Purines. XXXIII. Syntheses and cytokinin activities of both enantiomers of 1'-methylzeatin and their 9-.BETA.-D-ribofuranosides.
作者:Tozo FUJII、Taisuke ITAYA、Satoshi MATSUBARA
DOI:10.1248/cpb.37.1758
日期:——
The structures and absolute configurations of the cytokinins 1'-methylzeatin and its 9-riboside, both secreted by Pseudomonas syringae pv savastanoi, have been established as [R-(E)]-2-methyl-4-(9H-purin-6-ylamino)-2-penten-1-ol[(1'R)-2] and [R-(E)]-N-(4-hydroxy-1, 3-dimethyl-2-butenyl)adenosine [(1''R)-4], respectively, as a result of the chiral syntheses of (1'R)- and (1'S)-1'-methylzeatins [(1'R)-2 and (1'S)-2] and of their 9-β-D-ribofuranosides [(1''R)-4 and (1''S)-4] from D- and L-alanines. These zeatin derivatives were tested for cytokinin activity in the tobacco callus and the lettuce seed germination bioassays. The "natural" enantiomer (1'R)-2 was found to be as active as zeatin (1) itself and more active than its 9-riboside [(1''R)-4]. The "unnatural" enantiomer (1'S)-2 and its 9-riboside [(1''S)-4] were less active than the corresponding natural cytokinins, (1'R)-2 and (1''R)-4, respectively.
由 Pseudomonas syringae pv savastanoi 分泌的细胞分裂素 1'-methylzeatin 及其 9-riboside 的结构和绝对构型已被确定,分别为 [R-(E)]-2-甲基-4-(9H-嘌呤-6-基氨基)-2-戊烯-1-醇[(1'R)-2]和 [R-(E)]-N-(4-羟基-1、(1'R)-和(1'S)-1'-甲基玉米素[(1'R)-2 和 (1'S)-2]及其 9-β-D-ribofuranosides [(1'R)-4和 (1'S)-4]的手性合成。这些玉米素衍生物在烟草胼胝体和莴苣种子萌发生物测定中进行了细胞分裂素活性测试。结果发现,"天然 "对映体(1'R)-2 的活性与玉米素(1)本身相同,而且比其 9-核苷[(1''R)-4]的活性更高。非天然 "对映体(1'S)-2 及其 9-核苷[(1''S)-4]的活性分别低于相应的天然细胞分裂素(1'R)-2 和 (1''R)-4)。