8-Keto-berberine (compound 29) is a non-naturally occurring 11, 12-oxygenated protoberberine derived from naturally occurring 9, 10-oxygenated protoberberine[1].
[1]. Miyoji Hanaoka, et al. Chemical transformation of protoberberines. VI. Ring D inversion of protoberberine alkaloids. Conversion of berberine into nonnaturally occurring 11,12-oxygenated protoberberines via spirobenzylisoquinolines. Chem.Pharm.Bull.1984;32(11):4431-4436.
















