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Binding of Bioactive Phytochemical Piperine with Human Serum Binding of Bioactive PhytochemicalStudy with Human Serum Albumin: Albumin: A Spectrofluorometric Piperine A Spectrofluorometric Study
Dodda Venkatanna Suresh,1 Honsigere G. Mahesha,2 A. G. Appu Rao,2 Krishnapura Srinivasan1
1

Department of Biochemistry and Nutrition, Central Food Technological Research Institute, Mysore 570 020, Karnataka, India Department of Protein Chemistry and Technology, Central Food Technological Research Institute, Mysore 570 020, Karnataka, India Received 27 November 2006; revised 22 March 2007; accepted 23 March 2007 Published online 3 April 2007 in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/bip.20735

2

ABSTRACT:
Piperine, the bioactive alkaloid compound of the spice black pepper (Piper nigrum) exhibits a wide range of beneficial physiological and pharmacological activities. Being essentially water-insoluble, piperine is presumed to be assisted by serum albumin for its transport in blood. In this study, the binding of piperine to serum albumin was examined by employing steady state and time resolved fluorescence techniques. Binding constant for the interaction of piperine with human serum albumin, which was invariant with temperature in the range of 17–478C, was found to be 0.5 3 105MÀ1, having stoichiometry of 1:1. At 278C, the van’t Hoff enthalpy DH8 was zero; DS8 and DG8 were found to be 21.4 cal molÀ1 KÀ1 and À6.42 kcal molÀ1. The binding constant increased with the increase of ionic strength from 0.1 to 1.0M of sodium chloride. The decrease of Stern–Volmer constant with increase of temperature suggested that the fluorescence quenching is static. Piperine fluorescence showed a blue shift upon binding to serum albumin, which reverted with the addition of ligands — triiodobenzoic acid and hemin. The distance between piperine and tryptophan after binding was found to be
Correspondence to: Dr. K. Srinivasan; e-mail: [e-mail]

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