MOLECULAR DOCKING AND INHIBITION STUDIES ON THE INTERACTION OF PROSOPIS JULIFLORA ALKALOIDS AGAINST FUSARIUM SOLANI (MART.) SACC

APARNA SRIVASTAVA¹, K.A. RAVEESHA²*
¹Centre for Innovative Studies in Herbal Drug Technology, Department of Studies in Botany, University of Mysore, Manasagangotri, Mysore-570006, Karnataka, India
²Centre for Innovative Studies in Herbal Drug Technology, Department of Studies in Botany, University of Mysore, Manasagangotri, Mysore-570006, Karnataka, India
* Corresponding Author : karaveesha@gmail.com

Received : 10-03-2016     Accepted : 17-03-2016     Published : 28-03-2016
Volume : 8     Issue : 3       Pages : 737 - 742
Int J Microbiol Res 8.3 (2016):737-742

Keywords : Prosopis juliflora, Juliprosopine, Prosopine Anti-fusarial activity, Fusarium solani, Molecular docking
Academic Editor : Biplab Kumar Das
Conflict of Interest : None declared
Acknowledgements/Funding : The authors are thankful to Department of Science and Technology, Government of India, New Delhi for financial assistance, through DST- INSPIRE Fellowship, VGST, Government of Karnataka and Institution of Excellence, University of Mysore for providing LC-MS and electron microscopy facility
Author Contribution : None declared

The alkaloid fraction of leaves of Prosopis juliflora were isolated by acid-base fractionation. The antifusarial activity of the alkaloid fractions against Fusarium solani were evaluated by disc diffusion assay and minimal inhibitory concentration (MIC). The effect of the active alkaloid fraction on F. solani mycelium and conidia was studied using mycelium growth inhibition assay, biomass production, release of cellular material, spore germination assay, light microscopy and scanning electron microscopy. The total alkaloid fraction subjected to TLC eluted 4 bands with Rf values of 0.52, 0.6, 0.81, 0.84. All the bands were subjected to antifusarial activity. Band II (Rf value 0.6) showed significant antifusarial activity with zone of inhibition of 39.3 mm and MIC of 40 µg/ml against F. solani. The LC-MS analysis of Band II indicated the presence of Juliprosopine and Prosopine. At 50 µg/ml concentration, the active alkaloid fraction showed significant reduction in mycelial growth, biomass production and spore germination which was confirmed by microscopic studies. The active alkaloid fraction also effected the fungal cell wall leading to the leakage of cellular material. Molecular docking using ligand fit protocol with Autodock tool was carried out to understand the interaction of β-glucosidase of F. solani with active alkaloid fraction to propose the possible mechanism of action for the antifusarial activity. The ligands Juliprosopine and Prosopine showed hydrogen bond interaction with active sites of the protein at minimum binding energy. The present study indicates the strong inhibition potential of the active alkaloid fraction against F. solani.