Study on Chemical Constituents of Swertia verticillifolia

Eight compounds have been isolated from Swertia verticillifolia by means of silica-gel column chromatography. Their structure have been identified as 1,5,8-trihydroxy-3-methoxyxanrhone(Ⅰ); 1,3,5,8-tetrahylroxyxanthone(Ⅱ);1,3,7,8-tetrahydroxyxanthone(Ⅲ);8-O-B-D-glu-copyranosyl-1, 5-dihydroxy-3-methoxyxanthone(Ⅳ);8-O-B-D-glucopyranosyl-l,3,5-trihydro-xyxanthone(Ⅴ); 1-O-B-D-glucopyranosyl-3, 8-dihydroxy-7-methoxyxanthone (Ⅵ); ursolic acid (Ⅶ) and B-sitosterol(Ⅷ), on the basis of UV, IR, NMR analyses and chemical methods.     

Studies on the Chemical Constituents of Rhodiola fastigita S. H. Fu

Rhodiola fastigita is an alpine plant growing at 3300--5400 m above sea level. Seven crystal, compounds were isolated from the rhizome of this plant. They were identified as β- sitosterol, β-sitosterol-3-β-D-galactoside, daucosterol, gallic acid, gallic acid ethyl ester, p-tyrosol and herbacetin-8-arabinoside by IR, MS, H-NMR and chemical method. Daucosterol, β-sitosterol- 3-β-D-galactoside and gallic acid ethyl ester were obtained from the genus Rhodiola L. for the first time.     

诺丽青果化学成分研究

干燥诺丽青果粉末95％乙醇提取物的正丁醇萃取部分经硅胶、Sephadex LH-20和LiChmprep RP-18等材料分离,波谱学方法鉴定了8个化合物,分别为乌苏酸（1）、6,7-二羟基香豆素（2）、胡萝卜甙（3）、车叶革甙（4）、Borreriagenin（5）、去乙酰车叶草甙（6）、O-β-D-glucopyranoside scopolln（7）、车叶草酸（8）。其中化合物7为首次从该种中分到。     

Effects of acetyl-L-carnitine on the formation of fatty acid ethyl esters in brain and peripheral organs after short-term ethanol administration in rat

Increasing evidence suggests that Fatty acid ethyl esters (FAEE) play a central role in ethanol induced organ damage. In the current study we measured FAEE formation in rats after short-term oral administration of ethanol, in the presence and absence of pre-treatment with acetyl-L-carnitine. Ethanol treatment caused a significant increase in the levels of FAEE, particularly in the brain and heart, but also in the kidney and liver. Increases in FAEE were associated with a significant increase in FAEE synthase activity, GSH transferase activity, and lipid hydroperoxide levels. Pre-treatment with acetyl-L-carnitine resulted in a significant reduction of FAEE accumulation, decrease in FAEE synthase and GSH transferase activities, and lipid hydroperoxide levels. Administration of acetyl-L-carnitine greatly reduced the metabolic abnormalities due to non-oxidative ethanol metabolism, through an increment in lipid metabolism/turnover and by the modulation of the activities of enzymes associated with FAEE synthesis. These results suggest a potentially important pharmacological role for acetyl-L-carnitine in the prevention of alcohol-induced cellular damage.     

Odoriferous compounds from the flowers of the conifers Picea abies,pinus sylvestris and Larix sibirica

A GC/MS analysis of the volatile constituents from the flowers of Norway Spruce, Picea abies, has been carried out. The volatile constituents of the female flowers were distinctly different from those of the male flowers and the twigs. Characteristic constituents are methyl and ethyl benzoate, methyl and ethyl salicylate, methyl and ethyl butanoate, borneol and bornyl acetate. In the scent from the male flowers we could only detect the same monoterpenes as in the twigs. In Larix sibirica methyl benzoate, methyl salicylate, borneol and bornyl acetate were detected in the female flowers and, in the female flowers of Pinus sylvestris, methyl salicylate was found.     

扁桃叶的化学成分研究

从芒果属植物扁桃(Mangifera persiciformis C.Y.Wu et T.L.Ming)叶乙醇提取物乙酸乙酯萃取部位中分离得到7个化合物,经波谱鉴定为没食子酸甲酯(1),没食子酸(2),3,4-二羟基苯甲酸(3),槲皮素(4),山奈酚-3-O-β-D-葡萄糖苷(5),槲皮素-3-O-β-D-葡萄糖苷(6)和芒果苷(7).其中化合物1、3、5、6为首次从该植物中分离得到.     

Chemical Constituents from Fruits of Rosa davidii

From the fruit of Rosa davidii Crep., eleven compounds were isolated and identified by spectral evidence, viz. 2α,3β,19β-trihydroxyl-olean-12-en-28-oic acid (1), 2α,3β-dihydroxyl-urs-28(13)-lactone (2), arjunic acid (3), euscaphic acid (4), 2α,3β-dihydroxyl-urs-12-en-28-oic acid (5), oleanolic acid (6), kaempferol (7), tiliroside (8), quercetin (9), daucosterol (10) and β-sitosterol (11). Among them, 1 and 2 were new compounds.     

桂火绳中化学成分的研究

从梧桐科火绳属桂火绳中提取分离到22个化合物,经结构鉴定为:羽扇豆醇(1),白桦脂酸(2),齐墩果酸(3),丁香脂素(4),(+)-异落叶松树脂醇(5),东莨菪内酯(6),对羟基肉桂酸(7),二十七碳酸单甘油酯(8),2-十八烯酸单甘油酯(9),sitoindosideⅡ(10),儿茶素(11),表儿茶素(12),表儿茶素3-O-β-D-吡喃木糖甙(13),山奈酚3-O-β-D-吡喃葡萄糖甙(14),5,7,4'-三羟基异黄酮(15),4'-O-methylgallocatechin(16),反式-二氢槲皮素-3-O-α-阿拉伯糖甙(17),顺式-二氢槲皮素-3-O-α-阿拉伯糖甙(18),反式-二氢槲皮素-3-O-β-吡喃葡萄糖甙(19),3,5,7,3',5'-五羟基-4'-甲氧基异黄酮(20),山奈酚-3-O-β-D-吡喃葡萄糖(6→1)-α-L-吡喃鼠李糖甙(21),以及槲皮素3-O-β-D-吡喃葡萄糖(6→1)-β-D-吡喃葡萄糖甙(22),这些化学成分首次从该属植物中分离出来。     

沉水植物苦草化学成分研究

通过使用乙酸乙酯溶剂对沉水植物苦草（Vallisneria natans）全草进行超声连续提取,采用硅胶柱色谱法和光谱分析法分离和鉴定化学成分。从苦草中分离到6个化合物：6,10,14-三甲基-2-十五酮（1）、棕榈酸（2）、4,22-二烯-3β-豆甾酮（3）、5α,豆甾烷-3,6-二酮（4）、硬脂酸（5）、棕榈酸乙酯（6）。化合物1—6为首次从该植物中发现。     

Studies on the Chemical Constituents of Bretschneidera sinensis Hemsl. EndEmic in China

Four compounds were for the first time isolated from trunk of Bretschneidera sinensis Hemsl. grown in Yunnan. They were identified as 3-epi-betulinic acid(l), 3,5,7-tri-hydroxy-flavanonol (pinobanksin) (2), daucosterol (3) and β-sitosterol (4), respectively by chemical and spectral (IR, NMR, and MS) analyses. 1 and 2 were the main components.     

国产人工打洞沉香的化学成分研究

为了解国产人工打洞方法所结沉香的化学成分,从国产人工打洞沉香的乙酸乙酯提取物中分离得到8个化合物,经波谱分析分别鉴定为:5-羟基-7,4′-二甲氧基黄酮(1)、3-羟基-4-甲氧基-苯丙酸甲基酯(2)、姜油酮(3)、对甲氧基苯丙酸(4)、正三十二烷醇(5)、(20R)-24-ethylcholest-4-en-3-one(6)、麦角-4,6,8(14),22-四烯-3-酮(7)、豆甾醇(8)。化合物1,2,4~8均为首次从沉香中分离得到的化合物。抗菌活性表明化合物3对金黄色葡萄球菌(Staphylococcu aureus)和烟草青枯菌(Ralstonia solanacearum)均有抑制作用,化合物7仅对烟草青枯菌具有抑制作用。     

优化硫酯酶表达提高大肠杆菌脂肪酸乙酯的生物合成效率

利用基因工程大肠杆菌直接从头生物合成脂肪酸乙酯 (生物柴油) 的相关研究引起了国内外研究人员的广泛关注。在本课题组已经构建的能够从头合成脂肪酸乙酯的大肠杆菌菌株KC3的基础上,通过替换表达不同来源的硫酯酶,发现表达来源于香樟树的硫酯酶Cc FatB1基因能够提高脂肪酸乙酯产量。进一步通过共表达Cc FatB1和大肠杆菌硫酯酶tesA’基因,以及启动子优化,获得了高产脂肪酸乙酯工程菌株KC4。KC4菌株在摇瓶条件和发酵条件下的单位生物量脂肪酸乙酯产率分别为21.4 mg/ (L?OD600)和31.16 mg/ (L?OD600)。该工程菌株的构建进一步提高了脂肪酸乙酯产量,显示了通过基因工程改造大肠杆菌从头合成生物柴油的应用潜力。     

3β-hydroxy-21β-e-cinnamoyloxyolean-12-en-28-oic acid,a triterpenoid from enterolobium contorstisiliquum

The triterpenes 3β-hydroxy-21β-E-cinnamoyloxyolean-12-en-20-oic acid, 3β,21β-dihydroxyolean-12-en-28-oic acid (machaerinic acid) and its lactone (3β-hydroxyolean-12-en-21β→28-lactone) were isolated from the fruits of Enterolobium contorstisiliquum. Methyl and ethyl esters of 3β,21β-dihydroxyolean-12-en-oic acid were isolated and characterized as artifacts. The structures of these triterpenes have been established by a study of their chemical and spectroscopic (IR, MS and NMR) data.     

Synthesis of FAEEs from glycerol in engineered Saccharomyces cerevisiae using endogenously produced ethanol by heterologous expression of an unspecific bacterial acyltransferase

The high price of petroleum-based diesel fuel has led to the development of alternative fuels, such as ethanol. Saccharomyces cerevisiae was metabolically engineered to utilize glycerol as a substrate for ethanol production. For the synthesis of fatty acid ethyl esters (FAEEs) by engineered S. cerevisiae that utilize glycerol as substrate, heterologous expression of an unspecific acyltransferase from Acinetobacter baylyi with glycerol utilizing genes was established. As a result, the engineered YPH499 (pGcyaDak, pGupWs-DgaTCas) strain produced 0.24 g/L FAEEs using endogenous ethanol produced from glycerol. And this study also demonstrated the possibility of increasing FAEE production by enhancing ethanol production by minimizing the synthesis of glycerol. The overall FAEE production in strain YPH499 fps1Δ gpd2Δ (pGcyaDak, pGupWs-DgaTCas) was 2.1-fold more than in YPH499 (pGcyaDak, pGupWs-DgaTCas), with approximately 0.52 g/L FAEEs produced, while nearly 17 g/L of glycerol was consumed. These results clearly indicated that FAEEs were synthesized in engineered S. cerevisiae by esterifying exogenous fatty acids with endogenously produced ethanol from glycerol. This microbial system acts as a platform in applying metabolic engineering that allows the production of FAEEs from cheap and abundant substrates specifically glycerol through the use of endogenous bioethanol.     

Long-chain fatty acids and ethanol affect the properties of membranes inDrosophila melanogaster larvae

The larval fatty acid composition of neutral lipids and membrane lipids was determined in three ethanol-tolerant strains ofDrosophila melanogaster. Dietary ethanol promoted a decrease in long-chain fatty acids in neutral lipids along with enhanced alcohol dehydrogenase (EC 1.1.1.1) activity in all of the strains. Dietary ethanol also increased the incorporation of¹⁴C-ethanol into fatty acid ethyl esters (FAEE) by two- to threefold and decreased the incorporation of¹⁴C-ethanol into free fatty acids (FFA). When cultured on sterile, defined media with stearic acid at 0 to 5 mM, stearic acid decreased ADH activity up to 33%. In strains not selected for superior tolerance to ethanol, dietary ethanol promoted a loss of long-chain fatty acids in membrane lipids. The loss of long-chain fatty acids in membranes was strongly correlated with increased fluidity in hydrophobic domains of mitochondrial membranes as determined by electron spin resonance and correlated with a loss of ethanol tolerance. In the ethanol-tolerant E2 strain, which had been exposed to ethanol for many generations, dietary ethanol failed to promote a loss of long-chain fatty acids in membrane lipids. We are grateful for the support of National Institutes of Health Grant AA06702 (B.W.G.) and National Science Foundation Grant CHE-891987 (R.G.K.).     

Effects of root hypoxia and a low P supply on relative growth, carbon dioxide exchange rates and carbon partitioning in Pinus serotina seedlings

The present study was conducted to determine how 10 weeks of root hypoxia and a low P supply altered relative growth, and carbon acquisition and partitioning in a moderately flood tolerant pine. Pond pine (Pinus serotina Michx.) seedlings were grown in continuously flowing solution culture at 5 or 100 μM P, under aerobic or hypoxic solution conditions. Staggered harvests were used to ascertain changes in biomass allocation and relative growth over time. Carbon dioxide exchange rates (CER) were determined by infrared gas analysis, and needles were analyzed for inorganic P (Pi), sucrose, reducing sugars and starch. Although aeration treatment had no significant effect on shoot dry weight or shoot ontogeny, root dry weight of hypoxic seedlings was significantly lower than that of aerobic seedliings after 8 weeks, regardless of the P treatment. Mean relative growth rates (RGR) of roots in the high P treatment initially decreased under hypoxia, but recovered by the sixth week with the production of adventitious roots. Two weeks of hypoxic growth conditions decreased CER and stomatal conductances of seedlings in the high P treatment by more than 30% relative to their aerobic counterparts. Stomatal closure was not accompanied by a decrease in intracellular CO₂, but was accompanied by an increase in starch accumulation. Recoveries of CER, stomatal conductance and carbohydrate metabolism coincided with the recovery of root growth. Low P growth conditions did not significantly affect shoot or root dry weight until the sixth week of treatment. However, differences in seedling RGR, particularly needle RGR, were discernable during the first 2 weeks. Low P treatment effects on CER paralleled changes in needle RGR, with needle RGR more affected than CER. After 6 weeks, CER of aerobically grown seedlings in the low P treatment were only 15% lower than CER of seedlings in the high P treatment, despite a 31% and 75% reduction in needle RGR and Pi concentrations, respectively. Increased starch concentrations of recently expanded needles at this time were probably a result of diminished growth. The inhibitory effect of a low P supply on shoot growth, more specifically on needle expansion and emergence of new fascicular needles, probably limited net carbon fixed per plant more than any direct effect of low P on CER per se.     

Studies on the Chemical Constituents of Duzhong (The Bark of Eucommia ulmoides Oliv.)

Four constituents were isolated from the bark of Eucommia ulmoide; Oliv. Based on the physico-chemical constants, spectral analysis and properties of derivatives, they were identified as: liriodendrin (1), geniposidic acid (2), (+)-pinoresinol di-O-β-D-glucopyranoside (3), and daucosterol.     

Biomarkers for detection of prenatal alcohol exposure: a critical review of fatty acid ethyl esters in meconium

BACKGROUND: The objective of this study was a review of published studies utilizing measurement of fatty acid ethyl esters (FAEE) in meconium as biomarkers for prenatal alcohol exposure. METHODS: We completed a literature search of PubMed using the terms meconium, fatty acid ethyl esters, biomarkers, and prenatal alcohol exposure. We included only peer reviewed studies utilizing analysis of meconium for the presence of FAEE in humans through the year 2007. RESULTS: We found 10 articles reporting on original research examining the relationship of FAEE from meconium and prenatal alcohol exposure (PAE). The 10 articles used six different PAE assessment strategies and four different analytical techniques for determining FAEE endpoints. The articles included 2,221 subjects (range 4 to 725) with 455 (20.5%) subjects identified as exposed using the methods stated in the articles. FAEE levels above the studies' respective cutoffs were reported for 502 (22.6%) subjects. CONCLUSIONS: The accurate identification of alcohol‐exposed pregnancies represents a significant challenge in the development of FAEE detection cutoffs to maximize the sensitivity and specificity of the test. We present several options for the improvement of exposure assessment in future studies of FAEE as biomarkers for PAE. Birth Defects Research (Part A), 2008. © 2008 Wiley‐Liss, Inc.     

藏药提宗龙胆花的化学成分研究

从传统藏药提宗龙胆(Gentiana tizuensisFranch.)花的乙醇提取物中分离得到3个化合物,利用波谱方法鉴定为熊果酸(ursolic acid,1)、异荭草苷(isooreintin,2)、日本獐牙菜素(swertiajaponin,3).其中,化合物2为首次从该植物中发现,化合物3为龙胆属植物中首次发现.