1a,5,9-Trimethyl-13-methylene-12-oxo-1a,2,3,6,7,8,9,10,10a,12,13,13a,14,14a-tetradecahydrooxireno[2',3':4,5]cyclotetradeca[1,2-b]furan-10-yl acetate AIDS-136283 AIDS136283 EPA Eupalmerin acetate NSC637469