月腺大戟抑菌活性的初步研究

以小麦赤霉病菌,辣椒疫霉病菌,葡萄黑曲霉病菌,苹果炭疽病和玉米大斑病菌为实验菌种,采用生长速率法测定月腺大戟根部提取物对病原菌菌丝生长的抑制作用.结果表明,月腺大戟根部提取物对5种农作物常见病菌都有抑制作用,其中对3种病原菌(小麦赤霉病菌、苹果炭疽病菌、玉米大斑病菌)的菌丝抑制作用强烈;乙醇相提取物对病原菌抑制作用比水相提取物的抑制活性强.     

紫穗槐种子提取物的抑菌活性研究

目的研究紫穗槐种子提取物的抑菌活性。方法将紫穗槐种子乙醇提取物分别通过石油醚、乙酸乙酯和正丁醇萃取,选择金黄色葡萄球菌和肺炎克雷伯杆菌为供试菌,采用试管二倍稀释法测定紫穗槐种子提取物的最小抑菌浓度（MIC）和最小杀菌浓度（MBC）,涂布平板法绘制杀菌曲线,电镜下观察药物对细菌超微结构的影响。结果紫穗槐种子提取物经乙酸乙酯萃取后对供试菌抑制作用较强,其中对金黄色葡萄球菌的MIC和MBC分别为2．5、5．0mg／mL;对肺炎克雷伯杆菌的MIC和MBC分别为5．0、10．0mg／mL;杀菌曲线结果表明,药物对供试菌的抑制作用存在浓度和时间依赖性;电镜结果说明,药物的作用可能与破坏菌体细胞壁、改变细胞膜通透性有关。结论紫穗槐种子提取物具有显著的抗菌活性。     

枳实提取物及其药效组分对OX—LDL损伤的人脐静脉内皮细胞ICAM-1表达和NO释放的影响

目的：研究枳实提取物及其药效组分橙皮苷和新橙皮苷对氧化低密度脂蛋白（oxidized lowd ensity lipoprotein,Ox—LDL）损伤的人脐静脉内皮细胞（human umbilical vein endothelial cells line,HUVEC）细胞间黏附分子-1（intercellular adhesion molecule-1,ICAM-1）表达和一氧化氮（nitric oxide,NO）释放的影响。方法：体外培养HUVEC,50μg／mLOX—LDL制造HUVEC损伤模型。以MTS染色法检测细胞毒性确定用药浓度。细胞ELISA法测定细胞表面ICAM-1的含量,试剂盒测定细胞培养上清液中NO含量。结果：①枳实提取物小于等于2mg／mL时,橙皮苷浓度小于等于0．03125mg／mL时,新橙皮苷浓度小于等于0．25mg／mL时,HUVEC存活率分别大于80％。②2．0mg／mL和1．0mg／mL两个浓度的枳实提取物、15．625μg／mL的橙皮苷和0．2500mg／mL新橙皮苷对OX—LDL诱导的HUVEC的ICAM-1表达有显著抑制作用。③2．0mg／mL枳实提取物显著提高OX—LDL诱导的HUVEC和正常HUVEC培养液中的NO含量;7．813ixg／mL、15．625μg／mL和31．250μg／mL 3个浓度的橙皮苷能显著提高OX—LDL诱导的HUVEC培养液中的NO含量,31．250μg／mL的橙皮苷能促进正常HUVEC的NO释放;0．2500mg／mL和0．1250mg／mL 2个浓度的新橙皮苷能显著提高OX—LDL诱导的HUVEC培养液中的NO含量。结论：枳实提取物及其药效组分橙皮苷、新橙皮苷能抑制Ox-LDL诱导的HUVEC的ICAM-1表达,促进Ox-LDL诱导的HUVEC的NO释放。     

L型氨基酸对烟草赤星病菌毒素毒性的影响

为确定不同氨基酸对烟草赤星病菌产生的毒素毒性的影响,作者采用摩擦接种处理法、浇根处理法、种子根处理法三种生物测定方法,确定了以烟草种子根处理法作为烟草赤星病菌的毒性测定方法。用12种氨基酸分别以5种不同浓度与AT毒素混合接种,根长测定结果表明：L-谷氨酰胺,L-天冬酰胺,L-组氨酸所有供试浓度均增强病原菌毒素的毒性,而其余9种L型氨基酸对烟草赤星病菌GL-6产生的毒素有抑制作用,其中L-甲硫氨酸、L-亮氨酸、L-赖氨酸适宜浓度可明显降低供试病原菌毒素对烟草的致病性,与对照差异极显著,其有效浓度分别为0．02mg／ml、0．02mg／ml、0．02～2mg／ml。     

多孔板-MTT比色法测定植物抗菌成分对细菌的抑制活性

多孔板-MTT比色法测定植物抗菌成分对细菌抑制活性的步骤为：每孔加入浓度为10^6cfu／mL的供试菌液90灿,然后加入不同浓度的药液10μL,28℃暗培养24h后,每孔中加入5mg／mL的MTT溶液10μL,继续培养4h后加入10％二甲基亚砜100μL,振荡30min,在570nm处测定溶液的吸光值。采用以上方法,测定植物抗菌成分蓝桉醇对辣椒斑点病黄单胞菌（Xanthomonas vesicatoria）和枯草芽孢杆菌（Bacillus subtilis）的半抑制浓度（IC50）分别为0．158和0．395mg／mL,小檗碱对溶血葡萄球菌（Staphylococcus haemolyticus）的IC50为0．587mg／mL。结果表明,多孔板-MTT比色法能快速、微量地测定植物成分对细菌的抑制活性。     

三种植物提取物对菜青虫拒食活性的研究

本文测定了胡椒?葱?川楝子3种植物的石油醚和丙酮提取物对菜青虫3龄幼虫的拒食作用,结果表明,3种供试植物提取物5~40 mg/mL浓度处理24 h对菜青虫幼虫均有一定拒食作用,拒食率达到31.8%~99.8%。其中胡椒的石油醚提取液拒食作用最大,浓度为40 mg/mL的处理效果最好,拒食率达99.8%。总体上看,3种供试植物的石油醚提取物拒食作用大于丙酮提取物,24 h的拒食效果的优于48 h。     

侧柏乙醇提取物对21种植物病原真菌的抑菌活性

采用菌丝生长速率法测定了侧柏(Platycladus orientalis)叶、小枝、球果和种子4个不同部位乙醇提取物对21种植物病原真菌的抑菌活性。结果显示:(1)在供试浓度为50g/L(相当于干样)时,侧柏各部位乙醇提取物对4种供试植物病原真菌均具有较好抑制作用,其中侧柏叶提取物的抑菌效果最好,对供试葡萄白腐病菌(Conio-thyrium diplodiella)、葡萄黑痘病菌(Elsinoe ampelina)、番茄绵腐病菌(Phytophthora melongenae)和青霉病菌(Penicilliu mexpansum)的EC50分别为:5.424、3.186、8.913和19.000g/L。(2)侧柏叶乙醇提取物的石油醚萃取物和乙酸乙酯萃取物抑菌活性均较好,在供试浓度为0.5g/L时,石油醚萃取物对苹果腐烂病菌(Valsa mali)和葡萄黑痘病菌(E.ampelina)的抑菌率分别为80.35%和60.23%;乙酸乙酯萃取物对以上2种植物病原菌的抑菌率分别为81.88%和64.06%。结果表明:侧柏叶、小枝、球果和种子乙醇提取物均具有一定抑菌活性,叶乙醇提取物的活性最好,活性成分主要集中在石油醚萃取物和乙酸乙酯萃取物中。     

迷迭香酸对几种植物病原真菌的抗菌活性*

研究了迷迭香酸对不同植物病原真菌菌丝生长和孢子萌发的抑制活性。试验结果表明,迷迭香酸对供试的8种植物病原真菌菌丝生长均有抑制作用,其中对番茄灰霉病菌、芒果灰斑病菌、柑桔青霉和梨黑斑病菌抑制作用较强,EC50分别为615．04μg/mL、698．23μg/mL、714．50μg/mL和809．10μg/mL;对杉木猝倒病菌和苹果树腐烂病菌抑制作用次之,EC50分别为1039．92μg／mL和1044．72μg/mL;对松枯梢病菌和种实霉烂病菌的抑制作用较弱,EC50分别为1256．90μg/mL和1270．87μg/mL。迷迭香酸对供试的6种植物病原真菌孢子萌发也有明显的抑制作用,EC50大致在400～700μg/mL范围,其中对梨黑斑病菌孢子萌发抑制作用最强,EC50为395．37μg/mL。     

苍耳等48种植物提取物的杀虫活性

采用浸虫法测定了48种植物的丙酮提取物对小菜蛾（Plutella xylostella L．）的杀虫活性,并研究了苍耳（Xanthium sibiricum Patrin．）不同溶剂提取物对小菜蛾和棉蚜（Aphis gossypii Glover）的触杀作用以及苍耳丙酮提取物不同溶剂萃取物对小菜蛾的触杀作用。结果表明,在供试的48种植物中,500g·L^-1黄花蒿（Artemisia annua L）、泽漆（Euphorbia helioscopia L．）、夏至草[Lagopsis supina（Steph．ex Willd．）Ik．-Gal．ex Knorr．]、苍耳及律草[Humulus scandens（Lour．）Merr．]的丙酮提取物对小菜蛾的杀虫活性较强。在苍耳的不同溶剂提取物中,苍耳丙酮提取物的杀虫活性最强,乙醇和乙酸乙酯提取物的杀虫活性次之。另外,50g·L^-1苍耳丙酮提取物的氯仿萃取物对小菜蛾的杀虫活性最强,24h和48h的校正死亡率分别为88．33％和91．67％。     

77种植物提取物对植物病原菌的生长抑制作用

以稻瘟病菌(Pyricularia grisea),水稻恶苗病菌(Fusarium moniliforme),玉米大斑病菌(Exserohilum turci-cum)等12种植物病原菌为供试菌种,采用生长速率法对77种植物的95%乙醇提取物在200μg/mL下进行室内抑菌试验。结果表明有15种植物提取物对植物病原菌有抑制作用,其中华山姜、硬骨藤、龙舌兰、红蒜、大花哥纳香、海南草珊瑚对至少一种菌的抑制率在50%以上,版纳青梅、大果巴戟、华山姜等8种植物提取物对至少三种病原菌均有不同程度的抑制作用。红蒜提取物对百合炭疽病菌、海南草珊瑚提取物对番茄灰霉病菌,以及龙舌兰提取物对玉米大斑病菌的抑制率分别为61.4%、70.7%、76.6%,与阳性对照抑制率相比效果明显。     

Identification and characterisation of the chinese herb Langdu by LC-MS/MS analysis

An LC-MS/MS method has been developed for the identification of three species of herb used as the traditional Chinese medicine Langdu, namely Stellera chamaejasme L., Euphorbia ebracteolata Hayata and E. fischeriana Steud. As these herbs contain different mixtures of marker compounds, they could be unambiguously differentiated from each other by comparing their respective characteristic segmental multiple reaction monitoring profiles. The profiles indicated that S. chamaejasme contained daphnetin, skimmetine, stellerin, chamaechromone and neochamaejasmin, E. fischeriana contained ebracteolata compound B, ingenol, jolkinolide B and fischeriana A, whilst E. ebracteolata contained ebracteolata compounds B and C along with ingenol. These results were confirmed from the respective MS/MS spectra. The method has been successfully applied to differentiate these herbs from the related species Alocasia macrorrhiza (L.) Schott and E. kansui Liou.     

Studies on Active Constituents of Root of Euphorbia ebracteolata Hayata Euphorbiaceae

Seven crystalline constituents were obtained from acidic alcoholic extract of root of Euphorbia ebracteolata. They were identified as octacosanoic acid, daucosterol, β-sitosterol, bis (5-formyl-furfuryl)-ether (Ⅳ), a triterpenic acid, 2,4-dihydroxy-6-methoxyl-3-methyl-acetoph-enone (Ⅵ) and 2-β-glucoside of (Ⅵ) respectively. Three of them (Ⅳ, Ⅴ and Ⅵ) revealed inhibitory effect against tuberculous bacillus..In this paper, the authors reported identification of compound Ⅳ which was found in this plant first time. Its extract has a remarkable effect for the treatment of tuberculosis.     

苍术体外抑菌活性的初步研究

对苍术的体外抑菌活性进行初步的研究。通过用体积分数为50％乙醇浸泡、有机溶剂萃取、薄层层析对苍术抑菌活性物质进行初步分析,用纸片法检测其抑菌活性,用琼脂稀释法测最低抑菌浓度（MIC）。结果表明：苍术提取液对金黄色葡萄球菌的抑菌作用较明显,对白色念珠菌和大肠杆菌的抑菌作用次之,其最低抑茵质量浓度分别为0．7g／mL,1．0g/mL和1．2g/mL;以正丁醇作为萃取液抑菌效果最佳,薄层层析实验结果表明,Rf值为0．76的展开点具有抑菌活性。     

月腺大戟根中乙酰基间苯三酚衍生物

从月腺大戟（Euphorbia ebracteolata Hayata)根中分离出一种新的二苯甲烷化合物－双去甲基伪绵马素－AA和2,4－二羟基－6－甲氧基－3－甲基苯乙酮,并用光谱和化学方法确定前者的结构为3,3－二乙酰基－4,4－二甲氧基－2。25,6－四羟基二苯甲烷     

The lethality of Euphorbia conspicua to adults of Biomphalaria glabrata, cercaria of Schistosoma mansoni and larvae of Artemia salina

Leaf extracts of Euphorbia conspicua (Euphorbiaceae), together with the latex and fractions derived therefrom, were evaluated for their molluscicidal and cercaricidal activities and their toxicities to brine shrimps. Whilst the leaf extracts were inactive against Biomphalaria glabrata, the latex, its triterpenic fraction and irritant fractions I and II exhibited high activities against adult snails with LC90 values of 4.87, 10.55, 0.64 and 0.10 microg/mL, respectively. The latex and its derived fractions were considered lethal to the cercaria of Schistosoma mansoni at concentrations of 100 microg/mL. The toxicities of the latex and the irritant fractions, but not of the triterpenic fraction, against Artemia salina were high with LC50 values < 10 microg/mL. The possible application of the latex of E. conspicua as an alternative natural molluscicide is considered.     

红花寄生叶3种溶剂提取物清除自由基活性

采用4种方法测定了红花寄生(寄主桑树)叶的水、80%甲醇和80%丙酮提取物对自由基的清除活性,以芦丁和BHT为对照品。结果表明,3种提取物均具有较强的自由基清除能力,且表现出不同程度的量效依赖关系;在3种溶剂提取物中,80%甲醇提取物清除.OH和O2-.活性最强,半清除率浓度ρ(SC50)分别为0.212、0.139 mg/mL,而80%丙酮提取物则清除DPPH.和ABTS.+活性最强,ρ(SC50)分别为0.198、0.580 mg/mL。此外,3种溶剂提取物经酸水解后,HPLC均检出槲皮素和山奈酚等2种黄酮醇苷元,其含量范围分别为39.90～73.03 mg/g、4.82～9.19 mg/g间。可见,槲皮素及其苷类衍生物是红花寄生清除自由基活性的主要作用成分。     

LC–MS method for detecting prostratin in plant extracts and identification of a high-yielding population of Euphorbia fischeriana

Prostratin, a tigliane phorbol ester with promise for the treatment of HIV, was identified and quantified in Euphorbia fischeriana root extracts obtained from several different sites in China. The greatest yield was recovered from root samples collected from Yakeshi, Inner Mongolia (63.54 μg/g dry weight, or 0.00635% by mass). Prostratin was not detected in extracts of Euphorbia sp., E. esula, E. lucorum or Stellera chamaejasme. The presence of prostratin was verified by ¹H and ¹³C NMR. Major fragmentation products were identified from ESI MSⁿ spectra after HPLC separation, providing a reproducible fingerprint for unambiguously recognizing the compound in plant extracts.     

Two new flavonol glycosides from Gymnema sylvestre and Euphorbia ebracteolata

Two new flavonol glycosides, namely kaempferol 3-O-beta-D-glucopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-galactopyranoside (1) and quercetin 3-O-6"-(3-hydroxyl-3-methylglutaryl)-beta-D-glucopyranoside (2), have been isolated from the aerial parts of Gymnema sylvestre and Euphorbia ebracteolata, respectively. Their structures were determined on the basis of chemical and spectroscopic methods.     

Larvicidal activities against Aedes aegypti of some Brazilian medicinal plants

Larvicidal activities against Aedes aegypti have been determined in the ethanolic extracts obtained from 51 Brazilian medicinal plants. Eleven of the 84 extracts studied showed significant (LC50 < 100 microg mL(-1)) activities against larvae, with extracts from Annona crassiflora (root bark, LC50 = 0.71 microg mL(-1); root wood, LC50 = 8.94 microg mL(-1)) and Annona glabra (seed, LC50 = 0.06 microg mL(-1)) showing the highest activities. The results obtained should be of value in the search for new natural larvicidal compounds.     

凹叶厚朴抑制α-糖苷酶与抗氧化活性研究

首次采用96微孔板法检测贵州和河南产凹叶厚朴抑制α-葡萄糖苷酶活性;并采用DPPH、ABTS和FRAP三种方法测定其抗氧化活性.贵州产凹叶厚朴乙酸乙酯(IC50 =7.22 μg,/mL)和正丁醇提取部位(IC50=36.59 μg/mL),河南产凹叶厚朴石油醚(IC50=107.04 μg/mL)和乙酸乙酯提取部位(IC50=17.17μg/mL),它们的活性都远高于于阳性对照Acarhose( IC50=1081.27 μg/mL).贵州产凹叶厚朴乙酸乙酯提取部位清除ABTS自由基的能力最强(IC50=8.81 μg/mL),强于阳性对照BHT(IC50=11.94 μg/mL);其次为河南产凹叶厚朴乙酸乙酯提取部位(IC50=12.73 μg/mL).研究结果表明,贵州产凹叶厚朴乙酸乙酯提取部位抑制α-葡萄糖苷酶和抗氧化活性最好.