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1.
Two new homosecoiridoids, named loniaceticiridoside (1) and lonimalondialiridoside (2), were isolated from an aqueous extract of the flower buds of Lonicera japonica. Their structures including the absolute configuration were determined by extensive spectroscopic studies, especially by 2D NMR and CD data analysis. A proposed biosynthetic pathway and preliminary investigations of the biological activity of compounds 1 and 2 are also discussed.  相似文献   
2.
Fourteen sesquiterpenoids with an eudesmane C‐atom skeleton, including four new ones, (1β,5α,7β,8β,11β)‐5‐hydroperoxy‐1‐hydroxyeudesm‐4(15)‐eno‐12,8‐lactone ( 1 ), (1β,5α,7β,8β)‐8‐(acetyloxy)‐5‐hydroperoxy‐1‐hydroxycostic acid methyl ester ( 12 ), and a mixture of (1β,3β,4β,7β,8β)‐1,3‐dihydroxyeudesma‐5,11(13)‐dieno‐12,8‐lactone ( 7 ) and (1β,3β,4β,7β,8β,11β)‐1,3‐dihydroxyeudesm‐5‐eno‐12,8‐lactone ( 8 ), were isolated from the aerial parts of Inula japonica (Asteraceae). Their structures were determined by extensive spectroscopic methods, and those of 7 and 12 confirmed by means of single‐crystal X‐ray diffraction analysis.  相似文献   
3.
Pyrrolizidine alkaloids are highly hepatotoxic natural chemicals that produce irreversible chronic and acute hepatotoxic effects on human beings. Purification of large amounts of pyrrolizidine alkaloids is necessary for toxicity studies. In this study, an efficient method for targeted analysis and purification of pyrrolizidine alkaloid cis/trans isomers from herbal materials was developed for the first time. Targeted analysis of the hepatotoxic pyrrolizidine alkaloids was performed by liquid chromatography with tandem mass spectrometry (precursor ion scan and daughter ion scan), and the purification of pyrrolizidine alkaloids was achieved with a mass‐directed auto purification system. The extraction and preparative liquid chromatography conditions were optimized. The developed method was applied to analysis of Gynura japonica (Thunb.) Juel., a herbal medicine traditionally used for detumescence and relieving pain but is potentially hepatotoxic as it contains pyrrolizidine alkaloids. Twelve pyrrolizidine alkaloids (six cis/trans isomer pairs) were identified with reference compounds or characterized by liquid chromatography with tandem mass spectrometry, and five individual pyrrolizidine alkaloids, including (E)‐seneciphylline, seneciphylline, integerrimine, senecionine, and seneciphyllinine, were prepared from G. japonica roots with high efficiency. The results of this work provide a new technique for the preparation of large amounts of pyrrolizidine alkaloid reference substances, which will also benefit toxicological studies of pyrrolizidine alkaloids and treatments for pyrrolizidine alkaloid‐induced toxicity.  相似文献   
4.
为提高学生探索精神,锻炼学生科学创新思维,培养出更符合社会需要的药学专业型人才,将综合设计性实验的内容引入药物分析实验课程中。以高效液相色谱法测定乌蔹莓中槲皮素、木犀草素的含量,并进行方法学考察为设计任务,通过指导学生查阅资料、设计实验方案、实施实验方案、分析讨论结果,加深学生对基础理论知识的理解;提高学生查阅文献能力、知识扩展能力、自学能力、创新能力等,为就业及深造奠定基础。  相似文献   
5.
Two New Diterpene Alkaloids from the Roots of Spiraea japonica var. Acuta   总被引:1,自引:0,他引:1  
Spiraea japonica L. (Rosaceae) is widely distributed in Yunnan Provence, P. R. China. Previous chemical investigations on S. japonica and its varieties have led to the report of 7 new atisane-type diterpenoids and 38 new diterpene alkaloids of atisine- and hetisine-type1-11. This paper describes the isolation and structure elucidation of two new diterpene alkaloids named spiratines A and B (1-2). Their structures were elucidated on the basis of 1D and 2D NMR experiments (HMQC, HMBC, 1…  相似文献   
6.
1. INTRODUCTION Blood fat primarily contains cholesterol, cholesterol ester, phosphatide, triglyceride and free fatty acid in serum of human being and mammalian. Under physiological conditions, the lipids transport in the form of lipoproteins linked with the proteins. Except for the free fatty acid linked with albumin, the other lipids are linked with the globular proteins into high-density lipoproteins (HDL), low density lipoproteins (LDL), very low density lipoproteins (VLDL) and so…  相似文献   
7.
FGS was isolated and purified from laminaria japonica by enzymolysis,chromatography methods and so on.The high blood fat model was established by feeding mouse on high fat feedstuff.Compared with control group,the concentration of HDL-C.the ratio of HDL-C.TC increased.while the concentration of TC,LDL-C and TG decreased in experimental groups,Conclusion:FGS was an effective serum lipid regulator and can be developed as medicine and health food.  相似文献   
8.
《Electroanalysis》2005,17(4):356-362
Capillary electrophoresis with electrochemical detection (CE‐ED) was employed to analyze active ingredients of Lonicera japonica Thumb., an important crude herb frequently used in Chinese medicines. Hyperoside, chlorogenic acid, luteolin and caffeic acid are the major important active ingredients. Operating in a wall‐jet configuration, a 300 μm diameter carbon‐disk electrode was used as the working electrode, which exhibits a good response at +0.90 V (vs. saturated calomel electrode) for four analytes. Under the optimum conditions, the analytes were baseline separated within 20 min in a 50 mmol L?1 borax buffer (pH 8.7). Notably, excellent linearity was obtained over two orders of magnitude with detection limits (S/N=3) ranging from 0.1 to 0.5 mg L?1 for all the analytes. This method was successfully used in the analysis of Lonicera japonica Thumb. with relative simple extraction procedures, and the assay results were satisfactory.  相似文献   
9.
Five new nonalkaloid constituents, a neolignan, japonin A ( 1 ), a macrocyclic lactone, japonin B ( 2 ), a (phenylethyl)benzoquinone, japonin C ( 3 ), a phenanthraquinone, japonin D ( 4 ), as well as a dihydrostilbene, stilbostemin M ( 5 ), were isolated from the roots of Stemona japonica, together with eight known compounds. Their structures were established by spectroscopic analyses.  相似文献   
10.
建立了高效液相色谱-电喷雾离子阱质谱法(HPLC-ESI-ITMSn)同时测定了金银花中绿原酸和咖啡酸活性成分的分析方法。样品用体积分数80%乙醇回流提取,用Zorbax Eclipse XDB-C18柱分离,以体积分数0.5%甲酸的乙腈-甲酸水溶液为梯度流动相,以保留时间和质荷比对分离出的组分予以定性确证,用峰面积进行定量。绿原酸和咖啡酸的线性范围均为10.0~1000.0μg/L,检出限(以信噪比为3计)均为2.0μg/L。样品的加标平均回收率为92.7%~98.7%,相对标准偏差为1.4%~2.7%。该方法适用于其它复杂体系中绿原酸和咖啡酸的分析。  相似文献   
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