Metabolic modeling of antibiotic and cytotoxic effects of the isoquinoline IQ-238 in S. aureus, S. epidermidis and human cells. Staphylococcus aureus

Isoquinolines (IQs) are natural substances with antibiotic potential. IQ-238 is a synthetic analog of the novel-type N,C-coupled naphtylisoquinoline (NIQ) alkaloid ancisheynine. Gene expression data, cytotoxicity measurements and metabolic modelling is combined to assess the effects of the N,C-coupled naphtylisoquinoline (NIQ) compound IQ-238 on Staphylococcus aureus and man as a potential lead for novel antibiotics. It possesses a high activity against staphylococci but has low cytotoxicity in human cell lines. Genome annotation identified missed enzymes (validated by PCR) in the primary (e.g. nucleotide) metabolism of staphylococci. Gene expression changed after cultivation with IQ-238. Metabolic modelling did yield the adaptations of all central enzymes, including those not affected by significant gene expression changes. The data show that IQ-238 interferes with the carbohydrate metabolism in staphylococci. The data suggest that IQ-238 is a promising lead for antibiotic therapy against S. aureus infections. Overall design: HG001 WT strain exposed to GB-AP-238 in rich medium