The synthesis and biological evaluation of sixteen-membered macrolides possessing a 4-O-alkyl-α-L-cladinosyl moiety as a neutral sugar are described. These potent novel derivatives have been efficiently synthesized avoiding glycosylations. Two hydroxyl groups in mycarose of the tri-(tert-butyldimethylsilyl) ether intermediate were successively alkylated. Sequential deprotections of silyl groups afforded 4-O-alkyl-L-cladinose analogues and 3, 4-di-O-alkyl-L-mycarose analogues of leucomycin V. Some 4-O-alkyl-L-cladinose analogues exhibited potent antibacterial activities. The most active derivative, 3"-O-methyl-4"-O-(3-methylbutyl)leucomycin V, showed improved metabolic stability in rat plasma in vitro and extremely high concentrations in serum after oral administrations in mice and in hamsters.
本文描述了具有 4-O- 烷基-α-L-克拉地诺糖基作为中性糖的十六元大环内酯的合成和
生物学评价。这些有效的新型衍
生物是在避免糖基化的情况下高效合成的。三-(叔丁基二甲基
硅基)醚中间体中的两个羟基先后被烷基化。一些 4-O 烷基-L-
克拉霉素类似物具有很强的抗菌活性。活性最强的衍
生物 3"-O- 甲基-4"-O-(3-甲基丁基)
白霉素 V 在体外大鼠血浆中的代谢稳定性有所提高,在小鼠和仓鼠口服后血清中的浓度极高。