Novel Polyhydroquinoline-Hydrazide-Linked Schiff's Base Derivatives: Multistep Synthesis, Antimicrobial, and Calcium-Channel-Blocking Activities

Novel acyl hydrazide derivatives of polyhydroquinoline as potent anti-diabetic and anti-glycating agents: Synthesis, in vitro α-amylase, α-glucosidase inhibition and anti-glycating activity with molecular docking insights

In this study, eleven novel acyl hydrazides derivative of polyhydroquinoline were synthesized, characterized and screened for their in vitro anti-diabetic and anti-glycating activities. Seven compounds 2a, 2d, 2i, 2 h, 2j, 2f, and 2 g exhibited notable α-amylase inhibitory activity having IC50 values from 3.51 ± 2.13 to 11.92 ± 2.30 µM. Similarly, six compounds 2d, 2f, 2 h, 2i, 2j, and 2 g displayed potent α-glucosidase inhibitory activity compared to the standard acarbose. Moreover, eight derivatives 2d, 2 g, 2f, 2j, 2a, 2i, 2 g, and 2e showed excellent anti-glycating activity with IC50 values from 6.91 ± 2.66 to 15.80 ± 1.87 µM when compared them with the standard rutin (IC50 = 22.5 ± 0.90 µM). Molecular docking was carried out to predict the binding modes of all the compounds with α-amylase and α-glucosidase. The docking analysis revealed that most of the compounds established strong interactions with α-amylase and α-glucosidase. All compounds fitted well into the binding pockets of α-amylase and α-glucosidase. Among all compounds 2a and 2f were most potent based on docking score -8.2515 and -7.3949 against α-amylase and α-glucosidase respectively. These results hold promise for the development of novel candidates targeted at controlling postprandial glucose levels in individuals with diabetes.

Synthesis of 2,4-dihydroxyacetophenone derivatives as potent PDE-1 and -3 inhibitors: in vitro and in silico insights

Aim: Synthesis of novel bis-Schiff bases having potent inhibitory activity against phosphodiesterase (PDE-1 and -3) enzymes, potentially offering therapeutic implications for various conditions. Methods: Bis-Schiff bases were synthesized by refluxing 2,4-dihydroxyacetophenone with hydrazine hydrate, followed by treatment of substituted aldehydes with the resulting hydrazone to obtain the product compounds. After structural confirmation, the compounds were screened for their in vitro PDE-1 and -3 inhibitory activities. Results: The prepared compounds exhibited noteworthy inhibitory efficacy against PDE-1 and -3 enzymes by comparing with suramin standard. To clarify the binding interactions between the drugs, PDE-1 and -3 active sites, molecular docking studies were carried out. Conclusion: The potent compounds discovered in this study may be good candidates for drug development.

Synthesis, biochemical and computational evaluations of novel bis-acylhydrazones of 2,2'-(1,1'-biphenyl)-4,4'-diylbis(oxy))di(acetohydrazide) as dual cholinesterase inhibitors

A series of twenty-seven bis(acylhydrazones) were successfully synthesized with high yields through a multistep process, which entailed the esterification of hydroxyl groups, hydrazination with an excess of hydrazine hydrate, and subsequent reactions with various carbonyl moieties (aldehydes). In the final stage of synthesis, different chemical species including aromatic, heterocyclic, and aliphatic compounds were integrated into the framework. The resulting compounds were characterized using several spectroscopic techniques (1H NMR, 13C NMR, and mass spectrometry). Their anticholinesterase activities were assessed in vitro by examining their interactions with two cholinesterase enzymes: acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Among the synthesized hits, compounds 3, 5, 6, 9-12, and 14 exhibited good to moderate inhibition of AChE. Specifically, 10 (IC50 = 26.3 ± 0.4 μM) and 11 (IC50 = 28.4 ± 0.5 μM) showed good inhibitory activity against AChE, while 9, 12, 3, and 6 exhibited significant inhibition potential against AChE with IC50 values ranging from 35.2 ± 1.1 μM to 64.4 ± 0.3 μM. On the other hand, 5 (IC50 = 22.0 ± 1.1 μM) and 27 (IC50 = 31.3 ± 1.3 μM) displayed significant, and 19 (IC50 = 92.6 ± 0.4 μM) showed moderate inhibitory potential for BChE. Notably, 5 and 27 exhibited dual inhibition of AChE and BChE, with greater potency than the standard drug galantamine. The binding patterns of these molecules within the binding cavities of AChE and BChE were anticipated by molecular docking which showed good correlation with our in vitro findings. Further structural optimization of these molecules may yield more potent AChE and BChE inhibitors.

Novel hydrazone schiff's base derivatives of polyhydroquinoline: synthesis, in vitro prolyl oligopeptidase inhibitory activity and their Molecular docking study

This research work reports the synthesis of new derivatives of the hydrazone Schiff bases (1-17) based on polyhydroquinoline nucleus through multistep reactions. HR-ESIMS,1H- and 13C-NMR spectroscopy were used to structurally infer all of the synthesized compounds and lastly evaluated for prolyl oligopeptidase inhibitory activity. All the prepared products displayed good to excellent inhibitory activity when compared with standard z-prolyl-prolinal. Three derivatives 3, 15 and 14 showed excellent inhibition with IC50 values 3.21 ± 0.15 to 5.67 ± 0.18 µM, while the remaining 12 compounds showed significant activity. Docking studies indicated a good correlation with the biochemical potency of compounds estimated in the in-vitro test and showed the potency of compounds 3, 15 and 14. The MD simulation results confirmed the stability of the most potent inhibitors 3, 15 and 14 at 250 ns using the parameters RMSD, RMSF, Rg and number of hydrogen bonds. The RMSD values indicate the stability of the protein backbone in complex with the inhibitors over the simulation time. The RMSF values of the binding site residues indicate that the potent inhibitors contributed to stabilizing these regions of the protein, through formed stable interactions with the protein. The Rg. analysis assesses the overall size and compactness of the complexes. The maintenance of stable hydrogen bonds suggests the existence of favorable binding interactions. SASA analysis suggests that they maintained stable conformations without large-scale exposure to the solvent. These results indicate that the ligand-protein interactions are stable and could be exploited to design new drugs for disease treatment.Communicated by Ramaswamy H. Sarma.

Guanidine dicycloamine-based analogs: green chemistry synthesis, biological investigation, and molecular docking studies as promising antibacterial and antiglycation leads

Dicyandiamide (DCD) reacted with amino acids 1a-f to produce biguanides 2 and 4 and guanidine pyrazolones 3, 5, 6, 7, and 8, according to the reaction. DCD exhibited the following reactions: imidodicarbonimidicdiamide 9, diazocan-2-ylguanidine 10, methyl biguanidylthion 11, N-carbamothioylimidodicarbonimidicdiamide 12, 2-guanidinebenzoimidazole 13a, 2-guanidinylbenzoxazole 13b, and 2-guanidinylbenzothiazol 13c. These reactions were triggered by 6-amino caproic acid, thioacetamide, thiourea, o-aminophenol, o-aminothiophenol, and anthranilic acid, respectively. Compound 2 had the least antimicrobial activity, while compound 13c demonstrated the most antibacterial impact against all bacterial strains. Furthermore, in terms of antiglycation efficacy (AGEs), 12, 11, and 7 were the most effective AGE cross-linking inhibitors. Eight and ten, which showed a considerable inhibition on cross-linking AGEs, come next. Compounds 4 and 6 on the other hand have shown the least suppression of AGE production. The most promising antiglycation scaffolds 8, 11, and 12 in the Human serum albumin (HAS) active site were shown to be able to adopt crucial binding interactions with important amino acids based on the results of in silico molecular docking. The most promising antiglycation compounds 8, 11, and 12 were also shown to have better hydrophilicity, acceptable lipophilicity, gastrointestinal tract absorption (GIT), and blood-brain barrier penetration qualities when their physicochemical properties were examined using the egg-boiled method.

Polyhydroquinoline derivatives for diabetic management: synthesis, in vitro and in silico approaches

Background: Medication used to treat Type 2 diabetes by decreasing the absorption of carbohydrates in the intestine consists of α-glucosidase inhibitors. Polyhydroquinoline derivatives have attracted interest as excellent antidiabetic agents. Methods: Polyhydroquinoline derivatives (1-17) were synthesized and tested for in vitro α-glucosidase inhibitory activity. Results: All the synthesized compounds exhibited excellent to good inhibitory activity, having IC50 values from 1.23 ± 0.03 to 73.85 ± 0.61 μM, compared with the standard drug, acarbose. The binding mechanism of these derivatives with α-glucosidase was deduced by docking studies and indicated that a slight variation in the orientation of compounds, affects their binding capability. Conclusion: In order to find new antidiabetic drugs, this study has discovered prospective lead candidates.

Synthesis, molecular structure and urease inhibitory activity of novel bis-Schiff bases of benzyl phenyl ketone: A combined theoretical and experimental approach

Background

Urease belongs to the family of amid hydrolases with two nickel atoms in their core structure. On the basis of literature survey, this research work is mainly focused on the study of bis-Schiff base derivatives of benzyl phenyl ketone nucleus.

Objective

Synthesis of benzyl phenyl ketone based bis-Schiff bases in search of potent urease inhibitors.

Method

In the current work, bis-Schiff bases were synthesized through two steps reaction by reacting benzyl phenyl ketone with excess of hydrazine hydrate in ethanol solvent in the first step to get the desired hydrazone. In last, different substituted aromatic aldehydes were refluxed in catalytic amount of acetic acid with the desired hydrazone to obtain bis-Schiff base derivatives in tremendous yields. Using various spectroscopic techniques including FTIR, HR-ESI-MS, and ¹H NMR spectroscopy were used to clarify the structures of the created bis-Schiff base derivatives.

Results

The prepared compounds were finally screened for their in-vitro urease inhibition activity. All the synthesized derivatives (3-9) showed excellent to less inhibitory activity when compared with standard thiourea (IC₅₀ = 21.15 ± 0.32 µM). Compounds 3 (IC₅₀ = 22.21 ± 0.42 µM), 4 (IC₅₀ = 26.11 ± 0.22 µM) and 6 (IC₅₀ = 28.11 ± 0.22 µM) were found the most active urease inhibitors near to standard thiourea among the synthesized series. Similarly, compound 5 having IC₅₀ value of 34.32 ± 0.65 µM showed significant inhibitory activity against urease enzyme. Furthermore, three compounds 7, 8, and 9 exhibited less activity with IC₅₀ values of 45.91 ± 0.14, 47.91 ± 0.14, and 48.33 ± 0.72 µM respectively. DFT used to calculate frontier molecular orbitals including; HOMO and LUMO to indicate the charge transfer from molecule to biological transfer, and MEP map to indicate the chemically reactive zone suitable for drug action. The electron localization function (ELF), non-bonding orbitals, AIM charges are also calculated. The docking study contributed to the analysis of urease protein binding.