SB-203207 and SB-203208, two novel isoleucyl tRNA synthetase inhibitors from a Streptomyces sp. II. Structure determination.

Two novel isoleucyl tRNA synthetase inhibitors, SB-203207 and SB-203208 have been isolated from a Streptomyces sp. and found to be structurally related to altemicidin. Structures of SB-203207 and SB-203208 have been deduced by a combination of spectroscopic techniques, derivatisation, hydrolysis studies and found to be 4-(aminocarbonyl)-7-[[(2-amino-3-methylpentanoyl)aminosul phonyl]acetamido]-2,4a,5,6,7,7a-hexahydro-6-hydroxy-2-methyl-1H-2- pyrindine-7-carboxylic acid (1) and 4-(aminocarbonyl)-7-[[(2-amino-3-methyl pentanoyl)-aminosulphonyl]acetamido]-2,4a,5,6,7,7a-hexahydro-6-(2- amino-3-phenylbutanoyl oxy)-2-methyl-1H-2-pyrindine-7-carboxylic acid (2), respectively.