3-[(3S,5R,8R,9S,10S,13S,14S,17S)-3,14,17-trihydroxy-10,13-dimethyl-2,3,4,5,6,7,8,9,11,12,15,16-dodecahydro-1H-cyclopenta[a]phenanthren-17-yl]-2H-furan-5-one