Wajid Rehman

Synthesis, spectral characterization and bio-analysis of some organotin(IV) complexes.

Five novel organotin(IV) derivatives have been synthesized by refluxing trimethyl, triethyl, tributyl, and triphenyl and tribenzyltin chloride with Schiff base derived from salicylaldehyde and adenine. These compounds were characterized by spectroscopic (IR, (1)H, (13)C, (119)Sn-NMR, (119m)Sn Mössbauer) techniques and elemental analysis. Based on these results, trigonal bipyramidal geometry is suggested. The synthesized compounds were also treated with various microorganisms and found to be active.

Isatin based Schiff bases as inhibitors of α-glucosidase: Synthesis, characterization, in vitro evaluation and molecular docking studies.

Isatin base Schiff bases (1-20) were synthesized, characterized by (1)H NMR and EI/MS and evaluated for α-glucosidase inhibitory potential. Out of these twenty (20) compounds only six analogs showed potent α-glucosidase inhibitory potential with IC50 value ranging in between 2.2±0.25 and 83.5±1.0μM when compared with the standard acarbose (IC50=840±1.73μM). Among the series compound 2 having IC50 value (18.3±0.56μM), 9 (83.5±1.0μM), 11 (3.3±0.25μM), 12 (2.2±0.25μM), 14 (11.8±0.15μM), and 20 (3.0±0.15μM) showed excellent inhibitory potential many fold better than the standard acarbose. The binding interactions of these active analogs were confirmed through molecular docking.

Triazinoindole analogs as potent inhibitors of α-glucosidase: synthesis, biological evaluation and molecular docking studies.

A new series of triazinoindole analogs 1-11 were synthesized, characterized by EI-MS and (1)H NMR, evaluated for α-glucosidase inhibitory potential. All eleven (11) analogs showed different range of α-glucosidase inhibitory potential with IC50 value ranging between 2.46±0.008 and 312.79±0.06 μM when compared with the standard acarbose (IC50, 38.25±0.12 μM). Among the series, compounds 1, 3, 4, 5, 7, 8, and 11 showed excellent inhibitory potential with IC50 values 2.46±0.008, 37.78±0.05, 28.91±0.0, 38.12±0.04, 37.43±0.03, 36.89±0.06 and 37.11±0.05 μM respectively. All other compounds also showed good enzyme inhibition. The binding modes of these analogs were confirmed through molecular docking.

Synthesis, characterization, antimicrobial and antitumor screening of some diorganotin(IV) complexes of 2-[(9H-Purin-6-ylimino)]-phenol.

A new series of diorganotin(IV) complexes of the type R(2)SnL(2) (R=Me, Et, Bu, Ph, Bz and L=2-[(9H-Purin-6-ylimino)]-phenol) have been synthesized, characterized by elemental analyses and their solid state configuration has been determined by various spectroscopic (IR, (1)H, (13)C, (119)Sn NMR, (119m)Sn Mössbauer) techniques. The results obtained on the basis of these techniques are in full concurrence with the proposed 2:1 stoichiometry. The title complexes have been screened against various microorganisms, fungi and human cell line KB, the results obtained showed that the bis(2-[(9H-Purin-6-ylimino)]-phenolate) diphenyltin(IV) complex exhibited excellent activity against all types of bacteria and fungi used, while bis(2-[(9H-Purin-6-ylimino)]-phenolate) diethyltin(IV) complex was found to have promising antitumor activity.

Comparative Study of Structure - Activity Relationship of Di and Triorganotin (IV) Complexes of Monomethyl Glutarate

A series of di and triorganotin(IV) complexes of monomethyl glutarate have been synthesized and characterized through 1H 13C 119Sn NMR, FT-IR and 119Sn Mossbauer spectroscopy. On the basis of these techniques, it is proposed that the ligand molecule is bound to the tin atom through the carbonyl oxygen. The data reveal that diorganotin(IV) complexes exhibit hexa-coordination with octahedral geometry, while triorganotin(IV) complexes have penta-coordination with trigonal bipyramidal geometry. Biological evaluation against various microorganisms indicate that diorganotin(IV) complexes are less active than the triorganotin(IV) complexes.

Synthesis and structure–activity relationship of thiobarbituric acid derivatives as potent inhibitors of urease

A series of thiobarbituric acid derivatives 1-27 were synthesized and evaluated for their urease inhibitory potential. Exciting results were obtained from the screening of these compounds 1-27. Compounds 5, 7, 8, 11, 16, 17, 22, 23 and 24 showed excellent urease inhibition with IC50 values 18.1 ± 0.52, 16.0 ± 0.45, 16.0 ± 0.22, 14.3 ± 0.27, 6.7 ± 0.27, 10.6 ± 0.17, 19.2 ± 0.29, 18.2 ± 0.76 and 1.61 ± 0.18 μM, respectively, much better than the standard urease inhibitor thiourea (IC₅₀=21 ± 0.11 μM). Compound 3, 4, 10, and 26 exhibited comparable activities to the standard with IC₅₀ values 21.4 ± 1.04 and 21.5 ± 0.61 μM, 22.8 ± 0.32, 25.2 ± 0.63, respectively. However the remaining compounds also showed prominent inhibitory potential The structure-activity relationship was established for these compounds. This study identified a novel class of urease inhibitors. The structures of all compounds were confirmed through spectroscopic techniques such as EI-MS and (1)H NMR.

Synthesis, characterization, and biological study of some biologically potent schiff base transition metal complexes

The synthesis and characterization of a Schiff base derived from aniline and salicylaldehyde and its Co(II), Mn(II), and Zn(II) complexes is reported; several physical tools, in particular, elemental analysis, infrared and NMR techniques were used to investigate the chemical structure of the reported complexes. The ligand is found to be bound to the metal atom through the oxygen atom of the hydroxyl group, which is also supported by spectroscopic techniques. The results obtained by FT-IR and NMR showed that the Schiff base-transition metal complexes have octa hedral geometry. Biological screening of the complexes reveals that the Schiff base-transition metal complexes show significant activity against all microorganisms.

Synthesis of 4-thiazolidinone analogs as potent in vitro anti-urease agents.

4-Thiazolidinone analogs 1-20 were synthesized, characterized by (1)H NMR and EI-MS and investigated for urease inhibitory activity. All twenty (20) analogs exhibited varied degree of urease inhibitory potential with IC50 values 1.73-69.65μM, if compared with standard thiourea having IC50 value of 21.25±0.15μM. Among the series, eight derivatives 3, 6, 8, 10, 15, 17, 19, and 20 showed outstanding urease inhibitory potential with IC50 values of 9.34±0.02, 14.62±0.03, 8.43±0.01, 7.3±0.04, 2.31±0.002, 5.75±0.003, 8.81±0.005, and 1.73±0.001μM, respectively, which is better than the standard thiourea. The remaining analogs showed good to excellent urease inhibition. The binding interactions of these compounds were confirmed through molecular docking studies.

Synthesis and in vitro acetylcholinesterase and butyrylcholinesterase inhibitory potential of hydrazide based Schiff bases

To discover multifunctional agents for the treatment of Alzheimers disease, a series of hydrazide based Schiff bases were designed and synthesized based on multitarget-directed strategy. We have synthesized twenty-eight analogs of hydrazide based Schiff bases, characterized by various spectroscopic techniques and evaluated in vitro for acetylcholinesterase and butyrylcholinesterase inhibition. All compounds showed varied degree of acetylcholinesterase and butyrylcholinesterase inhibition when compared with standard Eserine. Among the series, compounds 10, 3 and 24 having IC50 values 4.12±0.01, 8.12±0.01 and 8.41±0.06μM respectively showed potent acetylcholinesterase inhibition when compared with Eserine (IC50=0.85±0.0001μM). Three compounds 13, 24 and 3 having IC50 values 6.51±0.01, 9.22±0.07 and 37.82±0.14μM respectively showed potent butyrylcholinesterase inhibition by comparing with eserine (IC50=0.04±0.0001μM). The remaining compounds also exhibited moderate to weak inhibitory potential. Structure activity relationship has been established. Through molecular docking studies the binding interaction was confirmed.

Adsorption of heavy metal ions in ternary systems onto Fe(OH)3

The adsorption behavior of amorphous Fe(OH)3 has been studied in multicomponent metal system. The metal ions uptake in the ternary system is lower than in the single system, suggesting that certain sites on the surface of the solid are blocked due to competition. The selectivity trend in the ternary system is observed to be Ni2+>Zn2+>Cd2+ which is, however, lost with increase in the temperature of the aqueous solution. Further, the observed selectivity trend is neither related to electronegativity of the metal ions nor to the pH of the hydrolysis, but has been found dependent on charge to radius ratio. The metal ions adsorption is found to increase with pH, while the converse is true with the rise in temperature. The uptake of metal ions data has been interpreted in terms of stoichiometry, binding constants and adsorption capacities. The negative values of ΔG show that uptake of metal ions is favored at lower temperatures, indicating that the adsorption mechanism essentially remains ion exchange in nature.