(R)-4-((3R,5S,6R,7S,8S,9S,10S,13R,14S,17R)-6-Ethyl-3-((R)-4-((3R,5S,6R,7S,8S,9S,10S,13R,14S,17R)-6-ethyl-3,7-dihydroxy-10,13-dimethyl-hexadecahydro-1H-cyclopenta[a]phenanthren-17-yl)pentanoyloxy)-7-hydroxy-10,13-dimethyl-hexadecahydro-1H-cyclopenta[a]phenanthren-17-yl)pentanoic acid