Phytochemical composition and antibacterial evaluation of Tabernaemontana ventricosa Hochst. ex A. DC. leaf, stem, and latex extracts

The novel discoveries of biologically active compounds from medicinal plants have driven various research fields toward establishing essential sources of natural drug candidates. Tabernaemontana ventricosa Hochst. ex A. DC. (Apocynaceae) is a medicinal plant often used to palliate fever, treat wounds, and reduce blood pressure. The present study aimed to examine the organoleptic characters, elemental composition, phyto-chemical compounds and evaluate the antibacterial activity of the crude leaf, stem, and latex extracts of T. ventricosa. The microscopic analyses of the organoleptic characters, fluorescence analysis, and elemental composition revealed no harmful compounds. Qualitative phytochemical screening of the extracts detected alkaloids, flavonoids, saponins, sterols, steroids, phenols, fats, fixed oils, carbohydrates, and amino acids. These results correspond to the significant chemical classes observed within Tabernaemontana. The chemical composition of the crude leaf and stem, and latex extracts determined by Gas Chromatography-Mass Spec-trometry (GC-MS) analysis showed alkaloids, terpenes, phytosterols, and fatty alcohols. Major identified compounds (>1%) in all extracts were a-linolenic acid, pentadecanoic acid, a-D-mannofuranoside, methyl, 13-docosenamide, (Z)-, 9,12-octadecadienoic acid (Z, Z)-, lup-20(29)-en-3-ol, acetate, (3b), 9,19-cyclolanost-24-en-3-ol, (3b) and b-amyrin. These compounds possess pharmacological effects such as antibacterial, anti-inflammatory, and anticancer properties. The antibacterial activity was evaluated using various extracts, with different concentrations against gram-positive and gram-negative bacterial strains. Substantial antibac-terial activity of the methanolic extracts of the leaf and stem and latex extracts were observed against Bacillus subtilis (ATCC 6653), Escherichia coli (ATCC 25922), Methicillin-resistant Staphylococcus aureus (MRSA) (ATCC 43300), Staphylococcus aureus (ATCC 29213), and Pseudomonas aeruginosa (ATCC 27853) respectively. Leaf and stem hexane extracts showed considerable activity against B. subtilis and MRSA. Conversely, E. coli, MRSA, S. aureus, and P. aeruginosa displayed resistance or minimal activity at relatively low concentrations. These results suggest that the extracts of T. ventricosa have a substantial antibacterial activity that justifies their use in traditional medicine. Further studies should be considered to establish the full pharmacological potential of this species.(c) 2022 SAAB. Published by Elsevier B.V. All rights reserved.