Acid Induced Phytoconstituents of Calotropis procera Extract Combined with Ampicillin in Combating Clinical Resistant Isolates of Staphylococcus aureus and Salmonella spp.

Abstract

Natural products, with their inherent diversity, offer unique pharmacophores, chemotypes, and scaffolds that can be harnessed to create effective drugs targeting various infections and diseases. This study introduces a straightforward, rudimentary, and environmentally sustainable method to enhance the antimicrobial activity of two less potent antimicrobial agents, fostering synergism against drug-resistant clinical bacteria. The aqueous extract of fresh leaves and flowers of Calotropis procera was subjected to a reaction with a 1 mg/mL ampicillin solution, resulting in synergy and heightened susceptibility against resistant strains of Staphylococcus aureus and Salmonella spp., augmenting their zones of inhibition from 0 mm to 16.8 mm and from 5.3 mm to 21.4 mm, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis identified 53 phytochemicals in C. procera extract, revealing oleic acid (13.04%), 1,1,1,3,5,5,7,7,7-nonamethyl-3-(trimethylsiloxy) tetrasiloxane (9.50%), 9-heptadecanone (3.75%), cystamine (3.35%), and tetrahydro-4H-pyran-4-ol (3.15%) as the top five most abundant phytochemicals. Notably, 18 out of the 53 phytochemicals were associated with known reported biological activities. The analysis revealed the discovery of compounds such as farnesol, cystamine, cystine, metaraminol, dl-phenylephrine, and two distinct substituted amphetamine compounds. Three phytochemicals demonstrated anticancer properties, namely farnesol, 4-amino-1-pentanol, and an imidazole derivative resembling the drug Ribavir. These compounds may serve as valuable starting materials, intermediates, or derivatives in pharmaceutical production.