5,7-Dihydroxy-2-(4-hydroxyphenyl)-4-oxo-4H-chromen-3-yl 2,6-bis-O-(6-deoxyhexopyranosyl)hexopyranoside AIDS-137338 AIDS137338 Kaempferol 3-O-(2,6-di-O-.alpha.-L-rhamnopyranosyl)-.beta.- D-galactopyranoside NSC641258