XPK xpk [(1~{R})-1-[(3~{S},5~{S},8~{R},9~{S},10~{S},13~{S},17~{R})-3-methanoyloxy-10,13-dimethyl-1,2,3,4,5,6,7,8,9,11,12,13,14,15,16,17-hexadecahydrocyclopenta[a]phenanthren-17-yl]ethyl]-methylidyne-azanium XPK