ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Enzymatic synthesis and analytical monitoring of terpene ester by ¹H NMR spectroscopy

Dipak Patil, Debabrata Das, and Ahindra Nag

Department of Chemistry, Indian Institute of Technology, Kharagpur, 721302 India

E-mail: ahinnag@chem.iitkgp.ernet.in

Abstract: Terpene esters of fatty acids have potential applications in food, cosmetic, and pharmaceutical industries. The present study focuses on the synthesis of terpene esters of long chain fatty acids catalyzed by Candida antarctica lipase B. Different parameters like temperature, solvent, and enzyme concentration for the esterification of terpene alcohols (geraniol and citronellol) with oleic acid were studied. Maximum conversion (98 %) was found for both terpene esters at 60°C in 2,2,4-trimethylpentane as well as in dry hexane and around 95–97 % in other tested solvents. The reaction was also carried out using stearic and linoleic acid in hexane to study the effects of unsaturation in the substrate in which stearic acid showed the maximum conversion. The reaction was monitored by ¹H nuclear magnetic resonance spectroscopy. Using the peak integration values of methylene protons of terpene and terpene ester of δ = 3.6 and 4.0 for citronellol and δ = 4.2 and 4.6 for geraniol, respectively, percentage conversions of each of the esters were calculated.

Keywords: terpene – fatty acid – esterification – lipase – quantification – NMR

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-010-0077-8

Chemical Papers 65 (1) 9–15 (2011)