Crystal Structure and Anticancer Properties of Cinobufagin 3-Hemisuberate Methyl Ester

The title compound cinobufagin 3-hemisuberate methyl ester(1) was isolated from the venom of Bufo bufo gargarizans CANTOR. The crystal structure of 1, C35H48O9, was determined by single-crystal X-ray diffraction analysis. It belongs to orthorhombic, space group P212121 with a = 8.9338(3), b = 16.2970(4), c = 22.4019(6) , V = 3261.59(16) 3, Mr = 612.73, Z = 4, Dc = 1.248 g/cm3, μ = 0.725 mm-1, F(000) = 1320, S = 1.040, the final R = 0.0374 and wR = 0.0412 for 4458 unique reflections, of which 4088 were observed(I 2σ(I)). In the solid state, short intermolecular C-H...O interactions involving a methine and the ester carbonyl group in cinobufagin moiety and a methyl in the suberate moiety linked adjacent molecules into a three-dimensional network. Detailed analysis of the 1H-NMR data showed that X-ray structure of 1 would be expected to closely resemble the solution conformation in chloroform. Compound 1 was inactive for the inhibition of PC3 and HepG2 cancer cells, but the parent compound cinobufagin showed potent inhibition with IC50 values of 0.145 and 5.48 μM, respectively, indicating that esterification at C(3) decreased the cytotoxic effect of 1.     

高效液相色谱-静电场轨道阱质谱鉴定大鼠血浆中蟾蜍二烯内酯及其代谢物

建立了高效液相色谱-质谱鉴定大鼠口服蟾酥总内酯提取物后血浆中蟾蜍二烯内酯类化合物及其主要代谢物的分析方法.大鼠单剂量灌胃(50 mg/kg)蟾酥总内酯提取物后收集血浆样品,乙腈沉淀蛋白,浓缩定容,采用HPLC-MS分析.利用色谱保留时间、高分辨质谱提供的精确分子量和碎片离子精确质量的信息,鉴定了24种蟾蜍二烯内酯类化合...     

Synthesis,Crystal Structure and Na~+/K~+-ATPase Inhibitory Activity of △~(14,15)-anhydro-24-thiocarbonylbufalin

The title compound △14,15-anhydro-24-thiocarbonylbufalin(1) was prepared by the reaction of natural product bufalin with Lawesson reagent. The crystal structure of 1, C24H30O2S·C24H30O2S, was determined by single-crystal X-ray diffraction analysis. It belongs to monoclinic, space group C2, with a = 30.9845(2), b = 6.8036(3), c = 22.5791(15) , V = 4241.7(4) 3, Mr = 384.21, Z = 4, Dc = 1.204 g/cm3, μ = 1.463 mm-1, F(000) = 1664, S = 1.064, R = 0.0487 and wR = 0.0645 for 4683 unique reflections, of which 3757 were observed(I 2■(I)). The asymmetric unit contains two independent molecules(I and Ⅱ), which are closely similar to each other except for the orientation of the lactone ring. Both conformations of I and Ⅱ are in good agreement with the solution structure in methanol as indicated by 1H-NMR analysis. Due to the presence of heavy atom sulfur in the molecules, the final refinement resulted in a small Flack parameter 0.02(3), permitting the assignments of the absolute configuration. In the solid state, intermolecular hydrogen bonds involving thiocarbonyl group in the lactone moiety and the hydroxyl groups in the steroid moiety ester linked adjacent molecules into a three-dimensional network. Compound 1 showed weak inhibition on Na+/K+-ATPase in contrast to the strong inhibitory activity of the parent compound bufalin, suggesting that the carbonyl group in lactone moiety and the hydroxyl group at C-14 play important roles for the inhibition of Na+/K+-ATPase.