Akio Fukuzawa

Laurepinnacin and isolaurepinnacin, new acetylenic cyclic ethers from the marine red alga Laurencia pinnata Yamada

The Structure elucidation of the title compounds, two new insecticidal components of the marine red alga Laurencia pinnata Yamada, is described.

CONVERSION OF PRELAUREATIN INTO LAURALLENE, A BROMO-ALLENE COMPOUND, BY ENZYMATIC AND CHEMICAL BROMO-ETHERIFICATION REACTIONS

Abstract Studies on biomimetic conversion of prelaureatin into laurallene were reported. This unique bromo-allene compound has been assumed to be biogenetically synthesized by bromo-cationic reaction of prelaureatin, an eight-membered ether, containing an enyne unit. The electrophilic bromination afforded laurallene chemically and enzymatically.

Synthesis of (±)-prepinnaterpene, a bromoditerpene from the red alga Laurencia Pinnata Yamada

Abstract A total synthesis of (±)-prepinnaterpene, a brominated diterpene with a unique skeleton, and (±)-oppositol, a related sesquiterpene, is described.

Ecdysone-like metabolites, 14α-hydroxypinnasterols, from the red alga Laurencia pinnata

Abstract Four steroids with moulting hormone activity were isolated from Laurencia pinnata . These steroids are related structurally to β-ecdysone.

Laurallene, new bromoallene from the marine red alga Laurencia nipponica Yamada☆

Abstract Laurallene ( 1 ), a new brominated cyclic ether having a terminal allene moiety, has been isolated as a main constituent from the marine red alga Laurencia nipponica Yamada (Rhodomelaceae, Rhodophyta) and its structure was determined by its physical and chemical properties.

Acetylpinnasterol and pinnasterol, ecdysone-like metabolites, from the marine red alga yamada

Abstract The structures of two sterols, isolated from the title alga and designated as acetylpinnasterol and pinnasterol, were determined on the basis of the X-ray crystallography. These metabolites are the first marine phytosterols with ecdysone-like structures and biological activity as moulting hormones.

Glycinoeclepin A, a natural hatching stimulus for the soybean cyst nematode

A large-scale of isolation of glycinoeclepin A, a natural hatching stimulus for the soybean cyst nematode, and its structure elucidation by spectroscopic and X-ray methods are described.

Structure elucidation of laureoxanyne, a new nonisoprenoid C15 enyne, using lactoperoxidase

The enzymatic structure elucidation of a minor bicyclic nonisoprenoid C15 enyne, laureoxanyne, isolated from the red alga Laurencia nipponica, is described.

Laureepoxide, new bromo ether from the marine red alga Laurencia nipponica Yamada☆

Abstract An interesting bromine containing compound, laureepoxide ( 1 ), has been isolated from L . nipponica Yamada (Rhodomelaceae, Rhodophyta) and its structure has been determined by the chemical degradations and spectral properties.

Enzymatic Single-step Formation of Laureatin and Its Key Intermediate, Prelaureatin, from (3Z, 6S, 7S)-Laurediol

A bicyclic natural bromo ether, laureatin (7), and its monocyclic key intermediate, prelaureatin (6), have enzymatically been transformed from their original precursor, (3Z, 6S, 7S)-laurediol in single-step by lactoperoxidase.