Methylation of ribonucleic acid by the carcinogens dimethyl sulphate, N-methyl-N-nitrosourea and N-methyl-N′-nitro-N-nitrosoguanidine. Comparisons of chemical analyses at the nucleoside and base levels

PubMed Central

Lawley, P. D.; Shah, S. A.

1972-01-01

1. The following methods for hydrolysis of methyl-14C-labelled RNA, and for chromatographic isolation and determination of the products, were investigated: enzymic digestion to nucleosides at pH6 or 8; alkaline hydrolysis and conversion into nucleosides; hydrolysis by acid to pyrimidine nucleotides and purine bases, or completely to bases; chromatography on Dowex 50 (NH4+ form) at pH6 or 8.9, or on Dowex 50 (H+ form), or on Sephadex G-10. 2. The suitability of the various methods for determination of methylation products was assessed. The principal product, 7-methylguanosine, was unstable under the conditions used for determinations of nucleosides. 3- and 7-Methyladenine and 3- and 7-methylguanine are best determined as bases; 1-methyladenine and 3-methylcytosine can be isolated as either nucleosides or bases; O6-methylguanine is unstable under the acid hydrolysis conditions used and can be determined as the nucleoside; 3-methyluracil was detected, but may be derived from methylation of the ionized form of uracil. 3. Differences between the patterns of methylation of RNA and homopolyribonucleotides by the N-methyl-N-nitroso compounds and dimethyl sulphate were found: the nitroso compounds were able to methylate O-6 of guanine, were relatively more reactive at N-7 of adenine and probably at N-3 of guanine, but less reactive at N-1 of adenine, N-3 of cytosine and probably at N-3 of uridine. They probably reacted more with the ribose–phosphate chain, but no products from this were identified. 4. The possible influences of these differences on biological action of the methylating agents is discussed. Nitroso compounds may differ principally in their ability to induce miscoding in the Watson–Crick sense by reaction at O-6 of guanine. Both types of agent may induce miscoding to a lesser extent through methylation at N-3 of guanine; both can methylate N atoms, presumably preventing Watson–Crick hydrogen-bonding. N-Methyl-N-nitrosourea can degrade RNA, possibly

The degree of microRNA-34b/c methylation in serum-circulating DNA is associated with malignant pleural mesothelioma.

PubMed

Muraoka, Takayuki; Soh, Junichi; Toyooka, Shinichi; Aoe, Keisuke; Fujimoto, Nobukazu; Hashida, Shinsuke; Maki, Yuho; Tanaka, Norimitsu; Shien, Kazuhiko; Furukawa, Masashi; Yamamoto, Hiromasa; Asano, Hiroaki; Tsukuda, Kazunori; Kishimoto, Takumi; Otsuki, Takemi; Miyoshi, Shinichiro

2013-12-01

Malignant pleural mesothelioma (MPM) is an aggressive tumor with a poor prognosis. microRNA-34b/c (miR-34b/c), which plays an important role in the pathogenesis of MPM, is frequently downregulated by DNA methylation in approximately 90% of MPM cases. In this study, we estimated the degree of miR-34b/c methylation in serum-circulating DNA using a digital methylation specific PCR assay (MSP). A real-time MSP assay was performed using the SYBR Green method. The melting temperature (Tm) of each PCR product was examined using a melting curve analysis. For a digital MSP assay, 40 wells were analyzed per sample. A total of 110 serum samples from 48 MPM cases, 21 benign asbestos pleurisy (BAP) cases, and 41 healthy volunteers (HVs) were examined. Positive range of Tm value for miR-34b/c methylation was defined as 77.71-78.79 °C which was the mean ± 3 standard deviations of 40 wells of a positive control. The number of miR-34b/c methylated wells was counted per sample according to this criterion. The number of miR-34b/c methylated wells in MPM cases was significantly higher than that in BAP cases (P=0.03) or HVs (P<0.001). Advanced MPM cases tended to have higher number of miR-34b/c methylated wells than early MPM cases. Receiver-operating characteristic (ROC) curve analysis revealed that three number of miR-34b/c methylated wells per sample was the best cut-off of positivity of MPM with a 67% of sensitivity and a 77% specificity for prediction. The area under the ROC curve was 0.77. Our digital MSP assay can quantify miR-34b/c methylation in serum-circulating DNA. The degree of miR-34b/c methylation in serum-circulating DNA is associated with MPM, suggesting that this approach might be useful for the establishment of a new detection system for MPM. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Novel pyrrolinones as N-methyl-D-aspartate receptor antagonists.

PubMed

Poschenrieder, Hermann; Stachel, Hans-Dietrich; Höfner, Georg; Mayer, Peter

2005-04-01

A series of oximes, deriving from 2-arylidene-pyrroline-3,4-diones (7, 8, 22, 23) has been prepared. The presence of tautomers in their solutions has been established by spectroscopic means. The compounds reacted with diazomethane chiefly by N-methylation forming nitrones (10, 11). The analogously prepared 2-arylidene-4-nitropyrrolin-3-ones (12, 13, 24, 25), formally derived from nitrotetramic acids, yielded nitronic acid esters (14, 15, 26) upon reaction with diazomethane. The structures were elucidated by spectral evidence and-in the case of compounds 10 and 20b-by X-ray diffraction analysis. The binding affinity of some of the new compounds toward the N-methyl-d-aspartate (NMDA) (glycine site) receptor has been measured thus providing the basis for further structure-activity relationship studies. Oxime 8b showed the highest binding potency (Ki= 9.2 microM).

40 CFR 721.4080 - MNNG (N-methyl-N′-nitro-N-nitrosoguanidine).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false MNNG (N-methyl-Nâ²-nitro-N... Specific Chemical Substances § 721.4080 MNNG (N-methyl-N′-nitro-N-nitrosoguanidine). (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance MNNG (N-methyl-N′-nitro-N...

40 CFR 721.4080 - MNNG (N-methyl-N′-nitro-N-nitrosoguanidine).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false MNNG (N-methyl-Nâ²-nitro-N... Specific Chemical Substances § 721.4080 MNNG (N-methyl-N′-nitro-N-nitrosoguanidine). (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance MNNG (N-methyl-N′-nitro-N...

Isotopic characterisation of 3,4-methylenedioxyamphetamine and 3,4-methylenedioxymethylamphetamine (ecstasy).

PubMed

Carter, James F; Titterton, a Emma L; Murray, Martin; Sleeman, Richard

2002-06-01

Combined delta2H, delta13C and delta15N isotopic analysis of MDA and MDMA extracted from seized "ecstasy" tablets provides an isotopic "fingerprint" of the active ingredient allowing individual tablets to be linked to a common batch. Correlating these data with 2H NMR analysis of the extracts has the potential to study both the natural precursor materials and synthetic pathways used in the preparation of MDA and N-substituted homologues.

N-METHYL GROUPS IN BACTERIAL LIPIDS

PubMed Central

Goldfine, Howard; Ellis, Martha E.

1964-01-01

Goldfine, Howard (Harvard Medical School, Boston, Mass.), and Martha E. Ellis. N-methyl groups in bacterial lipids. J. Bacteriol. 87:8–15. 1964.—The ability of bacteria to synthesize lecithin was examined by measuring the incorporation of the methyl group of methionine into the water-soluble moieties obtained on acid hydrolysis of bacterial lipids. Of 21 species examined, mostly of the order Eubacteriales, only 2, Agrobacterium radiobacter and A. rhizogenes, incorporated the methyl group of methionine into lipid-bound choline. Evidence was also obtained for the formation of lipid-bound N-methylethanolamine and N,N′-dimethylethanolamine in these two organisms. Two other species, Clostridium butyricum and Proteus vulgaris, incorporated the methyl group of methionine into lipid-bound N-methylethanolamine, but did not appear to be able to further methylate these lipids to form lecithin. The results of this study lend further strength to the generalization that bacteria, with the exception of the genus Agrobacterium, are unable to synthesize lecithin. PMID:14102879

Direct comparison of (+/-) 3,4-methylenedioxymethamphetamine ("ecstasy") disposition and metabolism in squirrel monkeys and humans.

PubMed

Mueller, Melanie; Kolbrich, Erin A; Peters, Frank T; Maurer, Hans H; McCann, Una D; Huestis, Marilyn A; Ricaurte, George A

2009-06-01

The present study compared the disposition and metabolism of the recreational drug (+/-) 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") in squirrel monkeys and humans because the squirrel monkey has been extensively studied for MDMA neurotoxicity. A newly developed liquid chromatography-mass spectrometric procedure for simultaneous measurement of MDMA, 3,4-dihydroxymethamphetamine, 4-hydroxy-3-methoxymethamphetamine, and 3,4-methylenedioxyamphetamine was employed. In both humans and squirrel monkeys, a within-subject design permitted testing of different doses in the same subjects. Humans and squirrel monkeys were found to metabolize MDMA in similar, but not identical, pathways and proportions. In particular, amounts of 3,4-dihydroxymethamphetamine (after conjugate cleavage) and 3,4-methylenedioxyamphetamine were similar in the 2 species, but formation of 4-hydroxy-3-methoxymethamphetamine was greater in squirrel monkeys than in humans. Both species demonstrated nonlinear MDMA pharmacokinetics at comparable plasma MDMA concentrations (125-150 ng/mL and above). The elimination half-life of MDMA was considerably shorter in squirrel monkeys than in humans (2-3 versus 6-9 hours). In both species, there was substantial individual variability. These results suggest that the squirrel monkey may be a useful model for predicting outcomes of MDMA exposure in humans, although this will also depend on the degree to which MDMA pharmacodynamics in the squirrel monkey parallels that in humans.

Inhibition of protein synthesis by N-methyl-N-nitrosourea in vivo

PubMed Central

Kleihues, P.; Magee, P. N.

1973-01-01

1. The intraperitoneal injection of N-methyl-N-nitrosourea (100mg/kg) caused a partial inhibition of protein synthesis in several organs of the rat, the maximum effect occurring after 2–3h. 2. In the liver the inhibition of protein synthesis was paralleled by a marked disaggregation of polyribosomes and an increase in ribosome monomers and ribosomal subunits. No significant breakdown of polyribosomes was found in adult rat brains although N-methyl-N-nitrosourea inhibited cerebral and hepatic protein synthesis to a similar extent. In weanling rats N-methyl-N-nitrosourea caused a shift in the cerebral polyribosome profile similar to but less marked than that in rat liver. 3. Reaction of polyribosomal RNA with N-[14C]methyl-N-nitrosourea in vitro did not lead to a disaggregation of polyribosomes although the amounts of 7-methylguanine produced were up to twenty times higher than those found after administration of sublethal doses in vivo. 4. It was concluded that changes in the polyribosome profile induced by N-methyl-N-nitrosourea may reflect the mechanism of inhibition of protein synthesis rather than being a direct consequence of the methylation of polyribosomal mRNA. PMID:4774397

The expression of hematopoietic progenitor cell antigen CD34 is regulated by DNA methylation in a site-dependent manner in gastrointestinal stromal tumours.

PubMed

Bure, Irina; Braun, Alexander; Kayser, Claudia; Geddert, Helene; Schaefer, Inga-Marie; Cameron, Silke; Ghadimi, Michael B; Ströbel, Philipp; Werner, Martin; Hartmann, Arndt; Wiemann, Stefan; Agaimy, Abbas; Haller, Florian; Moskalev, Evgeny A

2017-12-01

The anatomic site-dependent expression of hematopoietic progenitor cell antigen CD34 is a feature of gastrointestinal stromal tumours (GISTs). The basis for the differential CD34 expression is only incompletely understood. This study aimed at understanding the regulation of CD34 in GISTs and clarification of its site-dependent expression. Two sample sets of primary GISTs were interrogated including 52 fresh-frozen and 134 paraffin-embedded and formalin-fixed specimens. DNA methylation analysis was performed by HumanMethylation450 BeadChip array in three cell lines derived from gastric and intestinal GISTs, and differentially methylated CpG sites were established upstream of CD34. The methylation degree was further quantified by pyrosequencing, and inverse correlation with CD34 mRNA and protein abundance was revealed. The gene's expression could be activated upon induction of DNA hypomethylation with 5-aza-2'-deoxycytidine in GIST-T1 cells. In patient samples, a strong inverse correlation of DNA methylation degree with immunohistochemically evaluated CD34 expression was documented. Both CD34 expression and DNA methylation levels were specific to the tumours' anatomic location and mutation status. A constant decrease in methylation levels was observed ranging from almost 100% hypermethylation in intestinal GISTs from duodenum to hypomethylation in rectum. CD34 was heavily methylated in gastric PDGFRA-mutant GISTs in comparison to hypomethylated KIT-mutant counterparts. Next to CD34 hypermethylation, miR-665 was predicted and experimentally confirmed to target CD34 mRNA in GIST-T1 cells. Our results suggest that CD34 expression in GISTs may undergo a complex control by DNA methylation and miR-665. Differential methylation and expression of CD34 in GISTs along the gastrointestinal tract axis and in tumours that harbour different gain-of-function mutations suggest the origin from different cell populations in the gastrointestinal tract. © 2017 UICC.

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.

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

N(4)-Methyl-N(4)-(2-methylphenyl)-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine-ethanol-hydrazine (1/0.865/0.135): hydrogen-bonded ribbons containing four independent ring types.

PubMed

Trilleras, Jorge; Quiroga, Jairo; Cobo, Justo; Glidewell, Christopher

2009-06-01

N(4)-Methyl-N(4)-(2-methylphenyl)-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine crystallizes from ethanol as a mixed solvate, C(13)H(14)N(6).0.865C(2)H(6)O.0.135N(2)H(4), (I), where the hydrazine has been carried through from the initial preparation. Within the heterocyclic component, the 2-methylphenyl substituent is disordered over two sets of sites. There is an intramolecular C-H...pi(arene) hydrogen bond, which may control the molecular conformation of the heterocycle. The heterocyclic molecules are linked by two independent N-H...N hydrogen bonds in a chain containing two types of R(2)(2)(8) ring. The ethanol component is linked to this chain by a combination of O-H...N and N-H...O hydrogen bonds and the hydrazine component by two N-H...N hydrogen bonds, so generating two R(3)(3)(9) rings and thus forming a ribbon containing four distinct ring types.

40 CFR 721.4925 - Methyl n-butyl ketone.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Methyl n-butyl ketone. 721.4925... Substances § 721.4925 Methyl n-butyl ketone. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance methyl n-butyl ketone, CAS Number 591-78-6, is subject to reporting...

40 CFR 721.4925 - Methyl n-butyl ketone.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Methyl n-butyl ketone. 721.4925... Substances § 721.4925 Methyl n-butyl ketone. (a) Chemical substance and significant new use subject to reporting. (1) The chemical substance methyl n-butyl ketone, CAS Number 591-78-6, is subject to reporting...

Reinforcing effects of methylenedioxy amphetamine congeners in rhesus monkeys: are intravenous self-administration experiments relevant to MDMA neurotoxicity?

PubMed

Fantegrossi, William E

2007-01-01

Many animal models relevant to the persistent effects of drugs of abuse necessitate the application of interspecies dose scaling procedures to approximate drug administration regimens in humans, but drug self-administration procedures differ in that they allow animal subjects to control their own drug intake. This report reviews the reinforcing effects of 3,4-methylenedioxymethamphetamine (MDMA), its enantiomers, and several structural analogs in rhesus monkeys, paying particular attention to the pharmacological mechanisms of such reinforcing effects, the development of structure activity relationships among these compounds, the stability of MDMA self-administration behavior over time, and the persistent effects of self-administered MDMA on monoamines. The methylenedioxy amphetamine congeners MDMA, 3,4-methylenedioxyamphetamine, N-ethyl-3,4-methylenedioxyamphetamine, and N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine function as reinforcers in rhesus monkeys, maintaining self-administration behavior greater than that engendered by contingent saline but less than that engendered by traditional psychostimulants. These findings are remarkable as structurally distinct serotonergic hallucinogen-like drugs do not maintain reliable self-administration in laboratory animals. During prolonged MDMA self-administration, MDMA-maintained responding progressively weakens, and MDMA eventually fails to maintain significant self-administration. The neurochemical correlates of this effect have not yet been identified. Procedures in which MDMA and related compounds are self-administered can be established in rhesus monkeys. These techniques can be used to engender contingent MDMA exposure without resorting to controversial methods of interspecies dose scaling. As such, further application of self-administration methods may provide important new insights into the persistent effects of MDMA on brain and behavior in nonhuman primates.

Anhydrous versus hydrated N4-substituted 1H-pyrazolo[3,4-d]pyrimidine-4,6-diamines: hydrogen bonding in two and three dimensions.

PubMed

Trilleras, Jorge; Quiroga, Jairo; Cobo, Justo; Marchal, Antonio; Nogueras, Manuel; Low, John N; Glidewell, Christopher

2008-10-01

Ten new N(4)-substituted 1H-pyrazolo[3,4-d]pyrimidine-4,6-diamines have been synthesized and the structures of nine of them are reported here, falling into two clear groups, those which are stoichiometric hydrates and those which crystallize in solvent-free forms. In each of N(4)-methyl-N(4)-phenyl-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine, C(12)H(12)N(6) (I), N(4)-cyclohexyl-N(4)-methyl-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine, C(12)H(18)N(6) (II), and N(4)-(3-chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine, C(11)H(9)ClN(6) (III), the molecules are linked into hydrogen-bonded sheets. The molecules of 2-{4-(6-amino-1H-pyrazolo[3,4-d]pyrimidin-4-yl)piperazin-1-yl}ethanol, C(11)H(17)N(7)O (IV), are linked into a three-dimensional framework, while the structure of N(4)-methyl-N(4)-(4-methylphenyl)-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine monohydrate, C(13)H(14)N(6) x H(2)O (V), is only two-dimensional despite the presence of five independent hydrogen bonds. The stoichiometric hemihydrates N(4)-ethyl-N(4)-phenyl-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine hemihydrate, C(13)H(14)N(6) x 0.5 H(2)O (VI) and N(4)-(4-methoxyphenyl)-N(4)-methyl-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine hemihydrate, C(13)H(14)N(6)O x 0.5 H(2)O (VII), exhibit remarkably similar sheet structures, despite different space groups and Z' values, Z' = 0.5 in C2/c for (VI) and Z' = 1 in P1 for (VII). N(4)-4-Benzyl-N(4)-phenyl-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine monohydrate, C(18)H(16)N(6) x H(2)O (VIII), crystallizes with Z' = 2 in P2(1)/n, and the four independent molecular components are linked into sheets by a total of 11 intermolecular hydrogen bonds. The sheet structure in {4-(pyrrolidin-1-yl)-1H-pyrazolo[3,4-d]pyrimidine-6-amine} ethanol hemisolvate hemihydrate, C(9)H(12)N(6).0.5C(2)H(6)O x 0.5 H(2)O (IX), is built from the pyrimidine and water components only; it contains eight independent hydrogen bonds, and it very closely mimics the sheets in (VI) and (VII); the ethanol molecules are

Polyacrylonitrile Nanofiber-Based Quartz Crystal Microbalance for Sensitive Detection of Safrole

PubMed Central

Julian, Trisna; Hidayat, Shidiq Nur; Suyono, Eko Agus

2018-01-01

Safrole is the main precursor for producing the amphetamine-type stimulant (ATS) drug, N-methyl-3,4-methylenedioxyamphetamine (MDMA), also known as ecstasy. We devise a polyacrylonitrile (PAN) nanofiber-based quartz crystal microbalance (QCM) for detecting safrole. The PAN nanofibers were fabricated by direct electrospinning to modify the QCM chips. The PAN nanofiber on the QCM chips has a diameter of 240 ± 10 nm. The sensing of safrole by QCM modified with PAN nanofiber shows good reversibility and an apparent sensitivity of 4.6 Hz·L/mg. The proposed method is simple, inexpensive, and convenient for detecting safrole, and can be an alternative to conventional instrumental analytical methods for general volatile compounds. PMID:29642565

Phenylethylamine N-methylation by human brain preparations

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

Mosnaim, A.D.; Callaghan, O.H.; Wolf, M.E.

Alterations in the brain metabolism of biogenic amines has been postulated to play a role in the pathophysiology of several psychiatric disorders. There is some evidence suggesting schizogenic properties for some abnormal neuroamine methylated derivatives. The authors now report that postmortem human brain preparations, obtained from the putamen and thalamus, convert phenylethylamine (PEA) to its behaviorally active derivative N-methyl PEA, a reaction which is carried out by the 100,000 xg supernatant (in presence of 1 x 10 /sup -5/M pargyline) and enhanced by the addition of NADPH. PEA N-methylation occurred in schizophrenics as well as in sex and age matchedmore » controls. The formation of increased amounts of (/sup 3/H-) or (/sup 14/C-) N-methyl PEA when incubating either cold amine and /sup 3/H-SAM or 1-/sup 14/C PEA and cold SAM, respectively, indicates that SAM is a methyl group donor in this reaction. They will discuss the physiological and pharmacological implications of these results.« less

Serotonergic neurotoxic metabolites of ecstasy identified in rat brain.

PubMed

Jones, Douglas C; Duvauchelle, Christine; Ikegami, Aiko; Olsen, Christopher M; Lau, Serrine S; de la Torre, Rafael; Monks, Terrence J

2005-04-01

The selective serotonergic neurotoxicity of 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) depends on their systemic metabolism. We have recently shown that inhibition of brain endothelial cell gamma-glutamyl transpeptidase (gamma-GT) potentiates the neurotoxicity of both MDMA and MDA, indicating that metabolites that are substrates for this enzyme contribute to the neurotoxicity. Consistent with this view, glutathione (GSH) and N-acetylcysteine conjugates of alpha-methyl dopamine (alpha-MeDA) are selective neurotoxicants. However, neurotoxic metabolites of MDMA or MDA have yet to be identified in brain. Using in vivo microdialysis coupled to liquid chromatography-tandem mass spectroscopy and a high-performance liquid chromatography-coulometric electrode array system, we now show that GSH and N-acetylcysteine conjugates of N-methyl-alpha-MeDA are present in the striatum of rats administered MDMA by subcutaneous injection. Moreover, inhibition of gamma-GT with acivicin increases the concentration of GSH and N-acetylcysteine conjugates of N-methyl-alpha-MeDA in brain dialysate, and there is a direct correlation between the concentrations of metabolites in dialysate and the extent of neurotoxicity, measured by decreases in serotonin (5-HT) and 5-hydroxyindole acetic (5-HIAA) levels. Importantly, the effects of acivicin are independent of MDMA-induced hyperthermia, since acivicin-mediated potentiation of MDMA neurotoxicity occurs in the context of acivicin-mediated decreases in body temperature. Finally, we have synthesized 5-(N-acetylcystein-S-yl)-N-methyl-alpha-MeDA and established that it is a relatively potent serotonergic neurotoxicant. Together, the data support the contention that MDMA-mediated serotonergic neurotoxicity is mediated by the systemic formation of GSH and N-acetylcysteine conjugates of N-methyl-alpha-MeDA (and alpha-MeDA). The mechanisms by which such metabolites access the brain and produce selective

GC-MS studies on the regioisomeric methoxy-methyl-phenethylamines related to MDEA, MDMMA, and MBDB.

PubMed

Thigpen, Ashley; Awad, Tamer; Deruiter, Jack; Clark, C Randall

2008-01-01

Three regioisomeric 3,4-methylenedioxyphenethylamines having the same molecular weight and major mass spectral fragments of equal mass have been reported as drugs of abuse in forensic studies in recent years. These compounds are 3,4-methylenedioxy-N-ethylamphetamine (MDEA), 3,4-methylenedioxy-N-N-dimethylamphetamine (MDMMA), and N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine (MBDB). The mass spectra of the regioisomers (4-methoxy-3-methyl and 4-methoxy-2-methyl-phenethylamines) are essentially equivalent to the three compounds reported as drugs of abuse. This project focused on the synthesis, mass spectral characterization, and chromatographic analysis of these six regioisomeric methoxy methyl phenethylamines. Additionally, the mass spectral and chromatographic properties of these compounds will be compared to the isobaric 2,3- and 3,4-methylenedioxyphenethyl-amines of the same side chain. The six regioisomeric methoxy-methyl-phenethylamines were synthesized from commercially available starting materials. Side chain differentiation by mass spectrometry was possible after the formation of the perfluoroacyl derivatives, pentafluoropropionylamides (PFPA) and heptafluorobutrylamides (HFBA). Gas chromatographic separation on Rtx-1 was successful at resolving the perfluoroacyl derivatives of the 4-methoxy-3-methyl phenethylamines from those of the 4-methoxy-2-methyl phenethylamines. The 4-methoxy-3-methyl-phenethylamine derivatives eluted before the 4-methoxy-2-methyl-phenethylamine derivatives as both the PFPA and HFBA derivatives.

GC-MS and GC-IRD studies on the ring isomers of N-methyl-2-methoxyphenyl-3-butanamines (MPBA) related to 3,4-MDMA.

PubMed

Awad, Tamer; Maher, Hadir M; DeRuiter, Jack; Clark, C Randall

2011-05-01

The mass spectra of the controlled substance 3,4-MDMA and its regioisomer 2,3-MDMA are characterized by an imine fragment base peak at m/z 58 and additional fragments at m/z 135/136 for the methylenedioxybenzyl cation and radical cation, respectively. Three positional ring methoxy isomers of N-methyl-2-(methoxyphenyl)-3-butanamine (MPBA) have an isobaric relationship to 2,3- and 3,4-MDMA. All five compounds have the same molecular weight and produce similar EI mass spectra. This lack of mass spectral specificity for the isomers in addition to the possibility of chromatographic co-elution could result in misidentification. The lack of reference materials for the potential imposter molecules constitutes a significant analytical challenge. Perfluoroacylation of the amine group reduced the nitrogen basicity and provided individual fragmentation pathways for discrimination among these compounds based on unique fragment ions and the relative abundance of common ions. Studies using gas chromatography with infrared detection provided additional structure-IR spectra relationships. The underivatized amines and the perfluoroacylated derivatives (PFPA and HFBA) were resolved by capillary gas chromatography on a 100% dimethylpolysiloxane stationary phase. The perfluoroacylated derivatives showed better resolution on a cyclodextrin modified stationary phase.

40 CFR 721.225 - 2-Chloro-N-methyl-N-substituted acetamide (generic name).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false 2-Chloro-N-methyl-N-substituted... Specific Chemical Substances § 721.225 2-Chloro-N-methyl-N-substituted acetamide (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance 2-chloro-N...

40 CFR 721.225 - 2-Chloro-N-methyl-N-substituted acetamide (generic name).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 2-Chloro-N-methyl-N-substituted... Specific Chemical Substances § 721.225 2-Chloro-N-methyl-N-substituted acetamide (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance 2-chloro-N...

Experimental and computational approaches of a novel methyl (2E)-2-{[N-(2-formylphenyl)(4-methylbenzene)sulfonamido]methyl}-3-(4-chlorophenyl)prop-2-enoate: A potential antimicrobial agent and an inhibition of penicillin-binding protein

NASA Astrophysics Data System (ADS)

Murugavel, S.; Vetri velan, V.; Kannan, Damodharan; Bakthadoss, Manickam

2016-07-01

The title compound methyl(2E)-2-{[N-(2-formylphenyl) (4-methylbenzene)sulfonamido]methyl}-3-(4-chlorophenyl) prop-2-enoate (MFMSC) has been synthesized and single crystals were grown by slow evaporation solution growth technique at room temperature. Structural and vibrational spectroscopic studies were carried out by using single crystal X-ray diffraction, FT-IR and NMR spectral analysis together with DFT method using GAUSSIAN'03 software. The detailed interpretation of the vibrational spectra has been carried out by VEDA program. NBO analysis, Mulliken charge analysis, HOMO-LUMO, MEP, Global chemical reactivity descriptors and thermodynamic properties have been analyzed. The hyperpolarisability calculation reveals the present material has a reasonably good propensity for nonlinear optical activity. The obtained antimicrobial activity results indicate that the compound shows good to moderate activity against all tested bacterial and fungal pathogens. A computational study was also carried out to predict the drug-likeness and ADMET properties of the title compound. Due to the different potential biological activity of the title compound, molecular docking study is also reported and the compound might exhibit inhibitory activity against penicillin-binding protein PBP-2X.

40 CFR 721.1085 - Benzenamine,4,4′-methylenebis[N-ethyl-N-methyl-.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Benzenamine,4,4â²-methylenebis[N-ethyl-N-methyl-. 721.1085 Section 721.1085 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.1085 Benzenamine,4,4′-methylenebis[N-ethyl-N-methyl-. (a) Chemical...

40 CFR 721.1085 - Benzenamine,4,4′-methylenebis[N-ethyl-N-methyl-.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Benzenamine,4,4â²-methylenebis[N-ethyl-N-methyl-. 721.1085 Section 721.1085 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.1085 Benzenamine,4,4′-methylenebis[N-ethyl-N-methyl-. (a) Chemical...

INTERLABORATORY STUDY OF A THERMOSPRAY-LIQUID CHROMATOGRAPHIC/MASS SPECTROMETRIC METHOD FOR SELECTED N-METHYL CARBAMATES, N-METHYL CARBAMOYLOXIMES, AND SUBSTITUTED UREA PESTICIDES

EPA Science Inventory

A thermospray-liquid chromatographic/mass spectrometric (TS-LC/MS) method was evaluated in an interlaboratory study for determining 3 N-methyl carbamates (bendiocarb, carbaryl, and carbofuran), 3-N-methyl carbamoyloximes (aldicarb, methomyl, and oxamyl), 2 substituted urea pestic...

Analysis of ecstasy tablets: comparison of reflectance and transmittance near infrared spectroscopy.

PubMed

Schneider, Ralph Carsten; Kovar, Karl-Artur

2003-07-08

Calibration models for the quantitation of commonly used ecstasy substances have been developed using near infrared spectroscopy (NIR) in diffuse reflectance and in transmission mode by applying seized ecstasy tablets for model building and validation. The samples contained amphetamine, N-methyl-3,4-methylenedioxy-amphetamine (MDMA) and N-ethyl-3,4-methylenedioxy-amphetamine (MDE) in different concentrations. All tablets were analyzed using high performance liquid chromatography (HPLC) with diode array detection as reference method. We evaluated the performance of each NIR measurement method with regard to its ability to predict the content of each tablet with a low root mean square error of prediction (RMSEP). Best calibration models could be generated by using NIR measurement in transmittance mode with wavelength selection and 1/x-transformation of the raw data. The models build in reflectance mode showed higher RMSEPs using as data pretreatment, wavelength selection, 1/x-transformation and a second order Savitzky-Golay derivative with five point smoothing was applied to obtain the best models. To estimate the influence of inhomogeneities in the illegal tablets, a calibration of the destroyed, i.e. triturated samples was build and compared to the corresponding data of the whole tablets. The calibrations using these homogenized tablets showed lower RMSEPs. We can conclude that NIR analysis of ecstasy tablets in transmission mode is more suitable than measurement in diffuse reflectance to obtain quantification models for their active ingredients with regard to low errors of prediction. Inhomogeneities in the samples are equalized when measuring the tablets as powdered samples.

N-(3-azidophenyl)-N-methyl-N'-([4-1H]- and [4-3H]-1-naphthyl)guanidine. A potent and selective ligand designed as a photoaffinity label for the phencyclidine site of the N-methyl-D-aspartate receptor.

PubMed

Gee, K R; Durant, G J; Holmes, D L; Magar, S S; Weber, E; Wong, S T; Keana, J F

1993-01-01

A novel radiolabeled photoaffinity ligand has been synthesized for the phencyclidine (PCP) site of the N-methyl-D-aspartate (NMDA) receptor. N-(3-Azidophenyl)-N-methyl-N'-([4-3H]-1-naphthyl)guanidine (13) was prepared with a specific activity of 25 Ci/mmol by diazotization of N-(3-aminophenyl)-N-methyl-N'-([4-3H]-1-naphthyl)guanidine (12) followed by treatment with sodium azide. Guanidine 12 was obtained by catalytic tritiation of N-(4-bromo-1-naphthyl)-N'-methyl-N'-(3-nitrophenyl)guanidine (11). The nontritiated analog 5 of 13 was prepared beginning with N-methyl-N'-1-naphthyl-N-(3-nitrophenyl)guanidine (9). The guanidines 9 and 11 were prepared in moderate yield by the aluminum chloride-catalyzed reaction of N-methyl-3-nitroaniline hydrochloride with 1-naphthylcyanamide and 4-bromo-1-naphthylcyanamide, respectively. Azide 5 showed high selectivity and affinity (IC50 = 100 nM vs [3H]MK801; 3000 nM vs [3H]ditolylguanidine) for the PCP site of the NMDA receptor in guinea pig brain homogenate. Photolabeling experiments with 13, however, failed to radiolabel a significant amount of receptor polypeptide.

A fatal trip with ecstasy: a case of 3,4-methylenedioxymethamphetamine/3,4- methylenedioxyamphetamine toxicity.

PubMed Central

Coore, J R

1996-01-01

Since the late 1980s there have been a number of reports about the complications associated with using the designer drug 3,4-methylenedioxymethamphetamine (MDMA) or 'ecstasy'. Although this drug has been widely abused in the past, the potentially fatal complications have arisen recently mainly due to the circumstances of its use at all-night dance sessions or 'raves'. A combination of direct toxicity and strenuous physical exertion can lead to hyperthermia and its attendant complications. The following case illustrates some of the possible consequences following ingestion of 'ecstasy', and reiterates the importance of prompt recognition and treatment in preventing the development of irreversible sequelae. PMID:8709087

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.

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...

21 CFR 500.1410 - N-methyl-2-pyrrolidone.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false N-methyl-2-pyrrolidone. 500.1410 Section 500.1410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Used in Food-Producing Animals § 500.1410 N-methyl-2-pyrrolidone. (a) Standard for residues. No...

21 CFR 500.1410 - N-methyl-2-pyrrolidone.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false N-methyl-2-pyrrolidone. 500.1410 Section 500.1410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Used in Food-Producing Animals § 500.1410 N-methyl-2-pyrrolidone. (a) Standard for residues. No...

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...

Toxicokinetics of amphetamines: metabolism and toxicokinetic data of designer drugs, amphetamine, methamphetamine, and their N-alkyl derivatives.

PubMed

Kraemer, Thomas; Maurer, Hans H

2002-04-01

This paper reviews the toxicokinetics of amphetamines. The designer drugs MDA (methylenedioxy-amphetamine, R,S-1-(3;,4;-methylenedioxyphenyl)2-propanamine), MDMA (R,S-methylenedioxymethamphetamine), and MDE (R,S-methylenedioxyethylamphetamine), as well as BDB (benzodioxolylbutanamine; R,S-1-(1;,3;-benzodioxol-5;-yl)-2-butanamine or R,S-1-(3;,4;-methylenedioxyphenyl)-2-butanamine) and MBDB (R,S-N-methyl-benzodioxolylbutanamine), were taken into consideration, as were the following N-alkylated amphetamine derivatives: amphetaminil, benzphetamine, clobenzorex, dimethylamphetamine, ethylamphetamine, famprofazone, fencamine, fenethylline, fenproporex, furfenorex, mefenorex, mesocarb, methamphetamine, prenylamine, and selegiline. English-language publications from 1995 to 2000 were reviewed. Papers describing identification of metabolites or cytochrome P450 isoenzyme-dependent metabolism and papers containing pharmacokinetic/toxicokinetic data were considered and summarized. The implications of toxicokinetics for toxicologic assessment or for interpretation in forensic cases are discussed.

Biotransformation and pharmacokinetics of the nitrate trans-2-amino-2-methyl-N-(4-nitroxycyclohexyl)-propionamide in dogs.

PubMed

Pressmar, F; Neidlein, R; Strein, K

1992-11-01

The biotransformation and the pharmacokinetic behavior of the organic nitrate trans-2-Amino-2-methyl-N-(4-nitroxycyclohexyl)-propionamide (BM 12.1179, CAS 129795-96-6) were examined in dogs. BM 12.1179 was predominantly eliminated by urinary excretion, and the unchanged molecule prevailed in urine as well as in plasma. By means of various mass spectroscopic methods, the chemical structures of the metabolites were elucidated. As metabolites trans-2-amino-2-methyl-N-(4-hydroxycyclohexyl)-propionamide and trans-2-amino-2-methyl-N-(4-oxocyclohexyl)-propionamide were formed. Urine levels of the main metabolite were determined by high-pressure liquid chromatography; plasma and urine levels of BM 12.1179 were determined by capillary gas chromatography. The absolute bioavailability of BM 12.1179 was 80-100%. The plasma protein binding was about 34% which is high in comparison to other organic nitrates. BM 12.1179 represents a long-acting organic nitrate in that it shows a slow reductive denitration, and a long elimination half-life of about 10 h.

Structural and spectroscopic characterization of methyl isocyanate, methyl cyanate, methyl fulminate, and acetonitrile N-oxide using highly correlated ab initio methods.

PubMed

Dalbouha, S; Senent, M L; Komiha, N; Domínguez-Gómez, R

2016-09-28

Various astrophysical relevant molecules obeying the empirical formula C 2 H 3 NO are characterized using explicitly correlated coupled cluster methods (CCSD(T)-F12). Rotational and rovibrational parameters are provided for four isomers: methyl isocyanate (CH 3 NCO), methyl cyanate (CH 3 OCN), methyl fulminate (CH 3 ONC), and acetonitrile N-oxide (CH 3 CNO). A CH 3 CON transition state is inspected. A variational procedure is employed to explore the far infrared region because some species present non-rigidity. Second order perturbation theory is used for the determination of anharmonic frequencies, rovibrational constants, and to predict Fermi resonances. Three species, methyl cyanate, methyl fulminate, and CH 3 CON, show a unique methyl torsion hindered by energy barriers. In methyl isocyanate, the methyl group barrier is so low that the internal top can be considered a free rotor. On the other hand, acetonitrile N-oxide presents a linear skeleton, C 3v symmetry, and free internal rotation. Its equilibrium geometry depends strongly on electron correlation. The remaining isomers present a bend skeleton. Divergences between theoretical rotational constants and previous parameters fitted from observed lines for methyl isocyanate are discussed on the basis of the relevant rovibrational interaction and the quasi-linearity of the molecular skeleton.

Structural and spectroscopic characterization of methyl isocyanate, methyl cyanate, methyl fulminate, and acetonitrile N-oxide using highly correlated ab initio methods

NASA Astrophysics Data System (ADS)

Dalbouha, S.; Senent, M. L.; Komiha, N.; Domínguez-Gómez, R.

2016-09-01

Various astrophysical relevant molecules obeying the empirical formula C2H3NO are characterized using explicitly correlated coupled cluster methods (CCSD(T)-F12). Rotational and rovibrational parameters are provided for four isomers: methyl isocyanate (CH3NCO), methyl cyanate (CH3OCN), methyl fulminate (CH3ONC), and acetonitrile N-oxide (CH3CNO). A CH3CON transition state is inspected. A variational procedure is employed to explore the far infrared region because some species present non-rigidity. Second order perturbation theory is used for the determination of anharmonic frequencies, rovibrational constants, and to predict Fermi resonances. Three species, methyl cyanate, methyl fulminate, and CH3CON, show a unique methyl torsion hindered by energy barriers. In methyl isocyanate, the methyl group barrier is so low that the internal top can be considered a free rotor. On the other hand, acetonitrile N-oxide presents a linear skeleton, C3v symmetry, and free internal rotation. Its equilibrium geometry depends strongly on electron correlation. The remaining isomers present a bend skeleton. Divergences between theoretical rotational constants and previous parameters fitted from observed lines for methyl isocyanate are discussed on the basis of the relevant rovibrational interaction and the quasi-linearity of the molecular skeleton.

Synthesis, crystal structure analysis, spectral investigations, DFT computations, Biological activities and molecular docking of methyl(2E)-2-{[N-(2-formylphenyl)(4-methylbenzene) sulfonamido]methyl}-3-(4-fluorophenyl)prop-2-enoate, a potential bioactive agent

NASA Astrophysics Data System (ADS)

Murugavel, S.; Vetri Velan, V.; Kannan, Damodharan; Bakthadoss, Manickam

2016-03-01

The title compound methyl(2E)-2-{[N-(2-formylphenyl) (4-methylbenzene)sulfonamido]methyl}-3-(4-fluorophenyl) prop-2-enoate (MFMSF) has been synthesized and single crystals were grown by slow evaporation solution growth technique at room temperature. The grown crystals were characterized by FTIR, 1H NMR, 13C NMR, and single crystal X-ray diffraction. In the crystal, molecules are linked by intermolecular C-H…O hydrogen bonds forming a two-dimensional supramolecular network along [110] direction. The molecular geometry was also optimized using density functional theory (DFT/B3LYP) method with the 6-311G (d,p) basis set in ground state and compared with the experimental data. The entire vibrational assignments of wave numbers were made on the basis of potential energy distribution (PED) by VEDA 4 programme. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. In addition, NLO, MEP, Mulliken, thermodynamic properties, HOMO and LUMO energy gap were theoretically predicted. The global chemical reactivity descriptors are calculated for MFMSF and used to predict their relative stability and reactivity. The antibacterial activity of the compound was also tested against various pathogens. The molecular docking studies concede that title compound may exhibit PBP-2X inhibitor activity.

Chiral separation of 3,4-methylenedioxymeth- amphetamine and related compounds in clandestine tablets and urine samples by capillary electrophoresis/fluorescence spectroscopy.

PubMed

Huang, Yu-San; Liu, Ju-Tsung; Lin, Li-Chang; Lin, Cheng-Huang

2003-03-01

The R-(-)- and S-(+)-isomers of 3,4-methylenedioxymethamphetamine (MDMA) and its metabolite 3,4-methylenedioxyamphetamine (MDA) were prepared, identified by gas chromatography/mass spectrometry (GC/MS) and then used as standards in a series of capillary electrophoresis (CE) experiments. Using these R-(-)- and S-(+)-isomers, the distribution of (RS)-MDA and (RS)-MDMA stereoisomers in clandestine tablets and suspect urine samples were identified. Several electrophoretic parameters, such as the concentration of beta-cyclodextrin used in the electrophoretic separation and the amount of organic solvents required for the separation, were optimized.

Reduced 3,4'-bipyrazoles from a simple pyrazole precursor: synthetic sequence, molecular structures and supramolecular assembly.

PubMed

Cuartas, Viviana; Insuasty, Braulio; Cobo, Justo; Glidewell, Christopher

2017-10-01

The reaction of 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde and N-benzylmethylamine under microwave irradiation gives 5-[benzyl(methyl)amino]-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde, C 19 H 19 N 3 O, (I). Subsequent reactions under basic conditions, between (I) and a range of acetophenones, yield the corresponding chalcones. These undergo cyclocondensation reactions with hydrazine to produce reduced bipyrazoles which can be N-formylated with formic acid or N-acetylated with acetic anhydride. The structures of (I) and of representative examples from this reaction sequence are reported, namely the chalcone (E)-3-{5-[benzyl(methyl)amino]-3-methyl-1-phenyl-1H-pyrazol-4-yl}-1-(4-bromophenyl)prop-2-en-1-one, C 27 H 24 BrN 3 O, (II), the N-formyl derivative (3RS)-5'-[benzyl(methyl)amino]-3'-methyl-1',5-diphenyl-3,4-dihydro-1'H,2H-[3,4'-bipyrazole]-2-carbaldehyde, C 28 H 27 N 5 O, (III), and the N-acetyl derivative (3RS)-2-acetyl-5'-[benzyl(methyl)amino]-5-(4-methoxyphenyl)-3'-methyl-1'-phenyl-3,4-dihydro-1'H,2H-[3,4'-bipyrazole], which crystallizes as the ethanol 0.945-solvate, C 30 H 31 N 5 O 2 ·0.945C 2 H 6 O, (IV). There is significant delocalization of charge from the benzyl(methyl)amino substituent onto the carbonyl group in (I), but not in (II). In each of (III) and (IV), the reduced pyrazole ring is modestly puckered into an envelope conformation. The molecules of (I) are linked by a combination of C-H...N and C-H...π(arene) hydrogen bonds to form a simple chain of rings; those of (III) are linked by a combination of C-H...O and C-H...N hydrogen bonds to form sheets of R 2 2 (8) and R 6 6 (42) rings, and those of (IV) are linked by a combination of O-H...N and C-H...O hydrogen bonds to form a ribbon of edge-fused R 2 4 (16) and R 4 4 (24) rings.

Aberrant methylation of miR-34b is associated with long-term shiftwork: a potential mechanism for increased breast cancer susceptibility.

PubMed

Liu, Ran; Jacobs, Daniel I; Hansen, Johnni; Fu, Alan; Stevens, Richard G; Zhu, Yong

2015-02-01

Although the evidence linking exposure to light at night (LAN) and breast cancer risk continues to accumulate, the molecular mechanisms driving this association remain to be fully elucidated. We have previously suggested that long-term exposure to LAN through shiftwork may result in dysregulated patterns of methylation genome-wide. In this study, we investigate the link between miR-34b, a miRNA suggested to be an important tumor suppressor, and shiftwork-related breast cancer. Methylation states in the miR-34b promoter region were previously compared between 10 female long-term shiftworkers and 10 folate intake- and age-matched female dayworkers participating in the Danish "Diet, Cancer and Health" prospective cohort study. In order to further explore the functional role of miR-34b in breast tumorigenesis, a genome-wide expression microarray was carried out in miR-34b-overexpressed MCF-7 breast cancer cells and the identified transcripts were further analyzed for network and functional interrelatedness using Ingenuity Pathway Analysis software. We observed a 49.1 % increase in miR-34b promoter methylation among shiftworkers at a CpG site in this region (p = 0.016). Transfection of the miR-34b mimic in an MCF-7 breast cancer cell line induced differential expression of 230 transcripts that are involved in the interferon-mediated antiviral response as well as apoptotic and antiproliferative gene networks. Together, our results suggest that long-term shiftwork may increase the risk of breast cancer via methylation-based suppression of miR-34b and a consequent reduction in immunomediated anti-tumor capacity and support our previous findings that LAN may induce epigenetic alteration of cancer-relevant microRNAs.

Decarboxylase inhibition and blood pressure reduction by alpha-methyl-3,4-dihydroxy-DL-phenylalanine.

PubMed

OATES, J A; GILLESPIE, L; UDENFRIEND, S; SJOERDSMA, A

1960-06-24

alpha-Methyl-3,4-dihydroxy-DLphenylalanine has been found to be an effective inhibitor of aromatic amino acid decarboxylation in man. This was shown by decreased formation of serotonin, tryptamine, and tyramine from the precursor amino acids. Reduction of amine biosynthesis is associated with lowering of blood pressure in hypertensive patients and a transient sedative effect.

Interrupted E2F1-miR-34c-SCF negative feedback loop by hyper-methylation promotes colorectal cancer cell proliferation

PubMed Central

Yang, Shu; Wu, Bo; Sun, Haimei; Ji, Fengqing; Sun, Tingyi; Zhao, Yan; Zhou, Deshan

2015-01-01

Tumour suppressor miR-34c deficiency resulted from hyper-methylation in its promoter is believed to be one of the main causes of colorectal cancer (CRC). Till date, miR-34c has been validated as a direct target of p53; but previous evidence suggested other transcription factor(s) must be involved in miR-34c transcription. In the present study, we in the first place identified a core promoter region (−1118 to −883 bp) of pre-miR-34c which was embedded within a hyper-methylated CpG island. Secondly, E2F1 promoted miR-34c transcription by physical interaction with the miR-34c promoter at site −897 to −889 bp. The transcriptional activating effect of E2F1 on miR-34c was in a p53 independent manner but profoundly promoted in the presence of p53 with exposure to 5-aza-2′-deoxycytidine (DAC). Thirdly, stem cell factor (SCF), a miR-34c target, was specifically reduced upon an introduction of E2F1 which lead to suppression of CRC cell proliferation. The E2F1-suppressed cell proliferation was partially abrogated by additional miR-34c inhibitor, indicating that the anti-proliferation effect of E2F1 was probably through activating miR-34c-SCF axis. Finally, SCF/KIT signalling increased E2F1 production by reducing its proteosomal degradation dependent on PI3K/Akt-GSK3β pathway. In conclusion, our results suggested the existence of E2F1-miR-34c-SCF negative feedback loop which was interrupted by the hyper-methylation of miR-34c promoter in CRC cells and increased cell proliferation. PMID:26704889

Assessment of the best N(3-) donors in preparation of [M(N)(PNP)]-based (M=(99m)Tc-; (188)Re) target-specific radiopharmaceuticals: Comparison among succinic dihydrazide (SDH), N-methyl-S-methyl dithiocarbazate (HDTCZ) and PEGylated N-methyl-S-methyl dithiocarbazate (HO2C-PEG600-DTCZ).

PubMed

Carta, Davide; Jentschel, Christian; Thieme, Stefan; Salvarese, Nicola; Morellato, Nicolò; Refosco, Fiorenzo; Ruzza, Paolo; Bergmann, Ralf; Pietzsch, Hans-Jurgen; Bolzati, Cristina

2014-08-01

Succinic dihydrazide (SDH), N-methyl-S-methyl dithiocarbazate (HDTCZ) and PEGylated N-methyl-S-methyl dithiocarbazate (HO2C-PEG600-DTCZ) are nitrido nitrogen atom donors employed for the preparation of nitride [M(N)]-complexes (M=(99m)Tc and (188)Re). This study aims to compare the capability and the efficiency of these three N(3-) group donors, in the preparation of [M(N)PNP]-based target-specific compounds (M=(99m)Tc, (188)Re; PNP=aminodiphosphine). For this purpose, three different kit formulations (SDH kit; HO2C-PEG600-DTCZ kit; HDTCZ kit) were assembled and used in the preparation of [M(N)(cys~)(PNP3)](0/+) complexes (cys~=cysteine derivate ligands). For each formulation, the radiochemical yield (RCY) of the [M(N)(~cys)(PNP3)] compounds, was determined by HPLC. The deviation of the percentage of RCY, due to changes in concentration of the N(3-) donors and of the exchanging ligand, was determined. For (99m)Tc, data clearly show that HDTCZ is the most efficient donor of N(3-); however, SDH is the most suitable nitrido nitrogen atom donor for the preparation of [(99m)Tc(N)(PNP)]-based target-specific agents with high specific activity. When HO2C-PEG600-DTCZ or HDTCZ are used in N(3-) donation, high amounts of the exchanging ligand (10(-4)M) were required for the formation of the final complex in acceptable yield. The possibility to use microgram amounts of HDTCZ also in [(188)Re(N)] preparation (0.050mg) reduces its ability to compete in ligand exchange reactions, minimizing the quantity of chelators required to obtain the final complex in high yield. This finding can be exploit for increasing the radiolabeling efficiency in [(188)Re(N)]-radiopharmaceutical preparations compared to the previously reported HDTCZ-based procedure, notwithstanding a purification process could be necessary to improve the specific activity of the complexes. Copyright © 2014 Elsevier Inc. All rights reserved.

40 CFR 721.1070 - Benzenamine, 4-methoxy-2-methyl-N-(3-methylphenyl).

Code of Federal Regulations, 2010 CFR

2010-07-01

... as benzenamine, 4-methoxy-2-methyl-N-(3-methylphenyl) (PMN P-01-152; CAS No. 93072-06-1) is subject... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Benzenamine, 4-methoxy-2-methyl-N-(3... Specific Chemical Substances § 721.1070 Benzenamine, 4-methoxy-2-methyl-N-(3-methylphenyl). (a) Chemical...

N-methylated tryptamine derivatives in citrus genus plants: identification of N,N,N-trimethyltryptamine in bergamot.

PubMed

Servillo, Luigi; Giovane, Alfonso; Balestrieri, Maria Luisa; Cautela, Domenico; Castaldo, Domenico

2012-09-19

The occurrence of N-methylated tryptamine derivatives in bergamot plant (Citrus bergamia Risso et Poit) is reported for the first time. Interestingly, the most abundant of these substances is N,N,N-trimethyltryptamine, which has not been previously identified in any citrus plant. The N-methylated tryptamine derivatives were identified and quantitated in leaves, peel, juice, and seeds by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. N,N,N-Trimethyltryptamine was confirmed by MS(3) and comparison with the synthesized authentic standard. In addition, the study of the distribution of tryptophan, tryptamine, N-methyltryptamine, N,N-dimethyltryptamine, and N,N,N-trimethyltryptamine indicated that these compounds are differently expressed in the various tissues of the bergamot plant. Intriguingly, chemically synthesized N,N,N-trimethyltryptamine was reported to possess nicotine-like activity being a stimulant of parasympathetic ganglia by exerting its action on acetylcholine receptors. On this basis, the identification of N,N,N-trimethyltryptamine at a relatively high level in leaves suggests a possible role in a physiological mechanism of plant defense.

Determination of the designer drugs 3, 4-methylenedioxymethamphetamine, 3,4-methylenedioxyethylamphetamine, and 3,4-methylenedioxyamphetamine with HPLC and fluorescence detection in whole blood, serum, vitreous humor, and urine.

PubMed

Clauwaert, K M; Van Bocxlaer, J F; De Letter, E A; Van Calenbergh, S; Lambert, W E; De Leenheer, A P

2000-12-01

The popular designer drugs 3, 4-methylenedioxymethamphetamine (MDMA) and 3, 4-methylenedioxyethylamphetamine (MDEA) can be determined in serum, whole blood, and urine, but also in vitreous humor. The latter matrix is interesting when dealing with decomposed bodies in a toxicological setting. After extraction, chromatographic separation was achieved on a narrow-bore C(18) column by gradient elution with fluorometric detection; results were confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method was linear over the range of 2-1000 microg/L for whole blood, serum, and vitreous humor, and 0.1-5 mg/L for urine. Extraction recoveries were >70%, imprecision (CV) was 2.5-19%, and analytical recoveries were 95.5-104.4%. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.8 and 2 microg/L, respectively, for whole blood, serum, and vitreous humor, and 2.5 microg/L and 0.1 mg/L, respectively, for urine. Excellent correlations between the quantitative LC-fluorescence and LC-MS/MS results were obtained. We found the following concentrations in a thanatochemical distribution study in rabbits: in serum, 5.3-685 microg/L for MDMA and from the LOQ to 14.5 microg/L for 3, 4-methylenedioxyamphetamine (MDA); in whole blood, 19.7-710 microg/L for MDMA and from the LOQ to 17.8 microg/L for MDA; in vitreous humor, 12.1-97.8 microg/L for MDMA and from the LOQ to 3.86 microg/L for MDA. In routine toxicological urine samples, concentrations ranged from LOQ to 14.62 mg/L for MDA, from LOQ to 157 mg/L for MDMA, and from LOQ to 32.54 mg/L for MDEA. The HPLC method described is sensitive, specific, and suitable for the determination of MDMA, MDEA, and MDA in whole blood, serum, vitreous humor, and urine.

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.

5-Bromo-N-methyl­pyrimidin-2-amine

PubMed Central

Yang, Qi; Xu, Ning; Zhu, Kai; Lv, Xiaoping; Han, Ping-fang

2012-01-01

In the title mol­ecule, C5H6BrN3, the pyrimidine ring is essentially planar, with an r.m.s. deviation of 0.007 Å. The Br and N atoms substituted to the pyrimidine ring are coplanar with the ring [displacements = 0.032 (1) and 0.009 (5) Å, respectively], while the methyl C atom lies 0.100 (15) Å from this plane with a dihedral angle between the pyrimidine ring and the methyl­amine group of 4.5 (3)°. In the crystal, C—H⋯N, C—H⋯Br and N—H⋯N hydrogen bonds link the mol­ecules into a two-dimensional network in the (011) plane. PMID:22259398

Methylation profiling identified novel differentially methylated markers including OPCML and FLRT2 in prostate cancer.

PubMed

Wu, Yu; Davison, Jerry; Qu, Xiaoyu; Morrissey, Colm; Storer, Barry; Brown, Lisha; Vessella, Robert; Nelson, Peter; Fang, Min

2016-04-02

To develop new methods to distinguish indolent from aggressive prostate cancers (PCa), we utilized comprehensive high-throughput array-based relative methylation (CHARM) assay to identify differentially methylated regions (DMRs) throughout the genome, including both CpG island (CGI) and non-CGI regions in PCa patients based on Gleason grade. Initially, 26 samples, including 8 each of low [Gleason score (GS) 6] and high (GS ≥7) grade PCa samples and 10 matched normal prostate tissues, were analyzed as a discovery cohort. We identified 3,567 DMRs between normal and cancer tissues, and 913 DMRs distinguishing low from high-grade cancers. Most of these DMRs were located at CGI shores. The top 5 candidate DMRs from the low vs. high Gleason comparison, including OPCML, ELAVL2, EXT1, IRX5, and FLRT2, were validated by pyrosequencing using the discovery cohort. OPCML and FLRT2 were further validated in an independent cohort consisting of 20 low-Gleason and 33 high-Gleason tissues. We then compared patients with biochemical recurrence (n=70) vs. those without (n=86) in a third cohort, and they showed no difference in methylation at these DMR loci. When GS 3+4 cases and GS 4+3 cases were compared, OPCML-DMR methylation showed a trend of lower methylation in the recurrence group (n=30) than in the no-recurrence (n=52) group. We conclude that whole-genome methylation profiling with CHARM revealed distinct patterns of differential DNA methylation between normal prostate and PCa tissues, as well as between different risk groups of PCa as defined by Gleason scores. A panel of selected DMRs may serve as novel surrogate biomarkers for Gleason score in PCa.

Crystal structure of 2-bromo-3-di­methyl­amino-N,N,N′,N′,4-penta­methyl-4-(tri­methyl­sil­yloxy)pent-2-eneamidinium bromide

PubMed Central

Tiritiris, Ioannis; Kress, Ralf; Kantlehner, Willi

2015-01-01

The reaction of the ortho­amide 1,1,1-tris­(di­methyl­amino)-4-methyl-4-(tri­methyl­sil­yloxy)pent-2-yne with bromine in benzene, yields the title salt, C15H33BrN3OSi+·Br−. The C—N bond lengths in the amidinium unit are 1.319 (6) and 1.333 (6) Å, indicating double-bond character, pointing towards charge delocalization within the NCN plane. The C—Br bond length of 1.926 (5) Å is characteristic for a C—Br single bond. Additionally, there is a bromine–bromine inter­action [3.229 (3) Å] present involving the anion and cation. In the crystal, weak C—H⋯Br inter­actions between the methyl H atoms of the cation and the bromide ions are present. PMID:26870498

Reevaluation of the effect of ellagic acid on N-methyl-N-nitrosourea DNA alkylation and mutagenicity

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

Lord, H.L.; Josephy, P.D.; Snieckus, V.A.

N-Methyl-N-nitrosourea (MNU) is a reactive, mutagenic methylating agent. MNU methylates DNA at various sites, including guanine N{sup 7}, guanine O{sup 6}, and adenine N{sup 3}. Dixit and Gold ((1986) Proc. Natl, Acad. Sci. U.S.A. 83, 8039-8043) reported that ellagic acid, a phenolic natural product, inhibited the mutagenicity of MNU in Salmonella typhimurium strain TA 100, inhibited salmon sperm DNA alkylation by ({sup 3}H)MNU, and also greatly reduced the ratio of guanine O{sup 6} to guanine N{sup 7} alkylation. We have examined the MNU-induced alkylation of calf thymus DNA and evaluated the effect of ellagic acid on this binding. Ellagic acidmore » had only a slight effect on total alkylation and did not alter the ratio of methylation at guanine-O{sup 6} and -N{sup 7} positions. In further experiments, ellagic acid did not significantly inhibit MNU mutagenicity. These findings do not support the potential use of ellagic acid as an inhibitor of biological damage induced by nitrosoureas.« less

Late Maternal Folate Supplementation Rescues from Methyl Donor Deficiency-Associated Brain Defects by Restoring Let-7 and miR-34 Pathways.

PubMed

Geoffroy, Andréa; Kerek, Racha; Pourié, Grégory; Helle, Déborah; Guéant, Jean-Louis; Daval, Jean-Luc; Bossenmeyer-Pourié, Carine

2017-09-01

The micronutrients folate and vitamin B12 are essential for the proper development of the central nervous system, and their deficiency during pregnancy has been associated with a wide range of disorders. They act as methyl donors in the one-carbon metabolism which critically influences epigenetic mechanisms. In order to depict further underlying mechanisms, we investigated the role of let-7 and miR-34, two microRNAs regulated by methylation, on a rat model of maternal deficiency. In several countries, public health policies recommend periconceptional supplementation with folic acid. However, the question about the duration and periodicity of supplementation remains. We therefore tested maternal supply (3 mg/kg/day) during the last third of gestation from embryonic days (E) 13 to 20. Methyl donor deficiency-related developmental disorders at E20, including cerebellar and interhemispheric suture defects and atrophy of selective cerebral layers, were associated with increased brain expression (by 2.5-fold) of let-7a and miR-34a, with subsequent downregulation of their regulatory targets such as Trim71 and Notch signaling partners, respectively. These processes could be reversed by siRNA strategy in differentiating neuroprogenitors lacking folate, with improvement of their morphological characteristics. While folic acid supplementation helped restoring the levels of let-7a and miR-34a and their downstream targets, it led to a reduction of structural and functional defects taking place during the perinatal period. Our data outline the potential role of let-7 and miR-34 and their related signaling pathways in the developmental defects following gestational methyl donor deficiency and support the likely usefulness of late folate supplementation in at risk women.

40 CFR 721.2275 - N,N,N′,N′-Tetrakis(oxi-ranyl- methyl)-1,3-cyclohexane di-meth-anamine.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false N,N,Nâ²,Nâ²-Tetrakis(oxi-ranyl- methyl... Significant New Uses for Specific Chemical Substances § 721.2275 N,N,N′,N′-Tetrakis(oxi-ranyl- methyl)-1,3... chemical substance identified as N,N,N′,N′-tetrakis(oxiranylmethyl)-1,3-cyclohexanedimethanamine (P-84-7...

40 CFR 721.2275 - N,N,N′,N′-Tetrakis(oxi-ranyl- methyl)-1,3-cyclohexane di-meth-anamine.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false N,N,Nâ²,Nâ²-Tetrakis(oxi-ranyl- methyl... Significant New Uses for Specific Chemical Substances § 721.2275 N,N,N′,N′-Tetrakis(oxi-ranyl- methyl)-1,3... chemical substance identified as N,N,N′,N′-tetrakis(oxiranylmethyl)-1,3-cyclohexanedimethanamine (P-84-7...

40 CFR 721.5540 - 1H,3H,5H-oxazolo [3,4-c] oxazole, dihydro-7a-methyl-.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1H,3H,5H-oxazolo [3,4-c] oxazole... Specific Chemical Substances § 721.5540 1H,3H,5H-oxazolo [3,4-c] oxazole, dihydro-7a-methyl-. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as 1H,3H,5H...

Methyl N-phenyl carbamate synthesis from aniline and methyl formate: carbon recycling to chemical products.

PubMed

Yalfani, Mohammad S; Lolli, Giulio; Müller, Thomas E; Wolf, Aurel; Mleczko, Leslaw

2015-02-01

Methyl N-phenyl carbamate was synthesized from aniline by using methyl formate as a green and efficient carbonylating agent. High yields were obtained at milder reaction conditions compared to the conventional CO/CH3 OH route. Studies on the reaction sequence led to suggest an alternative and more efficient route to the carbamate via formanilide as intermediate. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

4-Methyl-N-(1-methyl-1H-indazol-5-yl)benzene-sulfonamide.

PubMed

Chicha, Hakima; Oulemda, Bassou; Rakib, El Mostapha; Saadi, Mohamed; El Ammari, Lahcen

2013-01-01

In the title compound, C15H15N3O2S, the fused ring system is close to planar, the largest deviation from the mean plane being 0.030 (2) Å, and makes a dihedral angle of 48.84 (9)° with the benzene ring belonging to the methyl-benzene-sulfonamide moiety. In the crystal, mol-ecules are -connected through N-H⋯N hydrogen bonds and weak C-H⋯O contacts, forming a two-dimensional network parallel to (001).

Preventive effects of fructose and N-acetyl-L-cysteine against cytotoxicity induced by the psychoactive compounds N-methyl-5-(2-aminopropyl)benzofuran and 3,4-methylenedioxy-N-methamphetamine in isolated rat hepatocytes.

PubMed

Nakagawa, Yoshio; Suzuki, Toshinari; Inomata, Akiko

2018-02-01

Psychoactive compounds, N-methyl-5-(2-aminopropyl)benzofuran (5-MAPB) and 3,4-methylenedioxy-N-methamphetamine (MDMA), are known to be hepatotoxic in humans and/or experimental animals. As previous studies suggested that these compounds elicited cytotoxicity via mitochondrial dysfunction and/or oxidative stress in rat hepatocytes, the protective effects of fructose and N-acetyl-l-cysteine (NAC) on 5-MAPB- and MDMA-induced toxicity were studied in rat hepatocytes. These drugs caused not only concentration-dependent (0-4 mm) and time-dependent (0-3 hours) cell death accompanied by the depletion of cellular levels of adenosine triphosphate (ATP) and glutathione (reduced form; GSH) but also an increase in the oxidized form of GSH. The toxic effects of 5-MAPB were greater than those of MDMA. Pretreatment of hepatocytes with either fructose at a concentration of 10 mm or NAC at a concentration of 2.5 mm prevented 5-MAPB-/MDMA-induced cytotoxicity. In addition, the exposure of hepatocytes to 5-MAPB/MDMA caused the loss of mitochondrial membrane potential, although the preventive effect of fructose was weaker than that of NAC. These results suggest that: (1) 5-MAPB-/MDMA-induced cytotoxicity is linked to mitochondrial failure and depletion of cellular GSH; (2) insufficient cellular ATP levels derived from mitochondrial dysfunction were ameliorated, at least in part, by the addition of fructose; and (3) GSH loss via oxidative stress was prevented by NAC. Taken collectively, these results indicate that the onset of toxic effects caused by 5-MAPB/MDMA may be partially attributable to cellular energy stress as well as oxidative stress. Copyright © 2017 John Wiley & Sons, Ltd.

Two-step iron(0)-mediated N-demethylation of N-methyl alkaloids.

PubMed

Kok, Gaik B; Pye, Cory C; Singer, Robert D; Scammells, Peter J

2010-07-16

A mild and simple two-step Fe(0)-mediated N-demethylation of a number of tertiary N-methyl alkaloids is described. The tertiary N-methylamine is first oxidized to the corresponding N-oxide, which is isolated as the hydrochloride salt. Subsequent treatment of the N-oxide hydrochloride with iron powder readily provides the N-demethylated amine. Representative substrates include a number of opiate and tropane alkaloids. Key intermediates in the synthesis of semisynthetic 14-hydroxy pharmaceutical opiates such as oxycodone and oxymorphone are also readily N-demethylated using this method.

MDMA (N-methyl-3,4-methylenedioxyamphetamine) and its stereoisomers: Similarities and differences in behavioral effects in an automated activity apparatus in mice.

PubMed

Young, Richard; Glennon, Richard A

2008-01-01

Racemic MDMA (0.3-30 mg/kg), S(+)-MDMA (0.3-30 mg/kg), R(-)-MDMA (0.3-50 mg/kg) and saline vehicle (10 ml/kg) were comprehensively evaluated in fully automated and computer-integrated activity chambers, which were designed for mice, and provided a detailed analysis of the frequency, location, and/or duration of 18 different activities. The results indicated that MDMA and its isomers produced stimulation of motor actions, with S(+)-MDMA and (+/-)-MDMA usually being more potent than R(-)-MDMA in measures such as movement (time, distance, velocity), margin distance, rotation (clockwise and counterclockwise), and retraced activities. Interestingly, racemic MDMA appeared to exert a greater than expected potency and/or an enhanced effect on measures such as movement episodes, center actions (entries and distance), clockwise rotations, and jumps; actions that might be explained by additive or synergistic (i.e. potentiation) effects of the stereoisomers. In other measures, the enantiomers displayed different effects: S(+)-MDMA produced a preference to induce counterclockwise (versus clockwise) rotations, and each isomer exerted a different profile of effect on vertical activities and jumps. Furthermore, each isomer of MDMA appeared to attenuate the effect of its opposite enantiomer on some behaviors; antagonism effects that were surmised from a lack of expected activities by racemic MDMA. S(+)-MDMA (but not R(-)-MDMA), for example, produced an increase in vertical entries (rearing) and a preference to increase counterclockwise (versus clockwise) rotations; (+/-)-MDMA also should have induced such effects but did not. Apparently, R(-)-MDMA, when combined with S(+)-MDMA to form (+/-)-MDMA, prevented the appearance of those increases (from control) in activities. Similarly, R(-)-MDMA (but not S(+)-MDMA) produced increases in episodes (i.e. jumps) and vertical distance that racemic MDMA also should have, but were not, exhibited. Evidently, the presence of S(+)-MDMA in the racemic mixture inhibited the appearance of those increases (from control) in behavior. Taken together, the various and complex effects of MDMA and its stereoisomers are noted and a strategy is suggested for future studies that stresses the importance of steric effects and interplay, probable interaction(s) with various neurotransmitters, and interaction(s) with the particular behavioral or biological event (or action) being measured.

MDMA (N-methyl-3,4-methylenedioxyamphetamine) and its Stereoisomers: Similarities and Differences in Behavioral Effects in an Automated Activity Apparatus in Mice

PubMed Central

Young, Richard; Glennon, Richard A.

2010-01-01

Racemic MDMA (0.3 – 30 mg/kg), S(+)-MDMA (0.3 – 30 mg/kg), R(-)-MDMA (0.3 – 50 mg/kg) and saline vehicle (10 ml/kg) were comprehensively evaluated in fully automated and computer-integrated activity chambers, which were designed for mice, and provided a detailed analysis of the frequency, location, and/or duration of 18 different activities. The results indicated that MDMA and its isomers produced stimulation of motor actions, with S(+)-MDMA and (±)-MDMA usually being more potent than R(-)-MDMA in measures such as movement (time, distance, velocity), margin distance, rotation (clockwise and counterclockwise), and retraced activities. Interestingly, racemic MDMA appeared to exert a greater than expected potency and/or an enhanced effect on measures such as movement episodes, center actions (entries and distance), clockwise rotations, and jumps; actions that might be explained by additive or synergistic (i.e. potentiation) effects of the stereoisomers. In other measures, the enantiomers displayed different effects: S(+)-MDMA produced a preference to induce counterclockwise (versus clockwise) rotations, and each isomer exerted a different profile of effect on vertical activities and jumps. Furthermore, each isomer of MDMA appeared to attenuate the effect of its opposite enantiomer on some behaviors; antagonism effects that were surmised from a lack of expected activities by racemic MDMA. S(+)-MDMA (but not R(-)-MDMA), for example, produced an increase in vertical entries (rearing) and a preference to increase counterclockwise (versus clockwise) rotations; (±)-MDMA also should have induced such effects but did not. Apparently, R(-)-MDMA, when combined with S(+)-MDMA to form (±)-MDMA, prevented the appearance of those increases (from control) in activities. Similarly, R(-)-MDMA (but not S(+)-MDMA) produced increases in episodes (i.e. jumps) and vertical distance that racemic MDMA also should have, but were not, exhibited. Evidently, the presence of S(+)-MDMA in the racemic mixture inhibited the appearance of those increases (from control) in behavior. Taken together, the various and complex effects of MDMA and its stereoisomers are noted and a strategy is suggested for future studies that stresses the importance of steric effects and interplay, probable interaction(s) with various neurotransmitters, and interaction(s) with the particular behavioral or biological event (or action) being measured. PMID:17904622

Physicochemical and electrochemical properties of N-methyl-N-methoxymethylpyrrolidinium bis(fluorosulfonyl)amide and its lithium salt composites

NASA Astrophysics Data System (ADS)

Horiuchi, Shunsuke; Yoshizawa-Fujita, Masahiro; Takeoka, Yuko; Rikukawa, Masahiro

2016-09-01

The ionic liquid (IL) N-Methyl-N-methoxymethylpyrrolidinium bis(fluorosulfonyl)amide ([Pyr1,1O1][FSA]) was synthesized, and its physicochemical and electrochemical properties were investigated with respect to its application as an electrolyte in lithium-ion secondary batteries operating over a wide temperature range. [Pyr1,1O1][FSA]/Li salt (0.34 mol kg-1) composites were prepared by adding lithium bis(trifluoromethylsulfonyl)amide (LiTFSA) into the IL. [Pyr1,1O1][FSA] and [Pyr1,1O1][FSA]/LiTFSA exhibited melting temperatures (Tm) below -30 °C. [Pyr1,1O1][FSA] exhibited a higher ionic conductivity value as compared with that of the corresponding IL with only alkyl substituents. The electrochemical window for both [Pyr1,1O1][FSA] and [Pyr1,1O1][FSA]/LiTFSA was 5.1 V. Stable lithium deposition and dissolution occurred on a Ni electrode at 25 °C.

Pharmacological characterization of ecstasy synthesis byproducts with recombinant human monoamine transporters.

PubMed

Pifl, Christian; Nagy, Gabor; Berényi, Sándor; Kattinger, Alexandra; Reither, Harald; Antus, Sándor

2005-07-01

Ecstasy samples often contain byproducts of the illegal, uncontrolled synthesis of N-methyl-3,4-methylenedioxy-amphetamine or 3,4-methylenedioxymethamphetamine (MDMA). MDMA and eight chemically defined byproducts of MDMA synthesis were investigated for their interaction with the primary sites of action of MDMA, namely the human plasmalemmal monamine transporters for norepinephrine, serotonin, and dopamine [(norepinephrine transporter (NET), serotonin transporter (SERT), and dopamine transporter (DAT)]. SK-N-MC neuroblastoma and human embryonic kidney cells stably transfected with the transporter cDNA were used for uptake and release experiments. Two of the eight compounds, 1,3-bis (3,4-methylenedioxyphenyl)-2-propanamine (12) and N-formyl-1,3-bis (3,4-methylenedioxyphenyl)-prop-2-yl-amine (13) had uptake inhibitory potencies with IC50 values in the low micromolar range similar to MDMA. Compounds with nitro instead of amino groups and a phenylethenyl instead of a phenylethyl structure or a formamide or acetamide modification had IC50 values beyond 100 microM. MDMA, 12, and 13 were examined for induction of carrier-mediated release by superfusion of transporter expressing cells preloaded with the metabolically inert transporter substrate [3H]1-methyl-4-phenylpyridinium. MDMA induced release mediated by NET, SERT, or DAT with EC50 values of 0.64, 1.12, and 3.24 microM, respectively. 12 weakly released from NET- and SERT-expressing cells with maximum effects less than one-tenth of that of MDMA and did not release from DAT cells. 13 had no releasing activity. 12 and 13 inhibited release induced by MDMA, and the concentration dependence of this effect correlated with their uptake inhibitory potency at the various transporters. These results do not support a neurotoxic potential of the examined ecstasy synthesis byproducts and provide interesting structure-activity relationships on the transporters.

Direct determination of N-methyl-2-pyrrolidone metabolites in urine by HPLC-electrospray ionization-MS/MS using deuterium-labeled compounds as internal standard.

PubMed

Suzuki, Yoshihiro; Endo, Yoko; Ogawa, Masanori; Yamamoto, Shinobu; Takeuchi, Akito; Nakagawa, Tomoo; Onda, Nobuhiko

2009-11-01

N-methyl-2-pyrrolidone (NMP) has been used in many industries and biological monitoring of NMP exposure is preferred to atmospheric monitoring in occupational health. We developed an analytical method that did not include solid phase extraction (SPE) but utilized deuterium-labeled compounds as internal standard for high-performance liquid chromatography-electrospray ionization-mass spectrometry using a C30 column. Urinary concentrations of NMP and its known metabolites 5-hydoxy-N-methyl-2-pyrrolidone (5-HNMP), N-methyl-succinimide (MSI), and 2-hydroxy-N-methylsuccinimide (2-HMSI) were determined in a single run. The method provided baseline separation of these compounds. Their limits of detection in 10-fold diluted urine were 0.0001, 0.006, 0.008, and 0.03 mg/L, respectively. Linear calibration covered a biological exposure index (BEI) for urinary concentration. The within-run and total precisions (CV, %) were 5.6% and 9.2% for NMP, 3.4% and 4.2% for 5-HNMP, 3.7% and 6.0% for MSI, and 6.5% and 6.9% for 2-HMSI. The method was evaluated using international external quality assessment samples, and urine samples from workers exposed to NMP in an occupational area.

N-substituted methyl maleamates as larvicidal compounds against Aedes aegypti (Diptera: Culicidae).

PubMed

Harburguer, Laura; Gonzalez, Paula V; Gonzalez Audino, Paola; Zerba, Eduardo; Masuh, Héctor

2018-02-01

Severe human arboviral diseases can be transmitted by the mosquito Aedes aegypti (L.), including dengue, chikungunya, zika, and yellow fever. The use of larvicides in containers that can result as potential breeding places and cannot be eliminated is the main alternative in control programs. However, their continuous and widespread use caused an increase in insecticide-resistant populations of this mosquito. The aim of this study was to evaluate the effect of three N-substituted methyl maleamates as larvicides on Ae. aegypti, the N-propyl methyl maleamate (PMM), N-butyl methyl maleamate (BMM), and N-hexyl methyl maleamate (HMM). These compounds could have a different mode of action from those larvicides known so far. We evaluated the larva mortality after 1 and 24 h of exposure and we found that mortality was fast and occurs within the first 60 min. HMM was slightly more effective with LC 50 values of 0.7 and 0.3 ppm for 1 and 24 h of exposure and LC 95 of 11 and 3 ppm. Our results demonstrate that N-substituted methyl maleamates have insecticidal properties for the control of Ae. aegypti larvae. These compounds could become useful alternatives to traditional larvicides after studying their insecticidal mechanism as well as their toxicity towards non target organisms.

The Enzymatic Release of O6-methylguanine and 3-methyladenine from DNA Reacted with the Carcinogen N-methyl-N-nitrosourea

PubMed Central

Kirtikar, D. M.; Goldthwait, D. A.

1974-01-01

Endonuclease II (deoxyribonucleate oligonucleotidohydrolase, EC 3.1.4.30) of Escherichia coli has been shown to break phosphodiester bonds in alkylated DNA and depurinated DNA. The hypothesis that depurination is a step in the mechanism of the reaction with alkylated DNA is supported by in vitro experiments with DNA reacted with N-methyl-N-nitrosourea. Endonuclease II releases O6-methylguanine and 3-methyladenine, but not 7-methylguanine, from DNA that has been methylated by the carcinogen N-methyl-N-nitrosourea. PMID:4600266

Control of box C/D snoRNP assembly by N6-methylation of adenine.

PubMed

Huang, Lin; Ashraf, Saira; Wang, Jia; Lilley, David Mj

2017-09-01

N 6 -methyladenine is the most widespread mRNA modification. A subset of human box C/D snoRNA species have target GAC sequences that lead to formation of N 6 -methyladenine at a key trans Hoogsteen-sugar A·G base pair, of which half are methylated in vivo The GAC target is conserved only in those that are methylated. Methylation prevents binding of the 15.5-kDa protein and the induced folding of the RNA Thus, the assembly of the box C/D snoRNP could in principle be regulated by RNA methylation at its critical first stage. Crystallography reveals that N 6 -methylation of adenine prevents the formation of trans Hoogsteen-sugar A·G base pairs, explaining why the box C/D RNA cannot adopt its kinked conformation. More generally, our data indicate that sheared A·G base pairs (but not Watson-Crick base pairs) are more susceptible to disruption by N 6 mA methylation and are therefore possible regulatory sites. The human signal recognition particle RNA and many related Alu retrotransposon RNA species are also methylated at N6 of an adenine that forms a sheared base pair with guanine and mediates a key tertiary interaction. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

Measurement of 3,4-MDMA and related amines in diagnostic and forensic laboratories.

PubMed

Skrinska, Victor A; Gock, Susan B

2005-01-01

The phenylalkylamine derivatives, 3,4-methylenedioxymethamphetamine (MDMA, ecstasy, XTC, Adam), 3,4-methylenedioxyethamphetamine (MDEA, MDE, Eve), and 3,4-methylenedioxyamphetamine (MDA), are psychostimulants with hallucinogenic properties. MDA is also a metabolite of both MDMA and MDEA. These drugs are ring-substituted amphetamine derivatives that produce hallucinogenic, entactogenic ('love drug'), and stimulating effects. MDMA was initially developed as an appetite suppressant, however, its use as a therapeutic drug has been very limited. Because of its effects as a hallucinogenic psychostimulant with relatively low toxicity, it has emerged over the last two decades as a common recreational psychostimulant or 'club drug' at 'raves'. MDMA, MDEA, and MDA are often referred to as 'rave' or 'designer' drugs. They are produced in clandestine laboratories and have an increasing presence on the illicit drug market worldwide. Significant adverse health effects have been reported that include: serotonin neurotoxicity, severe psychiatric disorders, renal failure, malignant hyperthermia, hepatitis, rhabdomyolysis, and disseminated intravascular coagulation. A number of fatal outcomes associated with severe MDMA intoxication have been reported.

Kinetic and analytic investigations on the formation of N-nitroso-N-methyl-N-cyclohexylamine from bromhexine and nitrite.

PubMed

Schmid, J; Daneck, K; Koss, F W; Eisenbrand, G; Schlemmer, K H

1988-09-01

Bromhexine (N-methyl-N-cyclohexyl-(2-amino-3,5-dibromobenzyl)-ammoniumhydr ochloride) forms N-nitroso-N-methyl-N-cyclohexylamine (NMCA) under the conditions of the WHO Nitrosation Assay Procedure (NAP-test). The formation kinetics of this compound was investigated. The formation of NMCA depends on the square of the nitrite concentration. The reaction has a narrow pH-optimum at pH 3. The reaction is quick: After 1 h about 70% of the maximum amount of NMCA is formed. To study this reaction kinetics sensitive assays with a detection limit up to 0.5 ng/ml NMCA were developed. The stability of the components of the system, especially that of NMCA and nitrite, were further studied. The latter is rather instable under conditions found in an acidic stomach.

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

Cocaine-like discriminative stimulus effects of alpha-pyrrolidinovalerophenone, methcathinone and their 3,4-methylenedioxy or 4-methyl analogs in rhesus monkeys.

PubMed

Smith, Douglas A; Negus, S Stevens; Poklis, Justin L; Blough, Bruce E; Banks, Matthew L

2017-09-01

Synthetic cathinones are beta-ketone amphetamine analogs that have emerged as a heterogeneous class of abused compounds that function as either monoamine transporter substrates or inhibitors. Pre-clinical drug discrimination procedures are useful for interrogating structure-activity relationships of abuse-related drug effects; however, in vivo structure-activity relationship comparisons between synthetic cathinones with different mechanisms of action are lacking. The aim of the present study was to determine whether the cocaine-like discriminative stimulus effects of the monoamine transporter inhibitor alpha-pyrrolidinovalerophenone (alpha-PVP) and the monoamine transporter substrate methcathinone were differentially sensitive to 3,4-methylenedioxy and 4-methyl substitutions. Male rhesus monkeys (n = 4) were trained to discriminate intramuscular cocaine (0.32 mg/kg) from saline in a two-key food-reinforced discrimination procedure. Potency and timecourse of cocaine-like discriminative stimulus effects were determined for (±)-alpha-PVP, (±)-methcathinone and their 3,4-methylenedioxy or 4-methyl analogs. Alpha-PVP and methcathinone produced dose- and time-dependent cocaine-like effects. A 3,4-methylenedioxy addition to either alpha-PVP or methcathinone (methylone) did not alter the potency or efficacy to produce cocaine-like effects, but did prolong the time course. A 4-methyl addition to alpha-PVP (pyrovalerone) did not alter the potency or efficacy to produce cocaine-like effects, but did prolong the time course. In contrast, addition of a 4-methyl moiety to methcathinone (4MMC; mephedrone) significantly attenuated efficacy to produce cocaine-like effects. Overall, these results suggest different structural requirements for cocaine-like discriminative stimulus effects of monoamine transporter inhibitor and substrate synthetic cathinone analogs. Given that 4MMC is more hydrophobic than MDMC, these results suggest that hydrophobicity may be an important

Synthesis and properties of 4-alkoxy-2-[2-hydroxy-3-(4-o,m,p-halogenoaryl-1 -piperazinyl)propyl]-6-methyl-1H-pyrrolo-[3,4-c]pyridine-1,3(2H)-diones with analgesic and sedative activities.

PubMed

Sladowska, Helena; Sabiniarz, Aleksandra; Szkatuła, Dominika; Filipek, Barbara; Sapa, Jacek

2006-01-01

Synthesis of N-substituted derivatives of 4-alkoxy-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones (17-26) is described. The chlorides, containing OH group, used in the above synthesis can exist in two isomeric forms: chain (12, 14-16) and cyclic (12a, 14a-16a). All final imides studied exhibited analgesic activity in the "writhing syndrome" test which was superior than that of acetylsalicylic acid. In the "hot plate" test only two compounds (19, 20) were active as antinociceptive agents. Furthermore, all compounds tested significantly suppressed the spontaneous locomotor activity of mice.

Establishing the synthetic origin of amphetamines by 2H NMR spectroscopy.

PubMed

Armellin, Silvia; Brenna, Elisabetta; Fronza, Giovanni; Fuganti, Claudio; Pinciroli, Matteo; Serra, Stefano

2004-02-01

Nine samples of N-acetyl-3,4-methylenedioxyamphetamine (N-acetyl-MDA), prepared according to the most common synthetic procedures, are submitted to (2)H NMR spectroscopy. The relative deuterium content at the various sites of the molecule is shown to depend on its synthetic history. The technique provides a chemical fingerprint of N-acetyl-MDAs and it can be used to trace back the precursor materials and the synthetic pathways employed in the preparation of the samples.

Neuroprotection against traumatic brain injury by xenon, but not argon, is mediated by inhibition at the N-methyl-D-aspartate receptor glycine site.

PubMed

Harris, Katie; Armstrong, Scott P; Campos-Pires, Rita; Kiru, Louise; Franks, Nicholas P; Dickinson, Robert

2013-11-01

Xenon, the inert anesthetic gas, is neuroprotective in models of brain injury. The authors investigate the neuroprotective mechanisms of the inert gases such as xenon, argon, krypton, neon, and helium in an in vitro model of traumatic brain injury. The authors use an in vitro model using mouse organotypic hippocampal brain slices, subjected to a focal mechanical trauma, with injury quantified by propidium iodide fluorescence. Patch clamp electrophysiology is used to investigate the effect of the inert gases on N-methyl-D-aspartate receptors and TREK-1 channels, two molecular targets likely to play a role in neuroprotection. Xenon (50%) and, to a lesser extent, argon (50%) are neuroprotective against traumatic injury when applied after injury (xenon 43±1% protection at 72 h after injury [N=104]; argon 30±6% protection [N=44]; mean±SEM). Helium, neon, and krypton are devoid of neuroprotective effect. Xenon (50%) prevents development of secondary injury up to 48 h after trauma. Argon (50%) attenuates secondary injury, but is less effective than xenon (xenon 50±5% reduction in secondary injury at 72 h after injury [N=104]; argon 34±8% reduction [N=44]; mean±SEM). Glycine reverses the neuroprotective effect of xenon, but not argon, consistent with competitive inhibition at the N-methyl-D-aspartate receptor glycine site mediating xenon neuroprotection against traumatic brain injury. Xenon inhibits N-methyl-D-aspartate receptors and activates TREK-1 channels, whereas argon, krypton, neon, and helium have no effect on these ion channels. Xenon neuroprotection against traumatic brain injury can be reversed by increasing the glycine concentration, consistent with inhibition at the N-methyl-D-aspartate receptor glycine site playing a significant role in xenon neuroprotection. Argon and xenon do not act via the same mechanism.

Effects of 3,4-methylenedioxymethamphetamine (MDMA) and its main metabolites on cardiovascular function in conscious rats.

PubMed

Schindler, Charles W; Thorndike, Eric B; Blough, Bruce E; Tella, Srihari R; Goldberg, Steven R; Baumann, Michael H

2014-01-01

The cardiovascular effects produced by 3,4-methylenedioxymethamphetamine (MDMA; 'Ecstasy') contribute to its acute toxicity, but the potential role of its metabolites in these cardiovascular effects is not known. Here we examined the effects of MDMA metabolites on cardiovascular function in rats. Radiotelemetry was employed to evaluate the effects of s.c. administration of racemic MDMA and its phase I metabolites on BP, heart rate (HR) and locomotor activity in conscious male rats. MDMA (1-20 mg·kg(-1)) produced dose-related increases in BP, HR and activity. The peak effects on HR occurred at a lower dose than peak effects on BP or activity. The N-demethylated metabolite, 3,4-methylenedioxyamphetamine (MDA), produced effects that mimicked those of MDMA. The metabolite 3,4-dihydroxymethamphetamine (HHMA; 1-10 mg·kg(-1)) increased HR more potently and to a greater extent than MDMA, whereas 3,4-dihydroxyamphetamine (HHA) increased HR, but to a lesser extent than HHMA. Neither dihydroxy metabolite altered motor activity. The metabolites 4-hydroxy-3-methoxymethamphetamine (HMMA) and 4-hydroxy-3-methoxyamphetamine (HMA) did not affect any of the parameters measured. The tachycardia produced by MDMA and HHMA was blocked by the β-adrenoceptor antagonist propranolol. Our results demonstrate that HHMA may contribute significantly to the cardiovascular effects of MDMA in vivo. As such, determining the molecular mechanism of action of HHMA and the other hydroxyl metabolites of MDMA warrants further study. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Effects of 3,4-methylenedioxymethamphetamine (MDMA) and its main metabolites on cardiovascular function in conscious rats

PubMed Central

Schindler, Charles W; Thorndike, Eric B; Blough, Bruce E; Tella, Srihari R; Goldberg, Steven R; Baumann, Michael H

2014-01-01

BACKGROUND AND PURPOSE The cardiovascular effects produced by 3,4-methylenedioxymethamphetamine (MDMA; ‘Ecstasy’) contribute to its acute toxicity, but the potential role of its metabolites in these cardiovascular effects is not known. Here we examined the effects of MDMA metabolites on cardiovascular function in rats. EXPERIMENTAL APPROACH Radiotelemetry was employed to evaluate the effects of s.c. administration of racemic MDMA and its phase I metabolites on BP, heart rate (HR) and locomotor activity in conscious male rats. KEY RESULTS MDMA (1–20 mg·kg−1) produced dose-related increases in BP, HR and activity. The peak effects on HR occurred at a lower dose than peak effects on BP or activity. The N-demethylated metabolite, 3,4-methylenedioxyamphetamine (MDA), produced effects that mimicked those of MDMA. The metabolite 3,4-dihydroxymethamphetamine (HHMA; 1–10 mg·kg−1) increased HR more potently and to a greater extent than MDMA, whereas 3,4-dihydroxyamphetamine (HHA) increased HR, but to a lesser extent than HHMA. Neither dihydroxy metabolite altered motor activity. The metabolites 4-hydroxy-3-methoxymethamphetamine (HMMA) and 4-hydroxy-3-methoxyamphetamine (HMA) did not affect any of the parameters measured. The tachycardia produced by MDMA and HHMA was blocked by the β-adrenoceptor antagonist propranolol. CONCLUSIONS AND IMPLICATIONS Our results demonstrate that HHMA may contribute significantly to the cardiovascular effects of MDMA in vivo. As such, determining the molecular mechanism of action of HHMA and the other hydroxyl metabolites of MDMA warrants further study. PMID:24328722

4-Methyl-N-(1-methyl-1H-indazol-5-yl)benzene­sulfonamide

PubMed Central

Chicha, Hakima; Oulemda, Bassou; Rakib, El Mostapha; Saadi, Mohamed; El Ammari, Lahcen

2013-01-01

In the title compound, C15H15N3O2S, the fused ring system is close to planar, the largest deviation from the mean plane being 0.030 (2) Å, and makes a dihedral angle of 48.84 (9)° with the benzene ring belonging to the methyl­benzene­sulfonamide moiety. In the crystal, mol­ecules are ­connected through N—H⋯N hydrogen bonds and weak C—H⋯O contacts, forming a two-dimensional network parallel to (001). PMID:24427093

N-Methyl Inversion in Pseudo-Pelletierine

NASA Astrophysics Data System (ADS)

Vallejo-López, Montserrat; Ecija, Patricia; Cocinero, Emilio J.; Lesarri, Alberto; Basterretxea, Francisco J.; Fernández, José A.

2016-06-01

We have previously conducted rotational studies of several tropanes, since this bicyclic structural motif forms the core of different alkaloids of pharmaceutical interest. Now we report on the conformational properties and molecular structure of pseudo-pelletierine (9-methyl-9-azabicyclo[3.3.1]nonan-3-one), probed in a jet expansion with Fourier-transform microwave spectroscopy. Pseudo-pelletierine is an azabicycle with two fused six-membered rings, where the N-methyl group can produce inverting axial o equatorial conformations. The two conformations were detected in the rotational spectrum, recorded in the region 6-18 GHz. Unlike tropinone and N-methylpiperidone, where the most stable conformer is equatorial, the axial species was found dominant for pseudo-pelletierine. All monosubstituted isotopic species (13C, 15N and 18O) were identified for the axial conformer, leading to an accurate determination of the effective and substitution structures. An estimation of conformational populations was derived from relative intensities. The experimental results will be compared with ab initio (MP2) and DFT (M06-2X, B3LYP) calculations. E. J. Cocinero, A. Lesarri, P. Écija, J.-U. Grabow, J. A. Fernández, F. Castaño, Phys. Chem. Chem. Phys. 2010, 49, 4503 P. Écija, E. J. Cocinero, A. Lesarri, F. J. Basterretxea, J. A. Fernández, F. Castaño, Chem. Phys. Chem. 2013, 14, 1830 P. Écija, M. Vallejo-Lopez, I. Uriarte, F. J. Basterretxea, A. Lesarri, J. A. Fernández, E. J. Cocinero, submitted 2016

Mixtures of 3,4-methylenedioxymethamphetamine (ecstasy) and its major human metabolites act additively to induce significant toxicity to liver cells when combined at low, non-cytotoxic concentrations.

PubMed

da Silva, Diana Dias; Silva, Elisabete; Carvalho, Félix; Carmo, Helena

2014-06-01

Hepatic injury after 3,4-methylenedioxymethamphetamine (MDMA; ecstasy) intoxications is highly unpredictable and does not seem to correlate with either dosage or frequency of use. The mechanisms involved include the drug metabolic bioactivation and the hyperthermic state of the liver triggered by its thermogenic action and exacerbated by the environmental circumstances of abuse at hot and crowded venues. We became interested in understanding the interaction between ecstasy and its metabolites generated in vivo as users are always exposed to mixtures of parent drug and metabolites. With this purpose, Hep G2 cells were incubated with MDMA and its main human metabolites methylenedioxyamphetamine (MDA), α-methyldopamine (α-MeDA) and N-methyl-α-methyldopamine (N-Me-α-MeDA), individually and in mixture (drugs combined in proportion to their individual EC01 ), at normal (37 °C) and hyperthermic (40.5 °C) conditions. After 48 h, viability was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Extensive concentration-response analysis was performed with single drugs and the parameters of the individual non-linear logit fits were used to predict joint effects using the well-founded models of concentration addition (CA) and independent action (IA). Experimental testing revealed that mixture effects on cell viability conformed to CA, for both temperature settings. Additionally, substantial combination effects were attained even when each substance was present at concentrations that individually produced unnoticeable effects. Hyperthermic incubations dramatically increased the toxicity of the tested drug and metabolites, both individually and combined. These outcomes suggest that MDMA metabolism has hazard implications to liver cells even when metabolites are found in low concentrations, as they contribute additively to the overall toxic effect of MDMA. Copyright © 2013 John Wiley & Sons, Ltd.

Quantification of MDMA and MDA in abusers' hair samples by semi-micro column HPLC with fluorescence detection.

PubMed

Nakamura, Shinichi; Tomita, Mamoru; Wada, Mitsuhiro; Chung, Heesun; Kuroda, Naotaka; Nakashima, Kenichiro

2006-01-01

A sensitive semi-micro column high-performance liquid chromatography with fluorescence detection method was developed for the determination of 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), methamphetamine (MP) and amphetamine (AP) in human hair. 4-(4,5-Diphenyl-1H-imidazol-2-yl)benzoyl chloride (DIB-Cl) and 1-methyl-3-phenylpropylamine were used as labeling reagent and internal standard, respectively. These drugs were extracted from hair into 5% trifluoroacetic acid in methanol, and fluorescent labeled with DIB-Cl. The separation of DIB-derivatives was achieved on a reversed-phase semi-micro ODS column with an acetonitrile-methanol-water (30:40:30, v/v/v%) mixture as a mobile phase. The limits of detection at a signal-to-noise ratio of 3 for MDMA, MDA, MP and AP were 0.25, 0.15, 0.25 and 0.19 ng/mg, respectively. Precision of intra- and inter-day assay as the relative standard deviation were in the range 1.5-6.8% (n = 5) and 2.7-4.7% (n = 5), respectively. The proposed method was highly sensitive and able to detect MDMA and its related compounds in small amounts of hair sample, and could be applied to quantification of six abusers' hair samples. Copyright 2006 John Wiley & Sons, Ltd.

Transferrin-Conjugated SNALPs Encapsulating 2′-O-Methylated miR-34a for the Treatment of Multiple Myeloma

PubMed Central

Scognamiglio, Immacolata; Di Martino, Maria Teresa; Campani, Virginia; Virgilio, Antonella; Galeone, Aldo; Gullà, Annamaria; Gallo Cantafio, Maria Eugenia; Tagliaferri, Pierosandro; Tassone, Pierfrancesco; Caraglia, Michele

2014-01-01

Stable nucleic acid lipid vesicles (SNALPs) encapsulating miR-34a to treat multiple myeloma (MM) were developed. Wild type or completely 2′-O-methylated (OMet) MiR-34a was used in this study. Moreover, SNALPs were conjugated with transferrin (Tf) in order to target MM cells overexpressing transferrin receptors (TfRs). The type of miR-34a chemical backbone did not significantly affect the characteristics of SNALPs in terms of mean size, polydispersity index, and zeta potential, while the encapsulation of an OMet miR-34a resulted in a significant increase of miRNA encapsulation into the SNALPs. On the other hand, the chemical conjugation of SNALPs with Tf resulted in a significant decrease of the zeta potential, while size characteristics and miR-34a encapsulation into SNALPs were not significantly affected. In an experimental model of MM, all the animals treated with SNALPs encapsulating miR-34a showed a significant inhibition of the tumor growth. However, the use of SNALPs conjugated with Tf and encapsulating OMet miR-34a resulted in the highest increase of mice survival. These results may represent the proof of concept for the use of SNALPs encapsulating miR-34a for the treatment of MM. PMID:24683542

Bioconversion of 6-(N-methyl-N-phenyl)aminomethyl androstane steroids by Nocardioides simplex.

PubMed

Sukhodolskaya, Galina; Fokina, Victoria; Shutov, Andrei; Nikolayeva, Vera; Savinova, Tatiana; Grishin, Yuri; Kazantsev, Alexey; Lukashev, Nikolay; Donova, Marina

2017-02-01

The newly synthesized (α/β)-diastereomers of 6-(N-methyl-N-phenyl)aminomethylandrost-4-ene-3,17-dione (5) and 6-(N-methyl-N-phenyl)aminomethylandrost-4-en-17β-ol-3-one (6) were firstly investigated as substrates for the whole cells of Nocardioides simplex VKM Ac-2033D in comparison with their unsubstituted analogs, - androst-4-ene-3,17-dione (1) and androst-4-en-17β-ol-3-one (2). 1(2)-Dehydroderivatives were identified as the major bioconversion products from all the substrates tested. When using the mixtures of (α/β)-stereoisomers of 5 and 6 as the substrates, only β-stereoisomers of the corresponding 1,4-diene-steroids were formed. Along with 1(2)-dehydrogenation, N. simplex VKM Ac-2033D promoted oxidation of the hydroxyl group at C-17 position of 6: both 6(α) and 6(β) were transformed to the corresponding 17-keto derivatives. No steroid core destruction was observed during the conversion of the 6-substituted androstanes 5 and 6, while it was significant when 1 or 2 was used as the substrate. The results suggested high potentials of N. simplex VKM Ac-2033D for the generation of novel 1(2)-dehydroanalogs. Copyright © 2016 Elsevier Inc. All rights reserved.

DNA precursor pool: a significant target for N-methyl-N-nitrosourea in C3H/10T1/2 clone 8 cells.

PubMed Central

Topal, M D; Baker, M S

1982-01-01

Synchronized C3H/10T1/2 clone 8 cells were treated in vitro with a nontoxic dose of N-methyl-N-nitrosourea during their S phase. Chromatographic isolation of the deoxyribonucleotide DNA precursor pool and measurement of the precursor content per cell showed that a nucleic acid residue in the precursor pool is 190-13,000 times more susceptible to methylation than a residue in the DNA duplex, depending on the site of methylation. This conclusion comes from measurements indicating that, for example, the N-1 position of adenine in dATP is 6.3 times more methylated than the same position in the DNA, even though the adenine content of the pool is only a fraction (0.0005) of the adenine content of the DNA helix. The comparative susceptibility between pool and DNA was found to vary with the site of methylation in the order the N-1 position of adenine greater than phosphate greater than the N-3 position of adenine greater than the O6 position of guanine greater than the N-7 position of guanine. The significance of these results for chemical mutagenesis and carcinogenesis is discussed. PMID:6954535

Synthesis and characterization of 3-acetoxy-2-methyl-N-(phenyl)benzamide and 3-acetoxy-2-methyl-N-(4- methylphenyl)benzamide

NASA Astrophysics Data System (ADS)

Kırca, Başak Koşar; Çakmak, Şükriye; Kütük, Halil; Odabaşoğlu, Mustafa; Büyükgüngör, Orhan

2018-01-01

This study treats about two successfully synthesized secondary amide compounds 3-Acetoxy-2-methyl-N-(phenyl)benzamide, I and 3-Acetoxy-2-methyl-N-(4-methylphenyl)benzamide, II. Compounds were characterized by FTIR, 1H NMR, 13C NMR and X-ray single crystal diffraction analysis techniques. Single crystal X-ray diffraction analyses show that while I crystallized in the orthorhombic system with space group Pbca, II crystallized in the triclinic system with space group P-1 and the asymmetric unit of II consists of two crystallographically independent molecules. Lattice constants are a = 7.9713 (3) Å, b = 9.5059 (3) Å, c = 37.1762 (2) Å, Z = 8 for I and a = 7.5579 (8) Å, b = 8.8601 (8) Å, c = 23.363 (3) Å, α = 97.011 (9) °, β = 96.932 (9)°, γ = 90.051 (8)°, Z = 4 for II. Crystallographic studies also show that the supramolecular structures were stabilized by intramolecular, intermolecular hydrogen bonds and Csbnd H … π interactions for both compounds. Characteristic amide bonds were observed in IR and NMR spectra.

Induction of glandular stomach cancers in Helicobacter pylori-sensitive Mongolian gerbils treated with N-methyl-N-nitrosourea and N-methyl-N'-nitro-N-nitrosoguanidine in drinking water.

PubMed

Tatematsu, M; Yamamoto, M; Shimizu, N; Yoshikawa, A; Fukami, H; Kaminishi, M; Oohara, T; Sugiyama, A; Ikeno, T

1998-02-01

An animal model of stomach carcinogenesis was established using Mongolian gerbils with N-methyl-N-nitrosourea (MNU) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) as the carcinogens. In addition, the sensitivity of these gerbils to Helicobacter pylori (H. pylori) was confirmed. One hundred and sixty specific pathogen-free male MGS/Sea animals, 7 weeks old, were treated with MNU in the drinking water (30 ppm for alternate weeks to give 10 weeks exposure, or 10 ppm or 3 ppm for 20 weeks continuous exposure), or given MNNG in the drinking water at 400 ppm or 200 ppm for 20 weeks, or orally inoculated with ATCC43504 H. pylori (1.7 x 10(8) CFUs/animal). Adenocarcinomas in the glandular stomach were found in 2 out of 12 effective animals (2/ 12) treated with 30 ppm MNU at week 20, although all were dead or moribund by week 30 due to MNU toxicity. At week 50, the incidences of gastric adenocarcinomas in groups treated with 10 ppm MNU, 3 ppm MNU, 400 ppm MNNG, and 200 ppm MNNG were 2/21 (9.5%), 1/23 (4.3%), 7/ 11 (63.6%), and 1/10 (10.0%). The lesions were generally well differentiated, although poorly differentiated adenocarcinoma was also found in a single gerbil in each of the 10 ppm MNU and 400 ppm MNNG groups. In control animals no tumors were found. In the infection study, the animals were killed at week 20, and H. pylori was detected in all cases, causing multiple erosions with marked inflammatory cell infiltration in the lamina propria and submucosa, and frequent formation of lymphoid follicles. Thus, MNU and MNNG in the drinking water induced neoplastic lesions in the glandular stomach epithelium of H. pylori-sensitive gerbils.

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.

N-Methyl Inversion and Accurate Equilibrium Structures in Alkaloids: Pseudopelletierine.

PubMed

Vallejo-López, Montserrat; Écija, Patricia; Vogt, Natalja; Demaison, Jean; Lesarri, Alberto; Basterretxea, Francisco J; Cocinero, Emilio J

2017-11-21

A rotational spectroscopy investigation has resolved the conformational equilibrium and structural properties of the alkaloid pseudopelletierine. Two different conformers, which originate from inversion of the N-methyl group from an axial to an equatorial position, have been unambiguously identified in the gas phase, and nine independent isotopologues have been recorded by Fourier-transform microwave spectroscopy in a jet expansion. Both conformers share a chair-chair configuration of the two bridged six-membered rings. The conformational equilibrium is displaced towards the axial form, with a relative population in the supersonic jet of N axial /N equatorial ≈2/1. An accurate equilibrium structure has been determined by using the semiexperimental mixed-estimation method and alternatively computed by quantum-chemical methods up to the coupled-cluster level of theory. A comparison with the N-methyl inversion equilibria in related tropanes is also presented. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Promoter CpG methylation of multiple genes in pituitary adenomas: frequent involvement of caspase-8.

PubMed

Bello, M Josefa; De Campos, Jose M; Isla, Alberto; Casartelli, Cacilda; Rey, Juan A

2006-02-01

The epigenetic changes in pituitary adenomas were identified by evaluating the methylation status of nine genes (RB1, p14(ARF), p16(INK4a), p73, TIMP-3, MGMT, DAPK, THBS1 and caspase-8) in a series of 35 tumours using methylation-specific PCR analysis plus sequencing. The series included non-functional adenomas (n=23), prolactinomas (n=6), prolactinoma plus thyroid-stimulating hormone adenoma (n=1), growth hormone adenomas (n=4), and adrenocorticotropic adenoma (n=1). All of the tumours had methylation of at least one of these genes and 40% of samples (14 of 35) displayed concurrent methylation of at least three genes. The frequencies of aberrant methylation were: 20% for RB1, 17% for p14(ARF), 34% for p16(INK4a), 29% for p73, 11% for TIMP-3, 23% for MGMT, 6% for DAPK, 43% for THBS1 and 54% for caspase-8. No aberrant methylation was observed in two non-malignant pituitary samples from healthy controls. Although some differences in the frequency of gene methylation between functional and non-functional adenomas were detected, these differences did not reach statistical significance. Our results suggest that promoter methylation is a frequent event in pituitary adenoma tumourigenesis, a process in which inactivation of apoptosis-related genes (DAPK, caspase-8) might play a key role.

Insight into the theoretical and experimental studies of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone N(4)-methyl-N(4)- phenylthiosemicarbazone - A potential NLO material

NASA Astrophysics Data System (ADS)

Sangeetha, K. G.; Aravindakshan, K. K.; Safna Hussan, K. P.

2017-12-01

The synthesis, geometrical parameters, spectroscopic studies, optimised molecular structure, vibrational analysis, Mullikan population analysis, MEP, NBO, frontier molecular orbitals and NLO effects of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone N-(4)-methyl-N-(4)-phenylthiosemicarbazone, C25H23N5OS (L1) have been communicated in this paper. A combined experimental and theoretical approach was used to explore the structure and properties of the compound. For computational studies, Gaussian 09 program was used. Starting geometry of molecule was taken from X-ray refinement data and has been optimized by using DFT (B3LYP) method with the 6-31+G (d, p) basis sets. NBO analysis gave insight into the strongly delocalized structure, responsible for the nonlinearity and hence the stability of the molecule. Frontier molecular orbitals have been defined to forecast the global reactivity descriptors of L1. The computed first-order hyperpolarizability (β) of the compound is 2 times higher than that of urea and this account for its nonlinear optical property. Simultaneously, a molecular docking study of the compound was performed using GLIDE Program. For this, three biological enzymes, histone deacetylase, ribonucleotide reductase and DNA methyl transferase, were selected as receptor molecules.

TOXICITY OF TETRYL (N-METHYL-N,2,4,6-TETRANITROANILINE) IN F344 RATS

EPA Science Inventory

The toxicity of tetryl (N-methyl-N,2,4,6-tetranitroaniline) in male and female F344 rats was evaluated after adminstration in the diet for 14 or 90 days. The 14-day study diet concentrations used were 0, 500, 1250, 2000, 2500, and 5000 ppm; the 90-day study diet concentrations we...

DNA methylation of ESR-1 and N-33 in colorectal mucosa of patients with ulcerative colitis (UC).

PubMed

Arasaradnam, Ramesh P; Khoo, Kevin; Bradburn, Mike; Mathers, John C; Kelly, Seamus B

2010-07-01

Epigenetic marking such as DNA methylation influence gene transcription and chromosomal stability and may also be affected by environmental exposures. Few studies exist on alteration in DNA methylation profiles (genomic and gene specific methylation) in patients with Ulcerative Colitis (UC) and no studies exist that assess its relationship with lifestyle exposures. The methylation level of both ESR-1 and N-33 genes were significantly higher in UC subjects compared with controls (7.9% vs. 5.9%; p = 0.015 and 66% vs. 9.3%; p < 0.001 respectively). There was no detectable difference in global DNA methylation between patients with UC and age and sex matched controls. No associations between indices of DNA methylation and anthropometric measures or smoking patterns were detected. To assess genomic methylation and promoter methylation of the ESR-1 (oestrogen receptor-1) and N-33 (tumor suppressor candidate-3) genes in the macroscopically normal mucosa of UC patients as well as to investigate effects of anthropometric and lifestyle exposures on DNA methylation. Sixty eight subjects were recruited (24 UC and 44 age and sex matched controls). Colorectal mucosal biopsies were obtained and DNA was extracted. Genomic DNA methylation was quantified using the tritium-labelled cytosine extension assay (3[H] dCTP) while gene specific methylation was quantified using the COBRA method. For the first time, we have shown increased methylation in the promoter regions of the putative tumor suppressor gene N-33 in macroscopically normal mucosa of patients with UC. In addition, we have confirmed that methylation of ESR-1 promoter is higher in UC patients compared with age and sex matched controls. These findings suggest that inactivation through methylation of the putative tumor suppressor genes N-33 and ESR-1 may not be associated with colorectal carcinogenesis in UC.

MeDIP-seq and nCpG analyses illuminate sexually dimorphic methylation of gonadal development genes with high historic methylation in turtle hatchlings with temperature-dependent sex determination.

PubMed

Radhakrishnan, Srihari; Literman, Robert; Mizoguchi, Beatriz; Valenzuela, Nicole

2017-01-01

DNA methylation alters gene expression but not DNA sequence and mediates some cases of phenotypic plasticity. Temperature-dependent sex determination (TSD) epitomizes phenotypic plasticity where environmental temperature drives embryonic sexual fate, as occurs commonly in turtles. Importantly, the temperature-specific transcription of two genes underlying gonadal differentiation is known to be induced by differential methylation in TSD fish, turtle and alligator. Yet, how extensive is the link between DNA methylation and TSD remains unclear. Here we test for broad differences in genome-wide DNA methylation between male and female hatchling gonads of the TSD painted turtle Chrysemys picta using methyl DNA immunoprecipitation sequencing, to identify differentially methylated candidates for future study. We also examine the genome-wide nCpG distribution (which affects DNA methylation) in painted turtles and test for historic methylation in genes regulating vertebrate gonadogenesis. Turtle global methylation was consistent with other vertebrates (57% of the genome, 78% of all CpG dinucleotides). Numerous genes predicted to regulate turtle gonadogenesis exhibited sex-specific methylation and were proximal to methylated repeats. nCpG distribution predicted actual turtle DNA methylation and was bimodal in gene promoters (as other vertebrates) and introns (unlike other vertebrates). Differentially methylated genes, including regulators of sexual development, had lower nCpG content indicative of higher historic methylation. Ours is the first evidence suggesting that sexually dimorphic DNA methylation is pervasive in turtle gonads (perhaps mediated by repeat methylation) and that it targets numerous regulators of gonadal development, consistent with the hypothesis that it may regulate thermosensitive transcription in TSD vertebrates. However, further research during embryogenesis will help test this hypothesis and the alternative that instead, most differential methylation

Reduced DNA repair in mouse satellite DNA after treatment with methylmethanesulfonate, and N-methyl-N-nitrosourea.

PubMed Central

Bodell, W J; Banerjee, M R

1976-01-01

We have measured DNA repair in mouse satellite and main band DNA as resolved by Ag+-Cs2SO4 centrifugation in response to treatment with the alkylating agents, methyl methanesulfonate, and N-methyl-N-nitrosourea. We find that there is a statistically significant lower incorporation of 3H-Tdr into the satellite DNA as compared to the main band at varying periods after treatment with the alkylating agents. This suggests a reduced repair activity in the satellite DNA. We have measured the extent of binding of 14C-methyl methanesulfonate to the satellite, and main band DNA, and no difference in binding was observed, indicating that the reduced repair activity of satellite DNA is not due to a difference in binding of alkylating agents. We believe that the reduced incorporation of 3H-Tdr into satellite DNA may be due to its location in the condensed chromatin fraction. PMID:184436

Design and in vitro activities of N-alkyl-N-[(8-R-2,2-dimethyl-2H-chromen-6-yl)methyl]heteroarylsulfonamides, novel small molecule Hypoxia Inducible Factor-1 (HIF-1) pathway inhibitors and anti-cancer agents

PubMed Central

Mun, Jiyoung; Jabbar, Adnan Abdul; Devi, Narra Sarojini; Yin, Shaoman; Wang, Yingzhe; Tan, Chalet; Culver, Deborah; Snyder, James P.; Van Meir, Erwin G.; Goodman, Mark M.

2013-01-01

The Hypoxia Inducible Factor (HIF) pathway is an attractive target for cancer as it controls tumor adaptation to growth under hypoxia and mediates chemo- and radiation resistance. We previously discovered 3,4-dimethoxy-N-[(2,2-dimethyl-2H-chromen-6-yl)methyl]-N-phenylbenzenesulfonamide, as a novel small molecule HIF-1 pathway inhibitor in a high-throughput cell-based assay, but its in vivo delivery is hampered by poor aqueous solubility (0.009 μM in water; logP7.4: 3.7). Here we describe the synthesis of twelve N-alkyl-N-[(8-R-2,2-dimethyl-2H-chromen-6-yl)methyl]heteroarylsulfonamides, which were designed to possess optimal lipophilicities and aqueous solubilities by in silico calculations. Experimental logP7.4 values of 8 of the 12 new analogs ranged from 1.2 ∼ 3.1. Aqueous solubilities of 3 analogs were measured, among which the most soluble N-[(8-methoxy-2,2-dimethyl-2H-chromen-6-yl)methyl]-N-(propan-2-yl)pyridine-2-sulfonamide had an aqueous solubility of 80 μM, e.g. a solubility improvement of ∼9,000-fold. The pharmacological optimization had minimal impact on drug efficacy as the compounds retained IC50 values at or below 5 μM in our HIF-dependent reporter assay. PMID:22746274

N-mustard analogs of S-adenosyl-L-methionine as biochemical probes of protein arginine methylation.

PubMed

Hymbaugh Bergman, Sarah J; Comstock, Lindsay R

2015-08-01

Nucleosomes, the fundamental building blocks of eukaryotic chromatin, undergo post-synthetic modifications and play a major role in the regulation of transcriptional processes. Combinations of these modifications, including methylation, regulate chromatin structure, determining its different functional states and playing a central role in differentiation. The biological significance of cellular methylation, particularly on chromatin, is widely recognized, yet we know little about the mechanisms that link biological methylation events. To characterize and fully understand protein methylation, we describe here novel N-mustard analogs of S-adenosyl-l-methionine (SAM) as biochemical tools to better understand protein arginine methylation events using protein arginine methyltransferase 1 (PRMT1). Specifically, azide- and alkyne-functionalized N-mustard analogs serve as cofactor mimics of SAM and are enzymatically transferred to a model peptide substrate in a PRMT1-dependent fashion. Once incorporated, the resulting alkynes and azides can be modified through chemoselective ligations, including click chemistry and the Staudinger ligation. These results readily demonstrate the feasibility of utilizing N-mustard analogs as biochemical tools to site-specifically label substrates of PRMT1 and serve as an alternative approach to study protein methylation events. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

4-(Di­methyl­amino)­pyridinium trichlorido[4-(di­methyl­amino)­pyridine-κN]cobaltate(II)

PubMed Central

Guenifa, Fatiha; Hadjadj, Nasreddine; Zeghouan, Ouahida; Bendjeddou, Lamia; Merazig, Hocine

2013-01-01

In the anion of the title compound, (C7H11N2)[CoCl3(C7H10N2)], the CoII ion is coordinated by one N atom from a 4-(di­methyl­amino)­pyridine (DMAP) ligand and three Cl atoms, forming a CoNCl3 polyhedron with a distorted tetra­hedral geometry. In the crystal, cations and anions are linked via weak N—H⋯Cl and C—H⋯Cl hydrogen bonds. Double layers of complex anions stack along the b- axis direction, which alternate with double layers of 4-(di­methyl­amino)-pyridinium cations. PMID:24046560

Preparation, electrochemical and spectral properties of free-base and manganese N-methyl-pyridylethynyl porphyrins.

PubMed

Lin, Ching-Yao; Chen, Yen-Chuan; Yao, Chi-Wen; Huang, Sung-Chou; Cheng, Yi-Hui

2008-02-14

Two series of free-base and manganese N-methyl-pyridylethynyl-5,15-biphenyl porphyrins were synthesized, and their UV-Visible, electrochemical and spectro-electrochemical properties were studied. Cyclic voltammetry experiments showed positive shifts in the reduction potentials and the UV-Visible spectra showed significant red-shifts in the absorption wavelengths of these porphyrins, indicating the effects of N-methyl-pyridylethynyl substituents.

Investigations on the synthesis and pharmacological properties of 4-alkoxy-2-[2-hydroxy-3-(4-aryl-1-piperazinyl)propyl]-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones.

PubMed

Sladowska, Helena; Filipek, Barbara; Szkatuła, Dominika; Sabiniarz, Aleksandra; Kardasz, Małgorzata; Potoczek, Joanna; Sieklucka-Dziuba, Maria; Rajtar, Grazyna; Kleinrok, Zdzisław; Lis, Tadeusz

2002-11-01

Synthesis of 2-[2-hydroxy-3-(4-aryl-1-piperazinyl)propyl] derivatives of 4-alkoxy-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones (8-12) is described. The chlorides used in the above synthesis can exist in two isomeric forms: chain (18-20) and cyclic (19a, 20a). The compounds 8-12 exhibited potent analgesic activity which was superior than that of acetylsalicylic acid in two different tests. Most of the investigated imides suppressed significantly spontaneous locomotor activity in mice.

Steric control of the asymmetric synthesis of N-substituted 2-methyl-4-piperidones

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

Grishina, G.V.; Potapov, V.M.; Abdulganeeva, S.A.

Transmission of the iodomethylate of 1,2-dimethyl-4-piperidone by (S)-sec-butylamine gives 1-(S-sec-butyl)-2S-methyl-4-piperidone in 33% optical yield while transamination by (S)-1-methyl-2-phenylethylamine gives a 1:1 diastereomeric mixture of 1-(1-methyl-2-phenylethyl)-2-methyl-4-piperidone. The decrease in the optical yield is related to the facile opening of the piperidone ring at the C-N bond with subsequent recyclization. The /sup 13/C NMR data indicate that all the diastereomers of the 4-piperidones obtained are in the chain conformation with predominantly equatorial orientation of the methyl group at C/sub (2)/. The chiral optical properties were studied and the absolution configurations of the 4-piperidones obtained were established.

40 CFR 721.1000 - Benzenamine, 3-chloro-2,6-dinitro-N,N-dipropyl-4-(tri-fluoro-methyl)-.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Benzenamine, 3-chloro-2,6-dinitro-N,N-dipropyl-4-(tri-fluoro-methyl)-. 721.1000 Section 721.1000 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.1000 Benzenamine, 3-chloro-2,6-dinitro-N,N...

DOSE-RESPONSE MODELING FOR THE ASSESSMENT OF CUMULATIVE RISK DUE TO EXPOSURE TO N-METHYL CARBAMATE PESTICIDES

EPA Science Inventory

The US EPAs N-Methyl Carbamate Cumulative Risk Assessment (NMCRA) assesses the effect on acetylcholine esterase (AChE) activity of exposure to 10 N-methyl carbamate (NMC) pesticides through dietary, drinking water, and residential exposures.

Sprague-Dawley rats display sex-linked differences in the pharmacokinetics of 3,4-methylenedioxymethamphetamine (MDMA) and its metabolite 3,4-methylenedioxyamphetamine (MDA)

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

Fonsart, Julien, E-mail: julien.fonsart@lrb.aphp.f; CNRS, UMR 7157, Paris F-75006; INSERM, U705, Paris F-75006

The use of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) has increased in recent years; it can lead to life-threatening hyperthermia and serotonin syndrome. Human and rodent males appear to be more sensitive to acute toxicity than are females. MDMA is metabolized to five main metabolites by the enzymes CYP1A2, CYP2D and COMT. Little is presently known about sex-dependent differences in the pharmacokinetics of MDMA and its metabolites. We therefore analyzed MDMA disposition in male and female rats by measuring the plasma and urine concentrations of MDMA and its metabolites using a validated LC-MS method. MDA AUC{sub last} and C{sub max} were 1.6- tomore » 1.7-fold higher in males than in females given MDMA (5 mg/kg sc), while HMMA C{sub max} and AUC{sub last} were 3.2- and 3.5-fold higher, respectively. MDMA renal clearance was 1.26-fold higher in males, and that of MDA was 2.2-fold higher. MDMA AUC{sub last} and t{sub 1/2} were 50% higher in females given MDMA (1 mg/kg iv). MDA C{sub max} and AUC{sub last} were 75-82% higher in males, with a 2.8-fold higher metabolic index. Finally, the AUC{sub last} of MDA was 0.73-fold lower in males given 1 mg/kg iv MDA. The volumes of distribution of MDMA and MDA at steady-state were similar in the two sexes. These data strongly suggest that differences in the N-demethylation of MDMA to MDA are major influences on the MDMA and MDA pharmacokinetics in male and female rats. Hence, males are exposed to significantly more toxic MDA, which could explain previously reported sexual dysmorphism in the acute effects and toxicity of MDMA in rats.« less

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.

Increased levels of N(ε)- Carboxy methyl lysine (N(ε)-CML) are associated with topographic alterations in retinal pigment epithelium: A preliminary study.

PubMed

Mishra, Nibha; Saxena, Sandeep; Ruia, Surabhi; Prasad, Senthamizh; Singh, Vinita; Khanna, Vinay; Staffa, Robert; Gaspar, Ludovit; Kruzliak, Peter

2016-07-01

To evaluate the association of serum levels of N(ε)- Carboxy methyl lysine (N(ε)-CML), an advanced glycation end product with topographic alterations in retinal pigment epithelium (RPE) in diabetic retinopathy on spectral domain optical coherence tomography (SD-OCT). Consecutive cases of type 2 diabetes mellitus with no retinopathy (n=20); non-proliferative diabetic retinopathy (n=20); proliferative diabetic retinopathy (n=20) and healthy controls (n=20) between the ages of 40 and 65years were included. RPE alterations were graded on segmentation map of SD-OCT: grade 0, No RPE alterations; grade 1, RPE alterations in up to two quadrants and grade 2, RPE alterations in more than two quadrants. Serum level of N(ε)-CML and glycated hemoglobin (HbA1c) was analyzed using the standard protocol. Statistical analysis was done. Significant increase in N(ε)-CML was observed with increased severity of diabetic retinopathy (F=34.1; p<0.0001). Fisher exact test revealed significant increase in grades of RPE alterations with increased severity of diabetic retinopathy (p<0.001). Univariate ordinal regression analysis was done to calculate the risk of progression in grades of RPE alteration with individual changes in variables like duration of diabetes (odds ratio=1.37; p=0.001), HbA1c (odds ratio=1.37; p=0.002) and Nε-CML (odds ratio=1.37; p<0.0001). Multivariate ordinal regression analysis for predicting progression in grades of RPE alteration revealed Nε-CML to be an independent predictor of increase in grades of RPE alteration (adjusted odds ratio=1.07; p<0.01) when duration of diabetes and HbA1c were held constant. Increase in serum levels of N(ε)- Carboxy methyl lysine is significantly associated with topographic alterations in RPE. Grades of RPE alteration increase significantly with increased severity of diabetic retinopathy. Copyright © 2016 Elsevier Inc. All rights reserved.

COMPARISON OF ACUTE NEUROBEHAVIORAL EFFECTS OF N-METHYL CARBAMATE INSECTICIDES.

EPA Science Inventory

The acute neurobehavioral and cholinesterase (ChE)-inhibiting effects of N-methyl carbamate insecticides have not been systematically compared. We evaluated five carbamates - carbaryl (CB), propoxur (PP), oxamyl (OM), methomyl (MM), and methiocarb (MC). Adult male Long-Evans ra...

Radiosynthesis and radiopharmacological evaluation of [N-methyl-11C]Org 34850 as a glucocorticoid receptor (GR)-binding radiotracer.

PubMed

Wuest, Frank; Kniess, Torsten; Henry, Brian; Peeters, Bernardus W M M; Wiegerinck, Peter H G; Pietzsch, Jens; Bergmann, Ralf

2009-02-01

The radiosynthesis of [N-methyl-(11)C]Org 34850 as a potential brain glucocorticoid receptor (GR)-binding radiotracer is described. The radiosynthesis was accomplished via N-methylation of the corresponding desmethyl precursor with [(11)C]methyl triflate in a remotely controlled synthesis module to give the desired compound in a radiochemical yield of 23+/-5% (decay-corrected, based upon [(11)C]CO(2)) at a specific activity of 47+/-12 GBq/micromol (n=15) at the end-of-synthesis (EOS). The radiochemical purity after semi-preparative HPLC purification exceeded 95%. The total synthesis time was 35-40 min after end-of-bombardment (EOB). The radiotracer is rapidly metabolized in rat plasma leading to the formation of two more hydrophilic metabolites as the major metabolites. Radiopharmacological evaluation involving biodistribution and small animal PET imaging in normal Wistar rats showed that the compound [N-methyl-(11)C]Org 34850 is not able to sufficiently penetrate the blood-brain barrier. Therefore, compound [N-methyl-(11)C]Org 34850 seems not to be a suitable PET radiotracer for imaging rat brain GRs. However, involvement of Pgp or species differences requires further clarification to establish whether the radiotracer [N-methyl-(11)C]Org 34850 may still represent a suitable candidate for imaging GRs in humans.

DNA methylation profiling identifies global methylation differences and markers of adrenocortical tumors.

PubMed

Rechache, Nesrin S; Wang, Yonghong; Stevenson, Holly S; Killian, J Keith; Edelman, Daniel C; Merino, Maria; Zhang, Lisa; Nilubol, Naris; Stratakis, Constantine A; Meltzer, Paul S; Kebebew, Electron

2012-06-01

It is not known whether there are any DNA methylation alterations in adrenocortical tumors. The objective of the study was to determine the methylation profile of normal adrenal cortex and benign and malignant adrenocortical tumors. Genome-wide methylation status of CpG regions were determined in normal (n = 19), benign (n = 48), primary malignant (n = 8), and metastatic malignant (n = 12) adrenocortical tissue samples. An integrated analysis of genome-wide methylation and mRNA expression in benign vs. malignant adrenocortical tissue samples was also performed. Methylation profiling revealed the following: 1) that methylation patterns were distinctly different and could distinguish normal, benign, primary malignant, and metastatic tissue samples; 2) that malignant samples have global hypomethylation; and 3) that the methylation of CpG regions are different in benign adrenocortical tumors by functional status. Normal compared with benign samples had the least amount of methylation differences, whereas normal compared with primary and metastatic adrenocortical carcinoma samples had the greatest variability in methylation (adjusted P ≤ 0.01). Of 215 down-regulated genes (≥2-fold, adjusted P ≤ 0.05) in malignant primary adrenocortical tumor samples, 52 of these genes were also hypermethylated. Malignant adrenocortical tumors are globally hypomethylated as compared with normal and benign tumors. Methylation profile differences may accurately distinguish between primary benign and malignant adrenocortical tumors. Several differentially methylated sites are associated with genes known to be dysregulated in malignant adrenocortical tumors.

Methyl-3,4-dihydroxybenzoate and 9-10-dihydrophenanthrene-2,4,7-triol two phenolic compounds from Dioscorea alata L. and their antioxidant activity

NASA Astrophysics Data System (ADS)

Aminah, N. S.; Yulvia, A.; Tanjung, M.

2017-09-01

Two phenolic compounds namely: methyl-3,4-dihydroxybenzoate (1) and 9,10-dihydrophenanthrene-2,4,7-triol (2) had been isolated for the first time from the tuber of Dioscorea alata L. The extraction of two compounds were done by maceration method using methanol as solvent, followed by partition with n-hexane and ethyl acetate. The ethyl acetate extract was separated and purified using various chromatographic techniques yielded pure compounds. The structure of isolated compounds were determined based on spectroscopic data, including UV-Vis, 1D and 2D NMR spectra. Compounds (1), (2) and ascorbic acid as a comparator were evaluated for their antioxidant properties against DPPH, showing their IC50 were 9,41 ± 0,08; 23,52 ± 0,05; and 10,95 ± 0,08 ppm, respectively.

Structures and stabilities of Al(n) (+), Al(n), and Al(n) (-) (n=13-34) clusters.

PubMed

Aguado, Andrés; López, José M

2009-02-14

Putative global minima of neutral (Al(n)) and singly charged (Al(n) (+) and Al(n) (-)) aluminum clusters with n=13-34 have been located from first-principles density functional theory structural optimizations. The calculations include spin polarization and employ the generalized gradient approximation of Perdew, Burke, and Ernzerhof to describe exchange-correlation electronic effects. Our results show that icosahedral growth dominates the structures of aluminum clusters for n=13-22. For n=23-34, there is a strong competition between decahedral structures, relaxed fragments of a fcc crystalline lattice (some of them including stacking faults), and hexagonal prismatic structures. For such small cluster sizes, there is no evidence yet for a clear establishment of the fcc atomic packing prevalent in bulk aluminum. The global minimum structure for a given number of atoms depends significantly on the cluster charge for most cluster sizes. An explicit comparison is made with previous theoretical results in the range n=13-30: for n=19, 22, 24, 25, 26, 29, 30 we locate a lower energy structure than previously reported. Sizes n=32, 33 are studied here for the first time by an ab initio technique.

Efficient and Selective N-Methylation of Nitroarenes under Mild Reaction Conditions.

PubMed

Pedrajas, Elena; Sorribes, Iván; Guillamón, Eva; Junge, Kathrin; Beller, Matthias; Llusar, Rosa

2017-09-21

Herein, we report a straightforward protocol for the preparation of N,N-dimethylated amines from readily available nitro starting materials using formic acid as a renewable C 1 source and silanes as reducing agents. This tandem process is efficiently accomplished in the presence of a cubane-type Mo 3 PtS 4 catalyst. For the preparation of the novel [Mo 3 Pt(PPh 3 )S 4 Cl 3 (dmen) 3 ] + (3 + ) (dmen: N,N'-dimethylethylenediamine) compound we have followed a [3+1] building block strategy starting from the trinuclear [Mo 3 S 4 Cl 3 (dmen) 3 ] + (1 + ) and Pt(PPh 3 ) 4 (2) complexes. The heterobimetallic 3 + cation preserves the main structural features of its 1 + cluster precursor. Interestingly, this catalytic protocol operates at room temperature with high chemoselectivity when the 3 + catalyst co-exists with its trinuclear 1 + precursor. N-heterocyclic arenes, double bonds, ketones, cyanides and ester functional groups are well retained after N-methylation of the corresponding functionalized nitroarenes. In addition, benzylic-type as well as aliphatic nitro compounds can also be methylated following this protocol. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

In vitro cytotoxicity and differential cellular sensitivity of derivatives of diamino acids. II. N1-methyl, N1-allyl, N1-(2-chloroethyl) and N1-propargyl nitrosoureas.

PubMed

Dulude, H; Salvador, R; Gallant, G

1995-01-01

The in vitro cytotoxicity and differential cellular sensitivity of a series of new N1-methyl, N1-allyl, N1-2-chloroethyl and N1-propargyl nitrosourea derivatives of diamino acids were determined in the National Cancer Institute's primary antitumor drug screen. The compounds tested showed an in vitro anticancer activity similar to commercialized nitrosoureas such as CCNU, BCNU, MeCCNU, chlorozotocin, streptozotocin and PCNU. The alkylating moiety of the nitrosoureas seems to play a role in the general selectivity of our compounds. The N1-methyl and N1-2-chloroethyl nitrosourea derivatives are more selective for central nervous system cell lines, the N1-allyl nitrosourea derivatives are more selective for lung cancer cell lines and the N1-propargyl nitrosoureas are more selective for leukemia cell lines.

N-(1-Allyl-1H-indazol-5-yl)-4-methyl-benzene-sulfonamide.

PubMed

Chicha, Hakima; Rakib, El Mostapha; Abderrafia, Hafid; Saadi, Mohamed; El Ammari, Lahcen

2013-11-30

The asymmetric unit of the title compound, C17H17N3O2S, contains two independent mol-ecules linked by an N-H⋯O hydrogen bond. The mol-ecules show different conformations. In the first mol-ecule, the fused five- and six-membered ring system is almost perpendicular to the plane through the atoms forming the allyl group, as indicated by the dihedral angle of 85.1 (4)°. The dihedral angle with the methyl-benzene-sulfonamide group is 78.8 (1)°. On the other hand, in the second mol-ecule, the dihedral angles between the indazole plane and the allyl and methyl-benzene-sulfonamide groups are 80.3 (3) and 41.5 (1)°, respectively. In the crystal, mol-ecules are further linked by N-H⋯N and C-H⋯O hydrogen bonds, forming a three-dimensional network.

Rapid in situ detection of street samples of drugs of abuse on textile substrates using microRaman spectroscopy.

PubMed

Ali, Esam M A; Edwards, Howell G M; Scowen, Ian J

2011-10-01

Trace amounts of street samples of cocaine hydrochloride and N-methyl-3,4-methylenedioxy-amphetamine (MDMA) on natural and synthetic textiles were successfully detected in situ using confocal Raman microscopy. The presence of some excipient bands in the spectra of the drugs did not prevent the unambiguous identification of the drugs. Raman spectra of the drugs were readily obtained without significant interference from the fibre substrates. Interfering bands arising from the fibre natural or synthetic polymer structure and/or dye molecules did not overlap with the characteristic Raman bands of the drugs. If needed, interfering bands could be successfully removed by spectral subtraction. Also, Raman spectra could be acquired from drug particles trapped between the fibres of highly fluorescent textile specimens. The total acquisition time of the spectra of the drug particles was 90 s accomplished non-destructively and without detachment from their substrates. Sample preparation was not required and spectra of the drugs could be obtained non-invasively preserving the integrity of the evidential material for further analysis. Copyright © 2010 Elsevier B.V. All rights reserved.

Rapid in situ detection of street samples of drugs of abuse on textile substrates using microRaman spectroscopy

NASA Astrophysics Data System (ADS)

Ali, Esam M. A.; Edwards, Howell G. M.; Scowen, Ian J.

2011-10-01

Trace amounts of street samples of cocaine hydrochloride and N-methyl-3,4-methylenedioxy-amphetamine (MDMA) on natural and synthetic textiles were successfully detected in situ using confocal Raman microscopy. The presence of some excipient bands in the spectra of the drugs did not prevent the unambiguous identification of the drugs. Raman spectra of the drugs were readily obtained without significant interference from the fibre substrates. Interfering bands arising from the fibre natural or synthetic polymer structure and/or dye molecules did not overlap with the characteristic Raman bands of the drugs. If needed, interfering bands could be successfully removed by spectral subtraction. Also, Raman spectra could be acquired from drug particles trapped between the fibres of highly fluorescent textile specimens. The total acquisition time of the spectra of the drug particles was 90 s accomplished non-destructively and without detachment from their substrates. Sample preparation was not required and spectra of the drugs could be obtained non-invasively preserving the integrity of the evidential material for further analysis.

Crystal structures of isomeric 3,5-di-chloro-N-(2,3-di-methyl-phen-yl)benzene-sulfonamide, 3,5-di-chloro-N-(2,6-di-methyl-phen-yl)benzene-sulfonamide and 3,5-di-chloro-N-(3,5-di-methyl-phen-yl)benzene-sulfonamide.

PubMed

Shakuntala, K; Naveen, S; Lokanath, N K; Suchetan, P A

2017-05-01

The crystal structures of three isomeric compounds of formula C 14 H 13 Cl 2 NO 2 S, namely 3,5-di-chloro- N -(2,3-di-methyl-phen-yl)-benzene-sulfonamide (I), 3,5-di-chloro- N -(2,6-di-methyl-phen-yl)benzene-sulfonamide (II) and 3,5-di-chloro- N -(3,5-di-methyl-phen-yl)benzene-sulfonamide (III) are described. The mol-ecules of all the three compounds are U-shaped with the two aromatic rings inclined at 41.3 (6)° in (I), 42.1 (2)° in (II) and 54.4 (3)° in (III). The mol-ecular conformation of (II) is stabilized by intra-molecular C-H⋯O hydrogen bonds and C-H⋯π inter-actions. The crystal structure of (I) features N-H⋯O hydrogen-bonded R 2 2 (8) loops inter-connected via C (7) chains of C-H⋯O inter-actions, forming a three-dimensional architecture. The structure also features π-π inter-actions [ Cg ⋯ Cg = 3.6970 (14) Å]. In (II), N-H⋯O hydrogen-bonded R 2 2 (8) loops are inter-connected via π-π inter-actions [inter-centroid distance = 3.606 (3) Å] to form a one-dimensional architecture running parallel to the a axis. In (III), adjacent C (4) chains of N-H⋯O hydrogen-bonded mol-ecules running parallel to [010] are connected via C-H⋯π inter-actions, forming sheets parallel to the ab plane. Neighbouring sheets are linked via offset π-π inter-actions [inter-centroid distance = 3.8303 (16) Å] to form a three-dimensional architecture.

Stimulation of Methanogenesis by Aldicarb and Several Other N-Methyl Carbamate Pesticides †

PubMed Central

Kiene, Ronald P.; Capone, Douglas G.

1986-01-01

Aldicarb and several other N-methyl carbamate pesticides stimulated methane production in anaerobic salt marsh soils and organic-rich aquifer soils. Stimulation was biological and linearly related to the amount of carbamate added. Of the four carbamates studied, methomyl gave the greatest stimulation followed by carbaryl, aldicarb, and baygon. The percent conversions [(moles of CH4 in excess of control/mole of carbamate added) × 100] for methomyl, carbaryl, aldicarb, and baygon were 88, 57, 40, and 11, respectively. Using aldicarb as a model carbamate, we found that monomethylamine (MA) accumulated in sediments as a result of aldicarb addition. MA arises from the N-methyl carbamoyl portion of the carbamates as a result of presumptive biological hydrolysis. MA levels decreased as CH4 production was stimulated, and 2-bromoethane sulfonic acid (a specific inhibitor of mathanogenesis) partially inhibited the loss of MA. These findings suggest that N-methyl carbamates are readily hydrolyzed to MA in the presence of an active microbial population under anaerobic conditions and that methanogenesis is stimulated as a result of the consumption of MA by methanogenic bacteria. PMID:16347082

Oxygenated N-Acyl Alanine Methyl Esters (NAMEs) from the Marine Bacterium Roseovarius tolerans EL-164.

PubMed

Bruns, Hilke; Herrmann, Jennifer; Müller, Rolf; Wang, Hui; Wagner Döbler, Irene; Schulz, Stefan

2018-01-26

The marine bacterium Roseovarius tolerans EL-164 (Rhodobacteraceae) can produce unique N-acylalanine methyl esters (NAMEs) besides strucutrally related N-acylhomoserine lactones (AHLs), bacterial signaling compounds widespread in the Rhodobacteraceae. The structures of two unprecedented NAMEs carrying a rare terminally oxidized acyl chain are reported here. The compounds (Z)-N-16-hydroxyhexadec-9-enoyl-l-alanine methyl ester (Z9-16-OH-C16:1-NAME, 3) and (Z)-N-15-carboxypentadec-9-enoyl-l-alanine methyl ester (16COOH-C16:1-NAME, 4) were isolated, and the structures were determined by NMR and MS experiments. Both compounds were synthesized to prove assignments and to test their biological activity. Finally, non-natural, structurally related Z9-3-OH-C16:1-NAME (18) was synthesized to investigate the mass spectroscopy of structurally related NAMEs. Compound 3 showed moderate antibacterial activity against microorganisms such as Bacillus, Streptococcus, Micrococcus, or Mucor strains. In contrast to AHLs, quorum-sensing or quorum-quenching activity was not observed.

Rotationally inelastic scattering of methyl radicals with Ar and N{sub 2}

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

Tkáč, Ondřej; Orr-Ewing, Andrew J., E-mail: a.orr-ewing@bristol.ac.uk; Ma, Qianli

2015-01-07

The rotationally inelastic scattering of methyl radical with Ar and N{sub 2} is examined at collision energies of 330 ± 25 cm{sup −1} and 425 ± 50 cm{sup −1}, respectively. Differential cross sections (DCSs) were measured for different final n′ rotational levels (up to n′ = 5) of the methyl radicals, averaged over k′ sub-levels, using a crossed molecular beam machine with velocity map imaging. For Ar as a collision partner, we present a newly constructed ab initio potential energy surface and quantum mechanical scattering calculations of state-resolved DCSs. These computed DCSs agree well with the measurements. The DCSs formore » both Ar and N{sub 2} collision partners are strongly forward peaked for all spectroscopic lines measured. For scattering angles below 60°, the theoretical CD{sub 3}–Ar DCSs show diffraction oscillations that become less pronounced as n′ increases, but these oscillations are not resolved experimentally. Comparisons are drawn with our recently reported DCSs for scattering of methyl radicals with He atoms.« less

Analysis of DNA methylation in Arabidopsis thaliana based on methylation-sensitive AFLP markers.

PubMed

Cervera, M T; Ruiz-García, L; Martínez-Zapater, J M

2002-12-01

AFLP analysis using restriction enzyme isoschizomers that differ in their sensitivity to methylation of their recognition sites has been used to analyse the methylation state of anonymous CCGG sequences in Arabidopsis thaliana. The technique was modified to improve the quality of fingerprints and to visualise larger numbers of scorable fragments. Sequencing of amplified fragments indicated that detection was generally associated with non-methylation of the cytosine to which the isoschizomer is sensitive. Comparison of EcoRI/ HpaII and EcoRI/ MspI patterns in different ecotypes revealed that 35-43% of CCGG sites were differentially digested by the isoschizomers. Interestingly, the pattern of digestion among different plants belonging to the same ecotype is highly conserved, with the rate of intra-ecotype methylation-sensitive polymorphisms being less than 1%. However, pairwise comparisons of methylation patterns between samples belonging to different ecotypes revealed differences in up to 34% of the methylation-sensitive polymorphisms. The lack of correlation between inter-ecotype similarity matrices based on methylation-insensitive or methylation-sensitive polymorphisms suggests that whatever the mechanisms regulating methylation may be, they are not related to nucleotide sequence variation.

Synthesis and characterization of a thermo-sensitive poly( N-methyl acryloylglycine methyl ester) used as a drug release carrier

NASA Astrophysics Data System (ADS)

Deng, Kui-Lin; Zhong, Hai-Bin; Jiao, Yi-Suo; Fan, Ting; Qiao, Xiao; Zhang, Peng-Fei; Ren, Xiao-Bo

2010-06-01

In this article, poly( N-methyl acryloylglycine methyl ester) (PNMAME) was prepared as a novel thermosensitive material with a lower critical solution temperature (LCST) at around 49.5°C. The chemical structures of the monomer NMAME and PNMAME were characterized by 1H NMR and IR measurements. The LCST was investigated systematically as a function of PNMAME concentration, inorganic salt solution and pH value. The results indicated that LCST of PNMAME was obviously dependent on PNMAME concentration and pH. The LCST was increased with a decrease in pH value and PNMAME concentration. To obtain a thermo-sensitive hydrogel with the phase transition temperature close to human body temperature, the copolymerization was conducted between NMAME and N-acryloylglycine ethyl ester (NAGEE). The release behavior of caffeine was evaluated at different temperatures and contents of cross-linkers ( N, N-methylenebis(acrylamide) (NMBA)). The increase of cross-linker content led to a decrease in the release rate of caffeine due to higher crossing density in the hydrogel network. In addition, a faster release of caffeine from the hydrogel with 3% NMBA at 37°C was found in contrast to that at 18°C.

Crystal structure of {2,6-bis-[(di-methyl-amino)-meth-yl]phenyl-κ3N,C1,N'}(bromido/chlorido)-mercury(II).

PubMed

Gupta, Anand; Singh, Harkesh B; Butcher, Ray J

2017-11-01

In the mol-ecular structure of the title compound, {2,6-bis-[(di-methyl-amino)-meth-yl]phenyl-κ 3 N , C 1 , N '}[bromido/chlorido-(0.30/0.70)]mercury(II)-{2,6-bis-[(di-methyl-amino)-meth-yl]phenyl-κ 3 N , C 1 , N '}[bromido/chlorido-(0.24/0.76)]mer-cury(II) (1/1), [HgBr 0.30 Cl 0.70 (C 12 H 19 N 2 )]·[HgBr 0.24 Cl 0.76 (C 12 H 19 N 2 )], there are two mol-ecules in the asymmetric unit of formula L Hg X { L = 2,6-bis-[(di-methyl-amino)-meth-yl]phenyl and X = Cl/Br}. In each mol-ecule, the halide site is mixed Cl/Br, with occupancies of 0.699 (7):0.301 (7) and 0.763 (7):0.237 (7), respectively. The two mol-ecules are linked into dimers by a combination of Hg⋯Hg [Hg⋯Hg = 3.6153 (3) Å] and C-H⋯Cl and C-H⋯π inter-actions.

[Mammary gland tumor induction in rats by N-nitroso-N-methylurea and N-methyl-N1-nitro-N-nitrosoguanidine].

PubMed

Eliseev, V V; Vlasov, N N

1980-01-01

Cancer of the mammary gland was induced in female non-inbred rats under the local effect of N-nitroso-N-methylurea (NMU) and N-methyl-N-nitro-N-nitrosoguanidine (MNNG). During 10 weeks 2.5 mg of the substance in 0.2 ml of saline was injected in the region of the third mammary gland once a week. Under NMU exposure a primary tumor arose 3 months following the initiation of the experiment, the average latent period being 5.8 months, the incidence rate--76.7%. All tumors of this series were adenocarcinomas, in 5 cases there were noted sites of fibroadenomatosis with malignification along the tumor node margins. MNNG produced a primary tumor at the 7th month of the experiment, an average latent period--8.3 months, the incidence rate--56.7%. Tumors were mostly adenocarcinomas.

[Analysis of genomic DNA methylation level in radish under cadmium stress by methylation-sensitive amplified polymorphism technique].

PubMed

Yang, Jin-Lan; Liu, Li-Wang; Gong, Yi-Qin; Huang, Dan-Qiong; Wang, Feng; He, Ling-Li

2007-06-01

The level of cytosine methylation induced by cadmium in radish (Raphanus sativus L.) genome was analysed using the technique of methylation-sensitive amplified polymorphism (MSAP). The MSAP ratios in radish seedling exposed to cadmium chloride at the concentration of 50, 250 and 500 mg/L were 37%, 43% and 51%, respectively, and the control was 34%; the full methylation levels (C(m)CGG in double strands) were at 23%, 25% and 27%, respectively, while the control was 22%. The level of increase in MSAP and full methylation indicated that de novo methylation occurred in some 5'-CCGG sites under Cd stress. There was significant positive correlation between increase of total DNA methylation level and CdCl(2) concentration. Four types of MSAP patterns: de novo methylation, de-methylation, atypical pattern and no changes of methylation pattern were identified among CdCl(2) treatments and the control. DNA methylation alteration in plants treated with CdCl(2) was mainly through de novo methylation.

N-Methyl-D-Aspartate Receptor Activation May Contribute to Glufosinate Neurotoxicity

EPA Science Inventory

N-Methyl-D-aspartate Receptor Activation May Contribute to Glufosinate Neurotoxicity Glufosinate (GLF) at high levels in mammals causes convulsions through a mechanism that is not completely understood. The structural similarity of GLF to glutamate (GLU) implicates the glutamate...

Nonparaneoplastic anti-N-methyl-D-aspartate receptor encephalitis: a case series of four children.

PubMed

Raha, Sarbani; Gadgil, Pradnya; Sankhla, Charulata; Udani, Vrajesh

2012-04-01

A rare, severe form of immune-mediated encephalitis recently has been described, associated with antibodies against N-methyl-D-aspartate receptors. It is reported mostly in women with ovarian tumors. Nonparaneoplastic presentations are less common. We describe four children with a neuropsychiatric and extrapyramidal syndrome associated with the presence of anti-N-methyl-D-aspartate receptor antibodies in cerebrospinal fluid and serum, without evidence of neoplasia. Three children recovered completely after immunomodulatory therapy, i.e., intravenous immunoglobulin and/or steroids, methylprednisolone, and/or adrenocorticotrophic hormone. Copyright © 2012 Elsevier Inc. All rights reserved.

The cocrystal rac-1-[(N,4-dimethylbenzenesulfonamido)methyl]-2-(diphenylphosphoryl)ferrocene-rac-1-[(N,4-dimethylbenzenesulfonamido)methyl]-2-(diphenylphosphanyl)ferrocene (0.45/0.55).

PubMed

Wei, Muh Mei; Audin, Catherine; Manoury, Eric; Deydier, Eric; Daran, Jean Claude

2014-03-01

As part of our interest in the synthesis and catalytic applications of chiral (diphenylphosphanyl)ferrocene ligands, we designed a number of P,N-containing ligands for use in asymmetric transfer hydrogenation (ATH). During the synthetic procedure to obtain rac-1-[(N,4-dimethylbenzenesulfonamido)methyl]-2-(diphenylphosphanyl)ferrocene, the title compound, [Fe(C5H5)(C26H25NO2PS)]0.55 · [Fe(C5H5)(C26H25NO3PS)]0.45, was obtained as a by-product. It is composed of a ferrocene group disubstituted by a partially oxidized diphenylphosphanyl group, as confirmed by (31)P NMR analysis, and an (N,4-dimethylbenzenesulfonamido)methyl substituent. Owing to the partially oxidized diphenylphosphanyl group, it is best to view the crystal as being composed of a mixture of non-oxidized and oxidized phosphane, so it can be regarded as a cocrystal. It is also a racemate. To the best of our knowledge, the P=O distance [1.344 (4) Å] is the shortest observed for related (diphenylphosphoryl)ferrocene compounds. The packing is stabilized by weak C-H...O interactions, forming R2(2)(10) hydrogen-bonding motifs, which build up a chain along the c axis.

Design synthesis and structure-activity relationship of 5-substituted (tetrahydronaphthalen-2yl)methyl with N-phenyl-N-(piperidin-2-yl)propionamide derivatives as opioid ligands.

PubMed

Deekonda, Srinivas; Rankin, David; Davis, Peg; Lai, Josephine; Vanderah, Todd W; Porecca, Frank; Hruby, Victor J

2016-01-15

Here, we report the design, synthesis and structure activity relationship of novel small molecule opioid ligands based on 5-amino substituted (tetrahydronaphthalen-2-yl)methyl moiety with N-phenyl-N-(piperidin-2-yl)propionamide derivatives. We synthesized various molecules including amino, amide and hydroxy substitution on the 5th position of the (tetrahydronaphthalen-2-yl)methyl moiety. In our further designs we replaced the (tetrahydronaphthalen-2-yl)methyl moiety with benzyl and phenethyl moiety. These N-phenyl-N-(piperidin-2-yl)propionamide analogues showed moderate to good binding affinities (850-4 nM) and were selective towards the μ opioid receptor over the δ opioid receptors. From the structure activity relationship studies, we found that a hydroxyl substitution at the 5th position of (tetrahydronapthalen-2yl)methyl group, ligands 19 and 20, showed excellent binding affinities 4 and 5 nM, respectively, and 1000 fold selectivity towards the μ opioid relative to the delta opioid receptor. The ligand 19 showed potent agonist activities 75±21 nM, and 190±42 nM in the GPI and MVD assays. Surprisingly the fluoro analogue 20 showed good agonist activities in MVD assays 170±42 nM, in contrast to its binding affinity results. Copyright © 2015 Elsevier Ltd. All rights reserved.

N-hexane inhalation during pregnancy alters DNA promoter methylation in the ovarian granulosa cells of rat offspring.

PubMed

Li, Hong; Liu, Jin; Sun, Yan; Wang, Wenxiang; Weng, Shaozheng; Xiao, Shihua; Huang, Huiling; Zhang, Wenchang

2014-08-01

The N-hexane-induced impact on the reproductive system of the offspring of animals exposed to n-hexane has caused great concern. Pregnant Wistar rats inhaled 500, 2 500 or 12 500 ppm n-hexane during gestational days 1-20. Clinical characteristics and developmental indices were observed. Ovarian granulosa cells were extracted from F1 rats, the number of follicles was determined in ovarian slices and promoter methylation was assessed using MeDIP-Chip. Several methods were used to analyze the scanned genes, including the Gene Ontology Consortium tools, the DAVID Functional Annotation Clustering Tool, hierarchical clustering and KEGG pathway analysis. The results indicated that the live pups/litter ratio was significantly lowest in the 12 500 ppm group. A significant decrease in secondary follicles and an increase in atresic follicles were observed in the 12 500 ppm group. The number of shared demethylated genes was higher than that of the methylated genes, and the differentially methylated genes were enriched in cell death and apoptosis, cell growth and hormone regulation. The methylation profiles of the offspring from the 500 ppm and control groups were different from those of the 2500 and 12 500 ppm groups. Furthermore, the methylation status of genes in the PI3K-Akt and NF-kappa B signaling pathways was changed after n-hexane exposure. The Cyp11a1, Cyp17a1, Hsd3b1, Cyp1a1 and Srd5a1 promoters were hypermethylated in the n-hexane-exposed groups. These results indicate that the developmental toxicity of n-hexane in F1 ovaries is accompanied by the altered methylation of promoters of genes associated with apoptotic processes and steroid hormone biosynthesis. Copyright © 2013 John Wiley & Sons, Ltd.

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.

Resistance of Salmonella typhimurium TA 1535 to O6-guanine methylation and mutagenesis induced by low doses of N-methyl-N'-nitro-N-nitrosoguanidine: an apparent constitutive repair activity.

PubMed

Guttenplan, J B; Milstein, S

1982-01-01

Salmonella tester strains which are reverted by base-pair substitution mutagens are relatively insensitive to the mutagenic effects of N-methyl-N-nitroso compounds. One reason for this insensitivity is the ability of these strains to withstand low doses of these compounds before they become sensitive to their mutagenic effects. In this report it is shown that mutagenesis induced by treatment of Salmonella typhimurium TA 1535 with N-methyl-N'-nitro-N-nitroso-guanidine (MNNG) in buffer is biphasic with a low sensitivity range at low doses where little mutagenesis occurs, followed by a high sensitivity range whose onset begins after an apparent threshold dose has been exceeded. levels of O6-methylguanine (O6-MeG) in the DNA extracted from the bacteria follow a similar dose-response curve suggesting a dependency of mutagenesis on O6-MeG. In contrast, levels of 7-methylguanine (7-MeG) in the DNA increase linearly with dose. O6-MeG was undetectable at the lowest dose of MNNG whereas 7-MeG was readily detectable. Although such resistance to O6-alkylation has been demonstrated in MNNG- pretreated (adapted) E. coli, it has not been reported in unpretreated cells. Then isolated DNA was treated with MNNG a linear dose-response in the generation of O6-MeG was observed. The lack of O6-MeG in DNA isolated from MNNG treated cells after low doses is attributed to a saturable, constitutive repair activity in the bacteria. An attempt to observe the removal of O6-MeG from the bacteria after exposure to a short challenge dose of N-nitroso-N-methylurea (NMU) followed by a subsequent incubation in buffer was unsuccessful, probably because all the repair occurred within the time necessary to treat and lyse the cells.

Computational Study of Environmental Effects on Torsional Free Energy Surface of N-Acetyl-N'-methyl-L-alanylamide Dipeptide

ERIC Educational Resources Information Center

Carlotto, Silvia; Zerbetto, Mirco

2014-01-01

We propose an articulated computational experiment in which both quantum mechanics (QM) and molecular mechanics (MM) methods are employed to investigate environment effects on the free energy surface for the backbone dihedral angles rotation of the small dipeptide N-Acetyl-N'-methyl-L-alanylamide. This computation exercise is appropriate for an…

Crystal structure of N-[3-(di­methyl­aza­nium­yl)prop­yl]-N′,N′,N′′,N′′-tetra­methyl-N-(N,N,N′,N′-tetra­methyl­form­am­id­in­ium­yl)­guanidinium dibromide hydroxide monohydrate

PubMed Central

Tiritiris, Ioannis; Kantlehner, Willi

2015-01-01

The asymmetric unit of the title hydrated salt, C15H37N6 3+·2Br−·OH−·H2O, contains one cation, three partial-occupancy bromide ions, one hydroxide ion and one water mol­ecule. Refinement of the site-occupancy factors of the three disordered bromide ions converges with occupancies 0.701 (2), 0.831 (2) and 0.456 (2) summing to approximately two bromide ions per formula unit. The structure was refined as a two-component inversion twin with volume fractions 0.109 (8):0.891 (8) for the two domains. The central C3N unit of the bis­amidinium ion is linked to the aliphatic propyl chain by a C—N single bond. The other two bonds in this unit have double-bond character as have the four C—N bonds to the outer NMe2 groups. In contrast, the three C—N bonds to the central N atom of the (di­methyl­aza­nium­yl)propyl group have single-bond character. Delocalization of the two positive charges occurs in the N/C/N and C/N/C planes, while the third positive charge is localized on the di­methyl­ammonium group. The crystal structure is stabilized by O—H⋯O, N—H⋯Br, O—H⋯Br and C—H⋯Br hydrogen bonds, forming a three-dimensional network. PMID:26870507

Pharmacokinetics of S-3-(4-acetylamino-phenoxy)-2-hydroxy-2-methyl-N-(4-nitro-3-trifluoromethyl-phenyl)-propionamide in rats, a non-steroidal selective androgen receptor modulator

PubMed Central

KEARBEY, J. D.; WU, D.; GAO, W.; MILLER, D. D.; DALTON, J. T.

2007-01-01

1. S-3-(4-acetylamino-phenoxy)-2-hydroxy-2-methyl-N-(4-nitro-3-trifluoromethyl-phenyl)-propionamide (also known as S-4) is a non-steroidal selective androgen receptor modulator demonstrating tissue-selective androgenic and anabolic effects. The purpose of the present study was to examine the systemic pharmacokinetics, elimination and oral bioavailability of S-4 in rats. 2. Thirty-five male Sprague–Dawley rats weighing approximately 250 g were randomly assigned to one of seven treatment groups. Intravenous doses of 0.5, 1, 10, and 30 mg kg−1 were given via a jugular catheter. Oral doses of 1, 10 and 30 mg kg−1 were administered via gavage. Plasma concentrations were determined using a validated high-performance liquid chromatography or by a high-performance liquid chromatography/mass spectrometry method. 3. Clearances ranged between 1.0 and 2.1 ml min−1 kg−1 and varied with dose. The volume of distribution was approximately 0.448 l kg−1 in all treatment groups. Oral bioavailability was also dose dependent, with the lower doses showing complete oral bioavailability. The half-life of S-4 over the dose range tested was between 2.6 and 5.3 h. 4. It was demonstrated that S-4 is rapidly absorbed, slowly cleared, and has a moderate volume of distribution in rats. The pharmacokinetics and oral bioavailability of S-4 indicate that it is an excellent candidate for clinical development. PMID:15204699

Dibromidobis(N,N,N′,N′-tetra­methyl­thio­urea-κS)cadmium(II)

PubMed Central

Nawaz, Sidra; Sadaf, Sana; Fettouhi, Mohammed; Fazal, Atif; Ahmad, Saeed

2010-01-01

In the title compound, [CdBr2(C5H12N2S)2], the CdII atom lies on a twofold rotation axis. It exhibits a distorted tetra­hedral coordination environment defined by two S atoms of two tetra­methyl­thio­urea (tmtu) ligands and two bromide ions. The crystal structure is consolidated by C—H⋯N and C—H⋯S hydrogen bonds. PMID:21588180

Crystal structure of [(2R,3R,4S)-3,4-bis(acet-yloxy)-5-iodo-3,4-di-hydro-2H-pyran-2-yl]methyl acetate.

PubMed

Zukerman-Schpector, Julio; Caracelli, Ignez; Stefani, Hélio A; Shamim, Anwar; Tiekink, Edward R T

2015-01-01

In the title compound, C12H15IO7, the 3,4-di-hydro-2H-pyran ring is in a distorted half-boat conformation with the atom bearing the acet-yloxy group adjacent to the C atom bearing the methyl-acetate group lying 0.633 (6) Å above the plane of the remaining ring atoms (r.m.s. deviation = 0.0907 Å). In the crystal, mol-ecules are linked into a supra-molecular chain along the a axis through two C-H⋯O inter-actions to the same acceptor carbonyl O atom; these chains pack with no specific inter-molecular inter-actions between them.

40 CFR 180.296 - Dimethyl phosphate of 3-hydroxy-N-methyl-cis-crotonamide; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-methyl-cis-crotonamide; tolerances for residues. 180.296 Section 180.296 Protection of Environment... RESIDUES IN FOOD Specific Tolerances § 180.296 Dimethyl phosphate of 3-hydroxy-N-methyl-cis-crotonamide; tolerances for residues. (a) General. Tolerances are established for residues of the insecticide Dimethyl...

Residual Deep Convolutional Neural Network Predicts MGMT Methylation Status.

PubMed

Korfiatis, Panagiotis; Kline, Timothy L; Lachance, Daniel H; Parney, Ian F; Buckner, Jan C; Erickson, Bradley J

2017-10-01

Predicting methylation of the O6-methylguanine methyltransferase (MGMT) gene status utilizing MRI imaging is of high importance since it is a predictor of response and prognosis in brain tumors. In this study, we compare three different residual deep neural network (ResNet) architectures to evaluate their ability in predicting MGMT methylation status without the need for a distinct tumor segmentation step. We found that the ResNet50 (50 layers) architecture was the best performing model, achieving an accuracy of 94.90% (+/- 3.92%) for the test set (classification of a slice as no tumor, methylated MGMT, or non-methylated). ResNet34 (34 layers) achieved 80.72% (+/- 13.61%) while ResNet18 (18 layers) accuracy was 76.75% (+/- 20.67%). ResNet50 performance was statistically significantly better than both ResNet18 and ResNet34 architectures (p < 0.001). We report a method that alleviates the need of extensive preprocessing and acts as a proof of concept that deep neural architectures can be used to predict molecular biomarkers from routine medical images.

40 CFR 721.2275 - N,N,N′,N′-Tetrakis(oxi-ranyl- methyl)-1,3-cyclohexane di-meth-anamine.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false N,N,Nâ²,Nâ²-Tetrakis(oxi-ranyl- methyl)-1,3-cyclohexane di-meth-anamine. 721.2275 Section 721.2275 Protection of Environment ENVIRONMENTAL...-cyclohexane di-meth-anamine. (a) Chemical substances and significant new uses subject to reporting. (1) The...

40 CFR 721.2275 - N,N,N′,N′-Tetrakis(oxi-ranyl- methyl)-1,3-cyclohexane di-meth-anamine.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false N,N,Nâ²,Nâ²-Tetrakis(oxi-ranyl- methyl)-1,3-cyclohexane di-meth-anamine. 721.2275 Section 721.2275 Protection of Environment ENVIRONMENTAL...-cyclohexane di-meth-anamine. (a) Chemical substances and significant new uses subject to reporting. (1) The...

40 CFR 721.2275 - N,N,N′,N′-Tetrakis(oxi-ranyl- methyl)-1,3-cyclohexane di-meth-anamine.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false N,N,Nâ²,Nâ²-Tetrakis(oxi-ranyl- methyl)-1,3-cyclohexane di-meth-anamine. 721.2275 Section 721.2275 Protection of Environment ENVIRONMENTAL...-cyclohexane di-meth-anamine. (a) Chemical substances and significant new uses subject to reporting. (1) The...

Enzymatic hydrolysis of cellulose pretreated with ionic liquids and N-methyl Morpholine N-Oxide

NASA Astrophysics Data System (ADS)

Yau Li, Elizabeth

The effect of N-methyl Morpholine N-Oxide (NMMO), 1-ethyl-3-methyl-imidazolium acetate ([Emim]Ac) and 1-ethyl-3-methyl-imidazolium diethyl phosphate ([Emim]DEP) on pretreatment and enzymatic hydrolysis of dissolving pulp was studied. X-ray diffraction measurements of regenerated cellulose from these solvents showed that solvent pretreatment reduces the crystallinity of cellulose. However, crystallinity might not be a major factor affecting the in-situ enzymatic hydrolysis of cellulose in these solvents. Although regenerated cellulose from [Emim]DEP showed the lowest crystallinity index (˜15%), in-situ enzymatic hydrolysis of cellulose dissolved in NMMO showed the highest cellulose conversion (68% compared to 65% for [Emim]Ac and 37% for [Emim]DEP at enzyme loading of 122 FPU/g). Moreover, results showed that enzymes could tolerate up to NMMO concentration of 100 g/L and still yield full conversion of cellulose. Since it is not necessary to remove all the NMMO, less amount of water will be required for the washing step and thus the process will be more economical. The HCH-1 model was used in an attempt to model the enzymatic hydrolysis of cellulose in NMMO. With the incorporation of NMMO inhibition and a factor to account for unreacted cellulose, the model was able to correlate the experimental data of the enzymatic hydrolysis of cellulose (6.68 g/L) at various NMMO concentrations (0, 50, 100, 150 and 250 g/L). However, the experimental results also suggest that NMMO might be deactivating the enzymes rather than inhibiting them. More studies need to be done at varying cellulose, NMMO and enzyme concentrations to find the exact nature of this deactivation of NMMO.

Density and viscosity of aqueous blends of N-methyldiethanolamine and 2-amino-2-methyl-1-propanol

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

Welsh, L.M.; Davis, R.A.

Aqueous solutions of alkanolamines such as N-methyldiethanolamine (MDEA) and 2-amino-2-methyl-1-propanol (AMP) have application in acid gas treatment for the removal of acid gases such as carbon dioxide and hydrogen sulfide. The density and kinematic viscosity of aqueous blends of N-methyldiethanolamine and 2-amino-2-methyl-1-propanol were determined from experiments within the temperature range 10--60 C. The composition of the alkanolamines in water ranged from 5% to 50% by mass.

Tyramine Pathways in Citrus Plant Defense: Glycoconjugates of Tyramine and Its N-Methylated Derivatives.

PubMed

Servillo, Luigi; Castaldo, Domenico; Giovane, Alfonso; Casale, Rosario; D'Onofrio, Nunzia; Cautela, Domenico; Balestrieri, Maria Luisa

2017-02-01

Glucosylated forms of tyramine and some of its N-methylated derivatives are here reported for the first time to occur in Citrus genus plants. The compounds tyramine-O-β-d-glucoside, N-methyltyramine-O-β-d-glucoside, and N,N-dimethyltyramine-O-β-d-glucoside were detected in juice and leaves of sweet orange, bitter orange, bergamot, citron, lemon, mandarin, and pomelo. The compounds were identified by mass spectrometric analysis, enzymatic synthesis, and comparison with extracts of Stapelia hirsuta L., a plant belonging to the Apocynaceae family in which N,N-dimethyltyramine-O-β-d-glucoside was identified by others. Interestingly, in Stapelia hirsuta we discovered also tyramine-O-β-d-glucoside, N-methyltyramine-O-β-d-glucoside, and the tyramine metabolite, N,N,N-trimethyltyramine-O-β-glucoside. However, the latter tyramine metabolite, never described before, was not detected in any of the Citrus plants included in this study. The presence of N-methylated tyramine derivatives and their glucosylated forms in Citrus plants, together with octopamine and synephrine, also deriving from tyramine, supports the hypothesis of specific biosynthetic pathways of adrenergic compounds aimed to defend against biotic stress.

A DOSE-RESPONSE STUDY OF THE TOXICITY OF A MIXTURE OF 7N-METHYL CARBAMATE PESTICIDES IN ADULT, MALE RATS.

EPA Science Inventory

There is scarce knowledge regarding the toxicity of pesticide mixtures, especially mixtures of the anticholinesterase N-methyl carbamates. A mixture study was conducted using 7 N-methyl carbamates (carbaryl, carbofuran, formetanate HCl, methiocarb, methomyl, oxamyl, and propoxur...

N,N,N′,N′-Tetra­methyl­guanidinium tetra­phenyl­borate

PubMed Central

Tiritiris, Ioannis

2012-01-01

In the title salt, C5H14N3 +·C24H20B−, the C—N bond lengths in the central CN3 unit are 1.3322 (11), 1.3385 (12) and 1.3422 (12) Å, indicating partial double-bond character. The central C atom is bonded to the three N atoms in a nearly ideal trigonal-planar geometry [N—C—N angles = 119.51 (8), 119.81 (9) and 120.69 (8)°] and the positive charge is delocalized in the CN3 plane. The bond lengths between the N atoms and the terminal methyl groups all have values close to a typical single bond [1.4597 (12)–1.4695 (13) Å]. The crystal packing is caused by electrostatic inter­actions between cations and anions. PMID:23476307

Effect of pressure on bilayer phase behavior of N-methylated di-O-hexadecylphosphatidylethanolamines: relevance of head-group modification on the bilayer interdigitation.

PubMed

Goto, Masaki; Aoki, Yuya; Tamai, Nobutake; Matsuki, Hitoshi

2017-12-01

The phase transitions of N-methylated di-O-hexadecylphosphatidylethanolamines (DHPE, DH-N-methyl-PE (DHMePE) and DH-N,N-dimethyl-PE (DHMe 2 PE)) were observed by differential scanning calorimetry (DSC) and fluorometry under atmospheric pressure and by light-transmittance measurements under high pressure. The DSC thermograms showed that the N-methylated DHPE bilayers underwent the phase transition from the gel phase to the liquid crystalline (L α ) phase under atmospheric pressure. The gel phase was identified by fluorometry as the lamellar gel (L β ) phase, and not interdigitated gel (L β I) phase. The gel/L α transition temperature increased with pressure while decreased stepwise with increasing polar head-group size. This stepwise depression of the transition temperature may be caused by the inverse-proportional hydrogen-bonding capabilities of the head-group to the head-group size. The thermodynamic quantities of the gel/L α transition were comparable for the N-methylated DHPE bilayers. The pressure-induced L β I phase was not found in these bilayers although the bilayer of di-O-hexadecylphosphatidylcholine (DHPC), which is a kind of N-methylated DHPEs, forms the L β I phase only by hydration under atmospheric pressure. Taking into account that the bilayers of diacyl-homologs of N-methylated DHPEs, N-methylated dipalmitoyl-PEs except for dipalmitoylphosphatidylcholine (DPPC), do not form the L β I phase in the whole pressure range investigated but the DPPC bilayer forms the L β I phase under high pressure, we can say that the interdigitation requires weaker interaction between large-sized head groups like the bulky choline group. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis, structural, optical and thermal properties of N-methyl-N-aryl benzamide organic single crystals grown by a slow evaporation technique

NASA Astrophysics Data System (ADS)

Prabukanthan, P.; Lakshmi, R.; Harichandran, G.; Kumar, C. Sudarsana

2018-03-01

The organic materials, N-methyl-N-aryl benzamides were synthesized from benzoylation of N-methyl-4-nitrobenzenamine (MNBA) using suitably substituted benzoyl chlorides. The products were purified by recrystallization and their single crystal were grown by a slow evaporation technique. The crystals were characterized by FTIR, UV-Vis-NIR, 1H &13C NMR, and single & powder X-ray diffraction. Thermal stability of the crystals was studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Dielectric and NLO properties of MNPB, FMNPB and MMNPB crystals were studied. The second harmonic generation (SHG) has been confirmed by the Kurtz powder test for all these crystals and the SHG efficiency of MMNPB crystal was found to be 2.25 times higher than that of KDP crystal.

Aberrant TET1 Methylation Closely Associated with CpG Island Methylator Phenotype in Colorectal Cancer.

PubMed

Ichimura, Norihisa; Shinjo, Keiko; An, Byonggu; Shimizu, Yasuhiro; Yamao, Kenji; Ohka, Fumiharu; Katsushima, Keisuke; Hatanaka, Akira; Tojo, Masayuki; Yamamoto, Eiichiro; Suzuki, Hiromu; Ueda, Minoru; Kondo, Yutaka

2015-08-01

Inactivation of methylcytosine dioxygenase, ten-eleven translocation (TET) is known to be associated with aberrant DNA methylation in cancers. Tumors with a CpG island methylator phenotype (CIMP), a distinct subgroup with extensive DNA methylation, show characteristic features in the case of colorectal cancer. The relationship between TET inactivation and CIMP in colorectal cancers is not well understood. The expression level of TET family genes was compared between CIMP-positive (CIMP-P) and CIMP-negative (CIMP-N) colorectal cancers. Furthermore, DNA methylation profiling, including assessment of the TET1 gene, was assessed in colorectal cancers, as well as colon polyps. The TET1 was silenced by DNA methylation in a subset of colorectal cancers as well as cell lines, expression of which was reactivated by demethylating agent. TET1 methylation was more frequent in CIMP-P (23/55, 42%) than CIMP-N (2/113, 2%, P < 0.0001) colorectal cancers. This trend was also observed in colon polyps (CIMP-P, 16/40, 40%; CIMP-N, 2/24, 8%; P = 0.002), suggesting that TET1 methylation is an early event in CIMP tumorigenesis. TET1 methylation was significantly associated with BRAF mutation but not with hMLH1 methylation in the CIMP-P colorectal cancers. Colorectal cancers with TET1 methylation have a significantly greater number of DNA methylated genes and less pathological metastasis compared to those without TET1 methylation (P = 0.007 and 0.045, respectively). Our data suggest that TET1 methylation may contribute to the establishment of a unique pathway in respect to CIMP-mediated tumorigenesis, which may be incidental to hMLH1 methylation. In addition, our findings provide evidence that TET1 methylation may be a good biomarker for the prediction of metastasis in colorectal cancer. ©2015 American Association for Cancer Research.

Crystal structure and electrochemical properties of [Ni(bztmpen)(CH3CN)](BF4)2 {bztmpen is N-benzyl-N,N',N'-tris-[(6-methyl-pyridin-2-yl)meth-yl]ethane-1,2-di-amine}.

PubMed

Chen, Lin; Ren, Gan; Guo, Yakun; Sang, Ge

2017-06-01

The mononuclear nickel title complex (acetonitrile-κ N ){ N -benzyl- N , N ', N '-tris-[(6-methyl-pyridin-2-yl)meth-yl]ethane-1,2-di-amine}-nickel(II) bis-(tetra-fluor-ido-borate), [Ni(C 30 H 35 N 5 )(CH 3 CN)](BF 4 ) 2 , was prepared from the reaction of Ni(BF 4 ) 2 ·6H 2 O with N -benzyl- N , N ', N '-tris-[(6-methyl-pyridin-2-yl)meth-yl]ethane-1,2-di-amine ( bztmpen ) in aceto-nitrile at room temperature. With an open site occupied by the aceto-nitrile mol-ecule, the nickel(II) atom is chelated by five N-atom sites from the ligand and one N atom from the ligand, showing an overall octa-hedral coordination environment. Compared with analogues where the 6-methyl substituent is absent, the bond length around the Ni 2+ cation are evidently longer. Upon reductive dissociation of the acetro-nitrile mol-ecule, the title complex has an open site for a catalytic reaction. The title complex has two redox couples at -1.50 and -1.80 V ( versus F c +/0 ) based on nickel. The F atoms of the two BF 4 - counter-anions are split into two groups and the occupancy ratios refined to 0.611 (18):0.389 (18) and 0.71 (2):0.29 (2).

mRNA N6-methyladenosine methylation of postnatal liver development in pig.

PubMed

He, Shen; Wang, Hong; Liu, Rui; He, Mengnan; Che, Tiandong; Jin, Long; Deng, Lamei; Tian, Shilin; Li, Yan; Lu, Hongfeng; Li, Xuewei; Jiang, Zhi; Li, Diyan; Li, Mingzhou

2017-01-01

N6-methyladenosine (m6A) is a ubiquitous reversible epigenetic RNA modification that plays an important role in the regulation of post-transcriptional protein coding gene expression. Liver is a vital organ and plays a major role in metabolism with numerous functions. Information concerning the dynamic patterns of mRNA m6A methylation during postnatal development of liver has been long overdue and elucidation of this information will benefit for further deciphering a multitude of functional outcomes of mRNA m6A methylation. Here, we profile transcriptome-wide m6A in porcine liver at three developmental stages: newborn (0 day), suckling (21 days) and adult (2 years). About 33% of transcribed genes were modified by m6A, with 1.33 to 1.42 m6A peaks per modified gene. m6A was distributed predominantly around stop codons. The consensus motif sequence RRm6ACH was observed in 78.90% of m6A peaks. A negative correlation (average Pearson's r = -0.45, P < 10-16) was found between levels of m6A methylation and gene expression. Functional enrichment analysis of genes consistently modified by m6A methylation at all three stages showed genes relevant to important functions, including regulation of growth and development, regulation of metabolic processes and protein catabolic processes. Genes with higher m6A methylation and lower expression levels at any particular stage were associated with the biological processes required for or unique to that stage. We suggest that differential m6A methylation may be important for the regulation of nutrient metabolism in porcine liver.

Sprague-Dawley rats display metabolism-mediated sex differences in the acute toxicity of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy)

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

Fonsart, Julien; Menet, Marie-Claude; Decleves, Xavier

The use of the amphetamine derivative 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) has been associated with unexplained deaths. Male humans and rodents are more sensitive to acute toxicity than are females, including a potentially lethal hyperthermia. MDMA is highly metabolized to five main metabolites, by the enzymes CYP1A2 and CYP2D. The major metabolite in rats, 3,4-methylenedioxyamphetamine (MDA), also causes hyperthermia. We postulated that the reported sex difference in rats is due to a sexual dimorphism(s). We therefore determined (1) the LD50 of MDMA and MDA, (2) their hyperthermic effects, (3) the activities of liver CYP1A2 and CYP2D, (4) the liver microsomal metabolism ofmore » MDMA and MDA, (5) and the plasma concentrations of MDMA and its metabolites 3 h after giving male and female Sprague-Dawley (SD) rats MDMA (5 mg.kg{sup -1} sc). The LD50 of MDMA was 2.4-times lower in males than in females. MDMA induced greater hyperthermia (0.9 deg. C) in males. The plasma MDA concentration was 1.3-fold higher in males, as were CYP1A2 activity (twice) and N-demethylation to MDA (3.3-fold), but the plasma MDMA concentration (1.4-fold) and CYP2D activity (1.3-fold) were higher in females. These results suggest that male SD rats are more sensitive to MDMA acute toxicity than are females, probably because their CYP1A2 is more active, leading to higher N-demethylation and plasma MDA concentration. This metabolic pathway could be responsible for the lethality of MDMA, as the LD50 of MDA is the same in both sexes. These data strongly suggest that the toxicity of amphetamine-related drugs largely depends on metabolic differences.« less

In-situ detection of drugs-of-abuse on clothing using confocal Raman microscopy.

PubMed

Ali, Esam M A; Edwards, Howell G M; Hargreaves, Michael D; Scowen, Ian J

2008-05-12

This study describes the application of confocal Raman microscopy to the detection and identification of drugs-of-abuse in situ on undyed natural synthetic fibres, and coloured textile specimens. Raman spectra were obtained from drug particles trapped between the fibres of the specimens. Pure samples of cocaine hydrochloride and N-methyl-3,4-methylenedioxy-amphetamine HCl (MDMA-HCl) were used in this study. Raman spectra were collected from drug particles of an average size in the range 5-15 microm. Despite the presence of spectral bands arising from the natural and synthetic polymer and dyed textiles, the drugs could be identified by their characteristic Raman bands. If necessary, interfering bands could be successfully removed by spectral subtraction. Furthermore, Raman spectra were recorded from drug particles trapped between the fibres of highly fluorescent specimens. Interference from the fibres, including background fluorescence, was overcome by careful focusing of the confocal beam and the resulting spectra allow ready differentiation from interference from the fibres substrate bands. Spectra of several drugs-of-abuse on dyed and undyed clothing substrates were readily obtained within 3 min with little or no sample preparation and with no alteration of the evidential material.

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

Structure of human IFIT1 with capped RNA reveals adaptable mRNA binding and mechanisms for sensing N1 and N2 ribose 2′-O methylations

PubMed Central

Laudenbach, Beatrice Theres; Martínez-Montero, Saúl; Cencic, Regina; Habjan, Matthias; Pichlmair, Andreas; Damha, Masad J.; Pelletier, Jerry; Nagar, Bhushan

2017-01-01

IFIT1 (IFN-induced protein with tetratricopeptide repeats-1) is an effector of the host innate immune antiviral response that prevents propagation of virus infection by selectively inhibiting translation of viral mRNA. It relies on its ability to compete with the translation initiation factor eIF4F to specifically recognize foreign capped mRNAs, while remaining inactive against host mRNAs marked by ribose 2′-O methylation at the first cap-proximal nucleotide (N1). We report here several crystal structures of RNA-bound human IFIT1, including a 1.6-Å complex with capped RNA. IFIT1 forms a water-filled, positively charged RNA-binding tunnel with a separate hydrophobic extension that unexpectedly engages the cap in multiple conformations (syn and anti) giving rise to a relatively plastic and nonspecific mode of binding, in stark contrast to eIF4E. Cap-proximal nucleotides encircled by the tunnel provide affinity to compete with eIF4F while allowing IFIT1 to select against N1 methylated mRNA. Gel-shift binding assays confirm that N1 methylation interferes with IFIT1 binding, but in an RNA-dependent manner, whereas translation assays reveal that N1 methylation alone is not sufficient to prevent mRNA recognition at high IFIT1 concentrations. Structural and functional analysis show that 2′-O methylation at N2, another abundant mRNA modification, is also detrimental for RNA binding, thus revealing a potentially synergistic role for it in self- versus nonself-mRNA discernment. Finally, structure-guided mutational analysis confirms the importance of RNA binding for IFIT1 restriction of a human coronavirus mutant lacking viral N1 methylation. Our structural and biochemical analysis sheds new light on the molecular basis for IFIT1 translational inhibition of capped viral RNA. PMID:28251928

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

Bis[μ-N-(tert-butyl­dimethyl­silyl)-N-(pyridin-2-ylmeth­yl)amido]­bis­[methyl­cobalt(II)

PubMed Central

Malassa, Astrid; Agthe, Christine; Görls, Helmar; Westerhausen, Matthias

2012-01-01

The green title complex, [Co2(CH3)2(C12H21N2Si)2], was obtained from bis­{[μ-N-tert-butyl­dimethyl­silyl-N-(pyridin-2-ylmeth­yl)amido]­chloridocobalt(II)} and methyl­lithium in diethyl ether at 195 K via a metathesis reaction. The dimeric cobalt(II) complex exhibits a crystallographic center of inversion in the middle of the Co2N2 ring (average Co—N = 2.050 Å). The CoII atom shows a distorted tetra­hedral coordination sphere. The exocyclic Co—N bond length to the pyridyl group shows a similar value of 2.045 (4) Å. The exocyclic methyl group has a rather long Co—C bond length of 2.019 (5) Å. PMID:22969464

Global DNA methylation in fetal human germ cells and germ cell tumours: association with differentiation and cisplatin resistance.

PubMed

Wermann, Hendrik; Stoop, Hans; Gillis, Ad J M; Honecker, Friedemann; van Gurp, Ruud J H L M; Ammerpohl, Ole; Richter, Julia; Oosterhuis, J Wolter; Bokemeyer, Carsten; Looijenga, Leendert H J

2010-08-01

Differences in the global methylation pattern, ie hyper- as well as hypo-methylation, are observed in cancers including germ cell tumours (GCTs). Related to their precursor cells, GCT methylation status differs according to histology. We investigated the methylation pattern of normal fetal, infantile, and adult germ cells (n = 103) and GCTs (n = 251) by immunohistochemical staining for 5-(m)cytidine. The global methylation pattern of male germ cells changes from hypomethylation to hypermethylation, whereas female germ cells remain unmethylated at all stages. Undifferentiated GCTs (seminomas, intratubular germ cell neoplasia unclassified, and gonadoblastomas) are hypomethylated, whereas more differentiated GCTs (teratomas, yolk sac tumours, and choriocarcinomas) show a higher degree of methylation. Embryonal carcinomas show an intermediate pattern. Resistance to cisplatin was assessed in the seminomatous cell line TCam-2 before and after demethylation using 5-azacytidine. Exposure to 5-azacytidine resulted in decreased resistance to cisplatin. Furthermore, after demethylation, the stem cell markers NANOG and POU5F1 (OCT3/4), as well as the germ cell-specific marker VASA, showed increased expression. Following treatment with 5-azacytidine, TCam-2 cells were analysed using a high-throughput methylation screen for changes in the methylation sites of 14,000 genes. Among the genes revealing changes, interesting targets were identified: ie demethylation of KLF11, a putative tumour suppressor gene, and hypermethylation of CFLAR, a gene previously described in treatment resistance in GCTs.

Gestational intake of methyl donors and global LINE-1 DNA methylation in maternal and cord blood

PubMed Central

Baccarelli, Andrea; Kleinman, Ken P; Burris, Heather H; Litonjua, Augusto A; Rifas-Shiman, Sheryl L; Tarantini, Letizia; Gillman, Matthew W

2012-01-01

Maternal diet affects offspring DNA methylation in animal models, but evidence from humans is limited. We investigated the extent to which gestational intake of methyl donor nutrients affects global DNA methylation in maternal and umbilical cord blood. Among mother-infant pairs in Project Viva, a folate-replete US population, we estimated maternal intakes of vitamin B12, betaine, choline, folate, cadmium, zinc and iron periconceptionally and during the second trimester. We examined associations of these nutrients with DNA methylation, measured as %5-methyl cytosines (%5mC) in Long Interspersed Nuclear Element-1 (LINE-1), in first trimester (n = 830) and second trimester (n = 671) maternal blood and in cord blood at delivery (n = 516). Cord blood methylation was higher for male than female infants {mean [standard deviation (SD)] 84.8 [0.6] vs. 84.4 [0.7]%}. In the multivariable-adjusted model, maternal intake of methyl donor nutrients periconceptionally and during the second trimester of pregnancy was not positively associated with first trimester, second trimester or cord blood LINE-1 methylation. Periconceptional betaine intake was inversely associated with cord blood methylation [regression coefficient = −0.08% (95% confidence interval (CI): −0.14, −0.01)] but this association was attenuated after adjustment for dietary cadmium, which itself was directly associated with first trimester methylation and inversely associated with cord blood methylation. We also found an inverse association between periconceptional choline [−0.10%, 95% CI: −0.17, −0.03 for each SD (∼63 mg/day)] and cord blood methylation in males only. In this folate-replete population, we did not find positive associations between intake of methyl donor nutrients during pregnancy and DNA methylation overall, but among males, higher early pregnancy intakes of choline were associated with lower cord blood methylation. PMID:22430801

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

Role of N-Methyl-D-Aspartate Receptors in Action-Based Predictive Coding Deficits in Schizophrenia.

PubMed

Kort, Naomi S; Ford, Judith M; Roach, Brian J; Gunduz-Bruce, Handan; Krystal, John H; Jaeger, Judith; Reinhart, Robert M G; Mathalon, Daniel H

2017-03-15

Recent theoretical models of schizophrenia posit that dysfunction of the neural mechanisms subserving predictive coding contributes to symptoms and cognitive deficits, and this dysfunction is further posited to result from N-methyl-D-aspartate glutamate receptor (NMDAR) hypofunction. Previously, by examining auditory cortical responses to self-generated speech sounds, we demonstrated that predictive coding during vocalization is disrupted in schizophrenia. To test the hypothesized contribution of NMDAR hypofunction to this disruption, we examined the effects of the NMDAR antagonist, ketamine, on predictive coding during vocalization in healthy volunteers and compared them with the effects of schizophrenia. In two separate studies, the N1 component of the event-related potential elicited by speech sounds during vocalization (talk) and passive playback (listen) were compared to assess the degree of N1 suppression during vocalization, a putative measure of auditory predictive coding. In the crossover study, 31 healthy volunteers completed two randomly ordered test days, a saline day and a ketamine day. Event-related potentials during the talk/listen task were obtained before infusion and during infusion on both days, and N1 amplitudes were compared across days. In the case-control study, N1 amplitudes from 34 schizophrenia patients and 33 healthy control volunteers were compared. N1 suppression to self-produced vocalizations was significantly and similarly diminished by ketamine (Cohen's d = 1.14) and schizophrenia (Cohen's d = .85). Disruption of NMDARs causes dysfunction in predictive coding during vocalization in a manner similar to the dysfunction observed in schizophrenia patients, consistent with the theorized contribution of NMDAR hypofunction to predictive coding deficits in schizophrenia. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Scalable synthesis and isolation of the four stereoisomers of methyl 1-amino-3-(4-bromophenyl)cyclopentanecarboxylate, useful intermediates for the synthesis of S1P1 receptor agonists.

PubMed

Wallace, Grier A; Gordon, Thomas D; Hayes, Martin E; Konopacki, Donald B; Fix-Stenzel, Shannon R; Zhang, Xiaolei; Grongsaard, Pintipa; Cusack, Kevin P; Schaffter, Lisa M; Henry, Rodger F; Stoffel, Robert H

2009-07-03

The individual isomers of methyl 1-amino-3-(4-bromophenyl)cyclopentanecarboxylate are useful intermediates for the synthesis of S1P1 receptor agonists. Herein we describe a scalable synthesis and isolation of each of the four stereoisomers of this compound in gram quantities with >98% ee and de. The utility of this approach is demonstrated by the synthesis of ((1R,3R)-1-amino-3-(4-octylphenyl)cyclopentyl)methanol in 7 steps, 11% overall yield, and >98% ee and de.

Crystal structure of N,N,N′,N′,N′′,N′′-hexa­methyl­guanidinium cyanate 1.5-hydrate

PubMed Central

Tiritiris, Ioannis; Kantlehner, Willi

2015-01-01

The title hydrated salt, C7H18N3 +·OCN−.1.5H2O, was synthesized starting from N,N,N′,N′,N′′,N′′-hexa­methyl­guanidinium chloride by a twofold anion-exchange reaction. The asymmetric unit contains two cations, two cyanate anions and three water mol­ecules. One cation shows orientational disorder and two sets of N-atom positions were found related by a 60° rotation, with an occupancy ratio of 0.852 (6):0.148 (6). The C—N bond lengths in both guanidin­ium ions range from 1.329 (2) to 1.358 (10) Å, indicating double-bond character, pointing towards charge delocalization within the NCN planes. Strong O—H⋯N hydrogen bonds between the crystal water mol­ecules and the cyanate ions and strong O—H⋯O hydrogen bonds between the water mol­ecules are present, resulting in a two-dimensional hydrogen bonded network running parallel to the (001) plane. The hexa­methyl­guanidinium ions are packed in between the layers built up by water mol­ecules and cyanate ions. PMID:26870506

TIME-COURSE OF ACUTE NEUROTOXICITY PRODUCED BY N-METHYL CARBAMATES IN PREWEANLING RATS.

EPA Science Inventory

N-methyl carbamate insecticides are reversible inhibitors of central and peripheral acetylcholinesterease (ChE). Despite their widespread and long-term use, we could find no studies of a systematic comparison of neurotoxicity in young animals across this group of chemicals. To ...

NEURAL AND CARDIAC TOXICITIES ASSOCIATED WITH 3,4-METHYLENEDIOXYMETHAMPHETAMINE (MDMA)

PubMed Central

Baumann, Michael H.; Rothman, Richard B.

2011-01-01

(±)-3,4-Methylenedioxymethamphetamine (MDMA) is a commonly abused illicit drug which affects multiple organ systems. In animals, high-dose administration of MDMA produces deficits in serotonin (5-HT) neurons (e.g., depletion of forebrain 5-HT) that have been viewed as neurotoxicity. Recent data implicate MDMA in the development of valvular heart disease (VHD). The present paper reviews several issues related to MDMA-associated neural and cardiac toxicities. The hypothesis of MDMA neurotoxicity in rats is evaluated in terms of the effects of MDMA on monoamine neurons, the use of scaling methods to extrapolate MDMA doses across species, and functional consequences of MDMA exposure. A potential treatment regimen (l-5-hydroxytryptophan plus carbidopa) for MDMA-associated neural deficits is discussed. The pathogenesis of MDMA-associated VHD is reviewed with specific reference to the role of valvular 5-HT2B receptors. We conclude that pharmacological effects of MDMA occur at the same doses in rats and humans. High doses of MDMA that produce 5-HT depletions in rats are associated with tolerance and impaired 5-HT release. Doses of MDMA that fail to deplete 5-HT in rats can cause persistent behavioral dysfunction, suggesting even moderate doses may pose risks. Finally, the MDMA metabolite, 3,4-methylenedioxyamphetamine (MDA), is a potent 5-HT2B agonist which could contribute to the increased risk of VHD observed in heavy MDMA users. PMID:19897081

Modification of N6-methyladenosine RNA methylation on heat shock protein expression.

PubMed

Yu, Jiayao; Li, Yi; Wang, Tian; Zhong, Xiang

2018-01-01

This study was conducted to investigate effect of N6-methyladenosine (m6A) RNA methylation on Heat shock proteins (HSPs) and dissect the profile of HSP RNA methylation. The results showed that m6A methyltransferases METTL3 mRNA was decreased in responses to heat shock stress in HepG2 cells, but m6A-specific binding protein YTHDF2 mRNA was upregulated in a manner similar to HSP70 induction. Immunofluorescence staining showed that the majority of YTHDF2 was present in the cytosol, however, nearly all YTHDF2 translocated from the cytosol into the nucleus after heat shock. METTL3 knockdown significantly changed HSP70, HSP60, and HSP27 mRNA expression in HepG2 cells using siRNA, however, mRNA lifetime was not impacted. Silence of YTHDF2 using siRNA did not change expression of HSP70, but significantly increased HSP90, HSP60, and HSPB1 mRNA expression. In addition, m6A-seq revealed that HSP m6A methylation peaks are mainly enriched on exons and around stop codons, and shows a unique distribution profile in the 5'UTR and 3'UTR. Knockdown of METTL3 changed the methylation patterns of HSPs transcript. In conclusion, m6A RNA methylation regulates HSP gene expression. Differential expression of HSPs modulated by m6A may depend on the m6A site and abundance of the target gene. This finding provides insights into new regulatory mechanisms of HSPs in normal and stress situations.

Direct detection of methylation in genomic DNA

PubMed Central

Bart, A.; van Passel, M. W. J.; van Amsterdam, K.; van der Ende, A.

2005-01-01

The identification of methylated sites on bacterial genomic DNA would be a useful tool to study the major roles of DNA methylation in prokaryotes: distinction of self and nonself DNA, direction of post-replicative mismatch repair, control of DNA replication and cell cycle, and regulation of gene expression. Three types of methylated nucleobases are known: N6-methyladenine, 5-methylcytosine and N4-methylcytosine. The aim of this study was to develop a method to detect all three types of DNA methylation in complete genomic DNA. It was previously shown that N6-methyladenine and 5-methylcytosine in plasmid and viral DNA can be detected by intersequence trace comparison of methylated and unmethylated DNA. We extended this method to include N4-methylcytosine detection in both in vitro and in vivo methylated DNA. Furthermore, application of intersequence trace comparison was extended to bacterial genomic DNA. Finally, we present evidence that intrasequence comparison suffices to detect methylated sites in genomic DNA. In conclusion, we present a method to detect all three natural types of DNA methylation in bacterial genomic DNA. This provides the possibility to define the complete methylome of any prokaryote. PMID:16091626

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.

Data-derived uncertainty factor approach in the revised N-methyl carbamate risk assessment.

EPA Science Inventory

EPA completed its Revised Cumulative Risk Assessment (CRA) of the N-methyl Carbamate (NMC) Pesticides in 2007. This assessment evaluated the joint risk to 10 pesticides from food, water, and residential exposure. NMCs share the ability to inhibit acetylcholinesterase (AChE) via c...

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.

SPE-GC/FTD determination of N-methyl-2-pyrrolidone and its metabolites in urine.

PubMed

Kubota, Ryuichi; Endo, Yoko; Takeuchi, Akito; Inoue, Yoshinori; Ogata, Hiroko; Ogawa, Masanori; Nakagawa, Tomoo; Onda, Nobuhiko; Endo, Ginji

2007-07-01

An analytical method using a combination of solid-phase extraction (SPE) and gas chromatography with a flame thermionic detector (GC/FTD) was developed for determination of N-methyl-2-pyrrolidone (NMP), N-methylsuccinimide (MSI), and 2-hydroxy-N-methylsuccinimide (2-HMSI) in human urine. The SPE cartridge of poly(divinylbenzene/hydroxymethacrylate) used was directly loaded with urine sample, followed by elution with methyl isobutyl ketone (MIBK) and subsequent centrifugation, and the supernatant was injected into the capillary GC using a DB1701. This method allowed efficient separation of NMP, MSI, and 2-HMSI, which were nearly free of interference by other GC peaks arising from urine. Recoveries of NMP, MSI, and 2-HMSI from the SPE cartridge were about 98, 101, and 67%, respectively, with limits of detection of 0.04, 0.02, and 0.06 mg/L, respectively, which met the regulatory requirements. The present method was used for assay in biological monitoring of workers exposed to NMP in their occupational environment.

Synthesis, structural elucidation and pharmacological properties of some 5-acetyl-3,4-dihydro-6-methyl-4-(substituted phenyl)-2(1H) -pyrimidinones.

PubMed

Yarim, M; Sarac, S; Ertan, M; Batu, O S; Erol, K

1999-06-30

In this study, the synthesis of some new 5-acetyl-3,4-dihydro-6-methyl-4-(substituted phenyl)-2(1H)-pyrimidinones has been reported. The compounds were prepared by the Biginelli reaction of acetylacetone with aromatic aldehydes and urea. The structures of the compounds were characterized by UV, IR, 1H NMR, 13C NRM, mass spectra and elementary analysis. The calcium antagonistic activity of these compounds was tested in vitro on rat ileum precontracted with 4 x 10(-3) M barium chloride.

Antimutagenic components in Glycyrrhiza against N-methyl-N-nitrosourea in the Ames assay.

PubMed

Inami, Keiko; Mine, Yusuke; Kojo, Yukiko; Tanaka, Satomi; Ishikawa, Satoko; Mochizuki, Masataka

2017-03-01

Antimutagenesis against N-nitroso compounds contribute to prevention of human cancer. We have found that Glycyrrhiza aspera ethanolic extract exhibits antimutagenic activity against N-methyl-N-nitrosourea (MNU) using the Ames assay with Salmonella typhimurium TA1535. In the present study, eight purified components from Glycyrrhiza, namely glabridin, glycyrrhetinic acid, glycyrrhizin, licochalcone A, licoricesaponin H2, licoricesaponin G2, liquiritigenin and liquiritin were evaluated for their antimutagenicity against MNU in the Ames assay with S. typhimurium TA1535. Glycyrrhetinic acid, glycyrrhizin, licoricesaponin G2, licoricesaponin H2 and liquiritin did not show the antimutagenicity against MNU in S. typhimurium TA1535. Glabridin, licochalcone A and liquiritigenin reduced revertant colonies derived from MNU in S. typhimurium TA1535 without showing cytotoxic effects, indicating that these compounds possess antimutagenic activity against MNU. The inhibitory activity of glabridin and licochalcone A was more effective than that of liquiritigenin. Thus, Glycyrrhiza contains antimutagenic components against DNA alkylating, direct-acting carcinogens.

Novel Selectivity-Based Forensic Toxicological Validation of a Paper Spray Mass Spectrometry Method for the Quantitative Determination of Eight Amphetamines in Whole Blood.

PubMed

Teunissen, Sebastiaan F; Fedick, Patrick W; Berendsen, Bjorn J A; Nielen, Michel W F; Eberlin, Marcos N; Graham Cooks, R; van Asten, Arian C

2017-12-01

Paper spray tandem mass spectrometry is used to identify and quantify eight individual amphetamines in whole blood in 1.3 min. The method has been optimized and fully validated according to forensic toxicology guidelines, for the quantification of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxy-N-methylamphetamine (MDMA), 3,4-methylenedioxy-N-ethylamphetamine (MDEA), para-methoxyamphetamine (PMA), para-methoxymethamphetamine (PMMA), and 4-fluoroamphetamine (4-FA). Additionally, a new concept of intrinsic and application-based selectivity is discussed, featuring increased confidence in the power to discriminate the amphetamines from other chemically similar compounds when applying an ambient mass spectrometric method without chromatographic separation. Accuracy was within ±15% and average precision was better than 15%, and better than 20% at the LLOQ. Detection limits between 15 and 50 ng/mL were obtained using only 12 μL of whole blood. Graphical abstract ᅟ.

Novel Selectivity-Based Forensic Toxicological Validation of a Paper Spray Mass Spectrometry Method for the Quantitative Determination of Eight Amphetamines in Whole Blood

NASA Astrophysics Data System (ADS)

Teunissen, Sebastiaan F.; Fedick, Patrick W.; Berendsen, Bjorn J. A.; Nielen, Michel W. F.; Eberlin, Marcos N.; Graham Cooks, R.; van Asten, Arian C.

2017-12-01

Paper spray tandem mass spectrometry is used to identify and quantify eight individual amphetamines in whole blood in 1.3 min. The method has been optimized and fully validated according to forensic toxicology guidelines, for the quantification of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxy- N-methylamphetamine (MDMA), 3,4-methylenedioxy- N-ethylamphetamine (MDEA), para-methoxyamphetamine (PMA), para-methoxymethamphetamine (PMMA), and 4-fluoroamphetamine (4-FA). Additionally, a new concept of intrinsic and application-based selectivity is discussed, featuring increased confidence in the power to discriminate the amphetamines from other chemically similar compounds when applying an ambient mass spectrometric method without chromatographic separation. Accuracy was within ±15% and average precision was better than 15%, and better than 20% at the LLOQ. Detection limits between 15 and 50 ng/mL were obtained using only 12 μL of whole blood. [Figure not available: see fulltext.

Glycerol as a Building Block for Prochiral Aminoketone, N-Formamide, and N-Methyl Amine Synthesis.

PubMed

Dai, Xingchao; Rabeah, Jabor; Yuan, Hangkong; Brückner, Angelika; Cui, Xinjiang; Shi, Feng

2016-11-23

Prochiral aminoketones are key intermediates for the synthesis of optically active amino alcohols, and glycerol is one of the main biomass-based alcohols available in industry. In this work, glycerol was catalytically activated and purposefully converted with amines to generate highly valuable prochiral aminoketones, as well as N-formamides and N-methyl amines, over CuNiAlO x catalyst. The catalyst structure can be anticipated as nano-Ni species on or in CuAlO x via the formation of nano- Cu-Ni alloy particles. This concept may present a novel and valuable methodology for glycerol utilization. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Alkylation of deoxyribonucleic acid by carcinogens dimethyl sulphate, ethyl methanesulphonate, N-ethyl-N-nitrosourea and N-methyl-N-nitrosourea. Relative reactivity of the phosphodiester site thymidylyl(3'-5')thymidine.

PubMed Central

Swenson, D H; Lawley, P D

1978-01-01

1. The ethyl phosphotriester of thymidylyl(3'-5')thymidine, dTp(Et)dT, was identified as a product from reaction of DNA with N-ethyl-N-nitrosourea, by procedures parallel to those reported previously for the methyl homologue produced by N-methyl-N-nitrosourea. 2. Enzymic degradation to yield alkyl phosphotriesters from DNA alkylated by these carcinogens and by dimethyl sulphate and ethyl methanesulphonate was studied quantitatively, and the relative yields of the triesters dTp(Alk)dT were determined. The relative reactivity of the phosphodiester group dTpdT to each of the four carcinogens was thus obtained, and compared with that of DNA overall, or with that of the N-7 atom of guanine in DNA. Relative reactivity of the phosphodiester group was lowest towards dimethyl sulphate, the least electrophilic of the reagents used, and was highest towards N-ethyl-N-nitrosourea, the most electrophilic reagent. 3. The nature of the alkyl group transferred also influenced reactivity of the phosphodiester site, since this site was relatively more reactive towards ethylation than would be predicted simply from the known Swain-Scott s values of the alkylating agents. It was therefore suggested that the steric accessibility of the weakly nucleophilic phosphodiester group on the outside of the DNA macromolecule favours its reaction with ethylating, as opposed to methylating, reagents. 4. Taking a value of the Swain-Scott nucleophilicity (n) of 2.5 for an average DNA nucleotide unit [Walles & Ehrenberg (1969) Acta Chem. Scand. 23, 1080-1084], a value of n of about 1 for the phosphodiester group was deduced, and this value was found to be 2-3 units less than that for the N-7 atom of guanine in DNA. 5. The reactivity of DNA overall was markedly high towards the alkylnitrosoureas, despite their relatively low s values. This was ascribed to an electrostatic factor that favoured reaction of the negatively charged polymer with alkyldiazonium cation intermediates. PMID:208508

Epigenome-wide association study of smoking and DNA methylation in non-small cell lung neoplasms.

PubMed

Freeman, Joshua R; Chu, Su; Hsu, Thomas; Huang, Yen-Tsung

2016-10-25

Tobacco smoke is a well-established lung cancer carcinogen. We hypothesize that epigenetic processes underlie carcinogenesis. The objective of this study is to examine the effects of smoke exposure on DNA methylation to search for novel susceptibility loci. We obtained epigenome-wide DNA methylation data from lung adenocarcinoma (LUAD) and lung squamous cell (LUSC) tissues in The Cancer Genome Atlas (TCGA). We performed a two-stage discovery (n = 326) and validation (n = 185) analysis to investigate the association of epigenetic DNA methylation level with cigarette smoking pack-years. We also externally validated our findings in an independent dataset. Linear model with least square estimator and spline regression were performed to examine the association between DNA methylation and smoking. We identified five CpG sites highly associated with pack-years of cigarette smoking. Smoking was negatively associated with methylation levels in cg25771041 (WWTR1, p = 3.6 × 10-9), cg16200496 (NFIX, p = 3.4 × 10-12), cg22515201 (PLA2G6, p = 1.0 × 10-9) and cg24823993 (NHP2L1, p = 5.1 × 10-8) and positively associated with the methylation level in cg11875268 (SMUG1, p = 4.3 × 10-8). The CpG-smoking association was stronger in LUSC than LUAD. Of the five loci, smoking explained the most variation in cg16200496 (R2 = 0.098 [both types] and 0.144 [LUSC]). We identified 5 novel CpG candidates that demonstrate differential methylation patterns associated with smoke exposure in lung neoplasms.

Distribution and elimination of the glycosidase inhibitors 1-deoxymannojirimycin and N-methyl-1-deoxynojirimycin in the rat in vivo.

PubMed

Faber, E D; Oosting, R; Neefjes, J J; Ploegh, H L; Meijer, D K

1992-11-01

We studied the pharmacokinetics of two synthetic derivatives of 1-deoxynojirimycin in the rat after intravenous administration. The mannosidase IA/B inhibitor 1-deoxymannojirimycin and the glucosidase inhibitor N-methyl-1-deoxynojirimycin exhibited minimal plasma protein binding and showed a rapid biphasic plasma disappearance, with an initial t1/2 of 3.0 and 4.5 min, respectively, and a terminal t1/2 of 51 and 32 min, respectively. For both compounds renal excretion is the major route of elimination. After 120 min, 52% of the dose of 1-deoxymannojirimycin and 80% of the dose of N-methyl-1-deoxymannojirimycin was recovered unchanged from the urine, whereas only 4.9 and 0.2%, respectively, of the dose was excreted in bile. Urinary clearance of 1-deoxymannojirimycin was similar to the glomerular filtration rate. In contrast, urinary clearance of N-methyl-1-deoxynojirimycin was two to three times higher than the glomerular filtration rate, indicating active tubular secretion. Ligation of the renal vessels decreased the total-body clearance of 1-deoxymannojirimycin and N-methyl-1-deoxynojirimycin 18- and 24-fold, respectively. Neither alkalinization of the urine by infusion of bicarbonate solutions nor forced diuresis altered the renal excretion rate of these compounds, implying the absence of tubular reabsorption. At 120 min, the amounts of 1-deoxymannojirimycin in liver and kidney were 2.1 and 1.1% of the dose, respectively, while small intestine, stomach, and heart contained only 0.9, 0.6 and 0.1%. Less than 1% of the dose of N-methyl-1-deoxynojirimycin was found in the collected organs 2 hr after injection.(ABSTRACT TRUNCATED AT 250 WORDS)

Time-course, dose-response, and age comparative sensitivity of N-methyl carbamates in rats

EPA Science Inventory

N-Methyl carbamate insecticides are reversible inhibitors of central and peripheral acetylcholinesterease (ChE). Despite their widespread use, there are few studies of neurotoxicity in young animals. To study potential age-related differences, we evaluated seven carbamates (carba...

Propofol effectively inhibits lithium-pilocarpine- induced status epilepticus in rats via downregulation of N-methyl-D-aspartate receptor 2B subunit expression

PubMed Central

Wang, Henglin; Wang, Zhuoqiang; Mi, Weidong; Zhao, Cong; Liu, Yanqin; Wang, Yongan; Sun, Haipeng

2012-01-01

Status epilepticus was induced via intraperitoneal injection of lithium-pilocarpine. The inhibitory effects of propofol on status epilepticus in rats were judged based on observation of behavior, electroencephalography and 24-hour survival rate. Propofol (12.5–100 mg/kg) improved status epilepticus in a dose-dependent manner, and significantly reduced the number of deaths within 24 hours of lithium-pilocarpine injection. Western blot results showed that, 24 hours after induction of status epilepticus, the levels of N-methyl-D-aspartate receptor 2A and 2B subunits were significantly increased in rat cerebral cortex and hippocampus. Propofol at 50 mg/kg significantly suppressed the increase in N-methyl-D-aspartate receptor 2B subunit levels, but not the increase in N-methyl-D-aspartate receptor 2A subunit levels. The results suggest that propofol can effectively inhibit status epilepticus induced by lithium-pilocarpine. This effect may be associated with downregulation of N-methyl-D-aspartate receptor 2B subunit expression after seizures. PMID:25737709

Top-Contact Pentacene-Based Organic Thin Film Transistor (OTFT) with N, N'-Bis(3-Methyl Phenyl)- N, N'-Diphenyl Benzidine (TPD)/Au Bilayer Source-Drain Electrode

NASA Astrophysics Data System (ADS)

Borthakur, Tribeni; Sarma, Ranjit

2018-01-01

A top-contact Pentacene-based organic thin film transistor (OTFT) with N, N'-Bis (3-methyl phenyl)- N, N'-diphenyl benzidine (TPD)/Au bilayer source-drain electrode is reported. The devices with TPD/Au bilayer source-drain (S-D) electrodes show better performance than the single layer S-D electrode OTFT devices. The field-effect mobility of 4.13 cm2 v-1 s-1, the on-off ratio of 1.86 × 107, the threshold voltage of -4 v and the subthreshold slope of .27 v/decade, respectively, are obtained from the device with a TPD/Au bilayer source-drain electrode.

The preference of tryptophan for membrane interfaces: insights from N-methylation of tryptophans in gramicidin channels.

PubMed

Sun, Haiyan; Greathouse, Denise V; Andersen, Olaf S; Koeppe, Roger E

2008-08-08

To better understand the structural and functional roles of tryptophan at the membrane/water interface in membrane proteins, we examined the structural and functional consequences of Trp --> 1-methyl-tryptophan substitutions in membrane-spanning gramicidin A channels. Gramicidin A channels are miniproteins that are anchored to the interface by four Trps near the C terminus of each subunit in a membrane-spanning dimer. We masked the hydrogen bonding ability of individual or multiple Trps by 1-methylation of the indole ring and examined the structural and functional changes using circular dichroism spectroscopy, size exclusion chromatography, solid state (2)H NMR spectroscopy, and single channel analysis. N-Methylation causes distinct changes in the subunit conformational preference, channel-forming propensity, single channel conductance and lifetime, and average indole ring orientations within the membrane-spanning channels. The extent of the local ring dynamic wobble does not increase, and may decrease slightly, when the indole NH is replaced by the non-hydrogen-bonding and more bulky and hydrophobic N-CH(3) group. The changes in conformational preference, which are associated with a shift in the distribution of the aromatic residues across the bilayer, are similar to those observed previously with Trp --> Phe substitutions. We conclude that indole N-H hydrogen bonding is of major importance for the folding of gramicidin channels. The changes in ion permeability, however, are quite different for Trp --> Phe and Trp --> 1-methyl-tryptophan substitutions, indicating that the indole dipole moment and perhaps also ring size and are important for ion permeation through these channels.

Development of ferret as a human lung cancer model by injecting4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK)

USDA-ARS?s Scientific Manuscript database

Development of new animal lung cancer models that are relevant to human lung carcinogenesis is important for lung cancer research. Previously we have shown the induction of lung tumor in ferrets (Mustela putorius furo) exposed to both tobacco smoke and a tobacco carcinogen (4-(N-methyl-N-nitrosamino...

Progesterone up-regulates vasodilator effects of calcitonin gene-related peptide in N(G)-nitro-L-arginine methyl ester-induced hypertension.

PubMed

Gangula, P R; Wimalawansa, S J; Yallampalli, C

1997-04-01

We recently reported that calcitonin gene-related peptide can reverse the hypertension produced by N(G)-nitro-L-arginine methyl ester in pregnant rats. In the current study we investigated whether these vasodilator effects of calcitonin gene-related peptide were progesterone dependent. Calcitonin gene-related peptide or N(G)-nitro-L-arginine methyl ester was infused through osmotic minipumps, either separately or in combination, to groups of five pregnant rats from day 17 of gestation until day 8 post partum or to nonpregnant ovariectomized rats for 8 days. Progesterone was injected during days 1 to 6 post partum and for 6 days after ovariectomy. Systolic blood pressure was measured daily. Animals receiving N(G)-nitro-L-arginine methyl ester exhibited significant elevations of blood pressure during pregnancy and post partum. Coadministration of calcitonin gene-related peptide to these rats reversed the hypertension during pregnancy but not during the postpartum period. At the dose used in this study calcitonin gene-related peptide administered alone was without significant effects on blood pressure. However, it reduced both the mortality and growth restriction of the fetus associated with N(G)-nitro-L-arginine methyl ester in these animals. Calcitonin gene-related peptide reversed the hypertension in N(G)-nitro-L-arginine methyl ester-infused postpartum rats during the periods of progesterone treatment only, and these effects were lost when progesterone treatment was stopped. Neither progesterone nor calcitonin gene-related peptide alone were effective. To further confirm these observations, progesterone effects were tested in ovariectomized adult rats. Similar to the findings in postpartum rats, calcitonin gene-related peptide completely reversed the elevation in blood pressure in N(G)-nitro-L-arginine methyl ester-treated rats receiving progesterone injections. The effects of calcitonin gene-related peptide were apparent only during the progesterone treatment

Abundant Lysine Methylation and N-Terminal Acetylation in Sulfolobus islandicus Revealed by Bottom-Up and Top-Down Proteomics*

PubMed Central

Vorontsov, Egor A.; Rensen, Elena; Prangishvili, David; Krupovic, Mart; Chamot-Rooke, Julia

2016-01-01

Protein post-translational methylation has been reported to occur in archaea, including members of the genus Sulfolobus, but has never been characterized on a proteome-wide scale. Among important Sulfolobus proteins carrying such modification are the chromatin proteins that have been described to be methylated on lysine side chains, resembling eukaryotic histones in that aspect. To get more insight into the extent of this modification and its dynamics during the different growth steps of the thermoacidophylic archaeon S. islandicus LAL14/1, we performed a global and deep proteomic analysis using a combination of high-throughput bottom-up and top-down approaches on a single high-resolution mass spectrometer. 1,931 methylation sites on 751 proteins were found by the bottom-up analysis, with methylation sites on 526 proteins monitored throughout three cell culture growth stages: early-exponential, mid-exponential, and stationary. The top-down analysis revealed 3,978 proteoforms arising from 681 proteins, including 292 methylated proteoforms, 85 of which were comprehensively characterized. Methylated proteoforms of the five chromatin proteins (Alba1, Alba2, Cren7, Sul7d1, Sul7d2) were fully characterized by a combination of bottom-up and top-down data. The top-down analysis also revealed an increase of methylation during cell growth for two chromatin proteins, which had not been evidenced by bottom-up. These results shed new light on the ubiquitous lysine methylation throughout the S. islandicus proteome. Furthermore, we found that S. islandicus proteins are frequently acetylated at the N terminus, following the removal of the N-terminal methionine. This study highlights the great value of combining bottom-up and top-down proteomics for obtaining an unprecedented level of accuracy in detecting differentially modified intact proteoforms. The data have been deposited to the ProteomeXchange with identifiers PXD003074 and PXD004179. PMID:27555370

A pivotal role for reductive methylation in the de novo crystallization of a ternary complex composed of Yersinia pestis virulence factors YopN, SycN and YscB.

PubMed

Schubot, Florian D; Waugh, David S

2004-11-01

Structural studies of a ternary complex composed of the Yersina pestis virulence factors YopN, SycN and YscB were initially hampered by poor solubility of the individual proteins. Co-expression of all three proteins in Escherichia coli yielded a well behaved complex, but this sample proved to be recalcitrant to crystallization. As crystallization efforts remained fruitless, even after the proteolysis-guided engineering of a truncated YopN polypeptide, reductive methylation of lysine residues was employed to alter the surface properties of the complex. The methylated complex yielded crystals that diffracted X-rays to a maximal resolution of 1.8 A. The potential utility of reductive methylation as a remedial strategy for high-throughput structural biology was further underscored by the successful modification of a selenomethionine-substituted sample.

Radiosynthesis of an opiate receptor-binding radiotracer for positron emission tomography: (C-11 methyl)-methyl-4-(N-(1-oxopropyl)-N-phenylamino)-4-piperidine carboxylate (C-11 4-carbomethoxyfentanyl)

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

Dannals, R.F.; Ravert, H.T.; Frost, J.J.

The development of high affinity, high specific activity tritium-labeled neurotransmitter receptor ligands has made it possible to determine the spatial distribution and relative regional concentration of several neuroreceptors by means of in vivo receptor labeling techniques in animals. This development made possible the biochemical identification of opiate receptors by autoradiographic visualization in experimental animals. The quantitation and localization of opiate receptors in man using non-invasive methods, such as positron emission tomography, could provide a means of obtaining information about a variety of receptor-linked neuropsychiatric diseases as well as normal brain mechanisms regulating pain and emotions. As part of a continuingmore » program to identify and radiolabel high affinity, highly specific ligands for the opiate receptor, the authors have selected two derivatives of fentanyl, a well-known analgesic, as candidates for radiolabeling: R-31,833 (4-carbomethoxy-fentanyl) and R-34,995 (lofentanil). Carbon-11 labeled R-31,833 was synthesized by the methylation of the appropriate carboxylate with C-11 methyl iodide in dimethylformamide at room temperature and purified by high performance liquid chromatography. The average synthesis time from end-of-bombardment (E.O.B.) was 30 minutes. The average specific activity was determined by ultraviolet spectroscopy to be 890 mCi/..mu..mole end-of-synthesis (approx. 2500 mCi/..mu..mole E.O.B.).« less

COMPARISON OF ACUTE NEUROBEHAVIORAL AND CHOLINESTERASE INHIBITORY EFFECTS OF N-METHYL CARBAMATES IN RAT

EPA Science Inventory

There are few studies evaluating direct functional and biochemical consequences of exposure. In the present study of the acute toxicity of seven N-methyl carbamate pesticides, we evaluated the dose-response profiles of cholinesterase (ChE) inhibition in brain and erythrocytes (R...

Methylenetetrahydrofolate reductase (MTHFR) polymorphisms and promoter methylation in cervical oncogenic lesions and cancer

PubMed Central

Botezatu, Anca; Socolov, Demetra; Iancu, Iulia V; Huica, Irina; Plesa, Adriana; Ungureanu, Carmen; Anton, Gabriela

2013-01-01

The aim of this study was to investigate the role of methylenetetrahydrofolate reductase (MTHFR) polymorphisms and MTHFR methylation pattern in cervical lesions development among women from Romania, a country with high prevalence of human papillomavirus (HPV) cervical infections. To achieve this goal, blood samples and cervical cytology specimens (n = 77)/tumour tissue specimens (n = 23) were investigated. As control, blood and negative cytological smears (n = 50) were used. A statistically significant association was found between T allele of C677T polymorphism and cervical lesions, heterozygote women presenting a threefold increased risk (normal/cervical lesions and tumours: wild homozygote 34/41 (0.68/0.41), heterozygote 14/51 (0.28/0.51), mutant homozygote 2/8 (0.04/0.08); OR = 3.081, P = 0.0035). Using χ square test for the control group, the HPV-negative and HPV-positive patients with cervix lesions, a significant correlation between viral infection and T allele of C677T polymorphism (P = 0.0287) was found. The MTHFR promoter was methylated in all HGSIL and tumour samples, significant differences being noted between HPV-positive samples, control group and cases of cervical dysplastic lesions without HPV DNA (P < 0. 0001) and between samples from patients with high-risk (hr)HPV versus low-risk (lr)HPV (P = 0.0026). No correlations between polymorphisms and methylation were observed. In Romania, individuals carrying T allele are susceptible for cervical lesions. MTHFR promoter methylation is associated with cervical severity lesions and with hrHPV. PMID:23444906

3. N elevation, E wing; 3/4 view of W wing ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. N elevation, E wing; 3/4 view of W wing showing E and N elevations; N elevation of Building 69, Plating and Tinning Shop; looking SW. (Ceronie) - Rock Island Arsenal, Building No. 66, Rodman Avenue between Third & Fourth Streets, Rock Island, Rock Island County, IL

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.

Small Molecule Reversible Inhibitors of Bruton’s Tyrosine Kinase (BTK): Structure–Activity Relationships Leading to the Identification of 7-(2-Hydroxypropan-2-yl)-4-[2-methyl-3-(4-oxo-3,4-dihydroquinazolin-3-yl)phenyl]-9 H -carbazole-1-carboxamide (BMS-935177)

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

De Lucca, George V.; Shi, Qing; Liu, Qingjie

Bruton’s tyrosine kinase (BTK) belongs to the TEC family of nonreceptor tyrosine kinases and plays a critical role in multiple cell types responsible for numerous autoimmune diseases. This article will detail the structure–activity relationships (SARs) leading to a novel second generation series of potent and selective reversible carbazole inhibitors of BTK. With an excellent pharmacokinetic profile as well as demonstrated in vivo activity and an acceptable safety profile, 7-(2-hydroxypropan-2-yl)-4-[2-methyl-3-(4-oxo-3,4-dihydroquinazolin-3-yl)phenyl]-9H-carbazole-1-carboxamide 6 (BMS-935177) was selected to advance into clinical development.

Study of the n-methyl-d-aspartate antagonistic properties of anticholinergic drugs

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

McDonough, J.H.; Shih, T.M.

1995-12-31

A study of the N-methyl-D-aspartate antagonistic properties of anticholinergic drugs. PHARMACOL BIOCHEM BEHAV. 51(2/3) 249-253, 1995. Drugs that act at the N-methyl-D-aspartate (NMDA) receptor complex have the ability to terminate nerve agent-induced seizures and modulate the neuropathologic consequences of agent exposure. Drugs with mixed anticholinergic and anti-NMDA properties potentially provide an ideal class of compounds for development as anticonvulsant treatments for nerve agent casualties. The present experiment evaluated the potential NMDA antagonist activity of 11 anticholinergic drugs by determining whether pretreatment with the compound was capable of protecting mice from the lethal effects of NMDA. The following anticholinergic drugs antagonizedmore » NMDA lethality and are ranked according to their potency: mecamylamine > procyclidine = benactyzine > biperiden > tribexyphenidyl. The anticholinergics atropine, aprophen, azaprophen, benztropine, 3-quinudidinyl benzilate (QNB), and scopolamine failed to show NMDA antagonist properties. In addition, and unexpectedly, diazepam, ethanol, and pentobarbital were also shown to be capable of antagonizing NMDA lethality over a certain range of doses. The advantages and limitations of using antagonism of NMDA lethality in mice as a bioassay for determining the NMDA antagonist properties of drugs are also discussed.« less

Structural Basis for Methyl Transfer by a Radical SAM Enzyme

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

Boal, Amie K.; Grove, Tyler L.; McLaughlin, Monica I.

2014-10-02

The radical S-adenosyl-l-methionine (SAM) enzymes RlmN and Cfr methylate 23S ribosomal RNA, modifying the C2 or C8 position of adenosine 2503. The methyl groups are installed by a two-step sequence involving initial methylation of a conserved Cys residue (RlmN Cys{sup 355}) by SAM. Methyl transfer to the substrate requires reductive cleavage of a second equivalent of SAM. Crystal structures of RlmN and RlmN with SAM show that a single molecule of SAM coordinates the [4Fe-4S] cluster. Residue Cys{sup 355} is S-methylated and located proximal to the SAM methyl group, suggesting the SAM that is involved in the initial methyl transfermore » binds at the same site. Thus, RlmN accomplishes its complex reaction with structural economy, harnessing the two most important reactivities of SAM within a single site.« less

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

Proline derivatives in fruits of bergamot (Citrus bergamia Risso et Poit): presence of N-methyl-L-proline and 4-hydroxy-L-prolinebetaine.

PubMed

Servillo, Luigi; Giovane, Alfonso; Balestrieri, Maria Luisa; Cautela, Domenico; Castaldo, Domenico

2011-01-12

The content of proline and various compounds deriving from its metabolism (4-hydroxy-L-proline, N-methyl-L-proline, N,N-dimethylproline, and 4-hydroxy-L-prolinebetaine) was determined in fruits and seeds of Bergamot (Citrus bergamia Risso et Poit), growing in the Calabria region (South Italy). A HPLC-ESI-tandem mass spectrometry method, which allowed rapid determination of L-proline, 4-hydroxy-L-proline, N-methyl-L-proline, N,N-dimethylproline, and 4-hydroxy-L-prolinebetaine in juice and extracts of bergamot fruit with minimum sample preparation and short analysis time (about 10 min), is presented. Proline and 4-hydroxy-L-proline levels in the samples were also determined by HPLC analysis with fluorescence detection and the results compared to those obtained with HPLC-ESI-tandem mass spectrometry. For the first time, the presence of N-methyl-L-proline and 4-hydroxy-L-prolinebetaine in the fruits of a plant of the Citrus genus is reported.

Methylated spirit burns: an ongoing problem.

PubMed

Jansbeken, J R H; Vloemans, A F P M; Tempelman, F R H; Breederveld, R S

2012-09-01

Despite many educational campaigns we still see burns caused by methylated spirit every year. We undertook a retrospective study to analyse the impact of this problem. We retrospectively collected data of all patients with burns caused by methylated spirit over twelve years from 1996 to 2008. Our main endpoints were: incidence, age, mechanism of injury, total body surface area (TBSA) burned, burn depth, need for surgery and length of hospital stay. Ninety-seven patients with methylated spirit burns were included. During the study period there was no decrease in the number of patients annually admitted to the burn unit with methylated spirit burns. 28% of the patients (n=27) were younger than eighteen years old, 15% (n=15) were ten years old or younger. The most common cause of burns was carelessness in activities involving barbecues, campfires and fondues. Mean TBSA burned was 16% (SD 12.4). 70% (n=68) had full thickness burns. 66% (n=64) needed grafting. Mean length of hospital stay was 23 days (SD 24.7). The use of methylated spirit is an ongoing problem, which continues to cause severe burns in adults and children. Therefore methylated spirit should be banned in households. We suggest sale only in specialised shops, clear labelling and mandatory warnings. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

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

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.

Effects of Particulate Matter on Genomic DNA Methylation Content and iNOS Promoter Methylation

PubMed Central

Tarantini, Letizia; Bonzini, Matteo; Apostoli, Pietro; Pegoraro, Valeria; Bollati, Valentina; Marinelli, Barbara; Cantone, Laura; Rizzo, Giovanna; Hou, Lifang; Schwartz, Joel; Bertazzi, Pier Alberto; Baccarelli, Andrea

2009-01-01

Background Altered patterns of gene expression mediate the effects of particulate matter (PM) on human health, but mechanisms through which PM modifies gene expression are largely undetermined. Objectives We aimed at identifying short- and long-term effects of PM exposure on DNA methylation, a major genomic mechanism of gene expression control, in workers in an electric furnace steel plant with well-characterized exposure to PM with aerodynamic diameters < 10 μm (PM10). Methods We measured global genomic DNA methylation content estimated in Alu and long interspersed nuclear element-1 (LINE-1) repeated elements, and promoter DNA methylation of iNOS (inducible nitric oxide synthase), a gene suppressed by DNA methylation and induced by PM exposure in blood leukocytes. Quantitative DNA methylation analysis was performed through bisulfite PCR pyrosequencing on blood DNA obtained from 63 workers on the first day of a work week (baseline, after 2 days off work) and after 3 days of work (postexposure). Individual PM10 exposure was between 73.4 and 1,220 μg/m3. Results Global methylation content estimated in Alu and LINE-1 repeated elements did not show changes in postexposure measures compared with baseline. PM10 exposure levels were negatively associated with methylation in both Alu [β = −0.19 %5-methylcytosine (%5mC); p = 0.04] and LINE-1 [β = −0.34 %5mC; p = 0.04], likely reflecting long-term PM10 effects. iNOS promoter DNA methylation was significantly lower in postexposure blood samples compared with baseline (difference = −0.61 %5mC; p = 0.02). Conclusions We observed changes in global and gene specific methylation that should be further characterized in future investigations on the effects of PM. PMID:19270791

Association of serum N(ε)-Carboxy methyl lysine with severity of diabetic retinopathy.

PubMed

Mishra, Nibha; Saxena, Sandeep; Shukla, Rajendra K; Singh, Vinita; Meyer, Carsten H; Kruzliak, Peter; Khanna, Vinay K

2016-04-01

To correlate serum levels of N-epsilon-carboxy methyl lysine (N(ε)-CML) with severity of retinopathy, in vivo macular edema and disruption of external limiting membrane (ELM) and photoreceptor ellipsoid zone in type 2 diabetes mellitus (DM). Consecutive cases of type 2 DM [diabetes mellitus with no retinopathy (No DR) (n=20); non- proliferative diabetic retinopathy (NPDR) with diabetic macular edema (n=20); proliferative diabetic retinopathy with diabetic macular edema (PDR) (n=20)] and healthy controls (n=20) between the ages of 40 and 65 years were included (power of study=93.8%). In vivo histology of retinal layers was assessed using spectral domain optical coherence tomography. Every study subject underwent macular thickness analysis using the macular cube 512×128 feature. Disruption of ELM and photoreceptor ellipsoid zone was graded: grade 0, no disruption of ELM and ellipsoid zone; grade 1, ELM disrupted and ellipsoid zone intact; grade 2, both ELM and ellipsoid zone disrupted. Data were statistically analyzed. The mean levels of N(ε)-CML were 31.34±21.23 ng/ml, 73.88±35.01 ng/ml, 91.21±66.65 ng/ml, and 132.08±84.07 ng/ml in control, No DR, NPDR and PDR respectively. N(ε)-CML level was significantly different between the study groups (control, No DR, NPDR and PDR) (p<0.001). Mean logMAR visual acuity decreased with increased levels of N(ε)-CML (p<0.001). The association of N(Ɛ)CML with the grades of disruption was found to be statistically significant (F value=18.48, p<0.001). Univariate analysis was done with N(Ɛ)-CML as a dependent variable. The values of N(Ɛ)-CML were normalized (log10) and were subjected to univariate analysis with fasting blood glucose level, glycosylated hemoglobin, central subfield macular thickness and cube average thickness among the diseased groups (NPDR and PDR) that act as confounders. It was found that none of the variables had significant effect on N(Ɛ)-CML (fasting blood glucose p=0.12, HBA1c p=0.65, central

N-(1-Allyl-1H-indazol-5-yl)-4-methyl­benzene­sulfonamide

PubMed Central

Chicha, Hakima; Rakib, El Mostapha; Abderrafia, Hafid; Saadi, Mohamed; El Ammari, Lahcen

2013-01-01

The asymmetric unit of the title compound, C17H17N3O2S, contains two independent mol­ecules linked by an N—H⋯O hydrogen bond. The mol­ecules show different conformations. In the first mol­ecule, the fused five- and six-membered ring system is almost perpendicular to the plane through the atoms forming the allyl group, as indicated by the dihedral angle of 85.1 (4)°. The dihedral angle with the methyl­benzene­sulfonamide group is 78.8 (1)°. On the other hand, in the second mol­ecule, the dihedral angles between the indazole plane and the allyl and methyl­benzene­sulfonamide groups are 80.3 (3) and 41.5 (1)°, respectively. In the crystal, mol­ecules are further linked by N—H⋯N and C—H⋯O hydrogen bonds, forming a three-dimensional network. PMID:24454264

[N-methyl-D-aspartate receptor antibody encephalitis: value of immunomodulatory therapy].

PubMed

Le Moigno, L; Ternant, D; Paintaud, G; Thibault, G; Cloarec, S; Tardieu, M; Lagrue, E; Castelnau, P

2014-06-01

Anti-N-methyl-D-aspartate receptor (NMDA-R) encephalitis is little known to pediatricians and likely underdiagnosed. The child's vital and cognitive prognosis is at stake. The use of immunomodulatory drugs, such as rituximab has led to spectacular results, but many questions remain about its mode of action in this type of pathology. We report the case of a 6-year-old girl with no medical history, admitted for status epilepticus preceded by behavior symptoms and sleep disorders. Gradually, the child became bedridden, mute, and animated by predominantly orofacial dyskinesia. Examinations were normal (cerebrospinal fluid [CSF] analysis, brain MRI). The diagnosis was established by the presence of NMDA-R antibodies in the CSF. After exclusion of a tumor-associated syndrome, treatment was started initially by intravenous immunoglobulins, then by plasma exchange, and finally rituximab. The patient was cured with rituximab despite an unusually early recovery of the B-cell pool. Anti-N-methyl-D-aspartate receptor (NMDA-R) encephalitis is a severe but potentially reversible neurologic disorder only recently described, even in childhood. It may be reversible without sequelae if diagnosed and treated early. The use of immunomodulatory therapy, such as rituximab seemingly improves the outcome. Immunological monitoring is needed to better understand its mechanism of action in autoimmune diseases of the nervous system in childhood. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Quantitative methylation-sensitive arbitrarily primed PCR method to determine differential genomic DNA methylation in Down Syndrome.

PubMed

Chango, Abalo; Abdennebi-Najar, Latifa; Tessier, Frederic; Ferré, Séverine; Do, Sergio; Guéant, Jean-Louis; Nicolas, Jean Pierre; Willequet, Francis

2006-10-20

Relative levels of DNA hypermethylation were quantified in DS individuals using a new method based on a combination of methylation-sensitive arbitrarily primed polymerase chain reaction (MS-AP-PCR) and quantification of DNA fragments with the Agilent 2100 bioanalyzer. Four of the DS individuals had low plasma total homocysteine (tHcy) level (4.3 +/- 0.3 micromol/l) and 4 other had high-tHcy level (14.1 +/- 0.9 micromol/l). Eight healthy control individuals were matched to the DS cases for age, sex, and tHcy levels. We have identified and quantified six hypermethylated fragments. Their sizes ranged from 230-bp to 700-bp. In cases and controls, low-tHcy did not affect methylation level of identified fragments, mean methylation values were 68.0 +/- 39.7% and 52.1 +/- 40.3%, respectively. DNA methylation in DS individuals did not change significantly (59.7+/-34.5%) in response to high-tHcy level in contrast to controls (23.4 +/- 17.7%, P = 0.02). Further, the quantitative MS-AP-PCR using this microfludic system is a useful method for determining differential genomic DNA methylation.

Improving oral bioavailability of cyclic peptides by N-methylation.

PubMed

Räder, Andreas F B; Reichart, Florian; Weinmüller, Michael; Kessler, Horst

2018-06-01

The renaissance of peptides in pharmaceutical industry results from their importance in many biological functions. However, low metabolic stability and the lack of oral availability of most peptides is a certain limitation. Whereas metabolic instability may be often overcome by development of small cyclic peptides containing d-amino acids, the very low oral availability of most peptides is a serious limitation for some medicinal applications. The situation is complicated because a twofold optimization - biological activity and oral availability - is required to overcome this problem. Moreover, most simple "rules" for achieving oral availability are not general and are applicable only to limited cases. Many structural modifications for increasing biological activities and metabolic stabilities of cyclic peptides have been described, of which N-alkylation is probably the most common. This mini-review focuses on the effects of N-methylation of cyclic peptides in strategies to optimize bioavailabilities. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Intricate Effects of α-Amino and Lysine Modifications on Arginine Methylation of the N-Terminal Tail of Histone H4.

PubMed

Fulton, Melody D; Zhang, Jing; He, Maomao; Ho, Meng-Chiao; Zheng, Y George

2017-07-18

Chemical modifications of the DNA and nucleosomal histones tightly control the gene transcription program in eukaryotic cells. The "histone code" hypothesis proposes that the frequency, combination, and location of post-translational modifications (PTMs) of the core histones compose a complex network of epigenetic regulation. Currently, there are at least 23 different types and >450 histone PTMs that have been discovered, and the PTMs of lysine and arginine residues account for a crucial part of the histone code. Although significant progress has been achieved in recent years, the molecular basis for the histone code is far from being fully understood. In this study, we investigated how naturally occurring N-terminal acetylation and PTMs of histone H4 lysine-5 (H4K5) affect arginine-3 methylation catalyzed by both type I and type II PRMTs at the biochemical level. Our studies found that acylations of H4K5 resulted in decreased levels of arginine methylation by PRMT1, PRMT3, and PRMT8. In contrast, PRMT5 exhibits an increased rate of arginine methylation upon H4K5 acetylation, propionylation, and crotonylation, but not upon H4K5 methylation, butyrylation, or 2-hydroxyisobutyrylation. Methylation of H4K5 did not affect arginine methylation by PRMT1 or PRMT5. There was a small increase in the rate of arginine methylation by PRMT8. Strikingly, a marked increase in the rate of arginine methylation was observed for PRMT3. Finally, N-terminal acetylation reduced the rate of arginine methylation by PRMT3 but had little influence on PRMT1, -5, and -8 activity. These results together highlight the underlying mechanistic differences in substrate recognition among different PRMTs and pave the way for the elucidation of the complex interplay of histone modifications.

Elevated blood harmane (1-methyl-9H-pyrido[3,4-b]indole) concentrations in Parkinson's disease.

PubMed

Louis, Elan D; Michalec, Monika; Jiang, Wendy; Factor-Litvak, Pam; Zheng, Wei

2014-01-01

Parkinson's disease (PD) is a late-life neurodegenerative disease. Genetic and environmental factors play an etiological role. Harmane (1-methyl-9H-pyrido[3,4-b]indole) is a potent tremor-producing neurotoxin that shows structural resemblance to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). In 2002 and 2007, we demonstrated elevated blood harmane concentrations [HA] in essential tremor (ET) cases. We now assessed whether blood [HA] were elevated in Parkinson's disease (PD) as well. Blood [HA] were quantified by high performance liquid chromatography. Subjects comprised 113 PD cases and 101 controls. Mean log blood [HA] in PD cases was double that of controls (0.59±0.63 g(-10)/ml vs. 0.27±0.63 g(-10)/ml, p<0.001). A non-parametric test on non-transformed data (median blood [HA]=3.31 g(-10)/ml in cases and 1.44 g(-10)/ml in controls) also showed this difference (p<0.001). In unadjusted and then adjusted logistic regression analyses, log blood [HA] was associated with PD (odds ratio [OR]unadjusted 2.31, 95% confidence interval [CI] 1.46-3.67, p<0.001; OR(adjusted) 2.54, 95% CI 1.55-4.16, p<0.001). In PD, log blood [HA] co-varied with family history, being lowest in PD cases with no family history (0.54±0.60 g(-10)/ml) and highest in PD cases with a family history of both ET and PD (0.84±0.68 g(-10)/ml) (p=0.06). Blood harmane appears to be elevated in PD. The finding needs to be reproduced in additional cohorts to assess its generalizability. The higher concentration in familial PD suggests that the mechanism may involve genetic factors. Copyright © 2013 Elsevier Inc. All rights reserved.

Elevated Blood Harmane (1-methyl-9H-pyrido[3,4-b]indole) Concentrations In Parkinson's Disease

PubMed Central

Louis, Elan D.; Michalec, Monika; Jiang, Wendy; Factor-Litvak, Pam; Zheng, Wei

2014-01-01

Background Parkinson's disease (PD) is a late-life neurodegenerative disease. Genetic and environmental factors play an etiological role. Harmane (1-methyl-9H-pyrido[3,4-b]indole) is a potent tremor-producing neurotoxin that shows structural resemblance to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Objectives In 2002 and 2007, we demonstrated elevated blood harmane concentrations [HA] in essential tremor (ET) cases. We now assessed whether blood [HA] were elevated in Parkinson's disease (PD) as well. Methods Blood [HA] were quantified by high performance liquid chromatography. Subjects comprised 113 PD cases and 101 controls. Results Mean log blood [HA] in PD cases was double that of controls (0.59 ± 0.63 g −10/ml vs. 0.27 ± 0.63 g−10/ml, p <0.001). A non-parametric test on non-transformed data (median blood [HA] = 3.31 g −10/ml in cases and 1.44 g −10/ml in controls) also showed this difference (p <0.001). In unadjusted and then adjusted logistic regression analyses, log blood [HA] was associated with PD (odds ratio [OR]unadjusted 2.31, 95% confidence interval [CI] 1.46 – 3.67, p <0.001; ORadjusted 2.54, 95% CI 1.55 – 4.16, p <0.001). In PD, log blood [HA] co-varied with family history, being lowest in PD cases with no family history (0.54 ± 0.60 g−10/ml) and highest in PD cases with a family history of both ET and PD (0.84 ± 0.68 g−10/ml)(p = 0.06). Conclusions Blood harmane appears to be elevated in PD. The finding needs to be reproduced in additional cohorts to assess its generalizability. The higher concentration in familial PD suggests that the mechanism may involve genetic factors. PMID:24300779

Causes and Consequences of Flavivirus RNA Methylation.

PubMed

Bradrick, Shelton S

2017-01-01

Mosquito-borne flaviviruses are important human pathogens that represent global threats to human health. The genomes of these positive-strand RNA viruses have been shown to be substrates of both viral and cellular methyltransferases. N 7 -methylation of the 5' cap structure is essential for infection whereas 2'- O -methylation of the penultimate nucleotide is required for evasion of host innate immunity. N 6 -methylation of internal adenosine nucleotides has also been shown to impact flavivirus infection. Here, I summarize recent progress made in understanding roles for methylation in the flavivirus life-cycle and discuss relevant emerging hypotheses.

Serotonin syndrome, disseminated intravascular coagulation, and hepatitis after a single ingestion of MDMA in an Asian woman.

PubMed

Nadkarni, Girish N; Hoskote, Sumedh S; Piotrkowski, Jared; Annapureddy, Narender

2014-01-01

N-Methyl-3,4-methylenedioxyamphetamine (MDMA), also called "Ecstasy," is a commonly abused psychoactive drug among the American youth. We present the case of a 23-year-old Korean-American woman who presented with seizure, delirium, and rigidity after MDMA ingestion. She was febrile (38.7°C), tachycardic (188 beats/min), tachypneic (26 breaths/min) with a borderline blood pressure (95/43 mm Hg). Examination revealed generalized muscle rigidity, tremors, hyperreflexia, and ocular clonus, leading to the diagnosis of serotonin syndrome. Urine toxicology screen was only positive for amphetamines, consistent with the history of MDMA ingestion. Initial laboratory testing showed thrombocytopenia, further testing showed deranged prothrombin time, partial thromboplastin time, decreased fibrinogen, and elevated D-dimer, suggesting disseminated intravascular coagulation. Hepatic transaminases trended up dramatically reflecting acute hepatitis. The patient received supportive care and improved by hospital day 3. MDMA toxicity manifested as serotonin syndrome, hepatitis, and coagulopathy is exceedingly rare. MDMA is metabolized by the hepatic CYP2D6 enzyme. Certain populations, such as Koreans, Chinese, and Japanese have a high prevalence of a polymorphism that confers reduced enzyme activity. We discuss this hypothesis as a possible cause for this severe presentation in our patient after a single ingestion.

N-methyl-D-aspartate receptors and large conductance calcium-sensitive potassium channels inhibit the release of opioid peptides that induce mu-opioid receptor internalization in the rat spinal cord.

PubMed

Song, B; Marvizón, J C G

2005-01-01

Endogenous opioids in the spinal cord play an important role in nociception, but the mechanisms that control their release are poorly understood. To simultaneously detect all opioids able to activate the mu-opioid receptor, we measured mu-opioid receptor internalization in rat spinal cord slices stimulated electrically or chemically to evoke opioid release. Electrical stimulation of the dorsal horn in the presence of peptidase inhibitors produced mu-opioid receptor internalization in half of the mu-opioid receptor neurons. This internalization was rapidly abolished by N-methyl-D-aspartate (IC50=2 microM), and N-methyl-D-aspartate antagonists prevented this effect. mu-Opioid receptor internalization evoked by high K+ or veratridine was also inhibited by N-methyl-D-aspartate receptor activation. N-methyl-D-aspartate did not affect mu-opioid receptor internalization induced by exogenous endomorphins, confirming that the effect of N-methyl-D-aspartate was on opioid release. We hypothesized that this inhibition was mediated by large conductance Ca2+-sensitive K+ channels BK(Ca2+). Indeed, inhibition by N-methyl-D-aspartate was prevented by tetraethylammonium and by the selective BK(Ca2+) blockers paxilline, penitrem A and verruculogen. Paxilline did not increase mu-opioid receptor internalization in the absence of N-methyl-D-aspartate, indicating that it does not produce an increase in opioid release unrelated to the inhibition by N-methyl-d-aspartate. The BK(Ca2+) involved appears to be a subtype with slow association kinetics for iberiotoxin, which was effective only with long incubations. The BK(Ca2+) opener NS-1619 also inhibited the evoked mu-opioid receptor internalization, and iberiotoxin prevented this effect. We concluded that Ca2+ influx through N-methyl-D-aspartate receptors causes the opening of BK(Ca2+) and hyperpolarization in opioid-containing dorsal horn neurons, resulting in the inhibition of opioid release. Since mu-opioid receptors in the dorsal horn

N-METHYL-d-ASPARTATE RECEPTORS AND LARGE CONDUCTANCE CALCIUM-SENSITIVE POTASSIUM CHANNELS INHIBIT THE RELEASE OF OPIOID PEPTIDES THAT INDUCE μ-OPIOID RECEPTOR INTERNALIZATION IN THE RAT SPINAL CORD

PubMed Central

SONG, B.; MARVIZÓN, J. C. G.

2006-01-01

Endogenous opioids in the spinal cord play an important role in nociception, but the mechanisms that control their release are poorly understood. To simultaneously detect all opioids able to activate the μ-opioid receptor, we measured μ-opioid receptor internalization in rat spinal cord slices stimulated electrically or chemically to evoke opioid release. Electrical stimulation of the dorsal horn in the presence of peptidase inhibitors produced μ-opioid receptor internalization in half of the μ-opioid receptor neurons. This internalization was rapidly abolished by N-methyl-d-aspartate (IC50=2 μM), and N-methyl-d-aspartate antagonists prevented this effect. μ-Opioid receptor internalization evoked by high K+ or veratridine was also inhibited by N-methyl-d-aspartate receptor activation. N-methyl-d-aspartate did not affect μ-opioid receptor internalization induced by exogenous endomorphins, confirming that the effect of N-methyl-d-aspartate was on opioid release. We hypothesized that this inhibition was mediated by large conductance Ca2+-sensitive K+ channels BK(Ca2+). Indeed, inhibition by N-methyl-d-aspartate was prevented by tetraethylammonium and by the selective BK(Ca2+) blockers paxilline, penitrem A and verruculogen. Paxilline did not increase μ-opioid receptor internalization in the absence of N-methyl-d-aspartate, indicating that it does not produce an increase in opioid release unrelated to the inhibition by N-methyl-d-aspartate. The BK(Ca2+) involved appears to be a subtype with slow association kinetics for iberiotoxin, which was effective only with long incubations. The BK(Ca2+) opener NS-1619 also inhibited the evoked μ-opioid receptor internalization, and iberiotoxin prevented this effect. We concluded that Ca2+ influx through N-methyl-d-aspartate receptors causes the opening of BK(Ca2+) and hyperpolarization in opioid-containing dorsal horn neurons, resulting in the inhibition of opioid release. Since μ-opioid receptors in the dorsal horn

Palladium-catalyzed substitution of (coumarinyl)methyl acetates with C-, N-, and S-nucleophiles

PubMed Central

Chattopadhyay, Kalicharan; Fenster, Erik; Grenning, Alexander J

2012-01-01

Summary The palladium-catalyzed nucleophilic substitution of (coumarinyl)methyl acetates is described. The reaction proceeds though a palladium π-benzyl-like complex and allows for many different types of C-, N-, and S-nucleophiles to be regioselectively added to the biologically active coumarin motif. This new method was utilized to prepare a 128-membered library of aminated coumarins for biological screening. PMID:23019448

Clinically significant response to zolpidem in disorders of consciousness secondary to anti-N-methyl-D-aspartate receptor encephalitis in a teenager: a case report.

PubMed

Appu, Merveen; Noetzel, Michael

2014-03-01

Anti-N-methyl-d-aspartate receptor encephalitis has been associated with a prolonged neuropsychiatric phase that may last for months to years. We report the case of a 16-year-old girl who was diagnosed with anti-N-methyl-d-aspartate receptor encephalitis resulting from left ovarian mature teratoma 2 weeks after presentation with psychosis. Following tumor removal and immunotherapy, recovery from a minimally conscious state was accelerated significantly by zolpidem that was used for her sleep disturbance. Our patient was discharged home 8 weeks after admission with marked improvement in her neurological function. Zolpidem has been reported to improve arousal in disorders of consciousness but there are no previous reports of its benefit among patients with anti-N-methyl-d-aspartate receptor encephalitis. Zolpidem would be a reasonable consideration as an adjunctive treatment in anti-N-methyl-d-aspartate receptor encephalitis after tumor removal and immunotherapy to accelerate recovery and rehabilitation. Copyright © 2014 Elsevier Inc. All rights reserved.

DNA methylation on N6-adenine in mammalian embryonic stem cells

PubMed Central

Wu, Tao P.; Wang, Tao; Seetin, Matthew G.; Lai, Yongquan; Zhu, Shijia; Lin, Kaixuan; Liu, Yifei; Byrum, Stephanie D.; Mackintosh, Samuel G.; Zhong, Mei; Tackett, Alan; Wang, Guilin; Hon, Lawrence S.; Fang, Gang; Swenberg, James A.; Xiao, Andrew Z.

2016-01-01

It has been widely accepted that 5-methylcytosine is the only form of DNA methylation in mammalian genomes. Here we identify N6-methyladenine as another form of DNA modification in mouse embryonic stem cells. Alkbh1 encodes a demethylase for N6-methyladenine. An increase of N6-methyladenine levels in Alkbh1-deficient cells leads to transcriptional silencing. N6-methyladenine deposition is inversely correlated with the evolutionary age of LINE-1 transposons; its deposition is strongly enriched at young (<1.5 million years old) but not old (>6 million years old) L1 elements. The deposition of N6-methyladenine correlates with epigenetic silencing of such LINE-1 transposons, together with their neighbouring enhancers and genes, thereby resisting the gene activation signals during embryonic stem cell differentiation. As young full-length LINE-1 transposons are strongly enriched on the X chromosome, genes located on the X chromosome are also silenced. Thus, N6-methyladenine developed a new role in epigenetic silencing in mammalian evolution distinct from its role in gene activation in other organisms. Our results demonstrate that N6-methyladenine constitutes a crucial component of the epigenetic regulation repertoire in mammalian genomes. PMID:27027282

The toxicity of N-methyl-alpha-methyldopamine to freshly isolated rat hepatocytes is prevented by ascorbic acid and N-acetylcysteine.

PubMed

Carvalho, Márcia; Remião, Fernando; Milhazes, Nuno; Borges, Fernanda; Fernandes, Eduarda; Carvalho, Félix; Bastos, Maria Lourdes

2004-08-05

In the past decade, clinical evidence has increasingly shown that the liver is a target organ for 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") toxicity. The aims of the present in vitro study were: (1) to evaluate and compare the hepatotoxic effects of MDMA and one of its main metabolites, N-methyl-alpha-methyldopamine (N-Me-alpha-MeDA) and (2) to investigate the ability of antioxidants, namely ascorbic acid and N-acetyl-L-cysteine (NAC), to prevent N-Me-alpha-MeDA-induced toxic injury, using freshly isolated rat hepatocytes. Cell suspensions were incubated with MDMA or N-Me-alpha-MeDA in the final concentrations of 0.1, 0.2, 0.4, 0.8, and 1.6 mM for 3 h. To evaluate the potential protective effects of antioxidants, cells were preincubated with ascorbic acid in the final concentrations of 0.1 and 0.5 mM, or NAC in the final concentrations of 0.1 and 1 mM for 15 min before treatment with 1.6 mM N-Me-alpha-MeDA for 3 h (throughout this incubation period the cells were exposed to both compounds). The toxic effects were evaluated by measuring the cell viability, glutathione (GSH) and glutathione disulfide (GSSG), ATP, and the cellular activities of GSH peroxidase (GPX), GSSG reductase (GR), and GSH S-transferase (GST). MDMA induced a concentration- and time-dependent GSH depletion, but had a negligible effect on cell viability, ATP levels, or on the activities of GR, GPX, and GST. In contrast, N-Me-alpha-MeDA was shown to induce not only a concentration- and time-dependent depletion of GSH, but also a depletion of ATP levels accompanied by a loss in cell viability, and decreases in the antioxidant enzyme activities. For both compounds, GSH depletion was not accompanied by increases in GSSG levels, which seems to indicate GSH depletion by adduct formation. Importantly, the presence of ascorbic acid (0.5 mM) or NAC (1 mM) prevented cell death and GSH depletion induced by N-Me-alpha-MeDA. The results provide evidence that MDMA and its metabolite N

Methyl-N-methylanthranilate, a pungent compound from Citrus reticulata Blanco leaves.

PubMed

Correa, Edwin; Quiñones, Winston; Echeverri, Fernando

2016-01-01

More analgesic compounds are needed in medicine against pain since the available drugs displayed secondary effects. Natural products are a source of molecules to develop new analgesics, using the information of plants, applied against pain, with effects such as pungency, tingling, and needle, due to their possible role in the central nervous system (NCS). Citrus reticulata Blanco (Rutaceae) leaves are usually bitten to flavor the mouth and possess this type effect in lips and tongues; due to this fact the structure of the bioctive compound could be the source of other types of analgesics. The objective of this study is to determine the causal agent of the pungent effect in mandarin essential oil. Mandarin essential oil was obtained and then purified by column chromatography. Each fraction was tested and pungency was detected only in the first fraction which was pure. The compound responsible for the pungency in the essential oils of leaves from Citrus reticulata (mandarin) was purified and the structure was assigned as methyl-N-methylanthranilate, on the basis of NMR 1D and 2D and MS. This substance corresponds to another type of molecule involving an antinociceptive effect. Terpenes are compounds found in essential oils. The compound responsible for the pungency of mandarin and other citrus leaves was isolated, and surprisingly it was identified as a methyl-N-methylanthranilate. This kind of molecules with this activity could be used to discover new analgesics in human therapy against pain.

(BOSC) DOSE-RESPONSE MODELING FOR THE ASSESSMENT OF CUMULATIVE RISK DUE TO EXPOSURE TO N-METHYL CARBAMATE PRESTICIDES

EPA Science Inventory

THE US EPA'S N-METHYL CARBAMATE CUMULATIVE RISK ASSESSMENT (NMCRA) ASSESSES THE EFFECT ON ACETYLCHOLINE ESTERASE (AChE) ACTIVITY OF EXPOSURE TO 10 N-METHLY CARBAMATE (NMC)PESTICIDES THROUGH DIETARY, DRINKING WATER, AND RESIDENTIAL EXPOSURES. THESE DATA THUS INFORM, BUT DO NOT COM...

Forming Circumbinary Planets: N-body Simulations of Kepler-34

NASA Astrophysics Data System (ADS)

Lines, S.; Leinhardt, Z. M.; Paardekooper, S.; Baruteau, C.; Thebault, P.

2014-02-01

Observations of circumbinary planets orbiting very close to the central stars have shown that planet formation may occur in a very hostile environment, where the gravitational pull from the binary should be very strong on the primordial protoplanetary disk. Elevated impact velocities and orbit crossings from eccentricity oscillations are the primary contributors to high energy, potentially destructive collisions that inhibit the growth of aspiring planets. In this work, we conduct high-resolution, inter-particle gravity enabled N-body simulations to investigate the feasibility of planetesimal growth in the Kepler-34 system. We improve upon previous work by including planetesimal disk self-gravity and an extensive collision model to accurately handle inter-planetesimal interactions. We find that super-catastrophic erosion events are the dominant mechanism up to and including the orbital radius of Kepler-34(AB)b, making in situ growth unlikely. It is more plausible that Kepler-34(AB)b migrated from a region beyond 1.5 AU. Based on the conclusions that we have made for Kepler-34, it seems likely that all of the currently known circumbinary planets have also migrated significantly from their formation location with the possible exception of Kepler-47(AB)c.

Biomonitoring of exposure to N-methyl-2-pyrrolidone in workers of the automobile industry.

PubMed

Meier, Swetlana; Schindler, Birgit K; Koslitz, Stephan; Koch, Holger M; Weiss, Tobias; Käfferlein, Heiko U; Brüning, Thomas

2013-07-01

N-methyl-2-pyrrolidone (NMP) is an important organic solvent for varnishes in industry. NMP has been previously shown to be a developmental toxicant in rodents. This study reports current exposures to NMP in the spraying department of an automobile plant using biological monitoring. Two specific metabolites, 5-hydroxy-N-methyl-2-pyrrolidone (5-HNMP) and 2-hydroxy-N-methyl-succinimide (2-HMSI), were analyzed in 69 urine samples of 14 workers exposed to NMP and 9 nonexposed controls. Three different working tasks ('loading' and 'cleaning' of the sprayer system and 'wiping/packing' of the sprayed materials) and three sampling times (preshift, postshift, and preshift of the following day) were studied in exposed workers. Median exposures of 5-HNMP and 2-HMSI in postshift urine of exposed workers were 0.91 and 0.52mg g(-1) creatinine, respectively, whereas median levels in controls were below the limit of detection. Decreased levels of 5-HNMP were observed in preshift urine samples on the following day (0.39mg g(-1) creatinine) in exposed workers, while the concentration of 2-HMSI did not change (0.49mg g(-1) creatinine). Highest exposures occurred during sprayer cleaning with a maximum level of 8.31mg g(-1) creatinine of 5-HNMP in postshift urine. In contrast to 'wipers/packers', no decrease in 5-HNMP could be observed in preshift urine samples on day 2 of the 'loaders' and 'cleaners'. Overall, exposure in terms of 5-HNMP postshift and 2-HMSI preshift of the following day were well below the current biological limit values of the European Union (70 and 20mg g(-1) creatinine). Our results provide initial data on NMP exposure in the automobile industry and suggest that the analysis of 5-HNMP in preshift samples also provides essential information, particularly in situations involving direct handling of liquid NMP-containing formulations.

miR-34a inhibits the in vitro cell proliferation and migration in human esophageal cancer.

PubMed

Shi, Hui; Zhou, Shengluan; Liu, Junhua; Zhu, Jun; Xue, Jianhua; Gu, Luo; Chen, Yijiang

2016-05-01

Increasing studies demonstrate that reduced expression of miR-34a is involved in the initiation and progression of cancers, and it has been characterized as a tumor suppressor in various types of cancers. In present study, we investigated the expression and role of miR-34a in esophageal cancer. qRT-PCR assays were performed to analyze the expression of miR-34a in human esophageal cancer tissues and adjacent esophageal tissues. CCK8 assay, flow cytometry analysis and in vitro migration assays were performed to analyze the role of miR-34a in human esophageal cancer cell. MSP assay was performed to analyze the DNA methylation of the miR-34a promoter. The expression of miR-34a was down-regulated in human esophageal cancer tissues. miR-34a ectopic expression affected esophageal cancer cells survival, proliferation and capabilities of migration in vitro. p53 status was not correlated with miR-34a. Subsequently, aberrant DNA methylation of the miR-34a promoter was found in human esophageal cancer, and 5-AZA-dC inhibited DNA methylation of the miR-34a promoter. our data showed that miR-34a acted as a tumor suppressor in human esophageal cancer. Copyright © 2016. Published by Elsevier GmbH.

Effect of DNA methylation on identification of aggressive prostate cancer.

PubMed

Alumkal, Joshi J; Zhang, Zhe; Humphreys, Elizabeth B; Bennett, Christina; Mangold, Leslie A; Carducci, Michael A; Partin, Alan W; Garrett-Mayer, Elizabeth; DeMarzo, Angelo M; Herman, James G

2008-12-01

Biochemical (prostate-specific antigen) recurrence of prostate cancer after radical prostatectomy remains a major problem. Better biomarkers are needed to identify high-risk patients. DNA methylation of promoter regions leads to gene silencing in many cancers. In this study, we assessed the effect of DNA methylation on the identification of recurrent prostate cancer. We studied the methylation status of 15 pre-specified genes using methylation-specific polymerase chain reaction on tissue samples from 151 patients with localized prostate cancer and at least 5 years of follow-up after prostatectomy. On multivariate logistic regression analysis, a high Gleason score and involvement of the capsule, lymph nodes, seminal vesicles, or surgical margin were associated with an increased risk of biochemical recurrence. Methylation of CDH13 by itself (odds ratio 5.50, 95% confidence interval [CI] 1.34 to 22.67; P = 0.02) or combined with methylation of ASC (odds ratio 5.64, 95% CI 1.47 to 21.7; P = 0.01) was also associated with an increased risk of biochemical recurrence. The presence of methylation of ASC and/or CDH13 yielded a sensitivity of 72.3% (95% CI 57% to 84.4%) and negative predictive value of 79% (95% CI 66.8% to 88.3%), similar to the weighted risk of recurrence (determined from the lymph node status, seminal vesicle status, surgical margin status, and postoperative Gleason score), a powerful clinicopathologic prognostic score. However, 34% (95% CI 21% to 49%) of the patients with recurrence were identified by the methylation profile of ASC and CDH13 rather than the weighted risk of recurrence. The results of our study have shown that methylation of CDH13 alone or combined with methylation of ASC is independently associated with an increased risk of biochemical recurrence after radical prostatectomy even considering the weighted risk of recurrence score. These findings should be validated in an independent, larger cohort of patients with prostate cancer who have

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

Methyl 3-[3',4'-(methylenedioxy)phenyl]-2-methyl glycidate: an ecstasy precursor seized in Sydney, Australia.

PubMed

Collins, Michael; Heagney, Aaron; Cordaro, Frank; Odgers, David; Tarrant, Gregory; Stewart, Samantha

2007-07-01

Five 44 gallon drums labeled as glycidyl methacrylate were seized by the Australian Customs Service and the Australian Federal Police at Port Botany, Sydney, Australia, in December 2004. Each drum contained a white, semisolid substance that was initially suspected to be 3,4-methylenedioxymethylamphetamine (MDMA). Gas chromatography-mass spectroscopy (GC/MS) analysis demonstrated that the material was neither glycidyl methacrylate nor MDMA. Because intelligence sources employed by federal agents indicated that this material was in some way connected to MDMA production, suspicion fell on the various MDMA precursor chemicals. Using a number of techniques including proton nuclear magnetic resonance spectroscopy ((1)H NMR), carbon nuclear magnetic resonance spectroscopy ((13)C NMR), GC/MS, infrared spectroscopy, and total synthesis, the unknown substance was eventually identified as methyl 3-[3',4'(methylenedioxy)phenyl]-2-methyl glycidate. The substance was also subjected to a published hydrolysis and decarboxylation procedure and gave a high yield of the MDMA precursor chemical, 3,4-methylenedioxyphenyl-2-propanone, thereby establishing this material as a "precursor to a precursor."

The Submillimeter Wave Spectrum of Isotopic Methyl Cyanide

NASA Technical Reports Server (NTRS)

Pearson, J. C.; Mueller, H. S. P.

1996-01-01

The laboratory submillimeter wave rotational spectrum of the 13CH3CN, CH3C13CN, and CH3C15N isotopomers of methyl cyanide has been observed in natural abundance in the 294 to 607 GHz region. The maximum J and K values are 34 and 14, respectively. Fifteen additional CH3CN transitions up to K = 21 were also measured. The transitions of all four species are fitted to a symmetric top Hamiltonian, and the rotation and distortion constants are determined. The 14N quadrupole and spin rotation coupling constants are also calculated and presented. Suggested values for many other parameters, which could not be directly determined from the isotope spectra, are calculated from the normal species values and isotope relationships. The determined and calculated constants should predict the spectrum of the three isotopomers to well over 1 THz accurately enough for astronomical assignments.

CPT1A methylation is associated with plasma adiponectin.

PubMed

Aslibekyan, S; Do, A N; Xu, H; Li, S; Irvin, M R; Zhi, D; Tiwari, H K; Absher, D M; Shuldiner, A R; Zhang, T; Chen, W; Tanner, K; Hong, C; Mitchell, B D; Berenson, G; Arnett, D K

2017-03-01

Adiponectin, an adipose-secreted protein that has been linked to insulin sensitivity, plasma lipids, and inflammatory patterns, is an established biomarker for metabolic health. Despite clinical relevance and high heritability, the determinants of plasma adiponectin levels remain poorly understood. We conducted the first epigenome-wide cross-sectional study of adiponectin levels using methylation data on 368,051 cytosine-phosphate-guanine (CpG) sites in CD4+ T-cells from the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN, n = 991). We fit linear mixed models, adjusting for age, sex, study site, T-cell purity, and family. We have identified a positive association (regression coefficient ± SE = 0.01 ± 0.001, P = 3.4 × 10 -13 ) between plasma adiponectin levels and methylation of a CpG site in CPT1A, a key player in fatty acid metabolism. The association was replicated (n = 474, P = 0.0009) in whole blood samples from the Amish participants of the Heredity and Phenotype Intervention (HAPI) Heart Study as well as White (n = 592, P = 0.0005) but not Black (n = 243, P = 0.18) participants of the Bogalusa Heart Study (BHS). The association remained significant upon adjusting for BMI and smoking in GOLDN and HAPI but not BHS. We also identified associations between methylation loci in RNF145 and UFM1 and plasma adiponectin in GOLDN and White BHS participants, although the association was not robust to adjustment for BMI or smoking. We have identified and replicated associations between several biologically plausible loci and plasma adiponectin. These findings support the importance of epigenetic processes in metabolic traits, laying the groundwork for future translational applications. Copyright © 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All

Topographic Quantification of the Transcorneal Electrical Stimulation (TES)-Induced Protective Effects on N-Methyl-N-Nitrosourea-Treated Retinas.

PubMed

Tao, Ye; Chen, Tao; Liu, Zhong-Yu; Wang, Li-Qiang; Xu, Wei-Wei; Qin, Li-Min; Peng, Guang-Hua; Yi-Fei, Huang

2016-09-01

To quantify the transcorneal electrical stimulation (TES)-induced effects on regional photoreceptors and visual signal pathway of N-methyl-N-nitrosourea (MNU)-treated retinas via topographic measurements. N-methyl-N-nitrosourea-administered mice received TES or sham stimulations and were subsequently subjected to electroretinography (ERG), multielectrode array (MEA), and histologic and immunohistochemistry examinations. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analyses were also performed to determine the mRNA levels of Bax, Bcl-2, Calpain-2, Caspase-3, brain-derived neurotrophic factor (BDNF), and ciliary neurotrophic factor (CNTF). Amplitudes of ERG b-wave in the TES-treated mice were significantly larger than those in the sham controls (P < 0.01). Microelectrode array examination revealed that the photoreceptors in TES-treated retina were efficiently preserved (P < 0.01). Morphologic measurements showed that the central retina region was more consolidated than the other areas in the TES-treated mice. Together with the disproportionate distribution of immunostaining in retinal flat mounts, these findings indicated that different rescuing kinetics existed among regional photoreceptors. Compared with the sham controls, a significantly increased signal-to-noise ratio was also found in the TES-treated mice (TES100: 2.02 ± 1.12; TES200: 4.42 ± 1.51; sham: 0.25 ± 0.13; P < 0.01). Moreover, qRT-PCR measurements suggested that the altered expression of several apoptotic factors and neurotrophic cytokines was correlated with TES-induced protection. Regional photoreceptors in the MNU-administered retinas exhibit different sensitivities to TES. Transcorneal electrical stimulation is capable of ameliorating MNU-induced photoreceptor degeneration and rectifying abnormalities in the inner visual signal pathways.

Crystal structure of N'-[(E)-(4-chloro-phen-yl)(phen-yl)methyl-idene]-4-methyl-benzene-sulfono-hydrazide.

PubMed

Balaji, J; Prabu, S; Xavier, J J F; Srinivasan, P

2015-01-01

The title compound, C20H17ClN2O2S, was obtained by a condensation reaction between 4-chloro-benzo-phenone and tosyl hydrazide. The plane of the methyl-substituted benzene ring forms dihedral angles of 20.12 (12) and 78.43 (13)° with those of the chlorine-substituted benzene ring and the benzene ring, respectively, with the last two rings forming a dihedral angle of 67.81 (13)°. The chlorine substituent was also found to be 0.868 (2):0.132 (2) disordered over these two rings. In the crystal, mol-ecules are linked through pairs of N-H⋯O hydrogen bonds, giving centrosymmetric cyclic dimers [graph set R 2 (2)(8)], which are linked by weak C-H⋯O and C-H⋯Cl inter-actions into a chain structure which extends along the a-axis direction.

(2-{[2-(1H-Benzimidazol-2-yl-κN 3)phen­yl]imino­methyl-κN}-5-methyl­phenolato-κO)chloridozinc(II)

PubMed Central

Eltayeb, Naser Eltaher; Teoh, Siang Guan; Chantrapromma, Suchada; Fun, Hoong-Kun

2011-01-01

In the title mononuclear complex, [Zn(C21H16N3O)Cl], the ZnII ion is coordinated in a distorted tetra­hedral geometry by two benzimidazole N atoms and one phenolate O atom from the tridentate Schiff base ligand and a chloride ligand. The benzimidazole ring system forms dihedral angles of 26.68 (9) and 56.16 (9)° with the adjacent benzene ring and the methyl­phenolate group benzene ring, respectively. In the crystal, mol­ecules are linked by N—H⋯Cl hydrogen bonds into chains along [100]. Furthermore, weak C—H⋯O and C—H⋯π inter­actions, in addition to π–π inter­actions with centroid–centroid distances in the range 3.5826 (13)–3.9681 (13) Å, are also observed. PMID:22065469

Synthesis and pharmacological properties of new derivatives of 4-alkoxy-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones.

PubMed

Sladowska, Helena; Sabiniarz, Aleksandra; Sapa, Jacek; Filipek, Barbara

2009-01-01

Synthesis of 2-(2-hydroxy-3-amino)propyl derivatives of 4-alkoxy-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones (24-35) is described. The chlorides used in the above synthesis exist mainly in the cyclic forms (18, 20-23). Only chloride with benzhydryl substituent at the nitrogen atom of piperazine has the chain structure (19). Among the studied imides the most active analgesics in the "writhing" syndrome test proved to be compounds 30 and 31 (with LD50 > 2000 mg/kg) containing 4-benzylpiperidino group. Furthermore, all imides suppressed significantly spontaneous locomotor activity of mice.

Gestational intake of methyl donors and global LINE-1 DNA methylation in maternal and cord blood: prospective results from a folate-replete population.

PubMed

Boeke, Caroline E; Baccarelli, Andrea; Kleinman, Ken P; Burris, Heather H; Litonjua, Augusto A; Rifas-Shiman, Sheryl L; Tarantini, Letizia; Gillman, Matthew

2012-03-01

Maternal diet affects offspring DNA methylation in animal models, but evidence from humans is limited. We investigated the extent to which gestational intake of methyl donor nutrients affects global DNA methylation in maternal and umbilical cord blood. Among mother-infant pairs in Project Viva, a folate-replete US population, we estimated maternal intakes of vitamin B12, betaine, choline, folate, cadmium, zinc and iron periconceptionally and during the second trimester. We examined associations of these nutrients with DNA methylation, measured as %5-methyl cytosines (%5mC) in Long Interspersed Nuclear Element-1 (LINE-1), in first trimester (n = 830) and second trimester (n = 671) maternal blood and in cord blood at delivery (n = 516). Cord blood methylation was higher for male than female infants {mean [standard deviation (SD)] 84.8 [0.6] vs. 84.4 [0.7]%}. In the multivariable-adjusted model, maternal intake of methyl donor nutrients periconceptionally and during the second trimester of pregnancy was not positively associated with first trimester, second trimester or cord blood LINE-1 methylation. Periconceptional betaine intake was inversely associated with cord blood methylation [regression coefficient = -0.08% (95% confidence interval (CI): -0.14,-0.01)] but this association was attenuated after adjustment for dietary cadmium, which itself was directly associated with first trimester methylation and inversely associated with cord blood methylation. We also found an inverse association between periconceptional choline [-0.10%, 95% CI: -0.17,-0.03 for each SD (~63 mg/day)] and cord blood methylation in males only. In this folate-replete population, we did not find positive associations between intake of methyl donor nutrients during pregnancy and DNA methylation overall, but among males, higher early pregnancy intakes of choline were associated with lower cord blood methylation.

Vanillin as a modulator agent in SMART test: inhibition in the steps that precede N-methyl-N-nitrosourea-, N-ethyl-N-nitrosourea-, ethylmethanesulphonate- and bleomycin-genotoxicity.

PubMed

Sinigaglia, Marialva; Lehmann, Maurício; Baumgardt, Paula; do Amaral, Viviane Souza; Dihl, Rafael Rodrigues; Reguly, Maria Luíza; de Andrade, Heloísa Helena Rodrigues

2006-09-05

Vanillin (VA), the world's major flavoring compound used in food industry and confectionery products - that has antimutagenic and anticarcinogenic activity against a variety of mutagenic/carcinogenic agents - was tested for the interval between the formation of premutational lesion and it is finalization as a DNA lesion. The overall findings using co-treatment protocols in SMART test suggest that VA can lead to a significant protection against the general genotoxicity of ethylmethanesulphonate (EMS), N-ethyl-N-nitrosourea (ENU), N-methyl-N-nitrosourea (MNU) and bleomycin sulphate (BLEO). Considering MNU, ENU and EMS the desmutagenic activity observed could result from VA-stimulation of detoxification, via induction of glutathione S-transferase. However, the protector effect related to BLEO could be attributed to its powerful scavenger ability, which has the potential to prevent oxidative damage induced by BLEO.

Indoor residual spraying with micro-encapsulated pirimiphos-methyl (Actellic® 300CS) against malaria vectors in the Lake Victoria basin, Tanzania

PubMed Central

Manjurano, Alphaxard; Kinung’hi, Safari; Martine, Jackline; Lyimo, Eric; Kishamawe, Coleman; Ndege, Chacha; Ramsan, Mahdi M.; Chan, Adeline; Mwalimu, Charles D.; Changalucha, John; Magesa, Stephen

2017-01-01

(12.6%) were An. funestus group. Of the 236 An. gambiae s.l.identified 12.6% (n = 34) were An. gambiae s.s. and 68.6% (n = 162) were An. arabiensis. Ofthe 34 An. funestus group indentified 91.2% (n = 31) were An. parensis and 8.8% (n = 3) were An. rivulorum. The overall Plasmodium falciparum sporozoite rate was 0.7% (n = 2,098). Conclusions Pirimiphos-methyl 300 CS was found to be effective for IRS in the Lake Victoria basin,Tanzania. P-methyl 300 CShas a long residual efficacy on sprayed wall surfaces and therefore it is effective in controlling principal malaria vectors of An. gambiae s.l and An. funestus which rest on wall surfaces after and before feeding. PMID:28489935

Quantitative DNA methylation analysis of paired box gene 1 and LIM homeobox transcription factor 1 α genes in cervical cancer

PubMed Central

Xu, Ling; Xu, Jun; Hu, Zheng; Yang, Baohua; Wang, Lifeng; Lin, Xiao; Xia, Ziyin; Zhang, Zhiling; Zhu, Yunheng

2018-01-01

DNA methylation is associated with tumorigenesis and may act as a potential biomarker for detecting cervical cancer. The aim of the present study was to explore the methylation status of the paired box gene 1 (PAX1) and the LIM homeobox transcription factor 1 α (LMX1A) gene in a spectrum of cervical lesions in an Eastern Chinese population. This single-center study involved 121 patients who were divided into normal cervix (NC; n=28), low-grade squamous intraepithelial lesion (LSIL; n=32), high-grade squamous intraepithelial lesion (HSIL; n=34) and cervical squamous cell carcinoma (CSCC; n=27) groups, according to biopsy results. Following extraction and modification of the DNA, quantitative assessment of the PAX1 and LMX1A genes in exfoliated cells was performed using pyrosequencing analysis. Receiver operating characteristic (ROC) curves were generated to calculate the sensitivity and specificity of each parameter and cut-off values of the percentage of methylation reference (PMR) for differentiation diagnosis. Analysis of variance was used to identify differences among groups. The PMR of the two genes was significantly higher in the HSIL and CSCC groups compared with that in the NC and LSIL groups (P<0.001). ROC curve analysis demonstrated that the sensitivity, specificity and accuracy for detection of CSCC were 0.790, 0.837 and 0.809, respectively, using PAX1; and 0.633, 0.357 and 0.893, respectively, using LMX1A. These results indicated that quantitative PAX1 methylation demonstrates potential for cervical cancer screening, while further investigation is required to determine the potential of LMX1A methylation. PMID:29541217

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

Benchmark Dose Analysis from Multiple Datasets: The Cumulative Risk Assessment for the N-Methyl Carbamate Pesticides

EPA Science Inventory

The US EPA’s N-Methyl Carbamate (NMC) Cumulative Risk assessment was based on the effect on acetylcholine esterase (AChE) activity of exposure to 10 NMC pesticides through dietary, drinking water, and residential exposures, assuming the effects of joint exposure to NMCs is dose-...

Photophysical and Photochemical Properties of Naturally Occurring normelinonine F and Melinonine F Alkaloids and Structurally Related N(2)- and/or N(9)-methyl-β-carboline Derivatives.

PubMed

Rasse-Suriani, Federico A O; García-Einschlag, Fernando S; Rafti, Matías; Schmidt De León, Tobías; David Gara, Pedro M; Erra-Balsells, Rosa; Cabrerizo, Franco M

2018-01-01

In the present work, we have synthesized and fully characterized the photophysical and photochemical properties of a selected group of N-methyl-β-carboline derivatives (9-methyl-β-carbolines and iodine salts of 2-methyl- and 2,9-dimethyl-β-carbolinium) in aqueous solutions, in the pH range 4.0-14.5. Moreover, despite the quite extensive studies reported in the literature regarding the overall photophysical behavior of N-unsubstituted βCs, this work constitutes the first full and unambiguous characterization of anionic species of N-unsubstituted βCs (norharmane, harmane and harmine), present in aqueous solution under highly alkaline conditions (pH > 13.0). Acid dissociation constants (K a ), thermal stabilities, room temperature UV-visible absorption and fluorescence emission and excitation spectra, fluorescence quantum yields (Ф F ) and fluorescence lifetimes (τ F ), as well as quantum yields of singlet oxygen production (Ф Δ ) have been measured for all the studied compounds. Furthermore, for the first time to our knowledge, chemometric techniques (MCR-ALS and PARAFAC) were applied on these systems, providing relevant information about the equilibria and species involved. The impact of all the foregoing observations on the biological role, as well as the potential biotechnological applications of these compounds, is discussed. © 2017 The American Society of Photobiology.

A hit to lead discovery of novel N-methylated imidazolo-, pyrrolo-, and pyrazolo-pyrimidines as potent and selective mTOR inhibitors.

PubMed

Lee, Wendy; Ortwine, Daniel F; Bergeron, Philippe; Lau, Kevin; Lin, Lichuan; Malek, Shiva; Nonomiya, Jim; Pei, Zhonghua; Robarge, Kirk D; Schmidt, Stephen; Sideris, Steve; Lyssikatos, Joseph P

2013-09-15

A series of N-7-methyl-imidazolopyrimidine inhibitors of the mTOR kinase have been designed and prepared, based on the hypothesis that the N-7-methyl substituent on imidazolopyrimidine would impart selectivity for mTOR over the related PI3Kα and δ kinases. The corresponding N-Me substituted pyrrolo[3,2-d]pyrimidines and pyrazolo[4,3-d]pyrimidines also show potent mTOR inhibition with selectivity toward both PI3α and δ kinases. The most potent compound synthesized is pyrazolo[4,3-d]pyrimidine 21c. Compound 21c shows a Ki of 2 nM against mTOR inhibition, remarkable selectivity (>2900×) over PI3 kinases, and excellent potency in cell-based assays. Copyright © 2013 Elsevier Ltd. All rights reserved.

Synthesis of carbon-11-labeled 5-HT6R antagonists as new candidate PET radioligands for imaging of Alzheimer's disease.

PubMed

Wang, Xiaohong; Dong, Fugui; Miao, Caihong; Li, Wei; Wang, Min; Gao, Mingzhang; Zheng, Qi-Huang; Xu, Zhidong

2018-06-01

Carbon-11-labeled serotonin (5-hydroxytryptamine) 6 receptor (5-HT 6 R) antagonists, 1-[(2-bromophenyl)sulfonyl]-5-[ 11 C]methoxy-3-[(4-methyl-1-piperazinyl)methyl]-1H-indole (O-[ 11 C]2a) and 1-[(2-bromophenyl)sulfonyl]-5-methoxy-3-[(4-[ 11 C]methyl-1-piperazinyl)methyl]-1H-indole (N-[ 11 C]2a), 5-[ 11 C]methoxy-3-((4-methylpiperazin-1-yl)methyl)-1-(phenylsulfonyl)-1H-indole (O-[ 11 C]2b) and 5-methoxy-3-((4-[ 11 C]methylpiperazin-1-yl)methyl)-1-(phenylsulfonyl)-1H-indole (N-[ 11 C]2b), 1-((4-isopropylphenyl)sulfonyl)-5-[ 11 C]methoxy-3-((4-methylpiperazin-1-yl)methyl)-1H-indole (O-[ 11 C]2c) and 1-((4-isopropylphenyl)sulfonyl)-5-methoxy-3-((4-[ 11 C]methylpiperazin-1-yl)methyl)-1H-indole (N-[ 11 C]2c), 1-((4-fluorophenyl)sulfonyl)-5-[ 11 C]methoxy-3-((4-methylpiperazin-1-yl)methyl)-1H-indole (O-[ 11 C]2d) and 1-((4-fluorophenyl)sulfonyl)-5-methoxy-3-((4-[ 11 C]methylpiperazin-1-yl)methyl)-1H-indole (N-[ 11 C]2d), were prepared from their O- or N-desmethylated precursors with [ 11 C]CH 3 OTf through O- or N-[ 11 C]methylation and isolated by HPLC combined with SPE in 40-50% radiochemical yield, based on [ 11 C]CO 2 and decay corrected to end of bombardment (EOB). The radiochemical purity was >99%, and the molar activity (MA) at EOB was 370-740 GBq/μmol with a total synthesis time of ∼40-min from EOB. Copyright © 2018 Elsevier Ltd. All rights reserved.

40 CFR 180.451 - Tribenuron methyl; tolerances for residues.

Code of Federal Regulations, 2013 CFR

2013-07-01

... residues of the herbicide tribenuron methyl and its metabolites and degradates in or on the commodities in... defined in § 180.1(l) are established for residues of the herbicide tribenuron methyl (methyl-2-[[[[N-(4...

40 CFR 180.451 - Tribenuron methyl; tolerances for residues.

Code of Federal Regulations, 2014 CFR

2014-07-01

... residues of the herbicide tribenuron methyl and its metabolites and degradates in or on the commodities in... defined in § 180.1(l) are established for residues of the herbicide tribenuron methyl (methyl-2-[[[[N-(4...

40 CFR 180.451 - Tribenuron methyl; tolerances for residues.

Code of Federal Regulations, 2012 CFR

2012-07-01

... residues of the herbicide tribenuron methyl and its metabolites and degradates in or on the commodities in... defined in § 180.1(l) are established for residues of the herbicide tribenuron methyl (methyl-2-[[[[N-(4...

Developmental regulation of N-methyl-D-aspartate- and kainate-type glutamate receptor expression in the rat spinal cord

NASA Technical Reports Server (NTRS)

Stegenga, S. L.; Kalb, R. G.

2001-01-01

Spinal motor neurons undergo experience-dependent development during a critical period in early postnatal life. It has been suggested that the repertoire of glutamate receptor subunits differs between young and mature motor neurons and contributes to this activity-dependent development. In the present study we examined the expression patterns of N-methyl-D-aspartate- and kainate-type glutamate receptor subunits during the postnatal maturation of the spinal cord. Young motor neurons express much higher levels of the N-methyl-D-aspartate receptor subunit NR1 than do adult motor neurons. Although there are eight potential splice variants of NR1, only a subgroup is expressed by motor neurons. With respect to NR2 receptor subunits, young motor neurons express NR2A and C, while adult motor neurons express only NR2A. Young motor neurons express kainate receptor subunits GluR5, 6 and KA2 but we are unable to detect these or any other kainate receptor subunits in the adult spinal cord. Other spinal cord regions display a distinct pattern of developmental regulation of N-methyl-D-aspartate and kainate receptor subunit expression in comparison to motor neurons. Our findings indicate a precise spatio-temporal regulation of individual subunit expression in the developing spinal cord. Specific combinations of subunits in developing neurons influence their excitable properties and could participate in the emergence of adult neuronal form and function.

Plasma trimethylamine N-oxide concentration is associated with choline, phospholipids, and methyl metabolism.

PubMed

Obeid, Rima; Awwad, Hussain M; Rabagny, Yannick; Graeber, Stefan; Herrmann, Wolfgang; Geisel, Juergen

2016-03-01

Elevated plasma concentrations of the gut bacteria choline metabolite trimethylamine N-oxide (TMAO) are associated with atherosclerosis. However, the determinants of TMAO in humans require additional assessment. We examined cardiometabolic risk factors and pathways associated with TMAO concentrations in humans. A total of 283 individuals (mean ± SD age: 66.7 ± 9.0 y) were included in this observational study. Plasma concentrations of trimethylamine, TMAO, choline, lipids, phospholipids, and methyl metabolites were measured. Study participants were divided into 4 groups by median concentrations of TMAO and choline (4.36 and 9.7 μmol/L, respectively). Compared with the group with TMAO and choline concentrations that were less than the median (n = 82), the group with TMAO and choline concentrations that were at least the median (n = 83) was older and had lower high-density lipoprotein (HDL) cholesterol, phospholipids, and methylation potential, higher creatinine, betaine, S-adenosylhomocysteine (SAH), and S-adenosylmethionine (SAM), and higher percentages of men and subjects with diabetes. The difference in plasma TMAO concentrations between men and women (7.3 ± 10.0 compared with 5.4 ± 5.6 μmol/L, respectively) was NS after adjustment for age and creatinine (P = 0.455). The TMAO:trimethylamine ratio was higher in men (P < 0.001). Diabetes was associated with significantly higher plasma TMAO concentration (8.6 ± 12.2 compared with 5.4 ± 5.2 μmol/L) even after adjustments. Sex and diabetes showed an interactive effect on trimethylamine concentrations (P = 0.010) but not on TMAO concentrations (P = 0.950). Positive determinants of TMAO in a stepwise regression model that applied to the whole group were SAH, trimethylamine, choline, and female sex, whereas plasma phosphatidylcholine was a negative determinant. High TMAO and choline concentrations are associated with an advanced cardiometabolic risk profile. Diabetes is related to higher plasma TMAO

Reduced DNA methylation of FKBP5 in Cushing's syndrome.

PubMed

Resmini, Eugenia; Santos, Alicia; Aulinas, Anna; Webb, Susan M; Vives-Gilabert, Yolanda; Cox, Olivia; Wand, Gary; Lee, Richard S

2016-12-01

FKBP5 encodes a co-chaperone of HSP90 protein that regulates intracellular glucocorticoid receptor sensitivity. When it is bound to the glucocorticoid receptor complex, cortisol binds with lower affinity to glucocorticoid receptor. Cushing's syndrome is associated with memory deficits, smaller hippocampal volumes, and wide range of cognitive impairments. We aimed at evaluating blood DNA methylation of FKBP5 and its relationship with memory and hippocampal volumes in Cushing's syndrome patients. Polymorphism rs1360780 in FKBP5 has also been assessed to determine whether genetic variations can also govern CpG methylation. Thirty-two Cushing's syndrome patients and 32 matched controls underwent memory tests, 3-Tesla MRI of the brain, and DNA extraction from total leukocytes. DNA samples were bisulfite treated, PCR amplified, and pyrosequenced to assess a total of 41CpG-dinucleotides in the introns 1, 2, 5, and 7 of FKBP5. Significantly lower intronic FKBP5 DNA methylation in CS patients compared to controls was observed in ten CpG-dinucleotides. DNA methylation at these CpGs correlated with left and right HV (Intron-2-Region-2-CpG-3: LHV, r = 0.73, p = 0.02; RHV, r = 0.58, p = 0.03). Cured and active CS patients showed both lower methylation of intron 2 (92.37, 91.8, and 93.34 %, respectively, p = 0.03 for both) and of intron 7 (77.08, 73.74, and 79.71 %, respectively, p = 0.02 and p < 0.01) than controls. Twenty-two subjects had the CC genotype, 34 had the TC genotype, and eight had the TT genotype. Lower average DNA methylation in intron 7 was observed in the TT subjects compared to CC (72.5vs. 79.5 %, p = 0.02) and to TC (72.5 vs. 79.0 %, p = 0.03). Our data demonstrate, for the first time, a reduction of intronic DNA methylation of FKBP5 in CS patients.

Design and synthesis of highly potent benzodiazepine gamma-secretase inhibitors: preparation of (2S,3R)-3-(3,4-difluorophenyl)-2-(4-fluorophenyl)-4- hydroxy-N-((3S)-1-methyl-2-oxo-5- phenyl-2,3-dihydro-1H-benzo[e][1,4]-diazepin-3-yl)butyramide by use of an asymmetric Ireland-Claisen rearrangement.

PubMed

Churcher, Ian; Williams, Susie; Kerrad, Sonia; Harrison, Timothy; Castro, José L; Shearman, Mark S; Lewis, Huw D; Clarke, Earl E; Wrigley, Jonathan D J; Beher, Dirk; Tang, Yui S; Liu, Wensheng

2003-06-05

Novel benzodiazepine-containing gamma-secretase inhibitors for potential use in Alzheimer's disease have been designed that incorporate a substituted hydrocinnamide C-3 side chain. A syn combination of alpha-alkyl or aryl and beta-hydroxy or hydroxymethyl substituents was shown to give highly potent compounds. In particular, (2S,3R)-3-(3,4-difluorophenyl)-2-(4-fluorophenyl)-4-hydroxy-N-((3S)-2-oxo-5-phenyl-2,3-dihydro-1H-benzo[e][1,4]diazepin-3-yl)butyramide (34) demonstrated excellent in vitro potency (IC(50) = 0.06 nM). 34 could also be selectively methylated to give [(3)H]-28, which is of use in radioligand binding assays.

Epigenetic Regulation of KLHL34 Predictive of Pathologic Response to Preoperative Chemoradiation Therapy in Rectal Cancer Patients

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

Ha, Ye J.; Institute of Innovative Cancer Research and Asan Institute for Life Sciences, Asan Medical Center, Seoul; Kim, Chan W.

Purpose: Prediction of individual responsiveness to preoperative chemoradiation therapy (CRT) is urgently needed in patients with poorly responsive locally advanced rectal cancer (LARC). Methods and Materials: Candidate methylation genes associated with radiosensitivity were identified using a 3-step process. In the first step, genome-wide screening of methylation genes was performed in correlation with histopathologic tumor regression grade in 45 patients with LARC. In the second step, the methylation status of selected sites was analyzed by pyrosequencing in 67 LARC patients, including 24 patients analyzed in the first step. Finally, colorectal cancer cell clones with stable KLHL34 knockdown were generated and testedmore » for cellular sensitivity to radiation. Results: Genome-wide screening identified 7 hypermethylated CpG sites (DZIP1 cg24107021, DZIP1 cg26886381, ZEB1 cg04430381, DKK3 cg041006961, STL cg00991794, KLHL34 cg01828474, and ARHGAP6 cg07828380) associated with preoperative CRT responses. Radiosensitivity in patients with hypermethylated KLHL34 cg14232291 was confirmed by pyrosequencing in additional cohorts. Knockdown of KLHL34 significantly reduced colony formation (KLHL34 sh#1: 20.1%, P=.0001 and KLHL34 sh#2: 15.8%, P=.0002), increased the cytotoxicity (KLHL34 sh#1: 14.8%, P=.019 and KLHL34 sh#2: 17.9%, P=.007) in LoVo cells, and increased radiation-induced caspase-3 activity and the sub-G1 population of cells. Conclusions: The methylation status of KLHL34 cg14232291 may be a predictive candidate of sensitivity to preoperative CRT, although further validation is needed in large cohorts using various cell types.« less

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.

Synthesis of Unsymmetrical 3,4-Diaryl-3-pyrrolin-2-ones Utilizing Pyrrole Weinreb Amides

PubMed Central

Greger, Jessica G.; Yoon-Miller, Sarah J.P.; Bechtold, Nathan R.; Flewelling, Scott A.; MacDonald, Jacob P.; Downey, Catherine R.; Cohen, Eric A.; Pelkey, Erin T.

2011-01-01

A regiocontrolled synthesis of unsymmetrical 3,4-diaryl-3-pyrrolin-2-ones has been achieved in three steps from 1,2-diaryl-1-nitroethenes with pyrrole-2-carboxamides (pyrrole Weinreb amides) serving as the key linchpin intermediates. Two different methods for the preparation of the requisite nitroalkenes were investigated: (1) modified Henry reaction between arylnitromethanes and arylimines; and (2) Suzuki-Miyaura cross-coupling reaction of 2-aryl-1-bromo-1-nitroethenes with arylboronic acids. Some difficulty was encountered in the preparation of arylnitromethanes, thus leading to the exploration of a cross-coupling strategy that proved more useful. A Barton-Zard pyrrole cyclocondensation reaction between 1,2-diaryl-1-nitroethenes and N-methoxy-N-methyl-2-isocyanoacetamide gave the corresponding pyrrole Weinreb amides, which were then converted into the desired 3-pyrrolin-2-ones in two steps. Overall, this method allowed for the construction of 3,4-diaryl-3-pyrrolin-2-ones with complete regiocontrol of the substituents with respect to the lactam carbonyl. The utility of this synthetic methodology was demonstrated by the preparation of eight unsymmetrical and symmetrical 3,4-diaryl-3-pyrrolin-2-ones including the N-H lactam analog of the selective COX-II inhibitor, rofecoxib. PMID:21913662

N-AC-l-Leu-PEI-mediated miR-34a delivery improves osteogenic differentiation under orthodontic force.

PubMed

Yu, Wenwen; Zheng, Yi; Yang, Zhujun; Fei, Hongbo; Wang, Yang; Hou, Xu; Sun, Xinhua; Shen, Yuqin

2017-12-15

Rare therapeutic genes or agents are reported to control orthodontic bone remodeling. MicroRNAs have recently been associated with bone metabolism. Here, we report the in vitro and in vivo effects of miR-34a on osteogenic differentiation under orthodontic force using an N -acetyl-L-leucine-modified polyethylenimine ( N -Ac-l-Leu-PEI) carrier. N -Ac-l-Leu-PEI exhibited low cytotoxicity and high miR-34a transfection efficiency in rat bone mineral stem cells and local alveolar bone tissue. After transfection, miR-34a enhanced the osteogenic differentiation of Runx2 and ColI , Runx2 and ColI protein levels, and early osteogenesis function under orthodontic strain in vitro . MiR-34a also enhanced alveolar bone remodeling under orthodontic force in vivo , as evidenced by elevated gene and protein expression, upregulated indices of alveolar bone anabolism, and diminished tooth movement. We determined that the mechanism miR-34a in osteogenesis under orthodontic force may be associated with GSK-3β. These results suggested that miR-34a delivered by N -Ac-l-Leu-PEI could be a potential therapeutic target for orthodontic treatment.

Nonlinear pharmacokinetics of (+/-)3,4-methylenedioxymethamphetamine (MDMA) and its pharmacodynamic consequences in the rat.

PubMed

Concheiro, Marta; Baumann, Michael H; Scheidweiler, Karl B; Rothman, Richard B; Marrone, Gina F; Huestis, Marilyn A

2014-01-01

3,4-Methylenedioxymethamphetamine (MDMA) is a widely abused illicit drug that can cause severe and even fatal adverse effects. However, interest remains for its possible clinical applications in posttraumatic stress disorder and anxiety treatment. Preclinical studies to determine MDMA's safety are needed. We evaluated MDMA's pharmacokinetics and metabolism in male rats receiving 2.5, 5, and 10 mg/kg s.c. MDMA, and the associated pharmacodynamic consequences. Blood was collected via jugular catheter at 0, 0.5, 1, 2, 4, 6, 8, 16, and 24 hours, with simultaneous serotonin (5-HT) behavioral syndrome and core temperature monitoring. Plasma specimens were analyzed for MDMA and the metabolites (±)-3,4-dihydroxymethamphetamine (HHMA), (±)-4-hydroxy-3-methoxymethamphetamine (HMMA), and (±)-3,4-methylenedioxyamphetamine (MDA) by liquid chromatography-tandem mass spectrometry. After 2.5 mg/kg MDMA, mean MDMA Cmax was 164 ± 47.1 ng/ml, HHMA and HMMA were major metabolites, and <20% of MDMA was metabolized to MDA. After 5- and 10-mg/kg doses, MDMA areas under the curve (AUCs) were 3- and 10-fold greater than those after 2.5 mg/kg; HHMA and HMMA AUC values were relatively constant across doses; and MDA AUC values were greater than dose-proportional. Our data provide decisive in vivo evidence that MDMA and MDA display nonlinear accumulation via metabolic autoinhibition in the rat. Importantly, 5-HT syndrome severity correlated with MDMA concentrations (r = 0.8083; P < 0.0001) and core temperature correlated with MDA concentrations (r = 0.7595; P < 0.0001), suggesting that MDMA's behavioral and hyperthermic effects may involve distinct mechanisms. Given key similarities between MDMA pharmacokinetics in rats and humans, data from rats can be useful when provided at clinically relevant doses.

Effect of thiopental sodium on N-methyl-D-aspartate-gated currents.

PubMed

Liu, Hongliang; Dai, Tijun; Yao, Shanglong

2006-05-01

N-methyl-D-aspartate (NMDA) receptors in the prefrontal cortex (PFC) are closely related with the excitability of pyramidal neurons and PFC function. As the effect of thiopental sodium on the central nervous system may partly result from the inhibition of PFC NMDA receptors, we investigated the effect of thiopental sodium with different concentrations on NMDA-gated currents in acutely dissociated rat PFC pyramidal neurons. We sought to determine whether thiopental sodium inhibits NMDA receptor function. Three to four week old male Sprague-Dawley rats were sacrificed and the PFC was dissected. Pyramidal neurons from the PFC were prepared and standard whole-cell patch clamp recordings were performed. Escalating concentrations from 3-1000 microM NMDA were applied 100 microm from the pyramidal cells, and the concentration in the effect compartment related to 50% effect (EC50) of NMDA was determined for the ensuing experiments. One hundred microM NMDA alone (control) or NMDA with different concentrations (10-1000 microM) of thiopental sodium were applied. After the inhibitory concentration, in 50% of NMDA effect (IC50) of thiopental sodium was established this IC50 and NMDA 3-1000 microM were applied 100 microm from the pyramidal cells. The EC50 value of NMDA under the effect of IC50 thiopental sodium was determined. N-methyl-D-aspartate induced inward currents in a concentration-dependent manner, which were completely antagonized by 50 microM AP5. The maximal amplitude of NMDA-induced current was 1.15 +/- 0.27 nA. The EC50 of NMDA was 53.6 +/- 12.4 microM. The NMDA (100 microM)-gated current was inhibited by thiopental sodium in a concentration-dependent manner, and the IC50 of thiopental sodium was 33.6 +/- 6.1 microM. Under the effect of 33.6 microM thiopental sodium, the maximal amplitude of NMDA-induced current was 0.87 +/- 0.17 nA. The concentration-response curve of NMDA was shifted rightwards. The EC50 of NMDA was 128 +/- 15 microM, which was greater than that

SAPO-34 Membranes for N-2/CH4 separation: Preparation, characterization, separation performance and economic evaluation

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

Li, SG; Zong, ZW; Zhou, SJ

2015-08-01

SAPO-34 membranes were synthesized by several routes towards N-2/CH4 separation. Membrane synthesis parameters including water content in the gel, crystallization time, support pore size, and aluminum source were investigated. High performance N-2-selective membranes were obtained on 100-nm-pore alumina tubes by using Al(i-C3H7O)(3) as aluminum source with a crystallization time of 6 h. These membranes separated N-2 from CH, with N-2 permeance as high as 500 GPU with separation selectivity of 8 at 24 degrees C. for a 50/50 N-2/CH4 mixture. Nitrogen and CH, adsorption isotherms were measured on SAPO-34 crystals. The N-2 and CH, heats of adsorption were 11 andmore » 15 kJ/mol, respectively, which lead to a preferential adsorption of CE-H-4 over N-2 in the N-2/CH4 mixture. Despite this, the SAPO-34 membranes were selective for N-2 over CH4 in the mixture because N-2 diffuses much faster than CH4 and differences in diffusivity played a more critical role than the competitive adsorption. Preliminary economic evaluation indicates that the required N-2/CH4 selectivity would be 15 in order to maintain a CH4 loss below 10%. For small nitrogen-contaminated gas wells, our current SAPO-34 membranes have potential to compete with the benchmark technology cryogenic distillation for N-2 rejection. (C) 2015 Elsevier B.V. All rights reserved,« less

N-methyl-D-aspartate neurotoxicity in hippocampal slices: protection by aniracetam.

PubMed

Pizzi, M; Consolandi, O; Memo, M; Spano, P

1995-03-14

Aniracetam, a drug known to elicit cognition enhancing properties in both animals and humans, was found to counteract the neurotoxicity induced by excitatory amino acids in primary cultures of cerebellar neurons. We report here that aniracetam prevents the neurotoxic effect induced by N-methyl-D-aspartate (NMDA) in rat hippocampal slices. Time-course experiments showed that the aniracetam-induced neuroprotection does not require preincubation of the slices with the drug. Maximal effective concentration of aniracetam was 10 microM. Since the NMDA-mediated cell death in hippocampal slices is considered a valuable experimental model of ischemia, these results suggest a possible novel therapeutic application for aniracetam.

Radical-mediated enzymatic methylation: a tale of two SAMS.

PubMed

Zhang, Qi; van der Donk, Wilfred A; Liu, Wen

2012-04-17

Methylation is an essential and ubiquitous reaction that plays an important role in a wide range of biological processes. Most biological methylations use S-adenosylmethionine (SAM) as the methyl donor and proceed via an S(N)2 displacement mechanism. However, researchers have discovered an increasing number of methylations that involve radical chemistry. The enzymes known to catalyze these reactions all belong to the radical SAM superfamily. This family of enzymes utilizes a specialized [4Fe-4S] cluster for reductive cleavage of SAM to yield a highly reactive 5'-deoxyadenosyl (dAdo) radical. Radical chemistry is then imposed on a variety of organic substrates, leading to a diverse array of transformations. Until recently, researchers had not fully understood how these enzymes employ radical chemistry to mediate a methyl transfer reaction. Sequence analyses reveal that the currently identified radical SAM methyltransferases (RSMTs) can be grouped into three classes, which appear distinct in protein architecture and mechanism. Class A RSMTs mainly include the rRNA methyltransferases RlmN and Cfr from various origins. As exemplified by Escherichia coli RlmN, these proteins have a single canonical radical SAM core domain that includes an (βα)(6) partial barrel most similar to that of pyruvate formate lyase-activase. The exciting recent studies on RlmN and Cfr are beginning to provide insights into the intriguing chemistry of class A RSMTs. These enzymes utilize a methylene radical generated on a unique methylated cysteine residue. However, based on the variety of substrates used by the other classes of RSMTs, alternative mechanisms are likely to be discovered. Class B RSMTs contain a proposed N-terminal cobalamin binding domain in addition to a radical SAM domain at the C-terminus. This class of proteins methylates diverse substrates at inert sp(3) carbons, aromatic heterocycles, and phosphinates, possibly involving a cobalamin-mediated methyl transfer process. Class

Ab Initio Study of Structural and Electronic Properties of (ZnO) n "Magical" Nanoclusters n = (34, 60)

NASA Astrophysics Data System (ADS)

Bovhyra, Rostyslav; Popovych, Dmytro; Bovgyra, Oleg; Serednytski, Andrew

2017-01-01

Density functional theory studies of the structural and electronic properties of nanoclusters (ZnO) n ( n = 34, 60) in different geometric configurations were conducted. For each cluster, an optimization (relaxation) of structure geometry was performed, and the basic properties of the band structure were investigated. It was established that for the (ZnO)34 nanoclusters, the most stable are fullerene-like hollow structures that satisfy the rule of six isolated quadrangles. For the (ZnO)60 nanoclusters, different types of isomers, including hollow structures and sodalite-like structures composed from (ZnO)12 nanoclusters, were investigated. It was determined that the most energetically favorable structure was sodalite-type structure composed of seven (ZnO)12 clusters with common quadrangle edges.

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.

How does methylation suppress the electron-induced decomposition of 1-methyl-nitroimidazoles?

NASA Astrophysics Data System (ADS)

Kossoski, F.; Varella, M. T. do N.

2017-10-01

The efficient decomposition of nitroimidazoles (NIs) by low energy electrons is believed to underlie their radiosensitizing properties. Recent dissociative electron attachment (DEA) measurements showed that methylation at the N1 site unexpectedly suppresses the electron-induced reactions in 4(5)-NI. We report theoretical results that provide a clear interpretation of that astounding finding. Around 1.5 eV, DEA reactions into several fragments are initiated by a π* resonance, not considered in previous studies. The autoionization lifetime of this anion state, which limits the predissociation dynamics, is considerably shorter in the methylated species, thereby suppressing the DEA signals. On the other hand, the lifetime of the π* resonance located around 3 eV is less affected by methylation, which explains why DEA is still observed at these energies. Our results demonstrate how even a simple methylation can significantly modify the probabilities for DEA reactions, which may be significant for NI-based cancer therapy.

Geissoschizine methyl ether N-oxide, a new alkaloid with antiacetylcholinesterase activity from Uncaria rhynchophylla.

PubMed

Jiang, Wei-Wei; Su, Jia; Wu, Xing-De; He, Juan; Peng, Li-Yan; Cheng, Xiao; Zhao, Qin-Shi

2015-01-01

Geissoschizine methyl ether N-oxide, a new oxindole alkaloid, along with 14 known alkaloids, was isolated from the aerial part of Uncaria rhynchophylla. Their structures were identified by comprehensive spectral methods, including 2D NMR experiments, and confirmed by comparing with the literature data. In vitro acetylcholinesterase (AChE) inhibitory activity assay showed that the new compound exhibited anti-AChE activity with IC₅₀ value of 23.4 μM.

Structure and conformation of N-(2-methyl-5-chlorophenyl)salicylaldimine

NASA Astrophysics Data System (ADS)

Elmali, A.; Elerman, Y.

1998-02-01

N-(2-methyl-5-chlorophenyl)salicylaldimine (C 14H 12ClNO) has been studied by X-ray analysis and AM1 molecular orbital methods. It crystallises in the orthorhombic space group P2 12 12 1 with a = 7.474(1) Å, b = 12.155(1) Å, c = 13.378(1) Å, V = 1215.3(2) Å3, Z = 4, Dc = 1.343 g cm -3 and μ(Mo Kα) = 0.296 mm -1. The structure was solved by direct methods and refined to R = 0.0374 for 1689 reflections [ I > 2 σ( I)]. The title compound is photochromic and the molecule is not planar. There is a strong intramolecular hydrogen bond of distance 2.604(3) Å between the hydroxyl oxygen atom and imine nitrogen atom, the hydrogen atom essentially being bonded to the oxygen atom. Minimum energy conformations from AM1 were calculated as a function of the three torsion angles θ1(C8N1C7C6), θ2(C9C8N1C7) and θ3(N1C7C6C5), varied every 10°. The optimised geometry of the crystal structure corresponding to a non-planar conformation is the most stable conformation in all calculations.

34 CFR Appendix A to Subpart N of... - Sample Default Prevention Plan

Code of Federal Regulations, 2011 CFR

2011-07-01

... 34 Education 3 2011-07-01 2011-07-01 false Sample Default Prevention Plan A Appendix A to Subpart N of Part 668 Education Regulations of the Offices of the Department of Education (Continued) OFFICE... Default Rates Appendix A to Subpart N of Part 668—Sample Default Prevention Plan This appendix is provided...

m6A RNA Degradation Products are Catabolized by an Evolutionarily Conserved N6-methyl-AMP Deaminase in Plant and Mammalian Cells.

PubMed

Chen, Mingjia; Urs, Mounashree J; Sánchez-González, Ismael; Olayioye, Monilola A; Herde, Marco; Witte, Claus-Peter

2018-06-08

N6-methylated adenine (m6A) is the most frequent posttranscriptional modification in eukaryotic mRNA. Turnover of RNA generates N6-methylated AMP (N6-mAMP), which has an unclear metabolic fate. We show that Arabidopsis thaliana and human cells require an N6-mAMP deaminase (ADAL, renamed MAPDA) to catabolize N6-mAMP to inosine monophosphate (IMP) in vivo by hydrolytically removing the aminomethyl group. A phylogenetic, structural, and biochemical analysis revealed that many fungi partially or fully lack MAPDA, which coincides with a minor role of N6A-RNA methylation in these organisms. MAPDA likely protects RNA from m6A mis-incorporation. This is required because eukaryotic RNA polymerase can use N6-mATP as a substrate. Upon abrogation of MAPDA, root growth is slightly reduced, and the N6-methyladenosine, N6-mAMP, and N6-mATP concentrations are increased in Arabidopsis. Although this will potentially lead to m6A mis-incorporation into RNA, we show that the frequency is too low to be reliably detected in vivo. Since N6-mAMP was several fold more abundant than N6-mATP in MAPDA mutants, we speculate that additional molecular filters suppress the generation of N6-mATP. Enzyme kinetic data indicate that adenylate kinases represent such filters being highly selective for AMP versus N6-mAMP phosphorylation. We conclude that a multilayer molecular protection system is in place preventing N6-mAMP accumulation and salvage. © 2018 American Society of Plant Biologists. All rights reserved.

5-Chloro-5''-[4-(di-methyl-amino)-benzyl-idene]-4'-[4-(di-methyl-amino)-phen-yl]-1',1''-di-methyl-dispiro-[indoline-3,2'-pyrrolidine-3',3''-piperidine]-2,4''-dione.

PubMed

Farag, I S Ahmed; Girgis, Adel S; Ramadan, A A; Moustafa, A M; Tiekink, Edward R T

2014-01-01

The title compound, C34H38ClN5O2, has spiro links connecting the pyrrolidine ring and indole residue, as well as the piperidine and pyrrolidine rings. A half-chair conformation is found for the piperidine ring with the C atom connected to the spiro-C atom lying 0.738 (4) Å out of the plane of the remaining five atoms (r.m.s. deviation = 0.0407 Å). The methyl-ene C atom is the flap in the envelope conformation for the pyrrolidine ring. In the crystal, supra-molecular chains are sustained by alternating eight-membered {⋯HNCO}2 and 14-membered {⋯HC5O}2 synthons. Chains are connected into a three-dimensional network by (pyrrolidine-bound phenyl-meth-yl)C-H⋯π(pyrrolidine-bound phen-yl) edge-to-face inter-actions.

MDS and secondary AML display unique patterns and abundance of aberrant DNA methylation

PubMed Central

Figueroa, Maria E.; Skrabanek, Lucy; Li, Yushan; Jiemjit, Anchalee; Fandy, Tamer E.; Paietta, Elisabeth; Fernandez, Hugo; Tallman, Martin S.; Greally, John M.; Carraway, Hetty; Licht, Jonathan D.; Gore, Steven D.

2009-01-01

Increasing evidence shows aberrant hypermethylation of genes occurring in and potentially contributing to pathogenesis of myeloid malignancies. Several of these diseases, such as myelodysplastic syndromes (MDSs), are responsive to DNA methyltransferase inhibitors. To determine the extent of promoter hypermethylation in such tumors, we compared the distribution of DNA methylation of 14 000 promoters in MDS and secondary acute myeloid leukemia (AML) patients enrolled in a phase 1 trial of 5-azacytidine and the histone deacetylase inhibitor entinostat against de novo AML patients and normal CD34+ bone marrow cells. The MDS and secondary AML patients displayed more extensive aberrant DNA methylation involving thousands of genes than did the normal CD34+ bone marrow cells or de novo AML blasts. Aberrant methylation in MDS and secondary AML tended to affect particular chromosomal regions, occurred more frequently in Alu-poor genes, and included prominent involvement of genes involved in the WNT and MAPK signaling pathways. DNA methylation was also measured at days 15 and 29 after the first treatment cycle. DNA methylation was reversed at day 15 in a uniform manner throughout the genome, and this effect persisted through day 29, even without continuous administration of the study drugs. This trial was registered at www.clinicaltrials.gov as J0443. PMID:19652201

N(4)-[B-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan)methyl]-2'-deoxycytidine as a potential boron delivery agent with respect to glioblastoma.

PubMed

Uram, Łukasz; Nizioł, Joanna; Maj, Piotr; Sobich, Justyna; Rode, Wojciech; Ruman, Tomasz

2017-11-01

Glioblastoma multiforme (GBM) is a central nervous system tumor of grade IV, according to the WHO classification, extremely resistant to all currently used forms of therapy, including resection, radiotherapy, chemotherapy or combined therapy. Therefore, more effective treatment strategies of this tumor are needed, with boron neutron capture therapy (BNCT) being a potential solution, provided a proper cancer cells-targeted 10B delivery agent is found. In search of such an agent, toxicity and capacity to target DNA of a boronated derivative of 2'-deoxycytidine, N(4)-[B-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan)methyl]-2'-deoxycytidine (1), was tested against human tumor vs. normal cells. The present in vitro results revealed 1 to show low toxicity for human U-118 MG glioma cells (in the mM range) and even by 3-4 - fold lower against normal human fibroblasts. In accord, induction of apoptosis dependent on caspase-3 and caspase-7 was detected at high (>20mM) concentration of 1. Although demonstrated to be susceptible to phosphorylation by human deoxycytidine kinase and to undergo incorporation in cellular DNA, the boron analogue did not disturb cell proliferation when applied at non-toxic concentrations and showed low toxicity to a model metazoan organism, Caenorhabditis elegans. Thus, N(4)-[B-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan)methyl]-2'-deoxycytidine appears a promising candidate for a 10B delivery agent to be used in BNCT, with C. elegans indicated as a good model for in vivo studies. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

VDR gene methylation as a molecular adaption to light exposure: Historic, recent and genetic influences.

PubMed

Beckett, Emma L; Jones, Patrice; Veysey, Martin; Duesing, Konsta; Martin, Charlotte; Furst, John; Yates, Zoe; Jablonski, Nina G; Chaplin, George; Lucock, Mark

2017-09-10

The vitamin D receptor (VDR) is a member of the nuclear receptor family of transcription factors. We examined whether degree of VDR gene methylation acts as a molecular adaptation to light exposure. We explored this in the context of photoperiod at conception, recent UV irradiance at 305 nm, and gene-latitude effects. Eighty subjects were examined for VDR gene-CpG island methylation density. VDR gene variants were also examined by PCR-RFLP. Photoperiod at conception was significantly positively related to VDR methylation density, explaining 17% of the variance in methylation (r 2  = 0.17; P = .001). Within this model, photoperiod at conception and plasma 25(OH)D independently predicted methylation density at the VDR-CpG island. Recent UV exposure at 305 nm led to a fivefold increase in mean methylation density (P = .02). Again, UV exposure and plasma 25(OH)D independently predicted methylation density at the VDR-CpG island. In the presence of the BsmI mutant allele, methylation density was increased (P = .01), and in the presence of the TaqI or FokI mutant allele, methylation density was decreased (P = .007 and .04 respectively). Multivariate modelling suggests plasma 25(OH)D, photoperiod at conception, recent solar irradiance, and VDR genotype combine as independent predictors of methylation at the VDR-CpG island, explaining 34% of the variance in methylation (R 2  = 0.34, P < .0001). Duration of early-life light exposure and strength of recent irradiance, along with latitudinal genetic factors, influence degree of VDR gene methylation consistent with this epigenetic phenomenon being a molecular adaptation to variation in ambient light exposure. Findings contribute to our understanding of human biology. © 2017 Wiley Periodicals, Inc.

Methylation of nuclear proteins by dimethylnitrosamine and by methionine in the rat in vivo

PubMed Central

Turberville, C.; Craddock, V. M.

1971-01-01

1. The incorporation of methyl groups into histones from dimethylnitrosamine and from methionine was studied by injection of the labelled compounds, isolation of rat liver and kidney histones, and analysis of hydrolysates by column chromatography. 2. Labelled methionine gave rise to labelled ∈-N-methyl-lysine, di-∈-N-methyl-lysine and an amino acid presumed to be ω-N-methyl-arginine. 3. Administration of labelled dimethylnitrosamine gave rise to labelled S-methylcysteine, 1-methylhistidine, 3-methylhistidine and ∈-N-methyl-lysine derived from the alkylating metabolite of dimethylnitrosamine. In addition, labelled formaldehyde released by metabolism of dimethylnitrosamine leads to the formation of labelled S-adenosylmethionine, and hence to labelling of ∈-N-methyl-lysine, di-∈-N-methyl-lysine and ω-N-methylarginine by enzymic methylation. 4. The formation of ∈-N-methyl-lysine by alkylation of liver histones was confirmed by using doubly labelled dimethylnitrosamine to discriminate between direct chemical alkylation and enzymic methylation via S-adenosylmethionine. These experiments also suggested the possibility that methionine residues in the histones were alkylated to give methylmethionine sulphonium residues. 5. The extent of alkylation of liver histones was maximal at about 5h after dosing and declined between 5 and 24h. The methylated amino acids resulting from direct chemical alkylation were preferentially lost: this is ascribed to necrosis of the more highly alkylated cells. 6. Liver histones were about four times as alkylated as kidney histones; the extent of alkylation of liver histones was similar to that of liver total nuclear proteins. 7. Methyl methanesulphonate (120mg/kg) alkylated liver histones to a greater extent than did dimethylnitrosamine. Diethylnitrosamine also alkylated liver histones. 8. The results are discussed with regard to the possible effects of alkylation on histone function, and the possible role of histone alkylation in

Solubility of pioglitazone hydrochloride in binary mixtures of polyethylene glycol 400 with ethanol, propylene glycol, N-methyl-2-pyrrolidone, and water at 25 degrees C.

PubMed

Jouyban, Abolghasem; Soltanpour, Shahla

2010-09-01

The solubility of pioglitazone hydrochloride in binary mixtures of polyethylene glycol 400 with ethanol, N-methyl-2-pyrrolidone, propylene glycol, and water at 25 degrees C are reported. The generated data are fitted to the Jouyban-Acree model and the mean relative deviations are 2.6%, 1.5%, 5.8%, and 7.4%, respectively for ethanol, N-methyl-2-pyrrolidone, propylene glycol, and water.

Probes for narcotic receptor mediated phenomena. 42. Synthesis and in vitro pharmacological characterization of the N-methyl and N-phenethyl analogues of the racemic ortho-c and para-c oxide-bridged phenylmorphans

PubMed Central

Kim, Jin-Hee; Deschamps, Jeffrey R.; Rothman, Richard B.; Dersch, Christina M.; Folk, John E.; Cheng, Kejun; Jacobson, Arthur E.; Rice, Kenner C.

2011-01-01

A new synthesis of N-methyl and N-phenethyl substituted ortho-c and para-c oxide-bridged phenylmorphans, using N-benzyl- rather than N-methyl-substituted intermediates, was used and the pharmacological properties of these compounds were determined. The N-phenethyl substituted ortho-c oxide-bridged phenylmorphan (rac-(3R,6aS,11aS)-2-phenethyl-2,3,4,5,6,11a-hexahydro-1H-3,6a-methanobenzofuro[2,3-c]azocin-10-ol (12)) was found to have the highest μ-opioid receptor affinity (Ki = 1.1 nM) of all of the a- through f-oxide-bridged phenylmorphans. Functional data ([35S]GTP-γ-S) showed that the racemate 12 was more than three times more potent than naloxone as an μ-opioid antagonist. PMID:21570305

Attenuation by d-limonene of sodium chloride-enhanced gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

PubMed

Yano, H; Tatsuta, M; Iishi, H; Baba, M; Sakai, N; Uedo, N

1999-08-27

The effects of prolonged administration of d-limonene, a monocyclic monoterpene, on sodium chloride-enhanced induction of gastric carcinogenesis by N-methyl-N'-nitro-N-nitrosoguanidine, the labeling and apoptotic indices, and ornithine decarboxylase (ODC) activity of gastric cancers were investigated in Wistar rats. After 25 weeks of carcinogen treatment, rats were given chow pellets containing 10% sodium chloride and 1% limonene ad libitum. In week 52, the incidence of gastric cancers, the labeling index and ODC activity were significantly higher and the apoptotic index was significantly lower in rats given sodium chlolide than in untreated control rats. However, in rats given both sodium chloride and d-limonene, the incidence of gastric cancers, the labeling index and ODC activity were significantly lower and the apoptotic index was significantly higher than in rats given sodium chloride alone. Our findings suggest that limonene attenuates the gastric carcinogenesis enhanced by sodium chloride via increased apoptosis and decreased ODC activity in gastric cancers. Copyright 1999 Wiley-Liss, Inc.

Conformations and Barriers to Methyl Group Internal Rotation in Two Asymmetric Ethers: Propyl Methyl Ether and Butyl Methyl Ether

NASA Astrophysics Data System (ADS)

Long, B. E.; Dechirico, F.; Cooke, S. A.

2012-06-01

The conformational preferences of the O-C-C-C unit are important in many biological systems with the unit generally preferring a gauche configuration compared to an anti configuration. Butyl methyl ether and propyl methyl ether provide very simple systems for this phenomenom to manifest. Pure rotational spectra of the title molecules have been recorded using chirped pulse Fourier transform microwave spectroscopy (CP-FTMW). In the case of butyl methyl ether, only one conformer has been observed. This conformer has torsional angles of COCC = 180°, OCCC = 62° and CCCC = 180° (anti-gauche-anti) and rotational constants of A = 10259.4591(33) MHz, B = 1445.6470(13) MHz, and C = 1356.2944(14) MHz. The rotational spectrum was doubled and has been analyzed to produce an effective barrier to methyl group internal rotation of 780(35) cm-1. A prior rotational spectroscopic study on propyl methyl ether had focused only on the high energy anti-anti conformer. We have analyzed spectra from the lowest energy anti-gauche conformer and the spectroscopic constants will be presented. A summary of the differences in conformational energies and methyl group internal rotation barriers for the class of aliphatic asymmetric ethers will be presented. K. N. Houk, J. E. Eksterowicz, Y.-D. Wu, C. D. Fuglesang, D. B. Mitchell. J. Am. Chem. Soc. 115 (4170), 1993. Hiroshi Kato, Jun Nakagawa, Michiro Hayashi. J. Mol. Spectrosc. 80 (272), 1980.

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.

Interaction of amphotericin B and its low toxic derivative, N-methyl-N-D-fructosyl amphotericin B methyl ester, with fungal, mammalian and bacterial cells measured by the energy transfer method.

PubMed

Szlinder-Richert, Joanna; Cybulska, Barbara; Grzybowska, Jolanta; Bolard, Jacques; Borowski, Edward

2004-04-01

Amphotericin B (AMB) derivative, N-methyl-N-D-fructosyl amphotericin B methyl ester (MFAME) retains the broad antifungal spectrum and potency of the parent antibiotic, whereas its toxicity towards mammalian cells is reduced by about two orders of magnitude. The purpose of this work was to find out whether the differences observed in the toxicity of MFAME and native AMB are due to the differential drugs affinity to fungal and mammalian cell membranes. Comparative studies on AMB and MFAME biological activity and their affinity to fungal, mammalian and bacterial cells were performed. The interaction of AMB and MFAME with cells have been studied by fluorescence method based on the energy transfer between membrane fluorescent probe (donor) and the polyenic chromophore of the antibiotic (acceptor) simultaneously present in the cell membrane. The amount of the antibiotic bound to cells was indicated by the extent of fluorescence quenching of 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH) or 1,6-diphenyl-1,3,5-hexatriene (DPH) by polyenic chromophore of the antibiotic. The results obtained indicate that binding extent and characteristics for both antibiotics are comparable in the three types of cells studied. Dramatically lower toxicity of MFAME as compared to AMB towards mammalian cells is not related to the antibiotic-cell affinity, but rather to different consequences of these interactions for cells, reflected in membrane permeabilization. MFAME is definitely less effective than parent AMB in the permeabilizing species formation in mammalian cell membrane.

Poly[[tetra-μ-cyanido-κ8 C:N-dodeca-cyanido-κ12 C-tris­(N,N-di­methyl­formamide-κO)tris­(methanol-κO)tris­(3,4,7,8-tetra­methyl-1,10-phenanthroline-κ2 N,N′)trimanganese(II)ditungstate(V)] dihydrate

PubMed Central

Yang, Fei-Lin; Yang, Dan

2014-01-01

The asymmetric unit of the title compound, {[Mn3{W(CN)8}2(C16H16N2)3(C3H7NO)3(CH3OH)3]·2H2O}n, consists of three [Mn(N,N-di­methyl­formamide)(methanol)(3,4,7,8-tetra­methyl-1,10-phenanthroline)]2+ cations, two [W(CN)8]3− anions and two water mol­ecules. Each water mol­ecule is disordered over three sets of sites, with a refined occupancy ratio of 0.310 (9):0.275 (9):0.415 (9) for one mol­ecule and 0.335 (9):0.288 (9):0.377 (9) for the other mol­ecule. The MnII atoms exhibit a distorted octa­hedral geometry, while the WV atoms adopt a distorted square-anti­prismatic geometry. The MnII and WV atoms are linked alternatively through cyanide groups, forming a tetra­nuclear 12-atom rhombic metallacycle. Adjacent metallacycles are further connected by μ2-bridging cyanide anions, generating a 3,2-chain structure running parallel to [101]. Inter­chain π–π inter­actions are observed [centroid–centroid distances = 3.763 (3) and 3.620 (2) Å]. PMID:24860305

Rapid analysis of ecstasy and related phenethylamines in seized tablets by Raman spectroscopy.

PubMed

Bell, S E; Burns, D T; Dennis, A C; Speers, J S

2000-03-01

Raman spectroscopy with far-red excitation has been used to study seized, tableted samples of MDMA (N-methyl-3,4-methylenedioxyamphetamine) and related compounds (MDA, MDEA, MBDB, 2C-B and amphetamine sulfate), as well as pure standards of these drugs. We have found that by using far-red (785 nm) excitation the level of fluorescence background even in untreated seized samples is sufficiently low that there is little difficulty in obtaining good quality data with moderate 2 min data accumulation times. The spectra can be used to distinguish between even chemically-similar substances, such as the geometrical isomers MDEA and MBDB, and between different polymorphic/hydrated forms of the same drug. Moreover, these differences can be found even in directly recorded spectra of seized samples which have been bulked with other materials, giving a rapid and non-destructive method for drug identification. The spectra can be processed to give unambiguous identification of both drug and excipients (even when more than one compound has been used as the bulking agent) and the relative intensities of drug and excipient bands can be used for quantitative or at least semi-quantitative analysis. Finally, the simple nature of the measurements lends itself to automatic sample handling so that sample throughputs of 20 samples per hour can be achieved with no real difficulty.

Solution-phase synthesis of a hindered N-methylated tetrapeptide using Bts-protected amino acid chlorides: efficient coupling and methylation steps allow purification by extraction.

PubMed

Vedejs, E; Kongkittingam, C

2000-04-21

N-Benzothiazole-2-sulfonyl (Bts)-protected amino acid chlorides were used to prepare the hindered cyclosporin 8-11 tetrapeptide subunit 1. The synthesis was performed via 3a and the deprotected amines 5a, 13, and 19, including three repeated cycles involving N-methylation using iodomethane/potassium carbonate, deprotection of the Bts group, and N-acylation with a N-Bts-amino acid chloride such as 9b or 9c. Among three Bts cleavage methods compared (H3PO2/THF; NaBH4/EtOH; PhSH/K2CO3), the third gave somewhat higher overall yields. N-Acylation of 5a with the Bts-protected N-methylamino acid chloride 10b followed by deprotection was also highly efficient and could be used as an alternative route to 11. Each of the deprotected amines was isolated without chromatography using simple extraction methods to remove neutral byproducts. The tetrapeptide 1 was obtained in analytically pure form as the monohydrate.

Structure, phase transitions, and isotope effects in [(CH3)4N]2PuCl6

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

Wilson, Richard E.

2015-11-02

The single crystal X-ray diffraction structure of [(CH3)4N]2PuCl6 is presented for the first time, resolving long standing confusion and speculation regarding the structure of this compound in the literature. A temperature dependent study of this compound shows that the structure of [(CH3)4N]2PuCl6 undergoes no fewer than two phase transitions between 100 and 360 K. The phase of [(CH3)4N]2PuCl6 at room temperature is Fd-3c a = 26.012(3) Å. At 360 K, the structure is in space group Fm-3m with a = 13.088(1) Å. The plutonium octahedra and tetramethylammonium cations undergo a rotative displacement and the degree of rotation varies with temperature,more » giving rise to the phase transition from Fm-3m to Fd-3c as the crystal is cooled. Synthesis and structural studies of the deuterated salt [(CD3)4N]2PuCl6 suggest that there is an isotopic effect associated with this phase transition as revealed by a changing transition temperature in the deuterated versus protonated compound indicating that the donor-acceptor interactions between the tetramethylammonium cations and the hexachloroplutonate anions are driving the phase transformation.« less

(+)-3-( sup 123 I)Iodo-MK-801: Synthesis and characterization of binding to the N-methyl-D-aspartate receptor complex

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

Ransom, R.W.; Wai-si Eng; Burns, H.D.

1990-01-01

Synthetic methods have been established for preparing high specific activity (+)-3-({sup 123}I)Iodo-MK-801 in high radiochemical yield. The binding of the radiotracer to rat cortical membranes has been examine to assess its potential use as an in vivo imaging agent for the N-methyl-D-aspartate (NMDA) receptor-ion channel complex. Under the conditions of the assay, specific (+)-3-({sup 123}I)Iodo-MK-801 binding to membrane homogenates represented greater than 95% of the total binding. Several structurally distinct, noncompetitive NMDA receptor antagonists inhibited binding with potencies in accordance with their reported inhibitory activity at the receptor complex. The concentration of ({plus minus})-3-Iodo-MK-801 required to inhibit 50% of (+)-3-({supmore » 123}I)Iodo-MK-801 binding (IC{sub 50}) was 3.4 nM when using a low ionic strength assay buffer and 5.5 nM in a physiological buffer. In a thoroughly washed membrane preparation, (+)-3-({sup 123}I)Iodo-MK-801 binding was enhanced by L-glutamate and glycine at concentrations known to activate the NMDA receptor. The results indicate that (+)-3-({sup 123}I)Iodo-MK-801 specifically labels the NMDA receptor complex in rat brain membranes and the retention of high affinity under near physiological assay conditions suggests that it may be useful as a SPECT imaging agent for the receptor in vivo.« less

Nonlinear Pharmacokinetics of (±)3,4-Methylenedioxymethamphetamine (MDMA) and Its Pharmacodynamic Consequences in the Rat

PubMed Central

Concheiro, Marta; Baumann, Michael H.; Scheidweiler, Karl B.; Rothman, Richard B.; Marrone, Gina F.

2014-01-01

3,4-Methylenedioxymethamphetamine (MDMA) is a widely abused illicit drug that can cause severe and even fatal adverse effects. However, interest remains for its possible clinical applications in posttraumatic stress disorder and anxiety treatment. Preclinical studies to determine MDMA’s safety are needed. We evaluated MDMA’s pharmacokinetics and metabolism in male rats receiving 2.5, 5, and 10 mg/kg s.c. MDMA, and the associated pharmacodynamic consequences. Blood was collected via jugular catheter at 0, 0.5, 1, 2, 4, 6, 8, 16, and 24 hours, with simultaneous serotonin (5-HT) behavioral syndrome and core temperature monitoring. Plasma specimens were analyzed for MDMA and the metabolites (±)-3,4-dihydroxymethamphetamine (HHMA), (±)-4-hydroxy-3-methoxymethamphetamine (HMMA), and (±)-3,4-methylenedioxyamphetamine (MDA) by liquid chromatography–tandem mass spectrometry. After 2.5 mg/kg MDMA, mean MDMA Cmax was 164 ± 47.1 ng/ml, HHMA and HMMA were major metabolites, and <20% of MDMA was metabolized to MDA. After 5- and 10-mg/kg doses, MDMA areas under the curve (AUCs) were 3- and 10-fold greater than those after 2.5 mg/kg; HHMA and HMMA AUC values were relatively constant across doses; and MDA AUC values were greater than dose-proportional. Our data provide decisive in vivo evidence that MDMA and MDA display nonlinear accumulation via metabolic autoinhibition in the rat. Importantly, 5-HT syndrome severity correlated with MDMA concentrations (r = 0.8083; P < 0.0001) and core temperature correlated with MDA concentrations (r = 0.7595; P < 0.0001), suggesting that MDMA’s behavioral and hyperthermic effects may involve distinct mechanisms. Given key similarities between MDMA pharmacokinetics in rats and humans, data from rats can be useful when provided at clinically relevant doses. PMID:24141857

Gas-phase reactions of glycine, alanine, valine and their N-methyl derivatives with the nitrosonium ion, NO+.

PubMed

Freitas, M A; O'Hair, R A; Schmidt, J A; Tichy, S E; Plashko, B E; Williams, T D

1996-10-01

The gas-phase reactions of the nitrosonium ion, NO+ with the amino acids glycine, alanine and valine and their N-methyl derivatives were investigated under chemical ionization mass spectrometric (CIMS) conditions. Two products were observed in all cases: the formation of the iminium ion and the formation of an [M-H]+ ion. The latter product is consistent with a reaction channel involving hydride abstraction by NO+, and was confirmed by (i) examining the Ar+CI mass spectra of the same amino acids under similar source conditions and (ii) examining the unimolecular fragmentation reactions of the [M + H]+ ions of the N-nitroso-N-methyl derivatives of each of the amino acids in a tandem mass spectrometer. Further insights into the reaction of glycine with NO+ were obtained by performing ab initio calculations (at the MP2/6-31G* parallel HF/6-31G* level). These results indicate that four reactions are thermodynamically viable for glycine: (i) hydride abstraction; (ii) iminium ion formation (with concomitant loss of HONO and CO); (iii) diazonium ion formation; and (iv) diazonium ion formation followed by loss of N2. Possible reasons why reactions (iii) and (iv) are not observed are discussed, and comparisons with solution reactivity and the gas-phase reactivity of NO+ are also made.

Preventive effect of rebamipide on N-methyl-N'-nitro-N-nitrosoguanidine-induced gastric carcinogenesis in rats.

PubMed

Tsukamoto, Hironobu; Mizoshita, Tsutomu; Katano, Takahito; Hayashi, Noriyuki; Ozeki, Keiji; Ebi, Masahide; Shimura, Takaya; Mori, Yoshinori; Tanida, Satoshi; Kataoka, Hiromi; Tsukamoto, Tetsuya; Tatematsu, Masae; Joh, Takashi

2015-03-01

Chemoprevention strategies against gastric cancer (GC) need to be explored in light of the fact that stomach cancer still occurs in the absence of Helicobacter pylori (HP) infection and following HP eradication. We evaluated the effect of rebamipide on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced carcinogenesis in SD rats. Thirty-nine male rats were divided into four groups based on whether or not they were treated with rebamipide and/or MNNG: Control, Rebamipide, Control-M, and Rebamipide-M groups. From 8 weeks of age, rats in the Control-M and Rebamipide-M groups received MNNG in drinking water for 30 weeks. The Rebamipide and Rebamipide-M groups were administered 5mg/kg/day of rebamipide. At 50 weeks, cancerous lesions were not observed in either the Control or Rebamipide groups. Nine rats in the Control-M group had developed GC, while four rats in the Rebamipide-M group had developed GC. The incidence of cancer in the Rebamipide-M group was significantly less than in the Control-M group (p<0.05), with a trend toward a lower incidence of invasive carcinoma in the Rebamipide-M group. Carcinomatous invasion into the muscularis propria was not observed in the Rebamipide-M group. In conclusion, the present study demonstrates that rebamipide suppresses. MNNG-induced carcinogenesis and may also inhibit progression of cancer in rats. Copyright © 2015 Elsevier GmbH. All rights reserved.

N-methyl-N'-nitro-N-nitrosoguanidine interferes with the epidermal growth factor receptor-mediated signaling pathway.

PubMed

Gao, Zhihua; Yang, Jun; Huang, Yun; Yu, Yingnian

2005-03-01

Many environmental factors, such as ultraviolet (UV) and arsenic, can induce the clustering of cell surface receptors, including epidermal growth factor receptor (EGFR). This is accompanied by the phosphorylation of the receptors and the activation of ensuing cellular signal transduction pathways, which are implicated in the various cellular responses caused by the exposure to these factors. In this study, we have shown that N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), an alkylating agent, also induced the clustering of EGFR in human amnion FL cells, which was similar in morphology to that of epidermal growth factor treatment. However, MNNG treatment did not activate Ras, the downstream mediator in EGFR signaling pathway, as compared to EGF treatment. The autophosphorylation of tyrosine residues Y1068 and Y1173 at the intracellular domain of EGFR, which is related to Ras activation under EGF treatment, was also not observed by MNNG exposure. Interestingly, although MNNG did not affect the binding of EGF to EGFR, MNNG can interfere with EGF function. For instance, pre-incubating FL cells with MNNG inhibited the autophosphorylation of EGFR by EGF treatment, as well as the activation of Ras. In addition, the phosphorylation of Y845 on EGFR by EGF, which is mediated through c-Src or related kinases but not autophosphorylation, was also affected by MNNG. Therefore, MNNG may influence the tyrosine kinase activity as well as the phosphorylation of EGFR through its interaction with EGFR.

Studies of (±)-3,4-methylenedioxymethamphetamine (MDMA) metabolism and disposition in rats and mice: relationship to neuroprotection and neurotoxicity profile.

PubMed

Mueller, Melanie; Maldonado-Adrian, Concepcion; Yuan, Jie; McCann, Una D; Ricaurte, George A

2013-02-01

The neurotoxicity of (±)-3,4-methylenedioxymethamphetamine (MDMA; "Ecstasy") is influenced by temperature and varies according to species. The mechanisms underlying these two features of MDMA neurotoxicity are unknown, but differences in MDMA metabolism have recently been implicated in both. The present study was designed to 1) assess the effect of hypothermia on MDMA metabolism, 2) determine whether the neuroprotective effect of hypothermia is related to inhibition of MDMA metabolism, and 3) determine if different neurotoxicity profiles in mice and rats are related to differences in MDMA metabolism and/or disposition in the two species. Rats and mice received single neurotoxic oral doses of MDMA at 25°C and 4°C, and body temperature, pharmacokinetic parameters, and serotonergic and dopaminergic neuronal markers were measured. Hypothermia did not alter MDMA metabolism in rats and only modestly inhibited MDMA metabolism in mice; however, it afforded complete neuroprotection in both species. Rats and mice metabolized MDMA in a similar pattern, with 3,4-methylenedioxyamphetamine being the major metabolite, followed by 4-hydroxy-3-methoxymethamphetamine and 3,4-dihydroxymethamphetamine, respectively. Differences between MDMA pharmacokinetics in rats and mice, including faster elimination in mice, did not account for the different profile of MDMA neurotoxicity in the two species. Taken together, the results of these studies indicate that inhibition of MDMA metabolism is not responsible for the neuroprotective effect of hypothermia in rodents, and that different neurotoxicity profiles in rats and mice are not readily explained by differences in MDMA metabolism or disposition.

Studies of (±)-3,4-Methylenedioxymethamphetamine (MDMA) Metabolism and Disposition in Rats and Mice: Relationship to Neuroprotection and Neurotoxicity Profile

PubMed Central

Mueller, Melanie; Maldonado-Adrian, Concepcion; Yuan, Jie; McCann, Una D.

2013-01-01

The neurotoxicity of (±)-3,4-methylenedioxymethamphetamine (MDMA; “Ecstasy”) is influenced by temperature and varies according to species. The mechanisms underlying these two features of MDMA neurotoxicity are unknown, but differences in MDMA metabolism have recently been implicated in both. The present study was designed to 1) assess the effect of hypothermia on MDMA metabolism, 2) determine whether the neuroprotective effect of hypothermia is related to inhibition of MDMA metabolism, and 3) determine if different neurotoxicity profiles in mice and rats are related to differences in MDMA metabolism and/or disposition in the two species. Rats and mice received single neurotoxic oral doses of MDMA at 25°C and 4°C, and body temperature, pharmacokinetic parameters, and serotonergic and dopaminergic neuronal markers were measured. Hypothermia did not alter MDMA metabolism in rats and only modestly inhibited MDMA metabolism in mice; however, it afforded complete neuroprotection in both species. Rats and mice metabolized MDMA in a similar pattern, with 3,4-methylenedioxyamphetamine being the major metabolite, followed by 4-hydroxy-3-methoxymethamphetamine and 3,4-dihydroxymethamphetamine, respectively. Differences between MDMA pharmacokinetics in rats and mice, including faster elimination in mice, did not account for the different profile of MDMA neurotoxicity in the two species. Taken together, the results of these studies indicate that inhibition of MDMA metabolism is not responsible for the neuroprotective effect of hypothermia in rodents, and that different neurotoxicity profiles in rats and mice are not readily explained by differences in MDMA metabolism or disposition. PMID:23209329

New Synthesis, Structure and Analgesic Properties of Methyl 1-R-4-Methyl-2,2-Dioxo-1H-2λ⁶,1-Benzothiazine-3-Carboxylates.

PubMed

Azotla-Cruz, Liliana; Lijanova, Irina V; Ukrainets, Igor V; Likhanova, Natalya V; Olivares-Xometl, Octavio; Bereznyakova, Natalya L

2017-01-12

According to the principles of the methodology of bioisosteric replacements a series of methyl 1-R-4-methyl-2,2-dioxo-1 H -2λ⁶,1-benzothiazine-3-carboxylates has been obtained as potential analgesics. In addition, a fundamentally new strategy for the synthesis of compounds of this chemical class involving the introduction of N -alkyl substituent at the final stage in 2,1-benzothiazine nucleus already formed has been proposed. Using nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry and X-ray diffraction analysis it has been proven that in the DMSO/K₂CO₃ system the reaction of methyl 4-methyl-2,2-dioxo-1 H -2λ⁶,1-benzothiazine-3-carboxylate and alkyl halides leads to formation of N -substituted derivatives with good yields regardless of the structure of the alkylating agent. The peculiarities of NMR (¹Н and 13 С) spectra of the compounds synthesized, their mass spectrometric behavior and the spatial structure are discussed. In N -benzyl derivative the ability to form a monosolvate with methanol has been found. According to the results of the pharmacological testing conducted on the model of the thermal tail-flick it has been determined that replacement of 4-ОН-group in methyl 1-R-4-hydroxy-2,2-dioxo-1 H -2λ⁶,1-benzothiazine-3-carboxylates for the methyl group is actually bioisosteric since all methyl 1-R-4-methyl-2,2-dioxo-1 H -2λ⁶,1-benzothiazine-3-carboxylates synthesized demonstrated a statistically significant analgesic effect. The majority of the substances can inhibit the thermal pain response much more effective than piroxicam in the same dose. Under the same conditions as an analgesic the N- methyl-substituted analog exceeds not only piroxicam, but more active meloxicam as well. Therefore, it deserves in-depth biological studies on other experimental models.

Ethanol Inhibition of Constitutively Open N-Methyl-d-Aspartate Receptors

PubMed Central

Xu, Minfu; Smothers, C. Thetford; Trudell, James

2012-01-01

N-Methyl-d-aspartate (NMDA) receptors gate a slow and calcium-rich component of the postsynaptic glutamate response. Like all ionotropic glutamate receptors, NMDA subunits contain a highly conserved motif (SYTANLAAF) in the transmembrane (TM) 3 domain that is critically involved in channel gating. Mutation of an alanine in this domain (A7; underlined above) results in constitutively open receptors that show reduced sensitivity to several allosteric modulators. In this study, we examined the effects of ethanol, a substance that inhibits NMDA currents via an unknown mechanism, on tonically active NMDA receptors expressed in human embryonic kidney 293 cells. Ethanol (100 mM) inhibited currents from GluN1(A7R)/GluN2A and GluN1(A7R)/GluN2B receptors by approximately 50%, whereas those from GluN1/GluN2B(A7R) receptors were reduced by less than 10%. In cysteine-substituted GluN1 and GluN2 A7 mutants, estimated ethanol IC50 values for agonist-gated currents were 101, 117, 103, and 69 mM for GluN1(A7C)/GluN2A, GluN1(A7C)/GluN2B, GluN1/GluN2A(A7C), and GluN1/GluN2B(A7C) receptors, respectively. After exposure to the thiol-modifying reagent 2-(trimethylammonium)ethyl methanethiosulfonate (MTSET), A7C mutants showed robust agonist-independent currents and reduced sensitivity to ethanol (IC50 values of 371, 256, 715, and 958 mM, respectively, as above). In contrast, cysteine modification of the ligand-binding domain resulted in constitutively open receptors that showed robust ethanol inhibition. Ethanol inhibition of MTSET-treated GluN1(A7C) receptors was further reduced by TM3/TM4 mutations previously shown to reduce ethanol sensitivity of agonist-gated receptors. Overall, these results show that ethanol affects NMDA receptor function at a site distal from agonist binding and appears to exert greater effects via perturbation of GluN2 subunits. PMID:22005043

DNA methylation intratumor heterogeneity in localized lung adenocarcinomas.

PubMed

Quek, Kelly; Li, Jun; Estecio, Marcos; Zhang, Jiexin; Fujimoto, Junya; Roarty, Emily; Little, Latasha; Chow, Chi-Wan; Song, Xingzhi; Behrens, Carmen; Chen, Taiping; William, William N; Swisher, Stephen; Heymach, John; Wistuba, Ignacio; Zhang, Jianhua; Futreal, Andrew; Zhang, Jianjun

2017-03-28

Cancers are composed of cells with distinct molecular and phenotypic features within a given tumor, a phenomenon termed intratumor heterogeneity (ITH). Previously, we have demonstrated genomic ITH in localized lung adenocarcinomas; however, the nature of methylation ITH in lung cancers has not been well investigated. In this study, we generated methylation profiles of 48 spatially separated tumor regions from 11 localized lung adenocarcinomas and their matched normal lung tissues using Illumina Infinium Human Methylation 450K BeadChip array. We observed methylation ITH within the same tumors, but to a much less extent compared to inter-individual heterogeneity. On average, 25% of all differentially methylated probes compared to matched normal lung tissues were shared by all regions from the same tumors. This is in contrast to somatic mutations, of which approximately 77% were shared events amongst all regions of individual tumors, suggesting that while the majority of somatic mutations were early clonal events, the tumor-specific DNA methylation might be associated with later branched evolution of these 11 tumors. Furthermore, our data showed that a higher extent of DNA methylation ITH was associated with larger tumor size (average Euclidean distance of 35.64 (> 3cm, median size) versus 27.24 (<= 3cm), p = 0.014), advanced age (average Euclidean distance of 34.95 (above 65) verse 28.06 (below 65), p = 0.046) and increased risk of postsurgical recurrence (average Euclidean distance of 35.65 (relapsed patients) versus 29.03 (patients without relapsed), p = 0.039).

Holocaust Exposure Induced Intergenerational Effects on FKBP5 Methylation.

PubMed

Yehuda, Rachel; Daskalakis, Nikolaos P; Bierer, Linda M; Bader, Heather N; Klengel, Torsten; Holsboer, Florian; Binder, Elisabeth B

2016-09-01

The involvement of epigenetic mechanisms in intergenerational transmission of stress effects has been demonstrated in animals but not in humans. Cytosine methylation within the gene encoding for FK506 binding protein 5 (FKBP5) was measured in Holocaust survivors (n = 32), their adult offspring (n = 22), and demographically comparable parent (n = 8) and offspring (n = 9) control subjects, respectively. Cytosine-phosphate-guanine sites for analysis were chosen based on their spatial proximity to the intron 7 glucocorticoid response elements. Holocaust exposure had an effect on FKBP5 methylation that was observed in exposed parents as well in their offspring. These effects were observed at bin 3/site 6. Interestingly, in Holocaust survivors, methylation at this site was higher in comparison with control subjects, whereas in Holocaust offspring, methylation was lower. Methylation levels for exposed parents and their offspring were significantly correlated. In contrast to the findings at bin 3/site 6, offspring methylation at bin 2/sites 3 to 5 was associated with childhood physical and sexual abuse in interaction with an FKBP5 risk allele previously associated with vulnerability to psychological consequences of childhood adversity. The findings suggest the possibility of site specificity to environmental influences, as sites in bins 3 and 2 were differentially associated with parental trauma and the offspring's own childhood trauma, respectively. FKBP5 methylation averaged across the three bins examined was associated with wake-up cortisol levels, indicating functional relevance of the methylation measures. This is the first demonstration of an association of preconception parental trauma with epigenetic alterations that is evident in both exposed parent and offspring, providing potential insight into how severe psychophysiological trauma can have intergenerational effects. Published by Elsevier Inc.

RNA N6-adenosine methylation (m6A) steers epitranscriptomic control of herpesvirus replication

PubMed Central

Ye, Fengchun

2017-01-01

Latency is a hallmark of all herpesviruses, during which the viral genomes are silenced through DNA methylation and suppressive histone modifications. When latent herpesviruses reactivate to undergo productive lytic replication, the suppressive epigenetic marks are replaced with active ones to allow for transcription of viral genes. Interestingly, by using Kaposi’s sarcoma-associated herpesvirus (KSHV) as a model, we recently demonstrated that the newly transcribed viral RNAs are also subjected to post-transcriptional N6-adenosine methylation (m6A). Blockade of this post-transcriptional event abolishes viral protein expression and halts virion production. We found that m6A modification controls RNA splicing, stability, and protein translation to regulate viral lytic gene expression and replication. Thus, our finding for the first time reveals a critical role of this epitranscriptomic mechanism in the control of herpesviral replication, which shall shed lights on development of novel strategies for the control of herpesviral infection. PMID:29082271

Crystal structure of catena-poly[N,N,N′,N′-tetra­methyl­guanidinium [(chlorido­cadmate)-di-μ-chlorido

PubMed Central

Ndiaye, Mamadou; Samb, Abdoulaye; Diop, Libasse; Maris, Thierry

2016-01-01

In the structure of the title salt, {(C5H14N3)[CdCl3]}n, the CdII atom of the complex anion is five-coordinated by one terminal and four bridging Cl atoms. The corresponding coordination polyhedron is a distorted trigonal bipyramid, with Cd—Cl distances in the range 2.4829 (4)–2.6402 (4) Å. The bipyramids are condensed into a polyanionic zigzag chain extending parallel to [101]. The tetra­methyl­guanidinium cations are situated between the polyanionic chains and are linked to them through N—H⋯Cl hydrogen bonds, forming a layered network parallel to (010). PMID:26870572

Self-reported smoking, serum cotinine, and blood DNA methylation.

PubMed

Zhang, Yan; Florath, Ines; Saum, Kai-Uwe; Brenner, Hermann

2016-04-01

Epigenome-wide profiling of DNA methylation pattern with respect to tobacco smoking has given rise to a new measure of smoking exposure. We investigated the relationships of methylation markers with both cotinine, an established marker of internal smoking exposure, and self-reported smoking. Blood DNA methylation levels across the genome and serum cotinine were measured in 1000 older adults aged 50-75 years. Epigenome-wide scans were performed to identify methylation markers associated with cotinine. The inter-dose-response relationships between the number of cigarettes smoked per day, cotinine concentration, and DNA methylation were modeled by restricted cubic spline regression. Of 61 CpGs that passed the genome-wide significance threshold (p<1.13×10(-7)), 40 CpGs in 25 chromosomal regions were successfully replicated, showing 0.2-3% demethylation per 10ng/ml increases in cotinine. The strongest associations were observed for several loci at AHRR, F2RL3, 2q37.1, 6p21.33, and GFI1 that were previously identified to be related to self-reported smoking. One locus at RAB34 was newly discovered. Both cotinine and methylation markers exhibited non-linear relationships with the number of cigarettes smoked per day, where the highest rates of increase in cotinine and decreases in methylation were observed at low smoking intensity (1-15 cigarettes/day) and plateaued at high smoking intensity (>15-20 cigarettes/day). A clear linear relationship was observed between cotinine concentration and methylation level. Both cotinine and methylation markers showed similar accuracy in distinguishing current from never smoker, but only methylation markers distinguished former from never smoker with high accuracy. Our study corroborates and expands the list of smoking-associated DNA methylation markers. Methylation levels were linearly related to cotinine concentration and provided accurate measures for both current and past smoking exposure. Copyright © 2016 Elsevier Inc. All rights

Cytotoxic effects of psychotropic benzofuran derivatives, N-methyl-5-(2-aminopropyl)benzofuran and its N-demethylated derivative, on isolated rat hepatocytes.

PubMed

Nakagawa, Yoshio; Suzuki, Toshinari; Tada, Yukie; Inomata, Akiko

2017-03-01

The novel psychoactive compounds derived from amphetamine have been illegally abused as recreational drugs, some of which are known to be hepatotoxic in humans and experimental animals. The cytotoxic effects and mechanisms of 5-(2-aminopropyl)benzofuran (5-APB) and N-methyl-5-(2-aminopropyl)benzofuran (5-MAPB), both of which are benzofuran analogues of amphetamine, and 3,4-methylenedioxy-N-methamphetamine (MDMA) were studied in freshly isolated rat hepatocytes. 5-MAPB caused not only concentration-dependent (0-4.0 mm) and time-dependent (0-3 h) cell death accompanied by the depletion of cellular ATP and reduced glutathione and protein thiol levels, but also accumulation of oxidized glutathione. Of the other analogues examined at a concentration of 4 mm, 5-MAPB/5-APB-induced cytotoxicity with the production of reactive oxygen species and loss of mitochondrial membrane potential was greater than that induced by MDMA. In isolated rat liver mitochondria, the benzofurans resulted in a greater increase in the rate of state 4 oxygen consumption than did MDMA, with a decrease in the rate of state 3 oxygen consumption. Furthermore, the benzofurans caused more of a rapid mitochondrial swelling dependent on the mitochondrial permeability transition than MDMA. 5-MAPB at a weakly toxic level (1 mm) was metabolized slowly: levels of 5-MAPB and 5-APB were approximately 0.9 mm and 50 μm, respectively, after 3 h incubation. Taken collectively, these results indicate that mitochondria are target organelles for the benzofuran analogues and MDMA, which elicit cytotoxicity through mitochondrial failure, and the onset of cytotoxicity may depend on the initial and/or residual concentrations of 5-MAPB rather than on those of its metabolite 5-APB. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

N-linked glycosylation of cortical N-methyl-D-aspartate and kainate receptor subunits in schizophrenia.

PubMed

Tucholski, Janusz; Simmons, Micah S; Pinner, Anita L; McMillan, Laurence D; Haroutunian, Vahram; Meador-Woodruff, James H

2013-08-21

Dysfunctional glutamate neurotransmission has been implicated in the pathophysiology of schizophrenia. Abnormal expressions in schizophrenia of ionotropic glutamate receptors (iGluRs) and the proteins that regulate their trafficking have been found to be region and subunit specific in brain, suggesting that abnormal trafficking of iGluRs may contribute toward altered glutamatergic neurotransmission. The post-translational modification N-glycosylation of iGluR subunits can be used as a proxy for their intracellular localization. Receptor complexes assemble in the lumen of the endoplasmic reticulum, where N-glycosylation begins with the addition of N-linked oligomannose glycans, and is subsequently trimmed and replaced by more elaborate glycans while trafficking through the Golgi apparatus. Previously, we found abnormalities in N-glycosylation of the GluR2 AMPA receptor subunit in schizophrenia. Here, we investigated N-glycosylation of N-methyl-D-aspartate and kainate (KA) receptor subunits in the dorsolateral prefrontal cortex from patients with schizophrenia and a comparison group. We used enzymatic deglycosylation with two glycosidases: endoglycosidase H (Endo H), which removes immature high mannose-containing sugars, and peptide-N-glycosidase F (PNGase F), which removes all N-linked sugars. The NR1, NR2A, NR2B, GluR6, and KA2 subunits were all sensitive to treatment with Endo H and PNGase F. The GluR6 KA receptor subunit was significantly more sensitive to Endo H-mediated deglycosylation in schizophrenia, suggesting a larger molecular mass of N-linked high mannose and/or hybrid sugars on GluR6. This finding, taken with our previous work, suggests that a cellular mechanism underlying abnormal glutamate neurotransmission in schizophrenia may involve abnormal trafficking of both AMPA and KA receptors.

Analysis of the expression level and methylation of tumor protein p53, phosphatase and tensin homolog and mutS homolog 2 in N-methyl-N-nitrosourea-induced thymic lymphoma in C57BL/6 mice.

PubMed

Huo, Xueyun; Li, Zhenkun; Zhang, Shuangyue; Li, Changlong; Guo, Meng; Lu, Jing; Lv, Jianyi; Du, Xiaoyan; Chen, Zhenwen

2017-10-01

Tumorigenesis is often caused by somatic mutation or epigenetic changes in genes that regulate aspects of cell death, proliferation and survival. Although the functions of multiple tumor suppressor genes have been well studied in isolation, how these genes cooperate during the progression of a single tumor remains unclear in numerous cases. The present study used N-methyl-N-nitrosourea (MNU), one of the most potent mutagenic nitrosourea compounds, to induce thymic lymphoma in C57BL/6J mice. Subsequently, the protein expression levels of phosphatase and tensin homolog (PTEN), transformation protein 53 and mutS homolog 2 (MSH2) were evaluated concomitantly in the thymus, liver, kidney and spleen of MNU-treated mice by western blotting. To determine whether changes in expression level were due to aberrant epigenetic regulation, the present study further examined the methylation status of each gene by MassARRAY analysis. During the tumorigenesis process of an MNU-induced single thymic lymphoma, the expression level of PTEN was revealed to be reduced in thymic lymphoma samples but not in normal or non-tumor thymus tissue samples. Furthermore, a marked reduction of P53 expression levels were demonstrated in thymic lymphomas and spleens with a metastatic tumor. Conversely, MSH2 upregulation was identified only in liver, kidney, and spleen samples that were infiltrated by thymic lymphoma cells. Furthermore, the present study revealed that a number of 5'-C-phosphate-G-3' sites located in the promoter of aberrantly expressed genes had significantly altered methylation statuses. These results improve the understanding of the course of mutagen-induced cancer, and highlight that epigenetic regulation may serve an important function in cancer.

Nanoliposomes for encapsulation and delivery of the potential antitumoral methyl 6-methoxy-3-(4-methoxyphenyl)-1 H-indole-2-carboxylate

NASA Astrophysics Data System (ADS)

Abreu, Ana S.; Castanheira, Elisabete Ms; Queiroz, Maria-João Rp; Ferreira, Paula Mt; Vale-Silva, Luís A.; Pinto, Eugénia

2011-08-01

A potential antitumoral fluorescent indole derivative, methyl 6-methoxy-3-(4-methoxyphenyl)-1 H-indole-2-carboxylate, was evaluated for the in vitro cell growth inhibition on three human tumor cell lines, MCF-7 (breast adenocarcinoma), A375-C5 (melanoma), and NCI-H460 (non-small cell lung cancer), after a continuous exposure of 48 h, exhibiting very low GI50 values for all the cell lines tested (0.25 to 0.33 μM). This compound was encapsulated in different nanosized liposome formulations, containing egg lecithin (Egg-PC), dipalmitoyl phosphatidylcholine (DPPC), dipalmitoyl phosphatidylglycerol (DPPG), DSPC, cholesterol, dihexadecyl phosphate, and DSPE-PEG. Dynamic light scattering measurements showed that nanoliposomes with the encapsulated compound are generally monodisperse and with hydrodynamic diameters lower than 120 nm, good stability and zeta potential values lower than -18 mV. Dialysis experiments allowed to monitor compound diffusion through the lipid membrane, from DPPC/DPPG donor liposomes to NBD-labelled lipid/DPPC/DPPG acceptor liposomes.

Dopaminergic neurotoxicity of S-ethyl N,N-dipropylthiocarbamate (EPTC), molinate, and S-methyl-N,N-diethylthiocarbamate (MeDETC) in Caenorhabditis elegans

PubMed Central

Caito, Samuel W.; Valentine, William M.; Aschner, Michael

2013-01-01

Epidemiological studies corroborate a correlation between pesticide use and Parkinson’s disease (PD). Thiocarbamate and dithiocarbamate pesticides are widely used and produce neurotoxicity in the peripheral nervous system. Recent evidence from rodent studies suggests that these compounds also cause dopaminergic (DAergic) dysfunction and altered protein processing, two hallmarks of PD. However, DAergic neurotoxicity has yet to be documented. We assessed DAergic dysfunction in Caenorhabditis elegans (C. elegans) to investigate the ability of thiocarbamate pesticides to induce DAergic neurodegeneration. Acute treatment with either S-ethyl N,N-dipropylthiocarbamate (EPTC), molinate, or a common reactive intermediate of dithiocarbamate and thiocarbamate metabolism, S-methyl-N,N-diethylthiocarbamate (MeDETC), to gradual loss of DAergic cell morphology and structure over the course of 6 days in worms expressing green fluorescent protein (GFP) under a DAergic cell specific promoter. HPLC analysis revealed decreased DA content in the worms immediately following exposure to MeDETC, EPTC, and molinate. Additionally, worms treated with the three test compounds showed a drastic loss of DAergic-dependent behavior over a time course similar to changes in DAergic cell morphology. Alterations in the DAergic system were specific, as loss of cell structure and neurotransmitter content was not observed in cholinergic, glutamatergic, or GABAergic systems. Overall, our data suggest that thiocarbamate pesticides promote neurodegeneration and DAergic cell dysfunction in C. elegans, and may be an environmental risk factor for PD. PMID:23786526

Identification of methylated genes associated with aggressive bladder cancer.

PubMed

Marsit, Carmen J; Houseman, E Andres; Christensen, Brock C; Gagne, Luc; Wrensch, Margaret R; Nelson, Heather H; Wiemels, Joseph; Zheng, Shichun; Wiencke, John K; Andrew, Angeline S; Schned, Alan R; Karagas, Margaret R; Kelsey, Karl T

2010-08-23

Approximately 500,000 individuals diagnosed with bladder cancer in the U.S. require routine cystoscopic follow-up to monitor for disease recurrences or progression, resulting in over $2 billion in annual expenditures. Identification of new diagnostic and monitoring strategies are clearly needed, and markers related to DNA methylation alterations hold great promise due to their stability, objective measurement, and known associations with the disease and with its clinical features. To identify novel epigenetic markers of aggressive bladder cancer, we utilized a high-throughput DNA methylation bead-array in two distinct population-based series of incident bladder cancer (n = 73 and n = 264, respectively). We then validated the association between methylation of these candidate loci with tumor grade in a third population (n = 245) through bisulfite pyrosequencing of candidate loci. Array based analyses identified 5 loci for further confirmation with bisulfite pyrosequencing. We identified and confirmed that increased promoter methylation of HOXB2 is significantly and independently associated with invasive bladder cancer and methylation of HOXB2, KRT13 and FRZB together significantly predict high-grade non-invasive disease. Methylation of these genes may be useful as clinical markers of the disease and may point to genes and pathways worthy of additional examination as novel targets for therapeutic treatment.

Simultaneous determination of amphetamine-type stimulants and cannabinoids in fingernails by gas chromatography-mass spectrometry.

PubMed

Kim, Jin Young; Cheong, Jae Chul; Kim, Min Kyoung; Lee, Jae Il; In, Moon Kyo

2008-06-01

A gas chromatography-mass spectrometric (GC-MS) method was developed and validated for the simultaneous detection and quantification of four amphetamine-type stimulants (amphetamine (AP), methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA)) and two cannabinoids (Delta9-tetrahydrocannabinol (Delta9-THC) and 11-nor-Delta9-tetrahydrocannabinol-9-carboxylic acid (THCCOOH)) in fingernails. Fingernail clippings (30 mg) were washed with distilled water and methanol, and then incubated in 1.0 M sodium hydroxide at 95 degrees C for 30 min. The compounds of interest were isolated by liquid-liquid extraction followed by derivatization with N-methyl-N-trimethylsilyltrifluoroacetamide (MSTFA) at 70 degrees C for 15 min. The derivatized compounds were analyzed by GC-MS in the selective ion monitoring (SIM) mode. The linear ranges were 0.1-15.0 ng/mg for AP, 0.2-15.0 ng/mg for MDA, Delta9-THC and THCCOOH, and 0.2-30.0 ng/mg for MA and MDMA, with good correlation coefficients (r2 > 0.9991). The intra-day, inter-day, and inter-person precisions were within 10.6%, 6.3%, and 5.3%, respectively. The intra-day, inter-day and inter-person accuracies were between -6.1 and 5.0%, -6.2 and 5.7%, and -6.4 and 5.6%, respectively. The limits of detection (LODs) and quantification (LOQs) for each compound were lower than 0.056 and 0.2 ng/mg, respectively. The recoveries were in the range of 74.0-94.8%. Positive GC-MS results were obtained from specimens of nine suspected MA or cannabis abusers. The concentration ranges of MA, AP, and THCCOOH were 0.10-1.41, 0.12-2.64, and 0.20 ng/mg, respectively. Based on these results, the method proved to be effective for the simultaneous qualification and quantification of amphetamine-type stimulants and cannabinoids in fingernails.

Maternal melatonin or N-acetylcysteine therapy regulates hydrogen sulfide-generating pathway and renal transcriptome to prevent prenatal NG-Nitro-L-arginine-methyl ester (L-NAME)-induced fetal programming of hypertension in adult male offspring.

PubMed

Tain, You-Lin; Lee, Chien-Te; Chan, Julie Y H; Hsu, Chien-Ning

2016-11-01

Pregnancy is a critical time for fetal programming of hypertension. Nitric oxide deficiency during pregnancy causes hypertension in adult offspring. We examined whether maternal melatonin or N-acetylcysteine therapy can prevent N G -nitro-L-arginine-methyl ester-induced fetal programming of hypertension in adult offspring. Next, we aimed to identify potential gatekeeper pathways that contribute to N G -nitro-L-arginine-methyl ester -induced programmed hypertension using the next generation RNA sequencing technology. Pregnant Sprague-Dawley rats were assigned to 4 groups: control, N G -nitro-L-arginine-methyl ester, N G -nitro-L-arginine-methyl ester +melatonin, and N G -nitro-L-arginine-methyl ester+N-acetylcysteine. Pregnant rats received N G -nitro-L-arginine-methyl ester administration at 60 mg/kg/d subcutaneously during pregnancy alone, with additional 0.01% melatonin in drinking water, or with additional 1% N-acetylcysteine in drinking water during the entire pregnancy and lactation. Male offspring (n=8/group) were killed at 12 weeks of age. N G -nitro-L-arginine-methyl ester exposure during pregnancy induced programmed hypertension in adult male offspring, which was prevented by maternal melatonin or N-acetylcysteine therapy. Protective effects of melatonin and N-acetylcysteine against N G -nitro-L-arginine-methyl ester-induced programmed hypertension were associated with an increase in hydrogen sulfide-generating enzymes and hydrogen sulfide synthesis in the kidneys. Nitric oxide inhibition by N G -nitro-L-arginine-methyl ester in pregnancy caused >2000 renal transcripts to be modified during nephrogenesis stage in 1-day-old offspring kidney. Among them, genes belong to the renin-angiotensin system, and arachidonic acid metabolism pathways were potentially involved in the N G -nitro-L-arginine-methyl ester-induced programmed hypertension. However, melatonin and N-acetylcysteine reprogrammed the renin-angiotensin system and arachidonic acid pathway

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

Evaluation of N-[(11)C]methyl-AMD3465 as a PET tracer for imaging of CXCR4 receptor expression in a C6 glioma tumor model.

PubMed

Hartimath, S V; van Waarde, A; Dierckx, R A J O; de Vries, E F J

2014-11-03

The chemokine receptor CXCR4 and its ligand CXCL12 play an important role in tumor progression and metastasis. CXCR4 receptors are expressed by many cancer types and provide a potential target for treatment. Noninvasive detection of CXCR4 may aid diagnosis and improve therapy selection. It has been demonstrated in preclinical studies that positron emission tomography (PET) with a radiolabeled small molecule could enable noninvasive monitoring of CXCR4 expression. Here, we prepared N-[(11)C]methyl-AMD3465 as a new PET tracer for CXCR4. N-[(11)C]Methyl-AMD3465 was readily prepared by N-methylation with [(11)C]CH3OTf. The tracer was obtained in a 60 ± 2% yield (decay corrected), the purity of the tracer was >99%, and specific activity was 47 ± 14 GBq/μmol. Tracer stability was tested in vitro using liver microsomes and rat plasma; excellent stability was observed. The tracer was evaluated in rat C6 glioma and human PC-3 cell lines. In vitro cellular uptake of N-[(11)C]methyl-AMD3465 was receptor mediated. The effect of transition metal ions (Cu(2+), Ni(2+), and Zn(2+)) on cellular binding was examined in C6 cells, and the presence of these ions increased the cellular binding of the tracer 9-, 7-, and 3-fold, respectively. Ex vivo biodistribution and PET imaging of N-[(11)C]methyl-AMD3465 were performed in rats with C6 tumor xenografts. Both PET and biodistribution studies demonstrated specific accumulation of the tracer in the tumor (SUV 0.6 ± 0.2) and other CXCR4 expressing organs, such as lymph node (1.5 ± 0.2), liver (8.9 ± 1.0), bone marrow (1.0 ± 0.3), and spleen (1.0 ± 0.1). Tumor uptake was significantly reduced (66%, p < 0.01) after pretreatment with Plerixafor (AMD3100). Biodistribution data indicates a tumor-to-muscle ratio of 7.85 and tumor-to-plasma ratio of 1.14, at 60 min after tracer injection. Our data demonstrated that N-[(11)C]methyl-AMD3465 is capable of detecting physiologic CXCR4 expression in tumors and other CXCR4 expressing tissues

Identification of ω-N-Methyl-4-hydroxytryptamine (Norpsilocin) as a Psilocybe Natural Product.

PubMed

Lenz, Claudius; Wick, Jonas; Hoffmeister, Dirk

2017-10-27

We report the identification of ω-N-methyl-4-hydroxytryptamine (norpsilocin, 1) from the carpophores of the hallucinogenic mushroom Psilocybe cubensis. The structure was elucidated by 1D and 2D NMR spectroscopy and high-resolution mass spectrometry. Norpsilocin has not previously been reported as a natural product. It likely represents the actual psychotropic agent liberated from its 4-phosphate ester derivative, the known natural product baeocystin. We further present a simple and artifact-free extraction method that prevents dephosphorylation and therefore helps reflect the naturally occurring metabolic profile of Psilocybe mushrooms in subsequent analyses.

Promoter methylation assay of SASH1 gene in hepatocellular carcinoma.

PubMed

Peng, Liu; Wei, He; Liren, Li

2014-01-01

To analyse the relationship between the expression of SASH1 and its methylation level in human hepatocellular carcinoma. Expression levels of SASH1 were examined with real-time PCR (RT-PCR) in tissues and cells, and methylation analysis was performed with MassArray. The expression levels of SASH1 were strongly reduced in liver cancer tissues compared with adjacent normal tissues. Quantitative methylation analysis by MassArray revealed different CpG sites in SASH1 promoter shared similar methylation pattern between liver cancer tissues and adjacent normal tissues and the CpG sites of significant difference in methylation level were found as follows: CpG_3, CpG_17, CpG_21.22, CpG_25, CpG_26.27, CpG_28, CpG_34.35.36 and CpG_51.52. Moreover, 5-aza-2'-deoxycytidine treatment of Hep-G2 cell line caused significant elevation of SASH1 mRNA. Based on these data, we propose that increase of DNA methylation degree in the promoter region of SASH1 gene, particularly CpG_26.27 sites, possibly repressed SASH1 expression in liver cancer.

[Inactivation of PMS2 gene by promoter methylation in nasopharyngeal carcinoma].

PubMed

Ni, H F; Jiang, B; Zhou, Z; Li, Y; Yuan, X Y; Cao, X L; Huang, G W

2016-11-23

Objective: To investigate the inactivation of PMS2 gene mediated by promoter methylation and its regulatory mechanism in nasopharyngeal carcinoma (NPC). Methods: Fifty-four NPC tissues, 16 normal nasopharyngeal epithelia (NNE), 5 NPC cell lines (CNE1, CNE2, TWO3, HNE1 and HONE1) and 1 normal nasopharyngeal epithelial cell line (NP69) were collected.Methylation-specific PCR (MSP) was used to detect the PMS2 promoter methylation, semi-quantitative reverse transcription PCR (qRT-PCR) was applied to determine its mRNA expression, and immunohistochemistry (IHC) was used to detect the protein expression of PMS2. The expressions of PMS2 mRNA in CNE1 and CNE2 cells before and after treated with methyltransferase inhibitor 5-aza-2-deoxycytidine were analyzed by qRT-PCR. The impact of methylation and demethylation on the mRNA expression of PMS2, and the association of mRNA and protein expression of PMS2 with clinicopathological features of nasopharyngeal cancer were analyzed. Results: Methylation of PMS2 gene was detected in all of the five NPC cell lines, but not in normal nasopharyngeal epithelial NP69 cells. The methylation rate of PMS2 gene in NPC tissues was 63% (34/54), significantly higher than that of the normal nasopharyngeal epithelia (0/16, P <0.001). The expression levels of PMS2 mRNA and protein were significantly down-regulated in the 54 NPC tissues when compared with those in the 16 NNE tissues ( P <0.001), and were also significantly lower in the 34 methylated NPC tissues than those in the 20 unmethylated NPC tissues ( P <0.001). After treatment with 5-aza-2-deoxycytidine, the expression of PMS2 mRNA was restored in the CNE1 and CNE2 cells.However, the expressions of PMS2 mRNA and protein were not significantly correlated with patients' age, gender, TNM stage, histopathologic type or lymph node metastasis ( P >0.05 for all). Conclusions: Promoter methylation-mediated inactivation of PMS2 gene participates in carcinogenesis and development of NPC. PMS2 may be

Examination of Global Methylation and Targeted Imprinted Genes in Prader-Willi Syndrome.

PubMed

Manzardo, A M; Butler, M G

2016-01-01

Methylation changes observed in Prader-Willi syndrome (PWS) may impact global methylation as well as regional methylation status of imprinted genes on chromosome 15 (in cis) or other imprinted obesity-related genes on other chromosomes (in trans) leading to differential effects on gene expression impacting obesity phenotype unique to (PWS). Characterize the global methylation profiles and methylation status for select imprinted genes associated with obesity phenotype in a well-characterized imprinted, obesity-related syndrome (PWS) relative to a cohort of obese and non-obese individuals. Global methylation was assayed using two methodologies: 1) enriched LINE-1 repeat sequences by EpigenDx and 2) ELISA-based immunoassay method sensitive to genomic 5-methylcytosine by Epigentek. Target gene methylation patterns at selected candidate obesity gene loci were determined using methylation-specific PCR. Study participants were recruited as part of an ongoing research program on obesity-related genomics and Prader-Willi syndrome. Individuals with non-syndromic obesity (N=26), leanness (N=26) and PWS (N=39). A detailed characterization of the imprinting status of select target genes within the critical PWS 15q11-q13 genomic region showed enhanced cis but not trans methylation of imprinted genes. No significant differences in global methylation were found between non-syndromic obese, PWS or non-obese controls. None. Percentage methylation and the methylation index. The methylation abnormality in PWS due to errors of genomic imprinting effects both upstream and downstream effectors in the 15q11-q13 region showing enhanced cis but not trans methylation of imprinted genes. Obesity in our subject cohorts did not appear to impact global methylation levels using the described methodology.

Validation of methylation-sensitive high-resolution melting (MS-HRM) for the detection of stool DNA methylation in colorectal neoplasms.

PubMed

Xiao, Zhujun; Li, Bingsheng; Wang, Guozhen; Zhu, Weisi; Wang, Zhongqiu; Lin, Jinfeng; Xu, Angao; Wang, Xinying

2014-04-20

Methylation-sensitive high-resolution melting (MS-HRM) is a new technique for assaying DNA methylation, but its feasibility for assaying stool in patients with colorectal cancer (CRC) is unknown. First, the MS-HRM and methylation-specific PCR (MSP) detection limits were tested. Second, the methylation statuses of SFRP2 and VIM were analyzed in stool samples by MS-HRM, and in matching tumor and normal colon tissues via bisulfite sequencing PCR (BSP). Third, a case-control study evaluated the diagnostic sensitivity and specificity of MS-HRM relative to results obtained with MSP and the fecal immunochemical test (FIT). Finally, the linearity and reproducibility of MS-HRM were assessed. The detection limits of MS-HRM and MSP were 1% and 5%, respectively. The diagnostic sensitivities of MS-HRM (87.3%, 55/63) in stool and BSP in matching tumor tissue (92.1%, 58/63) were highly consistent (κ=0.744). The MS-HRM assay detected 92.5% (37/40) methylation in CRCs, 94.4% (34/36) in advanced adenomas, and 8.8% (5/57) in normal controls. The results of MS-HRM analysis were stable and reliable and showed fairly good linearity for both SFRP2 (P<0.001, R(2)=0.957) and VIM (P<0.001, R(2)=0.954). MS-HRM shows potential for CRC screening. Copyright © 2014 Elsevier B.V. All rights reserved.

Brain MRI Characteristics of Patients with Anti-N-Methyl-D-Aspartate Receptor Encephalitis and Their Associations with 2-Year Clinical Outcome.

PubMed

Zhang, T; Duan, Y; Ye, J; Xu, W; Shu, N; Wang, C; Li, K; Liu, Y

2018-05-01

Anti- N -methyl-D-aspertate receptor encephalitis is an autoimmune-mediated disease without specific brain MRI features. Our aim was to investigate the brain MR imaging characteristics of anti- N -methyl-D-aspartate receptor encephalitis and their associations with clinical outcome at a 2-year follow-up. We enrolled 53 patients with anti- N -methyl-D-aspartate receptor encephalitis and performed 2-year follow-up. Brain MRIs were acquired for all patients at the onset phase. The brain MR imaging manifestations were classified into 4 types: type 1: normal MR imaging findings; type 2: only hippocampal lesions; type 3: lesions not involving the hippocampus; and type 4: lesions in both the hippocampus and other brain areas. The modified Rankin Scale score at 2-year follow-up was assessed, and the association between the mRS and onset brain MR imaging characteristics was evaluated. Twenty-eight (28/53, 53%) patients had normal MR imaging findings (type 1), and the others (25/53, 47%) had abnormal MRI findings: type 2: 7 patients (13%); type 3: seven patients (13%); and type 4: eleven patients (21%). Normal brain MRI findings were more common in female patients ( P = .02). Psychiatric and behavioral abnormalities were more common in adults ( P = .015), and autonomic symptoms ( P = .025) were more common in pediatric patients. The presence of hippocampal lesions ( P = .008, OR = 9.584; 95% CI, 1.803-50.931) and relapse ( P = .043, OR = 0.111; 95% CI, 0.013-0.930) was associated with poor outcome. Normal brain MRI findings were observed in half of the patients. Lesions in the hippocampus were the most common MR imaging abnormal finding. The presence of hippocampal lesions is the main MR imaging predictor for poor prognosis in patients with anti- N -methyl-D-aspartate receptor encephalitis. © 2018 by American Journal of Neuroradiology.

Crystal structure of di-μ-chlorido-bis-(chlorido-{N1,N1-diethyl-N4-[(pyridin-2-yl-κN)methyl-idene]benzene-1,4-di-amine-κN4}mercury(II)).

PubMed

Faizi, Md Serajul Haque; Dege, Necmi; Goleva, Kateryna

2017-06-01

The title dinuclear mercury(II) complex, [Hg 2 Cl 4 (C 16 H 19 N 3 ) 2 ], synthesized from the pyridine-derived Schiff base ( E )- N 1 , N 1 -diethyl- N 4 -[(pyridin-2-yl)methyl-idene]benzene-1,4-di-amine (DPMBD), has inversion symmetry. The five-coordinated Hg II atoms have distorted square-pyramidal stereochemistry comprising two N-atom donors from bidentate chelate BPMBD ligands and three Cl-atom donors, two bridging and one monodentate. The dihedral angle between the benzene and the pyridine rings in the BPMBD ligand is 7.55 (4)°. In the crystal, the dinuclear mol-ecules are linked by weak C-H⋯Cl hydrogen bonds, forming zigzag ribbons lying parallel to [001]. Also present in the structure are π-π inter-actions between benzene and pyridine rings [minimum ring-centroid separation = 3.698 (8) Å].

Inhibition of selenocysteine tRNA[Ser]Sec aminoacylation provides evidence that aminoacylation is required for regulatory methylation of this tRNA

PubMed Central

Kim, Jin Young; Carlson, Bradley A.; Xu, Xue-Ming; Zeng, Yu; Chen, Shawn; Gladyshev, Vadim N.; Lee, Byeong Jae; Hatfield, Dolph L.

2011-01-01

There are two isoforms of selenocysteine (Sec) tRNA[Ser]Sec that differ by a single methyl group, Um34. The non-Um34 isoform supports the synthesis of a subclass of selenoproteins, designated housekeeping, while the Um34 isoform supports the expression of another subclass, designated stress-related selenoproteins. Herein, we investigated the relationship between tRNA[Ser]Sec aminoacylation and Um34 synthesis which is the last step in the maturation of this tRNA. Mutation of the discriminator base at position 73 in tRNA[Ser]Sec dramatically reduced aminoacylation with serine, as did an inhibitor of seryl-tRNA synthetase, SB-217452. Although both the mutation and the inhibitor prevented Um34 synthesis, neither precluded the synthesis of any other of the known base modifications on tRNA[Ser]Sec following microinjection and incubation of the mutant tRNA[Ser]Sec transcript, or the wild type transcript along with inhibitor, in Xenopus oocytes. The data demonstrate that Sec tRNA[Ser]Sec must be aminoacylated for Um34 addition. The fact that selenium is required for Um34 methylation suggests that Sec must be attached to its tRNA for Um34 methylation. This would explain why selenium is essential for the function of Um34 methylase and provides further insights into the hierarchy of selenoprotein expression. PMID:21624347

N-(/sup 11/C)-methyl-p-substituted phentermine analogs as potential brain blood flow agents for positron tomography

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

Kizuka, H.; Elmaleh, D.R.; Boudreaux, G.J.

The addition of a methyl group to the ..cap alpha..-position of amphetamine increases both the lipophilicity of the agent and its resistance to metabolism by monoamine oxidase. In addition, since tritium substituted phenteramine analog studies suggested that the p-halo phentermines had a greater concentration in the brain and prolonged retention time, the authors evaluated the biological behavior of positron labeled ..cap alpha..-methylamphetamine (phenteramine) in rats, dogs and monkeys. The N-(/sup 11/C) methyl analogs of p-chloro (I) and p-fluoro (II) phentermines were prepared by methylation of their primary amines using /sup 11/Ch/sub 3/I. Biodistribution studies in rats shows brain uptake ismore » in the range of 1% dose/gr at 5 and 15 min for both agents. The activity in blood and eyes is low. Sequential images of the dogs' brain over 1 hour revealed a clearance of <15%. Images of the monkey brain were also obtained using a MGH positron camera PCR-I.« less

-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

49 CFR 173.193 - Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc.

Code of Federal Regulations, 2010 CFR

2010-10-01

... methyl bromide or methyl chloride mixtures, etc. 173.193 Section 173.193 Transportation Other Regulations... bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc. (a) Bromoacetone must be...) Bromoacetone, methyl bromide, chloropicrin and methyl bromide mixtures, chloropicrin and methyl chloride...

Methyl-DEAE-dextran: a candidate biomaterial.

PubMed

Zambito, Ylenia; Baggiani, Andrea; Carelli, Vera; Serafini, Maria Francesca; Di Colo, Giacomo

2004-01-01

The full quaternisation of DEAE-dextran was successfully attempted and an application of the quaternised product was suggested. Commercial DEAE-dextran was reacted with iodomethane at 60 degrees C in the presence of NaOH. The raw product was purified by dialysis, during which the iodide ion was replaced by chloride. N-methylation and O-methylation resulted from the reaction. A second methylation step produced no further changes in the molecule. Alkalimetry indicated the absence of amino groups in the methylated polymer molecule, thus testifying to a complete quaternisation. N-acetylcysteine (AcCy) was neutralised with the polymer in the hydroxide form, thus obtaining the methyl DEAE-dextran salt of AcCy (Me-DEAE-dextran/AcCy), whereby an ophthalmic formulation for the treatment of the dry eye syndrome was prepared. For comparison, the neutral AcCy salt of commercial DEAE-dextran (DEAE-dextran/AcCy) was prepared. The AcCy content in Me-DEAE-dextran/AcCy was higher than in DEAE-dextran/AcCy (23 vs 13%), while the viscosity of a solution containing the salt concentration corresponding to the therapeutic AcCy concentration (4%w/v) was lower with the former compared to the latter salt (20.5 vs 23.9 mPa s). Both solutions were ipotonic (245 mOsm/kg), whereas the commercial Tirocular is strongly hypertonic (900 mOsm/kg) and irritant.

Discovery of 5-substituted tetrahydronaphthalen-2yl-methyl with N-phenyl-N-(piperidin-4-yl)propionamide derivatives as potent opioid receptor ligands.

PubMed

Deekonda, Srinivas; Wugalter, Lauren; Kulkarni, Vinod; Rankin, David; Largent-Milnes, Tally M; Davis, Peg; Bassirirad, Neemah M; Lai, Josephine; Vanderah, Todd W; Porreca, Frank; Hruby, Victor J

2015-09-15

A new series of novel opioid ligands have been designed and synthesized based on the 4-anilidopiperidine scaffold containing a 5-substituted tetrahydronaphthalen-2yl)methyl group with different N-phenyl-N-(piperidin-4-yl)propionamide derivatives to study the biological effects of these substituents on μ and δ opioid receptor interactions. Recently our group reported novel 4-anilidopiperidine analogues, in which several aromatic ring-contained amino acids were conjugated with N-phenyl-N-(piperidin-4-yl)propionamide and examined their biological activities at the μ and δ opioid receptors. In continuation of our efforts in these novel 4-anilidopiperidine analogues, we took a peptidomimetic approach in the present design, in which we substituted aromatic amino acids with tetrahydronaphthalen-2yl methyl moiety with amino, amide and hydroxyl substitutions at the 5th position. In in vitro assays these ligands, showed very good binding affinity and highly selective toward the μ opioid receptor. Among these, the lead ligand 20 showed excellent binding affinity (2 nM) and 5000 fold selectivity toward the μ opioid receptor, as well as functional selectivity in GPI assays (55.20 ± 4.30 nM) and weak or no agonist activities in MVD assays. Based on the in vitro bioassay results the lead compound 20 was chosen for in vivo assessment for efficacy in naïve rats after intrathecal administration. Compound 20 was not significantly effective in alleviating acute pain. This discrepancy between high in vitro binding affinity, moderate in vitro activity, and low in vivo activity may reflect differences in pharmacodynamics (i.e., engaging signaling pathways) or pharmacokinetics (i.e., metabolic stability). In sum, our data suggest that further optimization of this compound 20 is required to enhance in vivo activity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Analysis of DNA methylation level by methylation-sensitive amplification polymorphism in half smooth tongue sole ( Cynoglossus semilaevis) subjected to salinity stress

NASA Astrophysics Data System (ADS)

Li, Siping; He, Feng; Wen, Haishen; Li, Jifang; Si, Yufeng; Liu, Mingyuan; He, Huiwen; Huang, Zhengju

2017-04-01

Increasingly arisen environmental constraints may contribute to heritable phenotypic variation including methylation changes, which can help the animals with development, growth and survival. In this study, we assessed the DNA methylation levels in three tissues (gonad, kidney and gill) of half smooth tongue sole under the salinity stress. The methylation-sensitive amplification polymorphism (MSAP) technique was applied to illustrate the regulation of epigenetic mechanism in environmental stimuli. Fish were subjected to 15 salinity treatment for 7 and 60 days, respectively. A total of 11259 fragments were amplified with 8 pairs of selective primers. The levels of methylated DNA in different tissues of females and males without salinity stress were analyzed, which were 32.76% and 47.32% in gonad; 38.13% and 37.69% in kidney; 37.58% and 34.96% in gill, respectively. In addition, the significant difference was observed in gonad between females and males, indicating that discrepant regulation in gonadal development and differentiation may involve sex-related genes. Further analysis showed that total and hemi-methylation were significantly decreased under 15 salinity for 7 days, probably resulting in up-regulating salt-tolerance genes expression to adjust salt changing. With the adjustment for 60 days, total and hemi-methylation prominently went back to its normal levels to obtain equilibrium. Particularly, full methylation levels were steady along with salinity stress to maintain the stability of gene expression. Additionally, the data showed that gonads in females and gills in males were superior in adaptability. As a result, DNA methylation regulates tissue- specific epiloci, and may respond to salinity stress by regulating gene expression to maintain animal survival and activity.

Shotgun Bisulfite Sequencing of the Betula platyphylla Genome Reveals the Tree’s DNA Methylation Patterning

PubMed Central

Su, Chang; Wang, Chao; He, Lin; Yang, Chuanping; Wang, Yucheng

2014-01-01

DNA methylation plays a critical role in the regulation of gene expression. Most studies of DNA methylation have been performed in herbaceous plants, and little is known about the methylation patterns in tree genomes. In the present study, we generated a map of methylated cytosines at single base pair resolution for Betula platyphylla (white birch) by bisulfite sequencing combined with transcriptomics to analyze DNA methylation and its effects on gene expression. We obtained a detailed view of the function of DNA methylation sequence composition and distribution in the genome of B. platyphylla. There are 34,460 genes in the whole genome of birch, and 31,297 genes are methylated. Conservatively, we estimated that 14.29% of genomic cytosines are methylcytosines in birch. Among the methylation sites, the CHH context accounts for 48.86%, and is the largest proportion. Combined transcriptome and methylation analysis showed that the genes with moderate methylation levels had higher expression levels than genes with high and low methylation. In addition, methylated genes are highly enriched for the GO subcategories of binding activities, catalytic activities, cellular processes, response to stimulus and cell death, suggesting that methylation mediates these pathways in birch trees. PMID:25514241

Examination of Global Methylation and Targeted Imprinted Genes in Prader-Willi Syndrome

PubMed Central

Manzardo, AM; Butler, MG

2016-01-01

Context Methylation changes observed in Prader-Willi syndrome (PWS) may impact global methylation as well as regional methylation status of imprinted genes on chromosome 15 (in cis) or other imprinted obesity-related genes on other chromosomes (in trans) leading to differential effects on gene expression impacting obesity phenotype unique to (PWS). Objective Characterize the global methylation profiles and methylation status for select imprinted genes associated with obesity phenotype in a well-characterized imprinted, obesity-related syndrome (PWS) relative to a cohort of obese and non-obese individuals. Design Global methylation was assayed using two methodologies: 1) enriched LINE-1 repeat sequences by EpigenDx and 2) ELISA-based immunoassay method sensitive to genomic 5-methylcytosine by Epigentek. Target gene methylation patterns at selected candidate obesity gene loci were determined using methylation-specific PCR. Setting Study participants were recruited as part of an ongoing research program on obesity-related genomics and Prader-Willi syndrome. Participants Individuals with non-syndromic obesity (N=26), leanness (N=26) and PWS (N=39). Results A detailed characterization of the imprinting status of select target genes within the critical PWS 15q11-q13 genomic region showed enhanced cis but not trans methylation of imprinted genes. No significant differences in global methylation were found between non-syndromic obese, PWS or non-obese controls. Intervention None. Main outcome measures Percentage methylation and the methylation index. Conclusion The methylation abnormality in PWS due to errors of genomic imprinting effects both upstream and downstream effectors in the 15q11-q13 region showing enhanced cis but not trans methylation of imprinted genes. Obesity in our subject cohorts did not appear to impact global methylation levels using the described methodology. PMID:28111641

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.

DNA methylation analysis of phenotype specific stratified Indian population.

PubMed

Rotti, Harish; Mallya, Sandeep; Kabekkodu, Shama Prasada; Chakrabarty, Sanjiban; Bhale, Sameer; Bharadwaj, Ramachandra; Bhat, Balakrishna K; Dedge, Amrish P; Dhumal, Vikram Ram; Gangadharan, G G; Gopinath, Puthiya M; Govindaraj, Periyasamy; Joshi, Kalpana S; Kondaiah, Paturu; Nair, Sreekumaran; Nair, S N Venugopalan; Nayak, Jayakrishna; Prasanna, B V; Shintre, Pooja; Sule, Mayura; Thangaraj, Kumarasamy; Patwardhan, Bhushan; Valiathan, Marthanda Varma Sankaran; Satyamoorthy, Kapaettu

2015-05-08

DNA methylation and its perturbations are an established attribute to a wide spectrum of phenotypic variations and disease conditions. Indian traditional system practices personalized medicine through indigenous concept of distinctly descriptive physiological, psychological and anatomical features known as prakriti. Here we attempted to establish DNA methylation differences in these three prakriti phenotypes. Following structured and objective measurement of 3416 subjects, whole blood DNA of 147 healthy male individuals belonging to defined prakriti (Vata, Pitta and Kapha) between the age group of 20-30years were subjected to methylated DNA immunoprecipitation (MeDIP) and microarray analysis. After data analysis, prakriti specific signatures were validated through bisulfite DNA sequencing. Differentially methylated regions in CpG islands and shores were significantly enriched in promoters/UTRs and gene body regions. Phenotypes characterized by higher metabolism (Pitta prakriti) in individuals showed distinct promoter (34) and gene body methylation (204), followed by Vata prakriti which correlates to motion showed DNA methylation in 52 promoters and 139 CpG islands and finally individuals with structural attributes (Kapha prakriti) with 23 and 19 promoters and CpG islands respectively. Bisulfite DNA sequencing of prakriti specific multiple CpG sites in promoters and 5'-UTR such as; LHX1 (Vata prakriti), SOX11 (Pitta prakriti) and CDH22 (Kapha prakriti) were validated. Kapha prakriti specific CDH22 5'-UTR CpG methylation was also found to be associated with higher body mass index (BMI). Differential DNA methylation signatures in three distinct prakriti phenotypes demonstrate the epigenetic basis of Indian traditional human classification which may have relevance to personalized medicine.

Mechanism of error-free DNA synthesis across N1-methyl-deoxyadenosine by human DNA polymerase-ι

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

Jain, Rinku; Choudhury, Jayati Roy; Buku, Angeliki

N1-methyl-deoxyadenosine (1-MeA) is formed by methylation of deoxyadenosine at the N1 atom. 1-MeA presents a block to replicative DNA polymerases due to its inability to participate in Watson-Crick (W-C) base pairing. Here we determine how human DNA polymerase-ι (Polι) promotes error-free replication across 1-MeA. Steady state kinetic analyses indicate that Polι is ~100 fold more efficient in incorporating the correct nucleotide T versus the incorrect nucleotide C opposite 1-MeA. To understand the basis of this selectivity, we determined ternary structures of Polι bound to template 1-MeA and incoming dTTP or dCTP. In both structures, template 1-MeA rotates to the synmore » conformation but pairs differently with dTTP versus dCTP. Thus, whereas dTTP partakes in stable Hoogsteen base pairing with 1-MeA, dCTP fails to gain a “foothold” and is largely disordered. Together, our kinetic and structural studies show how Polι maintains discrimination between correct and incorrect incoming nucleotide opposite 1-MeA in preserving genome integrity.« less

Rotational Spectrum and Conformational Analysis of N-methyl-2-aminoethanol: Insights into the Shape of Adrenergic Neurotransmitters

NASA Astrophysics Data System (ADS)

Calabrese, Camilla; Maris, Assimo; Evangelisti, Luca; Piras, Anna; Parravicini, Valentina; Melandri, Sonia

2018-02-01

Abstract We describe an experimental and quantum chemical study for the accurate determination of the conformational space of small molecular systems governed by intramolecular non-covalent interactions. The model systems investigated belong to the biological relevant aminoalcohol’s family, and include 2-aminophenylethanol, 2-methylaminophenylethanol, noradrenaline, adrenaline 2-aminoethanol and N-methyl-2-aminoethanol. For the latter molecule, the rotational spectrum in the 6-18 and 59.6-74.4 GHz ranges was recorded in the isolated conditions of a free jet expansion. Based on the analysis of the rotational spectra, two different conformational species and 11 isotopologues were observed and their spectroscopic constants, including 14N-nuclear hyperfine coupling constants and methyl internal rotation barriers, were determined. From the experimental data a structural determination was obtained, which was also used to benchmark accurate quantum chemical calculations on the whole conformational space. Atom in molecules and non-covalent interactions theories allowed the characterization of the position of the intramolecular non-covalent interactions and the energies involved, highlighting the subtle balance responsible of the stabilization of all the molecular systems.

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

PEGylated N-methyl-S-methyl dithiocarbazate as a new reagent for the high-yield preparation of nitrido Tc-99m and Re-188 radiopharmaceuticals.

PubMed

Boschi, Alessandra; Massi, Alessandro; Uccelli, Licia; Pasquali, Micol; Duatti, Adriano

2010-11-01

A novel nitrido nitrogen atom donor for the preparation of (99m)Tc and (188)Re radiopharmaceuticals containing a metal-nitrogen multiple bond is presented. HO(2)C-PEG(600)-DTCZ was obtained by conjugation of N-methyl-S-methyl dithiocarbazate [H(2)N-N(CH(3))-C(S)SCH(3), HDTCZ] with polyethylene glycol 600 (PEG(600)). Asymmetrical heterocomplexes of the type [M(N)(PNP)(B)](0/+) (M=(99m)Tc, (188)Re; PNP=diphosphine ligands, B=DBODC, DEDC, NSH, H(2)OS, CysNAc, HDTCZ) and symmetrical nitride compounds of the type [M(N)(L)(2)] (L=DEDC, DPDC) have been prepared in high yield by using the newly designed nitride nitrogen atom donor HO(2)C-PEG(600)-DTCZ. A two-step procedure was applied for preparing the above symmetrical and asymmetrical complexes. The first step involved the preliminary formation of a mixture of nitride Tc-99m or Re-188 precursors, which contained the [M≡N](2+) core, through reduction of generator-eluted (99m)Tc-pertechnetate or (188)Re-perrhenate with thin (II) chloride in the presence of HO(2)C-PEG(600)-DTCZ. In the second step, the intermediate mixture was converted either in the final mixed asymmetrical complex by the simultaneous addition of diphosphine ligand and the suitable bidentate ligand B, or in the final symmetrical complex by the only addition of the bidentate ligand L. It was also demonstrated that the novel water-soluble nitride nitrogen atom donor HO(2)C-PEG(600)-DTCZ did not show coordinating properties toward the M≡N ((99m)Tc, (188)Re) core. Biodistribution studies in rats of the hitherto unreported [(99m)Tc(N)(PNP(3))DTCZ](+) and [(99m)Tc(N)(PNP(5))DTCZ](+) complexes showed that they selectively localize in the myocardium of rats with a favourable heart-to-lung and heart-to-liver uptake ratios. In particular, the heart-to-lung and heart-to-liver uptake ratios dramatically increased in the interval between 60 and 120 min postinjection. Hence, the combination of the favourable chemical and biological properties of HO(2)C-PEG(600)-DTCZ

Crystal structures of N-(3-fluoro-benzo-yl)benzene-sulfonamide and N-(3-fluoro-benzo-yl)-4-methyl-benzene-sulfonamide.

PubMed

Suchetan, P A; Naveen, S; Lokanath, N K; Lakshmikantha, H N; Srivishnu, K S; Supriya, G M

2016-04-01

The crystal structures of two N-(aryl-sulfon-yl)aryl-amides, namely N-(3-fluoro-benzo-yl)benzene-sulfonamide, C13H10FNO3S, (I), and N-(3-fluoro-benzo-yl)-4-methyl-benzene-sulfonamide, C14H12FNO3S, (II), are described and compared with related structures. The dihedral angle between the benzene rings is 82.73 (10)° in (I) compared to 72.60 (12)° in (II). In the crystal of (I), the mol-ecules are linked by C-H⋯O and C-H⋯π inter-actions, resulting in a three-dimensional grid-like architecture, while C-H⋯O inter-actions lead to one-dimensional ribbons in (II). The crystals of both (I) and (II) feature strong but non-structure-directing N-H⋯O hydrogen bonds with R 2 (2)(8) ring motifs. The structure of (I) also features π-π stacking inter-actions.

Quantification of four major metabolites of embryotoxic N-methyl- and N-ethyl-2-pyrrolidone in human urine by cooled-injection gas chromatography and isotope dilution mass spectrometry.

PubMed

Schindler, Birgit K; Koslitz, Stephan; Meier, Swetlana; Belov, Vladimir N; Koch, Holger M; Weiss, Tobias; Brüning, Thomas; Käfferlein, Heiko U

2012-04-17

N-Methyl- and N-ethyl-2-pyrollidone (NMP and NEP) are frequently used industrial solvents and were shown to be embryotoxic in animal experiments. We developed a sensitive, specific, and robust analytical method based on cooled-injection (CIS) gas chromatography and isotope dilution mass spectrometry to analyze 5-hydroxy-N-ethyl-2-pyrrolidone (5-HNEP) and 2-hydroxy-N-ethylsuccinimide (2-HESI), two newly identified presumed metabolites of NEP, and their corresponding methyl counterparts (5-HNMP, 2-HMSI) in human urine. The urine was spiked with deuterium-labeled analogues of these metabolites. The analytes were separated from urinary matrix by solid-phase extraction and silylated prior to quantification. Validation of this method was carried out by using both, spiked pooled urine samples and urine samples from 56 individuals of the general population with no known occupational exposure to NMP and NEP. Interday and intraday imprecision was better than 8% for all metabolites, while the limits of detection were between 5 and 20 μg/L depending on the analyte. The high sensitivity of the method enables us to quantify NMP and NEP metabolites at current environmental exposures by human biomonitoring.

Increased Frequency of CpG Island Methylator Phenotype and CDH1 Methylation in a Gastric Cancer High-Risk Region of China1

PubMed Central

Zhang, Kai-Li; Sun, Yuan; Li, Yan; Liu, Ming; Qu, Bo; Cui, Shu-Hong; Kong, Qing-You; Chen, Xiao-Yan; Li, Hong; Liu, Jia

2008-01-01

This study aimed to profile the methylation statuses of CDH1/E-cadherin and five CpG island methylator phenotype (CIMP)-associated genes (p16, hMLH1, MINT1, MINT2, and MINT31) in gastric specimens of 47 Dalian long-term residents with and 31 without gastric cancers (GCs). CIMP patterns were classified as CIMP-H with over three methylated genes, CIMP-L with one to two methylated genes, and CIMP-N without methylation. Of 47 GC cases, 24 (51.1%) were CIMP-H, 18 (38.3%) were CIMP-L, and 5 (10.6%) were CIMP-N, whereas 5 of 21 (23.8%) premalignant lesions were CIMP-H and 15 (71.4%) were CIMP-L. CIMP-L was found in 75% (12/16) of GC-adjacent mucosa and in 38.7% (12/31) of mucosa from GC-free patients. CDH1 methylation occurred in 48.9% (23/47) of cancer, in 23.8% (5/21) of premalignant, and in 25% (4/16) of noncancerous tissues and was correlated with patients' age (P = .01), lymph node metastasis, and CIMP severity (P = .000–.028). Our results demonstrated that the frequencies of CIMP-H in Dalian GCs, CIMP-L, and p16 methylation in GC-adjacent tissues and in GC-free mucosa were much higher than those reported previously, indicating the elevated methylation pressure in this GC high-risk region. The close correlation between CDH1 methylation and CIMP severity suggests the necessity of their combination in GC prevention and earlier diagnosis. PMID:18607505

Characterization of N-methyl-D-aspartate-evoked taurine release in the developing and adult mouse hippocampus.

PubMed

Saransaari, P; Oja, S S

2003-01-01

Taurine is an inhibitory amino acid acting as an osmoregulator and neuroromodulator in the brain, with neuroprotective properties. The ionotropic glutamate receptor agonist N-methyl-D-aspartate (NMDA) greatly potentiates taurine release from brain preparations in both normal and ischemic conditions, the effect being particularly marked in the developing hippocampus. We now characterized the regulation of NMDA-stimulated taurine release from hippocampal slices from adult (3-month-old) and developing (7-day-old) mouse using a superfusion system. The NMDA-stimulated taurine release was receptor-mediated in both adult and developing mouse hippocampus. In adults, only NO-generating compounds, sodium nitroprusside, S-nitroso-N-acetylpenicillamine and hydroxylamine reduced the release, as did also NO synthase inhibitors, 7-nitroindazole and nitroarginine, indicating that the release is mediated by the NO/cGMP pathway. On the other hand, the regulation of the NMDA-evoked taurine release proved to be somewhat complex in the immature hippocampus. It was not affected by the NOergic compounds, but enhanced by the protein kinase C activator 4 beta-phorbol 12-myristate 13-acetate and adenosine receptor A(1) agonists, N(6)-cyclohexyladenosine and R(-)N(6)-(2-phenylisopropyl)adenosine in a receptor-mediated manner. The activation of both ionotropic 2-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors and metabotropic glutamate group I receptors also enhanced the evoked release. The NMDA-receptor-stimulated taurine release could be a part of the neuroprotective properties of taurine, being important particularly under cell-damaging conditions in the developing hippocampus and hence preventing excitotoxicity.

Methylation-specific digital karyotyping of HPV16E6E7-expressing human keratinocytes identifies novel methylation events in cervical carcinogenesis.

PubMed

Steenbergen, Renske D M; Ongenaert, Maté; Snellenberg, Suzanne; Trooskens, Geert; van der Meide, Wendy F; Pandey, Deeksha; Bloushtain-Qimron, Noga; Polyak, Kornelia; Meijer, Chris J L M; Snijders, Peter J F; Van Criekinge, Wim

2013-09-01

Transformation of epithelial cells by high-risk human papillomavirus (hrHPV) types can lead to anogenital carcinomas, particularly cervical cancer, and oropharyngeal cancers. This process is associated with DNA methylation alterations, often affecting tumour suppressor gene expression. This study aimed to comprehensively unravel genome-wide DNA methylation events linked to a transforming hrHPV-infection, which is driven by deregulated expression of the viral oncogenes E6 and E7 in dividing cells. Primary human keratinocytes transduced with HPV16E6E7 and their untransduced counterparts were subjected to methylation-specific digital karyotyping (MSDK) to screen for genome-wide DNA-methylation changes at different stages of HPV-induced transformation. Integration of the obtained methylation profiles with genome-wide gene expression patterns of cervical carcinomas identified 34 genes with increased methylation in HPV-transformed cells and reduced expression in cervical carcinomas. For 12 genes (CLIC3, CREB3L1, FAM19A4, LFNG, LHX1, MRC2, NKX2-8, NPTX-1, PHACTR3, PRDM14, SOST and TNFSF13) specific methylation in HPV-containing cell lines was confirmed by semi-quantitative methylation-specific PCR. Subsequent analysis of FAM19A4, LHX1, NKX2-8, NPTX-1, PHACTR3 and PRDM14 in cervical tissue specimens showed increasing methylation levels for all genes with disease progression. All six genes were frequently methylated in cervical carcinomas, with highest frequencies (up to 100%) seen for FAM19A4, PHACTR3 and PRDM14. Analysis of hrHPV-positive cervical scrapes revealed significantly increased methylation levels of the latter three genes in women with high-grade cervical disease compared to controls. In conclusion, MSDK analysis of HPV16-transduced keratinocytes at different stages of HPV-induced transformation resulted in the identification of novel DNA methylation events, involving FAM19A4, LHX1, NKX2-8, PHACTR3 and PRDM14 genes in cervical carcinogenesis. These genes may

The impact of methylation quantitative trait loci (mQTLs) on active smoking-related DNA methylation changes.

PubMed

Gao, Xu; Thomsen, Hauke; Zhang, Yan; Breitling, Lutz Philipp; Brenner, Hermann

2017-01-01

Methylation quantitative trait loci (mQTLs) are the genetic variants that may affect the DNA methylation patterns of CpG sites. However, their roles in influencing the disturbances of smoking-related epigenetic changes have not been well established. This study was conducted to address whether mQTLs exist in the vicinity of smoking-related CpG sites (± 50 kb) and to examine their associations with smoking exposure and all-cause mortality in older adults. We obtained DNA methylation profiles in whole blood samples by Illumina Infinium Human Methylation 450 BeadChip array of two independent subsamples of the ESTHER study (discovery set, n  = 581; validation set, n  = 368) and their corresponding genotyping data using the Illumina Infinium OncoArray BeadChip. After correction for multiple testing (FDR), we successfully identified that 70 out of 151 previously reported smoking-related CpG sites were significantly associated with 192 SNPs within the 50 kb search window of each locus. The 192 mQTLs significantly influenced the active smoking-related DNA methylation changes, with percentage changes ranging from 0.01 to 18.96%, especially for the weakly/moderately smoking-related CpG sites. However, these identified mQTLs were not directly associated with active smoking exposure or all-cause mortality. Our findings clearly demonstrated that if not dealt with properly, the mQTLs might impair the power of epigenetic-based models of smoking exposure to a certain extent. In addition, such genetic variants could be the key factor to distinguish between the heritable and smoking-induced impact on epigenome disparities. These mQTLs are of special importance when DNA methylation markers measured by Illumina Infinium assay are used for any comparative population studies related to smoking-related cancers and chronic diseases.

N-acetylcysteine reverses immunotoxic effects of methyl mercury and augments murine lymphocyte proliferation in vitro

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

Omara, F.; Fournier, M.; Bernier, J.

1995-12-31

N-Acetylcysteine (NAC) is a thiol antioxidant used clinically to treat chronic inflammatory lung disorders and acetaminophen poisoning in humans. The authors evaluated in vitro the effect of NAC on mitogen-induced blastogenesis in C57BI/6 mouse splenocytes by {sup 3}H-thymidine uptake, and its ability to protect against the immunotoxic effects of methyl mercury on lymphocyte proliferation. Lymphocyte proliferation stimulated by optimal and suboptimal concentrations of concanavalin A (Con A), lipopolysaccharide (LPS), or a combination of calcium ionophore A23187 and phorbol-12-myristate-13-acetate (PMA) were markedly enhanced by NAC. NAC itself was a weak mitogen. The kinetics of the NAC effect on splenocyte proliferation weremore » mitogen dependent. NAC enhanced Con A-induced splenocyte proliferation in a dose-dependent and linear manner but enhanced the LPS-induced response at 50--400 {micro}g/ml of NAC followed by a decline in response to control value at higher concentrations. In splenocytes stimulated with PMA plus A23187, NAC increased proliferation at 50--200 pg/ml followed by a constant response at 200--1,000 {micro}g/ml NAC. When splenocytes were stimulated with higher concentrations of Con A (10 {micro}g/ml) or LPS (150 {micro}g/ml) which markedly suppress splenocyte proliferation, NAC significantly enhanced the Con A-induced response and reversed the inhibitory effect of high concentrations of LPS. NAC also protected lymphocytes against mitogen activation-induced cell death. Methyl mercury at 5 {times} 10{sup {minus}7}--1 {times} 10{sup {minus}6} suppressed Con A- and LPS-induced splenocyte proliferation by over 80%. However, NAC completely reversed the immunotoxic effects of methyl mercury on the mitogen-induced splenocyte proliferation even when the cells were pre-incubated with methyl mercury for 6 or 24 hr before stimulation with the mitogens.« less

Gold-Catalyzed Solid-Phase Synthesis of 3,4-Dihydropyrazin-2(1H)-ones: Relevant Pharmacophores and Peptide Backbone Constraints.

PubMed

Přibylka, Adam; Krchňák, Viktor

2017-11-13

Here, we report the efficient solid-phase synthesis of N-propargyl peptides using Fmoc-amino acids and propargyl alcohol as key building blocks. Gold-catalyzed nucleophilic addition to the triple bond induced C-N bond formation, which triggered intramolecular cyclization, yielding 1,3,4-trisubstituted-5-methyl-3,4-dihydropyrazin-2(1H)-ones. Conformations of acyclic and constrained peptides were compared using a two-step conformer distribution analysis at the molecular mechanics level and density functional theory. The results indicated that the incorporation of heterocyclic molecular scaffold into a short peptide sequence adopted extended conformation of peptide chain. The amide bond adjacent to the constraint did not show significant preference for either cis or trans isomerism. Prepared model compounds demonstrate a proof of concept for gold-catalyzed polymer-supported synthesis of variously substituted 3,4-dihydropyrazin-2(1H)-ones for applications in drug discovery and peptide backbone constraints.

N4-cytosine DNA methylation regulates transcription and pathogenesis in Helicobacter pylori

PubMed Central

Kumar, Sumith; Karmakar, Bipul C; Nagarajan, Deepesh; Mukhopadhyay, Asish K; Morgan, Richard D; Rao, Desirazu N

2018-01-01

Abstract Many bacterial genomes exclusively display an N4-methyl cytosine base (m4C), whose physiological significance is not yet clear. Helicobacter pylori is a carcinogenic bacterium and the leading cause of gastric cancer in humans. Helicobacter pylori strain 26695 harbors a single m4C cytosine methyltransferase, M2.HpyAII which recognizes 5′ TCTTC 3′ sequence and methylates the first cytosine residue. To understand the role of m4C modification, M2.hpyAII deletion strain was constructed. Deletion strain displayed lower adherence to host AGS cells and reduced potential to induce inflammation and apoptosis. M2.hpyAII gene deletion strain exhibited reduced capacity for natural transformation, which was rescued in the complemented strain carrying an active copy of M2.hpyAII gene in the genome. Genome-wide gene expression and proteomic analysis were carried out to discern the possible reasons behind the altered phenotype of the M2.hpyAII gene deletion strain. Upon the loss of m4C modification a total of 102 genes belonging to virulence, ribosome assembly and cellular components were differentially expressed. The present study adds a functional role for the presence of m4C modification in H. pylori and provides the first evidence that m4C signal acts as a global epigenetic regulator in H. pylori. PMID:29481677

Garlic and associated allyl sulfur components inhibit N-methyl-N-nitrosourea induced rat mammary carcinogenesis.

PubMed

Schaffer, E M; Liu, J Z; Green, J; Dangler, C A; Milner, J A

1996-04-19

Our previous studies demonstrated that dietary garlic powder supplementation inhibits N-nitrosamine induced DNA alkylation in liver and mammary tissue. The present studies compared the impact of dietary supplementation with garlic powder or two garlic constituents, water-soluble S-allyl cysteine (SAC) and oil-soluble diallyl disulfide (DADS), on the incidence of mammary tumorigenesis induced by N-methyl-N-nitrosourea (MNU). Female Sprague-Dawley rats were fed semi-purified casein based diets with or without supplements of garlic powder(20g/kg), SAC (57 micromol/kg) or DADS (57 micromol/kg) for 2 weeks prior to treatment with MNU (15 mg/kg body wt). Garlic powder, SAC and DADS supplementation significantly delayed the onset of mammary tumors compared to rats receiving the unsupplemented diet. Tumor incidence 23 weeks after MNU treatment was reduced by 76, 41 and 53% in rats fed garlic, SAC and DADS, respectively, compared to controls (P<0.05). Total tumor number was reduced 81, 35 and 65% by these supplements, respectively (P<0.05). In a separate study the quantity of mammary DNA alkylation occurring 3 h after MNU treatment was reduced in rats fed garlic, SAC or DADS (P<0.05). Specifically, O(6)-methylguanine adducts were reduced by 27, 18 and 23% in rats fed supplemental garlic, SAC and DADS, respectively, compared to controls. N(7)-Methylguanine adducts decreased by 48, 22 and 21% respectively, compared to rats fed the control diet. These studies demonstrate that garlic and associated allyl sulfur components, SAC and DADS, are effective inhibitors of MNU-induced mammary carcinogenesis.

Alpha-Synuclein Produces Early Behavioral Alterations via Striatal Cholinergic Synaptic Dysfunction by Interacting With GluN2D N-Methyl-D-Aspartate Receptor Subunit.

PubMed

Tozzi, Alessandro; de Iure, Antonio; Bagetta, Vincenza; Tantucci, Michela; Durante, Valentina; Quiroga-Varela, Ana; Costa, Cinzia; Di Filippo, Massimiliano; Ghiglieri, Veronica; Latagliata, Emanuele Claudio; Wegrzynowicz, Michal; Decressac, Mickael; Giampà, Carmela; Dalley, Jeffrey W; Xia, Jing; Gardoni, Fabrizio; Mellone, Manuela; El-Agnaf, Omar Mukhtar; Ardah, Mustafa Taleb; Puglisi-Allegra, Stefano; Björklund, Anders; Spillantini, Maria Grazia; Picconi, Barbara; Calabresi, Paolo

2016-03-01

Advanced Parkinson's disease (PD) is characterized by massive degeneration of nigral dopaminergic neurons, dramatic motor and cognitive alterations, and presence of nigral Lewy bodies, whose main constituent is α-synuclein (α-syn). However, the synaptic mechanisms underlying behavioral and motor effects induced by early selective overexpression of nigral α-syn are still a matter of debate. We performed behavioral, molecular, and immunohistochemical analyses in two transgenic models of PD, mice transgenic for truncated human α-synuclein 1-120 and rats injected with the adeno-associated viral vector carrying wild-type human α-synuclein. We also investigated striatal synaptic plasticity by electrophysiological recordings from spiny projection neurons and cholinergic interneurons. We found that overexpression of truncated or wild-type human α-syn causes partial reduction of striatal dopamine levels and selectively blocks the induction of long-term potentiation in striatal cholinergic interneurons, producing early memory and motor alterations. These effects were dependent on α-syn modulation of the GluN2D-expressing N-methyl-D-aspartate receptors in cholinergic interneurons. Acute in vitro application of human α-syn oligomers mimicked the synaptic effects observed ex vivo in PD models. We suggest that striatal cholinergic dysfunction, induced by a direct interaction between α-syn and GluN2D-expressing N-methyl-D-aspartate receptors, represents a precocious biological marker of the disease. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

The role of N-methyl-D-aspartate receptors and nitric oxide in cochlear dopamine release.

PubMed

Halmos, G; Horváth, T; Polony, G; Fekete, A; Kittel, A; Vizi, E S; van der Laan, B F A M; Zelles, T; Lendvai, B

2008-06-23

Dopamine (DA) released from lateral olivocochlear (LOC) terminals may have a neuroprotective effect in the cochlea. To explore the role of N-methyl-d-aspartate (NMDA) receptors and nitric oxide (NO) in the modulation of a cochlear DA release, we measured the release of [3H]DA from isolated mouse cochlea in response to the application of NMDA. NMDA at 100 muM significantly increased the electrical-field stimulation-evoked and resting release of DA from the cochlea. The NO donor sodium nitroprusside enhanced the basal outflow of DA but failed to influence the evoked release. The administration of the nitric oxide synthase inhibitor N omega-nitro-L-arginine methyl ester (L-NAME) alone was ineffective, but it significantly inhibited the initial phase of the NMDA-induced elevation of DA outflow, which suggested the role of NO in the NMDA-induced DA release. The DA uptake inhibitor nomifensine increased the electrically evoked release of DA. Nomifensine failed to change the effect of NMDA on the resting or electrically-evoked DA release, which suggested that the uptake mechanism does not play a role in NMDA-evoked and NO-mediated DA release. In summary, we provide evidence that NO can modulate the release of DA from the cochlea following NMDA receptor activation, but does not affect the uptake of DA.

Determination of methyl mercury in dental-unit wastewater.

PubMed

Stone, Mark E; Cohen, Mark E; Liang, Lian; Pang, Patrick

2003-11-01

The objective of this investigation was to establish whether monomethyl mercury (MMHg) is present in dental-unit wastewater and if present, to determine the concentration relative to total mercury. Wastewater samples were collected over an 18-month period from three locations: at the dental chair; at a 30-chair clinic, and at a 107-chair clinic. Total mercury determinations were completed using United States Environmental Protection Agency's (USEPA) method 1631. MMHg was measured utilizing modified USEPA method 1630. The total mercury levels were found to be: 45182.11 microg/l (n=13, SD=68562.42) for the chair-side samples, 5350.74 microg/l (n=12, SD=2672.94) for samples at the 30-chair clinic, and 13439.13 microg/l (n=13, SD=9898.91) for samples at the107-chair clinic. Monomethyl Hg levels averaged 0.90 microg/l (n=13, SD=0.87) for chair side samples, 8.26 (n=12, SD=7.74) for the 30-chair facility, and 26.77 microg/l (n=13, SD=34.50) for 107-chair facility. By way of comparison, the MMHg levels for the open ocean, lakes and rain are orders of magnitude lower than methyl mercury levels seen in dental wastewater (part per billion levels for dental wastewater samples compared to part per trillion levels for samples from the environment). Environmentally important levels of MMHg were found to be present in dental-unit wastewater at concentrations orders of magnitude higher than seen in natural settings.

Development of an on-site screening system for amphetamine-type stimulant tablets with a portable attenuated total reflection Fourier transform infrared spectrometer.

PubMed

Tsujikawa, Kenji; Kuwayama, Kenji; Miyaguchi, Hajime; Kanamori, Tatsuyuki; Iwata, Yuko T; Yoshida, Takemi; Inoue, Hiroyuki

2008-02-04

We tried to develop a library search system using a portable, attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectrometer for on-site identification of 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyamphetamine (MDA) tablets. The library consisted of the spectra from mixtures of controlled drugs (e.g. MDMA and ketamine), adulterants (e.g. caffeine), and diluents (e.g. lactose). In the seven library search algorithms, the derivative correlation coefficient showed the best discriminant capability. This was enhanced by segmentation of the search area. The optimized search algorithm was validated by the positive (n=154, e.g. the standard mixtures containing the controlled drug, and the MDMA/MDA tablets confiscated) and negative samples (n=56, e.g. medicinal tablets). All validation samples except for four were judged truly. Final criteria for positive identification were decided on the basis of the results of the validation. In conclusion, a portable ATR-FT-IR spectrometer with our library search system would be a useful tool for on-site identification of amphetamine-type stimulant tablets.

Theoretical study of the regioselectivity of the interaction of 3-methyl-4-pyrimidone and 1-methyl-2-pyrimidone with Lewis acids.

PubMed

Kasende, Okuma Emile; Muya, Jules Tshishimbi; Broeckaert, Lies; Maes, Guido; Geerlings, Paul

2012-08-23

A density functional theory (DFT) study is performed to determine the stability of the complexes formed between either the N or O site of 3-methyl-4-pyrimidone and 1-methyl-2-pyrimidone molecules and different ligands. The studied ligands are boron and alkali Lewis acids, namely, B(CH(3))(3), HB(CH(3))(2), H(2)B(CH(3)), BH(3), H(2)BF, HBF(2), BF(3), Li(+), Na(+), and K(+). The acids are divided into two groups according to their hardness. The reactivity predictions, according to the molecular electrostatic potential (MEP) map and the natural bond orbital (NBO) analysis, are in agreement with the calculated relative stabilities. Our findings reveal a strong regioselectivity with borane and its derivatives preferring the nitrogen site in both pyrimidone isomers, while a preference for oxygen is observed for the alkali acids in the 3-methyl-4-pyrimidone molecule. The complexation of 1-methyl-2-pyrimidone with these hard alkali acids does not show any discrimination between the two sites due to the presence of a continuous delocalized density region between the nitrogen and the oxygen atoms. The preference of boron Lewis acids toward the N site is due to the stronger B-N bond as compared to the B-O bond. The influence of fluorine or methyl substitution on the boron atom is discussed through natural orbital analysis (NBO) concentrating on the overlap of the boron empty p-orbital with the F lone pairs and methyl hyperconjugation, respectively. The electrophilicity of the boron acids gives a good overall picture of the interaction capabilities with the Lewis base.

N-(Diphenyl­carbamo­yl)-N,N′,N′,N′′,N′′-penta­methyl­guanidinium tetra­phenyl­borate

PubMed Central

Tiritiris, Ioannis

2013-01-01

In the title salt, C19H25N4O+·C24H20B−, the C=N and C—N bond lengths in the CN3 unit are 1.3327 (8)/1.3364 (9) and 1.3802 (9) Å, indicating double- and single-bond character, respectively. The N—C—N angles are 118.77 (6), 120.29 (6) and 120.81 (6)°, showing only a small deviation of the CN3 plane from an ideal trigonal-planar geometry. The bonds between the N atoms and the terminal methyl C atoms all have values close to a typical single bond [1.4636 (9)–1.4772 (9) Å]. The crystal packing is caused by electrostatic inter­actions between cations and anions. PMID:23476477

Aberrant DNA methylation patterns of spermatozoa in men with unexplained infertility.

PubMed

Urdinguio, Rocío G; Bayón, Gustavo F; Dmitrijeva, Marija; Toraño, Estela G; Bravo, Cristina; Fraga, Mario F; Bassas, Lluís; Larriba, Sara; Fernández, Agustín F

2015-05-01

between DNA hypomethylation and regions corresponding to those which, in somatic cells, are enriched in the repressive histone mark H3K9me3, and between DNA hypermethylation and regions enriched in H3K4me1 and CTCF, suggesting that the relationship between chromatin context and aberrant DNA methylation of sperm in infertile men could be locus-dependent. Finally, we also show that DNA methylation patterns, not only at specific loci but also at several repetitive sequences (LINE-1, Alu Yb8, NBL2, D4Z4), were lower in sperm than in somatic cells. Interestingly, sperm samples at Alu Yb8 repetitive sequences of infertile patients showed significantly lower DNA methylation levels than controls. Our results are descriptive and further studies would be needed to elucidate the functional effects of aberrant DNA methylation on male fertility. Overall, our data suggest that aberrant sperm DNA methylation might contribute to fertility impairment in couples with unexplained infertility and they provide a promising basis for future research. This work has been financially supported by Fundación Cientifica de la AECC (to R.G.U.); IUOPA (to G.F.B.); FICYT (to E.G.T.); the Spanish National Research Council (CSIC; 200820I172 to M.F.F.); Fundación Ramón Areces (to M.F.F); the Plan Nacional de I+D+I 2008-2011/2013-2016/FEDER (PI11/01728 to AF.F., PI12/01080 to M.F.F. and PI12/00361 to S.L.); the PN de I+D+I 2008-20011 and the Generalitat de Catalunya (2009SGR01490). A.F.F. is sponsored by ISCIII-Subdirección General de Evaluación y Fomento de la Investigación (CP11/00131). S.L. is sponsored by the Researchers Stabilization Program from the Spanish National Health System (CES09/020). The IUOPA is supported by the Obra Social Cajastur, Spain. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of n-alkanols and a methyl ester on a transient potassium (IA) current in identified neurones from Helix aspersa.

PubMed Central

Winpenny, J P; Elliott, J R; Harper, A A

1992-01-01

1. A two-microelectrode voltage clamp was used to determine the effects of n-butanol, n-hexanol, n-octanol, n-decanol and methyl hexanoate on a transient potassium (IA) current in identified Helix aspersa neurones. Experiments were carried out at a temperature of 10-12 degrees C. 2. Each n-alkanol reversibly reduced the amplitude of the IA current. Logarithmic dose-response curves for the current reduction by each homologue were sigmoidal and had slope factors of around four. The concentrations required to reduce the peak (with time) current at -30 mV by 50% (ED50 +/- fitted standard error) were: 57 +/- 5 mM (n-butanol); 2.0 +/- 0.1 mM (n-hexanol); 0.28 +/- 0.02 mM (n-octanol) and 0.016 +/- 0.001 mM (n-decanol). Methyl hexanoate also reduced the current amplitude, with an ED50 of 1-2 mM. The Helix IA current thus showed a similar sensitivity to n-alkanols to that of squid and rat sodium currents but was rather more sensitive than the squid delayed rectifier potassium current. 3. The n-alkanol ED50 concentrations were used to calculate a standard free energy per methylene group for adsorption to a site of action in the cell of -3.1 +/- 0.2 kJ/mol. This suggested a hydrophobic site or sites of action. The regularity of the change in free energy with chain length was maintained up to, and including, n-decanol. This implied that the site(s) could accommodate a ten-carbon chain as readily as an eight-carbon chain. 4. The voltage dependencies of IA current activation and steady-state inactivation were not consistently altered by treatment with n-alkanols at concentrations around or above their current suppression ED50 concentrations. 5. The kinetics of current activation and inactivation were affected, particularly by lower chain length compounds. At 60 mM n-butanol reduced the time constant for development of inactivation of open channels (tau b) by 56%, while 0.016 mM n-decanol produced only a 13% reduction. n-Butanol (60 mM) also caused a substantial (76%) reduction

Synthesis, characterization, DNA-Binding, enzyme inhibition and antioxidant studies of new N-methylated derivatives of pyridinium amine

NASA Astrophysics Data System (ADS)

Zafar, Muhammad Naveed; Perveen, Fouzia; Nazar, Muhammad Faizan; Mughal, Ehsan Ullah; Rafique, Humera; Tahir, Muhammad Nawaz; Akbar, Muhammad Sharif; Zahra, Sabeen

2017-06-01

A series of novel N-methylated derivatives of pyridinium amine, [L1][Tf]-[L5][Tf], were synthesized and characterized by FTIR, NMR, MS and XRD analyses. Preliminary biological screening of these compounds including antioxidant, enzyme inhibition and DNA (salmon sperm) interaction studies were also carried out. The targeted compounds were synthesized by a melt reaction between 4-chloro-N-methyl pyridinium triflate and corresponding amines (1-naphthyl amine, o-ansidine, 2-nitroaniline, p-ansidine and cyclohexyl amine) at temperature of 230 °C. The DPPH radical antioxidant scavenging activities of these compounds at maximum concentration of 50 μg/mL were observed in the range of 60-70%. Acetylcholine esterase (AChE) and Butylcholine esterase (BChE) inhibitory activities of synthesized compounds at 2 mM concentration were also measured to be at maximum of 79 and 71% respectively. The spectral behavior of ligand-DNA obtained from photo-luminescent measurements showed that all ligands bind with DNA via non-covalent interactions. The binding constant values were determined by UV-visible and fluorescence spectroscopy and were quite close to that obtained from molecular docking studies.

Interrelations between Glycine Betaine Catabolism and Methionine Biosynthesis in Sinorhizobium meliloti Strain 102F34

PubMed Central

Barra, Lise; Fontenelle, Catherine; Ermel, Gwennola; Trautwetter, Annie; Walker, Graham C.; Blanco, Carlos

2006-01-01

Methionine is produced by methylation of homocysteine. Sinorhizobium meliloti 102F34 possesses only one methionine synthase, which catalyzes the transfer of a methyl group from methyl tetrahydrofolate to homocysteine. This vitamin B12-dependent enzyme is encoded by the metH gene. Glycine betaine can also serve as an alternative methyl donor for homocysteine. This reaction is catalyzed by betaine-homocysteine methyl transferase (BHMT), an enzyme that has been characterized in humans and rats. An S. meliloti gene whose product is related to the human BHMT enzyme has been identified and named bmt. This enzyme is closely related to mammalian BHMTs but has no homology with previously described bacterial betaine methyl transferases. Glycine betaine inhibits the growth of an S. meliloti bmt mutant in low- and high-osmotic strength media, an effect that correlates with a decrease in the catabolism of glycine betaine. This inhibition was not observed with other betaines, like homobetaine, dimethylsulfoniopropionate, and trigonelline. The addition of methionine to the growth medium allowed a bmt mutant to recover growth despite the presence of glycine betaine. Methionine also stimulated glycine betaine catabolism in a bmt strain, suggesting the existence of another catabolic pathway. Inactivation of metH or bmt did not affect the nodulation efficiency of the mutants in the 102F34 strain background. Nevertheless, a metH strain was severely defective in competing with the wild-type strain in a coinoculation experiment. PMID:17015658

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

p-Chlorophenyl methyl sulfide

Integrated Risk Information System (IRIS)

p - Chlorophenyl methyl sulfide ; CASRN 123 - 09 - 1 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 Assessments for N

Gestational N-hexane inhalation alters the expression of genes related to ovarian hormone production and DNA methylation states in adult female F1 rat offspring.

PubMed

Li, Hong; Zhang, Chenyun; Ni, Feng; Guo, Suhua; Wang, Wenxiang; Liu, Jing; Lu, Xiaoli; Huang, Huiling; Zhang, Wenchang

2015-12-15

Research has revealed that n-hexane can disrupt adult female endocrine functions; however, few reports have focused on endocrine changes in adult F1 females after maternal exposure during gestation. In this study, female Wistar rats inhaled 100, 500, 2500, or 12,500 ppm n-hexane for 4 h daily during their initial 20 gestational days. The F1 female offspring exhibited abnormal oestrus cycles. Compared with the controls, the in vitro-cultured ovarian granulosa cells of the 12,500 ppm group showed significantly reduced in vitro progesterone and oestradiol secretion. Elevated progesterone secretion was observed in the 500 ppm group, and decreased and significantly upregulated mRNA expression of the Star, Cyp11a1, Cyp17a1, and Hsd3b genes was observed in the 12,500 ppm and 500 ppm groups, respectively. The protein expression levels were consistent with the mRNA expression levels. Methylation screening of the promoter regions of these genes was performed using MeDIP-chip and confirmed by methylation-sensitive high-resolution melting (MS-HRM), and the observed methylation state changes of the promoter regions were correlated with the gene expression levels. The results suggest that the hormone levels in the female offspring after gestational n-hexane inhalation correspond to the expression levels and DNA methylation states of the hormone production genes. Copyright © 2015. Published by Elsevier Ireland Ltd.

DNA methylation markers for oral pre-cancer progression: A critical review.

PubMed

Shridhar, Krithiga; Walia, Gagandeep Kaur; Aggarwal, Aastha; Gulati, Smriti; Geetha, A V; Prabhakaran, Dorairaj; Dhillon, Preet K; Rajaraman, Preetha

2016-02-01

Although oral cancers are generally preceded by a well-established pre-cancerous stage, there is a lack of well-defined clinical and morphological criteria to detect and signal progression from pre-cancer to malignant tumours. We conducted a critical review to summarize the evidence regarding aberrant DNA methylation patterns as a potential diagnostic biomarker predicting progression. We identified all relevant human studies published in English prior to 30th April 2015 that examined DNA methylation (%) in oral pre-cancer by searching PubMed, Web-of-Science and Embase databases using combined key-searches. Twenty-one studies (18-cross-sectional; 3-longitudinal) were eligible for inclusion in the review, with sample sizes ranging from 4 to 156 affected cases. Eligible studies examined promoter region hyper-methylation of tumour suppressor genes in pathways including cell-cycle-control (n=15), DNA-repair (n=7), cell-cycle-signalling (n=4) and apoptosis (n=3). Hyper-methylated loci reported in three or more studies included p16, p14, MGMT and DAPK. Two longitudinal studies reported greater p16 hyper-methylation in pre-cancerous lesions transformed to malignancy compared to lesions that regressed (57-63.6% versus 8-32.1%; p<0.01). The one study that explored epigenome-wide methylation patterns reported three novel hyper-methylated loci (TRHDE; ZNF454; KCNAB3). The majority of reviewed studies were small, cross-sectional studies with poorly defined control groups and lacking validation. Whilst limitations in sample size and study design preclude definitive conclusions, current evidence suggests a potential utility of DNA methylation patterns as a diagnostic biomarker for oral pre-cancer progression. Robust studies such as large epigenome-wide methylation explorations of oral pre-cancer with longitudinal tracking are needed to validate the currently reported signals and identify new risk-loci and the biological pathways of disease progression. Copyright © 2015 The

DNA methylation markers for oral pre-cancer progression: A critical review

PubMed Central

Shridhar, Krithiga; Walia, Gagandeep Kaur; Aggarwal, Aastha; Gulati, Smriti; Geetha, A.V.; Prabhakaran, Dorairaj; Dhillon, Preet K.; Rajaraman, Preetha

2016-01-01

Summary Although oral cancers are generally preceded by a well-established pre-cancerous stage, there is a lack of well-defined clinical and morphological criteria to detect and signal progression from pre-cancer to malignant tumours. We conducted a critical review to summarize the evidence regarding aberrant DNA methylation patterns as a potential diagnostic biomarker predicting progression. We identified all relevant human studies published in English prior to 30th April 2015 that examined DNA methylation (%) in oral pre-cancer by searching PubMed, Web-of-Science and Embase databases using combined key-searches. Twenty-one studies (18-cross-sectional; 3-longitudinal) were eligible for inclusion in the review, with sample sizes ranging from 4 to 156 affected cases. Eligible studies examined promoter region hyper-methylation of tumour suppressor genes in pathways including cell-cycle-control (n = 15), DNA-repair (n = 7), cell-cycle-signalling (n = 4) and apoptosis (n = 3). Hyper-methylated loci reported in three or more studies included p16, p14, MGMT and DAPK. Two longitudinal studies reported greater p16 hyper-methylation in pre-cancerous lesions transformed to malignancy compared to lesions that regressed (57–63.6% versus 8–32.1%; p < 0.01). The one study that explored epigenome-wide methylation patterns reported three novel hyper-methylated loci (TRHDE; ZNF454; KCNAB3). The majority of reviewed studies were small, cross-sectional studies with poorly defined control groups and lacking validation. Whilst limitations in sample size and study design preclude definitive conclusions, current evidence suggests a potential utility of DNA methylation patterns as a diagnostic biomarker for oral pre-cancer progression. Robust studies such as large epigenome-wide methylation explorations of oral pre-cancer with longitudinal tracking are needed to validate the currently reported signals and identify new risk-loci and the biological pathways of disease

Addition reaction of methyl cinnamate with 2-amino-4- nitrophenol

NASA Astrophysics Data System (ADS)

Suryanti, Venty; Rakhman Wibowo, Fajar; Pranoto; Robingatun Isnaeni, Siti; Ratna Kumala Sari, Meiyanti; Handayani, Sekar

2016-02-01

A novel compound which have one N-H fragment and nitrophenyl group has been designed and synthesized from cinnamaldehyde. The reaction was conducted in 3 step reactions to give the final product. Firstly, cinnamaldehyde was converted into cinnamic acid, which was then esterified with methyl alcohol to obtained methyl cinnamate. The last step was the addition reaction between methyl cinnamate and 2-amino-4-nitrophenol to give a cinnamaldehyde derivative, namely methyl-3-(2-hidroksi-5-nitrophenyl amino)-3- phenylpropanoate.

RlmCD-mediated U747 methylation promotes efficient G748 methylation by methyltransferase RlmAII in 23S rRNA in Streptococcus pneumoniae; interplay between two rRNA methylations responsible for telithromycin susceptibility

PubMed Central

Shoji, Tatsuma; Takaya, Akiko; Sato, Yoshiharu; Kimura, Satoshi; Suzuki, Tsutomu; Yamamoto, Tomoko

2015-01-01

Adenine at position 752 in a loop of helix 35 from positions 745 to 752 in domain II of 23S rRNA is involved in binding to the ribosome of telithromycin (TEL), a member of ketolides. Methylation of guanine at position 748 by the intrinsic methyltransferase RlmAII enhances binding of telithromycin (TEL) to A752 in Streptococcus pneumoniae. We have found that another intrinsic methylation of the adjacent uridine at position 747 enhances G748 methylation by RlmAII, rendering TEL susceptibility. U747 and another nucleotide, U1939, were methylated by the dual-specific methyltransferase RlmCD encoded by SP_1029 in S. pneumoniae. Inactivation of RlmCD reduced N1-methylated level of G748 by RlmAII in vivo, leading to TEL resistance when the nucleotide A2058, located in domain V of 23S rRNA, was dimethylated by the dimethyltransferase Erm(B). In vitro methylation of rRNA showed that RlmAII activity was significantly enhanced by RlmCD-mediated pre-methylation of 23S rRNA. These results suggest that RlmCD-mediated U747 methylation promotes efficient G748 methylation by RlmAII, thereby facilitating TEL binding to the ribosome. PMID:26365244

Reversed-phase high-performance liquid chromatography purification of methyl esters of C(16)-C(28) polyunsaturated fatty acids in microalgae, including octacosaoctaenoic acid [28:8(n-3)].

PubMed

Mansour, Maged P

2005-12-02

A preparative reversed-phase (RP; C(18)) high-performance liquid chromatography (HPLC) method with gradient elution using acetonitrile (MeCN)-chloroform (CHCl(3)) (or dichloromethane (DCM)) and evaporative light-scattering detection (ELSD) with automatic multiple injection and fraction collection was used to purify milligram quantities of microalgal polyunsaturated fatty acids (PUFA), separated as methyl esters (ME). PUFA-ME purified included methyl esters of docosahexaenoic acid (DHA; 22:6(n-3)), eicosapentaenoic acid (EPA; 20:5(n-3)) and the unusual very long-chain (C(28)) highly unsaturated fatty acid (VLC-HUFA), octacosaoctaenoic acid [28:8(n-3)(4, 7, 10, 13, 16, 19, 22, 25)] from the marine dinoflagellate Scrippsiella sp. CS-295/c. Other PUFA purified from various microalgae using this RP-HPLC method to greater than 95% purity included 16:3(n-4), 16:4(n-3), 16:4(n-1) and 18:5(n-3). The number of injections required was variable and depended on the abundance of the desired PUFA-ME, and resolution from closely eluting PUFA-ME, which determined the maximum loading. The purity of these fatty acids was determined by electron impact (EI) GC-MS and the chain length and location of double bonds was determined by EI GC-MS of 4,4-dimethyl oxazoline (DMOX) derivatives formed using a low temperature method. Advantages over silver-ion HPLC for purifying PUFA-ME is that separation occurs according to chain length as well as degree of unsaturation enabling separation of PUFA-ME with the same degree of unsaturation but different chain length (i.e. between 18:5(n-3) and 20:5(n-3)). In addition, PUFA-ME are not strongly adsorbed, but elute earlier than their more saturated corresponding FAME of the same chain length. This method is robust, simple, and requires only a short re-equilibration time. It is a useful tool for preparing milligram quantities of pure PUFA-ME for bioactive screening (as free fatty acids), although many multiple injections may be required for minor PUFA

Inhibition of N-methyl-D-aspartate receptors increases paraoxon-induced apoptosis in cultured neurons

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

Wu Xuan; Tian Feng; Okagaki, Peter

2005-10-01

Organophosphorus (OP) compounds, used as insecticides and chemical warfare agents, are potent neurotoxins. We examined the neurotoxic effect of paraoxon (O,O-diethyl O-p-nitrophenyl phosphate), an organophosphate compound, and the role of NMDA receptors as a mechanism of action in cultured cerebellar granule cells. Paraoxon is neurotoxic to cultured rat cerebellar granule cells in a time- and concentration-dependent manner. Cerebellar granule cells are less sensitive to the neurotoxic effects of paraoxon on day in vitro (DIV) 4 than neurons treated on DIV 8. Surprisingly, the N-methyl-D-aspartate (NMDA) receptor antagonist, MK-801, enhances paraoxon-mediated neurotoxicity suggesting that NMDA receptors may play a protective role.more » Pretreatment with a subtoxic concentration of N-methyl-D-aspartate (NMDA) [100 {mu}M] protects about 40% of the vulnerable neurons that would otherwise die from paraoxon-induced neurotoxicity. Moreover, addition of a neuroprotective concentration of NMDA 3 h after treatment with paraoxon provides the same level of protection. Because paraoxon-mediated neuronal cell death is time-dependent, we hypothesized that apoptosis may be involved. Paraoxon increases apoptosis about 10-fold compared to basal levels. The broad-spectrum caspase inhibitor (Boc-D-FMK) and the caspase-9-specific inhibitor (Z-LEHD-FMK) protect against paraoxon-mediated apoptosis, paraoxon-stimulated caspase-3 activity and neuronal cell death. MK-801 increases, whereas NMDA blocks paraoxon-induced apoptosis and paraoxon-stimulated caspase-3 activity. These results suggest that activation of NMDA receptors protect neurons against paraoxon-induced neurotoxicity by blocking apoptosis initiated by paraoxon.« less

Effects of Dietary Xanthophylls, Canthaxanthin and Astaxanthin on N-Methyl-N-nitrosourea-induced Rat Mammary Carcinogenesis.

PubMed

Yuri, Takashi; Yoshizawa, Katsuhiko; Emoto, Yuko; Kinoshita, Yuichi; Yuki, Michiko; Tsubura, Airo

Natural xanthophylls, canthaxanthin and astaxanthin are known to exhibit anticancer activity. However, the dietary effects of canthaxanthin and astaxanthin on N-methyl-N-nitrosourea (MNU)-induced mammary cancer remain controversial, and their mechanisms of action have not been clearly identified. Three-week-old female Sprague-Dawley rats were fed a xanthophyll-free (basal diet) diet or experimental diets containing canthaxanthin or astaxanthin (0.04% and 0.4%) for 5 weeks (until 8 weeks of age), after which all rats were provided the basal diet (n=15 each). Rats were administered MNU at 6 weeks of age, and the incidence of mammary tumors at 20 weeks of age was compared. The expression of adiponectin in mammary adipose tissues taken at 7 weeks of age was also compared. Compared to the basal diet group, the 0.4% (but not the 0.04%) astaxanthin diet significantly reduced the incidence of palpable mammary carcinoma (92% vs. 42%; p<0.05), while the low and high canthaxanthin diets produced no significant inhibition. Adiponectin immunoblotting showed significantly higher expression in the 0.4% astaxanthin diet group, while the other groups were similar to the basal diet group. High concentrations of astaxanthin suppress MNU-induced mammary carcinoma. Changes in adiponectin may be involved in the mechanism of action. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Synthesis of water-soluble polyamine derivatives effective as N-methyl-D-aspartate receptor antagonists.

PubMed

Masuko, Takashi; Yoshida, Shuhei; Metori, Koichi; Kizawa, Yasuo; Kusama, Tadashi; Miyake, Muneharu

2010-06-01

The novel water-soluble N-methyl-D-aspartate (NMDA) receptor antagonists, N-{4-[4-(4-Guanidinobutylamino)butylamino]butyl}-p-toluenesulfonamide trihydrochloride (1a, TsHSPMG), N-{4-[4-(4-Guanidinobutylamino)butylamino]butyl}butane-1-sulfonamide trihydrochloride (1b, BsHSPMG), N-{3-[4-(3-Guanidinopropylamino)butylamino]propyl}-p-toluenesulfonamide trihydrochroride (2a, TsSPMG) and N-{3-[4-(3-Guanidinopropylamino)butylamino]propyl}butane-1-sulfonamide trihydrochroride (2b, BsSPMG), were synthesized, and the effects of these polyamine derivatives on NMDA receptors were studied using voltage-clamp recordings of recombinant NMDA receptors expressed in Xenopus oocytes. Although spermine potentiates 153% and 310% of NMDA (NR1A/NR2B) receptors in the presence of saturated and unsaturated glycine, respectively, all the novel polyamine derivatives, TsHSPMG (1a), BsHSPMG (1b), TsSPMG (2a) and BsSPMG (2b), significantly inhibited NR1A/NR2B receptors in both conditions. The degree of NMDA receptor inhibition by TsHSPMG (1a) and BsHSPMG (1b) was stronger than that by TsSPMG (2a) and BsSPMG (2b).

Cocrystals of 6-methyl-2-thiouracil: presence of the acceptor-donor-acceptor/donor-acceptor-donor synthon.

PubMed

Hützler, Wilhelm Maximilian; Egert, Ernst

2015-03-01

The results of seven cocrystallization experiments of the antithyroid drug 6-methyl-2-thiouracil (MTU), C(5)H(6)N(2)OS, with 2,4-diaminopyrimidine, 2,4,6-triaminopyrimidine and 6-amino-3H-isocytosine (viz. 2,6-diamino-3H-pyrimidin-4-one) are reported. MTU features an ADA (A = acceptor and D = donor) hydrogen-bonding site, while the three coformers show complementary DAD hydrogen-bonding sites and therefore should be capable of forming an ADA/DAD N-H...O/N-H...N/N-H...S synthon with MTU. The experiments yielded one cocrystal and six cocrystal solvates, namely 6-methyl-2-thiouracil-2,4-diaminopyrimidine-1-methylpyrrolidin-2-one (1/1/2), C(5)H(6)N(2)OS·C(4)H(6)N(4)·2C(5)H(9)NO, (I), 6-methyl-2-thiouracil-2,4-diaminopyrimidine (1/1), C(5)H(6)N(2)OS·C(4)H(6)N(4), (II), 6-methyl-2-thiouracil-2,4-diaminopyrimidine-N,N-dimethylacetamide (2/1/2), 2C(5)H(6)N(2)OS·C(4)H(6)N(4)·2C(4)H(9)NO, (III), 6-methyl-2-thiouracil-2,4-diaminopyrimidine-N,N-dimethylformamide (2/1/2), C(5)H(6)N(2)OS·0.5C(4)H(6)N(4)·C(3)H(7)NO, (IV), 2,4,6-triaminopyrimidinium 6-methyl-2-thiouracilate-6-methyl-2-thiouracil-N,N-dimethylformamide (1/1/2), C(4)H(8)N(5)(+)·C(5)H(5)N(2)OS(-)·C(5)H(6)N(2)OS·2C(3)H(7)NO, (V), 6-methyl-2-thiouracil-6-amino-3H-isocytosine-N,N-dimethylformamide (1/1/1), C(5)H(6)N(2)OS·C(4)H(6)N(4)O·C(3)H(7)NO, (VI), and 6-methyl-2-thiouracil-6-amino-3H-isocytosine-dimethyl sulfoxide (1/1/1), C(5)H(6)N(2)OS·C(4)H(6)N(4)O·C(2)H(6)OS, (VII). Whereas in cocrystal (I) an R(2)(2)(8) interaction similar to the Watson-Crick adenine/uracil base pair is formed and a two-dimensional hydrogen-bonding network is observed, the cocrystals (II)-(VII) contain the triply hydrogen-bonded ADA/DAD N-H...O/N-H...N/N-H...S synthon and show a one-dimensional hydrogen-bonding network. Although 2,4-diaminopyrimidine possesses only one DAD hydrogen-bonding site, it is, due to orientational disorder, triply connected to two MTU molecules in (III) and (IV).

Blockade of N-methyl-D-aspartate Receptors May Protect against Ischemic Damage in the Brain

NASA Astrophysics Data System (ADS)

Simon, R. P.; Swan, J. H.; Griffiths, T.; Meldrum, B. S.

1984-11-01

In rats ischemia of the forebrain induced by a 30-minute occlusion of the carotid artery, followed by 120 minutes of arterial reperfusion, produced ischemic lesions of selectively vulnerable pyramidal cells in both hippocampi. Focal microinfusion into the dorsal hippocampus of 2-amino-7-phosphonoheptanoic acid, an antagonist of excitation at the N-methyl-d-asparate-preferring receptor, before ischemia was induced protected against the development of ischemic damage. It is proposed that excitatory neurotransmission plays an important role in selective neuronal loss due to cerebral ischemia.

Looking for prosocial genes: ITRAQ analysis of proteins involved in MDMA-induced sociability in mice.

PubMed

Kuteykin-Teplyakov, Konstantin; Maldonado, Rafael

2014-11-01

Social behavior plays a fundamental role in life of many animal species, allowing the interaction between individuals and sharing of experiences, needs, and goals across them. In humans, some neuropsychiatric diseases, including anxiety, posttraumatic stress disorder and autism spectrum disorders, are often characterized by impaired sociability. Here we report that N-Methyl-3,4-methylenedioxyamphetamine (MDMA, "Ecstasy") at low dose (3mg/kg) has differential effects on mouse social behavior. In some animals, MDMA promotes sociability without hyperlocomotion, whereas in other mice it elevates locomotor activity without affecting sociability. Both WAY-100635, a selective antagonist of 5-HT1A receptor, and L-368899, a selective oxytocin receptor antagonist, abolish prosocial effects of MDMA. Differential quantitative analysis of brain proteome by isobaric tag for relative and absolute quantification technology (iTRAQ) revealed 21 specific proteins that were highly correlated with sociability, and allowed to distinguish between entactogenic prosocial and hyperlocomotor effects of MDMA on proteome level. Our data suggest particular relevance of neurotransmission mediated by GABA B receptor, as well as proteins involved in energy maintenance for MDMA-induced sociability. Functional association network for differentially expressed proteins in cerebral cortex, hippocampus and amygdala were identified. These results provide new information for understanding the neurobiological substrate of sociability and may help to discover new therapeutic approaches to modulate social behavior in patients suffering from social fear and low sociability. Copyright © 2014 Elsevier B.V. and ECNP. All rights reserved.

Chloromethane to olefins over H-SAPO-34: Probing the hydrocarbon pool mechanism

DOE PAGES

Fickel, Dustin W.; Sabnis, Kaiwalya D.; Li, Luanyi; ...

2016-09-09

In this paper, by means of in situ FTIR and ex situ 13C NMR studies, the initial periods of the chloromethane-to-olefins (CTO) reaction over SAPO-34 were probed in order to investigate the activation period of the reaction and to elucidate the formation of the catalyst active site. A methylated benzene species has been observed to form during the initial activation period of the reaction, and a direct positive correlation was constructed between the formation of this species and the catalytic activity. The data thus indicate that these methylated benzene species contribute to the formation of active sites within SAPO-34 formore » the CTO reaction. This is the first known report identifying a direct semi-quantitative correlation between the catalyst activity and growth of a methylated benzene active species, during the activation period of the chloromethane to olefins reaction. Finally, the findings here in correspond well to those reported for the methanol to olefins reaction, suggesting that a similar ‘hydrocarbon pool’ mechanism may be responsible for the formation of light olefins in CTO chemistry as well.« less

DNA methylation pattern of apoptosis-related genes in ameloblastoma.

PubMed

Costa, Sfs; Pereira, N B; Pereira, Kma; Campos, K; de Castro, W H; Diniz, M G; Gomes, C C; Gomez, R S

2017-09-01

DNA methylation is an important mechanism of gene control expression, and it has been poorly addressed in odontogenic tumours. On this basis, we aimed to assess the methylation pattern of 22 apoptosis-related genes in solid ameloblastomas. Ameloblastoma fresh samples (n = 10) and dental follicles (n = 8) were included in the study. The percentage fraction of methylated and unmethylated DNA promoter of 22 apoptosis-related genes was determined using enzymatic restriction digestion and quantitative real-time PCR (qPCR) array. The relative expressions of the genes that showed the most discrepant methylation profile between tumours and controls were analysed by reverse-transcription quantitative PCR (RT-qPCR). Lower methylation percentages of TNFRSF25 (47.2%) and BCL2L11 (33.2%) were observed in ameloblastomas compared with dental follicles (79.3% and 59.5%, respectively). The RT-qPCR analysis showed increased expression of BCL2L11 in ameloblastomas compared with dental follicles, in agreement with the methylation analysis results, while there was no difference between the expression levels of TNFRSF25 between both groups. On the basis of our results, the transcription of the apoptosis-related gene BCL2L11 is possibly regulated by promoter DNA methylation in ameloblastoma. The biological significance of this finding in ameloblastoma pathobiology remains to be clarified. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

5-Bromo-2-methyl­pyridine N-oxide

PubMed Central

Liu, Bo-Nian; Tang, Shi-Gui; Li, Hao-Yuan; Xu, Ye-Ming; Guo, Cheng

2008-01-01

In the mol­ecule of the title compound, C6H6BrNO, the methyl C and oxide O atoms lie in the pyridine ring plane, while the Br atom is displaced by 0.103 (3) Å. In the crystal structure, inter­molecular C—H⋯O hydrogen bonds link the mol­ecules into centrosymmetric dimers. PMID:21202579

[Methylation of selected tumor-supressor genes in benign and malignant ovarian tumors].

PubMed

Cul'bová, M; Lasabová, Z; Stanclová, A; Tilandyová, P; Zúbor, P; Fiolka, R; Danko, J; Visnovský, J

2011-09-01

To evaluate the usefullness of examination of methylation status of selected tumor-supressor genes in early diagnosis of ovarian cancer. Prospective clinical study. Department of Gynecology and Obstetrics, Department of Molecular Biology, Jessenius Medical Faculty, Commenius University, Martin, Slovak Republic. In this study we analyzed hypermethylation of 5 genes RASSF1A, GSTP, E-cadherin, p16 and APC in ovarian tumor samples from 34 patients - 13 patients with epithelial ovarian cancer, 2 patients with border-line ovarian tumors, 12 patients with benign lesions of ovaries and 7 patients with healthy ovarian tissue. The methylation status of promoter region of tumor-supressor genes was determined by Methylation Specific Polymerase Chain Reaction (MSP) using a nested two-step approach with bisulfite modified DNA template and specific primers. Gene methylation analysis revealed hypermethylation of gene RASSF1A (46%) and GSTP (8%) only in malignant ovarian tissue samples. Ecad, p16 and APC genes were methylated both in maignant and benign tissue samples. Methylation positivity in observed genes was present independently to all clinical stages of ovarian cancer and to tumor grades. However, there was observed a trend of increased number and selective involvement of methylated genes with increasing disease stages. Furthermore, there was no association between positive methylation status and histological subtypes of ovarian carcinomas. RASSF1A and GSTP promoter methylation positivity is associated with ovarian cancer. The revealed gene-selective methylation positivity and the increased number of methylated genes with advancing disease stages could be considered as a useful molecular marker for early detection of ovarian cancer. However, there is need to find diagnostic approach of specifically and frequently methylated genes to determining a methylation phenotype for early detection of ovarian malignancies.

Methylation matters

PubMed Central

Costello, J.; Plass, C.

2001-01-01

DNA methylation is not just for basic scientists any more. There is a growing awareness in the medical field that having the correct pattern of genomic methylation is essential for healthy cells and organs. If methylation patterns are not properly established or maintained, disorders as diverse as mental retardation, immune deficiency, and sporadic or inherited cancers may follow. Through inappropriate silencing of growth regulating genes and simultaneous destabilisation of whole chromosomes, methylation defects help create a chaotic state from which cancer cells evolve. Methylation defects are present in cells before the onset of obvious malignancy and therefore cannot be explained simply as a consequence of a deregulated cancer cell. Researchers are now able to detect with exquisite sensitivity the cells harbouring methylation defects, sometimes months or years before the time when cancer is clinically detectable. Furthermore, aberrant methylation of specific genes has been directly linked with the tumour response to chemotherapy and patient survival. Advances in our ability to observe the methylation status of the entire cancer cell genome have led us to the unmistakable conclusion that methylation abnormalities are far more prevalent than expected. This methylomics approach permits the integration of an ever growing repertoire of methylation defects with the genetic alterations catalogued from tumours over the past two decades. Here we discuss the current knowledge of DNA methylation in normal cells and disease states, and how this relates directly to our current understanding of the mechanisms by which tumours arise.


Keywords: methylation; cancer PMID:11333864

Trans-ethyl methyl ether, the struggle for the detection of a complex molecule in hot cores

NASA Astrophysics Data System (ADS)

Fuchs, G. W.; Fuchs, U.; Giesen, T. F.; Wyrowski, F.

Many large and complex molecules of prebiotic importance have been found as constituents of interstellar clouds but their detection remains difficult and sometimes doubtful (Snyder et al. 2005). The complex spectrum of trans-ethyl methyl ether (EME) has been investigated in the laboratory (Fuchs et al. 2003) up to 350 GHz and is now known with high frequency precision, see Figure 1. In this work we present an extensive search for EME towards G34.26, NGC6334(I), Orion KL, SgrB2(N) and W51e2 in the 1 to 3 mm wavelength region. These sources have previously been shown to have a rich chemistry of complex molecules. The IRAM 30m telescope at Pico Veleta, Spain and the SEST 15m radio telescope in La Silla, Chile have been used for the observations. We looked at 5 - 11 frequency bands where EME has strong transitions. All sources were examined using long integration times up to 220 min (on+off), elevations greater 40◦ and under good weather conditions. For our analysis of the data we used the method of rotational-temperature-diagrams but also the myXCLASS (written by Peter Schilke) extension program to the GILDAS (Grenoble Image and Line Data Analysis Software) software which enabled us to simulate spectra of several molecules including their linewidth and intensities at the same time, see Figure 2. With this program a consistency check of molecular abundances and overall composition is possible even in dense spectra with many overlapping lines. The effect of the source size on the measured intensities has been considered and cross checks with other important molecules such as methanol, ethanol and di-methyl ether have been performed. Charnley et al. (2001) assigned one line in W51 e1/e2 and one line in Orion KL at 160.1 GHz, as well as a line in SgrB2(N) at 79.6 GHz to trans-ethyl methyl ether. From their isolated measurements, the column density of EME was estimated to be in the range 1014-1015 cm-2 in Sgr B2(N) corresponding to a fractional abundance of 10

Alternation of histone and DNA methylation in human atherosclerotic carotid plaques.

PubMed

Greißel, A; Culmes, M; Napieralski, R; Wagner, E; Gebhard, H; Schmitt, M; Zimmermann, A; Eckstein, H-H; Zernecke, A; Pelisek, J

2015-08-01

Little is known about epigenetics and its possible role in atherosclerosis. We here analysed histone and DNA methylation and the expression of corresponding methyltransferases in early and advanced human atherosclerotic carotid lesions in comparison to healthy carotid arteries. Western Blotting was performed on carotid plaques from our biobank with early (n=60) or advanced (n=60) stages of atherosclerosis and healthy carotid arteries (n=12) to analyse di-methylation patterns of histone H3 at positions K4, K9 and K27. In atherosclerotic lesions, di-methylation of H3K4 was unaltered and that of H3K9 and H3K27 significantly decreased compared to control arteries. Immunohistochemistry revealed an increased appearance of di-methylated H3K4 in smooth muscle cells (SMCs), a decreased expression of di-methylated H3K9 in SMCs and inflammatory cells, and reduced di-methylated H3K27 in inflammatory cells in advanced versus early atherosclerosis. Expression of corresponding histone methyltransferases MLL2 and G9a was increased in advanced versus early atherosclerosis. Genomic DNA hypomethylation, as determined by PCR for methylated LINE1 and SAT-alpha, was observed in early and advanced plaques compared to control arteries and in cell-free serum of patients with high-grade carotid stenosis compared to healthy volunteers. In contrast, no differences in DNA methylation were observed in blood cells. Expression of DNA-methyltransferase DNMT1 was reduced in atherosclerotic plaques versus controls, DNMT3A was undetectable, and DNMT3B not altered. DNA-demethylase TET1 was increased in atherosclerosisc plaques. The extent of histone and DNA methylation and expression of some corresponding methyltransferases are significantly altered in atherosclerosis, suggesting a possible contribution of epigenetics in disease development.

Histone arginine methylations: their roles in chromatin dynamics and transcriptional regulation

PubMed Central

LITT, Michael; QIU, Yi; HUANG, Suming

2017-01-01

Synopsis PRMTs (protein arginine N-methyltransferases) specifically modify the arginine residues of key cellular and nuclear proteins as well as histone substrates. Like lysine methylation, transcriptional repression or activation is dependent upon the site and type of arginine methylation on histone tails. Recent discoveries imply that histone arginine methylation is an important modulator of dynamic chromatin regulation and transcriptional controls. However, under the shadow of lysine methylation, the roles of histone arginine methylation have been under-explored. The present review focuses on the roles of histone arginine methylation in the regulation of gene expression, and the interplays between histone arginine methylation, histone acetylation, lysine methylation and chromatin remodelling factors. In addition, we discuss the dynamic regulation of arginine methylation by arginine demethylases, and how dysregulation of PRMTs and their activities are linked to human diseases such as cancer. PMID:19220199

Measurement of the methyl cyanide E/A ratio in TMC-1

NASA Technical Reports Server (NTRS)

Minh, Y. C.; Irvine, W. M.; Ohishi, M.; Ishikawa, S.; Saito, S.; Kaifu, N.

1993-01-01

We have observed the methyl cyanide (CH3CN) J = 2-1 K = 0 and 1 transitions toward the cyanopolyyne peak of TMC-1 and have derived an E/A (ortho/para)abundance ratio N(E)/N(A) = 0.75 +/- 0.10. The total methyl cyanide column density is N(total) = 5 x 10 exp 12/sq cm toward TMC-1, in agreement with earlier results from the J = 1-0 lines.

MeT-DB V2.0: elucidating context-specific functions of N6-methyl-adenosine methyltranscriptome

PubMed Central

Liu, Hui; Wang, Huaizhi; Wei, Zhen; Zhang, Songyao; Hua, Gang; Zhang, Shao-Wu; Zhang, Lin; Gao, Shou-Jiang

2018-01-01

Abstract Methyltranscriptome is an exciting new area that studies the mechanisms and functions of methylation in transcripts. A knowledge base with the systematic collection and curation of context specific transcriptome-wide methylations is critical for elucidating their biological functions as well as for developing bioinformatics tools. Since its inception in 2014, the Met-DB (Liu, H., Flores, M.A., Meng, J., Zhang, L., Zhao, X., Rao, M.K., Chen, Y. and Huang, Y. (2015) MeT-DB: a database of transcriptome methylation in mammalian cells. Nucleic Acids Res., 43, D197–D203), has become an important resource for methyltranscriptome, especially in the N6-methyl-adenosine (m6A) research community. Here, we report Met-DB v2.0, the significantly improved second version of Met-DB, which is entirely redesigned to focus more on elucidating context-specific m6A functions. Met-DB v2.0 has a major increase in context-specific m6A peaks and single-base sites predicted from 185 samples for 7 species from 26 independent studies. Moreover, it is also integrated with a new database for targets of m6A readers, erasers and writers and expanded with more collections of functional data. The redesigned Met-DB v2.0 web interface and genome browser provide more friendly, powerful, and informative ways to query and visualize the data. More importantly, MeT-DB v2.0 offers for the first time a series of tools specifically designed for understanding m6A functions. Met-DB V2.0 will be a valuable resource for m6A methyltranscriptome research. The Met-DB V2.0 database is available at http://compgenomics.utsa.edu/MeTDB/ and http://www.xjtlu.edu.cn/metdb2. PMID:29126312

tRNA1Ser(G34) with the anticodon GGA can recognize not only UCC and UCU codons but also UCA and UCG codons.

PubMed

Yamada, Yuko; Matsugi, Jitsuhiro; Ishikura, Hisayuki

2003-04-15

The tRNA1Ser (anticodon VGA, V=uridin-5-oxyacetic acid) is essential for translation of the UCA codon in Escherichia coli. Here, we studied the translational abilities of serine tRNA derivatives, which have different bases from wild type at the first positions of their anticodons, using synthetic mRNAs containing the UCN (N=A, G, C, or U) codon. The tRNA1Ser(G34) having the anticodon GGA was able to read not only UCC and UCU codons but also UCA and UCG codons. This means that the formation of G-A or G-G pair allowed at the wobble position and these base pairs are noncanonical. The translational efficiency of the tRNA1Ser(G34) for UCA or UCG codon depends on the 2'-O-methylation of the C32 (Cm). The 2'-O-methylation of C32 may give rise to the space necessary for G-A or G-G base pair formation between the first position of anticodon and the third position of codon.

N-terminally truncated GADD34 proteins are convenient translation enhancers in a human cell-derived in vitro protein synthesis system.

PubMed

Mikami, Satoshi; Kobayashi, Tominari; Machida, Kodai; Masutani, Mamiko; Yokoyama, Shigeyuki; Imataka, Hiroaki

2010-07-01

Human cell-derived in vitro protein synthesis systems are useful for the production of recombinant proteins. Productivity can be increased by supplementation with GADD34, a protein that is difficult to express in and purify from E. coli. Deletion of the N-terminal 120 or 240 amino acids of GADD34 improves recovery of this protein from E. coli without compromising its ability to boost protein synthesis in an in vitro protein synthesis system. The use of N-terminally truncated GADD34 proteins in place of full-length GADD34 should improve the utility of human cell-based cell-free protein synthesis systems.

The molecular core in G34.3 + 0.2 - Millimeter interferometric observations of HCO(+), H(C-13)N, H(C-15)N, and SO

NASA Technical Reports Server (NTRS)

Carral, Patricia; Welch, William J.

1992-01-01

This study presents high-resolution observations of the molecular core in the star-forming region G34.3 + 0.2. Maps at 6-arcsec resolution of emission and absorption of the J = 1 - 0 transitions of HCO(+), H (C-13)N, H(C-15)N, and of the 2(2) - 1(1) transition of SO were obtained in addition to a map of the 3.4-mm continuum emission from the compact H II component. The HCL(+) emission toward G34.3 + 0.2 traces a warm molecular core about 0.9 pc in size. Emission from H (C-13)N is detected over about 0.3 pc. The cometary H II region lies near the edge of the molecular core. The blueshift of the radio recombination lines with respect to the molecular emission suggests that gas from the H II region is accelerated in a champagne flow caused by a steep gradient in the ambient gas density.

Studies on the Mechanism of Action of Hydrazine-Induced Methylation of DNA Guanne

DTIC Science & Technology

1984-10-03

potent methylating agent , diazomethane (-CH -N+-N). Several in vivo studies were carried out to determine the role of aldehydes in the alkylation of DNA...methylating agent available to interact with DNA. If such a mechanism occurs, it may explain why disulfiram appears to inhibit the alkylation of DNA...a much slower/poorer alkylating agent for DNA. Effect of the 1-Carbon Pool on DNA Methylation in Hydrazine Toxicity: In Vitro In vitro studies were

N-demethylation of N-methyl-4-aminoantipyrine, the main metabolite of metamizole.

PubMed

Bachmann, Fabio; Duthaler, Urs; Rudin, Deborah; Krähenbühl, Stephan; Haschke, Manuel

2018-05-08

Metamizole is an old analgesic used frequently in some countries. Active metabolites of metamizole are the non-enzymatically generated N-methyl-4-aminoantipyrine (4-MAA) and its demethylation product 4-aminoantipyrine (4-AA). Previous studies suggested that 4-MAA demethylation can be performed by hepatic cytochrome P450 (CYP) 3A4, but the possible contribution of other CYPs remains unclear. Using human liver microsomes (HLM), liver homogenate and HepaRG cells, we could confirm 4-MAA demethylation by CYPs. Based on CYP induction (HepaRG cells) and CYP inhibition (HLM) we could identify CYP2B6, 2C8, 2C9 and 3A4 as major contributors to 4-MAA demethylation. The 4-MAA demethylation rate by HLM was 280 pmol/mg protein/h, too low to account for in vivo 4-MAA demethylation in humans. Since peroxidases can perform N-demethylation, we investigated horseradish peroxidase and human myeloperoxidase (MPO). Horse radish peroxidase efficiently demethylated 4-MAA, depending on the hydrogen peroxide concentration. This was also true for MPO; this reaction was saturable with a K m of 22.5 μM and a maximal velocity of 14 nmol/min/mg protein. Calculation of the entire body MPO capacity revealed that the demethylation capacity by granulocyte/granulocyte precursors was approximately 600 times higher than the liver capacity and could account for 4-MAA demethylation in humans. 4-MAA demethylation could also be demonstrated in MPO-expressing granulocyte precursor cells (HL-60). In conclusion, 4-MAA can be demethylated in the liver by several CYPs, but hepatic metabolism cannot fully explain 4-MAA demethylation in humans. The current study suggests that the major part of 4-MAA is demethylated by circulating granulocytes and granulocyte precursors in bone marrow. Copyright © 2018 Elsevier B.V. All rights reserved.

Identification of methylated genes in salivary gland adenoid cystic carcinoma xenografts using global demethylation and methylation microarray screening

PubMed Central

LING, SHIZHANG; RETTIG, ELENI M.; TAN, MARIETTA; CHANG, XIAOFEI; WANG, ZHIMING; BRAIT, MARIANA; BISHOP, JUSTIN A.; FERTIG, ELANA J.; CONSIDINE, MICHAEL; WICK, MICHAEL J.; HA, PATRICK K.

2016-01-01

Salivary gland adenoid cystic carcinoma (ACC) is a rare head and neck malignancy without molecular biomarkers that can be used to predict the chemotherapeutic response or prognosis of ACC. The regulation of gene expression of oncogenes and tumor suppressor genes (TSGs) through DNA promoter methylation may play a role in the carcinogenesis of ACC. To identify differentially methylated genes in ACC, a global demethylating agent, 5-aza-2′-deoxycytidine (5-AZA) was utilized to unmask putative TSG silencing in ACC xenograft models in mice. Fresh xenografts were passaged, implanted in triplicate in mice that were treated with 5-AZA daily for 28 days. These xenografts were then evaluated for genome-wide DNA methylation patterns using the Illumina Infinium HumanMethylation27 BeadChip array. Validation of the 32 candidate genes was performed by bisulfite sequencing (BS-seq) in a separate cohort of 6 ACC primary tumors and 6 normal control salivary gland tissues. Hypermethylation was identified in the HCN2 gene promoter in all 6 control tissues, but hypomethylation was found in all 6 ACC tumor tissues. Quantitative validation of HCN2 promoter methylation level in the region detected by BS-seq was performed in a larger cohort of primary tumors (n=32) confirming significant HCN2 hypomethylation in ACCs compared with normal samples (n=10; P=0.04). HCN2 immunohistochemical staining was performed on an ACC tissue microarray. HCN2 staining intensity and H-score, but not percentage of the positively stained cells, were significantly stronger in normal tissues than those of ACC tissues. With our novel screening and sequencing methods, we identified several gene candidates that were methylated. The most significant of these genes, HCN2, was actually hypomethylated in tumors. However, promoter methylation status does not appear to be a major determinant of HCN2 expression in normal and ACC tissues. HCN2 hypomethylation is a biomarker of ACC and may play an important role in the

Determination of 5-hydroxy-N-methyl-2-pyrrolidone and 2-hydroxy-N-methylsuccinimide in human plasma and urine using liquid chromatography-electrospray tandem mass spectrometry.

PubMed

Carnerup, M A; Akesson, B; Jönsson, B A

2001-09-15

A method for simultaneous determination of 5-hydroxy-N-methyl-2-pyrrolidone (5-HNMP) and 2-hydroxy-N-methylsuccinimide (2-HMSI) was developed. These compounds are metabolites from N-methyl-2-pyrrolidone (NMP), a powerful and widely used organic solvent. 5-HNMP and 2-HMSI were purified from plasma and urine by solid-phase extraction using Isolute ENV+ columns, and analysed by liquid chromatography coupled to a mass spectrometer fitted with an atmospheric pressure turbo ion spray ionisation interface in the positive ion mode. The method was validated for plasma and urine concentrations from 0.12 to 25 microg/ml. The recoveries for 5-HNMP and 2-HMSI in plasma were 99 and 98%, respectively, and in urine 111 and 106%, respectively. For 5-HNMP and 2-HMSI, the within-day precision in plasma was 1-4 and 3-6%, respectively, and in urine 2-12 and 3-10%, respectively. The corresponding data for the between-day precision was 5 and 3-6%, respectively, and 4-6 and 7-8%, respectively. The detection limit for 5-HNMP was 4 ng/ml in plasma and 120 ng/ml in urine. For 2-HMSI, it was 5 ng/ml in plasma and 85 ng/ml in urine. The method is applicable for analysis of plasma and urine samples from workers exposed to NMP.

Aberrant Methylation-Mediated Suppression of APAF1 in Myelodysplastic Syndrome.

PubMed

Zaker, Farhad; Nasiri, Nahid; Amirizadeh, Naser; Razavi, Seyed Mohsen; Yaghmaie, Marjan; Teimoori-Toolabi, Ladan; Maleki, Ali; Bakhshayesh, Masoumeh

2017-04-01

Background: Myelodysplastic syndromes (MDSs) include a diverse group of clonal bone marrow disorders characterized by ineffective hematopoiesis and pancytopenia. It was found that down regulation of APAF1, a putative tumor suppressor gene (TSG), leads to resistance to chemotherapy and disease development in some cancers. In this study, we investigated the relation of APAF1 methylation status with its expression and clinicopathological factors in myelodysplastic syndrome (MDS) patients. Materials and Methods: Methylation Sensitive-High Resolution Melting Curve Analysis (MS-HRM) was employed in studying the methylation of CpG islands in the APAF1promoter region in MDS. Gene expression was analyzed by using real time RT-PCR. Results: 42.6% of patient samples were methylated in promoter region of APAF1analyzed, while methylation of the gene was not seen in controls (P<0.05). Methylation of APAF1was significantly associated with the suppression of its mRNA expression (P=0.00). The methylation status of APAF1in advanced-stage MDS patients (80%) was significantly higher than that of the early-stage MDS patients (28.2%) (P=0.001). The difference in frequency of hypermethylatedAPAF1 gene was significant between good (37.5%) and poor (85.71%) cytogenetic risk groups (P=0.043). In addition, a higher frequency of APAF1hypermethylation was observed in higher-risk MDS group (69.2%) compared to lower-risk MDS group (34.14%) (P=0.026). Conclusion: Our study indicated that APAF1hypermethylation in MDS was associated to high-risk disease classified according to the IPSS, WHO and cytogenetic risk.

DNA methylation markers for diagnosis and prognosis of common cancers

PubMed Central

Hao, Xiaoke; Luo, Huiyan; Krawczyk, Michal; Wei, Wei; Wang, Wenqiu; Wang, Juan; Flagg, Ken; Hou, Jiayi; Zhang, Heng; Yi, Shaohua; Jafari, Maryam; Lin, Danni; Chung, Christopher; Caughey, Bennett A.; Li, Gen; Dhar, Debanjan; Shi, William; Zheng, Lianghong; Hou, Rui; Zhu, Jie; Zhao, Liang; Fu, Xin; Zhang, Edward; Zhang, Charlotte; Zhu, Jian-Kang; Karin, Michael; Xu, Rui-Hua; Zhang, Kang

2017-01-01

The ability to identify a specific cancer using minimally invasive biopsy holds great promise for improving the diagnosis, treatment selection, and prediction of prognosis in cancer. Using whole-genome methylation data from The Cancer Genome Atlas (TCGA) and machine learning methods, we evaluated the utility of DNA methylation for differentiating tumor tissue and normal tissue for four common cancers (breast, colon, liver, and lung). We identified cancer markers in a training cohort of 1,619 tumor samples and 173 matched adjacent normal tissue samples. We replicated our findings in a separate TCGA cohort of 791 tumor samples and 93 matched adjacent normal tissue samples, as well as an independent Chinese cohort of 394 tumor samples and 324 matched adjacent normal tissue samples. The DNA methylation analysis could predict cancer versus normal tissue with more than 95% accuracy in these three cohorts, demonstrating accuracy comparable to typical diagnostic methods. This analysis also correctly identified 29 of 30 colorectal cancer metastases to the liver and 32 of 34 colorectal cancer metastases to the lung. We also found that methylation patterns can predict prognosis and survival. We correlated differential methylation of CpG sites predictive of cancer with expression of associated genes known to be important in cancer biology, showing decreased expression with increased methylation, as expected. We verified gene expression profiles in a mouse model of hepatocellular carcinoma. Taken together, these findings demonstrate the utility of methylation biomarkers for the molecular characterization of cancer, with implications for diagnosis and prognosis. PMID:28652331

RlmCD-mediated U747 methylation promotes efficient G748 methylation by methyltransferase RlmAII in 23S rRNA in Streptococcus pneumoniae; interplay between two rRNA methylations responsible for telithromycin susceptibility.

PubMed

Shoji, Tatsuma; Takaya, Akiko; Sato, Yoshiharu; Kimura, Satoshi; Suzuki, Tsutomu; Yamamoto, Tomoko

2015-10-15

Adenine at position 752 in a loop of helix 35 from positions 745 to 752 in domain II of 23S rRNA is involved in binding to the ribosome of telithromycin (TEL), a member of ketolides. Methylation of guanine at position 748 by the intrinsic methyltransferase RlmA(II) enhances binding of telithromycin (TEL) to A752 in Streptococcus pneumoniae. We have found that another intrinsic methylation of the adjacent uridine at position 747 enhances G748 methylation by RlmA(II), rendering TEL susceptibility. U747 and another nucleotide, U1939, were methylated by the dual-specific methyltransferase RlmCD encoded by SP_1029 in S. pneumoniae. Inactivation of RlmCD reduced N1-methylated level of G748 by RlmA(II) in vivo, leading to TEL resistance when the nucleotide A2058, located in domain V of 23S rRNA, was dimethylated by the dimethyltransferase Erm(B). In vitro methylation of rRNA showed that RlmA(II) activity was significantly enhanced by RlmCD-mediated pre-methylation of 23S rRNA. These results suggest that RlmCD-mediated U747 methylation promotes efficient G748 methylation by RlmA(II), thereby facilitating TEL binding to the ribosome. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

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

PubMed

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

2011-06-01

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

Attenuation by genistein of sodium-chloride-enhanced gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

PubMed

Tatsuta, M; Iishi, H; Baba, M; Yano, H; Uehara, H; Nakaizumi, A

1999-01-29

The effects of prolonged administration of genistein, a tyrosine-kinase inhibitor, on sodium-chloride-enhanced induction of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine, and the labeling and apoptotic indices and vessel counts in the gastric mucosa and gastric cancers, were investigated in Wistar rats. After 25 weeks of the carcinogen treatment, rats were fed chow pellets containing 10% sodium chloride and were given s.c. injections of genistein at dosages of 15 mg/kg or 30 mg/kg body weight every other day. In week 52, the incidence of gastric cancers was significantly greater in rats fed sodium chloride than in untreated control rats. Prolonged administration of genistein at a dosage of 30 mg/kg, but not 15 mg/kg, body weight significantly reduced the incidence of gastric cancers, which was increased by oral treatment with sodium chloride. Genistein at the higher dose significantly decreased the labeling index and vessel counts of the antral mucosa and the gastric cancers (which were increased by treatment with sodium chloride) and significantly increased the apoptotic index of the antral mucosa and the cancers (which was lowered by the treatment with sodium chloride). These findings suggest that genistein attenuates gastric carcinogenesis promoted by sodium chloride, by inducing increased apoptosis and lower cell proliferation and angiogenesis of antral mucosa and gastric cancers.

Low-protein diet promotes sodium chloride-enhanced gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

PubMed

Iishi, H; Tatsuta, M; Baba, M; Hirasawa, R; Sakai, N; Yano, H; Uehara, H; Nakaizumi, A

1999-07-01

Sodium chloride (NaCl) initiates and promotes experimental carcinogenesis in rats. We recently found that a high-protein diet attenuates NaCl-enhanced gastric carcinogenesis in Wistar rats. To investigate the effect of a purified low-protein diet on NaCl-enhanced gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in Wistar rats, rats were fed a purified diet with an equalized caloric content containing 1% or 2% NaCl and 25% casein (normal-protein diet) or 10% casein (low-protein diet) after oral treatment with MNNG for 25 weeks. In week 52, neither 1% nor 2% NaCl had a significant effect on gastric carcinogenesis in rats fed a normal-protein diet. However, oral administration of 2%, but not 1%, NaCl significantly increased the incidence of gastric cancers in rats fed a low-protein diet. Oral administration of 2% NaCl also significantly increased the bromodeoxyuridine (BrdU)-labeling index and the ornithine decarboxylase (ODC) activity and decreased apoptosis of gastric cancers in rats fed a low-protein diet. However, 2% NaCl had no significant effect on these three parameters in rats fed a normal-protein diet. These findings indicate that a low-protein diet enhances the effect of NaCl in gastric carcinogenesis and that this enhancement may be mediated by increased cell proliferation and reduced apoptosis of gastric cancers.

Epigenetic Gene Promoter Methylation at Birth Is Associated With Child’s Later Adiposity

PubMed Central

Godfrey, Keith M.; Sheppard, Allan; Gluckman, Peter D.; Lillycrop, Karen A.; Burdge, Graham C.; McLean, Cameron; Rodford, Joanne; Slater-Jefferies, Joanne L.; Garratt, Emma; Crozier, Sarah R.; Emerald, B. Starling; Gale, Catharine R.; Inskip, Hazel M.; Cooper, Cyrus; Hanson, Mark A.

2011-01-01

OBJECTIVE Fixed genomic variation explains only a small proportion of the risk of adiposity. In animal models, maternal diet alters offspring body composition, accompanied by epigenetic changes in metabolic control genes. Little is known about whether such processes operate in humans. RESEARCH DESIGN AND METHODS Using Sequenom MassARRAY we measured the methylation status of 68 CpGs 5′ from five candidate genes in umbilical cord tissue DNA from healthy neonates. Methylation varied greatly at particular CpGs: for 31 CpGs with median methylation ≥5% and a 5–95% range ≥10%, we related methylation status to maternal pregnancy diet and to child’s adiposity at age 9 years. Replication was sought in a second independent cohort. RESULTS In cohort 1, retinoid X receptor-α (RXRA) chr9:136355885+ and endothelial nitric oxide synthase (eNOS) chr7:150315553+ methylation had independent associations with sex-adjusted childhood fat mass (exponentiated regression coefficient [β] 17% per SD change in methylation [95% CI 4–31], P = 0.009, n = 64, and β = 20% [9–32], P < 0.001, n = 66, respectively) and %fat mass (β = 10% [1–19], P = 0.023, n = 64 and β =12% [4–20], P = 0.002, n = 66, respectively). Regression analyses including sex and neonatal epigenetic marks explained >25% of the variance in childhood adiposity. Higher methylation of RXRA chr9:136355885+, but not of eNOS chr7:150315553+, was associated with lower maternal carbohydrate intake in early pregnancy, previously linked with higher neonatal adiposity in this population. In cohort 2, cord eNOS chr7:150315553+ methylation showed no association with adiposity, but RXRA chr9:136355885+ methylation showed similar associations with fat mass and %fat mass (β = 6% [2–10] and β = 4% [1–7], respectively, both P = 0.002, n = 239). CONCLUSIONS Our findings suggest a substantial component of metabolic disease risk has a prenatal developmental basis. Perinatal epigenetic analysis may have utility in

Antinociceptive effect and mechanism of action of isatin, N-methyl isatin and oxopropyl isatin in mice.

PubMed

Giorno, Thais Biondino Sardella; Silva, Bárbara Vasconcellos da; Pinto, Angelo da Cunha; Fernandes, Patricia Dias

2016-04-15

There has been growing interest in the synthesis of new derivatives from isatin, found in Isatis genus. Our objectives were to characterize the antinociceptive mechanism of action of isatin, N-methyl-isatin (MI) and N-methyl-3-(2-oxopropyl)-3-hydroxy-2-oxindole (MOI). Substances (0.1-10mg/kg, p.o.) were studied in chemical (paw licking induced by formalin, capsaicin or glutamate) or thermal (hot plate) models of nociception. The involvement of several systems was evaluated using different receptor antagonists. All three substances inhibit both phases of formalin-induced licking, increase the area under the curve and MI and MOI have a higher effect than that of morphine (in hot plate). Capsaicin and glutamate-induced licking were also reduced by all three substances. In the hot plate model, the antinociceptive effect of isatin was reduced by naloxone and atropine; naloxone, atropine and L-NAME reduced MI effect while naloxone, atropine, L-NAME, mecamylamine and ondansetron reduced MOI effect. Our results suggest that isatin, MI and MOI: 1) present activity in models of nociception; 2) capsaicin and glutamate receptors seems to participate in the mechanism of action; 3) opioid, cholinergic, serotoninergic, nitrergic and adrenergic systems may be involved, at least in part, in the mechanism of action of some of these substances. Copyright © 2016 Elsevier Inc. All rights reserved.

Molecular recognition at methyl methacrylate/n-butyl acrylate (MMA/nBA) monomer unit boundaries of phospholipids at p-MMA/nBA copolymer surfaces.

PubMed

Yu, Min; Urban, Marek W; Sheng, Yinghong; Leszczynski, Jerzy

2008-09-16

Lipid structural features and their interactions with proteins provide a useful vehicle for further advances in membrane proteins research. To mimic one of potential lipid-protein interactions we synthesized poly(methyl methacrylate/ n-butyl acrylate) (p-MMA/nBA) colloidal particles that were stabilized by phospholipid (PLs). Upon the particle coalescence, PL stratification resulted in the formation of surface localized ionic clusters (SLICs). These entities are capable of recognizing MMA/nBA monomer interfaces along the p-MMA/nBA copolymer backbone and form crystalline SLICs at the monomer interface. By utilizing attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy and selected area electron diffraction (SAD) combined with ab initio calculations, studies were conducted that identified the origin of SLICs as well as their structural features formed on the surface of p-MMA/nBA copolymer films stabilized by 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) PL. Specific entities responsible for SLIC formation are selective noncovalent bonds of anionic phosphate and cationic quaternary ammonium segments of DLPC that interact with two neighboring carbonyl groups of nBA and MMA monomers of the p-MMA/nBA polymer backbone. To the best of our knowledge this is the first example of molecular recognition facilitated by coalescence of copolymer colloidal particles and the ability of PLs to form SLICs at the boundaries of the neighboring MMA and nBA monomer units of the p-MMA/nBA chain. The dominating noncovalent bonds responsible for the molecular recognition is a combination of H-bonding and electrostatic interactions.

N-methyl-d-aspartate (NMDA) receptor antibodies encephalitis mimicking an autistic regression.

PubMed

Hacohen, Yael; Wright, Sukhvir; Gadian, Jonathan; Vincent, Angela; Lim, Ming; Wassmer, Evangeline; Lin, Jean-Pierre

2016-10-01

Expressive dysphasia and mutism are common clinical features in children and adults with N-methyl-d-aspartate receptor antibodies (NMDAR-Ab) encephalitis, and are likely to result from NMDAR hypofunction. A prodromal loss of social and communication skills can typify that of an autistic regression, particularly when presenting under the age of 3 years. Here we describe two toddlers who presented with developmental regression, particularly of their social communication skills, mimicking an autistic regression, who were found to have NMDAR-Ab in the serum and cerebrospinal fluid. Although both patients had some other neurological features, they were subtle, which resulted in delayed diagnosis of NMDAR-Ab encephalitis. Importantly, immunotherapy was beneficial in both patients, with significant improvement of their language skills and behaviour. © 2016 Mac Keith Press.

Physicochemical properties of an insensitive munitions compound, N-methyl-4-nitroaniline (MNA).

PubMed

Boddu, Veera M; Abburi, Krishnaiah; Maloney, Stephen W; Damavarapu, Reddy

2008-06-30

Accurate information on physicochemical properties of an organic contaminant is essential for predicting its environmental impact and fate. These properties also provide invaluable information for the overall understanding of environmental distribution, biotransformation, and potential treatment processes. In this study the aqueous solubility (Sw), octanol-water partition coefficient (Kow), and Henry's law constant (K(H)) were determined for an insensitive munitions (IM) compound, N-methyl-4-nitroaniline (MNA), at 298.15, 308.15, and 318.15 K. Effect of ionic strength on solubility, using electrolytes such as NaCl and CaCl2, was also studied. The data on the physicochemical parameters were correlated using the standard Van't Hoff equation. All three properties exhibited a linear relationship with reciprocal temperature. The enthalpy and entropy of phase transfer were derived from the experimental data.

Radio-methyl vorozole and methods for making and using the same

DOEpatents

Kim, Sung Won; Biegon, Anat; Fowler, Joanna S.

2014-08-12

Radiotracer vorozole compounds for in vivo and in vitro assaying, studying and imaging cytochrome P450 aromatase enzymes in humans, animals, and tissues and methods for making and using the same are provided. [N-radio-methyl] vorozole substantially separated from an N-3 radio-methyl isomer of vorozole is provided. Separation is accomplished through use of chromatography resins providing multiple mechanisms of selectivity.

Radio-methyl vorozole and methods for making and using the same

DOEpatents

Kim, Sung Won; Biegon, Anat; Fowler, Joanna S.

2014-08-05

Radiotracer vorozole compounds for in vivo and in vitro assaying, studying and imaging cytochrome P450 aromatase enzymes in humans, animals, and tissues and methods for making and using the same are provided. [N-radio-methyl] vorozole substantially separated from an N-3 radio-methyl isomer of vorozole is provided. Separation is accomplished through use of chromatography resins providing multiple mechanisms of selectivity.

SYNERGISTIC EFFECT OF HALIDE IONS ON THE CORROSION INHIBITION OF MILD STEEL IN SULPHURIC ACID USING METHYL, N-METHYL ETHYL AND ETHYL SUBSTITUTED γ-2,c-6-DIPHENYL PIPERIDIN-4-ONE SEMICARBAZONES

NASA Astrophysics Data System (ADS)

Priya, V. Shanmuga; Rani, C. Uma; Velrani, S.

The synergistic effect of halide ions such as KCl, KBr and KI on the corrosion inhibition of mild steel in 1 N sulphuric acid by γ-2,c-6-diphenyl-t-3-methyl piperdin-4-ones with semicarbazone (01SC), γ-2,c-6-diphenyl-N-methyl-t-3-ethyl piperdin-4-ones with semicarbazone (02SC) and 2,6-diphenyl-t-3-ethyl piperdin-4-one with semicarbazone (03SC) has been examined by weight loss method, potentiodynamic polarization measurements and electrochemical AC impedance spectroscopy. Results show that substituted γ-2,c-6-diphenyl piperidin-4-ones with semicarbazone act as the perfect corrosion inhibitors and their inhibition efficiency increases with the addition of halide ions. The inhibitor (01SC) shows the inhibition efficiency of 78.28% (0.2mM) by using a weight loss method. The influence of I-, Br- and Cl- anions raises the inhibition efficiency of the substituted 2,6-diphenyl piperidin-4-ones with semicarbazone due to the synergistic effect. The synergistic effect of halide ions was formed in the following order: KI > KBr > KCl.

40 CFR 302.4 - Designation of hazardous substances.

Code of Federal Regulations, 2013 CFR

2013-07-01

... aldehyde 7421-93-4 2 1 (0.454) ENDRIN AND METABOLITES N.A. 2 ** Endrin, & metabolites 72-20-8 1,2,4 P051 1... diisocyanate 101-68-8 3 5000 (2270) Methyl ethyl ketone 78-93-3 3,4 U159 5000 (2270) Methyl ethyl ketone... U138 100 (45.4) Methyl isobutyl ketone 108-10-1 3,4 U161 5000 (2270) Methyl isocyanate 624-83-9 3,4...

40 CFR 302.4 - Designation of hazardous substances.

Code of Federal Regulations, 2012 CFR

2012-07-01

... aldehyde 7421-93-4 2 1 (0.454) ENDRIN AND METABOLITES N.A. 2 ** Endrin, & metabolites 72-20-8 1,2,4 P051 1... diisocyanate 101-68-8 3 5000 (2270) Methyl ethyl ketone 78-93-3 3,4 U159 5000 (2270) Methyl ethyl ketone... U138 100 (45.4) Methyl isobutyl ketone 108-10-1 3,4 U161 5000 (2270) Methyl isocyanate 624-83-9 3,4...

40 CFR 302.4 - Designation of hazardous substances.

Code of Federal Regulations, 2014 CFR