¹Department of Chemistry, Faculty of Science and Mathematics, Sultan Idris Education University, 35900 Tanjong Malim, Perak Darul Ridzuan, Malaysia
²Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
³Department of Biotechnology Engineering, Kulliyyah of Engineering, International Islamic University of Malaysia, P.O. Box 10, 50728 Kuala Lumpur, Malaysia
⁴International Institute for Halal Research and Training, International Islamic University of Malaysia, P.O. Box 10, 50728 Kuala Lumpur, Malaysia DOI : 10.12991/jrp.2019.127 Study on the chemical constituents of the dichloromethane (DCM) crude extract of Platymitra siamensis Craib has led to the isolation of four oxoaporphine alkaloids. The compounds were identified as liriodenine (1), O-methylmoschatoline (2), lysicamine (3) and cepharadione-A (4) which were isolated first time from this species. The structures of the isolated compounds were elucidated based on their spectral data (1H, 13C and LCMS) and reports in the literature. Here we observed that, only alkaloid 1 exhibited obvious cytotoxic effects against MCF-7 human breast cancer cells line with IC₅₀ value of 31.26 μM. This work is the first attempt on phytochemical and bioactivity study on the genus of Platymitra. Keywords : Platymitra siamensis ; Annonaceae ; oxoaporphine alkaloids ; MCF-7 ; cytotoxic activity