Germinating seeds of Tamarindus indica synthesizes various enzymes which are required for the degradation of seed reserves such as xyloglucans, fatty acid esters and proteins. Among these, esterases, belonging to a group of hydrolytic enzymes catalyze the hydrolysis of various types of esters. They play an important role in cell expansion as well as detoxification of xenobiotics and many agrochemicals and insecticides. The esterases are extracted from the germinating tamarind seeds using 50 mM phosphate buffer, pH 7. The Km with α-naphthyl acetate as the substrate is 19.23 μM and the enzymes are optimally active at pH 7.0 to 7.5 and are stable between pH 5.0 to 9.0. The optimum temperature of esterase activity of tamarind seed is between 37?C - 50?C and is stable up to 40?C. The activity declined by 30% at 60?C and about 90% at 70?C. Highest esterase activity and specific activity are observed on the 21st day of germination. The polyacrylamide gel electrophoresis (PAGE) indicated the presence of nine isozymes of esterases. Band numbers 1, 5 and 6 are the major esterolytic bands present throughout the germination period while band numbers 2 & 3 are minor bands present only during the latter period of the germination. Based on substrate and inhibitor specificity in conjunction with electrophoresis, the esterases 1 to 8 have been classified as carboxylesterases sensitive to organophosphate inhibitor (OP) and PCMB (p-chloromercuribenzoate) while esterase 9 is classified as carboxylesterase sensitive to OP. These esterases are unaffected by carbamate inhibitor, eserine sulphate.
 Jung, Y.J., Lee, J.K., Sung, C.G., Oh, T.K. and Kima, H.K. (2003) Nonionic Detergent Induced Activation of an Esterase from Bacillus megaterium 20-1. Journal of Molecular Catalysis B: Enzymatic, 26, 223-229. http://dx.doi.org/10.1016/j.molcatb.2003.06.006
 Potter, P.M. and Wadkins, R.M. (2006) Carboxylesterases: De-toxifying Enzymes and Targets for Drug Therapy. Current Medicinal Chemistry, 13, 1045-1054. http://dx.doi.org/10.2174/092986706776360969
 Abernathy, C.O. and Casida, J.E. (1973) Pyrethroid Insecticides: Esterase Cleavage in Relation to Selective Toxicity. Science, 179, 1235-1236. http://dx.doi.org/10.1126/science.179.4079.1235
 Wheelock, C.E., Miller, J.L., Miller, M.G., Shan, G., Gee, S.J. and Hammock, B.D. (2004) Development of Toxicity Identification Evaluation (TIE) Procedures for Pyrethroid Detection Using Esterase Activity. Environmental Toxicology and Chemistry, 23, 2699-2708. http://dx.doi.org/10.1897/03-544
 Van Asperen, K. (1962) A Study of House Fly Esterase by Means of a Sensitive Colorimetric Method. Journal of In- sect Physiology, 8, 401-416. http://dx.doi.org/10.1016/0022-1910(62)90074-4
 Davis, B.J. (1964) Disc Electrophoresis-II Method and Application to Human Serum Proteins. Annals of the New York Academy of Sciences, 121, 404-427. http://dx.doi.org/10.1111/j.1749-6632.1964.tb14213.x
 Ornstein, L. (1964) Disc Electrophoresis. I. Background and Theory. Annals of the New York Academy of Sciences, 121, 321-349. http://dx.doi.org/10.1111/j.1749-6632.1964.tb14207.x
 Hunter, R.L. and Markert, C.L. (1957) Histochemical Demonstration of Isozymes Separated by Zone Electrophoresis in Starch Gels. Science, 125, 1294-1295. http://dx.doi.org/10.1126/science.125.3261.1294-a
 Subramani, T., Manjunath, K.C., Siddalinga Murthy, K.R. and Ramachandra Swamy, N. (2012) Esterase Activity from the Germinated Jatropha curcas Seeds in Different Extraction Buffers. International Journal of Science and Nature (IJSN), 3, 170-172.
 Walker, C.H. and Mackness, M.I. (1983) Esterases: Problems of Identification and Classification. Biochemical Pharmacology, 32, 3265-3326. http://dx.doi.org/10.1016/0006-2952(83)90349-0
 Holmes, R.S. and Masters, C.J. (1967) The Developmental Multiplicity and Isoenzyme Status of Cavian Esterases. Biochimica et Biophysica Acta, 132, 379-399. http://dx.doi.org/10.1016/0005-2744(67)90157-X
 Coates, P.M., Mestriner, M.A. and Hopkinson, D.A. (1975) A Preliminary Genetic Interpretation of the Esterase Iso- zymes of Human Tissues. Annals of Human Genetics, 39,1-20. http://dx.doi.org/10.1111/j.1469-1809.1975.tb00103.x
 Healy, M.J., Dumancic, M.M. and Oakeshott, J.G. (1991) Biochemical and Physisological Studies of Soluble Esterases from Drosophila melanogaster. Biochemical Genetics, 29, 365-388. http://dx.doi.org/10.1007/BF00554144
 Sreerama, L. and Veerabhadrappa, P.S. (1991) Purification and Properties of Carboxylesterases from the Midgut of the Termite Odentotermes horni. Insect Biochemistry, 21, 833-844. http://dx.doi.org/10.1016/0020-1790(91)90090-2
 Siddalinga Murthy, K.R. and Veerabhadrappa, P.S. (1996) Purification, Characterization and Properties of Carbox- ylesterase from the Midgut of the Silkworm, Bombyx mori L. Insect Biochemistry and Molecular Biology, 26, 287-296. http://dx.doi.org/10.1016/0965-1748(95)00091-7