团花树皮的化学成分研究

采用硅胶、MCI和Sephadex LH-20层析方法对团花树皮的化学成分进行分离纯化,运用现代波谱技术鉴定了10个化合物:4-carboxy-3-hydroxy-5-methylphenyl 3-methoxy-4-hydroxy-5-methylbenzoate(1),谷甾醇-3-O-(6’-O-棕榈酰基)-β-D-葡萄糖苷(2),喹诺酸-3-O-α-L-鼠李糖苷(3),clethric acid(4),常春藤苷元(5),钩藤苷元C(6),morolic acid(7),咖啡酸甲酯(8),卡丹宾(9)和3α-二氢卡丹宾(10)。其中化合物1为一个新的酚性成分,化合物2～8首次从该属植物中分离得到。     

异叶三宝木叶的化学成分研究(英文)

从异叶三宝木(Trigonostemon flavidus)叶中分离得到9个化合物,经波谱数据分析鉴定为robustic acid(1),1-[6-hydroxy-2-methoxy-2″,2″-dimethylpyrano-(5″,6″:3,4)]-2-(4’-methoxyphenyl)-1,2-ethanedione(2),3β-ursolic acid(3),(6S,7E)-6-hydroxy-4,7-megastigmadien-3,9-dione(4),3(-hydroxy-5,6-epoxy-7-megastigmen-9-one(5),(3R,6R,7E)-3-hydroxy-4,7-megastigmadien-9-one(6),loliolide(7),methyl P-coumarate(8),和methyl si-napate(9)。化合物1～7和9为首次从三宝木属(Trigonostemon)植物中分离得到。     

肾茶化学成分研究

采用色谱法从肾茶中分离得到18个化合物,利用波谱学方法鉴定了它们的结构,分别命名为(7'S,8'S)-8-epiblechnic acid diacetate(1)、threo-2-(4-hydroxy-3,5-dimethoxyphenyl)-3-(4-hydroxy-3-methoxyphenyl)-3-ethoxypropan-1-ol(2)、9-hydroxy-4,7-megastigmadien-3-one(3),dehydrololiolide(4),3-hydroxy-4-oxo-7,8-dihydro-β-ionone(5)、3-hydroxy-7,8-dehydro-β-ionol(6)、3-hydroxy-5,6-epoxy-β-ionone(7)、loliolide(8)、threo-2,3-bis(4-hydroxy-3-methoxyphenyl)-3-ethoxy-propan-1-ol(9)、erythro-2,3-bis-(4-hydroxy-3-methoxyphenyl)-3-ethoxypropan-1-ol(10)、松脂醇(11)、(+)-丁香脂素(12)、(+)-(7R,7'R,7'R,7''R,8S,8'S,8'S,8''S)-4',4''-dihydroxy-3,3',3',3'',5,5'-hexame-thoxy-7,9':7',9-diepoxy-4,8':4',8''-bisoxy-8,8'-dineolignan-7',7'',9',9''-tetraol(13)、fragransin B1(14)、fragransin B2(15)、fragransin B3(16)、sacidumol A(17)和5,6,7,3',4'-五甲氧基黄烷酮(18)。其中化合物1和2为新化合物,除了化合物12和18外,其余化合物均为首次从肾茶属中被分离得到。化合物1由于含有二个乙氧基,因此其可能产生于分离过程,我们采用ECD计算确定了其绝对构型。     

锥序蜜心果中酚性成分的研究

从锥序蜜心果的乙酸乙酯部分中分离到5个化合物,通过波谱数据或与已知化合物对照,它们分别鉴定为(E)-3-(3-hydroxy-4-methoxyphenyl)acrylic acid carboxymethyl ester(1),3,4-二羟基苯甲酸(2),槲皮素-3-O-β-葡萄糖甙(3),山萘酚-3-O-α-鼠李糖甙(4)和槲皮素-3-O-α-鼠李糖甙(5),以上化合物均为首次从该属植物中分离到.     

广东土牛膝的化学成分(英文)

广东土牛膝为菊科泽兰属植物华泽兰(Eupatorium chinense)的干燥根。从其甲醇提取物中共分离得到11个化合物,其中eupatorinA(1)为一新化合物,经波谱学方法鉴定为(threo)-3-O-acetyl-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxy-1-(E)-propenyl)-2,6-dimethoxyphenoxy]propyl-β-D-glucopy-ranoside。已知化合物分别鉴定为(threo)-3-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxy-1-(E)-propenyl)-2,6-dimethoxyphenox-y]-propyl-β-D-glucopyranoside(2),ardisiacrispinA(3),ardisiac-rispinB(4),euparone(5),3-(2,3-dihydroxy-isopen-tyl)-4-hydroxyacetophenone(6),12,13-di-hydroxy-euparin(7),gymnastone(8),N-(2′-hydroxy-tetracosanosyl)-2-amino-1,3,4-trihydroxy-octa-dec-8-(E)-ene(9),stigmasterol(10)和stigmasterol-3-O-β-D-glucopyranoside(11)。化合物2-4为首次从菊科植物,5-8为首次从泽兰属植物中分离得到。     

岗松化学成分的研究

从岗松的石油醚和氯仿提取组分中分离得到7个化合物,根据NMR、HSQC、HMBC、IR和MS的数据分析及与文献对照,确定它们的结构为白桦脂酸(betulinic acid,1),齐墩果酸(oleanolic acid,2),没食子酸乙酯(ethyl sabre,3),5-羟基-6-甲基-7-甲氧基-二氢黄酮(5-hydroxy-6-methyl-7-methoxy-flavanone,4),5-羟基-7-甲氧基-8-甲基二氢黄酮(5-hydroxy-7-methoxy-8-methylflavanone,5),5-羟基-7-甲氧基-2-异丙基色原酮(5-hydroxy-7-methoxy-2-isopropylchromone,6)和β-谷甾醇(β-sitosterol,7).其中,化合物1～5和7为首次从该植物中分离得到.     

龙眼独活中的一个新二萜成分

从四川产木属(Aralia)草本植物龙眼独活(Aralia fargesii Franch.)根茎的石油醚提取部分分离得到4个二萜化合物,根据理化性质测定和各种光谱(IR、EI-MS、HREI-MS、1H-NMR、13C-NMR和HMQC)数据分析,它们的结构分别鉴定为17-acetoxy-16α-ent-kauran-19-oic acid (1), ent-pimara-8(14),15-dien-19-oic acid (2), 16α-hydroxy-(-)-kauran-19-oic acid (3) 和16α-17-dihydroxy-ent-kauran-19-oic acid (4).化合物1为新化合物,3为首次从该属植物中分离得到,2～4为首次从龙眼独活中分离得到.     

嗜低温真菌Pseudogymnoascus pannorum次级代谢产物研究

本文采用现代色谱分离手段从嗜低温真菌Pseudogymnoascus pannorum的大米发酵产物中分离得到8个化合物,采用现代波谱技术鉴定其结构,分别为:L-pyroglutamyl-L-phenylalanine(1)、(R)-N-acetylphenylalanine(2)、(R)-Nacetyltryptophan (3)、methyl 2-hydroxy-4-(3-hydroxy-5-methylphenoxy)-6-methylbenzoate (4)、2-hydroxy-4-(2-hydroxy-3-methoxy-5-methylphenoxyl)-6-methylbenzoate(5)、vanillic acid(6)、1,3,5-三甲氧基苯(7)和亚油酸(8)。其中化合物1和2为首次从天然界分离得到,化合物3～8为首次从假裸囊菌属真菌中分离得到。化合物1～8对人肝癌细胞Hep G-2和人乳腺癌细胞MCF-7未显示细胞毒作用。     

柳叶白前化学成分研究

从柳叶白前根和茎中分离并鉴定了7个化合物,分别为β-谷甾醇（β-sitosterol,1）,2,4-二羟基苯乙酮（1-（2,4-dihydroxphenyl）ethanone,2）,间二苯酚（resorcinol,3）,4-羟基-3-甲氧基苯乙酮（1-（4-hydroxy-3-methoxyphenyl）e-hanone,4）,4-羟基苯乙酮（1-（4-hydroxyphenyl）ethanone,5）,齐墩果酸（oleanolic acid,6）,蔗糖（sucrose,7）。其中化合物2-7为首次从该植物中分得。     

高良姜中的抗氧化有效成分

从高良姜(Alpinia officinarum Hance)中分离了7个化合物,其中4个二苯基庚烷类化合物:1,7-diphenylhept-4-en-3-one(Ⅰ),7-(4”-hydroxy-3”-methoxyphenyl)-1-phenyl-hept-4-en-3-one(Ⅱ),5-hydroxy-7-(4”-hydroxy-3”-methoxyphenyl)-1-pheny-3-heptanone(Ⅲ),5-methoxy-7-(4”-hydroxy-3”-methoxyphenyl)-1-phenyl-3-heptanone(Ⅳ);3个黄酮醇类化合物;鼠李柠檬素(rhamnocitrin)(Ⅴ),山奈素-4’-甲醚(kaempferol-4’-methylether)(Ⅵ)及高良姜素(galangin)(Ⅶ)。用维生素C诱发肝微粒体脂质过氧化方法测定了以上化合物的抗脂质过氧化活性。黄酮醇类化合物具有较强的抗氧化活性,二苯基庚烷类化合物除化合物Ⅰ外都显示了中等强度的抗氧化活性。     

Biosynthesis of novel copolyesters containing 3-hydroxypivalic acid by Rhodococcus ruber NCIMB 40126 and related bacteria

Rhodococcus ruber and related Gram-positive bacteria synthesized and accumulated novel copolyesters containing 3-hydroxypivalic acid as constituent if the cells were cultivated in a mineral salts medium containing 3-hydroxypivalic acid and glucose as carbon sources. The copolyesters contributed 0.4–10% of the cellular dry mass, and they contained up to 78 mol% of 3-hydroxypivalic acid in addition to 3-hydroxybutyric acid and 3-hydroxyvaleric acid; a homopolyester of 3-hydroxypivalic acid was also synthesized under certain conditions. The presence of 3-hydroxypivalic acid in the accumulated copolyesters was confirmed by nuclear magnetic resonance spectrometry as well by coupled gas chromatography/mass spectrometry. This is the first time that the incorporation of 3-hydroxypivalic acid and therefore of a hydroxyalkanoic acid with two methyl group substituents at the α-carbon atom in a naturally occurring copolyester is reported. It indicates that 3-hydroxypivalic acid-coenzyme A is accepted by polyhydroxyalkanoic acid synthase as a substrate.     

3-Hydroxyanthranilic acid-derived compounds formed through electrochemical oxidation

3-Hydroxyanthranilic acid (3-HAA)-derived oxidation products were analyzed using high-performance liquid chromatography with an electrochemical reactor and diode array detection and high-performance liquid chromatography with an electrochemical reactor and UV detection coupled with mass spectrometry. In addition to 3-HAA dimers such as cinnabarinic acid (CA), 6-amino-3-[(2-carboxy-6-hydroxyphenyl)amino]-2,5-dioxo-1,3-cyclohexadiene-1-carboxylic acid and 4,7-diamino-8-hydroxy-6H-dibenzo[a,d]pyran-6-one-3-carboxylic acid, a 3-HAA trimer and a 3-HAA tetramer were also detected and identified based on their electrospray ionization mass spectra and their UV–visible spectra. These five oxidation products were also detected on the elution profiles of high-performance liquid chromatography–diode array detection analyses for the reaction mixtures of the auto-oxidation of 3-HAA, of 3-HAA with potassium ferricyanide, of 3-HAA with horseradish peroxidase and hydrogen peroxide, and of 3-HAA with superoxide dismutase (SOD). 4,7-Diamino-8-hydroxy-6H-dibenzo[a,d]pyran-6-one-3-carboxylic acid was predominant in the auto-oxidation, in the reaction of 3-HAA with horseradish peroxidase and hydrogen peroxide, and in the electrochemical oxidation of 3-HAA at an applied potential of 0.0 V. On the other hand, CA, the 3-HAA trimer and the 3-HAA tetramer were predominant in the reaction of 3-HAA with K₃[Fe(CN)₆] and in the electrochemical oxidation of 3-HAA at an applied potential of 1.0 V.     

Quantification of 3-hydroxyglutaric acid in urine,plasma, cerebrospinal fluid and amniotic fluid by stable-isotope dilution negative chemical ionization gas chromatography-mass spectrometry

This paper describes a stable isotope dilution method for quantification of 3-hydroxyglutaric acid (3-HGA) in body fluids. The method comprises a solid-phase extraction procedure, followed by gas chromatographic separation and negative chemical ionization mass spectrometric detection. This method is selective and sensitive, and enables measurement of 3-HGA concentrations in urine-, plasma-, and CSF- samples of controls. The control ranges for 3-HGA were: urine 0.88-4.5 mmol/mol creatinine (n=12); plasma 0.018-0.10 micro mol/l (n=10), CSF 0.022-0.067 micro mol/l (n=10). We applied this method to measure 3-HGA in body fluids of three patients with glutaric aciduria type I. We also quantified 3-HGA in amniotic fluid of controls (range 0.056-0.11 micro mol/l; n=12) and in two samples from fetuses affected with glutaric aciduria type I.     

Analytical method for the determination of urinary 3-phenoxybenzoic acid in subjects occupationally exposed to pyrethroid insecticides

The determination of urinary 3-phenoxybenzoic acid enables exposure to pyrethroid insecticides to be evaluated. A method for the quantitative determination of this metabolite in urine is described. The compound and the internal standard (2-phenoxybenzoic acid) are derivatized with pentafluorobenzylbromide and transformed into pentafluorobenzyl esters, which are determined by gas chromatography with an intermediate polarity capillary column and an electron-capture detector. Before GC analysis, the urinary extracts are purified on LC-Si SPE columns. The proposed method has a detection limit of 0.5 μg/l and a mean recovery of 91.3%. The coefficient of variation of the analytical procedure, evaluated at a concentration of 24.96 μg/l, was 9.58%. Storage of the urine samples for 3 months at −18°C did not lead to significant changes in the concentration of analyte. The method was tested analysing the urine of a farm worker with symptoms of pyrethroid poisoning, occupationally exposed to esfenvalerate.     

Auxin effects on rooting in pea cuttings

Light-grown stem cuttingss of Pisum sativum L. cv. Weibull's Marma were rooted in a nutrient solution. The presence of 10 μ M indolylacetic acid (IAA) in the solution for 24 h or longer periods decreased the number of roots subsequently formed to about 50% of control, provided IAA was present in the solution during any of the 4 first 24 h periods. Treatment for 6 h or shorter periods caused no or small response. IAA did not appreciably change the time needed for root formation, the time course of root appearance or the pattern of root distribution along the basal internode. IAA at 100 μ M usually increased the number of roots although variable results were obtained with this IAA concentration.
The number of roots was strongly increased by treatment with indolylbutyric acid (IBA) or 2,4-dichlorophenoxyacetic acid (2,4-D). None of these or other synthetic auxins decreased the number of roots in suboptimal concentrations. Experiments with 10 μ M IBA showed that stimulation of rooting was obtained only if the auxin was present in the rooting solution for several days. Simultaneous treatment with IAA decreased the stimulating effect of IBA to some extent, whereas no such response was obtained if IAA was combined with 2,4-D.
IAA applied in lanolin to the stem of intact cuttings decreased the number of roots formed. Decapitation and debudding of the cuttings decreased the number of roots formed. If at least 2 leaves were left this decrease was efficiently counteracted by an optimal IAA dose applied to the upper part of the stem. A five times higher dose was less effective, indicating a negative effect on rooting also by IAA applied to the shoots.     

The influence of different combinations of gamma-linolenic, stearidonic and eicosapentaenoic acids on the fatty acid composition of blood lipids and mononuclear cells in human volunteers

This study set out to identify whether stearidonic acid (18:4n-3; STA) can be used to increase the eicosapentaenoic acid (20:5n-3; EPA) content of plasma lipids and cells in humans and to understand more about the effects of increased consumption of gamma-linolenic acid (18:3n-3; GLA), STA and EPA in humans. Healthy young males were randomised to consume one of seven oil blends for a period of 12 weeks (9g oil/day) (n = 8-12 subjects/group). Palm oil, sunflower oil, an EPA-rich oil, borage oil (rich in GLA), and Echium oil (rich in STA) were blended in various combinations to generate a placebo oil and oils providing approximately 2g GLA + STA + EPA per day, but in different combinations. Blood was collected at 0, 4, 8 and 12 weeks and the fatty acid compositions of plasma triacylglycerols, cholesteryl esters and phospholipids and of peripheral blood mononuclear cells (PBMCs) determined. Significant effects were observed with each lipid fraction. Neither STA nor its derivative 20:4n-3 appeared in any of the lipid fractions studied when STA (up to 1g/day) was consumed. However, STA (1g/day), in combination with GLA (0.9 g/day), increased the proportion of EPA in some lipid fractions, suggesting that STA-rich plant oils may offer a novel means of increasing EPA status. Furthermore, this combination tended to increase the dihomo-gamma-linolenic acid (20:3n-6; DGLA) content of PBMCs, without an increase in arachidonic acid (AA) (20:4n-6) content. EPA consumption increased the EPA content of all lipid fractions studied. Consumption of GLA (2g/day), in the absence of STA or EPA, increased DGLA content with a tendency to increase AA content in some fractions. This effect was prevented by inclusion of EPA in combination with GLA. Thus, this study indicates that STA may be used as a precursor to increase the EPA content of human lipids and that combinations of GLA, STA and EPA can be used to manipulate the fatty acid compositions of lipid pools in subtle ways. Such effects may offer new strategies for manipulation of cell composition in order to influence cellular responses and functions in desirable ways.     

Poly-3-hydroxyalkanoates from marine and freshwater cyanobacteria

Polyesters of (R)-3-hydroxybutanoic and (R)-3-hydroxypentanoic acids have been isolated from Aphanothece species, a freshwater cyanobacteri     

Recombinant production of omega‐3 fatty acids in Escherichia coli using a gene cluster isolated from Shewanella baltica MAC1

Aim: To isolate eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) genes from Shewanella baltica MAC1 and to examine recombinant production of EPA and DHA in E. coli to investigate cost‐effective, sustainable and convenient alternative sources for fish oils. Methods and Results: A fosmid library was prepared from the genomic DNA of S. baltica MAC1 and was screened for EPA and DHA genes by colony hybridization using a partial fragment of the S. baltica MAC1 pfaA and pfaD genes as probes. Analysis of total fatty acids isolated from transgenic E. coli positive for pfaA and pfaD genes by gas chromatography and gas chromatography‐mass spectrometry indicated recombinant production of both EPA and DHA. Analysis of the complete nucleotide sequence for the isolated gene cluster showed 16 putative open reading frames (ORFs). Among those, four ORFs showed homology with pfaA, pfaB, pfaC and pfaD genes of the EPA and/or DHA biosynthesis gene clusters; however, the protein domains of these genes were different from other EPA/DHA biosynthesis genes. Conclusions: The EPA and DHA gene cluster was cloned successfully. The transgenic E. coli strain carrying the omega‐3 gene cluster was able to produce both EPA and DHA. The isolated gene cluster contained all the genes required for the recombinant production of both EPA and DHA in E. coli. Significance and Impact of the Study: These findings have implications for any future use of the EPA and DHA gene cluster in other micro‐organisms, notably those being used for fermentation. Recombinant production of both EPA and DHA by E. coli or any other micro‐organism has great potential to add economic value to a variety of industrial and agricultural products.     

Action of Rice α-Glucosidase on Maltose and Starch

Rice seeds possess α-glucosidase I and II, and the action of the α-glucosidases on maltose and starch was studied. The activity on starch was increased 2.3~2.6 times in both enzymes at the concentration of 50 mM of potassium chloride. Such activation was also caused by mono and di-valent cations. The activity on maltose was not influenced by the cations. In mixed substrate experiments, liberation of ¹⁴C-glucose from ¹⁴C-maltose was not inhibited in the presence of starch, and this was also the case with that from ¹⁴C-starch in the existence of maltose. From these results, it was suggested that the α-glucosidases possess maltose-hydrolyzing site and starch-hydrolyzing site separately, and also probably regulatory. The α-glucosidases liberated only glucose from starch, and were presumed to complete hydrolysis of starch after longer incubation.     

Redox homeostasis is compromised in vivo by the metabolites accumulating in 3-hydroxy-3-methylglutaryl-CoA lyase deficiency in rat cerebral cortex and liver

Abstract

3-Hydroxy-3-methylglutaryl-CoA lyase (HL) deficiency is a disorder biochemically characterized by the predominant accumulation of 3-hydroxy-3-methylglutarate (HMG), 3-methylglutarate (MGA), 3-methylglutaconate and 3-hydroxyisovalerate in tissues and biological fluids of the affected patients. Neurological symptoms and hepatopathy are commonly found in HL deficiency, especially during metabolic crises. Since the mechanisms of tissue damage in this disorder are not well understood, in the present study we evaluated the ex vivo effects of acute administration of HMG and MGA on important parameters of oxidative stress in cerebral cortex and liver from young rats. In vivo administration of HMG and MGA provoked an increase of carbonyl and carboxy-methyl-lysine formation in cerebral cortex, but not in liver, indicating that these metabolites induce protein oxidative damage in the brain. We also verified that HMG and MGA significantly decreased glutathione concentrations in both cerebral cortex and liver, implying a reduction of antioxidant defenses. Furthermore, HMG and MGA increased 2’,7’-dichlorofluorescin oxidation, but did not alter nitrate and nitrite content in cerebral cortex and liver, indicating that HMG and MGA effects are mainly mediated by reactive oxygen species. HMG and MGA also increased the activities of superoxide dismutase and catalase in cerebral cortex and liver, whereas MGA decreased glutathione peroxidase activity in cerebral cortex. Our present data showing a disruption of redox homeostasis in cerebral cortex and liver caused by in vivo administration of HMG and MGA suggest that this pathomechanism may possibly contribute to the brain and liver abnormalities observed in HL-deficient patients.