Carbonic anhydrase inhibitors: guaiacol and catechol derivatives effectively inhibit certain human carbonic anhydrase isoenzymes (hCA I, II, IX and XII)

Design, synthesis and in silico insights of novel 1,2,3-triazole benzenesulfonamide derivatives as potential carbonic anhydrase IX and XII inhibitors with promising anticancer activity

Novel 1,2,3-triazole benzenesulfonamide derivatives were designed as inhibitors for the tumor- related hCA IX and XII isoforms. Most of the synthesized compounds showed good inhibitory activity against hCA IX and hCA XII isoforms. Compounds 4d, 5h and 6b, exhibited remarkable activity as hCA IX inhibitors, with Ki values in the range of 0.03 to 0.06 µM, more potent than AAZ. Additionally, compounds 5b and 6d, efficiently inhibited hCA XII isoform, with Ki value of 0.02 µM, respectively, similar to AAZ. Further investigation for those potent derivatives against MCF-7, Hep-3B and WI-38 cell lines was achieved. Compounds 4d and 6d exerted dual cytotoxic activity against MCF-7 and Hep-3B cell lines, with IC50 values of 3.35 & 2.12 µM against MCF-7 cell line and 1.72 & 1.56 µM against Hep-3B cell line, with high SI values ranged from 8.92 to 17.38 on both of the cell lines. Besides, they showed a high safety profile against normal human cell line, WI-38. Moreover, compound 5h had better cytotoxic effect on MCF-7 than the reference, DOX, with IC50 value of 4.02 µM. While, compounds 5b and 6b showed higher activity against Hep-3B if compared to the reference drug, 5-FU. From ADME study, compounds 4d, 5b, 6b and 6d obeyed Lipinski's rule of five, and they might be orally active derivatives, while, compound 5h exerted less oral bioavailability than the reference standard acetazolamide. Molecular docking and MDS studies predicted the binding mode and the stability of the target compounds inside hCA IX and hCA XII active sites, especially for compounds 5b and 6b.

Synthesis, Structural Elucidation, In Silico and In Vitro Studies of New Class of Methylenedioxyphenyl-Based Amide Derivatives as Potential Myeloperoxidase Inhibitors for Cardiovascular Protection

Novel methylenedioxyphenyl-based amides, especially N-(4-methoxybenzyl)-6-nitrobenzo-[1,3]-dioxole-5-carboxamide (MDC) and N-(3-acetylphenyl)-6-nitrobenzo-[1,3]-dioxole-5-carboxamide (ADC), potential cardiovascular preventive agents, are successfully synthesized, and their chemical structures are verified by 1H and 13C NMR, Fourier transform infrared (FT-IR), high-resolution mass spectrometry (HRMS), and single-crystal X-ray diffraction (SC-XRD) analyses. Data obtained from SC-XRD reveal that MDC and ADC are both monoclinic molecules with Z = 2 and 4, respectively. From density functional theory (DFT) calculations, 3.54 and 3.96 eV are the energy gaps of the optimized MDC and ADC structures, respectively. MDC and ADC exhibit an electrophilicity index value of more than 1.5 eV, suggesting that they can act as an electrophile, facilitating bond formation with biomolecules. Hirshfeld surface analysis demonstrates that more than 25% of atomic interactions in both MDC and ADC are from H···H interactions. Based on pharmacokinetic predictions, MDC and ADC exhibit drug-like properties, and molecular docking simulations revealed favorable interactions with active site pockets. Both MDC and ADC achieved higher docking scores of -7.74 and -7.79 kcal/mol, respectively, with myeloperoxidase (MPO) protein. From docking results, MPO was found to be most favorable followed by dipeptidyl peptidase-4 (DPP-4) and α-glucosidase (α-GD). Antioxidant, anti-inflammatory, and in vitro enzymatic studies of MDC and ADC indicate that MDC is more selective toward MPO and more potent than ADC. The application of MDC to inhibit myeloperoxidase could be ascertained to reduce the cardiovascular risk factor. This can be supported from the results of computational docking (based on hydrogen bonding and docking score), in vitro antioxidant and anti-inflammatory properties, and MPO enzymatic inhibition (based on the percentage of inhibition and IC50 values).

Design, synthesis, and molecular docking studies of benzimidazole-1,3,4-triazole hybrids as carbonic anhydrase I and II inhibitors

In this study, with an aim to develop novel heterocyclic hybrids as potent enzyme inhibitors, we synthesized a series of 10 novel 2-(4-(4-ethyl-5-(2-(substitutedphenyl)-2-oxo-ethylthio)-4H-1,2,4-triazol-3-yl)-phenyl)-5,6-dimethyl-1H-benzimidazole (5a-5j) derivatives and characterized by 1 H-NMR, 13 C-NMR, and HRMS. These compounds were evaluated for their inhibitory activity against hCA I and hCA II. All the compounds exhibited good hCA I and hCA II inhibitory activities with IC50 values in range of 1.288 μM-3.122 μM. Among all these compounds, compound 5e, with an IC50 value of 1.288 μM is the most active against carbonic hCA I. Compound 5h with an IC50 value of 1.532 μM is the most active against carbonic hCA-II. Compounds 5a-5j were also evaluated for their cytotoxic effects on the L929 mouse fibroblast (normal) cell line. The compounds were also analyzed for their antioxidant capacity by TAS, FRAP, and DPPH activity. Enzyme inhibition kinetics showed all compounds 5a-5j to inhibit the enzyme by non-competitive. The most active compound 5e for hCA I and compound 5h for hCA-II were subjected to molecular docking, which revealed their binding interactions with the enzyme's active site, confirming the experimental findings.

Discovery of novel benzenesulfonamides incorporating 1,2,3-triazole scaffold as carbonic anhydrase I, II, IX, and XII inhibitors

Sulfonamides are among the most promising potential inhibitors for carbonic anhydrases (CAs), which are pharmaceutically relevant targets for treating several disease conditions. Herein, a series of benzenesulfonamides bearing 1,2,3-triazole moiety as inhibitors of human (h) α-CAs (hCAs) were designed using the tail approach. The design method combines a benzenesulfonamide moiety with a tail of oxime and a zinc-binding group on a 1,2,3-triazole scaffold. Among the synthesized derivatives, the naphthyl (6m, K_I of 68.6 nM, S_I of 10.3), and methyl (6a, K_I of 56.3 nM, S_I of 11.7) derivatives (over hCA IX) and propyl (6c, K_I of 95.6 nM, S_I of 2.7), and pentyl (6d, K_I of 51.1 nM, S_I of 6.6) derivatives (over hCA XII) displayed a noticeable selectivity for isoforms hCA I and II, respectively. Meanwhile, derivative 6e displayed a potent inhibitory effect versus the cytosolic isoform hCA I (K_I of 47.8 nM) and tumor-associated isoforms hCA IX and XII (K_Is of 195.9 and 116.9 nM, respectively) compared with the reference drug acetazolamide (AAZ, K_Is of 451.8, 437.2, and 338.9 nM, respectively). Derivative 6b showed higher potency (K_I of 33.2 nM) than AAZ (K_I of 327.3 nM) towards another cytosolic isoform hCA II. Nevertheless, substituting the lipophilic large naphthyl tail to the 1,2,3-triazole linked benzenesulfonamides (6a-n) raised inhibitory effect versus hCA I and XII and selectivity towards hCA I and II isoforms over hCA IX. Evaluation of the cytotoxic potential of the synthesized derivatives was conducted in L929, MCF-7, and Hep-3B cell lines. Several compounds in the series demonstrated significant antiproliferative activity and minimal cytotoxicity. In the molecular docking study, the sulfonamide moiety interacted with the zinc-ion and neatly fit into the hCAs active sites. The extension of the tail was found to participate in diverse hydrophilic and hydrophobic interactions with adjacent amino acids, ultimately influencing the effectiveness and specificity of the derivatives.

Comprehensive Metabolite Profiling of Cinnamon (Cinnamomum zeylanicum) Leaf Oil Using LC-HR/MS, GC/MS, and GC-FID: Determination of Antiglaucoma, Antioxidant, Anticholinergic, and Antidiabetic Profiles

In this study, for the first time, the antioxidant and antidiabetic properties of the essential oil from cinnamon (Cinnamomum zeylanicum) leaves were evaluated and investigated using various bioanalytical methods. In addition, the inhibitory effects of cinnamon oil on carbonic anhydrase II (hCA II), acetylcholinesterase (AChE), and α-amylase, which are associated with various metabolic diseases, were determined. Further, the phenolic contents of the essential oil were determined using LC-HRMS chromatography. Twenty-seven phenolic molecules were detected in cinnamon oil. Moreover, the amount and chemical profile of the essential oils present in cinnamon oil was determined using GC/MS and GC-FID analyses. (E)-cinnamaldehyde (72.98%), benzyl benzoate (4.01%), and trans-Cinnamyl acetate (3.36%) were the most common essential oils in cinnamon leaf oil. The radical scavenging activities of cinnamon oil were investigated using 1,1-diphenyl-2-picryl-hydrazil (DPPH^•), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), and (ABTS^•+) bioanalytical scavenging methods, which revealed its strong radical scavenging abilities (DPPH^•, IC₅₀: 4.78 μg/mL; and ABTS^•+, IC₅₀: 5.21 μg/mL). Similarly, the reducing capacities for iron (Fe³⁺), copper (Cu²⁺), and Fe³⁺-2,4,6-tri(2-pyridyl)-S-triazine (TPTZ) were investigated. Cinnamon oil also exhibited highly effective inhibition against hCA II (IC₅₀: 243.24 μg/mL), AChE (IC₅₀: 16.03 μg/mL), and α-amylase (IC₅₀: 7.54μg/mL). This multidisciplinary study will be useful and pave the way for further studies for the determination of antioxidant properties and enzyme inhibition profiles of medically and industrially important plants and their oils.

Osteoblast Viability of Liquid Smoke Rice Hull and Nanoparticles Form as Periodontitis Treatment

OBJECTIVE

 Rice husk liquid smoke nanoparticles have the potential to be developed as a drug because they have anti-inflammatory effects that can modulate the process of osteoblast stimulation through osteoblast stimulation by thorough small size and enter cells easily. The osteoblast is the key of alveolar regeneration in periodontitis treatment. This present study analyzed the differences of liquid smoke rice husk and nanoparticles of liquid smoke rice husk on osteoblast viability as periodontitis treatment MATERIALS AND METHODS:  The liquid smoke rice husk was obtained from the pyrolysis process. The nanoparticles were made with chitosan, maltodextrin, and difference of concentration of liquid smoke rice husk (such as 1, 2.5, 5, 7.5, 10, 12.5, 15, and 17.5%). The viability of osteoblast was analyzed by 2,5-diphenyl-2H-tetrazolium bromide (MTT) assay.

STATISTICAL ANALYSIS

The data were analyzed using independent t-test to analyze the differences between liquid smoke rice husk and nanoparticles of liquid smoke rice husk, the significant was set a p<0.05.

RESULT

 The nanoparticles of liquid smoke rice husk showed higher osteoblast viability compared liquid smoke rice husk. The nanoparticles' concentration of 5, 7.5, and 10% showed higher osteoblast viability compared liquid smoke rice husk (p = 0.002, 0.000, and 0.001, respectively).

CONCLUSION

 The nanoparticles of liquid smoke rice husk showed higher viability of osteoblast. This confirmed that the nanoparticles were able to reduce the toxicity in the higher concentration of liquid smoke of rice husk.

Biochemical, structural, and computational studies of a γ-carbonic anhydrase from the pathogenic bacterium Burkholderia pseudomallei

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Melioidosis is a severe disease caused Burkholderia pseudomallei.

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γ-carbonic anhydrases (γ-CAs) have been recently introduced as novel antibacterial drug targets.

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A new γ-CA from B. pseudomallei has been investigated by a multidisciplinary approach.

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Obtained results provide an important starting point for developing new anti-melioidosis drugs.

Melioidosis is a severe disease caused by the highly pathogenic gram-negative bacterium Burkholderia pseudomallei. Several studies have highlighted the broad resistance of this pathogen to many antibiotics and pointed out the pivotal importance of improving the pharmacological arsenal against it. Since γ-carbonic anhydrases (γ-CAs) have been recently introduced as potential and novel antibacterial drug targets, in this paper, we report a detailed characterization of BpsγCA, a γ-CA from B. pseudomallei by a multidisciplinary approach. In particular, the enzyme was recombinantly produced and biochemically characterized. Its catalytic activity at different pH values was measured, the crystal structure was determined and theoretical pKa calculations were carried out. Results provided a snapshot of the enzyme active site and dissected the role of residues involved in the catalytic mechanism and ligand recognition. These findings are an important starting point for developing new anti-melioidosis drugs targeting BpsγCA.

Unravelling the effects of complexation of transition metal ions on the hydroxylation of catechol over the whole pH region

Catechol pollutants (CATPs) serving as chelating agents could coordinate with many metal ions to form various CATPs-metal complexes. Little information is available on the effects of complexation of metal ions on CATPs degradation. This work presents a systematical study of •OH-mediated degradation of catechol and catechol-metal complexes over the whole pH range in advanced oxidation processes (AOPs). Results show that the pH-dependent complexation of metal ions (Zn²⁺, Cu²⁺, Ti⁴⁺ and Fe³⁺) promotes the deprotonation of catechol under neutral and even acidic conditions. The radical adduct formation (RAF) reactions are both thermodynamically and kinetically favorable for all dissociation and complexation species, and OH/O^- group-containing C positions are more vulnerable to •OH attack. The kinetic results show that the complexation of the four metal ions offers a wide pH range of effectiveness for catechol degradation. At pH 7, the apparent rate constant (k_app) values for different systems follow the order of catechol+Ti⁴⁺ ≈ catechol+Zn²⁺ > catechol+Cu²⁺ > catechol+Fe³⁺ > catechol. The mechanistic and kinetic results would greatly improve our understanding of the degradation of CATPs-metal and other organics-metal complexes in AOPs. The toxicity assessment indicates that the •OH-based AOPs have the ability for decreasing the toxicity and increasing the biodegradability during the processes of catechol degradation.

Efficient One-pot Synthesis of 3,3-di(indolyl)indolin-2-ones from Isatin and Indole Catalyzed by VOSO4 as Non-Sulfonamide Carbonic Anhydrase Inhibitors

Background A high yielding green protocol has been developed and delineated for the synthesis of 3,3-di(indolyl)indolin-2-ones, potentially bioactive compounds, involving one pot aqueous medium condensation of isatin with indole in the presence of VOSO4. The synthesized compounds were screened for their carbonic anhydrase inhibitory activity against human (h) isoforms hCA I, hCA II, hCA IX and hCA XII. These non-sulfonamide derivatives selectively inhibited hCA II in the micromolar range. Objective To develop a high yielding green protocol to synthesize 3,3-diindolyl oxindole derivatives using water as solvent media and screening of the synthesized molecules for their carbonic anhydrase inhibitory activity. Methods The target compound is obtained by taking isatin, indole, VOSO4and H2O in one-pot at 70 oC. Results The designed molecules were synthesized by using the new method. The molecules were screened for their CA inhibitory activity which shows selective inhibition toward hCA II.The result shown an excellent yield without any loss or decrease in catalytic activity, hence proved the performance and recyclability of the catalyst. Conclusion An efficient, simple and green protocol was established that provides a facile and straightforward approach for the preparation of 3,3-diindolyl oxindole derivatives (3a-r) from Isatin and Indole by using 10 mol % VOSO4 in high yields in a short period of time by a one-pot coupling reaction. Furthermore, the catalyst can also be recovered and reused for three consecutive catalytic cycle without any loss of its efficiency which was confirmed by performing the experiment with 3a. The newly synthesized molecules (3a-r) were screened for their carbonic anhydrase inhibition potency against four isoforms, hCA I, II, IX and XII and most of the compounds were found potent against hCA II with potency low to submicromolar range.

Inhibition Profiles of Some Symmetric Sulfamides Derived from Phenethylamines on Human Carbonic Anhydrase I, and II Isoenzymes

In this work, the inhibitory effect of some symmetric sulfamides derived from phenethylamines were determined against human carbonic anhydrase (hCA) I, and II isoenzymes, and compared with standard compound acetazolamide. IC₅₀ values were obtained from the Enzyme activity (%)-[Symmetric sulfamides] graphs. Also, K_i values were calculated from the Lineweaver-Burk graphs. Some symmetric sulfamides compounds (11-18) demonstrated excellent inhibition effects against hCA I, and II isoenzymes. These compounds demonstrated effective inhibitory profiles with IC₅₀ values in ranging from 21.66-28.88 nM against hCA I, 14.44-30.13 nM against hCA II. Among these compounds, the best K_i value for hCA I (K_i : 8.34±1.60 nM) and hCA II (K_i : 16.40±1.00 nM) is compound number 11. Besides, the IC₅₀ value of acetazolamide used as a standard was determined as hCA I, hCA II 57.75 nM, 49.50 nM, respectively. Moreover, in silico ADME-Tox study showed that all synthesized compounds (11-18) had good oral bioavailability in light of Jorgensen's rule of three, and of Lipinski's rule of five.

Novel Mannich bases with strong carbonic anhydrases and acetylcholinesterase inhibition effects: 3-(aminomethyl)-6-{3-[4-(trifluoromethyl)phenyl]acryloyl}-2(3H)-benzoxazolones

In this study, a new series of Mannich bases, 3-(aminomethyl)-6-{3-[4-(trifluoromethyl)phenyl]acryloyl}-2( 3H )-benzoxazolones ( 1a-g ), were synthesized by the Mannich reaction. Inhibitory effects of the newly synthesized compounds towards carbonic anhydrases (CAs) and acetylcholinesterase (AChE) enzymes were evaluated to find out new potential drug candidate compounds. According to the inhibitory activity results, Ki values of the compounds 1 and 1a-g were in the range of 12.3 ± 1.2 to 154.0 ± 9.3 nM against hCA I, and they were in the range of 8.6 ± 1.9 to 41.0 ± 5.5 nM against hCA II. Ki values of acetazolamide (AZA) that was used as a reference compound were 84.4 ± 8.4 nM towards hCA I and 59.2 ± 4.8 nM towards hCA II. Ki values of the compounds 1 and 1a-g were in the range of 35.2 ± 2.0 to 158.9 ± 33.5 nM towards AChE. Ki value of Tacrine (TAC), the reference compound, was 68.6 ± 3.8 nM towards AChE. Furthermore, docking studies were done with the most potent compounds 1d , 1g , and 1f (in terms of hCA I, hCA II, and AChE inhibition effects, respectively) to determine the binding profiles of the series with these enzymes. Additionally, the prediction of ADME profiles of the compounds pointed out that the newly synthesized compounds had desirable physicochemical properties as lead compounds for further studies.

Synthesis and biological evaluation of some 1-naphthol derivatives as antioxidants, acetylcholinesterase, and carbonic anhydrase inhibitors

A series of some naphthol derivatives 4a-f, 5a,f, 6a, and 7a,b (six novel ones: 4c,d, 5a, 6a, 7a,b) bearing F, Cl, Br, OMe, and dioxole substituents at different positions of the aromatic rings was designed, synthesized, and characterized. The naphthol derivatives were synthesized in three steps, namely the addition reaction of furan via Diels-Alder cycloaddition reaction, copper(II) trifluoromethanesulfonate (Cu(OTf)₂ )-catalyzed aromatization reaction, and the bromination reaction, respectively. The structures of the newly obtained compounds (4c,d, 5a, 6a, 7a,b) were characterized by spectroscopic techniques. In addition, some biological activity studies were investigated under in vitro conditions. Inhibition studies of these compounds were performed on human carbonic anhydrase (hCA) I and II isoenzymes purified from human erythrocytes as a biological evaluation. Moreover, their potential antioxidant and antiradical activities were studied by analytical methods like ABTS^•+ and DPPH• scavenging, and it was determined that some molecules showed good activity. Also, inhibition of acetylcholinesterase (AChE), which is a marker of many degenerative neurological diseases, was tested and the results were discussed. Excellent enzyme inhibition results were recorded for most of the molecules. These 1-naphthol derivatives were found as effective inhibitors for hCA I, hCA II, and AChE with K _i values ranging from 0.034 ± 0.54 to 0.724 ± 0.18 µM for hCA I, 0.172 ± 0.02 to 0.562 ± 0.21 µM for hCA II, and 0.096 ± 0.01 to 0.177 ± 0.02 µM for AChE.

Synthesis of novel tris-chalcones and determination of their inhibition profiles against some metabolic enzymes

In this study, we report the synthesis of novel tris-chalcones and testing of human carbonic anhydrase I, and II isoenzymes (hCA I, and hCA II), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α-glycosidase (α-Gly) inhibitors for the development of novel chalcone structures towards for treatment of some diseases. The compounds demonstrated K_i values between 13.6 ± 1.1 and 50.0 ± 17.1 nM on hCA I, 9.9 ± 0.8 and 39.5 ± 15.1 nM on hCA II, 3.1 ± 0.2 and 20.1 ± 1.9 nM on AChE, 4.9 ± 0.4 and 14.7 ± 5.2 nM on BChE and 3.9 ± 0.2 and 22.4 ± 10.7 nM on α-Gly enzymes. The results revealed that novel tris-chalcones can have promising drug potential for glaucoma, leukaemia, epilepsy; Alzheimer's disease that was associated with the high enzymatic activity of hCA I, hCA II, AChE, and BChE enzymes.

Utilization of the zebrafish model to unravel the harmful effects of biomass burning during Amazonian wildfires

Amazonian wildfires in 2019 have raised awareness about rainforest burning due to increased emissions of particulate matter and carbon. In the context of these emissions, by-products of lignin thermal degradation (i.e. methoxyphenols) are often neglected. Methoxyphenols entering the atmosphere may form intermediates with currently unknown reaction mechanisms and toxicity. This study for the first time provides a comprehensive insight into the impact of lignin degradation products [guaiacol, catechol], and their nitrated intermediates [4-nitrocatechol, 4,6-dinitroguaiacol, 5-nitroguaiacol] on zebrafish Danio rerio. Results revealed 4-nitrocatechol and catechol as the most toxic, followed by 4,6DNG > 5NG > GUA. The whole-organism bioassay integrated with molecular modeling emphasized the potential of methoxyphenols to inhibit tyrosinase, lipoxygenase, and carbonic anhydrase, consequently altering embryonic development (i.e. affected sensorial, skeletal, and physiological parameters, pigmentation formation failure, and non-hatching of larvae). The whole-organism bioassay integrated with in silico approach confirmed the harmful effects of lignin degradation products and their intermediates on aquatic organisms, emphasizing the need for their evaluation within ecotoxicity studies focused on aquatic compartments.

Preparation, carbonic anhydrase enzyme inhibition and antioxidant activity of novel 7-amino-3,4-dihydroquinolin-2(1H)-one derivatives incorporating mono or dipeptide moiety

New dipeptide–dihydroquinolinone derivatives were successfully synthesised by benzotriazole mediated nucleophilic acyl substitution reaction and their structures were elucidated by spectroscopic and analytic techniques. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory activity of the new compounds was determined against four human (h) isoforms, hCA I, hCA II, hCA IX and hCA XII. While all compounds showed moderate to good in vitro CA inhibitory properties against hCA IX and hCA XII with inhibition constants in the micromolar level (37.7–86.8 and 2.0–8.6 µM, respectively), they did not show inhibitory activity against hCA I and hCA II up to 100 µM concentration. The antioxidant capacity of the peptide–dihydroquinolinone conjugates was determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. Most of the synthesised compounds showed low antioxidant activities compared to the control antioxidant compounds BHA and α-tocopherol.

Synthesis and in silico studies of triazene-substituted sulfamerazine derivatives as acetylcholinesterase and carbonic anhydrases inhibitors

A novel series of sulfonamides, 4-(3-phenyltriaz-1-en-1-yl)-N-(4-methyl-2-pyrimidinyl)benzenesulfonamides (1-9), was designed and synthesized by the diazo reaction between sulfamerazine and substituted aromatic amines for the first time. Their chemical structures were characterized by ¹ H nuclear magnetic resonance (NMR), ¹³ C NMR, and high-resolution mass spectra. The newly synthesized compounds were evaluated in terms of acetylcholineasterase (AChE) and human carbonic anhydrases (hCA) I and II isoenzymes inhibitory activities. According to the AChE inhibition results, the K_i values of the compounds 1-9 were in the range of 19.9 ± 1.5 to 96.5 ± 20.7 nM against AChE. Tacrine was used as the reference drug and its K_i value was 49.2 ± 2.7 nM against AChE. The K_i values of the compounds 1-9 were in the range of 10.2 ± 2.6 to 101.4 ± 27.8 nM against hCA I, whereas they were 18.3 ± 4.4 to 48.1 ± 4.5 nM against hCA II. Acetazolamide was used as a reference drug and its K_i values were 72.2 ± 5.4 and 52.2 ± 5.7 nM against hCA I and hCA II, respectively. The most active compounds, 1 (nonsubstituted) against AChE, 5 (4-ethoxy-substituted) against hCA I, and 8 (4-bromo-substituted) against hCA II, were chosen and docked at the binding sites of these enzymes to explain the inhibitory activities of the series. The newly synthesized compounds presented satisfactory pharmacokinetic properties via the estimation of ADME properties.

Synthesis of nitrogen, phosphorus, selenium and sulfur-containing heterocyclic compounds - Determination of their carbonic anhydrase, acetylcholinesterase, butyrylcholinesterase and α-glycosidase inhibition properties

Sulfur-containing pyrroles (1-3), tris(2-pyridyl)phosphine(selenide) sulfide (4-5) and 4-benzyl-6-(thiophen-2-yl)pyrimidin-2-amine (6) were synthesized and characterized by elemental analysis, IR and NMR spectra. In this study, the synthesized compounds of nitrogen, phosphorus, selenium and sulfur-containing heterocyclic compounds (1-6) were evaluated against the human erythrocyte carbonic anhydrase I, and II isoenzymes, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α-glycosidase enzymes. The synthesized heterocyclic compounds showed IC₅₀ values in range of 33.32-60.79 nM against hCA I, and 37.05-66.64 nM against hCA II closely associated with various physiological and pathological processes. On the other hand, IC₅₀ values were found in range of 13.13-22.21 nM against AChE, 0.54-31.22 nM against BChE, and 13.51-26.55 nM against α-glycosidase as a hydrolytic enzyme. As a result, nitrogen, phosphorus, selenium and sulfur-containing heterocyclic compounds (1-6) demonstrated potent inhibition profiles against indicated metabolic enzymes. Therefore, we believe that these results may contribute to the development of new drugs particularly in the treatment of some global disorders including glaucoma, Alzheimer's disease and diabetes.

In Silico Identification and Biological Evaluation of Antioxidant Food Components Endowed with IX and XII hCA Inhibition

The tumor-associated isoenzymes hCA IX and hCA XII catalyze the hydration of carbon dioxide to bicarbonate and protons. These isoforms are highly overexpressed in many types of cancer, where they contribute to the acidification of the tumor environment, promoting tumor cell invasion and metastasis. In this work, in order to identify novel dual hCA IX and XII inhibitors, virtual screening techniques and biological assays were combined. A structure-based virtual screening towards hCA IX and XII was performed using a database of approximately 26,000 natural compounds. The best shared hits were submitted to a thermodynamic analysis and three promising best hits were identified and evaluated in terms of their hCA IX and XII inhibitor activity. In vitro biological assays were in line with the theoretical studies and revealed that syringin, lithospermic acid, and (-)-dehydrodiconiferyl alcohol behave as good hCA IX and hCA XII dual inhibitors.

Synthesis and bioactivities of 1-(4-hydroxyphenyl)-2-((heteroaryl)thio)ethanones as carbonic anhydrase I, II and acetylcholinesterase inhibitors

The discovery of enzyme targeting inhibitors is a popular area of drug research. Biological activities of the compounds bearing phenol and heteroaryl groups make them popular groups in drug design targeting important enzymes such as acetylcholinesterase (AChE, E.C.3.1.1.7) and carbonic anhydrases (CAs, EC 4.2.1.1). 1-(4-hydroxyphenyl)- 2-((aryl)thio)ethanones as possible AChE and CAs inhibitors were synthesized, and their chemical structures were confirmed by IR, 1H NMR, 13C NMR, and HRMS. The compounds 2 and 4 were found potent AChE inhibitors with the Ki values of 22.13 ±1.96 nM and 23.71 ±2.95 nM, respectively, while the compounds 2 (Ki = 8.61 ±0.90 nM, on hCA I) and 1 (Ki = 8.76 ±0.84 nM, on hCA II) had considerable CAs inhibitory potency. The lead compounds may help the scientists for the rational designing of an innovative class of drug candidates targeting enzyme-based diseases.

Synthesis and human carbonic anhydrase I, II, VA, and XII inhibition with novel amino acid-sulphonamide conjugates

A series of amino acid-sulphonamide conjugates was prepared through benzotriazole mediated coupling reactions and characterised by ¹H-NMR, ¹³C-NMR, MS, and FTIR spectroscopic techniques as well as elemental analysis. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory activity of the new compounds was determined against four human (h) isoforms, hCA I, hCA II, hCA VA, and hCA XII. Most of the synthesised compounds showed effective in vitro CA inhibitory properties. The new amino acid-sulphonamide conjugates showed potent inhibitory activity against hCA II, some of them at subnanomolar levels, exhibiting more effective inhibitory activity compared to the standard drug acetazolamide. Some of these sulphonamides were also found to be effective inhibitors of hCA I, hCA VA, and hCA XII, with activity from the low to high nanomolar range.

Design, synthesis, characterization of peripherally tetra-pyridine-triazole-substituted phthalocyanines and their inhibitory effects on cholinesterases (AChE/BChE) and carbonic anhydrases (hCA I, II and IX)

In this study, phthalocyanine precursors (5and9) and 1,2,3-triazole-substituted metal-free and metallo phthalocyanines (9a–c) were designed and synthesized for the first time and evaluatedin vitrofor key molecular targets.

Synthesis carbonic anhydrase enzyme inhibition and antioxidant activity of novel benzothiazole derivatives incorporating glycine, methionine, alanine, and phenylalanine moieties

Thirteen novel benzothiazole derivatives incorporating glycine, methionine, alanine, and phenylalanine were synthesised by facile acylation reactions through benzotriazole or DCC mediated reactions and their structures were identified by 1H-NMR, 13C-NMR, and FT-IR spectroscopic techniques and elemental analysis. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory activity of the new compounds was assessed against four human (h) isoforms, hCA I, hCA II, hCA V, and hCA XIII. Some of the synthesised compounds showed good in vitro carbonic anhydrase inhibitory properties, with inhibition constants in the micromolar level. The new amino acid benzothiazole conjugates found to be more effective against hCA V and hCA II inhibition. In vitro antioxidant activities of the novel compounds were determined by DPPH method. Most of the synthesised compounds showed moderate to low antioxidant activities compared to the control antioxidant compounds (BHA and α-tocopherol).

Hydroxyl substituted benzoic acid/cinnamic acid derivatives: Tyrosinase inhibitory kinetics, anti-melanogenic activity and molecular docking studies

The inhibition of tyrosinase is an established strategy for treating hyperpigmentation. Our previous findings demonstrated that cinnamic acid and benzoic acid scaffolds can be effective tyrosinase inhibitors with low toxicity. The hydroxyl substituted benzoic and cinnamic acid moieties of these precursors were incorporated into new chemotypes that displayed in vitro inhibitory effect against mushroom tyrosinase. The most active compound, (2-(3-methoxyphenoxy)-2-oxoethyl (E)-3-(4-hydroxyphenyl) acrylate) 6c, inhibited tyrosinase with an IC₅₀ of 5.7 µM, while (2-(3-methoxyphenoxy)-2-oxoethyl 2, 4-dihydroxybenzoate) 4d had an IC₅₀ of 23.8 µM. In comparison, the positive control, kojic acid showed tyrosinase inhibition with an IC₅₀ = 16.7 µM. Analysis of enzyme kinetics revealed that 6c and 4d displayed noncompetitive reversible inhibition of the second tyrosinase enzymatic reaction with K_i values of 11 µM and 130 µM respectively. In silico docking studies with mushroom tyrosinase (PDB ID 2Y9X) predicted possible binding modes in the catalytic site for these active compounds. The phenolic para-hydroxy group of the most active compound 6c is predicted to interact with the catalytic site Cu⁺⁺ ion. The methoxy part of this compound is predicted to form a hydrogen bond with Arg 268. Compound 6c had no observable toxic effects on cell morphology or cell viability at the highest tested concentration of 91.4 µM. When dosed at 91.4 µM onto B16F10 melanoma cells in vitro6c showed anti-melanogenic effects equivalent to kojic acid at 880 µM. 6c displayed no PAINS (pan-assay interference compounds) alerts. Our results show that compound 6c is a more potent tyrosinase inhibitor than kojic acid and is a candidate for further development. Our exposition of the details of the interactions between 6c and the catalytic pocket of tyrosinase provides a basis for rational design of additional potent inhibitors of tyrosinase, built on the cinnamic acid scaffold.

Potential of Distilled Liquid Smoke Derived from Coconut (Cocos nucifera L) Shell for Traumatic Ulcer Healing in Diabetic Rats

Objective Distilled liquid smoke (DLS) is a result of coconut processing by-product that not only serves as a natural food preservative but also has a promising therapeutic effect. The healing potential of DLS derived from coconut ( Cocos nucifera L) shell was investigated on a traumatic ulcer with the diabetic rat.

Materials and Methods DLS was analyzed the component by gas chromatograph mass spectrometry. Diabetic condition was induced by alloxan in 55 male Wistar rats. Ten mm of traumatic ulcer was made along the labial fornix incisive inferior after the diabetic condition was confirmed. Then DLS coconut shell, benzydamine hydrochloride, and sterile distilled water were applied topically for 3, 5, and 7 days. The potential healing was evaluated based on the expression of nuclear factor kappa beta (NFκB) and tumor necrosis factor alpha (TNF-α) on macrophages using immunohistochemical staining and the amount of collagen using Masson Trichome staining. The difference between each group was analyzed using one-way analysis of variance. The least significant difference test is used to determine the significant difference ( p < 0.05).

Results The major compounds found were phenol (36.6%), 2-methoxyphenol (guaiacol) (25.2%), furfural (17.8%), and 4-ethyl-2-methoxyphenol (3.5%) with 28 other minor constituents. The lowest NFκB and TNF-α expression on macrophage was observed by topical application of DLS derived from coconut shell for 3, 5, and 7 days of treatment. The amount of collagen was increased and indicated by the highest result of DLS compared to others.

Conclusion The DLS derived from coconut ( Cocos nucifera L) shell was able to improve traumatic ulcer healing in a person with diabetes.

Synthesis of oxazolidinone from enantiomerically enriched allylic alcohols and determination of their molecular docking and biologic activities

Enantioselective synthesis of functionalized cyclic allylic alcohols via kinetic resolution in transesterifcation with different lipase enzymes has been developed. The influence of the enzymes and temperature activity was studied. By determination of ideal reaction conditions, byproduct formation is minimized; this made it possible to prepare enantiomerically enriched allylic alcohols in high ee's and good yields. Enantiomerically enriched allylic alcohols were used for enantiomerically enriched oxazolidinone synthesis. Using benzoate as a leaving group means that 1 mol % of potassium osmate is necessary and can be obtained high yields 98%. Inhibitory activities of enantiomerically enriched oxazolidinones (8, 10 and 12) were tested against human carbonic anhydrase I and II isoenzymes (hCA I and hCA II), acetylcholinesterase (AChE), and α-glycosidase (α-Gly) enzymes. These enantiomerically enriched oxazolidinones derivatives had K_i values in the range of 11.6 ± 2.1-66.4 ± 22.7 nM for hCA I, 34.1 ± 6.7-45.2 ± 12.9 nM for hCA II, 16.5 ± 2.9 to 35.6 ± 13.9 for AChE, and 22.3 ± 6.0-70.9 ± 9.9 nM for α-glycosidase enzyme. Moreover, they had high binding affinity with -5.767, -6.568, -9.014, and -8.563 kcal/mol for hCA I, hCA II, AChE and α-glycosidase enzyme, respectively. These results strongly supported the promising nature of the enantiomerically enriched oxazolidinones as selective hCA, AChE, and α-glycosidase inhibitors. Overall, due to these derivatives' inhibitory potential on the tested enzymes, they are promising drug candidates for the treatment of diseases like glaucoma, leukemia, epilepsy; Alzheimer's disease; type-2 diabetes mellitus that are associated with high enzymatic activity of CA, AChE, and α-glycosidase.

Inhibition of carbonic anhydrase IX targets primary tumors, metastases, and cancer stem cells: Three for the price of one

Human carbonic anhydrase (CA) IX is a tumor-associated protein, since it is scarcely present in normal tissues, but highly overexpressed in a large number of solid tumors, where it actively contributes to survival and metastatic spread of tumor cells. Due to these features, the characterization of its biochemical, structural, and functional features for drug design purposes has been extensively carried out, with consequent development of several highly selective small molecule inhibitors and monoclonal antibodies to be used for different purposes. Aim of this review is to provide a comprehensive state-of-the-art of studies performed on this enzyme, regarding structural, functional, and biomedical aspects, as well as the development of molecules with diagnostic and therapeutic applications for cancer treatment. A brief description of additional pharmacologic applications for CA IX inhibition in other diseases, such as arthritis and ischemia, is also provided.

Synthesis of N'-phenyl-N-hydroxyureas and investigation of their inhibitory activities on human carbonic anhydrases

A series of N'-phenyl-N-hydroxyureas has been prepared by reacting hydroxylamine with aromatic isocyanates. These compounds were investigated as inhibitors of human carbonic anhydrases (hCAs, EC 4.2.1.1), considering four physiologically relevant isoforms, the cytosolic isoforms hCA I and II, and tumor associated, transmembrane isoforms hCA IX and XII. The new compounds reported here did not inhibit the widespread cytosolic isoforms hCA I and II, but they inhibited the tumor associated isoforms with interesting potencies. The most effective inhibitors showed K_Is ranging between 72.8 and 78.9 nM against hCA IX and between 6.9 and 7.2 against hCA XII, making them of interest as candidates for antitumor studies.