Evaluation of 5- and 6-fluoro derivatives of arachidonic acid and 5,8,14-eicosatrienoic acid as substrates and inhibitors of 5-lipoxygenase.

The 5- and 6-fluoro derivatives of arachidonic acid (5F-ETE and 6F-ETE) were evaluated as substrates of rat basophilic leukaemia cell (RBL-1) 5-lipoxygenase. 5F-ETE was found to be a poor substrate and was converted into a single product, 5-oxoeicosa-6,8,11,14-tetraenoic acid (5-oxo-ETE). 6F-ETE was a good substrate and was mainly converted into 5-hydroperoxy-6-fluoroeicosa-6,8,11,14-tetraenoic acid (5-OOH-6F-ETE) with concomitant formation of a small amount of 5-oxo-6-fluoroeicosa-6,8,11,14-tetraenoic acid (5-oxo-6F-ETE).

Use of simplified substrates for the study of 5-lipoxygenase from RBL-1 cells.

5,8,14-eicosatrienoic (5,8,14-ETA) and 5,8-eicosadienoic (5,8-EDA) acids are converted by the 5-lipoxygenase from RBL-1 cells into 5-hydroperoxy-6,8,14-eicosatrienoic (5-OOH-ETA) and 5-hydroperoxy-6,8-eicosadienoic (5-OOH-EDA) acids, respectively. These hydroperoxy fatty acids, unlike 5-hydroperoxy-6,8,11,14-eicosatetraenoic acid (5-HPETE), are not further processed into leukotrienes by the leukotriene A4 synthase activity of 5-lipoxygenase. 5,8,14-ETA was used to establish the saturation kinetics of 5-lipoxygenase in the 100,000g supernatant from RBL-1 cells.

Resolution of the enantiomers of various alpha-substituted ornithine and lysine analogs by high-performance liquid chromatography with chiral eluant and by gas chromatography on Chirasil-Val.

A reversed-phase high-performance liquid chromatography method, with L-proline and copper as chiral mobile phase, is described for the enantiomeric resolution of various alpha-substituted ornithine and lysine analogs. Although ornithine gives no separation with the chiral eluant used, excellent resolutions are obtained for various alpha-alkyl-, alpha-halogenomethyl-, alpha-vinyl-, and alpha-ethynyl-substituted ornithines. Similar separations are also observed for the dehydroornithine and lysine analogs.

Separation of the enantiomers of substituted putrescine and cadaverine analogues by gas chromatography on chiral and achiral stationary phases.

Capillary gas chromatography (GC) on chiral stationary phases, i.e., Chirasil-Val [L-valine-tert.

Chiral separation of enantiomers of substituted alpha- and beta-alanine and gamma-aminobutyric acid analogues by gas chromatography and high-performance liquid chromatography.

Gas chromatography (GC) with a chiral stationary phase, Chirasil-Val, has been used for separation of the enantiomers of several analogues of alpha- and beta-alanine as their N-trifluoroacetyl isopropyl esters. The same chiral phase GC procedure has been applied to the enantiomeric separation of various substituted gamma-aminobutyric acid analogues (GABA). Reversed-phase high-performance liquid chromatography (HPLC) with the chiral copper-L-proline complex allowed a clear resolution of all the alpha-amino acids in their underivatized forms.