Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/21/2002
Publication Date: 1/1/2003
Citation: HOSOKAWA, M., HOU, C.T., WEISLEDER, D., BROWN, W.K. Biosynthesis of Tetrahydrofuranyl Fatty Acids. JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY. 2003. V. 80 (2). P. 145-149. Interpretive Summary: Previously, we discovered a new microbial strain ALA2 that produced seven polyhydroxy unsaturated fatty acids from linoleic acid. Hydroxy fatty acids are useful as starting materials for the synthesis of specialty chemicals, special military nylon, plastisizers, coatings, and physiologically active agents. Now, we have established one of its biosynthesis pathways. 12,13,16-Trihydroxy unsaturated fatty acid was converted to furanyl (five membered ring) fatty acids and then was further converted to 7-hydroxy furanyl fatty acid by strain ALA2. Furanyl fatty acids are known anticancer drugs. The new products have great potential to be used as bioactive agents and raw materials for synthesis of specialty chemicals. Application of these products either as agents for anti-plant pathogenic fungi or raw material for synthesis of specialty chemicals will benefit U.S. farmers.
Technical Abstract: Clavibacter sp. ALA2 converts linoleic acid into many novel oxygenated products including hydroxy fatty acids and tetrahydrofuranyl unsaturated fatty acids (THFAs). One of them was tentatively identified by GC/MS as 12,13,16-trihydroxy-9(z)-octadecenoic acid (12,13,16-THOA, Hou et al. J Am. Oil Chem. Soc. 2001). Now we are able to separate and purify 12,13,16-THOA from its isomer 12,13,17-THOA by silica gel column chromatography and by preparative thin layer chromatography. Its structure was then confirmed by proton and 13C NMR analyses. Purified 12,13,16-THOA was used as substrate to study the biosynthesis of THFAs. Within 24 h incubation, cells of strain ALA2 converted 12,13,16-THOA to both 12-hydroxy-13,16-epoxy-9(Z)-octadecenoic acid (12-hydroxy-THFA) and 7,12-dihydroxy-13,16-epoxy-9(Z)-octadecenoic acid (7,12-dihydroxy-THFA). Relative abundance of 7,12-dihydroxy-THFA increased with incubation time, while those of 12,13,16-THOA and 12-dihydroxy-THFA decreased. Therefore, the biosynthetic pathway of THFAs from linoleic acid by strain ALA2 is as follows: linoleic acid to 12,13-dihydroxy-9(Z)- octadecenoic acid to 12,13,16-THOA to 12-hydroxy-THFA to 7,12-dihydroxy-THFA.