Isolation, characterization, antibacterial activity and in silico studies of the isolated flavonol from Indigofera welwitschii
DOI:
https://doi.org/10.51412/psnnjp.2026.012Keywords:
Glycoside, Indigofera welwitschii, Phytochemical, QuercetinAbstract
Background: Inflammation and skin infections pose significant health risks in both rural and urban areas, primarily due to poor hygiene, limited access to healthcare, and unsanitary conditions. Rural regions often lack medical facilities that provide timely treatment, while urban areas with high population density can worsen the spread of infections. These factors may lead to serious skin conditions that negatively affect individuals' quality of life. In Katsina State, Nigeria, the local population traditionally uses Indigofera welwitschii to manage skin problems related to inflammation and bacterial infections. This research objectives were to isolate, characterize, evaluate and investigate compounds for potential antihistamine and anti-inflammatory properties in an in silico molecular docking model against GBM EGFR from the ethyl acetate fraction of the methanol extract of the aerial parts of Indigofera welwitschii.
Method: This involved the use of 2.2 kg of dried and powdered plant material, which was exhaustively extracted with methanol. The resulting methanol extract was suspended in distilled water and successfully divided into different fractions: hexane (HEF), ethyl acetate (EAF), chloroform (CHF), n-butanol (NBF), and aqueous (AQF) portions. The ethyl acetate fraction, weighing 10 g, was subjected to column chromatographic separation with silica gel using a gradient elution method. This was followed by repeated gel filtration on Sephadex LH-20 and preparative thin-layer chromatography. The structures of the isolated compounds were determined using various chemical and spectroscopic methods, including 1H and 13C NMR. Among the isolated compounds, only one was obtained in high yield and evaluated for antimicrobial activity against selected dermatophytes and also through in silico assessment. The agar well diffusion technique was employed to assess the antibacterial activity of the isolated compound.
Results: Quercetin and a quercetin glycoside (7-O-Prenylquercetin-3'-methoxy-3-O-α-d-glucopyranoside) were identified. The bacterial inhibition observed was minimal but highest against Escherichia coli. Computational analysis using AutoDock Vina in PyRx yielded docking scores of -6.2, which is lower than that of the standard drugs.
Conclusion: This is the first successful extraction of these specific flavonols, accompanied by comprehensive in silico analyses derived from this plant species in the establishment of its ethnomedicinal claims.
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