Submitted to: Lipids
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2005
Publication Date: 1/31/2006
Citation: Turner, C., Wani, S., Wong, R.Y., Lin, J.T., Mckeon, T.A. 2006. Lipase-catalyzed esterification of 2-monoricinolein for 1,2(2,3)-diricinolein synthesis. Lipids. 41:(1)77-83 Interpretive Summary: Castor oil containsthe fatty acid ricinoleic acid which, because of its chemical structure, is very useful for industrial purposes. It is used in manufacturing greases, plastics, architectural coatings, and cosmetics, to name a few major applications. We plan to expand the utility of castor as an industrial by altering it to produce other chemically useful fatty acids. Therefore, we need to understand how the castor plant is able to make such an unusual fatty acid. The study reported in this manuscript provides us with the biochemical tools we need to understand an important biochemical step in castor oil synthesis. The ability to make other fatty acids in castor oil will support expanded development of bio-based products - manufactured products whose raw materials are derived from plants and other renewable sources. Such materials will retain their their environmentally friendly properties while replacing products derived from petroleum.
Technical Abstract: The purpose of this investigation was to develop conditions for producing 2-monoricinoleoyl diacylglycerols. We used lipase hydrolysis of triricinolein to obtain 2-monoricinolein and thereafter synthesized 1,2(2,3)-diricinolein through esterification of 2-monoricinolein, using ricinoleic acid as the acyl donor. Five different 1,3-specific immobilized lipases were tested for the initial methanolysis-reaction: Candida antarctica type B (CALB), Rhizomucor miehei (RML), Rhizopus oryzae lipase (ROL), Thermomyces lanuginosus (TLL) and Aspergillus niger (ANL). For the second esterification-reaction, we investigated these five lipases plus Pseudomonas cepacia (PCL), Penicillium roquefortii (PRL) Candida rugosa (CRL) and Pseudomonas fluorescens (PFL). Toluene and diisopropyl ether (DIPE) were examined as reaction media at a water activity of 0.11. ROL in DIPE gave the highest yield of 2-monoricinolein from triricinolein, 78% after three hours of reaction. The isolated 2-monoricinolein was esterified with ricinoleic acid for synthesis of 1,2(2,3)-diricinolein. ROL in DIPE gave the highest yield of 1,2(2,3)-diricinolein, 58% after one hour of reaction, and NMR analysis showed that the purity was 97.2%. This methodology can be used for synthesizing radiolabeled 1,2(2,3)-diricinolein for studying lipid biosynthesis in castor and other oilseeds.06/04/03