Characterization and evaluation of bioactive polyphenolic constituents from Zanthoxylum armatum DC., a traditionally used plant

- Three flavonoids namely Tambulin, Prudomestin, Ombuin from the fruits of Zanthoxylum armatum were identified and characterized.
- The extracts of fruit and the characterized flavonoids were found to reveal significant antioxidant potential.
- Tambulin exhibited significant anti-proliferative activity against selected cancer cell lines.
- Ombuin was found to possess broad spectrum antibacterial effect.

Zanthoxylum armatum or Timoor has been used in different traditional system of medicine due to its aromatic properties and also in the treatment of cancer, diarrhea and cholera. In the present investigation, four chemically distinct compounds namely Tambulin (6), Prudomestin (7), Ombuin (8) and 3, 4, 5, 3′, 4′, 5′-hexahydroxydiphenyl ether (9) have been isolated and quantified from the fruits. To explore the biological activities, we have further studied the antiproliferative, antimicrobial and antioxidant efficacy. Tambulin which was also found in maximum amount (0.125%) in fruits revealed significant antiproliferative activity (IC50 37.96 ± 0.36 to 48.7 ± 0.21 μg/mL) against breast, liver, colon and skin cancer cell lines corroborated by resilient binding interaction with SDH (−6.76 Kcal/mol) and inhibition constant (Ki: 11.02 μM). Hexane and ethyl acetate fraction exhibited moderate antibacterial efficacy (MIC: 250-1000 μg/mL) against selected pathogenic microbes while Ombuin displayed broad spectrum antibacterial effect with MIC ranges from 125 to 500 μg/mL. Total phenolic content (5.27 ± 0.06 to 46.12 ± 0.40 mg/g of gallic acid equivalents), total flavonoids content (6.05 ± 0.24 to 14.46 ± 0.73 mg/g of quercetin equivalents), ferric reducing power (42.35 ± 0.85 to 62.52 ± 0.66 mg/g of ferrous sulfate equivalents) and percent free radical scavenging activity (59.56 ± 0.38 to 64.85 ± 1.78) were also estimated. Our findings infer that Tambulin exhibited significant antiproliferative activity whereas Ombuin was found to display broad spectrum antibacterial activity which adds one more positive attribute to its traditional usage.

195