(alphaR,2R,5S,6R)-alpha-ethyl-6-[(1S,2S,3S,5R)-5-[(2S,5S,7R,9S,10S,12R,15R)-2-[(2R,5R,6S)-5-ethyltetrahydro-5-hydroxy-6-methyl-2H-pyran-2-yl]-15-hydroxy-2,10,12-trimethyl-1,6,8-trioxydispiro[4.1.5.3]-pentadec-13-en-9-yl]-2-hydroxy-1,3-dimethyl-4-oxoheptyl]-tetrahydro-5-methyl-2H-pyran-2-acetic acid