Abstract
The pharmacology of phellodendrine, water soluble quaternary ammonium alkaloid, isolated from Phsllodendron amurense Rupr. by Tomita and Nakano (1) has been already reported by Shimamoto et al. (2). The' weak depressor effect of the drug was reported to derive from its ganglion blocking mechanism. Tomita and Nakano (3) obtained xylopinine (2, 3, 10, 11-tetramethoxy-5, 6-13, 13a-tetrahydro-8-dibenzo (a-g) quinolizine), a tertiary amine, by semisynthesis of phellodendrine. This compound coincides with O, O-demethyl-coreximine isolated by Manske (4), and also with O-methyldiscretine and xylopinine isolated by Schmutz (5) from xylopia discreta.
The chemical structure of xylopinine closely resembles to that of berberine which is also found in the Phellodendron amurense Rupr. in large amount (Fig. 1). Though the mechanism of the depressor response elicited by berberine remains still obscure (6-10), Mineshita et al. (11) showed that the relatively longer depressor action of tetrahydroberberine derived from the central mechanism. The chemical structure of xylopinine also resembles to those of benzoquinolizine derivatives, which deplete catecholamine and serotonin in the central nervous system and induce a sedation in a variety of animals (12-14). The mode of action of benzoquinolizine derivatives showed that the indole ring of reserpine was not indispensable for the manifestation of the characteristic effect of reserpine (15-25).
The pharmacological effects of xylopinine were studied in this experiment. Xylopinine showed a weak sedative and a long lasting depressor effects in a variety of animals.
