Synthesis, Carbonic Anhydrase II/IX/XII Inhibition, DFT, and Molecular Docking Studies of Hydrazide-Sulfonamide Hybrids of 4-Methylsalicyl- and Acyl-Substituted Hydrazide.

Carbonic anhydrases (CAs and EC 4.2.1.1) are the Zn2+ containing enzymes which catalyze the reversible hydration of CO2 to carbonate and proton. If they are not functioning properly, it would lead towards many diseases including tumor. Synthesis of hydrazide-sulfonamide hybrids (19-36) was carried out by the reaction of aryl (10-11) and acyl (12-13) hydrazides with substituted sulfonyl chloride (14-18). Final product formation was confirmed by FT-IR, NMR, and EI-MS. Density functional theory (DFT) calculations were performed on all the synthesized compounds to get the ground-state geometries and compute NMR properties. NMR computations were in excellent agreement with the experimental NMR data. All the synthesized hydrazide-sulfonamide hybrids were in vitro evaluated against CA II, CA IX, and CA XII isozymes for their carbonic anhydrase inhibition activities. Among the entire series, only compounds 22, 32, and 36 were highly selective inhibitors of hCA IX and did not inhibit hCA XII. To investigate the binding affinity of these compounds, molecular docking studies of compounds 32 and 36 were carried out against both hCA IX and hCA XII. By using BioSolveIT's SeeSAR software, further studies to provide visual clues to binding affinity indicate that the structural elements that are responsible for this were also studied. The binding of these compounds with hCA IX was highly favorable (as expected) and in agreement with the experimental data.

Synthesis, in-vitro, in-vivo anti-inflammatory activities and molecular docking studies of acyl and salicylic acid hydrazide derivatives.

Over the course of time several drugs have been synthesized and are available in market for the treatment of inflammation. However, they were unable to cure effectively and associated with side effects. To effectively deal with such diseases, heterocycles and their derivatives have gained their special position. For this reason 1,3,4-oxadiazole (15-16), 1,2,4-triazole (17-18), Schiff base (19-24) and 3,5-disubstituted pyrazole (25) derivatives were synthesized starting from salicylic acid and acyl acid hydrazides (12-14) as COX-1 and COX-2 inhibitors. In vivo anti-inflammatory activities were also tested by carrageenan-induced mice paw edema against albino mice of any sex. Structures of all the synthesized compounds were confirmed by FT-IR and 1H NMR analysis. Schiff base derivative of 4-amiontirazole (24) with IC50 value of 1.76 ± 0.05 (COX-2) and 117.8 ± 2.59 emerged as potent COX-2 inhibitor. Furthermore, we also performed in-vivo anti-inflammatory investigations by using carrageenan induced paw edema test. From in-vivo anti-inflammatory activities, it was found that after 1 h the maximum percentage inhibition 15.8% was observed by compound 14 which is comparable with that of the standard drug followed by the compound 18 with percentage inhibition of 10.5%. After 3 h, the maximum percentage inhibition was observed by compound 18 with 22.2% and compound 14 with 16.7%. After 5 h the maximum percentage inhibition was observed by compound 18 with 29.4% followed by compound 16 with 23.5%. We further explore the mechanism of the inhibition by using docking simulations. Docking studies revealed that the selective COX-2 inhibitors established interactions with additional COX-2 enzyme pocket residues.