新疆桑叶中挥发油化学成分的GC/MS分析

目的:建立一种新疆桑叶中挥发油的化学成分分析的方法。方法:采用乙醚超声萃取-水蒸气蒸馏的方法提取桑叶中的挥发油,用气相色谱-质谱法对桑叶中挥发油的化学成分进行了分析。共分离出80余峰,鉴定出了55种物质,占挥发油总成分的90%以上。用面积归一化法确定了各组分的相对含量。结果:所分离出的化合物中含有烷烃(C10~C40)、烯烃、不饱和醇、不饱和醛、不饱和酮、羧酸、酯、杂环化合物及芳香族化合物。主要成分为正十八烷(9.11%)、邻苯二甲酸二(2-甲基)丙酯(8.92%)和3,7,11,15-四甲基-2-十六碳烯-1-醇(7.19%)。挥发油中还含有少量的萜类化合物。结论:本方法稳定可靠,重现性好,适用于中药挥发油的化学成分分析。     

辣木叶多糖的提取及分离纯化

对辣木叶多糖的提取工艺、分离纯进行了研究。结果表明:辣木叶多糖的最佳提取工艺为:温度80℃,料液比1∶20,时间1.5 h,提取次数3次;最佳提取条件下粗多糖得率达到15.86%。经脱蛋白、脱色、DEAE-52纤维素柱和Sephadex G-100柱层析,纯化得PSM2-1和PSM2-2两个多糖组分。为辣木叶多糖的深入研究提供了基础。     

黄精根茎及须根中相关成分的分析

目的：黄精根茎与须根相关成分分析。方法：薄层层析法检测。结果：南京地区典精中含有多糖，几乎不含黄酮、蒽醌类化合物。结论：根茎与须根成分基本相同。     

Studies on the Chemical Constituents of Epimedium koreanum Nakai and Epimedium wanshanense,S.Z.He et Guo

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Modulation of MPP<Superscript>+</Superscript> uptake by tea and some of its components in Caco-2 cells

The entry of most xeno/endobiotics into the organism is limited by their intestinal absorption. The interference of certain foods with the therapeutic efficacy of drugs or with chemical toxicity is becoming evident and growing attention is being given to these subjects. The aim of this work was to study the effect of green tea (GT) and black tea (BT), as well as some of their components, on the transport of organic cation molecules. For this purpose, ³H-MPP⁺ (radiolabeled 1-methyl-4-phenylpyridinium) was used as a model organic cation and Caco-2 cells were used as an intestinal epithelial model. Our results showed that both GT and BT significantly increased ³H-MPP⁺ absorption in these cells. Additionally, we studied the effect of epigallocatechin-3-gallate (EGCG), myricetin, caffeine, and theophylline. Whereas EGCG (2 mM) increased, myricetin (50 μM) and caffeine (1 mM) decreased, and theophylline (1 mM) had no effect on the uptake of ³H-MPP⁺ into Caco-2 cells. When GT was supplemented with caffeine or theophylline, we observed a partial loss of its effect. When BT was supplemented with EGCG, its ability to increase ³H-MPP⁺ uptake was much more pronounced than that observed with BT alone. In conclusion, this study showed that GT and BT might interfere with the absorption of the model organic cation MPP⁺ by the intestinal epithelium. Since important compounds are organic cations, the consequences of this interference may have an impact on human health. Although this constitutes only preliminary work and further studies are needed, tea should be included in the growing list of foodstuffs that have the potential to be involved in food–drug interactions.     

Potential role of flavonoids in the prevention of intestinal neoplasia: a review of their mode of action and their clinical perspectives

Intestinal neoplasia (adenomas and carcinomas) can possibly be prevented by a diet rich in vegetables and fruits, treatment with aspirin and other nonsteroidal antiinflammatory drugs, and early colonoscopic removal of adenomas. Ballast, fiber, and secondary plant products could play a major role in colon cancer prevention. Recently there has been much experimental work in vitro and in vivo about flavonoids as inducers of bioprevention. Flavonoids are secondary plant products with a wide variety of beneficial biological properties, and they possess anticarcinogenic, antimutagenic, and antioxidative modes of actions. Flavonoids are the main components of a healthy diet containing fruits and vegetables and are concentrated especially in tea, apples, and onions. We will focus this review on flavonoids which are derived from tea products such as proanthocyanidins (green tea) and flavons (camomille tea). Oral supplementation with bioflavonoids derived from tea could be used in humans to prevent growth of intestinal neoplasia such as adenomatous polyps of the colon. Flavonoids are a large group of natural compounds of which only a few have been used in animal models, cell cultures, and enzyme studies to inhibit mutagenic and carcinogenic events. Their clinical mode of action was evaluated by epidemiological studies, but no intervention studies in humans have been performed so far. In vitro flavonoids can bind electrophils, inactivate oxygen radicals, prevent lipid peroxidation, and inhibit DNA oxidation. In cell cultures they increase the rate of apoptosis, inhibit cell proliferation, and angiogenesis. In vivo they can induce the activities of protective enzymes (conjugating enzymes such as glutathione transferases and glucuronosyl transferases) of the intestine and the liver. In models of intestinal polyposis, flavonoids suppress polyp formation. Some epidemiological studies show a protective effect of flavonoids contained in fruits, vegetables, and tea.Flavonoid mixtures of tea origin supplied as nutritional supplements could be studied as a new way of bioprevention of intestinal neoplasia (colon adenomas and cancer). Therefore, a controlled, randomized clinical study should be performed to evaluate the efficacy of flavonoids.     

Antimycobacterial activity and cytotoxicity of flavonoids from the flowers of<Emphasis Type="Italic">Chromolaena odorata</Emphasis>

From the flowers of Chromolaena odorata (Eupatorium odoratum) four flavanones, isosakuranetin (5,7-dihydroxy-4'-methoxyflavanone) (1), persicogenin (5,3'-dihydroxy-7,4'-dimethoxyflavanone) (2), 5,6,7,4'-tetramethoxyflavanone (3) and 4'-hydroxy-5,6,7-trimethoxyflavanone (4), two chalcones, 2'-hydroxy-4,4',5',6'-tetramethoxychalcone (5) and 4,2'-dihydroxy-4',5',6'-trimethoxychalcone (6), and two flavones, acacetin (5,7-dihydroxy-4'-methoxyflavone) (7) and luteolin (5,7,3',4'-tetrahydroxyflavone) (8) were isolated and identified. Compound 1 exhibited moderate antimycobacterial activity against Mycobacterium tuberculosis with the MIC value of 174.8 microM, whereas compounds 4, 7, and 8 exhibited weak activity with the MIC values of 606.0, 704.2 and 699.3 microM respectively. Compound 7 showed moderate cytotoxicity against human small cell lung cancer (NCI-H187) cells with the MIC value of 24.6 microM, whereas compound 8 exhibited moderate toxicity against NCI-H187 cells and week toxicity against human breast cancer (BC) cells with the MIC values of 19.2 and 38.4 microM respectively.     

Phytochemical constituents from<Emphasis Type="Italic">diodia teres</Emphasis>

All ten compounds were isolated from the methanolic extract of the whole plants of Diodia teres through repeated silica gel and Sephadex LH-20 column chromatography. Their chemical structures were elucidated as three iridoid glycosides, asperuloside, geniposidic acid and asperulosidic acid, a coumarin glycoside, scopolin, and six flavonoids, rutin, kaempferol-3-O-rutinoside, quercitrin, astragalin, isoquercitrin and quercetin by spectroscopic analysis.     

Flavonol and Flavone Intake and the Risk of Intermittent Claudication in Male Smokers

The objective of this study was to investigate the association between flavonol and flavone intake and the risk of intermittent claudication in male smokers. The study population consisted of participants of the Finnish alpha-Tocopherol, beta-Carotene Cancer Prevention (ATBC) Study, who were free of intermittent claudication at study entry. These 25,041 male smokers were 50-69 years old at baseline. Participants completed a validated dietary questionnaire at baseline. The occurrence of intermittent claudication was assessed by annual administration of the Rose questionnaire. During the median follow-up of 4.1 years, 2412 new cases of intermittent claudication were observed. Dietary intake of flavonols and flavones was inversely associated with the risk of intermittent claudication when adjusted for cardiovascular risk factors (relative risk, RR in the highest vs. lowest quintile of intake 0.86, 95% confidence interval, CI: 0.75-0.98, p for trend 0.007). However, after further adjustment for intakes of vitamins C and E and total carotenoids, the association was attenuated (RR: 0.93, 95% CI: 0.81-1.08, p for trend 0.12). The risk of intermittent claudication was lower among men in the highest quintile of vegetable consumption (RR: 0.78, 95% CI: 0.69-0.89, p for trend 0.0001) and among wine drinkers (RR: 0.63, 95% CI: 0.41-0.98). Adjustment for flavonol and flavone intake only marginally changed these associations. In conclusion, flavonol and flavone intake was not independently associated with the risk of intermittent claudication.     

Flavonoids from the seeds of Sphaerophysa salsula

Two new flavonoids, named sphaerophyside SA and sphaerophyside SB, together with 15 known flavonoids were isolated from the ethanolic extract of the seeds of Sphaerophysa salsula (Pall.) DC. The structures of the new compounds were elucidated mainly on the basis of the 1D and 2D NMR data.