新疆一枝蒿化学成分的研究

目的研究新疆一枝蒿Artemisia rupestris全草的化学成分。方法采用硅胶、聚酰胺和Sephadex LH-20等方法进行分离纯化,采用光谱分析和理化常数对照等方法对所得化合物进行结构鉴定。结果从新疆一枝蒿的醋酸乙酯部分分离得到6个化合物,分别是:6-去甲氧基-4′-O-甲基茵陈色原酮-7-O-[6″-乙酰氧基)-β-D-葡萄糖苷(6-demethoxy-4′-O-methylcapillarisin-7-O-(6″-acetoxy)-β-D-glucopyranoside,]、6-去甲氧基-4′-O-甲基茵陈色原酮-7-O-β-D-葡萄糖苷(6-demethoxy-4′-O-methylcapillarisin-7-O-β-D-glucopyranoside,)、刺槐素-7-O-β-D-葡萄糖苷(acacetin-7-O-β-D-glucopyranoside,)、对羟基苯甲酸(p-hydroxybenzoic acid,)、一枝蒿酮酸(rupestonic acid,)、胡萝卜苷(daucosterol,)。结论其中化合物为新化合物,命名为一枝蒿苷A(rupestriside A),化合物～为首次从该植物中分离得到。     

中药青蒿中青蒿素的脉冲极谱测定法

本文研究用脉冲极谱法测定中药青蒿中青蒿素的含量。青蒿素是从青蒿常见品种黄花蒿中分离得到的抗疟有效成分,结构中有过氧桥,根据过氧桥可还原的性质,能用极谱法测定。本试验选用0.05M硫酸铵为底液,青蒿素于0 V(vs SCE)处出现一良好峰形。浓度在0～6μg/ml范围波高与浓度呈线性关系。测定下限为2μg/ml。生药用石油醚(bp 60～90°)提取后,直接取提取液置极谱池中,挥去石油醚,加2 ml冰醋酸溶解样品,再加入底液进行测定。方法快速、简便、特异,误差在2%以内。     

Inhibitors of inducible nitric oxide synthase expression from<Emphasis Type="Italic">artemisia iwayomogi</Emphasis>

Nitric oxide (NO) is an important bioactive agent that mediates a wide variety of physiological and pathophysiological events. NO overproduction by inducible nitric oxide synthase (iNOS) results in severe hypotension and inflammation. This investigation is part of a study to discover new iNOS inhibitors from medicinal plants using a macrophage cell culture system. Two sesquiterpenes (1 and 2) were isolated from Artemisia iwayomogi (Compositae) and were found to inhibit NO synthesis (IC50 3.64 microg/mL and 2.81 microg/mL, respectively) in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Their structures were identified as 3-O-methyl-isosecotanapartholide (1) and iso-secotanapartholide (2). Compounds 1 and 2 inhibited the LPS-induced expression of the iNOS enzyme in the RAW 264.7 cells. The inhibition of NO production via the down regulation of iNOS expression may substantially modulate the inflammatory responses.     

In vitro antiplasmodial evaluation of medicinal plants from Zimbabwe

In this study the in vitro antiplasmodial activities of extracts from Cussonia spicata (Araliaceae), Artemisia afra, Vernonia colorata, V. natalensis (Asteraceae), Parinari curatellifolia (Chrysobalanaceae), Clutia hirsuta, Flueggea virosa, (Euphorbiaceae), Adenia gummifera (Passifloraceae) and Hymenodictyon floribundum, (Rubiaceae) were evaluated. The lipophilic extracts from the aerial parts of Artemisia afra and Vernonia colorata proved to be the most active against the chloroquine-sensitive strain PoW and against the chloroquine-resistant clone Dd2 of Plasmodium falciparum. Bioassay-guided fractionation of the extract of A. afra yielded seven flavonoids, from which acacetin, genkwanin and 7-methoxyacacetin showed in vitro activity; the IC(50) values ranged from 4.3 microgram/mL to 12.6 microgram/mL. In addition, several sesquiterpene lactones could be obtained from the most active fractions. Whereas eudesmaafraglaucolide proved to be inactive, the guaianolides 1-desoxy-1alpha-peroxy-rupicolin A-8-O-acetate, 1alpha,4alpha-dihydroxybishopsolicepolide and rupicolin A-8-O-acetate revealed in vitro antiplasmodial activity. Evaluation of V. colorata gained four sesquiterpenes 11beta,13-dihydrovernodalin, vernodalol, 11beta,13-dihydrovernolide and 11beta,13,17,18-tetrahydrovernolide, from which the first two constituents exhibited the strongest antiplasmodial activity (IC(50) values: 1.1-4.8 microgram/mL).     

青蒿素提取条件研究

以干青嵩味末为原料，分别用乙醚、氯仿、正己烷、石油醚搅拌提取青蒿素，结果表明石油醚是较适宜的提取介质。对石油醚提取青蒿素的工艺条件，如温度、时间、溶剂及搅拌速度等进行了较系统研究，确定了较佳的工艺操作条件。     

油蒿和柠条水分限制的种间竞争模型

目的　为充分有效地利用水资源，稳定人工生态系统提供科学依据。方法　以油蒿和柠条为研究对象， 组建数学模型。结果　建立了油蒿、柠条在水分限制下的种间竞争模型：ｄ Ｎ１ｄｔ ＝ ｒ１ Ｎ１（ Ｋ１ － Ｎ１ － αλ２ Ｋ１ｒ１ ｖｖ１ Ｎ２ Ｋ１ ） ；ｄ Ｎ２ｄｔ ＝ ｒ２ Ｎ２（ Ｋ２ － Ｎ２ － βλ１ Ｋ２ｒ２ ｖｖ２ Ｎ１ Ｋ２ ） 。结论　油蒿与柠条之间实现着既竞争又稳定共存的格局。     

青蒿明胶丸的抗疟作用研究

明胶丸对小鼠的LD_(50)剂量为162.5±10.1g(生药)/kg,对伯氏敏感株鼠疟原虫的半数转阴剂量ED_(50)为11.9±2.4g(生药)/kg,化疗指数为13.6,明胶丸的抗疟效价比青蒿素大3.5倍;对鼠疟、人间日疟的治愈率为100％,与青蒿浸膏、氯喹相同;退热时间及转阴时间均快于氯喹,但近期复燃仍较高,当延长服药天数至6d,增加日服药次数至4次或与伯氨喹伍用,可显著降低近期复燃率。该制剂生产成本大大低于青蒿素,服药量及毒副反应小于青蒿浸膏片,易于推广,病人乐于接受。     

黄花蒿的化学成分研究进展

黄花蒿为传统中药,具有清热解毒、除蒸截疟的功效.近年来采用现代中药研究方法,如HPLC、GC-MS、LC-MS等从黄花蒿中分离出多种有效成分.黄花蒿的化学成分主要有倍半萜类、黄酮类、香豆素类和挥发油类,其中倍半萜类和甲氧基黄酮类成分较为丰富,且甲氧基黄酮类对黄花蒿的抗疟活性具有促进作用.     

青蒿中樟脑龙脑和异龙脑的含量测定

目的:测定青蒿中樟脑、龙脑、异龙脑含量.方法:采用毛细管气相色谱法,HP-5石英毛细管柱(30 m×0.25 mm×0.25 m);FID检测器;程序升温.结果:樟脑、龙脑、异龙脑进样量分别在0.196～9.82 ng、0.139～6.94 ng、0.0596～2.98 ng范围内有良好线性关系.平均回收率分别为99.0％、99.0％和98.7％.结论:本方法简单、准确,重复性好,可用于青蒿药材樟脑、龙脑、异龙脑的含量测定.