79 グアム産オゴノリ近縁種Polycavernosa tsudaiによる食中毒原因物質ポリカバノシド(Polycavernoside)の構造(ポスター発表の部)

抄録

Human intoxication resulting from ingestion of a red alga Polycavernoside tsudai occurred in Guam in April 1991. Our effort to identify the causative agents resulted in the isolation of two new toxins, polycavernoside A (A)(800μg) and B(400μg) from the alga P. tsudai. A: white amorphous, UV (MeCN) max λ 259, 270 and 280nm; IR (film) 1630, 1730 and 1738 cm^<-1>; HRFABMS[M+Na]^+ m/z 847.4529 (847.4455 calcd for [C_<43>H_<68>O_<15>Na]^+). Detailed analyses of ^1H-^1H COSY and 2D-HOHAHA, HMQC, HMBC and NOESY spectra allowed us to deduce the structure of A. Novelity of A is seen in a 13 membered lactone with a triene side chain, and O-α-2,3-di-O-methyl-Fucopyranosyl-(1-3)-O-β-2,4-di-O-methyl-xylopyranoside (Fig.3). The relative stereostructure was deduced mainly by NOE data. The stable comformations were calculated by Dreiding for the structural comfirmation.