ARAGUSPONGINES B, C, D, E, F, G, H, AND J, NEW VASODILATIVE BIS-1-OXAQUINOLIZIDINE ALKALOIDS FROM AN OKINAWAN MARINE SPONGE, XESTOSPONGIA SP.

Abstract

Nine new vasodilative alkaloids, araguspongines A, B (1__∼), C(2__∼), D(3__∼), E(4__∼), F(5__∼), G(6__∼), H(7__∼), and J(8__∼), were isolated from an Okinawan marine sponge, Xestospongia sp. On the basis of chemical and physicochemical evidence, the absolute stereostructures of araguspongines B, D, E, F, G, H, and J were determined respectively as 1__∼, 3__∼, 4__∼, 5__∼, 6__∼, 7__∼, 8__∼, and the relative stereostructure of araguspongine C was determined as 2__∼having two 1-oxaquinolizidine moieties. Araguspongines B, D, and E each comprised a pair of the enantiomers (1a)___∼ and (2b)___∼, (3a)___∼ and (3b)___∼, and (4a)___∼ and &(4b)___∼, respectively.