Department of Chemistry and Biochemistry, and §Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California , San Diego, 9500 Gilman Drive MC-0358, La Jolla, California 92093-0358, United States.
J Org Chem. 2018 Feb 2;83(3):1278-1286. doi: 10.1021/acs.joc.7b02813. Epub 2018 Jan 23.
Six new cyclopenta[g]indoles were isolated from a West Australian sponge, Trikentrion flabelliforme Hentschel, 1912, and their structures elucidated by integrated spectroscopic analysis. The compounds are analogues of previously described trikentrins, herbindoles, and trikentramides from related Axinellid sponges. The assignment of absolute configuration of the new compounds was carried out largely by comparative analysis of specific rotation, calculated and measured ECD, and exploiting van't Hoff's principle of optical superposition. Five of the new compounds were chemically interconverted to establish their stereochemical relationships, leading to a simple chiroptical mnemonic for assignment of the this family of chiral indoles. The first biosynthetic hypothesis is advanced to explain the origin of the trikentrin-herbinole family and proposes a pyrrole-carboxylic thioester-initiated polyketide synthase mechanism.
从西澳大利亚海绵 Trikentrion flabelliforme Hentschel, 1912 中分离得到六个新的环戊[g]吲哚，并通过综合光谱分析阐明了它们的结构。这些化合物是先前描述的来自相关 Axinellid 海绵的 trikentrins、herbindoles 和 trikentramides 的类似物。新化合物的绝对构型的分配主要通过比较比旋光度、计算和测量的 ECD 以及利用 van't Hoff 的光学叠加原理来进行。五个新化合物通过化学转化相互转化以建立它们的立体化学关系，从而为这一系列手性吲哚的分配提供了一个简单的手性记忆。提出了第一个生物合成假设来解释 trikentrin-herbinole 家族的起源，并提出了一个吡咯羧酸硫酯起始的聚酮合酶机制。
