Synthesis of [Gly-1]RA-VII, [Gly-2]RA-VII, and [Gly-4]RA-VII. Glycine-Containing Analogues of RA-VII, an Antitumor Bicyclic Hexapeptide from <i>Rubia</i> Plants
作者:Yukio Hitotsuyanagi、Tomoyo Hasuda、Takayuki Aihara、Hiroshi Ishikawa、Kentaro Yamaguchi、Hideji Itokawa、Koichi Takeya
DOI:10.1021/jo030293p
日期:2004.3.1
Three analogues of RA-VII (1), an antitumor bicyclic hexapeptide from Rubia plants, were synthesized. Three analogues, [Gly-1]RA-VII (4), [Gly-2]RA-VII (5), and [Gly-4]RA-VII (6), in which one of the three alanine residues in 1 was replaced by a glycine residue, were prepared by linking of the cycloisodityrosine unit, obtained by degradation of 1, to three different glycine-containing tetrapeptides
合成了RA-VII(1)的三种类似物,这是一种来自Rubia植物的抗肿瘤双环六肽。三个类似物,[甘氨酸- 1] RA-VII(4),[甘氨酸- 2] RA-VII(5),和[甘氨酸- 4] RA-VII(6),其中在这三个丙氨酸残基之一1通过将甘氨酸残基代替,通过将由1的降解获得的环异酪氨酸单元与三种不同的含甘氨酸的四肽连接,然后进行大环化,来制备α-氨基乙酸。在这三个类似物中,类似物4表现出最高的细胞毒性活性。NMR研究表明,溶液中类似物4的构象结构及其比率与天然肽1非常相似,表明Ala-2和Ala-4处的甲基对于产生生物活性构象应是必不可少的,而d -Ala-1处的甲基则不是必需的。