Study on Surfactin, a Cyclic Depsipeptide. II. Synthesis of Surfactin B2 Produced by Bacillus natto KMD 2311.
作者:Sotoo NAGAI、Keiko OKIMURA、Naohito KAIZAWA、Kazuhiro OHKI、Shoichi KANATOMO
DOI:10.1248/cpb.44.5
日期:——
The total synthesis of surfactin B2, a cyclic depsipeptide isolated from Bacillus natto KMD 2311, was achieved to elucidate the absolute configuration of its fatty acid moiety. This is the first chemical confirmation of the absolute configuration of a surfactin homolog. Two possible diastereoisomers of surfactin B2, cyclo[D- and L-3-(Glu-Leu-D-Leu-Val-Asp-D-Leu-Leu-O)-n-tetradecanoyl] (1a and b), were synthesized by a solution method using mainly active ester and azide fragment condensation methods. Cyclization reaction of the partially protected linear depsipeptide containing the C-terminal N-succinimidyl active ester in pyridine by the high dilution method at room temperature for 3d gave the desired cyclic depsipeptide in a high yield of about 70%. The synthetic product 1a, containing the D-isomer of 3-hydroxytetradecanoic acid as a fatty acid moiety, was identical with natural surfactin B2.
通过全合成从纳豆芽孢杆菌(Bacillus natto KMD 2311)中分离出的环状去肽表面活性素 B2,阐明了其脂肪酸分子的绝对构型。这是首次用化学方法确认表面活性素同源物的绝对构型。主要采用活性酯和叠氮片段缩合的溶液法合成了表面活性剂 B2 的两种可能的非对映异构体--环[D-和 L-3-(Glu-Leu-D-Leu-Val-Asp-D-Leu-Leu-O)-n-十四碳酰基](1a 和 b)。将含有 C 端 N-琥珀酰亚胺基活性酯的部分保护线性去肽在吡啶中用高稀释法在室温下环化反应 3d 后,得到了所需的环状去肽,收率高达 70%。合成产物 1a 含有作为脂肪酸分子的 3-hydroxytetradecanoic acid 的 D-异构体,与天然表面活性剂 B2 相同。