11-Methoxyprostaglandin I2 79743-30-9 O-11-Methylprostaglandin I2 ether Pgi2 11-methyl ether Prosta-5,13-dien-1-oic acid, 6,9-epoxy-15-hydroxy-11-methoxy-, (5Z,9alpha,11alpha,13E,15S)- Prostaglandin I2 11-methyl ether