Mariko Kitajima

Alkaloids from Rauwolfia serpentina cell cultures treated with ajmaline

Abstract A group of new alkaloids, the raumaclines, and some related alkaloids were isolated from Rauwolfia serpentina cell suspensions fed with high levels of ajmaline; their structures were determined and syntheses developed providing an essential prerequisite to the further study of their biosynthesis at the enzymatic level.

Biomimetic synthesis of koumine by the palladium-catalyzed intramolecular coupling reaction of 18-hydroxytaberpsychine (18-hydroxyanhydrovobasinediol)

A principal Gelsemium alkaloid, koumine (1) was synthesized from 18-hydroxygardnutine (3) via the demethoxylation from the indole ring and the palladium-catalyzed cyclization between C 7 and C 20 of the hypothetical biogenetic intermediate, 18-hydroxytaberpsychine (2)

Synthesis of Na-methoxyindole and Na-methoxy-oxindole alkaloids having yohimbine skeleton

Indoloquinolizidine (1) and yohimbine (7) were converted to the corresponding N a -methoxyindoles and N a -methoxyoxindoles by the oxidation of the dihydroindole derivatives with H 2 O 2 and sodium tungstate