Chartspiroton, a Tetracyclic Spiro-naphthoquinone Derivative from a Medicinal Plant Endophytic Streptomyces

• DOI: 10.1021/acs.orglett.0c00696
• Publication Date: 2020-03-18T19:45:03Z
• Authors: Huimin Zhao; Aiping Yang; Jian Liu; Sheng Bao; Ren Peng; Yang Hu; Tianjie Yuan; Shurong Hou; Tian Xie; Qichun Zhang; Xiabin Chen; Xiachang Wang; Lihong Hu
• Keywords: 0301 basic medicine; Plants, Medicinal; Molecular Structure; Spectrum Analysis; 15. Life on land; Crystallography, X-Ray; Streptomyces; Biosynthetic Pathways; 3. Good health; Lactones; 03 medical and health sciences; Polyketides; Naphthoquinones

A novel 6/6/5/6 tetracyclic polyketide named chartspiroton (1) was isolated from a medicinal plant endophytic Streptomyces in Dendrobium officinale. The complete structure assignment with absolute stereochemistry was elucidated through spectroscopic data, computational calculations, and single-crystal X-ray diffraction. Chartspiroton features an unprecedented naphthoquinone derivative spiro-fused with a benzofuran lactone moiety. A plausible polyketide biosynthetic pathway for 1 suggested intriguing oxidative rearrangement steps to form the five-membered lactone ring.