2-[29-(butan-2-yl)-21-(3,4-dihydroxybutan-2-yl)-2,14-dihydroxy-13-iodo-11-oxido-5,8,20,23,24,27,30,33-octaoxo-1,2,3,5,6,7,8,9,10,12,17,18,19,20,21,22,23,23a-octadecahydro-9,18-(epiminoethanoiminoethanoiminoethanoiminomethano)pyrrolo[1',2':8,9][1,5,8,11,14