Isolation and characterisation of methanol-soluble fraction of Alternanthera philoxeroides (Mart.) – evaluation of their antioxidant, α-glucosidase inhibitory and antimicrobial activity in in vitro systems

Abstract

Alternanthera philoxeroides (Mart.) is a tropical weed commonly known as alligator weed. It grows rapidly within a small span of time and easily available all over the world. The objective of this work was to isolate and characterise the major phenolic components present in the methanol-soluble fraction (fraction X) of A. philoxeroides leaves and to explore the biological activity (antioxidant, α-glucosidase inhibition and antimicrobial) of the fraction in in vitro system. Chromatographic (HPLC) and spectroscopic (MALDI-TOF, ¹H NMR) techniques were used to purify and characterise the phenolics present in fraction X. Five major phenolics (kaempferol, ferulic acid, salicylic acid, syringic acid and chlorogenic acid) were found in fraction X. The fraction showed anti-oxidant property, dose-dependent inhibition of α-glucosidase activity and anti-microbial activity. Hence fraction X from the weed has therapeutic potential in pathophysiological condition.

Keywords::

• Alternanthera philoxeroides
• phenolics
• antioxidant
• α-glucosidase
• antimicrobial

Acknowledgements

Thanks to Pratip Basu and Sayok Ganguli, DBT Center of Bioinformatics, Presidency College, Kolkata, for assistance in the initial stage of the work. MALDI-MS and NMR experiments were done in the central instrumental facility of Indian Institute of Chemical Biology and Indian Association of Cultivation of Science, Kolkata, India.

Notes

^1. Present address: Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, 92, Acharyya Prafulla Chandra Road, Kolkata 700 009, West Bengal, India.

^2. These authors contributed equally.

^3. Present address: Department of Botany, Jhargram Raj College, Jhargram 721 507, West Bengal, India.