Antimalarial and cytotoxic activities of pregnene-type steroidal alkaloids from Holarrhena pubescens roots

• Main Authors: Sarot Cheenpracha, Pannakorn Boapun, Thunwadee Limtharakul (née Ritthiwigrom), Surat Laphookhieo, Stephen G. Pyne
• Format: Journal
• Published: 2018
• Subjects: Agricultural and Biological Sciences; Biochemistry, Genetics and Molecular Biology; Chemistry
• Online Access: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85034848291&origin=inward; http://cmuir.cmu.ac.th/jspui/handle/6653943832/56416
• Institution: Chiang Mai University

© 2017 Informa UK Limited, trading as Taylor & Francis Group The phytochemical investigation of an alkaloidal extract of Holarrhena pubescens roots led to the isolation and identification of a new pregnene-type alkaloid, mokluangin D (1), together with nine known steroidal alkaloids (2–10). The structure of the new metabolite was determined on the basis of spectroscopic analyses including 1D- and 2D-NMR spectroscopy and mass spectrometry. Compounds 3 and 4 showed potent antimalarial activity against Plasmodium falciparum K1 stain with IC50values of 1.2 and 2.0 μM, respectively, and showed weak cytotoxic activity against the NCI-H187 cell line with IC50values of 27.7 and 30.6 μM, respectively. The substituent groups at C-3 and the carbonyl group at C-18 are important for the activity against the P. falciparum K1 stain.