Aplysiasecosterol A: A 9,11-Secosteroid with an Unprecedented Tricyclic γ-Diketone Structure from the Sea Hare Aplysia kurodai

Atsushi Kawamura; Masaki Kita; Hideo Kigoshi

doi:10.1002/anie.201501749

Aplysiasecosterol A: A 9,11-Secosteroid with an Unprecedented Tricyclic γ-Diketone Structure from the Sea Hare Aplysia kurodai

Angew Chem Int Ed Engl. 2015 Jun 8;54(24):7073-6. doi: 10.1002/anie.201501749. Epub 2015 Apr 29.

Authors

Atsushi Kawamura¹, Masaki Kita², Hideo Kigoshi³

Affiliations

¹ Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8571 (Japan).
² Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8571 (Japan). mkita@chem.tsukuba.ac.jp.
³ Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8571 (Japan). kigoshi@chem.tsukuba.ac.jp.

PMID: 25925956
DOI: 10.1002/anie.201501749

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.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Aplysia / chemistry*
Aplysia / metabolism
Circular Dichroism
Ketones / chemistry
Magnetic Resonance Spectroscopy
Molecular Conformation
Quantum Theory
Secosteroids / chemistry*

Substances

Ketones
Secosteroids
aplysiasecosterol A