Melanotropin-potentiating factor isolated from filtrate of uremic patients suffering from melanosis and carbohydrate intolerance

Summary Following the characterization of a hexadecapeptide,-endorphin, melanotropin-potentiating factor (MPF) was isolated from the filtrate of uremic patients suffering from melanosis and carbohydrate intolerance. The structure of MPF has been determined on the bases of chemical and physicochemical examinations which included HPLC, Edman sequence analysis combined analysis of the amino acid composition and FAB-MS analysis. An accumulation of MPF might be a cause of melanosis in uremic patients.Abbreviations Et₃N triethylamine - TFA trifluoroacetic acid - HF hydrogen fluoride - CH₃CN acetonitrile - DCC dicyclohexyl-carbidimide - HOBT N-hydroxybenzotriazole - OBzl benzyl ester - Boc tert-butoxycarbonyl - Z bebzyloxycarbonyl - EtOH ethanol - ECUM extracorporeal ultrafiltration method - FAB-MS fast atom bombardment spectrometry - HPLC high-performance liquid chromatography - TLC thin-layer chromatography - AcOH acetic acid - AP-M aminopeptidase-M - PTH phenylthiohydantoin