Phytochemical Investigation and Biological Studies on Selected <i>Searsia</i> Species

Mkhuseli Koki; Masande Yalo; Masixole Makhaba; Ndikho Nako; Fanie Rautenbach; Jelili A. Badmus; Jeanine Marnewick; Ahmed A. Hussein; Wilfred T. Mabusela

doi:10.3390/plants11202793

Plants (Oct 2022)

Phytochemical Investigation and Biological Studies on Selected <i>Searsia</i> Species

Mkhuseli Koki,
Masande Yalo,
Masixole Makhaba,
Ndikho Nako,
Fanie Rautenbach,
Jelili A. Badmus,
Jeanine Marnewick,
Ahmed A. Hussein,
Wilfred T. Mabusela

Affiliations

Mkhuseli Koki: Department of Chemistry, University of the Western Cape, Private Bag X17, Bellville 7538, South Africa
Masande Yalo: Department of Chemistry, University of the Western Cape, Private Bag X17, Bellville 7538, South Africa
Masixole Makhaba: Department of Chemistry, University of the Western Cape, Private Bag X17, Bellville 7538, South Africa
Ndikho Nako: Department of Chemistry, University of the Western Cape, Private Bag X17, Bellville 7538, South Africa
Fanie Rautenbach: Applied Microbial and Health Biotechnology Institute, Cape Peninsula University of Technology, Symphony Rd., Bellville 7535, South Africa
Jelili A. Badmus: Applied Microbial and Health Biotechnology Institute, Cape Peninsula University of Technology, Symphony Rd., Bellville 7535, South Africa
Jeanine Marnewick: Applied Microbial and Health Biotechnology Institute, Cape Peninsula University of Technology, Symphony Rd., Bellville 7535, South Africa
Ahmed A. Hussein: Chemistry Department, Cape Peninsula University of Technology, Symphony Rd., Bellville 7535, South Africa
Wilfred T. Mabusela: Department of Chemistry, University of the Western Cape, Private Bag X17, Bellville 7538, South Africa

DOI: https://doi.org/10.3390/plants11202793
Journal volume & issue: Vol. 11, no. 20
p. 2793

Abstract

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Searsia is the more recent name for the genus Rhus, which contains over 250 individual species of flowering plants in the family Anacardiaceae. Several Searsia species are used in folk medicine and have been reported to exhibit various biological activities. Although known to exhibit different terpenoids and flavonoids, the chemistry of the Searsia genus is not comprehensively studied due to the structural complexity of the compounds. In this study, the extraction, isolation, and identification of secondary metabolites from three Searsia species (Searsia glauca, S. lucida, and S. laevigata) were conducted using chromatographic and spectroscopic techniques and afforded five known terpenes, viz., moronic acid (1), 21β-hydroxylolean-12-en-3-one (2), lupeol (11), α-amyrin (9), and β-amyrin (10), in addition to six known flavonoids, myricetin-3-O-β-galactopyranoside (3), rutin (4), quercetin (5), apigenin (6), amentoflavone (7), and quercetin-3-O-β-glucoside (8). The structural elucidation of the isolated compounds was determined based on NMR (1D and 2D) and comparison with the data in the literature. Biological assays, such as antioxidant and enzyme inhibition activity assays, were conducted on the plant extracts and the isolated compounds. The antioxidant capacities of hexane, dichloromethane, ethyl acetate, methanol, and butanol main extracts were investigated using ferric ion reducing power (FRAP), oxygen radical absorbance capacity (ORAC), and Trolox equivalent antioxidant capacity (TEAC) assays. The results showed high antioxidant activities for methanol and butanol extracts of the three plants. The isolated compounds were tested against alpha-glucosidase and alpha-amylase, and the results showed the potent activity of moronic acid (C1) (IC50 10.62 ± 0.89 and 20.08 ± 0.56 µg/mL, respectively) and amentoflavone (C7) (IC50 5.57 ± 1.12 µg/mL and 19.84 ± 1.33 µg/mL, respectively). Isolated compounds of and biological assays for S. glauca, S. lucida, and S. laevigata are reported for the first time.

Published in Plants

ISSN: 2223-7747 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Science: Botany
Website: http://www.mdpi.com/journal/plants

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