MICROBIAL DIVERSITY OF COMMERCIALLY IMPORTANT ENZYMES 77 Malays. Appl. Biol. (2013) 42(1): 77–81 * To whom correspondence should be addressed. STUDIES ON THE MICROBIAL DIVERSITY OF COMMERCIALLY IMPORTANT ENZYMES FOR ENANTIOSELECTIVE TRANSFORMATIONS ON A NEW RANGE OF 4-ARYL-1, 4-DIHYDROPYRIDINES KAUR, A. 1 , BANSAL, R. 2 and KAUR, J. 1* 1 University Institute of Engineering and Technology, Panjab University, Chandigarh, India. 2 University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India. * E-mail: jaspreet_virdi@yahoo.com ABSTRACT A new series of 4-aryl-1, 4-dihyropyridines possessing potent calcium channel blocking activity along with good vasodilatory profile by the modified Hantzsch condensation using trifluoroacetic acid as catalyst has been synthesized and reported from our laboratory. The present work describes chemo enzymatic approach for the enantioselective hydrolysis of a 1, 4- dihydropyridine skeleton. In this study, lipases have been recognized as very useful biocatalyst. Diverse range of organisms including bacteria, fungi have been studied for extracellular enzyme production. Growth of the organisms and lipase production were measured at various intervals of time. Lipases from all the sources were assayed for at various temperatures ranging from 15 to 45ºC and pH in the range of 3.0 to 9.0. Variation of enzyme activity with substrate concentration has also been investigated. The lipases from above sources have been studied for their potential of enantioselective catalysis with the newly synthesized dihydropyridine diesters to obtain enantiopure products. Optical yields were confirmed with the help of polarimeter and HPLC analysis is being studied presently. The methodology for higher yields will be developed which could lead to production of optically active calcium channel blockers. Key words: dihydropyridines, calcium channel blockers, chemoenzymatic synthesis, transformations INTRODUCTION Among the various calcium antagonists, dihydropyridines form the most important class of these compounds due to their high potency. Calcium antagonists have been introduced into clinical medicine over the last few decades. They interact specifically at one locus of cellular calcium regulation: the L-type calcium channel. In the absence of appropriate control mechanisms, calcium would be involved in events like cell destruction and death (Mannhold, 1994). Dihydropyridines belong to the class of nitrogen containing heterocycles having a six-membered ring (Fig. 1). This class of compounds shows fascinating spectra of pharmacological and therapeutic effects because of the heterogeneity involved in their chemical structure. 1, 4-Dihydropyridines exhibit a broad range of activities such as blocking of L-type calcium channels for the treatment of cardiovascular disorders, neuroprotective and antineurodegenerative, memory enhancing, antiviral and anti-inflammatory activities (Sobolev et al., 2004). Many other properties displayed by 1,4-dihydropyridines include calcium channel modulation (Triggle, 2003), antidiabetic (Briede, 1999), geroprotective (Emanuel, 1985) and hepatoprotective (Bird, Fig. 1. Basic ring structure of dihydropyridines. R 1 and R 2 are different alkyl groups.