Nobuharu Shigematsu

Cytotoxic metabolites from a fungal adherent of a marine alga

Leptosins G, G1, G2 and H, belonging to a series of dimeric epipolythiodioxopiperazines, were isolated from the mycelium of a strain of Leptosphaeria sp. stuck on the marine alga Sargassum tortile. Their stereostructures were elucidated by chemical and spectral evidence.

Quercetin 3-(6″-caffeoylgalactoside) from Hydrocotyle sibthorpioides

Abstract In addition to quercetin, quercetin 3-galactoside and isorhamnetin, a new caffeoylgalactoside has been isolated from Hydrocotyle sibthorpioides and identified by chemical and spectral data as quercetin 3- O -β- d -(6″-caffeoylgalactoside).

Further phloroglucinol derivatives in the fruits of Mallotus japonicus

Abstract Two new rottlerin-like phloroglucinol derivatives were detected from the fruits of Mallotus japonicus and identified as 3-(3,3-dimethylallyl)-5-(3-acetyl-2,4-dihydroxy-5-methyl-6-methoxybenzyl)-phlorobutyrophenone and -phloroisobutyrophenone by spectral studies. 2,6-Dihydroxy-3-methyl-4-methoxyacetophenone was also isolated

Phloroglucinol derivatives from fruits of Mallotus japonicus

Abstract Two new rottlerin-like phloroglucinol derivatives were isolated from the fruits of Mallotus japonicus and identified by chemical and spectral data as 3-(3, 3-dimethylallyl)-5-(3-acetyl-2, 4-dihydroxy-5-methyl-6-methoxybenzyl)-phloracetophenone and 3-(3-methyl-2-hydroxybut-3-enyl)-5-(3-acetyl-2, 4-dihydroxy-5-methyl-6-methoxybenzyl)-phloroacetophenone.