Structural Elucidation and Antimicrobial Analysis of Bioactive Compounds from Amaranthus spinosus

Abstract

Amaranthus spinosus is a herb which belongs to the Amaranthaceae family and used by ethnic people in the treatment of various infections and ailments. As a result of its medicinal properties, it is gaining the attention of many researchers. This research work was carried out to isolate the compounds present in the leaves of Amaranthus spinosus, characterize, use obtained data to validate its bioactivity. The crude extract was obtained using methanol in a Soxhlet extractor. The pure extracts were isolated from the crude extracts using column chromatography and further purification was done using Sephadex. The structures of the isolates were elucidated using nuclear magnetic Resonance Spectroscopy. In the validation of the bioactivity of the plant, some pathogens were used, including Escherichia coli, Bacillus species and Pseudomonas aeruginosa, Candida albicans and Aspergillus niger. The antimicrobial analysis carried out using two isolates from the plant extracts indicated the following zones of inhibition (mm) for the first isolate: 16.00 ± 0.01, 16.00 ±0.01, 15.00 ± 0.08, 16.00±0.08, 17.00 ± 0.08. For the second isolate, the diameter zone of inhibition (mm) includes 6.00±0.08, 5.00± 0.10, 26.00± 0.10, 5.00±0.08, and 16.00±0.10. These results were compared with a standard antibiotic, ciprofloxacin, and standard antifungal, ketoconazole. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) of the isolated compounds were determined and compared with those of the standard drugs.