Design and synthesis of some new benzoylthioureido benzenesulfonamide derivatives and their analogues as carbonic anhydrase inhibitors

The present investigation reports the design and synthesis of three series of benzoylthioureido derivatives bearing either benzenesulfonamide 7a–f, benzoic acid 8a–f or ethylbenzoate 9a–f moieties. The synthesised compounds were screened for their carbonic anhydrase inhibitory activity (CAI) against four isoforms hCA I, II, IX, and XII. Compounds 7a, 7b, 7c, and 7f exhibited a potent inhibitory activity towards hCAI (K_is = 58.20, 56.30, 33.00, and 43.00 nM), respectively compared to acetazolamide (AAZ) and SLC-0111 (K_is = 250.00 and 5080.00 nM). Compounds 7a, 7b, 7c, 7e, and 7f elicited selectivity over h CA II (K_is = 2.50, 2.10, 56.60,39.60 and 39.00 nM) respectively, relative to AAZ and SLC-0111(K_is = 12.10 and 960.00 nM). Also, compounds 7c, 7f, and 9e displayed selectivity against the tumour-associated isoform hCA IX (K_is = 31.20, 30.00 and 29.00 nM) respectively, compared to AAZ and SLC-0111 (K_is = 25.70 and 45.00 nM). Additionally, compounds 8a and 8f revealed a moderate to superior selectivity towards hCAXII (K_is = 17.00 and 11.00 nM) relative to AAZ and SLC-0111(K_is = 5.70 and 45.00 nM). Molecular docking and ADME prediction studies were performed on the most active compounds to shed light on their interaction with the hot spots of the active site of CA isoforms, in addition to prediction of their pharmacokinetic and physicochemical properties.

Determination of the Ionization Constants of Some Benzoyl Thiourea Derivatives in Dioxane-Water Mixture

The stoichiometric ionization constants ofN,N-dialkyl-N′-(4-substituted benzoyl) thiourea (Substitutes: H, Cl, and Br; alkyl groups: ethyl,n-propyl,n-butyl, and phenyl) derivatives have been determined potentiometrically in dioxane-water (v:v, 50:50) mixture at ionic strength of 0.1 M and25.0±0.1°C. The ionization constants were calculated with the BEST computer program and the formation curves using the data obtained from the potentiometric titrations. The effects of substituents and alkyl groups on the ionization constants of the benzoyl thiourea derivatives have been investigated. A comparison of the basicities of ethyl,n-propyl, andn-butyl thiourea derivatives(−C2H5<−C3H7<−C4H9)shows that then-butyl group is a more powerful electron-releasing group than the other groups in 50% dioxane-50% water mixture (v:v). So, the acidity of benzoyl thiourea derivative compounds decreases, while the length of alkyl chain increases. The orders ofpKavalues for all thiourea derivatives are as expected in the light of steric, resonance and inductive effects of substituents. Furthermore, when the basicities of halogen derivatives of the same substitution pattern are compared, orders obtained (4-Br<4-Cl<4-H) can be explained by considering the total electronic substituent effect (electron-withdrawing and electron-donating effects) except the 4-Br_Ph derivative.

Synthesis and Characterization of Novel Thiourea Derivatives and Their Nickel and Copper Complexes

New benzoyl thiourea derivatives and their nickel and copper complexes were synthesized. The structure of the synthesized compounds were confirmed by elemental analysis, FT-IR, and1H NMR techniques. Four of the synthesized compounds are analyzed by X-ray single crystal diffraction technique. WhereasN,N-dimethyl-N′-(4-fluorobenzoyl)thiourea,N,N-diethyl-N′-(4-fluorobenzoyl)thiourea, andN,N-di-n-butyl-N′-(4-fluorobenzoyl) thiourea crystallize in the monoclinic system,bis(N,N-di-n-propyl-N′-(4-fluorobenzoyl)thioureato) nickel(II) complex crystallizes in the triclinic system. These ligand molecules form dimers through strong intermolecular hydrogen bonds such as N–H⋯S, C–H⋯O, and N–H⋯O. Moreover, there are different types of intramolecular interactions in the crystal structures.Bis(N,N-dimethyl-N′-(4-fluorobenzoyl)thioureato) nickel(II) complex has a nearly square-planar coordination. The distance of nickel atom from the best plane through the coordination sphere is 0.029 Å.