International Journal of Applied Microbiology and Biotechnology Research
ISSN: 2053-1818
Vol. 8(6), pp. 66-72, November, 2020
doi.org/10.33500/ijambr.2020.08.007

Antimicrobial activities of chemical constituents from the flowers of Hypericum lanceolatum Lam. (Hypericaceae)

Rolande B. Tsafack Nguemo¹, Abdel Jélil Njouendou², James D. Simo Mpetga¹, Irene Chinda Kengne³, Romeo D. Tadjouate Nago¹, Serge A. Tanemossu Fobofou⁴, Ludger A. Wessjohann⁴, Augustin Silvere Ngouela¹ and Jean-De-Dieu Tamokou³*

¹Department of Chemistry, Faculty of Science, University of Dschang, P. O. Box 67, Dschang, Cameroon.
²Department of Biomedical Science, Faculty of Health Sciences, University of Buea, P. O. Box 12 Buea, Cameroon.
³Research Unit of Microbiology and Antimicrobial Substances, Faculty of Science, University of Dschang, P. O. Box 67 Dschang, Cameroon.
⁴Department of Bioorganic Chemistry, Leibniz Institute for Plant Biochemistry, Weinberg 3, 06120, Hallee (Saale), Germany.

*To whom correspondence should be addressed. E-mail: jtamokou@yahoo.fr.

Received 06 September, 2020; Received in revised form 02 October, 2020; Accepted 07 October, 2020.

Keywords:
Hypericum lanceolatum, Bioguided fractionation, Chemical constituents, Antimicrobial activity.

The emergence of multi drug resistant bacteria and fungi has become a crucial problem in the fight against infectious diseases worldwide. Up till now, the search for new potential antimicrobial agents is a challenge. Hence, the aim of this study was to investigate the antibacterial and antifungal properties of the chemical constituents from the flowers of Hypericum lanceolatum Lam (Hypericaceae). Bioguided fractionation led to the isolation of eight known compounds (1-8) from the dichloromethane (DCM)/methanol (MeOH) (1:1; v/v) extract of the flowers of H. lanceolatum using silica gel column chromatography, preparative thin layer chromatography (TLC) and Sephadex LH-20. The structures of these compounds were determined by interpretation of their nuclear magnetic resonance (NMR) spectroscopic data, in comparison of these data with those from the literature. The crude-extract derived fractions and compounds were evaluated for their antimicrobial properties. They exhibited both antibacterial and antifungal activities with minimal inhibitory concentration (MIC) values ranging between 16 and 2048 μg/ml. Compounds 1, 2, 4 and 5 were the most active substances (MIC = 16 – 64 μg/ml), while Staphylococcus aureus and Pseudomonas aeruginosa were sensitive to all the isolated compounds. The results of the present study support the use of H. lanceolatum in traditional medicine to fight microbial infections associated with the studied microorganisms.

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