五味子的环二肽及其合成

目的：研究五味子中的环肽成分。方法：用薄层色谱,硅胶及反向RP-18硅胶柱层析色谱和谱学方法。结果：分离到3个天然的环二肽及由3个环二肽组成的一个混合物并鉴定为环(亮-脯)(1),环(苯丙-脯)(2)和环(苯丙-亮)(3),环(苯丙-缬)(4),环(苯丙-异亮)(5),环(苯丙-苯丙)(6),另外,合成了14个环二肽类似物。结论：首次从五味子科植物北五味子中分离到环肽。环二肽2,6～8,14～20,经活性筛选表明,2,16及18有轻微的钙拮抗效应,19及20显示出增强高钾所致收缩效应。其它环二肽及它们的活性筛选工作正在进行中。

CYCLIC DIPEPTIDES FROM SCHIZANDRA CHINENSIS AND THEIR SYNTHESES

AIM: To investigate cyclopeptides from the fruits of S.chinensis. METHODS: Use thin layer chromatography, repeated silica geland RP-18 column chromatography together with spectra as well as synthetic methods. RESULTS: Three naturally occurring cyclic dipeptides and a mixture composed of three other new naturally occurring cyclic dipeptideswere obtained. Their structures were determined as cyclo-(leucyl-prolyl)(1), cyclo-(phenyl-alanyl-prolyl) (2), cyclo-(phenylalanyl-leucyl) (3), cyclo-(phenylalanyl-valyl) (4), cyclo-(phenylalanyl-isoleucyl) (5) and cyclo-(phenylalanyl-phenylalanyl) (6). In addition, fourteen analogous cyclic peptides (7～20) were synthesized. CONCLUSION: Cyclopeptides were isolated from S.chinensis (Schizandraceae) for the first time. The bioactivity of some cyclic dipeptides on the contraction of rabbit aortastrips with KCl (40 mmol.L^-1) depolarization was tested. Cyclic dipeptides 2, 6 and 18 showed slight calcium antagonism and 19, 20 can increase the contractile effect in high concentration of potassium. Studies on the bioactivities of other cyclic dipeptides are in progress.