2H,16H-1,24-Etheno-6,10:11,15-dimethenopyrido[2',3':17,18]oxacycloeicosino[2,3,4-ij]isoquinoline-9,22-diol,3,5,16a,17,18,19-hexahydro-12,21,26-trimethoxy-17-methyl-, (R)-