Methyl (2S,4aS,4bR,10aR,10bR,12aS)-1,4,4a,4b,5,7,8,9,10,10a,10b,11,12,12a-tetradecahydro-6,10b-dihydroxy-2,4b,7,7,10a,12a-hexamethyl-12-methylene-1,4,5,8-tetraoxo-2H-phenanthro[1,2-c]pyran-2-carboxylate