Purification and characterization of aseanostatins: Actinomycete-derived fatty acid inhibitors to myeloperoxidase release from human polymorphonuclear leukocytes

We found inhibitors, designated aseanostatins P1 and P5, against myeloperoxidase (MPO) release from human polymorphonuclear leukocytes (PMN). Aseanostatins were extracted from an actinomycete isolated in Thailand and purified by a series of column chromatography of charcoal and silica gel, and HPLC. Physico-chemical characterization by gas liquid chromatography and GC-MS indicated that aseanostatins were fatty acids. The active forms of aseanostatins were recovered by hydrolyzing their methyl esters after HPLC. Two components P1 and P5 with the IC₅₀ of 0.96 and 0.54 μg/ml to the MPO release were obtained as pure forms, indicating aseanostatin P5 was higher activity than aseanostatin P1. The component P1 was identical with 12-methyltridecanoic acid and P5 was indistinguishable to 12-methyltetradecanoic acid (ante-i-15:0). Aseanostatin P5 (1 μg/ml) did not inhibit β-glucuronidase release, but O₂ ^- production a little. It has no effect on chemotaxis of PMN to fMet-Leu-Phe (10^-8 M), PMN adhesion or phosphorylation of a 64-kD protein in the PMN cell-lysate system.