Stereochemistry and biological activities of constituents from Cynanchum taiwanianum.
Stereochemistry and biological activities of constituents from Cynanchum taiwanianum.
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DOI：
10.1016/s0304-4165(97)00142-6
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发表时间：
1998-03
期刊：
影响因子：
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通讯作者：
C. Lin;P. Huang;J. J. Wang-J.;S. Day;H. C. Lin;J. P. Wang;Y. Ko;C. Teng
中科院分区：
文献类型：
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作者：
C. Lin;P. Huang;J. J. Wang-J.;S. Day;H. C. Lin;J. P. Wang;Y. Ko;C. Teng
从台湾白首乌中分离得到一个新的苯乙酮类化合物，白首乌二酮B-D（2-4），通过计算机模拟计算和NOESY光谱，确定了其立体化学结构。确定了白前二酮B-D（2-4）的绝对构型分别为7 R; 7″S、7S; 7″S和7 R; 7″R。白首乌二酮B（2）以浓度依赖方式强烈抑制甲酰甲硫氨酰亮氨酰苯丙氨酸（fMLP）刺激的大鼠中性粒细胞释放β-葡萄糖醛酸酶和溶菌酶，IC 50值分别为1.5±0.2和1.6±0.2μM。2，5-二羟基苯乙酮（6）对花生四烯酸诱导的兔血小板聚集有浓度依赖性抑制作用，IC_（50）约为4.8μM。在人柠檬酸盐富血小板血浆中，2，5-二羟基苯乙酮（6）抑制肾上腺素和ADP诱导的聚集的第二阶段，但不抑制第一阶段。这些结果表明，2，5-二羟基苯乙酮（6）的抗血小板作用是由于抑制血栓素A2的形成。
The stereochemistry of new acetophenones, cynandione B–D (2–4), isolated from Cynanchum taiwanianum, elucidated by computer modelling calculation and NOESY spectrum. It establishes the absolute configurations of cynandiones B–D (2–4) as 7R; 7″S, 7S; 7″S and 7R; 7″R, respectively. Cynandione B (2) strongly inhibited the release of β-glucuronidase and lysozyme in formyl–methionyl–leucyl–phenylalanine (fMLP)-stimulated rat neutrophils in a concentration-dependent manner with IC50values of 1.5±0.2 and 1.6±0.2μM, respectively. 2,5-Dihydroxyacetophenone (6) strongly inhibited the aggregation of washed rabbit platelets induced by arachidonic acid in a concentration-dependent manner with an IC50value of about 4.8μM. In human citrated platelet-rich plasma, 2,5-dihydroxyacetophenone (6) inhibited the secondary phase, but not the primary phase, of aggregation induced by adrenaline and ADP. These results suggest that the antiplatelet effect of 2,5-dihydroxyacetophenone (6) is due to inhibition of the formation of thromboxane A2.