Aplysiasecosterol A: A 9,11‐Secosteroid with an Unprecedented Tricyclic γ‐Diketone Structure from the Sea Hare Aplysia kurodai |
| |
| Authors: | Atsushi Kawamura Prof. Dr. Masaki Kita Prof. Dr. Hideo Kigoshi |
| |
| Affiliation: | Graduate School of Pure and Applied Sciences, University of Tsukuba, 1‐1‐1 Tennodai, Tsukuba 305‐8571 (Japan) |
| |
| Abstract: | A new 9,11‐secosteroid having an unprecedented tricyclic γ‐diketone structure, aplysiasecosterol A ( 1 ), was isolated from the sea hare Aplysia kurodai. The structure was determined by one‐ and two‐dimensional NMR spectroscopic analysis, molecular modeling studies, a comparison of experimental and calculated ECD spectra, and a modified Mosher′s method. Aplysiasecosterol A ( 1 ) exhibited cytotoxicity against human myelocytic leukemia HL‐60 cells. A biosynthetic pathway for 1 from a known cholesterol was proposed and includes twice α‐ketol rearrangements and an intramolecular acetalization. |
| |
| Keywords: | biosynthesis circular dichroism natural products rearrangements structure elucidation |
|
|
