INHIBITION OF BACTERIAL UREASE BY AUTOXIDATION OF FURAN C-18 FATTY-ACID METHYL-ESTER PRODUCTS

Autoxidation products of synthetic methyl 9,12-epoxy-octadeca-9,11-die noate (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 mM) and for commer cial urease from Bacillus pasteurii (I50 = 0.06 mM). The urease inhibi tory effect was cancelled by adding cysteine to the reaction mixture. The total content of biologically active oxidized products in the mixt ure was found to be 6.2%. Dioxo-ene derivatives of MEFA on the thin-la yer chromatography plate surface were converted into more stable compo unds, whose formation in the mixture reduced inhibition of R pasteurii to about 2% of the former level. The mechanism of urease inhibition i s supposed to involve the interaction of the thiol groups of the enzym e's active center with the inhibitor molecules.