Kazusei Komatsu

Speradine A, a new pentacyclic oxindole alkaloid from a marine-derived fungus Aspergillus tamarii

A new pentacyclic oxindole alkaloid, speradine A (1), was isolated from the cultured broth of a fungus Aspergillus tamarii, which was separated from driftwood at a seashore in Okinawa. The structure and relative stereochemistry were determined by spectroscopic data and a single crystal X-ray diffraction analysis.

Seragakinone A, a new pentacyclic metabolite from a marine-derived fungus

Abstract A new anthracycline-derived pentacyclic metabolite, seragakinone A (1), was isolated from the mycelium of an unidentified fungus, which was separated from the Okinawan marine rhodophyta Ceralodictyon spongiosum, and the structure was elucidated by spectroscopic data.

Revised Stereochemistry and Biosynthesis of Seragakinone A

Abstract The relative stereochemistry of seragakinone A (1), an anthracycline-derived pentacyclic fungal metabolite, was revised by X-ray analysis. The tetracyclic skeleton (C-1–C-14) and the C5 moiety (C-1′–C-5′) of 1 were shown to be biosynthesized via decaketide and mevalonate pathway, respectively, on the basis of incorporation experiments.