New alpha-amylase inhibitor, trestatins. I. Isolation, characterization and biological activities of trestatins A, B and C.

Trestatin complex which exhibited a potent inhibitory activity on various alpha-amylases has been isolated from the culture filtrate of Streptomyces dimorphogenes nov. sp. NR-320-OM7HB. Three major components, trestatins A, B and C, have been purified by adsorption and ion-exchange chromatography. Their spectral and chemical properties suggested that trestatins were novel basic oligosaccharide homologues each characterized by the possession of a trehalose moiety at the non-reducing end of the molecule.