Matern U, Oberer L, Falchetto R A, Erhard M, König W A, Herdman M, Weckesser J
Institut für Biologie II (Mikrobiologie), Albert-Ludwigs-Universität, Schänzlestrasse 1, D-79104 Freiburg i. Br., Germany.
Phytochemistry. 2001 Dec;58(7):1087-95. doi: 10.1016/s0031-9422(01)00400-9.
Two novel cyclic depsipeptides were isolated from axenic cultures of the terrestrial cyanobacterium Scytonema hofmanni PCC 7110 and designated scyptolin A and B. Amino acid analyses in context with mass and 1H/13C NMR spectroscopies revealed a composition typical for heterologous cyanopeptolins but containing the uncommon residue 3'-chloro-N-methyl-Tyr (cmTyr) and a unique sidechain. Scyptolin A and B both consist of the N-acylated peptide But(1)-Ala(2)-Thr(3)-Thr(4)-Leu(5)-Ahp(6) (3-amino-6-hydroxy-2-oxo-1-piperidine)-Thr(7)-cmTyr(8)-Val(9), which forms a 19-membered ring by esterification of the carboxyl of Val(9) with the hydroxyl of Thr(4). In scyptolin B, the hydroxyl of the Thr(3) residue is additionally esterified with N-butyroyl-Ala. Both scyptolin A and B exhibit selective inhibition of porcine pancreatic elastase in vitro with IC(50) values of 3.1 microg/ml.
从陆生蓝藻霍夫曼席藻（Scytonema hofmanni）PCC 7110的无菌培养物中分离出两种新型环缩肽，分别命名为scyptolin A和B。结合质谱和1H/13C NMR光谱进行的氨基酸分析显示，其组成具有异源蓝藻肽典型特征，但含有不常见的残基3'-氯-N-甲基-Tyr（cmTyr）和独特的侧链。Scyptolin A和B均由N-酰化肽But(1)-Ala(2)-Thr(3)-Thr(4)-Leu(5)-Ahp(6)（3-氨基-6-羟基-2-氧代-1-哌啶）-Thr(7)-cmTyr(8)-Val(9)组成，该肽通过Val(9)的羧基与Thr(4)的羟基酯化形成一个19元环。在scyptolin B中，Thr(3)残基的羟基还与N-丁酰-Ala酯化。Scyptolin A和B在体外均对猪胰弹性蛋白酶具有选择性抑制作用，IC(50)值为3.1微克/毫升。
