13-hydroxylation of tetrahydroberberine in cell suspension cultures of some Corydalis species

Article abstract of DOI:10.1016/0031-9422(95)00813-6

Liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry was applied to biotransformation experiments in cultured cells of Corydalis ophiocarpa as well as C. ochotensis var. raddeana. Hydroxylation at C-13 of tetrahydroberberine was shown to take place in cell cultures as well as in C. ophiocarpa plants. N-Methylation of tetrahydroberberine occurred to form the α-N-metho salt incorporating the B/C-cis-quinolizidine system. Introduction of the C-13 methyl with berberine as substrate was confirmed to provide 13-methylberberine. In addition, the reversible oxidation-reduction of the C ring of protoberberines was demonstrated. Copyright