Dynamics of small molecule-enzyme interactions: Novel benzenesulfonamides as multi-target agents endowed with inhibitory effects against some metabolic enzymes.

In contemporary medicinal chemistry, employing a singular small molecule to concurrently multi-target disparate molecular entities is emerging as a potent strategy in the ongoing battle against metabolic disease. In this study, we present the meticulous design, synthesis, and comprehensive biological evaluation of a novel series of 1,2,3-triazolylmethylthio-1,3,4-oxadiazolylbenzenesulfonamide derivatives (8a-m) as potential multi-target inhibitors against human carbonic anhydrase (EC.4.2.1.1, hCA I/II), α-glycosidase (EC.3.2.1.20, α-GLY), and α-amylase (EC.3.2.1.1, α-AMY). Each synthesized sulfonamide underwent rigorous assessment for inhibitory effects against four distinct enzymes, revealing varying degrees of hCA I/II, a-GLY, and a-AMY inhibition across the tested compounds. hCA I was notably susceptible to inhibition by all compounds, demonstrating remarkably low inhibition constants (KI) ranging from 42.20 ± 3.90 nM to 217.90 ± 11.81 nM compared to the reference standard AAZ (KI of 439.17 ± 9.30 nM). The evaluation against hCA II showed that most of the synthesized compounds exhibited potent inhibition effects with KI values spanning the nanomolar range 16.44 ± 1.53-70.82 ± 4.51 nM, while three specific compounds, namely 8a-b and 8d, showcased lower inhibitory potency than other derivatives that did not exceed that of the reference drug AAZ (with a KI of 98.28 ± 1.69 nM). Moreover, across the spectrum of synthesized compounds, potent inhibition profiles were observed against diabetes mellitus-associated α-GLY (KI values spanning from 0.54 ± 0.06 µM to 5.48 ± 0.50 µM), while significant inhibition effects were noted against α-AMY, with IC50 values ranging between 0.16 ± 0.04 µM and 7.81 ± 0.51 µM) compared to reference standard ACR (KI of 23.53 ± 2.72 µM and IC50 of 48.17 ± 2.34 µM, respectively). Subsequently, these inhibitors were evaluated for their DPPH· and ABTS+· radical scavenging activity. Moreover, molecular docking investigations were meticulously conducted within the active sites of hCA I/II, α-GLY, and α-AMY to provide comprehensive elucidation and rationale for the observed inhibitory outcomes.

Naphthoquinones and anthraquinones: Exploring their impact on acetylcholinesterase enzyme activity.

The identification of novel acetylcholinesterase inhibitors holds significant relevance in the treatment of Alzheimer's disease (AD), the prevailing form of dementia. The exploration of alternative inhibitors to the conventional acetylcholinesterase inhibitors is steadily gaining prominence. Quinones, categorized as plant metabolites, represent a specific class of compounds. In this study, the inhibitory effects of various naphthoquinone derivatives, along with anthraquinone and its derivatives, on the acetylcholinesterase (AChE) enzyme were investigated for this purpose. An in vitro investigation was conducted to examine the effects of these compounds in order to clarify the possible mechanism of inhibition in the interaction between the enzyme and chemicals. In addition, an in silico investigation was carried out to understand the conceivable inhibitor binding process to the enzyme's active site. The acquired outcomes corroborated the in vitro results. The AChE enzyme was found to be effectively inhibited by both naphthoquinones and anthraquinones, with inhibition constant (KI) values ranging from 0.014 to 0.123 µM (micormolar). The AChE enzyme was inhibited differently by this quinone and its derivatives. Although derivatives of naphthoquinone and anthraquinone exhibited a competitive inhibitory effect, derivatives of anthraquinone exhibited a noncompetitive inhibition effect. Furthermore, because it had the lowest KI value of any of these substances, 1,5-dihydroxyanthraquinone (1c) was shown to be the most potent inhibitor. The findings will add to the body of knowledge on the creation of fresh, potent, and successful treatment approaches.

Evaluation of the relationship among gene expressions and enzyme activities with antioxidant role and presenilin 1 expression in Alzheimer's disease.

It is known that oxidative stress originating from reactive oxygen species plays a role in the pathogenesis of Alzheimer's disease. In this study, the role of antioxidant status associated with oxidative stress in Alzheimer's disease was investigated. Peripheral blood samples were obtained from 28 healthy individuals (as control) and 28 Alzheimer's patients who met the National Institute of Neurological and Communicative Diseases and Stroke/Alzheimer's Disease and Related Disorders Association criteria. Catalase, glutathione S-transferase and paraoxonase 1 enzyme activities in blood plasma and glutathione S-transferase enzyme activities in erythrocytes were determined by spectrophotometer. Catalase, glutathione S-transferase and presenilin 1 gene expressions in leukocytes were determined using qRT-PCR. Data were analysed with SPSS one-way anova, a LSD post hoc test at p < 0.05. The activity of each enzyme was significantly reduced in Alzheimer's patients compared to control. The catalase gene expression level did not change compared to the control. Glutathione S-transferase and presenilin 1 gene expression levels were increased compared to the control.

Pyrimidines: Molecular docking and inhibition studies on carbonic anhydrase and cholinesterases.

Alzheimer's disease (AD) is a neurodegenerative disorder. The disease is characterized by dementia, memory impairment, cognitive impairment, and speech impairment. Cholinesterases (ChEs; AChE, acetylcholinesterase and BChE, butyrylcholinesterase) inhibitors and their benefits of cholinergic replacement in the treatment of AD have been researched and documented by scientists in various ways to date. Recent studies prove that human carbonic anhydrases (hCAs) are also one of the important targets in the treatment of AD. Therefore, the development of new agents that can simultaneously modulate the various mechanisms or targets involved in the AD pathway may be a powerful strategy to treat AD, the current disease. Considering these data, the effects of the pyrimidines (1-7) were investigated in this study for the discovery and development of multitargeted ChEs and hCAs inhibitors associated with AD. In addition, the molecular docking analysis of the 4-amino-2-choloropyrimidine (2) was performed to understand the binding interactions on the active site of the enzyme. All compounds (1-7) showed satisfactory enzyme inhibitory potency in micromolar concentrations against AChE, BChE, hCAI, and hCAII with KI values ranging from 0.099 to 0.241 µM, from 1.324 to 3.418 µM, from 0.201 to 0.884 µM, from 1.867 to 3.913 µM, respectively. Due to their ChEs and hCAs inhibition, these compounds (1-7) may be considered as leads for investigations in neurodegenerative diseases. All these results revealed that the 4-amino-5,6-dichloropyrimidine (7) (KI value of 0.201 ± 0.041 µM for hCA I), the 4-amino-6-hydroxypyrimidine (4) (KI value of 1.867 ± 0.296 µM for hCA II), the 4-amino-5,6-dichloropyrimidine (7) (KI value of 0.099 ± 0.008 µM for AChE), and the 4-amino-2-chloropyrimidine (2) (KI value of 1.324 ± 0.273 µM for BChE) from the pyrimidines in this series were the most promising derivatives, as they exhibited a good multifunctional inhibition at all experimental levels and in the in silico validation against these enzymes, for the treatment of AD.

Recombinant human carbonic anhydrase VII: Purification, characterization, inhibition, and molecular docking studies.

Human carbonic anhydrase VII (hCA VII), a cytosolic enzyme, defends against oxidative stress by preventing reactive oxygen species from forming. In our study, first, hCA VII was cloned into Escherichia coli (One Shot Mach1-T1R) strain by using cDNA of the human brain and successfully expressed. The integrity of the plasmid generated by colony PCR was checked, and after, for protein expression, the plasmid was transformed into E. coli BL21 (DE-3) strain. hCA VII expression was observed after 6 h of isopropyl-D-1-thiogalactopyranoside (IPTG) induction. The fusion protein containing hexahistidine (6xHis) was purified with 7.02 EU/mg of specific activity, had 48.07% of purification yield, and approximately 21-folds using a ProbondTM nickel chelating resin affinity column. Then, both molecular mass determination and purity control of the purified recombinant enzyme was done by SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis). The mass of the SUMO-hCA VII fusion protein was calculated as 46.77 kDa. As a result of Western blot analysis using anti-His G-HRP antibody, the fusion protein was detected as approximately 45 kDa. Furthermore, the characterization assays and in vitro inhibition studies were done for the recombinant enzyme. KI values of these agents were found between 0.29 µM and 157.6 mM. Finally, molecular docking investigations of these antibiotics were undertaken to understand further the binding interactions on the active site of this recombinant enzyme.

Novel bis-ureido-substituted sulfaguanidines and sulfisoxazoles as carbonic anhydrase and acetylcholinesterase inhibitors.

To discover alternative substances to compounds used to treat many diseases, especially treating Alzheimer's disease (AD) and Parkinson's disease targeting carbonic anhydrase (hCA) and acetylcholinesterase (AChE) enzymes, is important. For this purpose, a series of novel bis-ureido-substituted sulfaguanidine (SG1-4) and sulfisoxazole (SO1-4) derivatives were synthesized, and their inhibitory capacities were screened against hCA isoenzymes (hCA I and II) and AChE. Possible binding mechanisms of inhibitors to the active site were elucidated by in silico studies, and the results were supported by in vitro results. Moreover, the percent radical scavenging capacities of the derivatives were also evaluated. The derivatives (SG1-4 and SO1-4) were more effective against hCAs compared to standard drug acetazolamide (KI values of 98.28-439.17 nM for hCA I and II, respectively) and exhibited the highest inhibition with the KIs in the ranges of 2.54 ± 0.50-41.02 ± 7.52 nM for hCA I, 11.20 ± 2.97-67.14 ± 13.58 nM for hCA II, and 257.60 ± 27.84-442.60 ± 52.13 nM for AChE. Also, compounds SG1 and SO1 also showed ABTS radical scavenging activity at the rate of 70% and 78%, respectively. These results will contribute to the literature for the rational design and synthesis of new potent and selective inhibitors targeting hCAs and AChE with multifunctional effects such as radical scavenging as well as inhibition. This study focused on the synthesis and inhibitory effects of bis-ureido-substituted sulfaguanidine (SG1-4) and sulfisoxazole (SO1-4) derivatives against human hCA I and II isoforms and AChE. In order to test synthesized derivatives' free radical scavenging potentials were the DPPH and ABTS assays. In silico studies elucidated possible binding mechanisms of inhibitors to the active site.

Synthesis and Characterization of Novel 1,3-Diaryltriazene-Substituted Sulfaguanidine Derivatives as Selective Carbonic Anhydrase Inhibitors: Biological Evaluation, in Silico ADME/T and Molecular Docking Study.

Sulfonamide compounds known as human carbonic anhydrase (hCA) inhibitors are used in the treatment of many diseases such as epilepsy, antibacterial, glaucoma, various diseases. 1,3-diaryl-substituted triazenes and sulfaguanidine are used for therapeutic purposes in many drug structures. Based on these two groups, the synthesis of new compounds is important. In the present study, the novel 1,3-diaryltriazene-substituted sulfaguanidine derivatives (SG1-13) were synthesized and fully characterized by spectroscopic and analytic methods. Inhibitory effect of these compounds on the hCA I and hCA II was screened as in vitro. All the series of synthesized compounds have been identified as potential hCA isoenzymes inhibitory with KI values in the range of 6.44±0.74-86.85±7.01 nM for hCA I and with KI values in the range of 8.16±0.40-77.29±9.56 nM for hCA II. Moreover, the new series of compounds showed a more effective inhibition effect than the acetazolamide used as a reference. The possible binding positions of the compounds with a binding affinity to the hCA I and hCA II was demonstrated by in silico studies. In conclusion, compounds with varying degrees of affinity for hCA isoenzymes have been designed and as selective hCA inhibitors. These compounds may be potential alternative agents that can be used to treat or prevent diseases associated with glaucoma and hCA inhibition.

Determination of the inhibition profiles of pyrazolyl-thiazole derivatives against aldose reductase and α-glycosidase and molecular docking studies.

Aldose reductase (AR) is the first and rate-limiting enzyme of the polyol pathway, which converts glucose to sorbitol in an NADPH-dependent reaction. α-Glycosidase breaks down starch and disaccharides to glucose. Hence, inhibition of these enzymes can be regarded a considerable approach in the treatment of diabetic complications. AR was purified from sheep liver using simple chromatographic methods. The inhibitory effects of pyrazolyl-thiazoles ((3aR,4S,7R,7aS)-2-(4-{1-[4-(4-bromophenyl)thiazol-2-yl]-5-(aryl)-4,5-dihydro-1H-pyrazol-3-yl}phenyl)-3a,4,7,7a-tetrahydro-1H-4,7-methanoisoindole-1,3(2H)-dione derivatives; 3a-i) on AR and α-glycosidase enzymes were investigated. All compounds showed a good inhibitory action against AR and α-glycosidase. Among these compounds, compound 3d exhibited the best inhibition profiles against AR, with a Ki value of 7.09 ± 0.19 µM, whereas compound 3e showed the lowest inhibition effects, with a Ki value of 21.89 ± 1.87 µM. Also, all compounds showed efficient inhibition profiles against α-glycosidase, with Ki values in the range of 0.43 ± 0.06 to 2.30 ± 0.48 µM, whereas the Ki value of acarbose was 12.60 ± 0.78 µM. Lastly, molecular modeling approaches were implemented to predict the binding affinities of compounds against AR and α-glycosidase. In addition, the ADME analysis of the molecules was performed.

The Influence of Some Nonsteroidal Anti-inflammatory Drugs on Metabolic Enzymes of Aldose Reductase, Sorbitol Dehydrogenase, and α-Glycosidase: a Perspective for Metabolic Disorders.

Pain, as a sensible alarm signal of living organisms to avoid tissue damage, is a common and debilitating consequence of a lot of disorders and diseases. The management of chronic pain is particularly challenging. For pain treatment, many analgesic drugs are used for their therapeutic effects. In this study, some nonsteroidal anti-inflammatory drugs including etofenamate, meloxicam, diclofenac, and tenoxicam were tested against α-glycosidase from Saccharomyces cerevisiae, sorbitol dehydrogenase (SDH), and aldose reductase (AR) enzymes from sheep liver. Nonsteroidal anti-inflammatory drugs demonstrated useful inhibition properties against α-glycosidase, AR, and SDH enzymes. Ki values were found in the range of 11.93 ± 3.77-364.88 ± 40.01 µM for α-glycosidase, 3.36 ± 1.08µM-17.68 ± 3.39 mM for AR, and 1.68 ± 0.02 µM-30.98 ± 14.31 mM for SDH. They can be selective drugs as antidiabetic agents, because of their inhibitory properties against SDH, α-glycosidase, and AR enzymes.

Inhibition effects of quinones on aldose reductase: Antidiabetic properties.

Diabetes mellitus is a chronic metabolic disease characterized by abnormal glucose metabolism. Aldose reductase (AR) is the first enzyme in the polyol pathway and converts glucose to sorbitol. It plays a vital role as a glucose reducing agent and is involved in the pathophysiology of diabetic complications. In this study, we purified AR from sheep kidney with a specific activity of 2.00 EU/mg protein and 133.33- fold purification After the purification of the AR enzyme, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed and the molecular weight of the enzyme was found approximately as 38 kDa. The inhibition effects of eight quinones were studied against AR. The quinones were potent inhibitors of AR with Ki values in the range of 0.07-20.04 µM. Anthraquinone showed the best potential inhibitory effects against AR. All compounds exhibited noncompetitive inhibition against AR. These compounds may be selective inhibitors of this enzyme. AR inhibition is an essential strategy for the attenuation and prevention of diabetic complications.