New azafluorenones with cytotoxic and carbonic anhydrase inhibitory properties: 2-Aryl-4-(4-hydroxyphenyl)-5H-indeno[1,2-b]pyridin-5-ones

Domino reaction of bindone and 1,3-dipolarophiles for the synthesis of diverse spiro and fused indeno[1,2-a]fluorene-7,12-diones

The base promoted domino reaction of bindone ([1,2'-biindenylidene]-1',3,3'-trione) with common 1,3-dipolarophiles showed interesting molecular diversities, from which the unique spiro and fused indeno[1,2-a]fluorine derivatives were conveniently synthesized in satisfactory yields. In the presence of a base, bindone underwent formal [3 + 3] cycloaddition with satylidene malononitriles to give dispiro[indene-2,4'-fluorene-1',3''-indoline]. It also underwent formal [4 + 2] cycloaddition with 4-arylidene-pyrazol-3-ones to give diastereoisomeric spiro[indeno[1,2-a]fluorene-5,4'-pyrazole]. On the other hand, a triethylamine promoted reaction of three molecules of 1,3-indanediones and isatins in toluene afforded spiro[diindeno[2,1-b:2',1'-d]anthracene-11,3'-indoline] derivatives through the domino [4 + 2] cycloaddition and ring-expansion process.

Recent Strategies to Develop Innovative Photosensitizers for Enhanced Photodynamic Therapy

This review presents a robust strategy to design photosensitizers (PSs) for various species. Photodynamic therapy (PDT) is a photochemical-based treatment approach that involves the use of light combined with a light-activated chemical, referred to as a PS. Attractively, PDT is one of the alternatives to conventional cancer treatment due to its noninvasive nature, high cure rates, and low side effects. PSs play an important factor in photoinduced reactive oxygen species (ROS) generation. Although the concept of photosensitizer-based photodynamic therapy has been widely adopted for clinical trials and bioimaging, until now, to our surprise, there has been no relevant review article on rational designs of organic PSs for PDT. Furthermore, most of published review articles in PDT focused on nanomaterials and nanotechnology based on traditional PSs. Therefore, this review aimed at reporting recent strategies to develop innovative organic photosensitizers for enhanced photodynamic therapy, with each example described in detail instead of providing only a general overview, as is typically done in previous reviews of PDT, to provide intuitive, vivid, and specific insights to the readers.

Selective Synthesis of Diverse Spiro-oxindole-fluorene Derivatives via a DABCO-Promoted Annulation Reaction of Bindone and 3-Methyleneoxindoles

A DABCO-promoted annulation reaction of bindone ([1,2'-biindenylidene]-1',3,3'-trione) and 3-methyleneoxindoles showed very interesting molecular diversity under different reaction conditions. The base-promoted annulation reaction of bindone and 3-phenacylideneoxindoles in DCM at room temperature afforded spiro[indeno[1,2-a]fluorene-5,3'-indoline] derivatives in good yields and with high diastereoselectivity. However, the similar reaction of 2-(2-oxoindolin-3-ylidene) acetates resulted in Z/E-isomeric spiro[indeno[1,2-a]fluorene-5,3'-indolines] with diastereomeric ratios of 2:1 to 10:1. On the other hand, the DABCO-promoted annulation reaction of bindone and 3-methyleneoxindoles in acetonitrile at different temperatures selectively gave spiro[benzo[5,6]pentaleno[1,6a-b]naphthalene-7,3'-indoline] derivatives and complex dispiro[indoline-3,6'-[4b,6a]ethanoindeno[1,2-a]fluorene-14',3″-indolines] in satisfactory yields.

Selected Drug-Likeness Properties of 2-Arylidene-indan-1,3-dione Derivatives-Chemical Compounds with Potential Anti-Cancer Activity

2-Arylidene-indan-1,3-done derivatives have very different properties, thanks to which they find various applications in science, medicine, and industry. Selected derivatives show antiviral, antibacterial, and anti-inflammatory activity. This paper presents a procedure for the synthesis of a series of indan-1,3-dione derivatives that present antiproliferative activity. The aim of the work was to develop a method of simple synthesis and purification, evaluate the fulfillment of the Lipiński's and Veber's rule, and determine the potential scope of application of the obtained series of compounds. The structure of the synthesized compounds was confirmed, and their lipophilicity was determined using experimental and computational methods. Their antiproliferative activity against selected cell lines was tested in accordance with the MTT protocol; the ability to bind to albumin was tested, and the parameters related to the toxicity of substances in silico were determined. The selected compounds which showed antiproliferative activity were strongly bound to albumin and, in most cases, met the Lipiński's and Veber's rule. Thus, the obtained results suggest that 2-arylidene-indan-1,3-done derivatives appear to be good candidates for drugs with a potential leading structure for further development.

The Importance of Rhodanine Scaffold in Medicinal Chemistry: A Comprehensive Overview

After the clinical use of epalrestat that contains a rhodanine ring, in type II diabetes mellitus and diabetic complications, rhodanin-based compounds have become an important class of heterocyclic in the field of medicinal chemistry. Various modifications to the rhodanine ring have led to a broad spectrum of biological activity of these compounds. Synthesis of rhodanine derivatives, depended on advenced throughput scanning hits, frequently causes potent and selective modulators of targeted enzymes or receptors, which apply their pharmacological activities through different mechanisms of action. Rhodanine-based compounds will likely stay a privileged scaffold in drug discovery because of different probability of chemical modifications of the rhodanine ring. We have, therefore reviewed their biological activities and structure activity relationship.

Synthesis and biological evaluation of new pyrazolebenzene-sulphonamides as potential anticancer agents and hCA I and II inhibitors

Cancer is a disease characterized by the continuous growth of cells without adherence to the rules that healthy normal cells obey. Carbonic anhydrase I and II (CA I and CA II) inhibitors are used for the treatment of some diseases. The available drugs in the market have limitations or side effects, which bring about the need to develop new drug candidate compound(s) to overcome the problems at issue. In this study, new pyrazole-sulphonamide hybrid compounds 4-[5-(1,3-benzodioxol-5-yl)-3-aryl-4,5-dihydro-1 H -pyrazol-1-yl]benzenesulphonamides (4a - 4j) were designed to discover new drug candidate compounds. The compounds 4a - 4j were synthesized and their chemical structures were confirmed using spectral techniques. The hypothesis tested was whether an introduction of methoxy and polymethoxy group(s) lead to an increased potency selectivity expression (PSE) value of the compound, which reflects cytotoxicity and selectivity of the compounds. The cytotoxicity of the compounds towards tumor cell lines were in the range of 6.7 – 400 µM. The compounds 4i (PSE₂ = 461.5) and 4g (PSE₁ = 193.2) had the highest PSE values in cytotoxicity assays. Ki values of the compounds were in the range of 59.8 ± 3.0 - 12.7 ± 1.7 nM towards hCA I and in the range of 24.1 ± 7.1 - 6.9 ± 1.5 nM towards hCA II. While the compounds 4b, 4f, 4g, and 4i showed promising cytotoxic effects, the compounds 4c and 4g had the inhibitory potency towards hCA I and hCA II, respectively. These compounds can be considered as lead compounds for further research.

Synthesis and in vitro carbonic anhydrases and acetylcholinesterase inhibitory activities of novel imidazolinone-based benzenesulfonamides

New imidazolinone-based benzenesulfonamides 3a-e and 4a-e were synthesized in three steps and their chemical structures were confirmed by 1 H NMR (nuclear magnetic resonance), 13 C NMR, and high-resolution mass spectrometry. The benzenesulfonamides used were sulfacetamide (3a, 4a), sulfaguanidine (3b, 4b), sulfanilamide (3c, 4c), sulfadiazine (3d, 4d), sulfamerazine (3e), and sulfathiazole (4e). The compounds were evaluated against carbonic anhydrase (CA) and acetylcholinesterase (AChE) enzymes to obtain possible drug candidate/s. The lead compounds of the series were 3a and 4a against human CA (hCA) I, whereas 3d and 4a were leads against hCA II in terms of Ki values. Series 4 includes more effective CAs inhibitors than series 3 (except 3d). Series 4 compounds having a nitro group (except 4d) were 3.3-4.8 times more selective inhibitors than their corresponding analogues 3a-d in series 3, in which hydrogen was located in place of the nitro group, by considering Ki values against hCA II. Compounds 3c and 4c, where the sulfanilamide moiety is available, were the leads in terms of AChE inhibition with the lowest Ki values. The use of secondary sulfonamides was a more effective modification on CA inhibition, whereas the primary sulfonamide was the effective substitution in terms of AChE inhibitory potency.

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.

A straightforward, environmentally beneficial synthesis of spiro[diindeno[1,2-b:2',1'-e]pyridine-11,3'-indoline]-2',10,12-triones mediated by a nano-ordered reusable catalyst

A library of new spiro[diindeno[1,2-b:2',1'-e]pyridine-11,3'-indoline]-2',10,12-trione derivatives has been prepared in an efficient, one-pot pseudo four-component method mediated by a reusable heterogeneous nano-ordered mesoporous SO3H functionalized-silica (MCM-41-SO3H) catalyst. Excellent yields, short reaction times, as well as convenient non-chromatographic purification of the products and environmental benefits such as green and metal-free conditions constitute the main advantages of the developed synthetic methodology. The obtained fused indole-indenone dyes would be of interest to pharmaceutical and medicinal chemistry. Furthermore, due to their sensitivity to pH changes, they could be used as novel pH indicators.

In vitro anti-melanogenic effects of chimeric compounds, 2-(substituted benzylidene)-1,3-indanedione derivatives with a β-phenyl-α, β -unsaturated dicarbonyl scaffold

Tyrosinase is considered a key contributor to melanogenesis, and safe, potent tyrosinase inhibitors are needed for medical and cosmetic purposes to treat skin hyperpigmentation and prevent fruit and vegetable browning. According to our accumulated SAR data on tyrosinase inhibitors, the β-phenyl-α,β-unsaturated carbonyl scaffold in either E or Z configurations, can confer potent tyrosinase inhibitory activity. In this study, twelve indanedione derivatives were synthesized as chimeric compounds with a β-phenyl-α,β-unsaturated dicarbonyl scaffold. Two of these derivatives, that is, compounds 2 and 3 (85% and 96% inhibition, respectively), at 50 μM inhibited mushroom tyrosinase markedly more potently than kojic acid (49% inhibition). Docking studies predicted that compounds 2 and 3 both inhibited tyrosinase competitively, and these findings were supported by Lineweaver-Burk plots. In addition, both compounds inhibited tyrosinase activity and reduced melanin contents in B16F10 cells more than kojic acid without perceptible cytotoxicity. These results support the notion that chimeric compounds with the β-phenyl-α,β-unsaturated dicarbonyl scaffold represent promising starting points for the development of potent tyrosinase inhibitors.

Chromone–indanedione reactant: a bifunctional 3C synthon for diastereoselective construction of skeleton-diversified bispiro-[chromanocyclopentane-oxindole-indanedione]

A new type of bifunctional 3C synthon, a chromone–indanedione precursor, was employed for diastereoselective Michael/Michael cycloaddition with methyleneindolinones to generate a series of potentially bioactive bispiro-[chromanocyclopentane-oxindole-indanedione] frameworks with skeletal diversity in a single operation.

Synthesis and pharmacological effects of novel benzenesulfonamides carrying benzamide moiety as carbonic anhydrase and acetylcholinesterase inhibitors

N -(1-(4-Methoxyphenyl)-3-oxo-3-((4-( N -(substituted)sulfamoyl)phenyl)amino)prop-1-en-1-yl)benzamides 3a – g were designed since sulfonamide and benzamide pharmacophores draw great attention in novel drug design due to their wide range of bioactivities including acetylcholinesterase (AChE) and human carbonic anhydrase I and II (hCA I and hCA II) inhibitory potencies. Structure elucidation of the compounds was carried out by 1H NMR, 13C NMR, and HRMS spectra. In vitro enzyme assays showed that the compounds had significant inhibitory potential against hCA I, hCA II, and AChE enzymes at nanomolar levels. Ki values were in the range of 4.07 ± 0.38 – 29.70 ± 3.18 nM for hCA I and 10.68 ± 0.98 – 37.16 ± 7.55 nM for hCA II while Ki values for AChE were in the range of 8.91 ± 1.65 – 34.02 ± 5.90 nM. The most potent inhibitors 3g (Ki = 4.07 ± 0.38 nM, hCA I), 3c (Ki = 10.68 ± 0.98 nM, hCA II ) , and 3f (Ki = 8.91 ± 1.65 nM, AChE) can be considered as lead compounds of this study with their promising bioactivity results. Secondary sulfonamides showed promising enzyme inhibitory effects on AChE while primary sulfonamide derivative was generally effective on hCA I and hCA II isoenzymes.

Design, synthesis and biological evaluation of novel pyxinol derivatives with anti-heart failure activity

Heart failure (HF) is an important and leading cause of substantial morbidity and mortality globally. The angiotensin-converting enzymatic (ACE) is the causative source for congestive heart failure. Natural products and its derivatives play a vital role in drug discovery and development owing to their efficacy and low toxicity. Pyxinol is a potent natural agent for cardiovascular disease. Thus we investigated the effect on ACE and HF of pyxinol derivatives. We designed and synthesized 32 novel fatty acid ester derivatives of pyxinol via esterification. Among them, compounds 2e (IC₅₀=105 nM) and 3b (IC₅₀=114 nM) displayed excellent ACE inhibitory activity in vitro, and exhibited non-toxic to H9c2 cells. The interactions between ACE and compounds were predicted by molecular docking respectively. In verapamil-induced zebrafish HF model, the activity assay showed that these two derivatives could improve cardiovascular physiological indexes including heart beats, venous congestion, heart dilation, cardiac output, ejection fraction and fractional shortening in a dose-dependent manner. A UPLC-QTOF-MS-based serum metabolomics approach was applied to explore the latent mechanism. A total of 25 differentiated metabolites and 8 perturbed metabolic pathways were identified. These results indicated that pyxinol fatty acid ester derivatives 2e and 3b might be considered as potent drug candidates against heart failure and deserved further research and development.

Novel quinazolin-sulfonamid derivatives: synthesis, characterization, biological evaluation, and molecular docking studies

In the design of novel drugs, the formation of hybrid molecules via the combination of several pharmacophores can give rise to compounds with interesting biochemical profiles. A series of novel quinazolin-sulfonamid derivatives (9a-m) were synthesized, characterized and evaluated for their in vitro antidiabetic, anticholinergics, and antiepileptic activity. These synthesized novel quinazolin-sulfonamid derivatives (9a-m) were found to be effective inhibitor molecules for the α-glycosidase, human carbonic anhydrase I and II (hCA I and hCA II), butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) enzyme, with Ki values in the range of 100.62 ± 13.68-327.94 ± 58.21 nM for α-glycosidase, 1.03 ± 0.11-14.87 ± 2.63 nM for hCA I, 1.83 ± 0.24-15.86 ± 2.57 nM for hCA II, 30.12 ± 3.81-102.16 ± 13.87 nM for BChE, and 26.16 ± 3.63-88.52 ± 20.11 nM for AChE, respectively. In the last step, molecular docking calculations were made to compare biological activities of molecules against enzymes which are achethylcholinesterase, butyrylcholinesterase and α-glycosidase.Communicated by Ramaswamy H. Sarma.

Green and Fast Synthesis of 2-Arylidene-indan-1,3-diones Using a Task-Specific Ionic Liquid

A novel method for condensation reaction of indan-1,3-dione with various aldehydes which are efficiently catalyzed by a task-specific ionic liquid, 2-hydroxyethylammonium formate, to provide the corresponding 2-arylidenindane-1,3-diones has been developed. This green, low-cost, high-yield, and fast reaction takes place at room temperature without the use of any solvent and catalyst. A plausible reaction mechanism that involves ionic liquid-assisted activation is also discussed. This work is the first report of ionic liquids as a reaction medium and catalyst for the synthesis of 2-arylidenindane-1,3-diones.

Synthesis of benzamide derivatives with thiourea-substituted benzenesulfonamides as carbonic anhydrase inhibitors

The novel compounds with the chemical structure of N-({4-[N'-(substituted)sulfamoyl]phenyl}carbamothioyl)benzamide (1a-g) and 4-fluoro-N-({4-[N'-(substituted)sulfamoyl]phenyl}carbamothioyl)benzamide (2a-g) were synthesized as potent and selective human carbonic anhydrase (hCA) I and hCA II candidate inhibitors. The aryl part was changed to sulfacetamide, sulfaguanidine, sulfanilamide, sulfathiazole, sulfadiazine, sulfamerazine, and sulfametazine. The K_i values of compounds 1a-g were in the range of 20.73 ± 4.32 to 59.55 ± 13.07 nM (hCA I) and 5.69 ± 0.43 to 44.81 ± 1.08 nM (hCA II), whereas the K_i values of compounds 2a-g were in the range of 13.98 ± 2.57 to 75.74 ± 13.51 nM (hCA I) and 8.15 ± 1.5 to 49.86 ± 6.18 nM (hCA II). Comparing the K_i values of the final compounds and acetazolamide, compound 1c with the sulfanilamide moiety (K_i  = 5.69 ± 0.43 nM, 8.8 times) and 2f with the sulfamerazine moiety (K_i  = 8.15 ± 1.5 nM, 6.2 times) demonstrated promising and selective inhibitory effects against the hCA II isoenzyme, the main target protein in glaucoma. Furthermore, compounds 1d (K_i  = 20.73 ± 4.32, 4 times) and 2d (K_i  = 13.98 ± 2.57, 5.9 times), which have the sulfathiazole moiety, were found as potent hCA I inhibitors. Compounds 1c and 2f can be considered as the lead compounds determined in the present study, which can be investigated further to alleviate glaucoma symptoms.

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.

A Review on Onychine and its Analogs: Synthesis and Biological Activity

BACKGROUND

Onychine is a 4-azafluorenone alkaloid isolated from the Annonaceae family, in low concentrations. Onychine and its analogs exhibit a wide range of pharmacological activities such as antifungal, antibacterial, anticancer, and antimalarial. Because of the high bioactivity of some 4-azafluorenone derivatives, several synthetic methods have been developed for their procurement.

OBJECTIVE

Considering the importance of these alkaloids, we aim to present the main synthetic approaches to onychines and its derivatives and the biological activity of some 4-azafluorenones.

METHODS

The most prominent methodologies for the synthesis of onychines were reviewed.

RESULTS

In this work, we cover many synthetic approaches for the synthesis of onychine and 4-azafluorenone derivatives including intramolecular cyclizations, multicomponent reactions, microwave-assisted multicomponent reactions, Diels-alder reactions, among others. Moreover, we also review the biological activity of 4-azafluorenones.

CONCLUSION

4-azafluorenones have risen as prominent structures in medicinal chemistry; however, most of the time, access to new derivatives involves toxic catalysts, harsh reaction conditions, and long-step procedures. Therefore, the development of new synthetic routes with more operational simplicity, simple purification procedure, good yields, and low environmental impact, is desirable.

Domino Reaction of Aromatic Aldehydes and 1,3-Indanediones for Construction of Bicyclo[2.2.2]octanes and Dibenzo[b,g]indeno[1',2':3,4]fluoreno[1,2-d]oxonines

Triethylamine promoted the pseudo-five-component reaction of aromatic aldehyde with four molecules of 1,3-indanediones in refluxing ethanol to give unique polycyclic bicyclo[2.2.2]octane derivatives containing bridged- and spiro-indanone scaffolds in good yields. The mechanistic studies supported that the reaction included base-catalyzed cyclotrimerization of 1,3-indanedione to give an active cyclic diene and the sequential Diels-Alder reaction with in situ generated 2-arylidene-1,3-indanediones as electron-deficient dienophiles. On the other hand, the pseudo-four-component reaction of salicylaldehyde with 1,3-indanedione afforded the dibenzo[b,g]indeno[1',2':3,4]fluoreno[1,2-d]oxonines in high yields. This reaction clearly demonstrated the high efficiency, molecular convergence, atom-economy, and impressive selectivity of multicomponent reactions.

Tuning Organelle Specificity and Photodynamic Therapy Efficiency by Molecular Function Design

Efficient organic photosensitizers (PSs) have attracted much attention because of their promising applications in photodynamic therapy (PDT). However, guidelines on their molecular design are rarely reported. In this work, a series of PSs are designed and synthesized based on a triphenylamine-azafluorenone core. Their structure-property-application relationships are systematically studied. Cationization is an effective strategy to enhance the PDT efficiency of PSs by targeting mitochondria. From the molecularly dispersed state to the aggregate state, the fluorescence and the reactive oxygen species generation efficiency of PSs with aggregation-induced emission (AIE) increase due to the restriction of the intramolecular motions and enhancement of intersystem crossing. Cationized mitochondrion-targeting PSs show higher PDT efficiency than that of nonionized ones targeting lipid droplets. The ability of AIE PSs to kill cancer cells can be further enhanced by combination of PDT with radiotherapy. Such results should trigger research enthusiasm for designing and synthesizing AIE PSs with better PDT efficiency and properties.

Inhibition profiles of Voriconazole against acetylcholinesterase, α-glycosidase, and human carbonic anhydrase I and II isoenzymes

In this work, the inhibitory activity of Voriconazole was measured against some metabolic enzymes, including human carbonic anhydrase (hCA) I and II isoenzymes, acetylcholinesterase (AChE), and α-glycosidase; the results were compared with standard compounds including acetazolamide, tacrine, and acarbose. Half maximal inhibition concentration (IC₅₀ ) values were obtained from the enzyme activity (%)-[Voriconazole] graphs, whereas K_i values were calculated from the Lineweaver-Burk graphs. According to the results, the IC₅₀ value of Voriconazole was 40.77 nM for α-glycosidase, while the mean inhibition constant (K_i ) value was 17.47 ± 1.51 nM for α-glycosidase. The results make an important contribution to drug design and have pharmacological applications. In addition, the Voriconazole compound demonstrated excellent inhibitory effects against AChE and hCA isoforms I and II. Voriconazole had K_i values of 29.13 ± 3.57 nM against hCA I, 15.92 ± 1.90 nM against hCA II, and 10.50 ± 2.46 nM against AChE.

Construction of Dispiro-Indenone Scaffolds via Domino Cycloaddition Reactions of α,β-Unsaturated Aldimines with 2-Arylidene-1,3-indenediones and 2,2'-(Arylmethylene)bis(1,3-indenediones)

The catalyst-free domino reaction of α,β-unsaturated N-alkyl or N-arylaldimines with two molecules of 2-arylidene-1,3-indanediones in dry acetonitrile resulted in polysubstituted spiro[indene-2,3'-indeno[2',1':5,6]pyrano[2,3-b]pyridines] in moderate to good yields and with high diastereoselectivity. The reaction mechanism included sequential aza/oxa-Diels-Alder reactions via both endo-transition states. On the other hand, the catalyst-free domino reaction of α,β-unsaturated N-arylaldimines with 2,2'-(arylmethylene)bis(1,3-indenediones) afforded the mixed diastereoisomeric dispiro[indene-2,1'-cyclohexane-3',2″-indene] derivatives in satisfactory yields. The reaction mechanism of this formal [3 + 3] cycloaddition was believed to proceed with sequential nucleophilic 1,4-/1,2-additions.

The green synthesis and molecular docking of novel N-substituted rhodanines as effective inhibitors for carbonic anhydrase and acetylcholinesterase enzymes

Recently, inhibition effects of enzymes such as acetylcholinesterase (AChE) and carbonic anhydrase (CA) has appeared as a promising approach for pharmacological intervention in a variety of disorders such as epilepsy, Alzheimer's disease and obesity. For this purpose, novel N-substituted rhodanine derivatives (RhAs) were synthesized by a green synthetic approach over one-pot reaction. Following synthesis the novel compounds, RhAs derivatives were tested against AChE and cytosolic carbonic anhydrase I, and II (hCAs I, and II) isoforms. As a result of this study, inhibition constant (Ki) were found in the range of 66.35 ± 8.35 to 141.92 ± 12.63 nM for AChE, 43.55 ± 14.20 to 89.44 ± 24.77 nM for hCA I, and 16.97 ± 1.42 to 64.57 ± 13.27 nM for hCA II, respectively. Binding energies were calculated with docking studies as -5.969, -5.981, and -9.121 kcal/mol for hCA I, hCA II, and AChE, respectively.

Synthesis and biological evaluation of some new mono Mannich bases with piperazines as possible anticancer agents and carbonic anhydrase inhibitors

New mono Mannich bases, (2-(4-hydroxy-3-((4-substituephenylpiperazin-1-yl)methyl)benzylidene)-2,3-dihydro-1H-inden-1-one), were prepared to evaluate their cytotoxic/anticancer properties and also their inhibitory effects on human carbonic anhydrase I and II isoenzymes (hCA I and II). Amine part was changed as [N-phenylpiperazine (1), N-benzylpiperazine (2), 1-(2-fluorophenyl)piperazine (3), 1-(4-fluorophenyl)piperazine (4), 1-(2-methoxyphenyl)piperazine (5)]. The structure of the synthesized compounds was characterized by ¹H NMR, ¹³C NMR and HRMS spectra. Cytotoxicity results of the series pointed out that the compound 4 had the highest tumor selectivity value (TS: 59.4) possibly by inducing necrotic cell death in series. Additionally, all compounds synthesized showed a good inhibition profile towards hCA I and II isoenzymes with the Ki values between 29.6 and 58.4 nM and 38.1-69.7 nM, respectively. These values were lower than the reference compound AZA. However, it seems that the compounds 4 and 2 can be considered as lead compounds of CA studies with the lowest Ki values in series for further designs.

Design, synthesis, and carbonic anhydrase inhibition activity of benzenesulfonamide-linked novel pyrazoline derivatives

Carbonic anhydrases (CA, EC 4.2.1.1) are Zinc metalloenzymes and are present throughout most living organisms. Among the catalytically active isoforms are the cytosolic CA I and II, and tumor-associated CA IX and CA XII. The carbonic anhydrase (CA) inhibitory activities of newly synthesized pyrazoline-linked benzenesulfonamides 18-33 against human CA (hCA) isoforms I, II, IX, and XII were measured and compared with that of acetazolamide (AAZ), a standard inhibitor. Potent inhibitory activity against hCA I was exerted by compounds 18-25, with inhibition constant (KI) values of 87.8-244.1 nM, which were greater than that of AAZ (KI, 250.0 nM). Compounds 19, 21, 22, 29, 30, and 32 were proven to have inhibitory activities against hCA IX with KI values (5.5-37.0 nM) that were more effective than or nearly equal to that of AAZ (KI, 25.0 nM). Compounds 20-22, and 30 exerted potent inhibitory activities (KIs, 7.1-10.1 nM) against hCA XII, in comparison with AAZ (KI, 5.7 nM).

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.