preferred_name: [(3'R,4S,5'R,6S,6'S,8R,10E,13S,14E,16E,20R,21R,24S)-6'-[(E)-but-2-en-2-yl]-3',21,24-trihydroxy-5',11,13,22-tetramethyl-12-(2-methylpropanoyloxy)-2-oxospiro[3,7,19-trioxatetracyclo[15.6.1.14,8.020,24]pentacosa-10,14,16,22-tetraene-6,2'-oxane]-4'-yl] 2-methylpropanoate