铃兰族的甾体皂甙

铃兰族植物富含甾体皂甙,本文对该族植物中甾体皂甙的化学结构、分布及生物活性进行了综述。     

白穗花的甾体皂甙

从中国特有植物白穗花（Speiranthagardenii（Hook．）Baill．）根茎中分离得到两个新的甾体皂甙。经化学和光谱方法鉴定其化学结构分别为22－甲氧基－（25R）－5β－呋喃甾烷－1β,3β,4β,5β,26-五羟基26－O-β-D-吡喃葡萄糖甙（Ⅰ）和22-甲氧基-（25R）－5β-呋喃甾烷-1β,2β,3β,4β,5β,26-六羟基26－O－β-D-吡喃葡萄糖甙（Ⅱ）。     

铃兰族的甾体皂甙

铃兰族植物富含甾体皂甙,本文对该族植物中甾体皂甙的化学结构、分布及生物活性进行了综述。     

乐山蜘蛛抱蛋的甾体皂甙

乐山蜘蛛抱蛋;;蜘蛛抱蛋皂甙;;铃兰皂甙元Ｂ－５－Ｏ－β－Ｄ－吡喃葡萄糖甙     

龙血树果实的甾体皂甙成分

从龙血树(Dracaena cambodiana Pierre et Gagn.)的新鲜果实中分离到四个甾体皂甙,分别鉴定为薯蓣皂甙(dioscin)、22-甲基原薯蓣皂甙(22-methy proto-dioscin),纤细薯蓣皂甙(gracillin)和22-甲基原纤细薯蓣皂甙(22-methy proto-gracillin),龙血树中富含薯蓣皂甙元(diosgenin)的配糖体表明龙血树科作为天门冬目的一个成员,在亲缘关系上与龙舌兰科和天门冬科最为接近,与玉簪科、菝葜科以及薯蓣目亦有密切的联系。     

海星中的皂甙和多羟基甾体化合物

海洋无脊椎动物海星的次级代谢产物以皂甙和多羟基甾醇为主,且多具有明显的生理活性。本文综述了近十年来海星中皂甙和多羟基甾体化合物的研究进展。     

四川蜘蛛抱蛋的甾体皂甙

从四川蜘蛛抱蛋（Ａｓｐｉｄｉｓｔｒａ ｓｉｃｈｕａｎｅｎｓｉｓ Ｋ。Ｙ。Ｌａｎｇ ｅｔ Ｚ。Ｙ。Ｚｈｕ）根状茎中分离得到三个甾体皂甙,经光谱和化学方法分别鉴定为２２－甲氧基－５β－呋喃甾烷－１β,３β,４β,５β,２６－五羟基２６－Ｏ－β－Ｄ吡喃葡萄糖甙（１）,蜘蛛抱蛋皂甙（２）和原蜘蛛抱蛋皂甙（３）。（１）是一个呋喃甾醇型单糖链的新皂甙,（３）是本植物的主要皂甙。     

五种开口箭属植物根状茎中甾体皂甙及甾体皂甙元的初步研究

薄层层析结果显示五种开口箭属植物根状茎中均含有甾体皂甙和甾体皂甙元 ,为开口箭属植物作为甾体药物资源提供了依据。     

甾体皂甙的生物合成

近年来,人们分离鉴定了许多结构新颖的皂甙,阐明了它们的结构及生物活性,并对甾体皂甙的生物合成途径进行了较为深入的研究。异戊烯二磷酸在香叶二磷酸合成酶、法呢二磷酸合成酶、鲨烯合成酶和鲨烯环氧酶催化下合成2,3-环氧化鲨烯,再经环氧化鲨烯环化酶催化下形成三萜进而转化成甾醇,甾醇经羟化酶、糖基转移酶和β-糖苷酶的修饰,形成各种类型的甾体皂甙。本文重点介绍了甾体皂甙生物合成中所需要的关键酶,特别是以往研究较少的糖酶,主要为3-O-糖基转移酶,26-O-β-糖苷酶,并对甾体皂甙生物合成的前景进行了展望。     

浙江山萆薢甾体皂甙的研究

从山萆薢根茎分到6个甾体皂甙,通过乙酰化、酸水解,红外、质谱和碳谱等鉴定,分别为约诺皂甙(A),薯蓣皂甙(C),纤细皂甙(D),原薯蓣皂甙(E),原纤细皂甙(F);皂甙 B 因得率极低,未能完成鉴定。     

滇重楼地上部分的两个微量皂甙

从滇重楼地上部分中分离出两个新的微量的甾体皂甙ＰｏｌｙｐｈｙｌｌｏｓｉｄｅⅢ和Ⅳ,根据化学降解和光谱分析,它们的化学结构分别为２７－羟基－偏诺皂皂甙元－３－Ｏ［ａ－Ｌ－鼠李吡喃糖基（１→２）］［ａ－Ｌ－鼠李吡喃糖基（１→４－ａ－Ｌ鼠李吡喃糖基（１→４）］－β－Ｄ－葡萄吡喃糖甙,２３β,２７－二羟基－偏皂甙元－３－Ｏ－［ａ－鼠李吡喃糖（１→２）］     

环六亚甲基双乙酰胺对人胃癌MGc80-3细胞的诱导分化及PKA-RⅡ与PKC-α亚型在细胞内分布的变化

用HMBA作为诱导分化剂.研究了HMBA对人胃癌MGc80-3细胞的诱导分化效应,并采用免疫荧光技术观察了PKA-RⅡ与PKC-α亚型在细胞内分布的变化.细胞经5mmol/L HMBA处理后,细胞形态产生明显变化.细长突起明显增加,生长速度减慢,倍增时间延长.24小时,48小时,72小时的生长抑制率分别为20%.40.6%.54.8%.细胞在软琼脂上生长不成集落.细胞周期时相的分布发生变化、G_0+G_1期比对照组增加18.4%.而s期细胞比对照组减少14.8%.细胞内cAMP、DG水平也发生了显著变化.HMBA处理24小时后.细胞内cAMP水平上升62%.DG水平下降64.7.处理48小时后.cAMP水平上升76.2%.而DG水平下降的69.8%.以上结果充分表明了HMBA对人胃癌MGc80-3细胞的诱导分化作用.实验中还发现细胞经HMBA处理后.PKC-α分布于胞质,而PKA-RⅡ向胞核移位.提示HMBA对细胞的诱导分化作用与信号传递通路密切相关.     

环六亚甲基双乙酰胺对人胃癌MGc80-3细胞的诱导分化及PKA-RⅡ与PKC-α亚型在细胞内分布的变化

用HMBA作为诱导分化剂.研究了HMBA对人胃癌MGc80-3细胞的诱导分化效应,并采用免疫荧光技术观察了PKA-RⅡ与PKC-α亚型在细胞内分布的变化.细胞经5mmol/L HMBA处理后,细胞形态产生明显变化.细长突起明显增加,生长速度减慢,倍增时间延长.24小时,48小时,72小时的生长抑制率分别为20%.40.6%.54.8%.细胞在软琼脂上生长不成集落.细胞周期时相的分布发生变化、G_0+G_1期比对照组增加18.4%.而s期细胞比对照组减少14.8%.细胞内cAMP、DG水平也发生了显著变化.HMBA处理24小时后.细胞内cAMP水平上升62%.DG水平下降64.7.处理48小时后.cAMP水平上升76.2%.而DG水平下降的69.8%.以上结果充分表明了HMBA对人胃癌MGc80-3细胞的诱导分化作用.实验中还发现细胞经HMBA处理后.PKC-α分布于胞质,而PKA-RⅡ向胞核移位.提示HMBA对细胞的诱导分化作用与信号传递通路密切相关.     

两种第二信使系统在人胃癌MGc80-3细胞增殖分化调节中的相互关系

两种第二信使系统的正负调控作用的假说与细胞增殖失控的癌变机理之间关系,日益引起人们的注意。为此本工作利用HMBA 诱导分化剂和信使通路的阻断剂研究了两种第二信使系统(DG-PKC,cAMP-PKA)在人胃癌MGc80-3细胞生长分化调控过程中的相互关系。人胃癌MGc 80-3细胞在诱导分化剂处理24 h 后,其DG 水平与PKC 活性分别下降了64.7%和28.7%,而cAMP 及其结合蛋白的含量分别上升了62%和32.6%(48 h 后结果更为显著)。PKA-RⅡ表达增强,并从胞质移向核内分布。当用PKC 抑制剂H_7取代HMBA,阻断PKC 通路,24 h 后,DG 水平及PKC 活性均下降,而cAMP 含量上升了1.04倍。反之在HMBA 诱导分化的同时加入PKA 抑制剂使其cAMP 通路受到阻断后,cAMP 及其结合蛋白含量下降。而DG 含量与PKC 活性均上升到与对照组水平相似。PKA-RⅡ又仅仅在胞质中出现。以上实验充分显示了cAMP-PKA 与DG-PKC 两种信使系统在细胞增殖分化中的正负调控作用占有重要地位。     

In vitro and in vivo studies on antitumor effects of gossypol on human stomach adenocarcinoma (AGS) cell line and MNNG induced experimental gastric cancer

The present study has evaluated the chemopreventive effects of gossypol on N-methyl-N′-nitro-N-nitrosoguanidine (MNNG)-induced gastric carcinogenesis and on human gastric adenocarcinoma (AGS) cell line. Gossypol, C₃₀H₃₀O₈, is a polyphenolic compound that has anti proliferative effect and induces apoptosis in various cancer cells. The aim of this work was to delineate in vivo and in vitro anti-initiating mechanisms of orally administered gossypol in target (stomach) tissues and in human gastric adenocarcinoma (AGS) cell line. In vitro results prove that gossypol has potent cytotoxic effect and inhibit the proliferation of adenocarcinoma (AGS) cell line. In vivo results prove gossypol to be successful in prolonging the survival of MNNG induced cancer bearing animals and in delaying the onset of tumor in animals administrated with gossypol and MNNG simultaneously. Examination of the target (stomach) tissues in sacrificed experimental animals shows that administration of gossypol significantly reduces the level of tumor marker enzyme (carcino embryonic antigen) and pepsin. The level of Nucleic acid contents (DNA and RNA) significantly reduces, and the membrane damage of glycoprotein subsides, in the target tissues of cancer bearing animals, with the administration of gossypol. These data suggest that gossypol may create a beneficial effect in patients with gastric cancer.     

Arylpropionic acid-derived NSAIDs: New insights on derivatization,anticancer activity and potential mechanism of action

NSAIDs displayed chemopreventive and anticancer effects against several types of cancers. Moreover, combination of NSAIDs with anticancer agents resulted in enhanced anticancer activity. These findings have attracted much attention of researchers working in this field. The 2-arylpropionic acid-derived NSAIDs represent one of the most widely used anti-inflammatory agents. Additionally, they displayed antiproliferative activities against different types of cancer cells. Large volume of research was performed to identify molecular targets responsible for this activity. However, the exact mechanism underlying the anticancer activity of profens is still unclear. In this review article, the anticancer potential, structure activity relationship and synthesis of selected profen derivatives were summarized. This review is focused also on non-COX targets which can mediate the anticancer activity of this derivatives. The data in this review highlighted profens as promising lead compounds in future research to develop potent and safe anticancer agents.