Evaluation of antioxidant activity, antibacterial potential and characterization of active fraction of Dioscorea pentaphylla L. tuber extract collected from Similipal Biosphere Reserve, Odisha, India

Running title: Bioactivity of active fraction of Dioscorea pentaphylla L. tuber

Sanjeet Kumar¹, Padma Mahanti², NiharRanjan Singh¹, Sakti Kant Rath³, Padan Kumar Jena¹, and Jayanta Kumar Patra^4*,

¹Department of Botany, Ravenshaw University, Cuttack-753003, Odisha, India, ²Department of Environment and Climate Change, Trivandrum-695024, Kerala, India, ³School of Life Sciences, Ravenshaw University, Cuttack-753003, Odisha, India, ⁴Research Institute of Biotechnology & Medical Converged Science, Dongguk University-Seoul, Goyang-si, Gyeonggi-do 10326, Republic of Korea

*Correspondence:

J. K. Patra

Research Institute of Biotechnology & Medical Converged Science

Dongguk University-Seoul

Goyang-si, Gyeonggi-do 10326, Republic of Korea

E-mail: jkpatra@dongguk.edu

Ph: +82-31-961-5625

ABSTRACT

Dioscorea pentaphylla L., a wild tuber is used both as food and medicines among the different ethnic groups of the Similipal Biosphere Reserve, India. Tubers are used against skin infections. In order to establish and confirm the tribal claims, methanol extract was subjected to fractionation. The active fraction (DP1) was subsequently used for further purification and NMR (Nuclear magnetic resonance) characterization.  The phytochemical analysis revealed the presence of saponin groups. The antibacterial activity of DP1 was done against selected bacterial strains (Salmonella typhi, Shigella flexneri, Streptococcus pyogenes, Streptococcus mutans and Vibrio cholerae) using DD (disc diffusion), AWD (agar well diffusion) and broth dilution assay. The activity was compared with antibiotics Penicillin and Kanamycin. It was observed that DP1 showed significant inhibitory activity against the tested bacterial strains. The characterization of DP1 through NMR analysis and presence of proton in carbon position at C-3, C-19, C-18, C-21 and C-27 was same as the known compound Diosgenin. Therefore, the isolated compound was confirmed to be Diosgenin. The study for the first time established that diosgenin present in D. pentaphylla tuber was responsible for its antibacterial and antioxidant potential. Present study highlights the importance of Dioscorea species as sources of diverse secondary metabolites for the isolation of active compound(s).

Keywords: Antibacterial activity; antioxidant; compound; Dioscorea pentaphylla; NMR characterization

Accepted: Brazilian Journal of Pharmaceutical Sciences - Decision onManuscript ID BJPS-2017-0006.R3