Synthesis and carbonic anhydrase inhibitory properties of novel cyclohexanonyl bromophenol derivatives

Efficient, rapid, and high-yield synthesis of aryl Schiff base derivatives and their in vitro and in silico inhibition studies of hCA I, hCA II, AChE, and BuChE

This study reports a rapid and efficient synthesis of four novel aryl Schiff base derivatives. Biological activity and molecular modeling studies were conducted to evaluate the inhibitory effects of these compounds on human carbonic anhydrases (hCA) and cholinesterases. The results indicate that the triazole-ring-containing compounds have strong inhibitory effects on hCA I, hCA II, acetylcholinesterase (AChE), and butyrylcholinesterase (BuChE) targets. Besides comparing the Schiff bases synthesized in our study to reference molecules, we conducted in silico investigations to examine how these compounds interact with their targets. Our studies revealed that these compounds can occupy binding sites and establish interactions with crucial residues, thus inhibiting the functions of the targets. These findings have significant implications as they can be utilized to develop more potent compounds for treating the diseases that these target proteins play crucial roles in or to obtain drug precursors with enhanced efficacy.

Asymmetric α-benzylation of cyclic ketones enabled by concurrent chemical aldol condensation and biocatalytic reduction

Chemoenzymatic cascade catalysis has emerged as a revolutionary tool for streamlining traditional retrosynthetic disconnections, creating new possibilities for the asymmetric synthesis of valuable chiral compounds. Here we construct a one-pot concurrent chemoenzymatic cascade by integrating organobismuth-catalyzed aldol condensation with ene-reductase (ER)-catalyzed enantioselective reduction, enabling the formal asymmetric α-benzylation of cyclic ketones. To achieve this, we develop a pair of enantiocomplementary ERs capable of reducing α-arylidene cyclic ketones, lactams, and lactones. Our engineered mutants exhibit significantly higher activity, up to 37-fold, and broader substrate specificity compared to the parent enzyme. The key to success is due to the well-tuned hydride attack distance/angle and, more importantly, to the synergistic proton-delivery triade of Tyr28-Tyr69-Tyr169. Molecular docking and density functional theory (DFT) studies provide important insights into the bioreduction mechanisms. Furthermore, we demonstrate the synthetic utility of the best mutants in the asymmetric synthesis of several key chiral synthons.

Synthesis and biological evaluation of novel salicylidene uracils: Cytotoxic activity on human cancer cell lines and inhibitory action on enzymatic activity

A series of salicylidene uracil (1-18) derived from 5-aminouracil and substituted salicylaldehydes were analyzed for cytotoxic activity and enzyme inhibitory potency. Nine out of eighteen derivatives (6-8, 10, 12-15, 18) are novel molecules synthesized for the first time in this work, and other derivatives were previously synthesized by our group. The compounds were characterized by Proton nuclear magnetic resonance, carbon nuclear magnetic resonance, fourier transform infrared spectroscopy, and elemental analysis. All compounds were tested for their in vitro cytotoxicity against PC-3 (human prostate adenocarcinoma), A549 (human alveolar adenocarcinoma), and SHSY-5Y (human neuroblastoma) cancer cell lines and the nontumorigenic HEK293 (human embryonic kidney cells) cell line. The 3,5-di-tert-butylsalicylaldehyde derived compound (8) was toxic to PC-3 human prostate adenocarcinoma cells, showing a promising IC50 value at 7.05 ± 0.76 μM. The present study also aimed to evaluate the inhibitory effects of the compounds against several key enzymes, namely carbonic anhydrase I and II (CA I and CA II), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and glutathione reductase (GR), which are implicated in various global disorders, such as Alzheimer's disease, epilepsy, cancer, malaria, diabetes, and glaucoma. The inhibitory profiles of the tested compounds were assessed by determining their Ki values, which ranged from 2.96 to 9.24 nM for AChE, 3.78 to 12.57 nM for BChE, 8.42 to 25.74 nM for CA I, 7.24 to 19.74 nM for CA II, and 0.541 to 1.124 μM for GR. Molecular docking studies were also performed for all compounds. Most derivatives exhibited much more effective inhibitory action compared with clinically used standards. Thus, our findings indicate that the salicylidene derivatives presented in this study are promising drug candidates that need further evaluation.

Synthesis and Biological Activity of Some Bromophenols and Their Derivatives Including Natural Products

In addition to the first synthesis of the natural bromophenol butyl 2-(3,5-dibromo-4-hydroxyphenyl)acetate (1), indene derivatives 34 and 35 were synthesized from 3-phenylpropenal derivatives in BBr3 medium. Five known natural bromophenols and some derivatives were synthesized by known methods. Cholinesterase (ChEs) inhibitors reduce the breakdown of acetylcholine and are used in the treatment of Alzheimer's disease (AD) and dementia symptoms. The inhibition effects of all obtained compounds were examined towards acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and α-glycosidase enzymes. All synthesized compounds demonstrated the strong inhibition effects against both cholinergic enzymes. For determination of Ki values of novel bromophenols Lineweaver-Burk graphs were obtained. Ki values were found in the ranging of 0.13-14.74 nM for AChE, 5.11-23.95 nM for BChE, and 63.96-206.78 nM for α-glycosidase, respectively. All bromophenols and their derivatives exhibit effective inhibition profile when compared to positive controls.

Naturally Occurring Organohalogen Compounds-A Comprehensive Review

The present volume is the third in a trilogy that documents naturally occurring organohalogen compounds, bringing the total number-from fewer than 25 in 1968-to approximately 8000 compounds to date. Nearly all of these natural products contain chlorine or bromine, with a few containing iodine and, fewer still, fluorine. Produced by ubiquitous marine (algae, sponges, corals, bryozoa, nudibranchs, fungi, bacteria) and terrestrial organisms (plants, fungi, bacteria, insects, higher animals) and universal abiotic processes (volcanos, forest fires, geothermal events), organohalogens pervade the global ecosystem. Newly identified extraterrestrial sources are also documented. In addition to chemical structures, biological activity, biohalogenation, biodegradation, natural function, and future outlook are presented.

Carbonic Anhydrase Inhibitors from Marine Natural Products

Carbonic anhydrases (CAs, EC 4.2.1.1) are widespread metalloenzymes in organisms in all life kingdoms, being involved in pH regulation, metabolic processes and many other physiological and pathological conditions. CA inhibitors and activators thus possess applications as pharmacological agents in the management of a range of diseases. Marine natural products have allowed the identification of some highly interesting CA inhibitors, among which are sulfonamides, phenols, polyamines, coumarins and several other miscellaneous inhibitors, which are reviewed here. Psammaplin C and some bromophenols were the most investigated classes of such marine-based inhibitors and have been used as lead molecules for developing interesting types of potent and, in some cases, isoform-selective inhibitors, with applications as antitumor agents by inhibiting human CA XII and P-glycoprotein activities. Some phenols have shown interesting bacterial and fungal β-CA inhibitory effects. Marine natural products thus constitute a gold mine for identifying novel CA inhibitors, some of which may lead to the development of novel types of pharmacological agents.

Synthesis and aldose reductase inhibition effects of celecoxib derivatives containing pyrazole linked-sulfonamide moiety

In this article, we report the synthesis of Celecoxib derivatives containing the pyrazole-linked sulfonamide moiety. The enzyme inhibition effects of these derivatives on aldose reductase (AR) were also investigated. The IC₅₀ values of the pyrazole sulfonamide derivatives were determined to be in the range of 40.76-8.25 µM. Among the synthesized derivatives, the compound 16 showed the strongest inhibition effect against the AR enzyme, with an IC₅₀ value of 8.25 µM. Molecular docking studies were carried out to determine the interactions of the synthesized compounds with the AR enzyme, and ADMET studies were performed to assess the pharmacokinetic and drug-likeness properties.

Synthesis, characterization, and biological evaluation of some novel Schiff bases as potential metabolic enzyme inhibitors

In this study, a series of novel Schiff base derivatives containing a pyrazolone ring (2a-e) were designed, successfully synthesized for the first time, and characterized by elemental analysis and some spectroscopic methods. These compounds were tested for their inhibitory activities on acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and the human carbonic anhydrase isoenzymes I and II (hCA I and II). All synthesized molecules indicated significant inhibition effects with IC₅₀ values ranging from 14.15 to 107.62 nM against these enzymes. Compound 2d showed the most potent inhibitory activity among the tested molecules toward AChE and BChE (IC₅₀  = 15.07 and 14.15 nM) compared to the standard drug neostigmine. We determined that the IC₅₀ values of the tested molecules ranged between 16.86 and 57.96 nM for hCA I and 15.24-46.21 nM for hCA II. As a consequence, we may say that some of the Schiff base derivatives may be used as potential drug candidates in later studies.

Synthesis and Aldose Reductase Inhibition Effects of Novel N-Benzyl-4-Methoxyaniline Derivatives

In the current study, starting from 4-methoxyaniline, four Schiff bases were synthesized from benzaldehydes with Br and OMe. Corresponding N-benzylanilines and their derivatives were obtained from reductions (by NaBH₄ ) and substitutions (by acyl and tosyl chlorides) of these bases, respectively. The inhibitory effects of the sixteen compounds, twelve of which were novel compounds are examined. Then, we conducted molecular docking and binary QSAR studies to determine inhibitory-enzyme interactions of compounds that show an inhibitory effect. Our results reveal that methoxyanilline-derived compounds show good biological activities. The most active compound (22) has IC₅₀ values of 2.83 μM. These novel AR enzyme inhibitors may open new avenues for better AR inhibitors in the future.

Synthesis and some enzyme inhibition effects of isoxazoline and pyrazoline derivatives including benzonorbornene unit

Four new and four known isoxazoline derivatives were synthesized from the reactions of benzonorbornadiene with nitrile oxides formed from the corresponding benzaldehydes. Three new and one known pyrazoline derivatives were also synthesized from the reactions of the benzonorbornadiene with nitrile imines formed from the corresponding compounds. The synthesized nitrogen-based novel heterocyclic compounds were evaluated against the human carbonic anhydrase isoenzymes I and II (hCA I and hCA II), acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) enzymes. The synthesized nitrogen-based novel heterocyclic compounds showed IC₅₀ values in the range of 2.69-7.01 against hCA I, 2.40-4.59 against hCA II, 0.81-1.32 µM against AChE, and 20.83-1.70 µM against BChE enzymes. On the contrary, nitrogen-based novel heterocyclic compounds demonstrated K_i values between 2.93 ± 0.59-8.61 ± 1.39 against hCA I, 2.05 ± 0.62-4.97 ± 0.95 against hCA II, 0.34 ± 0.02-0.92 ± 0.17 nM against AChE, and 0.50 ± 0.04-1.20 ± 0.16 µM against BChE enzymes. The synthesized nitrogen-based novel heterocyclic compounds exhibited effective inhibition profiles against both indicated metabolic enzymes. These results may contribute to the development of new drugs particularly to treat some disorders, which are widespread in the world including glaucoma and Alzheimer's diseases.

A novel class for carbonic anhydrases inhibitors and evaluation of their non-zinc binding

In this study, 23 different imidazole derivatives were synthesized, and the inhibitory properties of these derivatives against carbonic anhydrase I and II isoenzymes were investigated for the first time. The inhibition concentrations of the imidazole derivatives were found to be in the range of 2.89-115.5 nM. Docking studies examined the binding properties of the imidazole derivatives, and the structure-activity relationship is discussed. Theoretical calculations showed that the binding mode of the imidazole ring was non-zinc binding.

Design, synthesis and molecular modelling studies of some pyrazole derivatives as carbonic anhydrase inhibitors

In this study, newly synthesised compounds 6, 8, 10 and other compounds (1-5, 7 and 9) and their inhibitory properties against the human isoforms hCA I and hCA II were reported for the first time. Compounds 1-10 showed effective inhibition profiles with KI values in the range of 5.13-16.9 nM for hCA I and of 11.77-67.39 nM against hCA II, respectively. Molecular docking studies were also performed with Glide XP to get insight into the inhibitory activity and to evaluate the binding modes of the synthesised compounds to hCA I and II. More rigorous binding energy calculations using MM-GBSA protocol which agreed well with observed activities were then performed to improve the docking scores. Results of in silico calculations showed that all compounds obey drug likeness properties. The new compounds reported here might be promising lead compounds for the development of new potent inhibitors as alternatives to classical hCA inhibitors.

Synthesis of N-phenylsulfonamide derivatives and investigation of some esterase enzymes inhibiting properties

In this study, synthesis of nine N-phenylsulfonamide derivatives was designed by starting from aniline, which is the simplest aromatic amine. These compounds were obtained in yields between 69 and 95%. Inhibitory properties of synthesized compounds on carbonic anhydrase I (CA I), CA II isoenzymes, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes were investigated. Inhibitors of CA isoenzymes are important therapeutic targets, particularly due to their preventive/activation potential in the treatment of diseases such as edema, glaucoma, cancer and osteoporosis. Cholinesterase inhibitors are valuable compounds that can be used in many different therapeutic applications, including Alzheimer's disease. The compound 8 for CA I, AChE and BChE, 2 for CA II showed a very active inhibition profile (K_I 45.7 ± 0.46 for CA I, 33.5 ± 0.38 nM for CA II, 31.5 ± 0.33 nM for AChE and 24.4 ± 0.29 nM for BChE). The results indicate that these N-phenyl-sulfonamide derivatives are potent CA and cholinesterases and new potential drugs.

Progress of Bromophenols in Marine Algae from 2011 to 2020: Structure, Bioactivities, and Applications

Marine algae contain various bromophenols that have been shown to possess a variety of biological activities, including antiradical, antimicrobial, anticancer, antidiabetic, anti-inflammatory effects, and so on. Here, we briefly review the recent progress of these marine algae biomaterials and their derivatives from 2011 to 2020, with respect to structure, bioactivities, and their potential application as pharmaceuticals.

Synthesis and antioxidant activities of phenol derivatives from 1,6-bis(dimethoxyphenyl)hexane-1,6-dione

Starting from the compound (3,4-dimethoxyphenyl)(2-(3,4-dimethoxyphenyl)cyclopent-1-en-1-yl)methanone (4), two diols and three tetrol derivatives were synthesised. Morover, from the reactions of 1,3-dimethoxybenzene and 1,4-dimethoxybenzene with adipoyl chloride, fifteen new along with nine known compounds were obtained. For the characterizations of compounds, spectroscopic methods such as NMR including DEPT, COSY, HMQC and HMBC experiments and X-ray diffraction were used. The antioxidant activities of novel synthesized seventeen molecules were investigated by analytical methods like ABTS^•+ and DPPH^• scavenging. Also, reducing power these molecules were investigated by Fe³⁺, Cu²⁺, and [Fe³⁺-(TPTZ)₂]³⁺. Some of the molecules record powerful antioxidant profile when compared to putative standards. The inhibition effects of the phenols compounds against AChE and BChE activities were analysed. Also, these phenols were found as effective inhibitors for AChE, hCA I, hCA II, and BChE with K_is in the range of 122.95 ± 18.41-351.31 ± 69.12 nM for hCA I, 62.35 ± 9.03-363.17 ± 180.1 nM for hCA II, 134.57 ± 3.99-457.43 ± 220.10 nM for AChE, and 27.06 ± 9.12-72.98 ± 9.53 nM for BChE, respectively.

Rhodium-catalyzed asymmetric hydrogenation of exocyclic α,β-unsaturated carbonyl compounds

A highly enantioselective hydrogenation of exocyclic α,β-unsaturated carbonyl compounds catalyzed by Rh/bisphosphine-thiourea (ZhaoPhos) has been developed, giving the corresponding α-chiral cyclic lactones, lactams and ketones with high yields and excellent enantioselectivities (up to 99% yield and 99% ee). Remarkably, the hydrogen bond between the substrate and the catalyst plays a critical role in this transformation. The synthetic utility of this protocol has been demonstrated by efficient synthesis of chiral 3-(4-fluorobenzyl)piperidine, a key chiral fragment of bioactive molecules.

Synthesis and biological evaluation of bromophenol derivatives with cyclopropyl moiety: Ring opening of cyclopropane with monoester

Trans-(1R*,2R*,3R*)-Ethyl 2-(3,4-dimethoxyphenyl)-3-methylcyclopropane-1-carboxylate (6) and its cis isomer 7 were obtained from the reaction of the methyl isoeugenol (5) with ethyl diazoacetate. The reduction and bromination reactions of the ester 6 and 7 together with the hydrolysis of all esters were carried out. Opening ring of cyclopropane was observed in the reaction of 7 with bromine. The opening of cyclopropane ring with COOR and synthesis of esters, alcohols and acids (6-26) are new. These obtained bromophenol derivatives (6-26) were effective inhibitors of the cytosolic carbonic anhydrase I and II isoforms (hCA I and II) and acetylcholinesterase (AChE) enzymes with Ki values in the range of 7.8 ± 0.9-58.3 ± 10.3 nM for hCA I, 43.1 ± 16.7-150.2 ± 24.1 nM for hCA II, and 159.6 ± 21.9-924.2 ± 104.8 nM for AChE, respectively. Acetylcholinesterase inhibitors are the most popular drugs applied in the treatment of diseases such as Alzheimer's disease, Parkinson's disease, senile dementia, and ataxia, among others.

Intrinsic thermodynamics of high affinity inhibitor binding to recombinant human carbonic anhydrase IV

Membrane-associated carbonic anhydrase (CA) isoform IV participates in carbon metabolism and pH homeostasis and is implicated in the development of eye diseases such as retinitis pigmentosa and glaucoma. A series of substituted benzenesulfonamides were designed and their binding affinity to CA IV was determined by fluorescent thermal shift assay and isothermal titration calorimetry (ITC). Compound [(4-chloro-2-phenylsulfanyl-5-sulfamoyl-benzoyl)amino]propyl acetate (19) bound CA IV with the K _d of 1.0 nM and exhibited significant selectivity over the remaining 11 human CA isoforms. The compound could be developed as a drug targeting CA IV. Various forms of recombinant CA IV were produced in Escherichia coli and mammalian cell cultures. Comparison of their temperature stability in various buffers and salt solutions demonstrated that CA IV is most stable at slightly alkaline conditions and at elevated sodium sulfate concentrations. High-resolution X-ray crystallographic structures of ortho-Cl and meta-thiazole-substituted benzene sulfonamide in complex with CA IV revealed the position of and interactions between the ligand and the protein. Sulfonamide inhibitor binding to CA IV is linked to several reactions-the deprotonation of the sulfonamide amino group, the protonation of CA-Zn(II)-bound hydroxide at the active site of CA IV, and the compensating reactions of the buffer. The dissection of binding-linked reactions yielded the intrinsic thermodynamic parameters, characterizing the interaction between CA IV and the sulfonamides in the binding-able protonation forms, including Gibbs energy, enthalpy, and entropy, that could be used for the characterization of binding to any CA in the process of drug design.

The first synthesis of 4-phenylbutenone derivative bromophenols including natural products and their inhibition profiles for carbonic anhydrase, acetylcholinesterase and butyrylcholinesterase enzymes

The first synthesis of (E)-4-(3-bromo-4,5-dihydroxyphenyl)but-3-en-2-one (1), (E)-4-(2-bromo-4,5-dihydroxyphenyl)but-3-en-2-one (2), and (E)-4-(2,3-dibromo-4,5-dihydroxyphenyl)but-3-en-2-one (3) was realized as natural bromophenols. Derivatives with mono OMe of 2 and 3 were obtained from the reactions of their derivatives with di OMe with AlCl₃. These novel 4-phenylbutenone derivatives were effective inhibitors of the cytosolic carbonic anhydrase I and II isoenzymes (hCA I and II), acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with K_i values in the range of 158.07-404.16pM for hCA I, 107.63-237.40pM for hCA II, 14.81-33.99pM for AChE and 5.64-19.30pM for BChE. The inhibitory effects of the synthesized novel 4-phenylbutenone derivatives were compared to acetazolamide as a clinical hCA I and II isoenzymes inhibitor and tacrine as a clinical AChE and BChE enzymes inhibitor.

Carbonic anhydrase inhibitory properties of some uracil derivatives

Inhibitors of carbonic anhydrase (CA) have been carried out in many therapeutic applications, especially antiglaucoma activity. In this study, we investigated some uracil derivatives (4–12) to inhibit human CA I (hCA I) and II (hCA II) isoenzymes. The K_I values of the compounds 4–12 are in the range of 0.085–428 µM for hCA I and of 0.1715–645 µM against hCA II, respectively. It is concluded from the kinetic investigations, all compounds used in the study act as competitive inhibitors with substrate, 4-NPA. Uracil derivatives are emerging agents for the inhibiton of carbonic anhydrase which could be used in biomedicine.

Synthesis and carbonic anhydrase inhibitory properties of novel chalcone substituted benzenesulfonamides

Carbonic anhydrases (CAs, EC 4.2.1.1) are crucial metalloenzymes involved in many bioprocesses, through catalysis of the reversible hydration/dehydration process of CO2/HCO3-. The inhibition of human CA isoforms I and II with a new series of sulfonamide derivatives incorporating substituted chalcone moieties were studied in this study. All these newly synthesized sulfonamides demonstrated important inhibitory profiles to these CA isoforms with KIs in the range of 9.88 to 55.43nM, making these compounds interesting leads, with potential applications in medicinal chemistry.

Gastroprotective activity of synthetic coumarins: Role of endogenous prostaglandins, nitric oxide, non-protein sulfhydryls and vanilloid receptors

Natural or synthetic coumarins showed gastroprotective and antiulcer activity in animal models. In this study, we have synthetized twenty coumarins using classic methods to evaluate their gastroprotective effects on the ethanol/HCl-induced gastric lesion model in mice at 20mg/kg. Among the coumarins synthetized, compounds 6 and 10 showed the greatest gastroprotective activity being as active as lansoprazole at 20mg/kg and reducing gastric lesions by 75 and 76%, respectively. Then, in a second experiment, compounds 6 and 10 were re-evaluated in order to understand the possible mode of gastroprotective activity. Regarding coumarin 6, the protective effect was reduced by pre-treatment of the mice with N-ethylmaleimide and l-NAME suggesting that sulfhydryl compounds and endogenous nitric oxide are involved in its gastroprotective activity. While for coumarin 10 the effect was reduced by pre-treatment with indomethacin suggesting that prostaglandins are positively involved in its gastroprotective activity.

Synthesis of 4-[2-(3,4-dimethoxybenzyl)cyclopentyl]-1,2-dimethoxybenzene Derivatives and Evaluations of Their Carbonic Anhydrase Isoenzymes Inhibitory Effects

Rearrangement of 1,6-bis(3,4-dimethoxyphenyl)hexane-1,6-dione (8) gave two isomeric products having cyclopentene moiety. Starting from the major product (3,4-dimethoxyphenyl)[2-(3,4-dimethoxyphenyl)cyclopent-1-en-1-yl]methanone (11), eight new compounds (16-23) were obtained by the reactions such as reduction (by catalytic hydrogenation and NaBH4 ), nitration, 1,4-addition, bromination, and esterification reactions. Carbonic anhydrases (CA, E.C.4.2.1.1) are ubiquitous metalloenzymes present in almost all living organism that catalyze a simple reaction, the conversion of carbon dioxide (CO2 ) and water (H2 O) to bicarbonate ion (HCO3 (-) ) and a proton (H(+) ). CA isoenzymes I and II (hCA I and II) inhibition effects of synthesized eleven new and four known compounds (8-13 and 15-23) were investigated. Inhibition studies of the hCA I and II with 4-[2-(3,4-dimethoxybenzyl)cyclopentyl]-1,2-dimethoxybenzene derivatives revealed that they possess effective inhibitory potency. Cytosolic hCA I and II isoenzymes were potently inhibited by new synthesized 4-[2-(3,4-dimethoxybenzyl)cyclopentyl]-1,2-dimethoxybenzene derivatives with Ki s in the range of 313.16-1537.00 nm against hCA I and in the range of 228.31-1927.31 nm against hCA II, respectively.

Kinetic and in silico studies of hydroxy-based inhibitors of carbonic anhydrase isoforms I and II

A series of hydroxy and phenolic compounds have been assayed for the inhibition of two physiologically relevant carbonic anhydrase (CA, EC 4.2.1.1) isozymes, the cytosolic human isozymes I and II. The investigated molecules showed inhibition constants in the range of 1.07-4003 and 0.09-31.5 μM at the hCA I and hCA II enzymes, respectively. In order to investigate the binding mechanisms of these inhibitors, in silico studies were also applied. Molecular docking scores of the studied compounds are compared using three different scoring algorithms, namely Glide/SP, Glide/XP and Glide/IFD. In addition, different ADME (absorption, distribution, metabolism and excretion) analysis was performed. All the examined compounds were found within the acceptable range of pharmacokinetic profiles.

Synthesis and biological evaluation of novel bromophenol derivatives as carbonic anhydrase inhibitors

Here, we provide an alternative synthesis of the natural bromophenol 3,4-dibromo-5-(2,3-dibromo-4,5-dihydroxybenzyl)-6-(ethoxymethyl)benzene-1,2-diol (3) and the first synthesis of (4,5-dihydroxy-2-methylphenyl)(3,4-dihydroxyphenyl)methanone (18) and its brominated derivatives 19-21. The compounds were characterized and tested against the two most studied members of the pH regulatory enzyme family, carbonic anhydrase (CA). The inhibitory potencies of the novel compounds and two natural bromophenols 2, 3 were analyzed at the human isoforms hCA I and hCA II as targets and the KI values were calculated. The KI values of the novel compounds were measured in the range of 13.7-32.7 mM for the hCA I isozyme and 0.65-1.26 mM for the hCA II isozyme. The structurally related compound 14 was also tested in order to understand the structure–activity relationship, and the clinically used sulfonamide acetazolamide (AZA)was tested for comparison reasons. All of the compounds exhibited competitive inhibition with 4-nitrophenylacetate as substrate. The compounds showed strong inhibitory activity against hCA I, being more effective as compared to the clinically used AZA (KI: 36.2 mM), but rather less activity against hCA II.

Synthesis and carbonic anhydrase inhibitory properties of novel bromophenols and their derivatives including natural products: vidalol B

A series of bisphenol, bromophenol, and methoxyphenol derivatives (2-24) including the natural bromophenols vidalol B, 3,4,6-tribromo-5-(2,5-dibromo-3,4-dihydroxybenzyl)benzene-1,2-diol (2) and 5,5'-methylenebis(3,4,6-tribromo-benzene-1,2-diol) (3) were prepared. In the current study, inhibition of four human carbonic anhydrase (hCA, EC 4.2.1.1) isozymes, I, II, IV, and VI, with these compounds 2-24 was investigated. The compounds 2-24 were found to be promising carbonic anhydrase inhibitors, some of which showed interesting inhibitory activities. Some of the compounds investigated here showed effective hCA inhibitory activity, and might be used as leads for generating novel carbonic anhydrase inhibitors which are valuable drug candidates for the treatment of glaucoma, epilepsy, gastric and duodenal ulcers, neurological disorders, and osteoporosis.