Rhodopeptins, Novel Cyclic Tetrapeptides with Antifungal Activities from Rhodococcus sp. III. Synthetic Study of Rhodopeptins.
作者:HIROYUKI CHIBA、HITOSI AGEMATU、KAZUYA SAKAI、KAZUYUKI DOBASHI、TAKEO YOSMOKA
DOI:10.7164/antibiotics.52.710
日期:——
separated. Coupling of both diastereomers, L-Val-beta-amino acids with Gly-L-Lys gave linear tetrapeptides, and tetrapeptides were cyclized by diphenylphosphoryl azide (DPPA) method between C-terminus of beta-amino acid and N-terminus of Gly to give cyclic tetrapeptides. The deprotected cyclic tetrapeptides, LV9nA and LV9nB, both exhibited almost the same antifungal activity as the naturally obtained
环(-Gly-Lys-L-Val-(R)-3-氨基十二烷酰基-)的总合成;LV9nA及其非对映体环(-Gly-L-Lys-L-Val-(S)-3-氨基十二烷酰基-); 获得了LV9nB,其为rhodopeptin B5的β-氨基酸部分。通过将胺热加成到α,β-不饱和酯上,将β-氨基酸部分制成外消旋物。将外消旋β-氨基酸转化为它们的L-戊酰胺衍生物,并分离得到的非对映异构体。两种非对映异构体,L-Val-β-氨基酸与Gly-L-Lys偶联生成线性四肽,并通过二苯基磷酰叠氮化物(DPPA)方法将四肽环化在β-氨基酸的C端和Gly的N端之间。得到环状四肽。去保护的环状四肽LV9nA和LV9nB,两者均显示出与天然获得的杜鹃肽几乎相同的抗真菌活性。此外,比较两个同类物和视紫红素B5的1H NMR谱图表明,天然视紫红素B5中β-氨基酸部分的立体化学具有(R)-构型。