Secondary metabolites of endophytic fungi from Newbouldia laevis and Cassia tora leaves: prospecting for new antimicrobial agents

Anthonia Adaeze Amaechi; Angus Nnamdi Oli; Ugochukwu Moses Okezie; Samson A. Adejumo; Chika Christiana Abba; Ifeanyi Justin Okeke; Festus Basden Chiedu Okoye

doi:10.2174/1574891X15999201222152646

Secondary metabolites of endophytic fungi from Newbouldia laevis and Cassia tora leaves: prospecting for new antimicrobial agents

Recent Pat Antiinfect Drug Discov. 2020 Dec 22. doi: 10.2174/1574891X15999201222152646. Online ahead of print.

Authors

Anthonia Adaeze Amaechi¹, Angus Nnamdi Oli¹, Ugochukwu Moses Okezie¹, Samson A. Adejumo¹, Chika Christiana Abba², Ifeanyi Justin Okeke³, Festus Basden Chiedu Okoye²

Affiliations

¹ Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University, Awka. Nigeria.
² Department of Pharmaceutical and Medicinal` Chemistry, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University, Awka. Nigeria.
³ Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University, Awka. Nigeria.

PMID: 33355056
DOI: 10.2174/1574891X15999201222152646

Abstract

Aim: This study tries to prospect for new antimicrobial agents using some Nigerian plants Background: Antimicrobial compounds from fungi endophytes have shown great promise in mitigating the threats of resistant pathogens.

Objective: The study evaluated the in vitro antimicrobial property of secondary metabolites of endophytic fungi isolated from Newbouldia laevis and Cassia tora leaves.

Methods: Ten endophytic fungi were isolated from the two plants' leaves and later fermented on local rice for 21 days. Thereafter, their secondary metabolites were extracted using ethyl acetate. The antibacterial activity of the extracts on the test organisms were determined using agar diffusion and agar dilution methods, while the bioactive constituents were identified using High performance liquid chromatography coupled to diode array detector.

Results: Nine of the crude extracts (NL1, NL3, NL6, NL10, NL12, CT2, CT7, CT9 and CT10) of the fungi isolates inhibited at least one of the microorganisms studied with maximum and minimum Inhibition-Zone-Diameter of 14 mm and 2 mm respectively while CT1 did not inhibit any of the tested microorganisms at tested concentrations. The extracts exhibited good antifungal activity, inhibiting the growth of both C. albicans and Trichophyton tested with an InhibitionZone-Diameter ranging between 4-8 mm and 7-14 mm respectively. The endophytic fungi extracts- CT2 and NL1- exhibited the best antimicrobial activity, inhibiting most of the tested microorganisms. HPLC-DAD analysis of the endophytic fungal extracts identified some classes of compounds such as catechin derivatives, benzoic acid derivatives and apigenin, which were previously reported to have antimicrobial potentials.

Conclusion: Newbouldia laevis and Cassia tora leaves house endophytic fungi capable of yielding secondary metabolites with potential as anti-infective agents.

Keywords: (Fungal Secondary metabolites; Antimicrobial properties; Cassia tora; Fungal Endophytes; Newbouldia laevis; Nigerian plants).