Echinocystic Acid Bidesmoside Saponins from <i>Microglossa afzelii</i> O. Hoffm and Their Cytotoxic Activity against the CAL-27 Oral Squamous Carcinoma Cell Line
Billy Toussie Tchegnitegni,
Tehmina Ahmed,
Francis Tatong Ngouafong,
Viviane Flore Kamlo Kamso,
Rémy Bertrand Teponno,
Bruno Ndjakou Lenta,
Léon Azefack Tapondjou,
Arslan Ali,
Syed Ghulam Musharraf
Affiliations
Billy Toussie Tchegnitegni
Department of Chemistry, Faculty of Science, University of Dschang, Dschang P.O. Box 67, Cameroon
Tehmina Ahmed
Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
Francis Tatong Ngouafong
Department of Chemistry, Faculty of Science, University of Dschang, Dschang P.O. Box 67, Cameroon
Viviane Flore Kamlo Kamso
Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, Yaoundé P.O. Box 812, Cameroon
Rémy Bertrand Teponno
Department of Chemistry, Faculty of Science, University of Dschang, Dschang P.O. Box 67, Cameroon
Bruno Ndjakou Lenta
Department of Chemistry, Higher Teacher Training College, University of Yaoundé I, Yaoundé P.O. Box 47, Cameroon
Léon Azefack Tapondjou
Department of Chemistry, Faculty of Science, University of Dschang, Dschang P.O. Box 67, Cameroon
Arslan Ali
Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
Syed Ghulam Musharraf
HEJ, Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
This paper describes eight new triterpenoid saponins, including afzeliioside A (1), four acetylated afzeliiosides as pairs of inseparable regioisomers, called afzeliiosides B/C (2/3) and D/E (4/5), afzeliiosides F-H (6–8), and a known impatiprin C (9), which were isolated from the n-BuOH fraction of the liana of Microglossa afzelii. Their structures were established mainly by extensive spectroscopic analysis, including 1D and 2D NMR, HRFAB-MS, tandem ESI-MS/MS, and chemical methods, as well as a comparison of their spectral data with those of related compounds. All the isolates were screened for their cytotoxic activity against the CAL-27 oral squamous carcinoma cell line. Only compounds 4/5 (EC50 = 36.0 μg/mL (32.7 μM)) exhibited moderate cytotoxic activity. This work presents the first chemical and biological investigation of Microglossa afzelii and reports, for the first time, on the isolation of saponins in the genus Microglossa.
