Bacterial resistance to antibiotics has become one of the most challenging problems of infectious disease treatment. Ten new derivatives of benzenesulphonamide bearing carboxamide functionality were synthesized and investigated for their in vivo anti-inflammatory, in vitro anti-microbial and anti-oxidant activities. The base promoted reactions of the appropriate amino acids with substituted benzenesulphonyl chlorides gave the benzene sulphonamides (3a-j) in excellent yields. Palladium mediated amidation of the benzenesulphonamides (3a-j) and butylamine gave the new carboxamides (4a-j) in excellent yield. Compounds 4a and 4c inhibited carrageenan induced rat-paw edema at 94.69, 89.66, and 87.83% each at 1, 2, and 3 h, respectively. In the antimicrobial activity, compound 4d (MIC 6.72 mg/mL) was most potent against E. coli, compound 4h (MIC 6.63 mg/mL) was the most active against S. aureus, compound 4a (MIC 6.67 and 6.45 mg/mL) was most active against P. aeruginosa and S. typhi, respectively, compound 4f (MIC 6.63 mg/mL) was the most active against B. subtilis, compounds 4e and 4h (MIC 6.63 mg/mL) each were the most active against C. albicans, while compound 4e (MIC 6.28 mg/mL) was most active against A. niger. Only compound 4e (IC₅₀ 0.3287 mg/mL) had comparable activity with Vitamin C (IC₅₀ 0.2090 mg/mL).

A tripodal Schiff base ligand, 2,4,6-Tris(4-carboxybenzimino)-1,3,5-triazine (MT) and its trinuclear Dy(III), Er(III), and Gd(III) complexes were synthesized. These were characterized using UV-visible, IR, ¹H, and ¹³C NMR spectroscopies, elemental analysis, and molar conductivity measurements. The spectral studies indicate that the ligand is hexadentate and coordinates to the Ln(III) ions through the oxygen atoms of the carboxylic group. The trinuclear complexes were characterized as being bridged by carboxylate anions to the Dy(III), Er(III), and Gd(III) salen centers and displaying a coordination number of six. Biological studies revealed that MT is more active against the test micro-organisms relative to the trinuclear complexes. Acute toxicity studies revealed that MT is safe and has a wide range of effective doses (ED₅₀). In vivo antimalarial studies indicate that MT could serve as an effective antimalarial agent since it has parasitemia inhibition of 84.02% at 50 mg/kg and 65.81% at 25 mg/kg, close to the value (87.22%) of the standard drug—Artesunate. Molecular docking simulation studies on the compounds against SARS-CoV-2 (6Y84) and E. coli DNA gyrase (5MMN) revealed effective binding interactions through multiple bonding modes. The binding energy calculated for Er(III)MT-6Y84 and Er(III)MT-5MMN complexes showed active molecules with the ability to inhibit SARS-CoV-2 and E. coli DNA gyrase.

: Carbohydrazides and their Schiff bases are important classes of heterocycles that are not only employed in the area of organic chemistry but also have tremendous applications in physical and inorganic chemistry. A series of potentially bioactive compounds containing carbohydrazide functionality and their hydrazone derivatives have been synthesized and screened for antibacterial, anticancer, antifungal and anti-inflammatory, etc. This brief review discloses some synthetic routes to so many reported carbohydrazides, their Schiff bases, their biological activities, and their structure-activity relationship.

Synthesis of sulfonamide through an indirect method that avoids contamination of the product with no need for purification has been carried out using the indirect process. Here, we report the synthesis of a novel sulfonamide compound, ({4-nitrophenyl}sulfonyl)tryptophan (DNSPA) from 4-nitrobenzenesulphonylchloride and L-tryptophan precursors. The slow evaporation method was used to form single crystals of the named compound from methanolic solution. The compound was characterized by X-ray crystallographic analysis and spectroscopic methods (NMR, IR, mass spectrometry, and UV-vis). The sulfonamide N-H NMR signal at 8.07–8.09 ppm and S-N stretching vibration at 931 cm⁻¹ indicate the formation of the target compound. The compound crystallized in the monoclinic crystal system and P2₁ space group with four molecules of the compound in the asymmetric unit. Molecular aggregation in the crystal structure revealed a 12-molecule aggregate synthon sustained by O-H⋯O hydrogen bonds and stabilised by N-H⋯O intermolecular contacts. Experimental studies were complemented by DFT calculations at the B3LYP/6-311++G(d,p) level of theory. The computed structural and spectroscopic data are in good agreement with those obtained experimentally. The energies of interactions between the units making up the molecule were calculated. Molecular docking studies showed that DNSPA has a binding energy of −6.37 kcal/mol for E. coli DNA gyrase (5MMN) and −6.35 kcal/mol for COVID-19 main protease (6LU7).

Five new sulfonamide deriatives bearing dipeptide moieties (4a-e) were synthesized and assessed for their inhibitory activity against acetylcholinesterase and butyrylcholinesterase. First, the condensation reaction of benzenesulfonyl chlorides (1a-c) and various amino acids (2a-d) led to the formation of various amino acid derivatives of sulfonamide (3a-e), which were further treated with amino acids (2a-d), using phenylboronic acid as a catalyst, to obtain the sulfonamide containing dipeptide moiety (4a-e) . The compounds were characterized using ¹ H and ¹³ C NMR spectra. The acetylcholinesterase and butyrylcholinesterase inhibitory studies showed that compounds 4a, 4b, and 4c had high inhibition efficiency at both high and low concentrations of acetylcholinesterase, while compounds 4d and 4e could only inhibit acetylcholinesterase at low concentrations. It also showed that compounds 4a, 4b, 4c, and 4e had high inhibition efficiency at both high and low concentrations of butyrylcholinesterase, while compound 4d could only inhibit butyrylcholinesterase at low concentrations. Their in‐silico physiochemical properties, bioactivity, and drug‐likeness were predicted, while the IC ₅₀ values were reported as mean ± standard deviation from triplicate measurements and compared to the standard drug donepezil. Compound 4a displayed the best activity with IC ₅₀ of 0.89 and 2.74 μM against acetylcholinesterase and butyrylcholinesterase, respectively.