This technology includes compositions useful as inhibitors of acetyltransferase Eis, whose upregulation causes kanamycin (KAN) resistance of tuberculosis (TB) infections, and therefore can be developed and utilized as a treatment for TB. In particular, the compositions are sulfonamide-based and sulfonyl isothiazole-based small molecules. Drug adjuvants in TB represent a conceptually novel approach to combatting a serious global epidemic of drug-resistant TB. This approach is an alternative to developing a new antibiotic, because the adjuvant is targeting a non-essential enzyme and is meant to function only in combination with an already established anti-TB therapeutic, KAN. A KAN adjuvant is especially important, because KAN is used as a drug of last resort in treating drug-resistant TB.