(+/-)-(Z)-3-((2R,3S,4S)-4,5,9,10-Tetrahydroxy-2,3,8,8-tetramethyl-3,4,9,10-tetrahydro-2H, 8H-pyrano[2,3-f]chromen-6-yl)-hex-2-enoic acid methyl ester AIDS-163979 AIDS163979