Identification and quantification of secondary metabolites and the antimicrobial efficacy of leaves extracts of some medicinal plants

Abstract EN

Azadirachta indica, Calotropis procera, Carica papaya, and Vernonia amygdalina are among the most frequently used plants with proven ethnomedicinal applications in Ilorin, Nigeria.

This study investigated the active constituents and antimicrobial efficacy of acetone and aqueous extracts of these plants against Candida albicans, Escherichia coli ATCC 259220, and Staphylococcus aureus ATCC 25923 by the disc diffusion technique.

High-Performance Liquid Chromatography (HPLC) fingerprint of the constituents of acetone extracts of C.

papaya, A.

indica, and V.

amygdalina was further investigated.

Highest percentage yield (10.20 %) was obtained for acetone extract of A.

indica while the lowest yield (10.20 %) was obtained for aqueous extract of C.

papaya.

Varying constituents viz.

coumarins, glycosides, protein, saponin, anthraquinone, flavonoid, tannin and terpenoid were detected.

Different levels of antimicrobial efficacy were exhibited by each of the plants while a synergistic effect was observed at 100 mg/mL concentration of acetone extract of the combination of all the plants.

An array of compounds was separated at different peak heights corresponding to concentration of the compounds.

Creptolepinone was detected in highest percentage (47.0 %) in acetone extracts of C.

papaya while phorbolester was detected in lowest percentage (1.2 %).

Myricetin was detected in highest percentage (39.6 %) in acetone extracts of A.

indica while alpha funebren was detected in lowest percentage (1.5 %).

Vernodalin was detected in highest peak height (48.8 %) in V.

amygdalina and andrographoside was detected in lowest peak height (0.6 %).

This study depicts that the plants may be promising pharmaceutical candidates that can be used in the development of new therapeutic agents.