A study of the calcium complex of a glucosylceramide, soya-cerebroside II

Abstract

In order to study calcium ion complex of soya-cerebroside II (1), an ionophoretic glucosylceramide isolated from soybean, C8-cerebroside (3) and 3,3″,6″-trideoxy-C8-cerebroside (4) are designed and synthesized. On the basis of extensive 1H-NMR studies in the presence of Ca 2+ and a continuous variation method via 1H-NMR, soyacerebroside II is suggested to form a calcium complex with 1/Ca2+ ratio of 1 : 1. Soya-cerebroside II serves as a tridentate chelating ligand for Ca2+; the amide carbonyl, C2′-hydroxy, and C2″-hydroxy oxygens are responsible for the Ca2+ binding. Soya-cerebroside II is structurally analogous to a neural glucosylceramide. Thus, the accumulated neural glucosylceramide inside of endoplasmic reticulum (ER) membrane may serve as an endogenous Ca2+-binding and -transport molecule (ionophore) that result in mobilization of Ca2+ from intracellular calcium stores. © 2007 Pharmaceutical Society of Japan.