R27 r27 N'-[(3S,4R,5S,8R,9E,12S,14S,15R,16S,18R,19R,26aS)-5,19-dihydroxy-3-{(1E)-1-[(1R,3R,4R)-4-hydroxy-3-methoxycyclohexyl]prop-1-en-2-yl}-14,16-dimethoxy-4,10,12,18-tetramethyl-1,20,21-trioxo-8-(prop-2-en-1-yl)-1,3,4,5,6,8,11,12,13,14,15,16,17,18,19,20,21,23,24,25,26,26a-docosahydro-7H-15,19-epoxypyrido[2,1-c][1,4]oxazacyclotricosin-7-ylidene]acetohydrazide R27