Indonesian Journal of Chemistry
Vol 22, No 6 (2022)

Structural Elucidation and Antibacterial Activity Studies of Leaf Extracts of Withania somnifera

Amsalu Genanaw Gebeyehu (Department of Chemistry, Woldia University, Woldia City, Amaraha Region, Ethiopia)
Kumlachew Zelalem Walle (Department of Chemistry, University of Gondar, Gondar, Ethiopia)
Meseret ZEbeaman Birhanu (Department of Chemistry, Debre Markos University, Debre Markos, Ethiopia)
Rahel Gebeyehu (Bacterial and Viral Diseases Research Directorate (BVDRD), Armauer Hansen Research Institute (AHRI), Jimma Road, Addis Ababa, Ethiopia)



Article Info

Publish Date
28 Oct 2022

Abstract

Withania somnifera (W. somnifera), a small, woody shrub in the Solanaceae family, has been studied using a phytochemical test, antibacterial activity and partial characterizations. Air-dried and powdered leaves of the plant were extracted with maceration over an electrical shaker using the solvent chloroform and methanol. After crude extracts of the plant were concentrated, the diffusion antibacterial susceptibility test was carried out on 25, 50, 75, and 100 mg/mL of chloroform and methanol crude extract. The bacteria used were S. aureus, S. pneumonia, E. coli, and S. typhi. Each antibacterial activity test was carried out three times. The most active crude extract of the plant was subjected to a phytochemical test and fractionation with column chromatography. Chloroform and methanol extract of the plant inhibits all cultures of four bacteria. Both chloroform and methanol extract of W. Somnifera inhibits both gram-positive and negative bacterium with a comparable inhibition zone with the standard antibiotics, amoxicillin, gentamicin, and cefoxitine. In addition, it gives a maximum inhibition zone than that of amoxicillin, starting from 25 to 100 mg/mL. Methanol extract of W. somnifera contains phenolic, alkaloids, flavonoids, tannins, and phytosteroids. Partial characterization of pure fractions by using 1H-NMR, 13C-NMR, Dept-135 NMR, and IR spectroscopy, the compound WS-1 affords withaferin A. Withaferine A shows antibacterial activity with an inhibition zone of 11, 10.5, 11, and 9 mm against the bacterium S. aureus, S. pneumoniae, E. coli, and S. typhi respectively.

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Journal Info

Abbrev

ijc

Publisher

Subject

Chemical Engineering, Chemistry & Bioengineering Chemistry

Description

Indonesian Journal of Chemistry is an International, peer-reviewed, open access journal that publishes original research articles, review articles, as well as short communication in all areas of chemistry including applied chemistry. The journal is accredited by The Ministry of Research, Technology ...