Bacogenin-A1: A novel dammarane triterpene sapogenin from Bacopa monniera

The constitution of bacogenin-A₁, obtained from the acid hydrolysate of bacoside-A, has been established as 3,18-dihydroxy-20 → 25-epoxy-22(or 23)-methyl-24-nor-dammar-22-en-16-one. The treatment of di-O-acetylbacogenin-A₁ with RuO₄ led to a diol instead of the usual dioxo product.     

Rearrangement of 23-oxospirostanes to the 22-oxo-23-spiroketal isomers promoted by Lewis acids--X-ray crystal structure of (23R,25S)-3beta-acetoxy-16beta,23:23,26-diepoxy-5beta-cholestan-22-one

Both 25R and 25S 23-oxospirostanes undergo rearrangement to the 22-oxo-23-spiroketal isomers promoted by Lewis acids. An X-ray crystal structure analysis of the rearranged product of 23-oxosarsasapogenin acetate confirmed the R configuration at the new spiro carbon atom.     

不同居群盾叶薯蓣生长、叶形态及皂苷元含量的研究

对引自湖北武当山、湖南南部和西北部的12个居群盾叶薯蓣的生长状况及叶形、叶色、叶长、叶宽、叶基、叶张角等12个形态指标进行了观测和比较分析,并测定了各居群的叶和块茎中的皂苷元含量。结果表明：1）在置信水平λ=8.0340时,11个居群可划分成2大类型：①长叶型：主要形态特征为叶片长度大于宽度,中裂片相对较长;②宽叶型：主要形态特征为叶片宽度大于长度,中裂片相对较短;2）不同居群盾叶薯蓣花序数、叶片总数、开花时间、花期长短、茎干重、叶干重等存在显著的差异;3）不同居群皂苷元含量差异也较显著,居群块茎中薯蓣皂苷元含量最高达3.98%（3号）、最低（7号）仅0.33%,而居群叶中约莫皂苷元含量最高达4.27%(4号）、最低（2号）为0.98%。     

Inhibitory effects of ginseng sapogenins on the proliferation of triple negative breast cancer MDA-MB-231 cells

Because of poor prognosis, clinical treatment of triple-negative (TN) breast cancer remains the most challenging factor in cancer treatment. Extensive research into alternative cancer therapies includes studying the naturopathic effects of the medicinal herb ginseng. This study investigates the anti-neoplastic properties of ginseng sapogenins and the derivatives: (1) (20(S)-protopanaxadiol (PPD), (2) 20(S)-protopanaxatriol), (3) (20(S)-dihydroprotopanaxadiol, and (4) 20(S)-dihydroprotopanaxatriol). These compounds were found to prevent the proliferation of MDA-MB-231 human breast cancer cells. PPD was the most potent inhibitor, exhibiting an IC₅₀ (5.87 μM) comparable to that of the chemotherapeutic drug taxol. Furthermore, PPD induced dose-dependent cleavage of caspase-8, caspase-3, and PARP in MDA-MB-231 cells. Thus, we propose that PPD acts as anti-cancer agent by stimulating caspase-dependent apoptosis in breast cancer cells.     

Regioselective cleavage of rings E and F in sarsasapogenin

Sapogenins from the 25R and 25S series show a marked difference on the E/F regioselectivity of the spiroketal cleavage with BF(3)/Ac(2)O. In contrast to the high yield of single E-ring cleavage products from diosgenin (3) and hecogenin (5), sapogenins of the 25R series (equatorial C-27 methyl), sarsasapogenin (1, 25S series, axial C-27 methyl) yields the corresponding acetyldihydropyran, (25S)-23-acetyl-22,26-epoxy-5beta-cholest-22-ene-3beta,16beta-diyl diacetate (8), two isomeric furostenes: (E)- and (Z)-(25S)-23-acetyl-5beta-furost-22-ene-3beta,26-diyl diacetate (9 and 10) and a third one bearing an additional acetyl group: (E)-(20S,25S)-20,23-diacetyl-5beta-furost-22-ene-3beta, 26-diyl diacetate (11). The structures of the compounds were unambiguously established using two dimensional NMR techniques. The lower E/F selectivity in the cleavage of 1 is attributed to steric hindrance resulting from the axial methyl in F ring on a beta elimination forming the dihydropyran double bond in the major product 8.     

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。     

Intestinal disaccharidases and some renal enzymes in streptozotocin-induced diabetic rats fed sapogenin extract from bitter yam (Dioscorea polygonoides)

In this study, the effects of bitter yam sapogenin extract or commercial diosgenin on intestinal disaccharidases and some renal enzymes in diabetic rats were investigated. Diabetic male Wistar rats were fed diets supplemented with 1% sapogenin extract or commercial diosgenin for 3 weeks. Plasma glucose, intestinal disaccharidases and the activities of transaminases, acid phosphatase, glucose-6-phosphatase, ATP citrate lyase, glucose-6-phosphate dehydrogenase and pyruvate kinase were assessed for the level of metabolic changes in the kidney of diabetic rats. Sapogenin extract or commercial diosgenin supplementation resulted in a significant decrease in lactase and maltase activities in all three regions of the intestine compared to the diabetic control group. However, the test diets significantly reduced intestinal sucrase activity in the proximal and mid regions. Test diets supplementation resulted in a significant decrease in the activities of the transaminases compared to the normal and diabetic control groups. The activity of glucose-6-phosphatase was significantly increased while the activities of ATP citrate lyase, pyruvate kinase and glucose-6-phosphate dehydrogenase were significantly reduced in the kidney of the diabetic control rats compared to the normal group. Test diets supplementation did not significantly alter glucose-6-phosphatase, ATP citrate lyase and pyruvate kinase activities compared to the diabetic control. However, there was a significant increase in glucose-6-phosphate dehydrogenase activity toward the normal group. In conclusion, the consumption of bitter yam sapogenin extract or commercial diosgenin demonstrated hypoglycemic properties, which are beneficial in diabetes by reducing intestinal disaccharidases activities; however, bitter yam sapogenin extract may adversely affect the integrity of kidney membrane.