salem, Ahmed M; Esmat, Mohamed

2012-04-01

We evaluated the significance of urinary retinoic acid receptor-β2 (RAR-β2) gene promoter methylation and hyaluronidase activity in comparison with voided urine cytology (VUC) in diagnosis of bladder cancer. This study included 100 patients diagnosed with bladder cancer, 65 patients with benign urological disorders and 51 healthy volunteers. Urine supernatant was used for determining hyaluronidase activity by zymography while urine sediment was used for cytology and detection of methylated RAR-β2 gene promoter by methylation specific nested PCR. The sensitivity and specificity were 53% and 90.5% for VUC, 65% and 89.7% for percent methylation fraction of RAR-β2 gene promoter, and 89% and 90.5% for hyaluronidase activity; combination of the three parameters increased sensitivity to 95%. A significant association was observed between investigated markers and advanced grade tumor. Combined use of RAR-β2 gene promoter methylation, hyaluronidase activity and VUC is promising non-invasive tool for bladder cancer detection. Copyright © 2012. Published by Elsevier Inc.

Delayed O-methylation of l-DOPA in MB-COMT-deficient mice after oral administration of l-DOPA and carbidopa.

PubMed

Tammimäki, Anne; Aonurm-Helm, Anu; Männistö, Pekka T

2018-04-01

1. Catechol-O-methyltransferase (COMT) is involved in the O-methylation of l-DOPA, dopamine, and other catechols. The enzyme is expressed in two isoforms: soluble (S-COMT), which resides in the cytoplasm, and membrane-bound (MB-COMT), which is anchored to intracellular membranes. 2. To obtain specific information on the functions of COMT isoforms, we studied how a complete MB-COMT deficiency affects the total COMT activity in the body, peripheral l-DOPA levels, and metabolism after l-DOPA (10 mg kg -1 ) plus carbidopa (30 mg kg -1 ) administration by gastric tube in wild-type (WT) and MB-COMT-deficient mice. l-DOPA and 3-O-methyl-l-DOPA (3-OMD) levels were assayed in plasma, duodenum, and liver. 3. We showed that the selective lack of MB-COMT did not alter the total COMT activity, COMT enzyme kinetics, l-DOPA levels, or the total O-methylation of l-DOPA but delayed production of 3-OMD in plasma and peripheral tissues.

Structure-function analyses of a caffeic acid O-methyltransferase from perennial ryegrass reveal the molecular basis for substrate preference.

PubMed

Louie, Gordon V; Bowman, Marianne E; Tu, Yi; Mouradov, Aidyn; Spangenberg, German; Noel, Joseph P

2010-12-01

Lignin forms from the polymerization of phenylpropanoid-derived building blocks (the monolignols), whose modification through hydroxylation and O-methylation modulates the chemical and physical properties of the lignin polymer. The enzyme caffeic acid O-methyltransferase (COMT) is central to lignin biosynthesis. It is often targeted in attempts to engineer the lignin composition of transgenic plants for improved forage digestibility, pulping efficiency, or utility in biofuel production. Despite intensive investigation, the structural determinants of the regiospecificity and substrate selectivity of COMT remain poorly defined. Reported here are x-ray crystallographic structures of perennial ryegrass (Lolium perenne) COMT (Lp OMT1) in open conformational state, apo- and holoenzyme forms and, most significantly, in a closed conformational state complexed with the products S-adenosyl-L-homocysteine and sinapaldehyde. The product-bound complex reveals the post-methyl-transfer organization of COMT's catalytic groups with reactant molecules and the fully formed phenolic-ligand binding site. The core scaffold of the phenolic ligand forges a hydrogen-bonding network involving the 4-hydroxy group that anchors the aromatic ring and thereby permits only metahydroxyl groups to be positioned for transmethylation. While distal from the site of transmethylation, the propanoid tail substituent governs the kinetic preference of ryegrass COMT for aldehydes over alcohols and acids due to a single hydrogen bond donor for the C9 oxygenated moiety dictating the preference for an aldehyde.

UV-induced solvent free synthesis of truxillic acid-bile acid conjugates

NASA Astrophysics Data System (ADS)

Koivukorpi, Juha; Kolehmainen, Erkki

2009-07-01

The solvent free UV-induced [2 + 2] intermolecular cycloaddition of two molecules of 3α-cinnamic acid ester of methyl lithocholate produced in 99% yield of α- and ɛ-truxillic acid-bis(methyl lithocholate) isomers, which possess two structurally different potential binding sites. A prerequisite for this effective solid state reaction is a proper self-assembled crystal structure of the starting conjugate crystallized from acetonitrile. The crystallization of cinnamic acid ester of methyl lithocholate from acetonitrile produces two different crystalline forms (polymorphs), which is the reason for the solid state formation of two isomers of truxillic acid-bis(methyl lithocholate).

Conversion of polar and non-polar algae oil lipids to fatty acid methyl esters with solid acid catalysts--A model compound study.

PubMed

Asikainen, Martta; Munter, Tony; Linnekoski, Juha

2015-09-01

Bio-based fuels are becoming more and more important due to the depleting fossil resources. The production of biodiesel from algae oil is challenging compared to terrestrial vegetable oils, as algae oil consists of polar fatty acids, such as phospholipids and glycolipids, as well as non-polar triglycerides and free fatty acids common in vegetable oils. It is shown that a single sulphonated solid acid catalyst can perform the esterification and transesterification reactions of both polar and non-polar lipids. In mild reaction conditions (60-70 °C) Nafion NR50 catalyst produces methyl palmitate (FAME) from the palmitic acid derivatives of di-, and tri-glyceride, free fatty acid, and phospholipid with over 80% yields, with the glycolipid derivative giving nearly 40% yields of FAME. These results demonstrate how the polar and non-polar lipid derivatives of algal oil can be utilised as feedstocks for biodiesel production with a single catalyst in one reaction step. Copyright © 2015 Elsevier Ltd. All rights reserved.

27 CFR 21.118 - Methyl n-butyl ketone.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Methyl n-butyl ketone. 21.118 Section 21.118 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU....118 Methyl n-butyl ketone. (a) Acidity (as acetic acid). 0.02 percent by weight, maximum. (b) Color...

27 CFR 21.118 - Methyl n-butyl ketone.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Methyl n-butyl ketone. 21.118 Section 21.118 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU....118 Methyl n-butyl ketone. (a) Acidity (as acetic acid). 0.02 percent by weight, maximum. (b) Color...

Semisynthesis, cytotoxicity, antiviral activity, and drug interaction liability of 7-O-methylated analogues of flavonolignans from milk thistle.

PubMed

Althagafy, Hanan S; Graf, Tyler N; Sy-Cordero, Arlene A; Gufford, Brandon T; Paine, Mary F; Wagoner, Jessica; Polyak, Stephen J; Croatt, Mitchell P; Oberlies, Nicholas H

2013-07-01

Silymarin, an extract of the seeds of milk thistle (Silybum marianum), is used as an herbal remedy, particularly for hepatoprotection. The main chemical constituents in silymarin are seven flavonolignans. Recent studies explored the non-selective methylation of one flavonolignan, silybin B, and then tested those analogues for cytotoxicity and inhibition of both cytochrome P450 (CYP) 2C9 activity in human liver microsomes and hepatitis C virus infection in a human hepatoma (Huh7.5.1) cell line. In general, enhanced bioactivity was observed with the analogues. To further probe the biological consequences of methylation of the seven major flavonolignans, a series of 7-O-methylflavonolignans were generated. Optimization of the reaction conditions permitted selective methylation at the phenol in the 7-position in the presence of each metabolite's 4-5 other phenolic and/or alcoholic positions without the use of protecting groups. These 7-O-methylated analogues, in parallel with the corresponding parent compounds, were evaluated for cytotoxicity against Huh7.5.1 cells; in all cases the monomethylated analogues were more cytotoxic than the parent compounds. Moreover, parent compounds that were relatively non-toxic and inactive or weak inhibitors of hepatitis C virus infection had enhanced cytotoxicity and anti-HCV activity upon 7-O-methylation. Also, the compounds were tested for inhibition of major drug metabolizing enzymes (CYP2C9, CYP3A4/5, UDP-glucuronsyltransferases) in pooled human liver or intestinal microsomes. Methylation of flavonolignans differentially modified inhibitory potency, with compounds demonstrating both increased and decreased potency depending upon the compound tested and the enzyme system investigated. In total, these data indicated that monomethylation modulates the cytotoxic, antiviral, and drug interaction potential of silymarin flavonolignans. Copyright © 2013 Elsevier Ltd. All rights reserved.

Abscisic acid-type sesquiterpenes and ansamycins from Amycolatopsis alba DSM 44262.

PubMed

Li, Xiao-Mei; Li, Xiao-Man; Lu, Chun-Hua

2017-10-01

Two new abscisic acid-type sesquiterpenes (1, 2), and one new ansamycin (3), together with four known ansamycins, namely ansacarbamitocins 4-7, were isolated from the fermentation extract of Amycolatopsis alba DSM 44262. The structures of the new compounds were elucidated to be (E)-3-methyl-5-(2,6,6-trimethyl-3-oxocyclohex-1-enyl)pent-2-enoic acid (1) and (E)-3-methyl-5-(2,6,6-trimethyl-4-oxocyclohex-2-enyl)pent-2-enoic acid (2), and 9-O-methylansacarbamitocin A1 (3), on the basis of comprehensive analysis of spectroscopic data, respectively. The antimicrobial activities were also evaluated for all seven compounds.

An evidence of C16 fatty acid methyl esters extracted from microalga for effective antimicrobial and antioxidant property.

PubMed

Davoodbasha, MubarakAli; Edachery, Baldev; Nooruddin, Thajuddin; Lee, Sang-Yul; Kim, Jung-Wan

2018-02-01

Fatty acid methyl esters (FAME) derived from lipids of microalgae is known to have wide bio-functional materials including antimicrobials. FAME is an ideal super-curator and superior anti-pathogenic. The present study evaluated the efficiency of FAME extracted from microalgae Scenedesmus intermedius as an antimicrobial agent against Gram positive (Staphylococcus aureus, Streptococcus mutans, and Bacillus cereus) Gram negative (Escherichia coli and Pseudomonas aeruginosa) bacteria and Fungi (Aspergillus parasiticus and Candida albicans). The minimal inhibitory concentration (MIC) for the gram negative bacteria was determined as 12-24 μg mL -1 , whereas MIC for gram positive bacteria was 24-48 μg mL -1 . MIC for the fungi was as high as 60-192 μg mL -1 . The FAME profiles determined by gas chromatography showed 18 methyl esters. Among them, pharmacologically active FAME such as palmitic acid methyl ester (C16:0) was detected at high percentage (23.08%), which accounted for the bioactivity. FAME obtained in this study exhibited a strong antimicrobial activity at the lowest MIC than those of recent reports. This result clearly indicated that FAME of S. intermedius has a strong antimicrobial and antioxidant property and that could be used as an effective resource against microbial diseases. Copyright © 2017. Published by Elsevier Ltd.

An Experimental and Kinetic Modeling Study of Methyl Decanoate Combustion

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

Sarathy, S M; Thomson, M J; Pitz, W J

2009-12-04

Biodiesel is a mixture of long chain fatty acid methyl esters derived from fats and oils. This research study presents opposed-flow diffusion flame data for one large fatty acid methyl ester, methyl decanoate, and uses the experiments to validate an improved skeletal mechanism consisting of 648 species and 2998 reactions. The results indicate that methyl decanoate is consumed via abstraction of hydrogen atoms to produce fuel radicals, which lead to the production of alkenes. The ester moiety in methyl decanoate leads to the formation of low molecular weight oxygenated compounds such as carbon monoxide, formaldehyde, and ketene.

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.

Adsorption of methyl orange on mesoporous γ-Fe2O3/SiO2 nanocomposites

NASA Astrophysics Data System (ADS)

Deligeer, W.; Gao, Y. W.; Asuha, S.

2011-02-01

Mesoporous γ-Fe2O3/SiO2 nanocomposite containing 30 mol% of γ-Fe2O3 was prepared by a template-free sol-gel method, and its removal ability for methyl orange (MO) was investigated. The nanocomposite was characterized using X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), Fourier transform infrared (FTIR) absorption measurements, nitrogen adsorption-desorption measurements, and magnetic measurements. The synthesized γ-Fe2O3/SiO2 nanocomposite has a mesoporous structure with an average pore size of 3.5 nm and a specific surface area of 245 m2/g, and it exhibits ferrimagnetic characteristics with the maximum saturation magnetization of 20.9 emu/g. The adsorption of MO on the nanocomposite reaches the maximum adsorbed percentage of ca. 80% within a few minutes, showing that most of MO can be removed in a short time. The MO adsorption data fit well with both Langmuir and Freundlich adsorption isotherms. The maximum adsorption capacity of MO is estimated to be 476 mg/g.

Work-Function and Surface Energy Tunable Cyanoacrylic Acid Small-Molecule Derivative Interlayer on Planar ZnO Nanorods for Improved Organic Photovoltaic Performance.

PubMed

Ambade, Swapnil B; Ambade, Rohan B; Bagde, Sushil S; Lee, Soo-Hyoung

2016-12-28

The issue of work-function and surface energy is fundamental to "decode" the critical inorganic/organic interface in hybrid organic photovoltaics, which influences important photovoltaic events like exciton dissociation, charge transfer, photocurrent (J sc ), open-circuit voltage (V oc ), etc. We demonstrate that by incorporating an interlayer of cyanoacrylic acid small molecular layer (SML) on solution-processed, spin-coated, planar ZnO nanorods (P-ZnO NRs), higher photovoltaic (PV) performances were achieved in both inverted organic photovoltaic (iOPV) and hybrid organic photovoltaic (HOPV) devices, where ZnO acts as an "electron-transporting layer" and as an "electron acceptor", respectively. For the tuned range of surface energy from 52.5 to 33 mN/m, the power conversion efficiency (PCE) in bulk heterojunction (BHJ) iOPVs based on poly(3-hexylthiophene) (P3HT) and phenyl-C 60 -butyric acid methyl ester (PC 60 BM) increases from 3.16% to 3.68%, and that based on poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene)-2-carboxylate-2-6-diyl)] (PTB7:Th):[6,6]-phenyl C 71 butyric acid methyl ester (PC 71 BM) photoactive BHJ increases from 6.55% to 8.0%, respectively. The improved PV performance in iOPV devices is majorly attributed to enhanced photocurrents achieved as a result of reduced surface energy and greater electron affinity from the covalent attachment of the strong electron-withdrawing cyano moiety, while that in HOPV devices, where PCE increases from 0.21% to 0.79% for SML-modified devices, is ascribed to a large increase in V oc benefitted due to reduced work function effected from the presence of strong dipole moment in SML that points away from P-ZnO NRs.

[Research on mercury methylation by Geobacter sulfurreducens and its influencing factors].

PubMed

Zou, Yan; Si, You-Bin; Yan, Xue; Chen, Yan

2012-09-01

Mercury methylation by Geobacter sulfurreducens and the effects of environmental factors were studied under laboratory conditions. The results showed that G. sulfurreducens could grow well in the presence of low concentrations of mercuric chloride, but its growth was inhibited to a certain extent, mainly expressed in the prolonged lag phase. G. sulfurreducens could transform inorganic mercury into methylmercury, and this process was affected by many environmental factors. The efficiency of mercury methylation reached 38% under anaerobic conditions with 1 mg x L(-1) HgCl2 and 0.9% salinity at 35 degrees C, pH 6.0. Increasing the initial HgCl2 concentration or salinity in an appropriate manner improved mercury methylation, but the concentration of methylmercury reduced when the concentrations of HgCl2 and salinity were too high. The efficiency of mercury methylation increased with the increasing temperature in range of 4-35 degrees C. Weakly acidic environment was more beneficial to mercury methylation than acidic, neutral or alkaline conditions. In addition, the efficiency of mercury methylation was also affected by humic acid and cysteine. Humic acid inhibited mercury methyaltion, whereas cysteine could improve the efficiency of mercury methylation. This study provided a direct evidence for mercury methylation mediated by iron-reducing bacteria in the natural aquatic ecosystem.

Apiose and mono-O-methyl sugars as minor constituents of the leaves of deciduous trees and various other species.

PubMed

Bacon, J S; Cheshire, M V

1971-09-01

1. Leaves of a number of species were hydrolysed with aqueous sulphuric acid and the resulting mixtures of sugars were fractionated by chromatography on activated charcoal. Paper chromatography of the fractions showed the presence in all the hydrolysates of minor constituents with R(F) values similar to or greater than those of the common hexoses and pentoses. 2. Two of these were identified as 2-O-methylxylose and 2-O-methylfucose. Estimates of the amounts present in whole leaves, and in fractions prepared from them, showed that they were associated with the hemicelluloses. 3. A third constituent was identified, by the formation of its di-isopropylidene derivative, as apiose. It also was associated chiefly with the hemicellulose fraction; none could be found in aqueous extracts from leaves of Tilia vulgaris, nor in aqueous extracts of Zostera marina, in which apiose is a major constituent of the water-insoluble polysaccharide. 4. A further constituent, after further purification by preparative paper chromatography, was tentatively identified, by gas-liquid chromatography of derivatives, as 3-O-methylgalactose, and was probably accompanied by small amounts of 4-O-methylgalactose. 5. These observations confirm the widespread occurrence of 2-O-methylxylose, 2-O-methylfucose and apiose, but 3-O-methylgalactose was hitherto known only in slippery-elm mucilage, and 4-O-methylgalactose in soil polysaccharides. Some experiments on the digestion of leaf hemicellulose fractions by snail crop-juice suggested that the mono-O-methyl sugars might confer resistance to enzymic degradation.

Apiose and mono-O-methyl sugars as minor constituents of the leaves of deciduous trees and various other species

PubMed Central

Bacon, J. S. D.; Cheshire, M. V.

1971-01-01

1. Leaves of a number of species were hydrolysed with aqueous sulphuric acid and the resulting mixtures of sugars were fractionated by chromatography on activated charcoal. Paper chromatography of the fractions showed the presence in all the hydrolysates of minor constituents with RF values similar to or greater than those of the common hexoses and pentoses. 2. Two of these were identified as 2-O-methylxylose and 2-O-methylfucose. Estimates of the amounts present in whole leaves, and in fractions prepared from them, showed that they were associated with the hemicelluloses. 3. A third constituent was identified, by the formation of its di-isopropylidene derivative, as apiose. It also was associated chiefly with the hemicellulose fraction; none could be found in aqueous extracts from leaves of Tilia vulgaris, nor in aqueous extracts of Zostera marina, in which apiose is a major constituent of the water-insoluble polysaccharide. 4. A further constituent, after further purification by preparative paper chromatography, was tentatively identified, by gas–liquid chromatography of derivatives, as 3-O-methylgalactose, and was probably accompanied by small amounts of 4-O-methylgalactose. 5. These observations confirm the widespread occurrence of 2-O-methylxylose, 2-O-methylfucose and apiose, but 3-O-methylgalactose was hitherto known only in slippery-elm mucilage, and 4-O-methylgalactose in soil polysaccharides. Some experiments on the digestion of leaf hemicellulose fractions by snail crop-juice suggested that the mono-O-methyl sugars might confer resistance to enzymic degradation. PMID:5135242

Structural characterization of saturated branched chain fatty acid methyl esters by collisional dissociation of molecular ions generated by electron ionization[S

PubMed Central

Ran-Ressler, Rinat R.; Lawrence, Peter; Brenna, J. Thomas

2012-01-01

Saturated branched chain fatty acids (BCFA) are present as complex mixtures in numerous biological samples. The traditional method for structure elucidation, electron ionization (EI) mass spectrometry, sometimes does not unambiguously enable assignment of branching in isomeric BCFA. Zirrolli and Murphy (Zirrolli , J. A. , and R. A. Murphy. 1993. Low-energy tandem mass spectrometry of the molecular ion derived from fatty acid methyl esters: a novel method for analysis of branched-chain fatty acids. J. Am. Soc. Mass Spectrom. 4: 223–229.) showed that the molecular ions of four BCFA methyl ester (BCFAME) yield highly characteristic fragments upon collisional dissociation using a triple quadrupole instrument. Here, we confirm and extend these results by analysis using a tabletop 3-D ion trap for activated molecular ion EI-MS/MS to 30 BCFAME. iso-BCFAME produces a prominent ion (30-100% of base peak) for [M-43] (M-C3H7), corresponding to the terminal isopropyl moiety in the original iso-BCFAME. Anteiso-FAME yield prominent ions (20-100% of base peak) corresponding to losses on both side of the methyl branch, [M-29] and [M-57], and tend to produce more prominent m/z 115 peaks corresponding to a cyclization product around the ester. Dimethyl and tetramethyl FAME, with branches separated by at least one methylene group, yield fragment on both sides of the sites of methyl branches that are more than 6 C away from the carboxyl carbon. EI-MS/MS yields uniquely specific ions that enable highly confident structural identification and quantification of BCFAME. PMID:22021637

Exercise-induced changes in enzymatic O-methylation of catecholestrogens by erythrocytes of eumenorrheic women.

PubMed

De Crée, C; Van Kranenburg, G; Geurten, P; Fujimura, Y; Keizer, H A

1997-12-01

The present study was designed to assess the effects of acute exercise and short-term intensive training on catechol-O-methyltransferase (COMT) activity. COMT inactivates catecholamines and converts primary catecholestrogens (CE) into their O-methylated form yielding the 2- (2-MeOE) and 4-methoxyestrogens (4-MeOE). Blood samples were obtained from 15 previously untrained eumenorrheic women (mean +/- SE, VO2max: 43.8 mL x kg-1 x min-1 +/- 0.6) before and after a 5-d intensive training period, at rest and during incremental exercise. COMT activity was determined in the erythrocytes (RBC-COMT) after incubation of blood lysate with primary CE. The formation of both 2- and 4-MeOE was significantly higher (P < 0.05) during the luteal (LPh) than during the follicular phase (FPh). The amount of 2-MeOE formed (FPh: 4.2 +/- 0.2%; LPh: 4.9 +/- 0.2%) was significantly greater than the produced amount of 4-MeOE (FPh: 1.4 +/- 0.1%; LPh: 1.5 +/- 0.1%) (P < 0.05). Both before and after training, incremental exercise did not significantly alter RBC-COMT activity although we observed a trend for RBC-COMT activity increasing proportionally with the exercise intensity. After a brief period of exhaustive training, during rest the formation of 2-MeOE (FPh: +16.7%, LPh: +15.7%) and 4-MeOE (FPh: +28.6%; LPh: +40%) was significantly (P < 0.05) increased. The results of the present study are consistent with earlier findings reporting increased plasma concentrations of O-methylated CE following training. It is concluded that RBC-COMT activity is increased by brief intensive training, but not by acute exercise. We speculate that an increase in COMT-catalyzed O-methylation of CE may indicate that less COMT is available to deactivate norepinephrine.

Synthesis, crystal structures, molecular docking, in vitro monoamine oxidase-B inhibitory activity of transition metal complexes with 2-{4-[bis (4-fluorophenyl)methyl]piperazin-1-yl} acetic acid

NASA Astrophysics Data System (ADS)

Yang, Dan-dan; Wang, Riu; Zhu, Jin-long; Cao, Qi-yue; Qin, Jie; Zhu, Hai-liang; Qian, Shao-song

2017-01-01

Three novel complexes, [Cu(L)2(H2O)](1), [Zn(L)2(H2O)2]·CH3OH·1.5H2O(2), and [Ni(L)2(H2O)1.8]·CH3OH·1.2H2O (3) (HL = 2-{4-[bis(4-fluorophenyl)methyl]pipera-zin-1-yl} acetic acid), were synthesized and structurally determined by single-crystal X-ray diffraction. Molecular docking study preliminarily revealed that complex 1 had potential Monoamine oxidase B inhibitory activity. All acquired compounds were tested against rat brain MAO-B in vitro. In accordance with the result of calculation, it showed complex 1 (IC50 = 1.85 ± 0.31 μM) have good inhibitory activity against MAO-B at the same micromolar concentrations with positive control Iproniazid Phosphate (IP, IC50 = 7.59 ± 1.17 μM). These results indicated that complex 1 was a potent MAO-B inhibitor.

Effect of Exogenous Abscisic Acid and Methyl Jasmonate on Anthocyanin Composition, Fatty Acids, and Volatile Compounds of Cabernet Sauvignon (Vitis vinifera L.) Grape Berries.

PubMed

Ju, Yan-Lun; Liu, Min; Zhao, Hui; Meng, Jiang-Fei; Fang, Yu-Lin

2016-10-12

The anthocyanin composition, fatty acids, and volatile aromas are important for Cabernet Sauvignon grape quality. This study evaluated the effect of exogenous abscisic acid (ABA) and methyl jasmonate (MeJA) on the anthocyanin composition, fatty acids, lipoxygenase activity, and the volatile compounds of Cabernet Sauvignon grape berries. Exogenous ABA and MeJA improved the content of total anthocyanins (TAC) and individual anthocyanins. Lipoxygenase (LOX) activity also increased after treatment. Furthermore, 16 fatty acids were detected. The linoleic acid concentration gradually increased with ABA concentration. The fatty acid content decreased with increasing MeJA concentration and then increased again, with the exception of linoleic acid. After exogenous ABA and MeJA treatment, the C6 aroma content increased significantly. Interestingly, the exogenous ABA and MeJA treatments improved mainly the content of 1-hexanol, hexanal, and 2-heptanol. These results provide insight into the effect of plant hormones on wine grapes, which is useful for grape quality improvement.

REACTIONS OF MERCAPTANS. I. FORMATION OF 2-METHYL-2-THIAZOLINE-4- CARBOXYLIC ACID FROM N-ACETYLCYSTEINE. II. A SPECTROPHOTOMETRIC METHOD FOR STUDY OF THE REACTION OF RADIATION-PROTECTIVE MERCAPTANS WITH ARYL DISULFIDES

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

Smith, H.A. Jr.

1962-08-01

I. Methyl 2-methyl-2-thiazoline-4-carboxylate was synthesized and converted to the corresponding acid. The behavior of the carboxythiazoline in various concentrations of mineral acids was studied spectrophotometrically. The cyclization of N-acetylcysteine to form a thiazoline-ring compound in concentrated mineral acids was also studied by this means. N-Acetylcysteine in concentrated mineral acid solutions yielded 2-methyl-2-thiazoline-4-carboxylic acid, which also was obtained by controlied hydrolysis of the corresponding methyl ester. Hydrolysis of methyl 2-methyl2-thiazoline-4-carboxylate, pK 3.05, in 0.1M sodium hydroxide yielded the corresponding carboxythiazoline in solution, pK 2.20 and 4.95. The carboxythiazoline was hydrolyzed very slowly in 7M hydrochloric acid, but the velocity of reactionmore » increased with decreasing acid concentration to a maximum at about pH 1.7; the products were N- and Sacetylcysteine, as well as cysteine and acetic acid. At acid concentrations below 0.2M, the last two products were formed slowly, and a pseudo-equilibrium could be established between thiazolinium ion, N-, and S-acetylcysteine. Equilibrium constants were determined. II. 4,4'-Dithiobis (benzenesulfonic acid) (I) and 4,4'-dithiobis(1-naphthalenesulfonic acid) (II) were synthesized from sulfanilic and naphthionic acids, respectively. The absorption spectra of I and II and of the corresponding mercaptans were determined. The thiol-disuifide interchange reactions were studied by spectrophotometric means for the reactions of cysteine with I and with II, and the equilibrium constants were determined. The systems had spectra very similar to those of the respective mixed disuifides with cysteine, and it was not possible to determine the concentrations from absorbancy measurements. On the other hand, the mercaptide ions had spectra different from the other species, with maxima at 285 and 348 m mu , respectively, and the concentrations of the corresponding mercaptans could

Changes in SCD gene DNA methylation after bariatric surgery in morbidly obese patients are associated with free fatty acids

PubMed Central

Morcillo, Sonsoles; Martín-Núñez, Gracia Mª; García-Serrano, Sara; Gutierrez-Repiso, Carolina; Rodriguez-Pacheco, Francisca; Valdes, Sergio; Gonzalo, Montserrat; Rojo-Martinez, Gemma; Moreno-Ruiz, Francisco J.; Rodriguez-Cañete, Alberto; Tinahones, Francisco; García-Fuentes, Eduardo

2017-01-01

Stearoyl CoA Desaturase-1 (SCD) is considered as playing an important role in the explanation of obesity. The aim of this study was to evaluate whether the DNA methylation SCD gene promoter is associated with the metabolic improvement in morbidly obese patients after bariatric surgery. The study included 120 subjects with morbid obesity who underwent a laparoscopic Roux-en Y gastric by-pass (RYGB) and a control group of 30 obese subjects with a similar body mass index (BMI) to that found in morbidly obese subjects six months after RYGB. Fasting blood samples were obtained before and at six months after RYGB. DNA methylation was measured by pyrosequencing technology. DNA methylation levels of the SCD gene promoter were lower in morbidly obese subjects before bariatric surgery but increased after RYGB to levels similar to those found in the control group. Changes of DNA methylation SCD gene were associated with the changes of free fatty acids levels (r = −0.442, p = 0.006) and HOMA-IR (r = −0.249, p = 0.035) after surgery. RYGB produces an increase in the low SCD methylation promoter levels found in morbidly obese subjects. This change of SCD methylation levels is associated with changes in FFA and HOMA-IR. PMID:28393901

Fatty acid methyl ester profiles of bat wing surface lipids.

PubMed

Pannkuk, Evan L; Fuller, Nathan W; Moore, Patrick R; Gilmore, David F; Savary, Brett J; Risch, Thomas S

2014-11-01

Sebocytes are specialized epithelial cells that rupture to secrete sebaceous lipids (sebum) across the mammalian integument. Sebum protects the integument from UV radiation, and maintains host microbial communities among other functions. Native glandular sebum is composed primarily of triacylglycerides (TAG) and wax esters (WE). Upon secretion (mature sebum), these lipids combine with minor cellular membrane components comprising total surface lipids. TAG and WE are further cleaved to smaller molecules through oxidation or host enzymatic digestion, resulting in a complex mixture of glycerolipids (e.g., TAG), sterols, unesterified fatty acids (FFA), WE, cholesteryl esters, and squalene comprising surface lipid. We are interested if fatty acid methyl ester (FAME) profiling of bat surface lipid could predict species specificity to the cutaneous fungal disease, white nose syndrome (WNS). We collected sebaceous secretions from 13 bat spp. using Sebutape(®) and converted them to FAME with an acid catalyzed transesterification. We found that Sebutape(®) adhesive patches removed ~6× more total lipid than Sebutape(®) indicator strips. Juvenile eastern red bats (Lasiurus borealis) had significantly higher 18:1 than adults, but 14:0, 16:1, and 20:0 were higher in adults. FAME profiles among several bat species were similar. We concluded that bat surface lipid FAME profiling does not provide a robust model predicting species susceptibility to WNS. However, these results provide baseline data that can be used for lipid roles in future ecological studies, such as life history, diet, or migration.

Probing the active center of benzaldehyde lyase with substitutions and the pseudo-substrate analog benzoylphosphonic acid methyl ester

PubMed Central

Brandt, Gabriel S.; Nemeria, Natalia; Chakraborty, Sumit; McLeish, Michael J.; Yep, Alejandra; Kenyon, George L.; Petsko, Gregory A.; Jordan, Frank; Ringe, Dagmar

2009-01-01

Benzaldehyde lyase (BAL) catalyzes the reversible cleavage of (R)-benzoin to benzaldehyde utilizing thiamin diphosphate and Mg2+ as cofactors. The enzyme is important for the chemoenzymatic synthesis of a wide range of compounds via its carboligation reaction mechanism. In addition to its principal functions, BAL can slowly decarboxylate aromatic amino acids such as benzoylformic acid. It is also intriguing mechanistically due to the paucity of acid-base residues at the active center that can participate in proton transfer steps thought to be necessary for these type of reactions. Here methyl benzoylphosphonate, an excellent electrostatic analog of benzoylformic acid, is used to probe the mechanism of benzaldehyde lyase. The structure of benzaldehyde lyase in its covalent complex with methyl benzoylphosphonate was determined to 2.49 Å (PDB ID: 3D7K) and represents the first structure of this enzyme with a compound bound in the active site. No large structural reorganization was detected compared to the complex of the enzyme with thiamin diphosphate. The configuration of the predecarboxylation thiamin-bound intermediate was clarified by the structure. Both spectroscopic and X-ray structural studies are consistent with inhibition resulting from the binding of MBP to the thiamin diphosphate in the active centers. We also delineated the role of His29 (the sole potential acid-base catalyst in the active site other than the highly conserved Glu50) and Trp163 in cofactor activation and catalysis by benzaldehyde lyase. PMID:18570438

Preparation of fatty acid methyl esters from hazelnut, high-oleic peanut and walnut oils and evaluation as biodiesel

USDA-ARS?s Scientific Manuscript database

Hazelnut, walnut and high-oleic peanut oils were converted into fatty acid methyl esters using catalytic sodium methoxide and evaluated as potential biodiesel fuels. These feedstocks were of interest due to their adaptability to marginal lands and their lipid production potentials (780-1780 L ha-1 y...

40 CFR 180.479 - Halosulfuron-methyl; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... residues of the herbicide halosulfuron-methyl, methyl 3-chloro-5-[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl] amino] sulfonyl]-1-methyl-1H-pyrazole-4-carboxylate, and its metabolites and degradates in or on...-sulfamoylpyrazole-4-carboxylic acid, expressed as the stoichiometric equivalent of halosulfuron-methyl, in or on the...

Antibacterial and antifungal efficacy of fatty acid methyl esters from the leaves of Sesuvium portulacastrum L.

PubMed

Chandrasekaran, M; Senthilkumar, A; Venkatesalu, V

2011-07-01

The fatty acid methyl esters (FAME extract) from Sesuvium (S.) portulacastrum was studied for its fatty acid composition and antimicrobial activity against human pathogenic microorganisms. The gas chromatographic analysis of FAME extract revealed the presence of palmitic acid with the highest relative percentage (31.18%), followed by oleic acid (21.15%), linolenic acid (14.18%) linoleic acid (10.63%), myristic acid (6.91%) and behenic acid (2.42%). The saturated fatty acids were higher than the unsaturated fatty acids. FAME extract showed the highest antibacterial and anticandidal activities and moderate antifungal activity against the tested microorganisms. The highest mean zone of inhibition (16.3 mm) and the lowest MIC (0.25 mg/ml) and MBC (0.5 mg/ml) values were recorded against Bacillus subtilis. The lowest mean zone of inhibition (8.8 mm) and the highest MIC (8 mg/ml) and MFC (16 mg/ml) values were recorded against Aspergillus fumigatus and Aspergillus niger. The results of the present study justify the use of S. portulacastrum in traditional medicine and the FAME extract can be used as a potential antimicrobial agent against the tested human pathogenic microorganisms.

Why Do Enolate Anions Favor O-Alkylation over C-Alkylation in the Gas Phase? The Roles of Resonance and Inductive Effects in the Gas-Phase SN2 Reaction between the Acetaldehyde Enolate Anion and Methyl Fluoride.

PubMed

Seitz, Christian G; Zhang, Huaiyu; Mo, Yirong; Karty, Joel M

2016-05-06

Contributions by resonance and inductive effects toward the net activation barrier were determined computationally for the gas-phase SN2 reaction between the acetaldehyde enolate anion and methyl fluoride, for both O-methylation and C-methylation, in order to understand why this reaction favors O-methylation. With the use of the vinylogue extrapolation methodology, resonance effects were determined to contribute toward increasing the size of the barrier by about 9.5 kcal/mol for O-methylation and by about 21.2 kcal/mol for C-methylation. Inductive effects were determined to contribute toward increasing the size of the barrier by about 1.7 kcal/mol for O-methylation and 4.2 kcal/mol for C-methylation. Employing our block-localized wave function methodology, we determined the contributions by resonance to be 12.8 kcal/mol for O-methylation and 22.3 kcal/mol for C-methylation. Thus, whereas inductive effects have significant contributions, resonance is the dominant factor that leads to O-methylation being favored. More specifically, resonance serves to increase the size the barrier for C-methylation significantly more than it does for O-methylation.

Production of FAME biodiesel in E. coli by direct methylation with an insect enzyme.

PubMed

Sherkhanov, Saken; Korman, Tyler P; Clarke, Steven G; Bowie, James U

2016-04-07

Most biodiesel currently in use consists of fatty acid methyl esters (FAMEs) produced by transesterification of plant oils with methanol. To reduce competition with food supplies, it would be desirable to directly produce biodiesel in microorganisms. To date, the most effective pathway for the production of biodiesel in bacteria yields fatty acid ethyl esters (FAEEs) at up to ~1.5 g/L. A much simpler route to biodiesel produces FAMEs by direct S-adenosyl-L-methionine (SAM) dependent methylation of free fatty acids, but FAME production by this route has been limited to only ~16 mg/L. Here we employ an alternative, broad spectrum methyltransferase, Drosophila melanogaster Juvenile Hormone Acid O-Methyltransferase (DmJHAMT). By introducing DmJHAMT in E. coli engineered to produce medium chain fatty acids and overproduce SAM, we obtain medium chain FAMEs at titers of 0.56 g/L, a 35-fold increase over titers previously achieved. Although considerable improvements will be needed for viable bacterial production of FAMEs and FAEEs for biofuels, it may be easier to optimize and transport the FAME production pathway to other microorganisms because it involves fewer enzymes.

Production of FAME biodiesel in E. coli by direct methylation with an insect enzyme

DOE PAGES

Sherkhanov, Saken; Korman, Tyler P.; Clarke, Steven G.; ...

2016-04-07

Here, most biodiesel currently in use consists of fatty acid methyl esters (FAMEs) produced by transesterification of plant oils with methanol. To reduce competition with food supplies, it would be desirable to directly produce biodiesel in microorganisms. To date, the most effective pathway for the production of biodiesel in bacteria yields fatty acid ethyl esters (FAEEs) at up to ~1.5 g/L. A much simpler route to biodiesel produces FAMEs by direct S-adenosyl-L-methionine (SAM) dependent methylation of free fatty acids, but FAME production by this route has been limited to only ~16 mg/L. Here we employ an alternative, broad spectrum methyltransferase,more » Drosophila melanogaster Juvenile Hormone Acid O-Methyltransferase ( DmJHAMT). By introducing DmJHAMT in E. coli engineered to produce medium chain fatty acids and overproduce SAM, we obtain medium chain FAMEs at titers of 0.56 g/L, a 35-fold increase over titers previously achieved. Although considerable improvements will be needed for viable bacterial production of FAMEs and FAEEs for biofuels, it may be easier to optimize and transport the FAME production pathway to other microorganisms because it involves fewer enzymes.« less

Production of FAME biodiesel in E. coli by direct methylation with an insect enzyme

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

Sherkhanov, Saken; Korman, Tyler P.; Clarke, Steven G.

Here, most biodiesel currently in use consists of fatty acid methyl esters (FAMEs) produced by transesterification of plant oils with methanol. To reduce competition with food supplies, it would be desirable to directly produce biodiesel in microorganisms. To date, the most effective pathway for the production of biodiesel in bacteria yields fatty acid ethyl esters (FAEEs) at up to ~1.5 g/L. A much simpler route to biodiesel produces FAMEs by direct S-adenosyl-L-methionine (SAM) dependent methylation of free fatty acids, but FAME production by this route has been limited to only ~16 mg/L. Here we employ an alternative, broad spectrum methyltransferase,more » Drosophila melanogaster Juvenile Hormone Acid O-Methyltransferase ( DmJHAMT). By introducing DmJHAMT in E. coli engineered to produce medium chain fatty acids and overproduce SAM, we obtain medium chain FAMEs at titers of 0.56 g/L, a 35-fold increase over titers previously achieved. Although considerable improvements will be needed for viable bacterial production of FAMEs and FAEEs for biofuels, it may be easier to optimize and transport the FAME production pathway to other microorganisms because it involves fewer enzymes.« less

Production of FAME biodiesel in E. coli by direct methylation with an insect enzyme

PubMed Central

Sherkhanov, Saken; Korman, Tyler P.; Clarke, Steven G; Bowie, James U.

2016-01-01

Most biodiesel currently in use consists of fatty acid methyl esters (FAMEs) produced by transesterification of plant oils with methanol. To reduce competition with food supplies, it would be desirable to directly produce biodiesel in microorganisms. To date, the most effective pathway for the production of biodiesel in bacteria yields fatty acid ethyl esters (FAEEs) at up to ~1.5 g/L. A much simpler route to biodiesel produces FAMEs by direct S-adenosyl-L-methionine (SAM) dependent methylation of free fatty acids, but FAME production by this route has been limited to only ~16 mg/L. Here we employ an alternative, broad spectrum methyltransferase, Drosophila melanogaster Juvenile Hormone Acid O-Methyltransferase (DmJHAMT). By introducing DmJHAMT in E. coli engineered to produce medium chain fatty acids and overproduce SAM, we obtain medium chain FAMEs at titers of 0.56 g/L, a 35-fold increase over titers previously achieved. Although considerable improvements will be needed for viable bacterial production of FAMEs and FAEEs for biofuels, it may be easier to optimize and transport the FAME production pathway to other microorganisms because it involves fewer enzymes. PMID:27053100

40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric acid (H3BO3).

Code of Federal Regulations, 2012 CFR

2012-07-01

...-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric...

40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric acid (H3BO3).

Code of Federal Regulations, 2010 CFR

2010-07-01

...-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric...

40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric acid (H3BO3).

Code of Federal Regulations, 2011 CFR

2011-07-01

...-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric...