Phytochemical investigation of wild and cultivated Pterocarpus angolensis

Pterocarpus angolensis (Family: Fabaceae) is an indigenous medicinal plant found in east and southern Africa [1]. P. angolensis is used for the treatment of stomach troubles, diarrhoea, fevers, mouth ulcers, nose bleeding, sore eyes, and skin problems [2]. The phenolic compounds of the Pterocarpus genus were found to exhibit antimicrobial, anti-inflammatory, and antioxidant activities [3]. Limited phytochemistry of P. angolensis was carried out; hence, further investigation is needed. In this study, the main focus was to isolate natural compounds from the stem bark of P. angolensis and determine their in vitro anticancer activities. The wild and cultivated powdered stem bark of P. angolensis was extracted sequentially with increasing polarity from hexane, dichloromethane, ethyl acetate, and methanol. The DCM crude extracts were loaded on column chromatography for fractionation. Fractions were collected based on the TLC profile and Rf values and further purified using the preparative TLC method. The stem bark of Pterocarpus afforded seven compounds namely, Friedelin (1), 3α-Hydroxy-2-oxofriedelane (2), 3-Hydroxy-2-oxofrediel-3-ene (3), lupeol (4), 4-O-methylangolensin (5) Tridecyl ferulate (6) and stigmasterol (7). The structures of the isolated pure compounds were elucidated and identified using spectroscopic methods such IR, MS, 1D and 2D NMR and by comparison of literature values. The crude extracts and isolated compounds were screened against breast cancer cell lines (MCF-7) and normal cells (Vero). Compound 5, wild CDM extract, cultivated DCM extract and wild hexane extract showed selective anticancer activities with LC50 values of 48.11, 44.30, 13.50 and 206.97 µg/mL, respectively.

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• References

• 1 Mojeremane W, Lumbile AU. A Review of Pterocarpus angolensis DC. (Mukwa) an important and threatened timber species of the miombo woodlands. J For Res 2016; 10: 8-14
• 2 Van Wyk B, Van Wyk P. Field guide to trees of southern Africa. Cape Town: Struik Publishers (Pty) Ltd.; 1997: 462-463
• 3 Abouelela ME, Abdelhamid RA, Orabi MAA. Phytochemical constituents of plant species of Pterocarpus (F: Leguminosae): A review. IJPPR 2019; 11 (04) 264-281

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Artikel online veröffentlicht:
12. Dezember 2022