Schinnerl, Johann; Brem, Brigitte; But, Paul Pui-Hay; Vajrodaya, Srunya; Hofer, Otmar; Greger, Harald.
"Pyrrolo- and pyridoazepine alkaloids as chemical markers in Stemona species."
Phytochemistry (Elsevier) (2007), 68(10), 1417-1427
Abstract:
"Broad-based phytochem. investigations on 31 Stemona species and geog. provenances led to an overview concerning characteristic accumulation trends and the distribution of different Stemona alkaloids. Two major metabolic differences suggested a taxonomic segregation of the complex Stemona tuberosa group from the other species, and was supported by morphol. characters. Whereas most of the Stemona species were characterized by protostemonine type alkaloids, the S. tuberosa group clearly deviated by accumulation trends towards tuberostemonine or croomine derived alkaloids belonging to two different skeletal types. Also of chemotaxonomic relevance was the structural divergence of protostemonine type alkaloids into pyrrolo- or pyridoazepine derivs. represented by stemofoline or oxystemokerrine, resp., as major constituents. Their common occurrence in different provenances of S. curtisii, also deviating from the other species by various chromosome nos., deserves special taxonomic attention. Species specific chem. markers were given by the unique accumulation of didehydrostemofoline (=asparagamine A) in S. collinsae and stemokerrine in S. kerrii. In contrast to previous reports, no bisdehydro derivs. with an arom. pyrrole ring were detected supporting the hypothesis that these alkaloids are artifacts. A new stereoisomer of tuberostemonine was isolated and identified by spectroscopic methods."
