No abstract

No abstract

The structure of the {:I-galactosidase inhibitor, galactostatin, isolated from Streptomyces Iydicus PA-5726 was determined to be 5-amino-5-deoxygalactopyranose, in which the ring oxygen of galactose has been replaced by nitrogen. For this study, two derivatives of galactostatin were prepared by oxidation and reduction, respectively. The oxidation product of galactostatin was 5amino-5-deoxygalactonic-b-Iactam (galactostatin-Iactam) and the reduction product was 5-amino-1,5-dideoxygalactopyranose (I-deoxygalactostatin).

No abstract

From the hydrolysate of siomycin A, an antibiotic from Streptomyces sioyaensis, L-threonine, L-alanine, L-valine, r>~cysteine and three thiazole-4carboxylic acid derivatives were isolated. These thiazoles were identified as thiostreptine, 2-aminomethylthiazole-4-carboxylic acid and 2-(l-amino acetonyl) thiazole-4-carboxylic acid. A 4-(<#-hydroxyethyl)-8-hydroxyquinaldic acid, and two unidentified C10-and C12-compounds were also isolated in the hydrolysate. The formation of pyruvic acid (2 moles), a-amino-w-butyric acid (less than 1 mole), propionic acid (2~3 moles) and acetaldehyde (1 mole) by the action of acid or alkali on siomycin A was demonstrated. Siomycins A, B and C, sulfur-containing peptide antibiotics, have been isolated from cultures of Streptomyces sioyaensis and siomycin preparations1*^. Characterization of the three siomycins has been described previously2). Among these antibiotics,