New dimeric morphine from opium poppy (Papaver somuniferum) and its physiological function.

Together with bismorphine A (1), a new compound bismorphine B (2) was identified in the wounded capsules of Papaver somniferum. On the basis of analyses of the various spectral data, bismorphine B (2) was determined as a novel morphinan alkaloid, in which two morphine units are coupled through a biphenyl ether bond. When the physiological function of bismorphine B (2) in opium poppy was investigated, it was evident that this alkaloid more effectively cross-links cell wall polysaccharide pectins than bismorphine A (1) and that such cross-linking reaction leads to resistance against hydrolysis by pectinase.