Sixteen D- and L-3-hydroxyacyl-L-leucine hydrazides related to viscosin have been synthesized. Condensation of DL-3-hydroxy fatty acids with L-leucine methyl ester by the azide method or the active ester method gave DL-3-hydroxyacyl-L-leucine methyl esters, which were then converted to their hydrazides. Each of the racemic hydrazides could readily be resolved into the respective optically active diastereoisomers by means of fractional crystallization using alcohols. All of the D- and L-3-hydroxyacyl-L-leucine hydrazides prepared showed antimicrobial activity against four kinds of microorganisms only comparable to or less than that of the saturated straight chain fatty acids of corresponding carbon numbers.
已经合成了16种与
粘菌素相关的D-和L-3-羟基酰基-
L-亮氨酸酰
肼。通过
叠氮化法或活性酯法将DL-3-羟基
脂肪酸与
L-亮氨酸甲酯缩合,得到DL-3-羟基酰基-
L-亮氨酸甲酯,然后将其转化为酰
肼。通过
醇类分馏结晶法,每种外消旋酰
肼都可以很容易地转化为各自的光学活性非对映异构体。制备的所有D-和L-3-羟基酰基-
L-亮氨酸酰
肼对四种微
生物的抗菌活性仅与相应碳数的饱和直链
脂肪酸相当或更低。