alpha-THS (allo-THS), only the latter was active. These results suggest that the impurities present in 3 alpha, 5 beta-THS synthesized by reduction of the alpha, beta-unsaturated ketone of Substance S might be either or both the epi-/allo-epimers (3 beta, 5 beta-THS and 3 alpha, 5 alpha-THS, respectively), with only the latter contributing the positive angiostatic activity to the mixture. Of the two synthetically
来自不同来源的5 beta-四氢-赖希斯坦物质S(3 alpha,5 beta-
THS)在雏鸡绒膜尿囊膜测定系统中产生了可变的
生物测定活性。物理表征显示不纯的产物。通过两种不同的途径合成该化合物产生了活性和非活性的3α,5β-
THS。在其他两个差向异构体中,3个beta,5个beta-
THS(epi-
THS)和3个alpha,5个alpha-
THS(allo-
THS),只有后者是有活性的。这些结果表明,通过还原S物质的α,β-不饱和酮合成的3 alpha,5 beta-
THS中存在的杂质可能是表位/ allo表位异构体(3 beta,5 beta-
THS和分别为3 alpha,5 alpha-
THS),只有后者对混合物具有积极的血管抑制活性。在两种合成衍生的化合物中,