STUDIES ON THE CHEMICAL CONSTITUENTS OF ANNONA SQU AMOSA SEED

A new polyketide,squamostatin-B(Ⅰ),two known polyketides, annonin-Ⅳ(Ⅱ)and desacetyluvaricin(Ⅲ),and daucosterol(Ⅳ)have been isolated from Annona squamosa L.(Annonaceae).The structure and relative stereochemistry of I were elucidated on the basis of spectralanalvsis of I and its acetate(Ia) and mesitoate(Ib)。