Bamrung Tantisewie

The protoberberine alkaloids of Stephania suberosa

Abstract Six new protoberberines were found in Stephama suberosa root extracts: (−)-tetrahydrostephabine, (−)-stephabinamine, stephabine, 8-oxypseudopalmatine, (−)- trans -xylopinine N -oxide and (−)- cis -xylopinine N -oxide. Ten known alkaloids were also detected: (−)-tetrahydropalmatine, (−)-tetrahydropalmatrubine, (−)-stepholidine, (−)-kikemanine, (−)-capaurimine, (−)-coreximine, (−)-corytenchine, (−)-discretine, pseudopalmatine and (−)-xylopinine.

A new subgroup of bisbenzylisoquinoline alkaloids: (+)-cycleatjehenine and (+)-cycleatjehine

The leaves of Cyclea atjehensis Forman (Menispermaceae) of Thai origin have yielded the bisbenzylisoquinolines (+)-cycleatjehenine(1a) and (+)-cycleatjehine(6) . These alkaloids incorporate the unusual methyleneoxy bridge, and belong to a new bisbenzylisoquinoline subgroup.

4,5,6,6a-Tetradehydro-N-methyl-7-oxoaporphinium salts

Stephania venosa Spreng. (Menispermaceae) has yielded the first two 4,5,6,6a-tetradehydro-N-methyl-7-oxoaporphinium salts known, namely uthongine (4) and thailandine (5), which are partially decomposed by chromatography on silica gel to 7-oxocrebanine (6) and 7-oxostephanine (7), respectively.