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

Two novel isoleucyl tRNA synthetase inhibitors, SE-203207 and SE-203208 hav e been isolated from a Streptomyces sp. and found to be structurally relate d to altemicidin. Structures of SE-203207 and SE-203208 have been deduced b y a combination of spectroscopic techniques, derivatisation, hydrolysis stu dies and found to be 4-(aminocarbonyl)-7-{[(2-amino-3 -methylpentanoyl)amin osulphonyl]acetamido}-2,4a,5,6,7,7a-hexahydro-6-hydroxy-2-methyl-1H-2-pyrin dine-7-carboxylic acid (1) and 4-(aminocarbonyl)-7-{[(2-amino-3-methyl pent anoyl)-aminosulphonyl]acetamido}-2,4a,5,6,7,7a-hexahydro-6-(2-amino-3-pheny lbutanoyl oxy)-2-methyl-1H-2-pyrindine-7-carboxylic acid (2), respectively.