Investigation of inhibitory properties of some hydrazone compounds on hCA I, hCA II and AChE enzymes

The synthesis of novel unnatural amino acid by intramolecular aza-Michael addition reaction as multitarget enzyme inhibitors

Synthesis of novel unnatural amino acids (UAAs) from 4-oxo-4-phenylbut-2-enoic acid derivatives with intramolecular aza-Michael addition reaction in the presence of chlorosulfonyl isocyanate (CSI) was reported in soft conditions without any metal catalyst. Acids and base as a catalyst, and solvents effects were investigated for the synthesis of novel UAAs. This novel method provides inexpensive, practicable, and efficient approach to generate UAAs. The use of UAAs has attracted great interest in the development of therapeutic agents and drug discovery to improve their properties. In this context, in addition to the synthesis of new UAAs, their inhibition effects on important metabolic enzymes of acetylcholinesterase (AChE) and carbonic anhydrases I and II (hCA I and II) enzymes were investigated. The compound 2g showed the best inhibition for CA I and AChE enzymes, while compound 2i exhibited the best inhibition profile against CA II isoenzyme. The inhibition values of these compounds were found as 1.85 ± 0.64 for AChE, 0.53 ± 0.07 for hCA I, 0.44 ± 0.15 µM for hCA II, respectively, and they showed a stronger inhibitory property than acetazolamide (standard inhibitor for hCA I and II) and tacrine (standard inhibitor for AChE) molecules. The activity of the studied molecule against different proteins that are hCA I (PDB ID: 2CAB), hCA II (PDB ID: 5AML), and AChE (PDB ID: 1OCE) was examined. Finally, the drug properties of the studied molecule were examined by performing absorption, distribution, metabolism, excretion, and toxicity analysis.

Synthesis and biological studies of pyrimidine derivatives targeting metabolic enzymes

Novel synthesized pyrimidine derivatives were investigated against carbonic anhydrase isoenzymes I and II (hCA I and II), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-glycosidase, and aldose reductase (AR) enzymes associated with some common diseases such as epilepsy, glaucoma, Alzheimer's disease, diabetes, and neuropathy. When the results were examined, novel synthesized pyrimidine derivatives were found to have effective inhibition abilities toward the metabolic enzymes. IC50 values and Ki values were calculated for each pyrimidine derivative and compared to positive controls. The synthesized novel pyrimidine derivatives exhibited Ki values in the range of 39.16 ± 7.70-144.62 ± 26.98 nM against hCA I, 18.21 ± 3.66-136.35 ± 21.48 nM toward hCA II, which is associated with different pathological and physiological processes, 33.15 ± 4.85-52.98 ± 19.86 nM on AChE, and 31.96 ± 8.24-69.57 ± 21.27 nM on BChE. Also, Ki values were determined in the range of 17.37 ± 1.11-253.88 ± 39.91 nM against α-glycosidase and 648.82 ± 53.74-1902.58 ± 98.90 nM toward AR enzymes. Within the scope of the study, the inhibition types of the novel synthesized pyrimidine derivatives were evaluated.

Rationale design of novel substituted 1,3,5-triazine candidates as dual IDH1(R132H)/ IDH2(R140Q) inhibitors with high selectivity against acute myeloid leukemia: In vitro and in vivo preclinical investigations

In this study, novel substituted 1,3,5-triazine candidates (4a-d, 5a-j, and 6a-d) were designed as second-generation small molecules to act as dual IDH1 and IDH2 inhibitors according to the pharmacophoric features of both vorasidenib and enasidenib. Compounds 6a and 6b for leukemia cell lines showed from low to sub-micromolar GI50. Moreover, compounds 4c, 5f, and 6b described the frontier antitumor activity against THP1 and Kasumi Leukemia cancer cells with IC50 values of (10 and 12), (10.5 and 7), and (6.2 and 5.9) µg/mL, which were superior to those of cisplatin (25 and 28) µg/mL, respectively. Interestingly, compounds 4c, 6b, and 6d represented the best dual IDH1(R132H)/IDH2(R140Q) inhibitory potentials with IC50 values of (0.72 and 1.22), (0.12 and 0.93), and (0.50 and 1.28) µg/mL, respectively, compared to vorasidenib (0.02 and 0.08) µg/mL and enasidenib (0.33 and 1.80) µg/mL. Furthermore, the most active candidate (6b) has very promising inhibitory potentials towards HIF-1α, VEGF, and SDH, besides, a marked increase of ROS was observed as well. Besides, compound 6b induced the upregulation of P53, BAX, Caspases 3, 6, 8, and 9 proteins by 3.70, 1.99, 2.06, 1.73, 1.75, and 1.85-fold changes, respectively, and the downregulation for the BCL-2 protein by 0.55-fold change compared to the control. Besides, the in vivo behavior of compound 6b as an antitumor agent was evaluated in female mice bearing solid Ehrlich carcinoma tumors. Notably, compound 6b administration resulted in a prominent decrease in the weight and volume of the tumors, accompanied by improvements in biochemical, hematological, and histological parameters.

New sulfonamide-based glycosides incorporated 1,2,3-triazole as cytotoxic agents through VEGFR-2 and carbonic anhydrase inhibitory activity

New sulfonamide-triazole-glycoside hybrids derivatives were designed, synthesised, and investigated for anticancer efficacy. The target glycosides' cytotoxic activity was studied with a panel of human cancer cell lines. Sulfonamide-based derivatives, 4, 7 and 9 exhibited promising activity against HepG-2 and MCF-7 (IC50 = 8.39-16.90 μM against HepG-2 and 19.57-21.15 μM against MCF-7) comparing with doxorubicin (IC50 = 13.76 ± 0.45, 17.44 ± 0.46 μM against HepG-2 and MCF-7, rescpectively). To detect the probable action mechanism, the inhibitory activity of these targets was studied against VEGFR-2, carbonic anhydrase isoforms hCA IX and hCA XII. Compoumds 7 and 9 gave favorable potency (IC50 = 1.33, 0.38 μM against VEGFR-2, 66, 40 nM against hCA IX and 7.6, 3.2 nM against hCA XII, respectively), comparing with sorafenib and SLC-0111 (IC50 = 0.43 μM, 53 and 4.8 nM, respectively). Moreover, the docking simulation was assessed to supply better rationalization and gain insight into the binding affinity between the promising derivatives and their targeted enzymes that was used for further modification in the anticancer field.

Benzimidazole-derived carbohydrazones as dual monoamine oxidases and acetylcholinesterase inhibitors: design, synthesis, and evaluation

A series of novel benzimidazole-derived carbohydrazones was designed, synthesized and evaluated for their dual inhibition potential against monoamine oxidases (MAOs) and acetylcholinesterase (AChE) using multitarget-directed ligand approach (MTDL). The investigated compounds have exhibited moderate to excellent in vitro MAOs/AChE inhibitory activity at micromolar to nanomolar concentrations. Compound 12, 2-(1H-Benzo[d]imidazol-1-yl)-N'-[1-(4-hydroxyphenyl) ethylidene]acetohydrazide has emerged as a lead dual MAO-AChE inhibitor by exhibiting superior multi-target activity profile against MAO-A (IC50 = 0.067 ± 0.018 µM), MAO-B (IC50 = 0.029 ± 0.005 µM) and AChE (IC50 = 1.37 ± 0.026 µM). SAR studies suggest that the site A (hydrophobic ring) and site C (semicarbazone linker) modifications attempted on the semicarbazone-based MTDL resulted in a significant enhancement in the MAO-A/B inhibitory potential and a drastic decrease in the AChE inhibitory activity. Further, molecular docking and dynamics simulation experiments disclosed the possible molecular interactions of inhibitors inside the active site of respective enzymes. Also, computational prediction of drug-likeness and ADME parameters of test compounds revealed their drug-like characteristics.Communicated by Ramaswamy H. Sarma.

Biological and computational evaluation of novel benzofuranyl derivatives as acetylcholinesterase and butyrylcholinesterase inhibitors

Aim: A highly efficient one-step method has been developed for the synthesis of benzofuranyl derivatives from 2-benzoylcyclohexane-1-carboxylic acid derivatives using chlorosulfonyl isocyanate. This novel method provides a practical, cost-effective and efficient approach. Materials & methods: The inhibitory effects of benzofuranyl derivatives on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes were investigated. Ki values were determined to range from 0.009 to 0.61 μM for AChE and 0.28 to 1.60 μM for BChE. Molecular docking analysis provided insights into the interaction modes and binding patterns of these compounds with AChE and BChE. Conclusion: Kinetic findings of our study suggest that some of our compounds exhibited more effective low micromolar inhibition compared with the reference, and these derivatives could be used to design more powerful agents.

4-Hydroxybenzoic Acid-Based Hydrazide-Hydrazones as Potent Growth Inhibition Agents of Laccase-Producing Phytopathogenic Fungi That Are Useful in the Protection of Oilseed Crops

The research on new compounds against plant pathogens is still socially and economically important. It results from the increasing resistance of pests to plant protection products and the need to maintain high yields of crops, particularly oilseed crops used to manufacture edible and industrial oils and biofuels. We tested thirty-five semi-synthetic hydrazide-hydrazones with aromatic fragments of natural origin against phytopathogenic laccase-producing fungi such as Botrytis cinerea, Sclerotinia sclerotiorum, and Cerrena unicolor. Among the investigated molecules previously identified as potent laccase inhibitors were also strong antifungal agents against the fungal species tested. The highest antifungal activity showed derivatives of 4-hydroxybenzoic acid and salicylic aldehydes with 3-tert-butyl, phenyl, or isopropyl substituents. S. sclerotiorum appeared to be the most susceptible to the tested compounds, with the lowest IC50 values between 0.5 and 1.8 µg/mL. We applied two variants of phytotoxicity tests for representative crop seeds and selected hydrazide-hydrazones. Most tested molecules show no or low phytotoxic effect for flax and sunflower seeds. Moreover, a positive impact on seed germination infected with fungi was observed. With the potential for application, the cytotoxicity of the hydrazide-hydrazones of choice toward MCF-10A and BALB/3T3 cell lines was lower than that of the azoxystrobin fungicide tested.

3D-QSAR-based pharmacophore modelling of quinazoline derivatives for the identification of acetylcholinesterase inhibitors through virtual screening, molecular docking, molecular dynamics and DFT studies

Alzheimer's disease (AD) is a progressive neurological disorder responsible for the cognitive dysfunction and cognitive impairment in the patients. Acetylcholinesterase inhibitors (AChEIs) are used to treat AD however, these only provided symptomatic relief and more efficient drug molecules are desired for the effective treatment of the disease. In this article, ligand-based drug-designing strategy was used to develop and validate a field-based 3D-QSAR pharmacophore model on quinazoline-based AChEIs reported in the literature. The validated pharmacophore model (AAAHR_1) was used as a prefilter to screen an ASINEX database via virtual screening workflow (VSW). The hits generated were subjected to MM-GBSA to identify potential AChEIs and top three scoring molecules (BAS 05264565, LEG 12727144 and SYN 22339886) were evaluated for thermodynamic stability at the target site using molecular dynamic simulations. Additionally, DFT study was performed to predict the reactivity of lead molecules towards acetylcholinesterase (AChE). Thus, by utilising various computational tools, three molecules were identified as potent AChEIs that can be developed as potential drug candidates for the treatment of AD.Communicated by Ramaswamy H. Sarma.

In vitro and in vivo Biological Evaluation of Newly Tacrine-Selegiline Hybrids as Multi-Target Inhibitors of Cholinesterases and Monoamine Oxidases for Alzheimer's Disease

Purpose

Alzheimer's disease (AD) is the most common neurodegenerative disease, and its multifactorial nature increases the difficulty of medical research. To explore an effective treatment for AD, a series of novel tacrine-selegiline hybrids with ChEs and MAOs inhibitory activities were designed and synthesized as multifunctional drugs.

Methods

All designed compounds were evaluated in vitro for their inhibition of cholinesterases (AChE/BuChE) and monoamine oxidases (MAO-A/B) along with their blood-brain barrier permeability. Then, further biological activities of the optimizing compound 7d were determined, including molecular model analysis, in vitro cytotoxicity, acute toxicity studies in vivo, and pharmacokinetic and pharmacodynamic property studies in vivo.

Results

Most synthesized compounds demonstrated potent inhibitory activity against ChEs/MAOs. Particularly, compound 7d exhibited good and well-balanced activity against ChEs (hAChE: IC50 = 1.57 μM, hBuChE: IC50 = 0.43 μM) and MAOs (hMAO-A: IC50 = 2.30 μM, hMAO-B: IC50 = 4.75 μM). Molecular modeling analysis demonstrated that 7d could interact simultaneously with both the catalytic active site (CAS) and peripheral anionic site (PAS) of AChE in a mixed-type manner and also exhibits binding affinity towards BuChE and MAO-B. Additionally, 7d displayed excellent permeability of the blood-brain barrier, and under the experimental conditions, it elicited low or no toxicity toward PC12 and BV-2 cells. Furthermore, 7d was not acutely toxic in mice at doses up to 2500 mg/kg and could improve the cognitive function of mice with scopolamine-induced memory impairment. Lastly, 7d possessed well pharmacokinetic characteristics.

Conclusion

In light of these results, it is clear that 7d could potentially serve as a promising multi-functional drug for the treatment of AD.

The synthesis, carbonic anhydrase and acetylcholinesterase inhibition effects of sulfonyl chloride moiety containing oxazolidinones using an intramolecular aza-Michael addition

Oxazolidinones are used as various potent antibiotics, in organisms it acts as a protein synthesis inhibitor, focusing on an initial stage that encompasses the tRNA binding process. Novel intramolecular aza-Michael reactions devoid of metal catalysts have been introduced in an oxazolidone synthesis pathway, different from α,β-unsaturated ketones. Oxazolidinone derivatives were tested against acetylcholinesterase (AChE), carbonic anhydrase I and II (hCA I and hCA II) enzymes. All the synthesized compounds had potent inhibition effects with Ki values in the range of 13.57 ± 0.98 - 53.60 ± 6.81 µM against hCA I and 9.96 ± 1.02 - 46.35 ± 3.83 µM against hCA II in comparison to the acetazolamide (AZA) (Ki = 50.46 ± 6.17 µM for hCA I) and for hCA II (Ki = 41.31 ± 5.05 µM). Also, most of the compounds demonstrated potent inhibition ability towards AChE enzyme with Ki values 78.67-231.75 nM and compared to tacrine (TAC) as standard clinical inhibitor (Ki = 142.48 nM). Furthermore, ADMET analysis and molecular docking were calculated using the AChE, hCA I and hCA II enzyme proteins to correlate the data with the experimental data. In this work, recent applications of a stereoselective aza-Michael reaction as an efficient tool for of nitrogen-containing heterocyclic scaffolds and their useful to pharmacology analogs are reviewed and summarized.Communicated by Ramaswamy H. Sarma.

Acetylphenyl-substituted imidazolium salts: synthesis, characterization, in silico studies and inhibitory properties against some metabolic enzymes

Herein, we present how to synthesize thirteen new 1-(4-acetylphenyl)-3-alkylimidazolium salts by reacting 4-(1-H-imidazol-1-yl)acetophenone with a variety of benzyl halides that contain either electron-donating or electron-withdrawing groups. The structures of the new imidazolium salts were conformed using different spectroscopic methods (1H NMR, 13C NMR, 19F NMR, and FTIR) and elemental analysis techniques. Furthermore, these compounds' the carbonic anhydrase (hCAs) and acetylcholinesterase (AChE) enzyme inhibition activities were investigated. They showed a highly potent inhibition effect toward AChE and hCAs with Ki values in the range of 8.30 ± 1.71 to 120.77 ± 8.61 nM for AChE, 16.97 ± 2.04 to 84.45 ± 13.78 nM for hCA I, and 14.09 ± 2.99 to 69.33 ± 17.35 nM for hCA II, respectively. Most of the synthesized imidazolium salts appeared to be more potent than the standard inhibitor of tacrine (TAC) against AChE and Acetazolamide (AZA) against CA. In the meantime, to prospect for potential synthesized imidazolium salt inhibitor(s) against AChE and hCAs, molecular docking and an ADMET-based approach were exerted.

Potential antioxidant, anticholinergic, antidiabetic and antiglaucoma activities and molecular docking of spiraeoside as a secondary metabolite of onion (Allium cepa)

Onion contains many dietary and bioactive components including phenolics and flavonoids. Spiraeoside (quercetin-4-O-β-D-glucoside) is one of the most putative flavonoids in onion. Several antioxidant techniques were used in this investigation to assess the antioxidant capabilities of spiraeoside, including 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·) scavenging, N,N-dimethyl-p-phenylenediamine radical (DMPD•+) scavenging, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical (ABTS•+) scavenging activities, cupric ions (Cu2+) reducing and potassium ferric cyanide reduction abilities. In contrast, the water-soluble α-tocopherol analogue trolox and the conventional antioxidants butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and α-tocopherol were utilized as the standards for evaluation. Spiraeoside scavenged the DPPH radicals an IC50 of 28.51 μg/mL (r2: 0.9705) meanwhile BHA, BHT, trolox, and α-tocopherol displayed IC50 of 10.10 μg/mL (r2: 0.9015), 25.95 μg/mL (r2: 0.9221), 7.059 μg/mL (r2: 0.9614) and 11.31 μg/mL (r2: 0.9642), accordingly. The results exhibited that spiraeoside had effects similar to BHT, but less potent than α-tocopherol, trolox and BHA. Also, inhibitory effects of spiraeoside were evaluated toward some metabolic enzymes including acetylcholinesterase (AChE), butyrylcholinesterase (BChE), carbonic anhydrase II (CA II) and α-glycosidase, which are related to a number of illnesses, such as Alzheimer's disease (AD), diabetes mellitus and glaucoma disorder. Spiraeoside exhibited IC50 values of 4.44 nM (r2: 0.9610), 7.88 nM (r2: 0.9784), 19.42 nM (r2: 0.9673) and 29.17 mM (r2: 0.9209), respectively against these enzymes. Enzyme inhibition abilities were compared to clinical used inhibitors including acetazolamide (for CA II), tacrine (for AChE and BChE) and acarbose (for α-glycosidase). Spiraeoside demonstrated effective antioxidant, anticholinergic, antidiabetic and antiglaucoma activities. With these properties, it has shown that Spiraeoside has the potential to be a medicine for some metabolic diseases.

Investigation of the effects of some pesticides on carbonic anhydrase isoenzymes

The aim of this study was to investigate the inhibitory effects of some pesticides known to have harmful effects on human health on carbonic anhydrase isoenzymes. Therefore, carbonic anhydrase isoenzymes (hCA I and II) were purified from human erythrocytes. The isoenzymes were purified from human erythrocytes by using an affinity column that has the chemical structure of Sepharose-4B-4-(6-amino-hexyloxy)-benzenesulfonamide. The purity of the isoenzymes was checked by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDSPAGE). It was determined that the pesticides used in this study inhibit hCA I and hCA II isoenzymes at different levels in vitro. It was determined that the strongest inhibitor for the hCA I enzyme was Carbofuran (IC50 :6.52 μM; Ki : 3.58 μM) and the weakest one was 1-Naphtol (IC50 :16.55 μM; Ki : 14.4 μM) among these pesticides. It was also found that the strongest inhibitor for the hCA II enzyme was coumatetralil (IC50 :5.06 μM; Ki : 1.62 μM) and the weakest one was Dimethachlor (IC50 14.6 μM; Ki : 8.44 μM).

Synthesis and characterization of novel acyl hydrazones derived from vanillin as potential aldose reductase inhibitors

In the polyol pathway, aldose reductase (AR) catalyzes the formation of sorbitol from glucose. In order to detoxify some dangerous aldehydes, AR is essential. However, due to the effects of the active polyol pathway, AR overexpression in the hyperglycemic state leads to microvascular and macrovascular diabetic problems. As a result, AR inhibition has been recognized as a potential treatment for issues linked to diabetes and has been studied by numerous researchers worldwide. In the present study, a series of acyl hydrazones were obtained from the reaction of vanillin derivatized with acyl groups and phenolic Mannich bases with hydrazides containing pharmacological groups such as morpholine, piperazine, and tetrahydroisoquinoline. The resulting 21 novel acyl hydrazone compounds were investigated as an inhibitor of the AR enzyme. All the novel acyl hydrazones derived from vanillin demonstrated activity in nanomolar levels as AR inhibitors with IC50 and KI values in the range of 94.21 ± 2.33 to 430.00 ± 2.33 nM and 49.22 ± 3.64 to 897.20 ± 43.63 nM, respectively. Compounds 11c and 10b against AR enzyme activity were identified as highly potent inhibitors and showed 17.38 and 10.78-fold more effectiveness than standard drug epalrestat. The synthesized molecules' absorption, distribution, metabolism, and excretion (ADME) effects were also assessed. The probable-binding mechanisms of these inhibitors against AR were investigated using molecular-docking simulations.

Synthesis, Biological Activity Evaluation and Molecular Docking of Imidazole Derivatives Possessing Hydrazone Moiety

In an attempt to identify potential active anticancer agents with low cytotoxic properties and CA inhibitors, a new series of hybrid compounds incorporating imidazole ring and hydrazone moiety as part of their structure were synthesized by aza-Michael addition reaction followed by intramolecular cyclization. The structure of synthesized compounds was elucidated using various spectral techniques. Synthesized compounds were evaluated for their in vitro anticancer (prostate cell lines; PC3) and CA inhibitory (hCA I and hCA II) activity. Among them, some compound displayed remarkable anticancer activity and CA inhibitory activity with Ki values in range of 17.53±7.19-150.50±68.87 nM against cytosolic hCA I isoform associated with epilepsy, and 28.82±14.26-153.27±55.80 nM against dominant cytosolic hCA II isoforms associated with glaucoma. Furthermore, the theoretical parameters of the bioactive molecules were calculated to establish their drug-likeness qualities. The proteins used for the calculations are prostate cancer protein (PDB ID: 3RUK and 6XXP). ADME/T analysis was carried out to examine the drug properties of the studied molecules.

Screening of Antiglaucoma, Antidiabetic, Anti-Alzheimer, and Antioxidant Activities of Astragalus alopecurus Pall-Analysis of Phenolics Profiles by LC-MS/MS

Astragalus species are traditionally used for diabetes, ulcers, leukemia, wounds, stomachaches, sore throats, abdominal pain, and toothaches. Although the preventive effects of Astragalus species against diseases are known, there is no record of the therapeutic effects of Astragalus alopecurus. In this study, we aimed to evaluate the in vitro antiglaucoma, antidiabetic, anti-Alzheimer's disease, and antioxidant activities of the methanolic (MEAA) and water (WEAA) extracts of the aerial part of A. alopecurus. Additionally, its phenolic compound profiles were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). MEAA and WEAA were evaluated for their inhibition ability on α-glycosidase, α-amylase, acetylcholinesterase (AChE), and human carbonic anhydrase II (hCA II) enzymes. The phenolic compounds of MEAA were analyzed by LC-MS/MS. Furthermore, total phenolic and flavonoid contents were determined. In this context, the antioxidant activity was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), N,N-dimethyl-p-phenylene diamine (DMPD), ferric reducing antioxidant power (FRAP), cupric ions (Cu²⁺) reducing antioxidant capacity (CUPRAC), ferric ions (Fe³⁺) reducing, and ferrous ions (Fe²⁺) chelating methods. MEAA and WEAA had IC₅₀ values of 9.07 and 2.24 μg/mL for α-glycosidase, 693.15 and 346.58 μg/mL for α-amylase, 1.99 and 2.45 μg/mL for AChE, and 147.7 and 171.7 μg/mL for hCA II. While the total phenolic amounts in MEAA and WEAA were 16.00 and 18.50 μg gallic acid equivalent (GAE)/mg extract, the total flavonoid contents in both extracts were calculated as 66.23 and 33.115 μg quercetin equivalent (QE)/mg, respectively. MEAA and WEAA showed, respectively, variable activities on DPPH radical scavenging (IC₅₀: 99.02 and 115.53 μg/mL), ABTS radical scavenging (IC₅₀: 32.21 and 30.22 µg/mL), DMPD radical scavenging (IC₅₀: 231.05 and 65.22 μg/mL), and Fe²⁺ chelating (IC₅₀: 46.21 and 33.01 μg/mL). MEAA and WEAA reducing abilities were, respectively, Fe³⁺ reducing (λ₇₀₀: 0.308 and 0.284), FRAP (λ₅₉₃: 0.284 and 0.284), and CUPRAC (λ₄₅₀: 0.163 and 0.137). A total of 35 phenolics were scanned, and 10 phenolic compounds were determined by LC-MS/MS analysis. LC-MS/MS revealed that MEAA mainly contained isorhamnetin, fumaric acid, and rosmarinic acid derivatives. This is the first report indicating that MEAA and WEAA have α-glycosidase, α-amylase, AChE, hCA II inhibition abilities, and antioxidant activities. These results demonstrate the potential of Astragalus species through antioxidant properties and enzyme inhibitor ability traditionally used in medicine. This work provides the foundation for further research into the establishment of novel therapeutics for diabetes, glaucoma, and Alzheimer's disease.

Determination of Antioxidant, Anti-Alzheimer, Antidiabetic, Antiglaucoma and Antimicrobial Effects of Zivzik Pomegran-ate (Punica granatum)—A Chemical Profiling by LC-MS/MS)

Zivzik pomegranate (Punica granatum) has recently sparked considerable interest due to its nutritional and antioxidant properties. To evaluate the antioxidant capacities of P. granatum juice, ethanol (EEZP), and water (WEZP) extracts from peel and seed, the antioxidant methods of 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid radical (ABTS•+) scavenging, 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH•) scavenging, Fe3+-2,4,6-tris(2-pyridyl)-S-triazine (TPTZ) reducing, Fe3+ reducing, and Cu2+ reducing methods were used. The antioxidant capacities of samples were compared with the most commonly used synthetic antioxidants, i.e., BHA, BHT, α-tocopherol, and Trolox. In terms of setting an example, the IC50 values of EEZP for ABTS•+ and DPPH• scavenging activities were found to be lower than standards, at 5.9 and 16.1 μg/mL, respectively. The phenolic and flavonoid contents in EEZP peel were 59.7 mg GAE/g and 88.0 mg QE/g, respectively. Inhibition of α-glycosidase, α-amylase, acetylcholinesterase, and human carbonic anhydrase II (hCA II) enzymes was also investigated. EEZP demonstrated IC50 values of 7.3 μg/mL against α-glycosidase, 317.7 μg/mL against α-amylase, 19.7 μg/mL against acetylcholinesterase (AChE), and 106.3 μg/mL against CA II enzymes. A total of 53 phenolic compounds were scanned, and 30 compounds were determined using LC-MS/MS. E. coli and S. aureus bacteria were resistant to all four antibiotics used as standards in hospitals.

Analysis of bioactive compounds using LC-ESI-MS/MS, cytotoxic, antimicrobial effects, and enzyme activities from Cyclotrichium origanifolium

Cyclotrichium origanifolium is a medicinal plant belonging to the Lamiaceae family. In this study, phenolic content analysis, antimicrobial effects, and cytotoxic effects of extracts of C. origanifolium were investigated. In the extracts, phenolic compound analysis by the liquid chromatography-electrospray ionization-tandem mass spectrometry method, antimicrobial effect by the minimum inhibition concentration method, and cytotoxic effect on human dermal fibroblasts (HDF), glioblastoma cell (U87), ovarian adenocarcinoma cell (Skov-3), and human colorectal adenocarcinoma cell (CaCo-2) cancer cell lines were investigated. Cytotoxicity analyses were performed by the MTT method. In addition, the GST and AChE enzyme activities of the extracts were also measured. Around 18 compounds were detected in both the methanol and ethanol extract. It was found that the best antimicrobial effect on Gram-negative Pseudomonas aeruginosa was on methanol extract, while the ethanol extract was on Candida albicans fungus (respectively, 2.50 mg/ml, 5.0 μg/ml). A 500 μg/ml of methanol extract has been shown to have cytotoxic activity high effect on HDF cells. GST and AChE activity were found to decrease in a concentration-dependent manner.

Comprehensive Metabolite Profiling of Berdav Propolis Using LC-MS/MS: Determination of Antioxidant, Anticholinergic, Antiglaucoma, and Antidiabetic Effects

Propolis is a complex natural compound that honeybees obtain from plants and contributes to hive safety. It is rich in phenolic and flavonoid compounds, which contain antioxidant, antimicrobial, and anticancer properties. In this study, the chemical composition and antioxidant activities of propolis were investigated; ABTS•+, DPPH• and DMPD•+ were prepared using radical scavenging antioxidant methods. The phenolic and flavonoid contents of propolis were 53 mg of gallic acid equivalent (GAE)/g and 170.164 mg of quercetin equivalent (QE)/g, respectively. The ferric ion (Fe3+) reduction, CUPRAC and FRAP reduction capacities were also studied. The antioxidant and reducing capacities of propolis were compared with those of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol and Trolox reference standards. The half maximal inhibition concentration (IC50) values of propolis for ABTS•+, DPPH• and DMPD•+ scavenging activities were found to be 8.15, 20.55 and 86.64 μg/mL, respectively. Propolis extract demonstrated IC50 values of 3.7, 3.4 and 19.6 μg/mL against α-glycosidase, acetylcholinesterase (AChE) and carbonic anhydrase II (hCA II) enzyme, respectively. These enzymes' inhibition was associated with diabetes, Alzheimer's disease (AD) and glaucoma. The reducing power, antioxidant activity and enzyme inhibition capacity of propolis extract were comparable to those demonstrated by the standards. Twenty-eight phenolic compounds, including acacetin, caffeic acid, p-coumaric acid, naringenin, chrysin, quinic acid, quercetin, and ferulic acid, were determined by LC-MS/MS to be major organic compounds in propolis. The polyphenolic antioxidant-rich content of the ethanol extract of propolis appears to be a natural product that can be used in the treatment of diabetes, AD, glaucoma, epilepsy, and cancerous diseases.

Investigation on Hydrazonobenzenesulfonamides as Human Carbonic Anhydrase I, II, IX and XII Inhibitors

A small series of hydrazonobenzenesulfonamides was designed, synthesized and studied for their human carbonic anhydrase (hCA) inhibitory activity. The synthesized compounds were evaluated against hCA I, II, IX and XII isoforms using acetazolamide (AAZ) as the standard inhibitor. Various hydrazonosulfonamide derivatives showed inhibitory activity at low nanomolar levels with selectivity against the cytosolic hCA II isoform, as well as the transmembrane, tumor-associated enzymes hCA IX and XII. The most potent and selective hydrazones 8, 9, 10, 11, 19 and 24 were docked into isoforms I, II, IX and XII to better understand their activity and selectivity for the different CA isoforms.

Synthesis of Novel Bromophenol with Diaryl Methanes—Determination of Their Inhibition Effects on Carbonic Anhydrase and Acetylcholinesterase

In this work, nine new bromophenol derivatives were designed and synthesized. The alkylation reactions of (2-bromo-4,5-dimethoxyphenyl)methanol (7) with substituted benzenes 8–12 produced new diaryl methanes 13–17. Targeted bromophenol derivatives 18–21 were synthesized via the O-Me demethylation of diaryl methanes with BBr3. Moreover, the synthesized bromophenol compounds were tested with some metabolic enzymes such as acetylcholinesterase (AChE), carbonic anhydrase I (CA I), and II (CA II) isoenzymes. The novel synthesized bromophenol compounds showed Ki values that ranged from 2.53 ± 0.25 to 25.67 ± 4.58 nM against hCA I, from 1.63 ± 0.11 to 15.05 ± 1.07 nM against hCA II, and from 6.54 ± 1.03 to 24.86 ± 5.30 nM against AChE. The studied compounds in this work exhibited effective hCA isoenzyme and AChE enzyme inhibition effects. The results show that they can be used for the treatment of glaucoma, epilepsy, Parkinson’s as well as Alzheimer’s disease (AD) after some imperative pharmacological studies that would reveal their drug potential.

Phthalimide-tethered imidazolium salts: Synthesis, characterization, enzyme inhibitory properties, and in silico studies

A series of new imidazolium salts were prepared in good yield by the reaction between 1-alkylimidazole and a variety of alkyl halides. The structures of the compounds were identified by FT-IR, ¹ H NMR, and ¹³ C NMR spectroscopy, elemental analysis, and mass spectrometry. The crystal structure of 1b was determined by the single-crystal X-ray diffraction method. The phthalimide-tethered imidazolium salts exhibited inhibition abilities toward acetylcholinesterase (AChE) and human carbonic anhydrases (hCAs) I and II, with K_i values in the range of 24.63 ± 3.45 to 305.51 ± 35.98 nM for AChE, 33.56 ± 3.71 to 218.01 ± 25.21 nM for hCA I and 17.75 ± 0.96 to 308.67 ± 13.73 nM for hCA II. The results showed that the new imidazolium salts can play a key role in the treatment of Alzheimer's disease, epilepsy, glaucoma, and leukemia, which is related to their inhibition abilities of hCA I, hCA II, and AChE. Molecular docking and in silico absorption, distribution, metabolism, excretion and toxicity studies were used to look into how the imidazolium salts interacted with the specific protein targets. To better visualize and understand the binding positions and the influence of the imidazolium salts on hCA I, hCA II, and AChE conformations, each one was subjected to molecular docking simulations.

The palladium-based complexes bearing 1,3-dibenzylbenzimidazolium with morpholine, triphenylphosphine, and pyridine derivate ligands: synthesis, characterization, structure and enzyme inhibitions

The palladium-based complexes bearing N-heterocyclic carbene (NHC) ligand have long attracted attention as active catalysts for many catalytic reactions. Recently, the biological activities of these complexes, which are stable to air and moisture, have also been wondered. With the aim, we report the synthesis of a series of (NHC)Pd(Br2)(L) complexes (NHC: 1,3-dibenzylbenzimidazolium, L: morpholine, triphenylphosphine, pyridine, 3-chloropyridine, and 2-aminopyridine). All complexes were characterized by NMR (1H and 13C), FTIR spectroscopic and elemental analysis techniques. In addition, the single crystal structures of the complex 3, 4, and 6 were determined through single crystal x-ray crystallographic method. Furthermore, the carbonic anhydrase I and II isoenzymes (hCAs) and acetylcholinesterase (AChE) inhibition effects of these palladium-based complexes bearing NHC ligand were investigated. They showed highly potent inhibition effect with Ki values are between 10.06 ± 1.49-68.56 ± 11.53 nM for hCA I isoenzyme, 7.74 ± 0.66 to 49.39 ± 6.50 nM for hCA II isoenzyme and 22.83 ± 3.21 to 64.09 ± 9.05 nM for AChE enzyme.

Design, Synthesis and Biological Evaluation of New 3,4-Dihydro-2(1H)-Quinolinone-Dithiocarbamate Derivatives as Multifunctional Agents for the Treatment of Alzheimer’s Disease

Background

Alzheimer’s disease (AD) belongs to neurodegenerative disease, and the increasing number of AD patients has placed a heavy burden on society, which needs to be addressed urgently. ChEs/MAOs dual-target inhibitor has potential to treat AD according to reports.

Purpose

To obtain effective multi-targeted agents for the treatment of AD, a novel series of hybrid compounds were designed and synthesized by fusing the pharmacophoric features of 3,4-dihydro-2 (1H)-quinolinone and dithiocarbamate.

Methods

All compounds were evaluated for their inhibitory abilities of ChEs and MAOs. Then, further biological activities of the most promising candidate 3e were determined, including the ability to cross the blood-brain barrier (BBB), kinetics and molecular model analysis, cytotoxicity in vitro and acute toxicity studies in vivo.

Results

Most compounds showed potent and clear inhibition to AChE and MAOs. Among them, compound 3e was considered to be the most effective and balanced inhibitor to both AChE and MAOs (IC₅₀=0.28 µM to eeAChE; IC₅₀=0.34 µM to hAChE; IC₅₀=2.81 µM to hMAO-B; IC₅₀=0.91 µM to hMAO-A). In addition, 3e showed mixed inhibition of hAChE and competitive inhibition of hMAO-B in the enzyme kinetic studies. Further studies indicated that 3e could penetrate the BBB and showed no toxicity on PC12 cells and HT-22 cells when the concentration of 3e was lower than 12.5 µM. More importantly, 3e lacked acute toxicity in mice even at high dose (2500 mg/kg, P.O.).

Conclusion

This work indicated that compound 3e with a six-carbon atom linker and a piperidine moiety at terminal position was a promising candidate and was worthy of further study.

Synthesis of Novel Tritopic Hydrazone Ligands: Spectroscopy, Biological Activity, DFT, and Molecular Docking Studies

Polytopic organic ligands with hydrazone moiety are at the forefront of new drug research among many others due to their unique and versatile functionality and ease of strategic ligand design. Quantum chemical calculations of these polyfunctional ligands can be carried out in silico to determine the thermodynamic parameters. In this study two new tritopic dihydrazide ligands, N’2, N’6-bis[(1E)-1-(thiophen-2-yl) ethylidene] pyridine-2,6-dicarbohydrazide (L1) and N’2, N’6-bis[(1E)-1-(1H-pyrrol-2-yl) ethylidene] pyridine-2,6-dicarbohydrazide (L2) were successfully prepared by the condensation reaction of pyridine-2,6-dicarboxylic hydrazide with 2-acetylthiophene and 2-acetylpyrrole. The FT-IR, 1H, and 13C NMR, as well as mass spectra of both L1 and L2, were recorded and analyzed. Quantum chemical calculations were performed at the DFT/B3LYP/cc-pvdz/6-311G+(d,p) level of theory to study the molecular geometry, vibrational frequencies, and thermodynamic properties including changes of ∆H, ∆S, and ∆G for both the ligands. The optimized vibrational frequency and (1H and 13C) NMR obtained by B3LYP/cc-pvdz/6-311G+(d,p) showed good agreement with experimental FT-IR and NMR data. Frontier molecular orbital (FMO) calculations were also conducted to find the HOMO, LUMO, and HOMO−LUMO gaps of the two synthesized compounds. To investigate the biological activities of the ligands, L1 and L2 were tested using in vitro bioassays against some Gram-negative and Gram-positive bacteria and fungus strains. In addition, molecular docking was used to study the molecular behavior of L1 and L2 against tyrosinase from Bacillus megaterium. The outcomes revealed that both L1 and L2 can suppress microbial growth of bacteria and fungi with variable potency. The antibacterial activity results demonstrated the compound L2 to be potentially effective against Bacillus megaterium with inhibition zones of 12 mm while the molecular docking study showed the binding energies for L1 and L2 to be −7.7 and −8.8 kcal mol−1, respectively, with tyrosinase from Bacillus megaterium.

Discovery of new carbonic anhydrase IX inhibitors as anticancer agents by toning the hydrophobic and hydrophilic rims of the active site to encounter the dual-tail approach

The hydrophobic and the hydrophilic rims in the active site of human carbonic anhydrase IX (hCA IX) which as well contains a zinc ion as part of the catalytic core, were simultaneously matched to design and synthesize potent and selective inhibitors using a dual-tail approach. Seventeen new compounds, 5a-q, were designed to have the benzenesulfonamide moiety as a zinc binding group. In addition, N-substituted hydrazone and N-phenyl fragments were chosen as the hydrophilic and hydrophobic parts, respectively to achieve favorable interactions with the corresponding halves of the active site. All synthesized compounds successfully suppressed the CA IX, with IC₅₀ values in nanomolar range from 13.3 to 259 nM. Compounds, 5h, 5c, 5m, 5e, and 5k were the top-five compounds efficiently inhibited the tumor-related CA IX isoform in the low nanomolar range (K_I = 13.3, 22.6, 25.8, 26.9 and 27.2 nM, respectively). The target compounds 5a-q developed remarkable selectivity toward the tumor-associated isoforms (hCA IX and XII) over the off-target isoforms (hCA I and II). Furthermore, they were assessed for their anti-proliferative activity, according to US-NCI protocol, against a panel of fifty-nine cancer cell lines. Compounds 5d, 5k and 5o were passed the criteria for activity and scheduled automatically for evaluation at five concentrations with 10-fold dilutions. Compound 5k exhibited significant in vitro anticancer activity with GI₅₀-MID; 8.68 μM compared to compounds 5d and 5o with GI₅₀-MID; 25.76 μM and 34.97 μM respectively. The most selective compounds 5h and 5k were further screened for their in vitro cytotoxic activity against SK-MEL-5, HCC-2998 and RXF 393 cancer cell lines under hypoxic conditions. Furthermore, 5k was screened for cell cycle disturbance, apoptosis induction and intracellular reactive oxygen species (ROS) production in SK-MEL-5 cancer cells. Finally, molecular docking studies were performed to gain insights for the plausible binding interactions and affinities for selected compounds within hCA IX active site.

Recent developments in the green synthesis of biologically relevant cinnolines and phthalazines

Both cinnolines and phthalazines are heterocyclic compounds which have a wide range of biological activities and pharmacological profiles. This work represents the recent advances in the green synthesis of cinnolines and phthalazines as 1,2 and 2,3-diazanaphalenes were cited. The docking studies and mode of action for key scaffolds were also reported.

Camphor nitroimine: a key building block in unusual transformations and its applications in the synthesis of bioactive compounds

The development of new drugs requires a lot of time and high financial investments. It involves a research network in which there is the participation of several researchers from different areas. For a new drug to reach the market, thousands of substances must be evaluated. There are several tools for this and the use of suitable building blocks can facilitate the process by allowing a lead compound to have suitable parameters. These compounds are key structures containing special functional groups that also permit adequate synthetic transformations, leading to several structures of interest in a short period of time. In this review, the use of camphor nitroimine as a potential key building block is explored. Derived from camphor, an abundant natural product present in various plant species, this nitroimine has proved to be quite versatile, allowing the access to substances with miscellaneous biological activities, ligands to asymmetric catalysis, asymmetric oxidants, O-N transfer agents and other applications. Its easy conversion to camphecene and other derivatives is described, as well as their applications in medicinal chemistry. Druglikeness analyses were performed on these studied agents as well as on their bioactive derivatives in order to assess their use in the development of potential drugs.

Oleuropein and Verbascoside - Their Inhibition Effects on Carbonic Anhydrase and Molecular Docking Studies

Recently, carbonic anhydrase (CA, E.C.4.2.1.1) inhibitors from natural product have paved the way for novel drug design in the treatment and prevention of some global diseases such as glaucoma, diabetes, and cancer. For this purpose, the inhibition effects of oleuropein and verbascoside from olive (Olea europaea L.) oil on human carbonic anhydrase I, and II (hCA I, and II) isoenzymes were evaluated in the current study. The inhibition effects of both natural compounds were determined by the esterase activity (in vitro). IC₅₀ value of oleuropein and verbascoside was calculated as 1.57 and 1.73 µM for hCA I isoenzyme, respectively. At the same manner, K _i values were determined as 1.25 ± 0.42 and 2.00 ± 0.42 µM, respectively. Then, IC₅₀ value of each compound for hCA II isoenzyme was calculated as 2.23 and 1.90 µM, respectively. Similarly, K _i values were determined as 2.37 ± 0.87 µM and 1.49 ± 0.33 µM, respectively. Also, the inhibitory effects and potent binding mechanisms of oleuropein and verbascoside on hCA I, and II isoenzymes were realized by molecular docking studies. Consequently, both natural phenolic compounds demonstrated the potent inhibition profiles against the both isoenzymes. Therefore, we believe that these results may break new ground in the drug development for the treatment of some global disorders.