Studies on Moss Spores. IV. Mass Spectrometric Identification of Saturated and Monoenoic Long Chain Fatty Acids in the Triglyceride Fraction of Polytrichum commune Spores

The saturated long chain fatty acid methyl esters of the triglyceride fraction of Polytrichum commune spores were separated by silver nitrate TLC and identified by a combination of gas chromatographic-mass spectrometric technique. The saturated fatty acid methyl esters were straight-chained, and even-numbered with carbon numbers ranging from 12 to 26 or odd-numbered with carbon numbers ranging from 13 to 25. The major components of the fraction containing saturated fatty acid methyl esters were methyl palmitate and methyl stearate. The fatty acid methyl esters of the monoenoic fraction isolated by silver nitrate TLC were converted to TMSO derivates which were analysed by gas chromatography-mass spectrometry. The analysis gave evidence of positional isomers. The fraction contained the following straight chain monoenoic fatty acid methyl ester isomers: methyl 7-cis-hexadecenoate, methyl 9-cis-hexadecenoate, methyl 9-cis-heptadecenoate, methyl 9-cis-octadecenoate, methyl 11-cis-octadecenoate, and methyl 11-cis-eicosenoate. The major components were methyl 9-cis-octadecenoate and methyl 7-cis-hexadecenoate.     

Pentacyclic triterpenes from Myrianthus liberecus

From the methylated trunk wood extracts of Myrianthus liberecus, six pentacyclic triterpenes have been isolated as their methyl esters. These included the known methyl benthamate, methyl euscaphate, methyl tormentate, methyl arjunolate, methyl 3-isoarjunolate and methyl 3β-O-(4″-O-methyl-E-coumaroyl)-arjunolate, a new triterpene derivative.     

Cervical dilatation with prostaglandin analogues prior to vaginal termination of first trimester pregnancy in nulliparous patients.

Dilatation of the cervix with prostaglandin analogues prior to vaginal termination of pregnancy was attempted in 125 nulliparous women in the first trimester of pregnancy. The patients were divided into five groups (25 in each group) and given a single extra-amniotic dose of one of the following prostaglandin analogues 14-16 hours prior to the evacuation of the uterus by vacuum aspiration. (Group A) 15 (S) 15 methyl PGE2 (free acid); (Group B) 15 (S) 15 methyl PGE2 methyl ester; (Group C) 15 (S) 15 methyl PGF2alpha (free acid); (Group D) 15 (S) 15 methyl PGF2alpha methyl ester and(Group E) a mixture of 15 (S) 15 methyl PGE2methyl ester and 15 (S) 15 methyl PGF2alpha methyl ester. Evacuation of the uterus without mechanical dilatation of the cervix was possible in 111 (90%) of the patients. In an additional 10 patients (8%) there was some degree of cervical dilatation and further mechanical dilatation could be performed easily. With the combination of 15 (S) 15 methyl PGE2 methyl ester and 15 (S) 15 methyl PGF2alpha methyl ester the incidence of gastrointestinal side effects and pyrexia were considerably reduced.     

Evidence for the presence of a CmuA methyltransferase pathway in novel marine methyl halide-oxidizing bacteria

Marine bacteria that oxidized methyl bromide and methyl chloride were enriched and isolated from seawater samples. Six methyl halide-oxidizing enrichments were established from which 13 isolates that grew on methyl bromide and methyl chloride as sole sources of carbon and energy were isolated and maintained. All isolates belonged to three different clades in the Roseobacter group of the alpha subdivision of the Proteobacteria and were distinct from Leisingera methylohalidivorans, the only other identified marine bacterium that grows on methyl bromide as sole source of carbon and energy. Genes encoding the methyltransferase/corrinoid-binding protein CmuA, which is responsible for the initial step of methyl chloride oxidation in terrestrial methyl halide-oxidizing bacteria, were detected in enrichments and some of the novel marine strains. Gene clusters containing cmuA and other genes implicated in the metabolism of methyl halides were cloned from two of the isolates. Expression of CmuA during growth on methyl halides was demonstrated by analysis of polypeptides expressed during growth on methyl halides by SDS-PAGE and mass spectrometry in two isolates representing two of the three clades. These findings indicate that certain marine methyl halide degrading bacteria from the Roseobacter group contain a methyltransferase pathway for oxidation of methyl bromide that may be similar to that responsible for methyl chloride oxidation in Methylobacterium chloromethanicum. This pathway therefore potentially contributes to cycling of methyl halides in both terrestrial and marine environments.     

Studies on Abscisic Acid

Methyl α-cyclocitrylideneacetate was successively oxidized with selenium dioxide and chromium trioxide-pyridine complex to give methyl 1′-hydroxy-α-cyclocitrylideneacetate and a mixture of methyl 3′-keto-β-cyclocitrylideneacetate and methyl 4′-keto-α-cyclocitrylideneacetate. Further, oxidation of methyl α-cyclocitrylideneacetate with tert-butyl chromate afforded methyl 4′-keto-α-cyclocitrylideneacetate and methyl 1′-hydroxy-4′-keto-α-cyclocitry-lineacetate. Similarly, methyl α-cyclogeranate was oxidized to methyl 3-keto-β-cyclogeranate and methyl 4-keto-α-cyclogeranate. Methyl l′-hydroxy-4′-keto-α-cyclocitrylideneacetate, methyl l-hydroxy-4-keto-α-cyclogeranate and their related compounds did not show growth inhibitory activities on rice seedlings.     

Fatty acid composition of seeds of Satureja thymbra and S. cuneifolia

The chemical composition of fatty acid methyl esters (FAMEs) from seeds of S. thymbra and S. cuneifolia were analyzed by GC/MS. 7 FAMEs were identified from the seeds of S. thymbra mainly as 9-octadecenoic acid methyl ester (43.9%), hexadecanoic acid methyl ester (11.4%), 9,12,15-octadecatrienoic acid methyl ester (Z,Z,Z) (30.2%), and octadecanoic acid methyl ester (14.1%), while from the seed of S. cuneifolia 10 FAMEs were obtained with the main components, similar to S. thymbra. These were identified as 9-octadecenoic acid methyl ester (10.1%), hexadecanoic acid methyl ester (methyl palmitate, 34.6%), 9,12,15-octadecatrienoic acid methyl ester (Z,Z,Z) (6.3%) and octadecanoic acid methyl ester (1.8%).     

Feeding stimulants eliciting the probing behavior for Peregrinator blannulipes Montrouzier et Signore (Hemiptera: Ruduviidae) from Tribolium confusum (Jacquelin du Val)

Four fatty acid methyl esters identified in the solvent extract of Tribolium confusum (Jacquelin du Val) larvae as kairomones were individually and collectively tested for probing behavior of Peregrinator biannulipes Montrouzier et Signoret. All identified fatty acid methyl eaters, methyl palmitate, methyl linolate, methyl oleate and methyl stearate, exhibited characterisitic kairomonal probing behavior of P. biannulipe toward the lure. These fatty acid methyl ester were active at 0.2 microg/lure but a synergistic effect was not observed among them. Commercially available C8-C14 even-numbered fatty acid methyl esters that were not detected in the extract of T. confusum larvae also elicited a probing behavior but their activities were weaker than those of four fatty acid methyl ester (C16:0, C18:0, C18:1 and C18:2) identified in the extract. On the other hand, C17 and C19 odd-numbered fatty acid methyl esters did not show any activity at all.     

Synthesis of methyl pyranosides and furanosides of 3-deoxy-D-manno-oct-2-ulosonic acid (KDO) by acid-catalysed solvolysis of the acetylated derivatives

Treatment of methyl 2,4,5,7,8-penta-O-acetyl-3-deoxy-alpha-D-manno-oct- 2-ulopyranosonic acid, or its methyl ester, with refluxing methanolic 0.1 M hydrogen chloride for 16 h gave 95% of methyl (methyl 3-deoxy-alpha-D-manno-oct-2-ulopyranosid)onate. Acetylation of the methyl ester of 3-deoxy-D-manno-oct-2-ulosonic acid (KDO) gave mainly methyl 2,4,6,7,8-penta-O-acetyl-3-deoxy-alpha,beta-D-manno-oct-2-ulofuranoso nate. Treatment of this mixture with methanolic 0.02 M hydrogen chloride at room temperature gave methyl (methyl 3-deoxy-alpha, beta-D-manno-oct-2-ulofuranosid)onate and the corresponding 4-acetates which were isolated by reverse-phase column chromatography of their 7,8-O-isopropylidene derivatives. Confirmation of the position of the isopropylidene group was obtained by acetylation to give methyl (methyl 4,6-di-O-acetyl-3-deoxy-7,8-O-isopropylidene-alpha,beta-D-manno-oct-2-ul ofuranosid)onate. The furanose anomers were differentiated primarily by J3,4 values (alpha approximately 6.1 Hz, beta approximately 2.2 Hz). The anomeric configuration in the furanose series has been assigned on the basis of optical rotation.     

Synthesis of disaccharide fragments of dermatan sulfate

Condensation of crystalline methyl 2-azido-4,6-O-benzylidene-2-deoxy-beta-D-galactopyranoside with methyl (2,3,4-tri-O-acetyl-alpha-L-idopyranosyl bromide)uronate in dichloromethane, in the presence of silver triflate and molecular sieve, provided 54% of methyl 2-azido-4,6-O-benzylidene-2-deoxy-3-O-(methyl 2,3,4-tri-O-acetyl-alpha-L-idopyranosyluronate)-beta-D-galactopyranoside . The use of methyl (2,3,4-tri-O-acetyl-alpha-L-idopyranosyl trichloroacetimidate)uronate as glycosyl donor, in the presence of trimethylsilyl triflate, improved the yield to 68%. Regioselective opening of the benzylidene group with sodium cyanoborohydride followed successively by O-sulfation with the sulfur trioxide-trimethylamine complex, saponification, catalytic hydrogenolysis and selective N-acetylation gave the disodium salt of methyl 2-acetamido-2-deoxy-3-O-(alpha-L-idopyranosyluronic acid)-4-O-sulfo-beta-D-galactopyranoside. Condensation of methyl 2-azido-4,6-O-benzylidene-2-deoxy-beta-D-galactopyranoside with methyl (2,3,4-tri-O-acetyl-alpha-D-glucopyranosyl bromide)uronate in dichloromethane, in the presence of silver triflate and molecular sieve, gave methyl 2-azido-4,6-O-benzylidene-2-deoxy-3-O-(methyl 2,3,4-tri-O-acetyl-beta-D-glucopyranosyluronate)-beta-D-galactopryano side in 85% yield. The sequence already described then gave the disodium salt of methyl 2-acetamido-2-deoxy-3-O-(beta-D-glucopyranosyluronic acid)-4-O-sulfo-beta-D-galactopyranoside.     

A (13)C NMR study on the interactions of calcium chloride/potassium chloride with pyranosides in D(2)O

The (13)C NMR spectra of methyl beta-d-glucopyranoside, methyl beta-d-galactopyranoside, methyl beta-d-xylopyranoside, and methyl beta-l-arabinopyranoside were recorded in CaCl(2)/KCl+D(2)O mixtures and in D(2)O. The chemical shifts of C-1, C-3, and C-5 in the methyl beta-d-glucopyranoside and methyl beta-d-galactopyranoside decrease rapidly as molalities of CaCl(2)/KCl increase, while those of C-1, C-2, and C-3 in the methyl beta-d-xylopyranoside and methyl beta-l-arabinopyranoside decrease rapidly as molalities of CaCl(2)/KCl increase. Cations (Ca(2+)/K(+)) can weakly complex with O in OMe of the pyranosides studied. Results are discussed in terms of the stereochemistry of the pyranoside molecules and the structural properties of the ions.     

Model sclerotization studies. 3. Cuticular enzyme catalyzed oxidation of peptidyl model tyrosine and dopa derivatives

Incubation of N-acetyltyrosine methyl ester with cuticular enzymes, isolated from the wandering stages of Calliphora sp larvae, resulted in the generation of N-acetyldopa methyl ester when the reaction was carried out in the presence of ascorbate which prevented further oxidation of the o-diphenolic product. Enzymatic oxidation of N-acetyldopa methyl ester ultimately generated dehydro N-acetyldopa methyl ester. The identity of enzymatically produced N-acetyldopa methyl ester and dehydro N-acetyldopa methyl ester has been confirmed by comparison of the ultraviolet and infrared spectral and chromatographic properties with those of authentic samples as well as by nuclear magnetic resonance studies. Since N-acetyldopaquinone methyl ester was also converted to dehydro N-acetyldopa methyl ester and tyrosinase was responsible for the oxidation of N-acetyldopa methyl ester, a scheme for the cuticular phenoloxidase catalyzed conversion of N-acetyltyrosine methyl ester to dehydro N-acetyldopa methyl ester involving the intermediary formation of the quinone and the quinone methide is proposed to account for the observed results. The conversion of N-acetyldopa methyl ester to dehydro derivative remarkably resembles the conversion of the sclerotizing precursor, N-acetyldopamine, to dehydro-N-acetyl-dopamine observed in the insect cuticle. Based on these comparative studies, it is proposed that peptidyl dopa derivatives could also serve as the sclerotizing precursors for the sclerotization of the insect cuticle. © 1995 Wiley-Liss, Inc.     

Alternansucrase acceptor reactions with methyl hexopyranosides

Alternansucrase (EC 2.4.1.140, sucrose: (1-->6), (1-->3)-alpha-D-glucan 6(3)-alpha-D-glucosyltransferase) is a D-glucansucrase that synthesizes an alternating alpha-(1-->3), (1-->6)-linked D-glucan from sucrose. It also synthesizes oligosaccharides via D-glucopyranosyl transfer to various acceptor sugars. We have studied the acceptor products arising from methyl glycosides as model compounds in order to better understand the specificity of alternansucrase acceptor reactions. The initial product arising from methyl beta-D-glucopyranoside was methyl beta-isomaltoside, which was subsequently glucosylated to yield methyl beta-isomaltotrioside and methyl alpha-D-glucopyranosyl-(1-->3)-alpha-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside. These products are analogous to those previously described from methyl alpha-D-glucopyranoside. The major initial acceptor product from methyl alpha-D-mannopyranoside was methyl alpha-D-glucopyranosyl-(1-->6)-alpha-D-mannopyranoside, but several minor products were also isolated and characterized, including a 3,6-di-O-substituted mannopyranoside. Methyl alpha-D-galactopyranoside yielded two initial products, methyl alpha-D-glucopyranosyl-(1-->3)-alpha-D-galactopyranoside and methyl alpha-D-glucopyranosyl-(1-->4)-alpha-D-galactopyranoside, in a 2.5:1 molar ratio. Methyl D-allopyranosides were glucosylated primarily at position 6, yielding methyl alpha-D-glucopyranosyl-(1-->6)-D-allopyranosides. The latter subsequently gave rise to methyl alpha-D-glucopyranosyl-(1-->6)-alpha-D-glucopyranosyl-(1-->6)-D-allopyranosides. In general, the methyl alpha-D-hexopyranosides were better acceptors than the corresponding beta-glycosides.     

Methyl chanofruticosinates from leaves of Kopsia flavida Blume

Three new indole alkaloids with methyl chanofruticosinates skeletal system, viz., methyl 12-methoxy-N1-decarbomethoxychanofruticosinate, methyl 12-methoxychanofruticosinate and methyl 11,12-dimethoxychanofruticosinate, in addition to methyl 11,12-methylenedioxy-N1-decarbomethoxychanofruticosinate, have been isolated from the leaves of Kopsia flavida Blume. The structures of these three new indole alkaloids were assigned by NMR spectral data using various 2D-techniques.     

左旋多巴甲酯在PLGA微球的稳定性研究

目的：考察左旋多巴甲酯在PLGA微球中的稳定性并探讨其稳定方法。方法：利用HPLC的方法考察了左旋多巴甲酯在不同pH值和光照的环境中和微球里的稳定性。结果：左旋多巴甲酯在pH3中稳定,在微球中也可以稳定一周。结论：包封左旋多巴甲酯在PLGA微球中,是一种有效地保护了左旋多巴甲酯在微球中的活性,可以实现长效缓释,是一种可行的方案。     

Cervical dilatation with prostaglandin analogues prior to vaginal termination of first trimester pregnancy in nulliparous patients

Dilatation of the cervix with prostaglandin analogues prior to vaginal termination of pregnancy was attempted in 125 nulliparous women in the first trimester of pregnancy. The patients were divided into five groups (25 in each group) and given a single extra-amniotic dose of one of the following prostaglandin analogues 14–16 hours prior to the evacuation of the uterus by vacuum aspiration. (Group A) 15 (S) 15 methyl PGE₂ (free acid); (Group B) 15 (S) 15 methyl PGE₂ methyl ester; (Group C) 15 (S) 15 methyl PGF_2α (free acid); (Group D) 15 (S) 15 methyl PGF_2α methyl ester and(Group E) a mixture of 15 (S) 15 methyl PGE₂ methyl ester and 15 (S) 15 methyl PGF_2α methyl ester. Evacuation of the uterus without mechanical dilatation of the cervix was possible in 111 (90%) of the patients. In an additional 10 patients (8%) there was some degree of cervical dilatation and further mechanical dilatation could be performed easily. With the combination of 15 (S) 15 methyl PGE₂ methyl ester and 15 (S) 15 methyl PGF_2α methyl ester the incidence of gastrointestinal side effects and pyrexia were considerably reduced.     

Nuclear magnetic resonance studies of hemoproteins. IV. Hindered rotation of heme side methyl group as a probe for studying van der Waals contacts in the heme side environments of myoglobin derivatives.

220 MHz roton NMR spectral evidence for restricted rotation of one methyl group in the heme side chain of ferric horse cyanomyoglobin is reported here. Temperature dependence of this methyl proton signal was computer-simulated, yielding 14,8 kcal/mol for the methyl hindered rotation. Ionic additives such as NaCl and (NH4) 2 minus SO4 caused a slackening of this restriction of methyl rotation, evidenced from collapse of methyl signal doubling by the addition of these ionic substances. This is discussed in terms of breaking of the salt bridge formed between one of the propionate COO minus group of heme and a part of the apoprotein which might lead to constraint of one of the heme side methyl groups. The peculiarity of hyperfine-shifted methyl proton signals for other myoglobin complexes such as azide and imidazole derivatives is also discussed briefly in terms of constraint of heme side methyl group buried in a hydrophobic cleft.     

麦长管蚜和禾谷缢管蚜对小麦挥发物的触角电位反应

采用活体蚜虫测定法,利用EAG技术比较分析了麦长管蚜Sitobion avenae和禾谷缢管蚜Rhopalosiphum padi有翅及无翅成蚜对小麦挥发物及麦蚜取食诱导挥发物组分的嗅觉反应,揭示了两种麦蚜的嗅觉变异特点。结果表明：麦长管蚜对水杨酸甲酯、反-2-己烯醛、反-2-己烯醇、-6-甲基-5-庚烯-2-酮和-6-甲基-5-庚烯-2醇的反应较强,禾谷缢管蚜对水杨酸甲酯、反-3-己烯乙酸酯、-6-甲基-5-庚烯-2-酮和-6-甲基-5-庚烯-2-醇的反应较强,并得到了剂量反应曲线。麦长管蚜的有翅和无翅成蚜对6-甲基-5-庚烯-2-酮、反-2-己烯醇和水杨酸甲酯的反应差异显著;禾谷缢管蚜的有翅和无翅成蚜对反-2-己烯醇、辛醛、里那醇、水杨酸甲酯和反-3-己烯乙酸酯的EAG反应差异显著,其原因与禾谷缢管蚜迁移及转主为害的生物学特性有关。     

Ectomycorrhizal fungi: A new source of atmospheric methyl halides?

Incomplete source budgets for methyl halides – compounds that release inorganic chlorine and bromine radicals which, in turn, catalyze atmospheric ozone depletion – limit our ability to predict the fate of the stratospheric ozone layer. We report here the first measured emissions of methyl chloride, methyl bromide, and methyl iodide from ectomycorrhizal fungi. We grew nine fungal isolates on growth media containing halide concentrations similar to those found in soils and plant tissues. The observed range of emissions was 0.003–65 μg methyl chloride, 0.001–3 μg methyl bromide, and 0.02–12 μg methyl iodide g^?1 dry weight fungi day^?1. Species varied in production rates of methyl chloride vs. methyl bromide vs. methyl iodide. Cenococcum geophilum, a widespread ectomycorrhizal fungus, was further tested to investigate the effects of halide substrate concentration in growth media. Emissions from this species increased linearly with increasing concentrations of both bromide and iodide. In addition, a subset of four fungi was studied with two media concentrations each of chloride, bromide, and iodide (0.2 or 20 mm ). These fungi had similar responses to halide concentration, despite 1000‐fold differences in baseline emission rates between isolates. Finally, high chloride concentrations (20 mm ) in media did not appear to inhibit emissions of methyl bromide or methyl iodide. Overall, ectomycorrhizal fungi might be an important source of methyl halides to the atmosphere, and substrate concentrations and community composition may influence production levels in ecosystems.     

Fatty acids,part 12. The synthesis of furanoid, α,β-unsaturated oxocyclopentenyl and oxocyclohexenyl esters from methyl octadecadiynoates

Hydration of methyl 7,11-octadecadiynoate gives the 1,4-dioxo(methyl 8,11-dioxostearate) and 1,5-dioxo(methyl 7,11- and 8,12-dioxostearate) derivatives, while methyl 8,13-octadecadiynoate furnishes only the corresponding 1,5- and 1,6-dioxo derivatives when the diacetylenic esters are treated with mercuric acetate aqueous tetrahydrofuran. Acid catalysed condensation reactions of 1,4-, 1,5- and 1,6-dioxo derivatives of methyl stearate give furanoid, α,β-unsaturated oxocyclohexenyl and pentenyl derivatives respectively, while reaction of the dioxo esters with alcoholic KOH provides α,β-unsaturated oxocyclohexenyl and pentenyl derivatives of methyl stearate.