D. Perlman

Microbial production of vitamin B12 antimetabolites: II. 2-Amino-4-keto-3-methylpentanoic acids from bacillus cereus 439

Abstract 2-Amino-4-keto-3-methylpentanoic acids were isolated as a diastereomeric mixture from Bacillus cereus 439 fermentations and found to be vitamin B 12 antimetabolites in a bioassay system based on the vitamin B 12 -requiring Escherichia coli (Davis 113-3). A similar diastereomeric mixture with bioactivity was synthesized by condensation of 2-bromo-3-butanone with sodio diethyl acetamidomalonate followed by hydrolysis with 6 N HCl and purification by ion-exchange chromatography. The growth inhibitory effects of the antimetabolite were reversed by vitamin B 12 , l -methionine, l -isoleucine, l -leucine, l -valine, and d -alanine.

Streptamine-Containing Antibioti Cs

Publisher Summary Streptomycin is clinically used for the treatment of tuberculosis, systemic infections by gram-negative bacteria, and bacterial infections of the urinary tract as therapeutic use described in the chapter. The usual dose is 0.5 to 1.0 g per day by intra muscular injection. The streptomycin hydrochloride was further purified by chromatography on acid-washed aluminum oxide in a ratio of 10 to 30 g of adsorbent to 1 g streptomycin hydrochloride concentrate. The columns were filled with the adsorbent and methanol, and the solvent was allowed to drain until a layer of solvent above the adsorbent was approximately 1 to 2 mm deep. The precipitate was removed by filtration and the filtrate was treated with 3g of activated carbon and filtered. The filtrate was diluted to 50 ml and then lyophilized yielding about 17. 2 g of purified streptomycin sulfate. The column was then back washed with water until the pH of the effluent liquid was about 10.5. The filtered broth obtained from a streptomycin-producing fermentation was adjusted to pH 7 and passed over the column at a rate, such that the broth was in contact with the resin for about 1 min.