Cycloartanol Glycosides from the South African Folk Medicine Sutherlandia frutescens

Sutherlandia frutescens is known as a multipurpose medicinal plant in South African with a folk name of Cancer Bush. It has been used widely in Africa to treat gastrointestinal problems [1], cancers, inflammation, and AIDS [2]. It also showed promise for treatment of type II diabetes [3]. A previous phytochemical study shows it contains three chemicals: L-canavanine, pinitol and gamma-aminobutyric acid [4]. However, little is known about other chemical constituents of this plant. Our phytochemical investigation on Sutherlandia frutescens led to the isolation of four new triterpenoid glycosides, sutherlandioside A–D (1–4), whose structures were established by chemical and spectroscopic methods including X-ray crystallography. Compound 1 is a novel natural product possessing a 7,10-epoxy functionality in the secocycloartanol skeleton. Compounds 2–4 are also first examples of naturally occurring cycloartanols with a C-1 ketone functionality. Acknowledgements: The authors thank Dr. Avula Bharathi and Dr. Yan-Hong Wang for recording MS data, and Mr. Frank T. Wiggers for providing NMR data. This work is supported in part by “The International Center for Indigenous Phytotherapy Studies” funded by NCCAM, grant number 5 U19 AT 003264 and the USDA Agricultural Research Service Specific Cooperative Agreement No. 58-6408-2-0009. References: [1] Moshe D, et al. (1998) Biochem. Syst. Ecol. 26: 595–609. [2] Mills E, et al. (2005) Nutr. J. p.19–25. [3] Chadwick WA, et al. (2007) J. Ethnopharmacol. 109: 121–127. [4] Tai J, et al. (2004) J. Ethnopharmacol. 93: 9–19.