|KUMAR, ANAND - Indian Institute Of Technology|
|Kuo, Tsung Min|
Submitted to: Bioresource Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/5/2008
Publication Date: 11/1/2009
Citation: Khare, S.K., Kumar, A., Kuo, T. 2009. Lipase-catalyzed production of a bioactive fatty amide derivative of 7,10-dihydroxy-8(E)-octadecenoic acid. Bioresource Technology. 100(3):1482-1485.
Interpretive Summary: Surplus vegetable oils represent attractive renewable resources for the production of useful chemicals. Previously, we investigated the enzymatic reaction parameters for directly adding ammonia to the reactive terminal of common fatty acids and their derivatives to form a group of compounds called primary fatty amides with enhanced ability to undergo chemical reactions. In this study, we further modified a bioproduct derived from oleic acid, a common fatty acid of renewable plant lipids, by the same enzymatic process to produce a new product called secondary fatty amide. The production reaction was characterized and optimized. The resulting new secondary fatty amide displayed potent antimicrobial activities and also exhibited moderate levels of an antioxidative activity. The impact of this study provides new information for scientists to develop new products from low cost vegetable oils and search for their potential new uses.
Technical Abstract: Fatty amides are of considerable interest due to their wide ranging industrial applications in detergents, shampoo, cosmetics and surfactant formulations. They are produced commercially from fatty acids by reacting with anhydrous ammonia at approximately 200 deg C and 345-690 KPa pressure. We investigated the potential of Candida antarctica lipase B (CALB) under mild conditions to catalyze direct amidation of carboxylic acid in organic solvent. CALB-mediated production of a novel secondary amide was carried out by reacting the oleic acid conversion bioproduct, 7,10-dihydroxy-8(E)-octadecenoic acid (DOD), with N-methylethanol amine as nucleophile in a selected organic solvent. A single, new product peak corresponding to the secondary amide of DOD (D2AM) was detected by high-performance liquid chromatography and thin-layer chromatography. The production of D2AM was achieved in high yields (95%) after 72 h at 50 deg C and atmospheric pressure in a CALB-catalyzed reaction that contained 100 IU enzyme activity, 50 mM DOD, and 100 mM N-methylethanol amine in isoamyl alcohol. The new fatty amide was further investigated for its biological activity. D2AM displayed potent antimicrobial activity towards Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative bacteria (Proteus vulgaris and Klebsiella pneumonae) with minimal inhibition concentration (MIC) of 16.0, 40.0, 27.0 and 5.0 µM or of 6.0, 15.0, 10.0, and 2.0 ug/ml, respectively. D2AM also exhibited antioxidative activity by its alpha,alpha-diphenyl-beta-picryl-hydrazyl (DPPH) radicals scavenging effects.