Inhibition of bacterial urease by autoxidation of furan C‐18 fatty acid methyl ester products

Abstract

501Autoxidation products of synthetic methyl 9,12-epoxyoctadeca-9,11-dienoate (MEFA) were investigated by gas chromatography-mass spectrometry analysis and tested for bacterial urease inhibition. A suspension of oxidized MEFA in 10% Tween 80 was an effective inhibitor for bacterial urease extract from Helicobacter pylori (I50 --1.3 raM) and for commercial urease from Bacillus pasteurii (I50 --0.06 mM}. The urease inhibitory effect was cancelled by adding cysteine to the reaction mixture. The total content of biologically active oxidized products in the mixture was found to be 6.2%. Dioxo-ene derivatives of MEFA on the thin-layer chromatography plate surface were converted into more stable compounds, whose formation in the mixture reduced inhibition of B. pasteurii to about 2% of the former level. The mechanism of urease inhibition is supposed to involve the interaction of the thiol groups of the enzyme's active center with the inhibitor molecules.

Characterisation of furan fatty acids in Adriatic fish

“…It has been pointed out that they act as antioxidants as they prevent linoleic acid oxidation (Okada et al, 1990) and as antioxidants in plants (Batna & Spiteller, 1994). Additionally, F-acids have been reported to have inhibitory effects on blood platelet aggregation (Graff, Gellermann, Sand, & Schlenk, 1984) on bacterial urease activity (Rosenblat, Tabak, Lie Ken Jie, & Neeman, 1993) and to have potential antitumor activity (Isoda et al, 1993). F-acids with an unsaturated (olefinic) side chain have also been identified in food matrices such as butter fat (Guth & Grosch, 1992) and olive oil (Boselli, Grob, & Lercker, 2000).…”

Synthesis and nuclear magnetic resonance properties of all geometrical isomers of conjugated linoleic acids

“…There is considerable interest in conjugated linoleic acids (CLA), a mixture of geometric isomers of 18:2 (9,11), which show unique biological properties. These fatty acids are recognized as special nutrients that function to regulate energy retention and protein metabolism in animals (1).…”

“…The anticancer proper-ties of CLA may be related to products formed by autoxidation of the substrates. There is speculation that CLA may cyclize to form furan fatty acids, as the autoxidized products of furan fatty acids have been shown to inhibit urease enzyme activities (11).…”

“…Many of the abovementioned procedures give rise to mixtures of the conjugated dienoic acids. Our objective in this project was to produce the four geometric isomers of 18:2 (9,11) in the pure form and to study their NMR properties.…”