Benzothiazepine compounds have a wide range of applications such as antibacterial, antidepressants, anticonvulsants, antihypertensives, antibiotics, antifungal, hypnotic, enzyme inhibitors, antitumor, anticancer and anti-HIV agents. In this study, the synthesis of novel tetralone-based benzothiazepine derivatives (1-16) and their in vitro antibacterial activity and human carbonic anhydrase isoenzymes I and II ( hCA I and II) inhibitory effects were investigated. Both isoenzymes were purified by sepharose-4B-L-tyrosine-sulfanilamide affinity chromatography from fresh human red blood cells. All compounds demonstrated the low nanomolar inhibitory effects on both isoenzymes using esterase activity. Benzothiazepine derivative 2 demonstrated the best hCA I inhibitory effect with Ki value of 18.19 nM. Also, benzothiazepine derivative 7 showed the best hCA II inhibitory effect with Ki value of 11.31 nM. On the other hand, acetazolamide clinically used as CA inhibitor, showed Ki value of 19.92 nM against hCA I and 33.60 nM against hCA II, respectively.