The synthesis of (<i>Z</i>)-4-oxo-4-(arylamino)but-2-enoic acids derivatives and determination of their inhibition properties against human carbonic anhydrase I and II isoenzymes

<p>The synthesis of (<i>Z</i>)-4-oxo-4-(arylamino)but-2-enoic acid (<b>4</b>) derivatives containing structural characteristics that can be used for the synthesis of several active molecules, is presented. Some of the butenoic acid derivatives (<b>4a</b>, <b>4c</b>, <b>4e</b>, <b>4i</b>, <b>4j</b>, <b>4k</b>) are synthesized following literature procedures and at the end of the reaction. In addition, structures of all synthesized derivatives (<b>4a</b>–<b>4m</b>) were determined by ¹H-NMR, ¹³C-NMR and IR spectroscopy. Carbonic anhydrase is a metalloenzyme involved in many crucial physiologic processes as it catalyzes a simple but fundamental reaction, the reversible hydration of carbon dioxide to bicarbonate and protons. Significant results were obtained by evaluating the enzyme inhibitory activities of these derivatives against human carbonic anhydrase hCA I and II isoenzymes (hCA I and II). Butenoic acid derivatives (<b>4a</b>–<b>4m</b>) strongly inhibited hCA I and II with <i>K</i>_is in the low nanomolar range of 1.85 ± 0.58 to 5.04 ± 1.46 nM against hCA I and in the range of 2.01 ± 0.52 to 2.94 ± 1.31 nM against hCA II.</p

Synthesis and inhibitory properties of some carbamates on carbonic anhydrase and acetylcholine esterase

A series of carbamate derivatives were synthesized and their carbonic anhydrase I and II isoenzymes and acetylcholinesterase enzyme (AChE) inhibitory effects were investigated. All carbamates were synthesized from the corresponding carboxylic acids via the Curtius reactions of the acids with diphenyl phosphoryl azide followed by addition of benzyl alcohol. The carbamates were determined to be very good inhibitors against for AChE and hCA I, and II isoenzymes. AChE inhibition was determined in the range 0.209-0.291 nM. On the other hand, tacrine, which is used in the treatment of Alzheimer's disease possessed lower inhibition effect (Ki: 0.398 nM). Also, hCA I and II isoenzymes were effectively inhibited by the carbamates, with inhibition constants (Ki) in the range of 4.49-5.61 nM for hCA I, and 4.94-7.66 nM for hCA II, respectively. Acetazolamide, which was clinically used carbonic anhydrase (CA) inhibitor demonstrated Ki values of 281.33 nM for hCA I and 9.07 nM for hCA II. The results clearly showed that AChE and both CA isoenzymes were effectively inhibited by carbamates at the low nanomolar levels