Sulfonamide inhibitors: a patent review 2013-present

Novel sulfonamides unveiled as potent anti-lung cancer agents via tumor pyruvate kinase M2 activation

This rational pursuit led to the identification of a novel sulfonamide derivative as a potent anti-lung cancer (LC) compound. Considering these results, we synthesized 38 novel sulfonamide derivatives with diverse skeletal structures. In vitro cytotoxicity assays revealed a potent and selective antiproliferative effect against A549 cells after evaluating a panel of cancer cell lines. Compound 9b has emerged as a potent activator of tumor pyruvate kinase M2 (PKM2), a protein known to play a critical role in LC. Apoptosis assays and cell cycle analysis demonstrated early apoptosis and G2 phase arrest. In silico studies demonstrated interactions between compound 9b and the activator binding site of PKM2. Surface plasmon resonance (SPR) experiments strongly indicated that 9b has a high affinity (K d of 1.378 nM) for PKM2. Furthermore, the increase in reactive oxygen species and decrease in lactate concentration suggested that compound 9b has significant anticancer effects. Notably, the increase in particle size following treatment with 9b suggested the tetramerization of PKM2. This work provides insights that might advance efforts to develop effective non-platinum anticancer agents.

Synthesis and examination of 1,2,4-triazine-sulfonamide hybrids as potential inhibitory drugs: Inhibition effects on AChE and GST enzymes in silico and in vitro conditions

The crucial functions of acetylcholinesterase (AChE) in neurotransmission and glutathione S-transferase (GST) in detoxification and cellular protection underscore their pivotal roles as key enzymes, essential for maintaining the integrity of neurological and cellular homeostasis. For this purpose, a series of 1,2,4-triazine-sulfonamide hybrids (3a-r) was successfully synthesized, and subsequently evaluated for their inhibitory effects on AChE and GST. The investigation was complemented by molecular docking studies and ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) predictions. The synthesized hybrids demonstrated significant promise in inhibiting both AChE and GST activities. Molecular docking analyses provided insights into the interactions between the compounds and the target enzymes, shedding light on potential binding modes and key amino acid residues involved. Furthermore, the study benefited from ADMET predictions, offering valuable information on the compounds' pharmacokinetic properties and potential toxicity. The promising results obtained from this comprehensive approach highlight the potential of these 1,2,4-triazine-sulfonamide hybrids as effective inhibitors of AChE and GST, paving the way for further development and optimization in the pursuit of novel therapeutic agents.

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

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

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

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

N,N-Diarylsulfonamide Reduces Proinflammatory Cytokine Interleukin-6 Levels in Cells through Nuclear Factor-κB Regulation

The arylsulfonamides were synthesized from aryl sulfonyl chloride and aromatic amines in dichloromethane in the presence of pyridine. The aryne chemistry was used to prepare diarylsulfonamide from arylsulfonamides and O-silylaryl triflate with CsF in acetonitrile at room temperature for 30 min. The synthesized compounds were evaluated for cytotoxicity followed by the cytokine/inflammatory marker's inhibition capability and its mechanism of action in RAW-264.7 cells. Elevated interleukin-6 (IL-6) levels have been reported in inflammatory conditions and inflammation-associated disorders. Hence, reducing the IL-6 levels in inflammatory conditions can serve as an attractive therapeutic target in dealing the inflammation. Among 42 compounds, seven compounds showed significant inhibition of IL-6 levels in lipopolysaccharide (LPS) challenged RAW-264.7 cells at 12.5 μM concentration. Further, investigation revealed that the IC50 value of these compounds for reducing IL-6 levels was found to be in the range of 2.6 to 9.7 μM. The promising compounds 5y (IC50 of 2.6 μM) and 5n (IC50 of 4.1 μM) along with other derivatives fulfil drug-likeness parameters laid down by Lipinski's rule of five. Further, RT-qPCR and Western-blot analysis revealed that treatment with 5n significantly reduced the expression of pro-inflammatory, inflammatory and macrophage marker's expression (IL-1β, CCL2, COX2 and CD68) compared to LPS control. The mechanistic evaluation showed that 5n exhibited anti-inflammatory properties by modulating the nuclear factor-κB (NF-κB) activation. The identified compound can be a promising candidate for further discovery efforts to generate a preclinical candidate effective in inflammation.

Stereoselective Synthesis of β, γ-Fused Bicyclic γ-Ureasultams via an Intramolecular Mannich and aza-Michael Addition Cascade

A novel approach has been developed for the synthesis of bicyclic β, γ-fused bicyclic γ-ureasultams containing two consecutive chiral centers through an intramolecular Mannich and aza-Michael addition cascade of alkenyl sulfamides. The straightforward practical procedure and readily available starting materials enable the synthesis of variously substituted ureasultams. In addition, bicyclic γ-ureasultams is a class of potential biotin analogues.

Acid-Catalyzed Oxy-aminomethylation of Styrenes

We report a strong Brønsted acid-catalyzed three-component oxy-aminomethylation of styrenes with sym-trioxane and sulfonamides or carbamates. This transformation provides a variety of 1,3-oxazinanes in moderate to good yields under mild reaction conditions. The obtained heterocycles can be readily transformed into the corresponding 1,3-amino alcohols, which are useful building blocks for the synthesis of pharmaceutically relevant molecules. Mechanistic studies suggest the intermediacy of an in situ formed 1,3,5-dioxazinane and a subsequent reaction with the olefin.

New palladium complexes with N-heterocyclic carbene and morpholine ligands: Synthesis, characterization, crystal structure, molecular docking, and biological activities

This work includes the synthesis of a new series of palladium-based complexes containing both morpholine and N-heterocyclic carbene (NHC) ligands. The new complexes were characterized using NMR (1 H and 13 C), FTIR spectroscopic, and elemental analysis techniques. The crystal structure of complex 1b was obtained by utilizing the single-crystal X-ray diffraction method. X-ray studies show that the coordination environment of palladium atom is completed by the carbene carbon atom of the NHC ligand, the nitrogen atom of the morpholine ring, and a pair of bromide ligand, resulting in the formation of slightly distorted square planar geometry. All complexes were determined for some metabolic enzyme activities. Results indicated that all the synthetic complexes exhibited powerful inhibitory actions against all aims as compared to the control molecules. Ki values of new morpholine-liganded complexes bearing 4-hydroxyphenylethyl group 1a-e for hCA I, hCA II, AChE, BChE, and α-glycosidase enzymes were obtained in the ranges 0.93-2.14, 1.01-2.03, 4.58-10.27, 7.02-13.75, and 73.86-102.65 µM, respectively. Designing of reported complexes is impacted by molecular docking study, and interaction with the current enzymes also proclaimed that compounds 1e (-12.25 kcal/mol for AChE and -11.63 kcal/mol for BChE), 1c (-10.77 kcal/mol and -9.26 kcal/mol for α-Gly and hCA II, respectively), and 1a (-8.31 kcal/mol for hCA I) are showing binding affinity and interaction from the synthesized five novel complexes.

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

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

Copper(II)-Mediated, Site-Selective C(sp2)-H Sulfonamidation of 1-Naphthylamines

An operationally simple and efficient protocol for copper(II)-mediated, picolinamido-directed C8-H sulfonamidation of 1-naphthylamine derivatives with various sulfonamides has been developed. Remarkably, this cross-dehydrogenative C-H/H-N coupling reaction exhibits a broad substrate scope with excellent functional group tolerance, is scalable, and enables an expeditious route to a library of unsymmetrical N-arylated sulfonamides in good to excellent yields with exclusive site selectivity.

Keto-bridged dual triazole-linked benzenesulfonamides as potent carbonic anhydrase and cathepsin B inhibitors

Background: Inhibition of human carbonic anhydrase (hCA) isoforms IX and XII with concurrent inhibition of cathepsin B is a promising approach for targeting cancers. Methods/results: 28 keto-bridged dual triazole-containing benzenesulfonamides were synthesized and tested, following the multitarget approach, for their efficacy as inhibitors of cathepsin B and hCA isoforms (I, II, IX, XII). The synthesized compounds showed excellent inhibition of CA isoforms (IX and XII) and cathepsin B. Compound 8i exhibited better and more selective inhibition of the cancer-associated isoform hCA IX as compared with acetazolamide (reference drug) and SLC-0111 (potent lead as carbonic anhydrase inhibitor). Molecular docking studies were also carried out. Conclusion: The present work gives important generalizations for the development of isoform-selective hCA inhibitors endowed with anti-cathepsin properties.

Synthesis and Computational Exploration of Morpholine Bearing Halogenated Sulfonamides as Potential Tyrosinase Inhibitors

In the presented work, a new series of three different 4-((3,5-dichloro-2-[(2/4-halobenzyl)oxy]phenyl)sulfonyl)morpholines was synthesized and the structure of these compounds were corroborated by 1 H-NMR & 13 C-NMR studies. The in vitro results established all the three compounds as potent tyrosinase inhibitors relative to the standard. The Kinetics mechanism plots established that compound 8 inhibited the enzyme non-competitively. The inhibition constants Ki calculated from Dixon plots for this compound was 0.0025 μM. Additionally, computational techniques were used to explore electronic structures of synthesized compounds. Fully optimized geometries were further docked with tyrosinase enzyme for inhibition studies. Reasonably good binding/interaction energies and intermolecular interactions were obtained. Finally, drug likeness was also predicted using the rule of five (RO5) and Chemical absorption, distribution, metabolism, excretion, and toxicity (ADMET) characteristics. It is anticipated that current experimental and computational investigations will evoke the scientific interest of the research community for the above-entitled compounds.

Halogen Bonding in Sulphonamide Co-Crystals: X···π Preferred over X···O/N?

Sulphonamides have been one of the major pharmaceutical compound classes since their introduction in the 1930s. Co-crystallisation of sulphonamides with halogen bonding (XB) might lead to a new class of pharmaceutical-relevant co-crystals. We present the synthesis and structural analysis of seven new co-crystals of simple sulphonamides N-methylbenzenesulphonamide (NMBSA), N-phenylmethanesulphonamide (NPMSA), and N-phenylbenzenesulphonamide (BSA), as well as of an anti-diabetic agent Chlorpropamide (CPA), with the model XB-donors 1,4-diiodotetrafluorobenzene (14DITFB), 1,4-dibromotetrafluorobenzene (14DBTFB), and 1,2-diiodotetrafluorobenzene (12DITFB). In the reported co-crystals, X···O/N bonds do not represent the most common intermolecular interaction. Against our rational design expectations and the results of our statistical CSD analysis, the normally less often present X···π interaction dominates the crystal packing. Furthermore, the general interaction pattern in model sulphonamides and the CPA multicomponent crystals differ, mainly due to strong hydrogen bonds blocking possible interaction sites.

Iridium-Catalyzed Direct Ortho-C-H Amidation of α-Ketoesters with Sulfonyl Azides Using a Transient Directing Group Strategy

Direct C-H amidation of α-ketoesters was accomplished using various organic azides as the amino source through the combination of transient directing group strategy and iridium catalysis. Excellent functional group tolerance and wide substrate scope were explored under simple and mild conditions. Importantly, it was found that the steric hindrance of the ester moiety played a pivotal role for the reaction efficacy. In addition, the reaction could be enlarged to gram scale, and several useful heterocycles were readily constructed via one-step late-stage derivatization.

New Ni(II) and Pd(II) complexes bearing derived sulfa drug ligands: synthesis, characterization, DFT calculations, and in silico and in vitro biological activity studies

In the present study, the synthesis of six new Ni(II) and Pd(II) complexes with three derived sulfamethoxazole drug ligands is reported. The coordination mode, geometry, and chemical formula of all the synthesized compounds have been determined by elemental analysis, mass spectrometry, emission atomic spectroscopy, conductivity measurements, magnetic susceptibility, FTIR, TGA, 1H-NMR, electronic absorption spectroscopy, SEM-EDX along with DFT calculations. The Schiff Base ligands were found to be bidentate and coordinated to the metal ions through sulfonamidic nitrogen and oxazolic nitrogen atoms leading to a square planar geometry for palladium (II) while a distorted octahedral geometry around Nickel (II) ion was suggested. Biological applications of the new complexes including in vitro antimicrobial, antioxidant and anticancer properties were investigated. The results showed that the new metal (II) compounds exhibit remarkable antibacterial inhibition activity against both Gram-positive and Gram-negative bacteria, in addition to noticeable DPPH free radical scavenging activity. The in vitro cytotoxicity assay of the complexes against cell lines of chronic myelogenous leukaemia (K562) showed promising potential for the application of the coordination compounds in antitumor therapy. Subsequently, to evaluate the pharmaceutical potential of the metal-containing compounds, pharmacokinetics and toxicity were studied by ADMET simulations while interactions between the complexes and bacterial proteins were evaluated by molecular docking.

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

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

Experimental and Computational Analysis of Newly Synthesized Benzotriazinone Sulfonamides as Alpha-Glucosidase Inhibitors

Diabetes mellitus is a chronic metabolic disorder in which the pancreas secretes insulin but the body cells do not recognize it. As a result, carbohydrate metabolism causes hyperglycemia, which may be fatal for various organs. This disease is increasing day by day and it is prevalent among people of all ages, including young adults and children. Acarbose and miglitol are famous alpha-glucosidase inhibitors but they complicate patients with the problems of flatulence, pain, bloating, diarrhea, and loss of appetite. To overcome these challenges, it is crucial to discover new anti-diabetic drugs with minimal side effects. For this purpose, benzotriazinone sulfonamides were synthesized and their structures were characterized by FT-IR, ¹H-NMR and ¹³C-NMR spectroscopy. In vitro alpha-glucosidase inhibition studies of all synthesized hybrids were conducted using the spectrophotometric method. The synthesized compounds revealed moderate-to-good inhibition activity; in particular, nitro derivatives 12e and 12f were found to be the most effective inhibitors against this enzyme, with IC₅₀ values of 32.37 ± 0.15 µM and 37.75 ± 0.11 µM. In silico studies, including molecular docking as well as DFT analysis, also strengthened the experimental findings. Both leading compounds 12e and 12f showed strong hydrogen bonding interactions within the enzyme cavity. DFT studies also reinforced the strong binding interactions of these derivatives with biological molecules due to their lowest chemical hardness values and lowest orbital energy gap values.

Crystallographic study, biological assessment and POM/Docking studies of pyrazoles-sulfonamide hybrids (PSH): Identification of a combined Antibacterial/Antiviral pharmacophore sites leading to in-silico screening the anti-Covid-19 activity

The discovery and development of new potent antimicrobial and antioxidant agents is an essential lever to protect living beings against pathogenic microorganisms and free radicals. In this regard, new functionalized pyrazoles have been synthesized using a simple and accessible approach. The synthesized aminobenzoylpyrazoles 3a-h and pyrazole-sulfonamides 4a-g were obtained in good yields and were evaluated in vitro for their antimicrobial and antioxidant activities. The structures of the synthesized compounds were determined using IR, NMR, and mass spectrometry. The structure of the compound 4b was further confirmed by single crystal X-ray diffraction. The results of the in vitro screening show that the synthesized pyrazoles 3 and 4 exhibit a promising antimicrobial and antioxidant activities. Among the tested compounds, pyrazoles 3a, 3f, 4e, 4f, and 4g have exhibited remarkable antimicrobial activity against some microorganisms. In addition, compounds 3a, 3c, 3e, 4a, 4d, 4f, and 4g have shown a significant antioxidant activity in comparison with the standard butylhydroxytoluene (BHT). Hence, compounds 3a, 4f, and 4g represent interesting dual acting antimicrobial and antioxidant agents. In fact, pyrazole derivatives bearing sulfonamide moiety (4a-g) have displayed an important antimicrobial activity compared to pyrazoles 3a-h, this finding could be attributed to the synergistic effect of the pyrazole and sulfonamide pharmacophores. Furthermore, Molecular docking results revealed a good interaction of the synthesized compounds with the target proteins and provided important information about their interaction modes with the target enzyme. The results of the POM bioinformatics investigations (Petra, Osiris, Molinspiration) show that the studied heterocycles present a very good non toxicity profile, an excellent bioavailability, and pharmacokinetics. Finally, an antiviral pharmacophore (O ^δ−, O ^δ−) was evaluated in the POM investigations and deserves all our attention to be tested against Covid-19 and its Omicron and Delta mutants.

Beta and Gamma Amino Acid-Substituted Benzenesulfonamides as Inhibitors of Human Carbonic Anhydrases

A series of novel benzenesulfonamide derivatives were synthesized bearing para-N β,γ-amino acid or para-N β-amino acid and thiazole moieties and their binding to the human carbonic anhydrase (CA) isozymes determined. These enzymes are involved in various illnesses, such as glaucoma, altitude sickness, epilepsy, obesity, and even cancer. There are numerous compounds that are inhibitors of CA and used as pharmaceuticals. However, most of them bind to most CA isozymes with little selectivity. The design of high affinity and selectivity towards one CA isozyme remains a significant challenge. The beta and gamma amino acid-substituted compound affinities were determined by the fluorescent thermal shift assay and isothermal titration calorimetry for all 12 catalytically active human carbonic anhydrase isozymes, showing the full affinity and selectivity profile. The structures of several compounds were determined by X-ray crystallography, and the binding mode in the active site of CA enzyme was shown.

Heteroaryl sulfonamide synthesis: scope and limitations

Heteroaryl sulfonamides are important structural motifs in the medicinal and agrochemical industries. However, their synthesis often relies on the use of heteroaryl sulfonyl chlorides, which are unstable and toxic reagents. Herein, we report a protocol that allows direct oxidative coupling of heteroaryl thiols and primary amines, readily available and inexpensive commodity chemicals. The transformation proceeds under mild reaction conditions and yields the desired N-alkylated sulfonamides in good yields. N-alkyl heteroaryl sulfonamides can be further transformed using a microwave-promoted Fukuyama-Mitsunobu reaction to N,N-dialkyl heteroaryl sulfonamides. The developed protocols thus enable the preparation of previously difficult to prepare sulfonamides (toxic reagents, harsh conditions, and low yields) under mild conditions.

Adsorption behavior and mechanism of sulfonamides on controllably synthesized covalent organic frameworks

In this work, four kinds of covalent organic framework (COF) materials (TpPa-1, TpBD, TpDT, and TFBBD) with different pore sizes or functional groups were synthesized by an ultrasonic method for the adsorption of five sulfonamides. Optimization experiments regarding the adsorption time, vortex speed, and pH were carried out to improve adsorption efficiency. In addition, kinetic and thermodynamic experiments were conducted to explore the adsorption mechanism of the sulfonamides on the different COFs. The adsorption processes of the five sulfonamides on the four COFs fit the pseudo-second-order kinetic model and Langmuir adsorption isotherm model. Additionally, pore filling, hydrogen bond interactions, and electrostatic attraction were found to be the main adsorption mechanisms.

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

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

Coumarins and Gastrointestinal Cancer: A New Therapeutic Option?

Cancers of the gastrointestinal (GI) tract are often life-threatening malignancies, which can be a severe burden to the health care system. Globally, the mortality rate from gastrointestinal tumors has been increasing due to the lack of adequate diagnostic, prognostic, and therapeutic measures to combat these tumors. Coumarin is a natural product with remarkable antitumor activity, and it is widely found in various natural plant sources. Researchers have explored coumarin and its related derivatives to investigate their antitumor activity, and the potential molecular mechanisms involved. These mechanisms include hormone antagonists, alkylating agents, inhibitors of angiogenesis, inhibitors of topoisomerase, inducers of apoptosis, agents with antimitotic activity, telomerase inhibitors, inhibitors of human carbonic anhydrase, as well as other potential mechanisms. Consequently, drug design and discovery scientists and medicinal chemists have collaborated to identify new coumarin-related agents in order to produce more effective antitumor drugs against GI cancers. Herein, we summarize the therapeutic effects of coumarin and its derivatives against GI cancer.

Unified Approach to Benzo[d]thiazol-2-yl-Sulfonamides

In this paper, we report a unified approach to N-substituted and N,N-disubstituted benzothiazole (BT) sulfonamides. Our approach to BT-sulfonamides starts from simple commercially available building blocks (benzo[d]thiazole-2-thiol and primary and secondary amines) that are connected via (a) a S oxidation/S-N coupling approach, (b) a S-N coupling/S-oxidation sequence, or via (c) a S-oxidation/S-F bond formation/SuFEx approach. The labile N-H bond in N-monoalkylated BT-sulfonamides (pK_a (BTSO₂N(H)Bn) = 3.34 ± 0.05) further allowed us to develop a simple weak base-promoted N-alkylation method and a stereoselective microwave-promoted Fukuyama-Mitsunobu reaction. N-Alkyl-N-aryl BT-sulfonamides were accessed with the help of the Chan-Lam coupling reaction. Developed methods were further used in stereo and chemoselective transformations of podophyllotoxin and several amino alcohols.

Insights on a new sulfonamide chalcone with potential antineoplastic application

Chalcones (E)-1,3-diphenyl-2-propene-1-ones, a class of biosynthetic precursor molecules of flavonoids, have a wide variety of biological applications. Besides the natural products, many synthetic derivatives and analogs became an object of continued interest in academia and industry. In this work, a synthesis and an extensive structural study were performed on a sulfonamide chalcone 1-Benzenesulfonyl-3-(4-bromobenzylidene)-2-(2-chlorophenyl)-2,3-dihydro-1H-quinolin-4-one with potential antineoplastic application. In addition, in silico experiments have shown that the sulfonamide chalcone fits well in the ligand-binding site of EGFR with seven μ-alkyl binding energy interactions on the ligand-binding site. Finally, the kinetic stability and the pharmacophoric analysis for EGFR indicated the necessary spatial characteristics for potential activity of sulfonamide chalcone as an antagonist.

Synthesis, biological activity and docking calculations of bis-naphthoquinone derivatives from Lawsone

Some metabolic enzyme inhibitors can be used as Multi-target-Directed-Ligands (MTDL) in Medicinal chemistry therefore, synthesis and determination of alternative inhibitors are essential. In this study, novel bis-napthoquinone derivatives (5a-o) were synthesized through a multi-component cascade reaction of two molecules of 2-hydroxy-1,4-naphthoquinone with an aromatic aldehyde in basic media using triethylamine as a catalyst. This novel heterocyclic derivatives (5a-o) are applied to inhibit the carbonic anhydrase (hCA I and hCA II) isoform in low levels of nano molecules with Ki values exist between 4.62 ± 1.01 to 70.45 ± 9.03 nM for hCA I and for hCA II which is physiologically dominant K_is values are in the range of 5.61 ± 1.04 to 73.26 ± 10.25 nM. Further these novel derivatives (5a-o) efficiently inhibit AChE with Ki values in the range of 0.13 ± 0.02 to 3.16 ± 0.56 nM. The compounds are also applied for BChE with Ki values varying between 0.50 ± 0.10 to 9.23 ± 1.15 nM. For α-glycosidase, the most efficient Ki values of 5e and 5f are 76.14 ± 9.60 and 95.27 ± 12.55 nM respectively. Finally, molecular docking calculations against enzymes (acetylcholinesterase, butyrylcholinesterase, and the human carbonic anhydrase I and II) are compared using biological activities of heterocyclic derivatives. After these calculations, an ADME/T analysis is performed to study the future medicinal use of heterocyclic derivatives from lawsone.

Fatty acid composition, enzyme inhibitory effect, antioxidant and anticancer activity of extract from Saponaria prostrata WILLD. subsp. anatolica HEDGE

This study attempts to evaluate the antioxidant, enzyme inhibitory, and anticancer properties as well as fatty acid compositions of endemic Saponaria prostrata WILLD. subsp. anatolica HEDGE. The gas chromatography-mass spectrometry (GC-MS) was used to determine the fatty acid content of methanol: dichloromethane extract from S. prostrata subsp. anatolica (SPA). Enzymatic activity was measured against acetylcholinesterase, butyrylcholinesterase and α-glucosidase. DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging activity and Ferric reducing antioxidant power assay (FRAP) were conducted to antioxidant properties. The anticancer effect of SPA on human MCF-7 breast cancer and human HCT116 colorectal cancer cell line was evaluated by WST-1 cell viability assay, colony formation assay and wound healing assay. In addition, human VEGF Elisa method was used to determine the anti-angiogenic effect, and the quantitative real-time PCR (qRT-PCR) method on p53, Bax and Bcl-2 mRNA levels were used to evaluate apoptosis. While high amounts of palmitic acid (40.8%), linoleic acid (17.75%) and α-linolenic acid (16.84%) were detected in the SPA, the total amount of unsaturated fatty acid (51.34%) was higher than the total amount of saturated fatty acid (48.66%). SPA displayed the most promising acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and α-glycosidase (AG) inhibitory activities (AChE: IC₅₀: 18.03 µg/mL, BuChE: IC₅₀: 44.24 µg/mL and AG: IC₅₀: 210.85 µg/mL). The half maximum inhibitory concentration (IC₅₀) of SPA in MCF-7 and HCT116 cells was determined as 259.79 µg/mL and 97.24 µg/mL, respectively. In addition, it was determined that SPA suppresses colony formation and wound closure, and suppresses angiogenesis as well as triggering apoptosis at a significant level. It is true that endemic S. prostrata subsp. anatolica is a potential source of functional food ingredients, but more analytical and in vivo experiments are needed to explore further secondary metabolite diversity and pharmacological properties.

Developments of small molecules as inhibitors for carbonic anhydrase isoforms

Carbonic anhydrases are ubiquitous, and their role in the hydration of carbon dioxide is essential for the survival of many tissues and organs. However, their association with many pathological diseases, especially in glaucoma, Alzheimer's, obesity, epilepsy, and tumorigenesis, has prompted the design and synthesis of novel carbonic anhydrase inhibitors (CAIs). Herein we describe (1) approaches used in the design of CAIs and (2) synthesis of small molecules as CAIs within the last five years. Despite the active research in this area, there are still more avenues to explore, especially selective inhibition of CA I, CA IX, and XII. These isoforms would continue to open up a diversity of carbonic anhydrase inhibitors containing 1,2,3-triazoles, imidazolone, pyrrolidone, thiadiazole, isatin, and glycoconjugates as part of their molecular frameworks.

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.

Synthesis and docking calculations of tetrafluoronaphthalene derivatives and their inhibition profiles against some metabolic enzymes

Syntheses of tetrahydroepoxy, O-allylic, O-prenylic, and O-propargylic tetrafluoronaphthalene derivatives, starting from 1-bromo-2,3,4,5,6-pentafluorobenzene, are reported here for the first time. The O-substituted tetrafluoronaphthalene derivatives were designed and also synthesized via a one-pot nucleophilic substitution reaction in excellent yields, whereas the tetrafluorotetrahydroepoxynaphthalene derivate was synthesized via a reduction reaction in excellent yield. The chemical structures of all the synthesized molecules were characterized by nuclear magnetic resonance, infrared spectroscopy, and high-resolution mass spectrometry techniques. In this study, a series of novel tetrafluoronaphthalene derivatives (2, 2a, 4-6) was tested toward several enzymes including α-glucosidase, acetylcholinesterase (AChE), and human carbonic anhydrase I and II (hCA I/II). The tetrafluoronaphthalene derivatives 2, 2a, and 4-6 showed IC₅₀ and K_i values in the range of 0.83-1.27 and 0.71-1.09 nM against hCA I, 1.26-1.85 and 1.45-5.31 nM against hCA II, 39.02-56.01 and 20.53-56.76 nM against AChE, and 15.27-34.12 and 22.58-30.45 nM against α-glucosidase, respectively. Molecular docking calculations were made to determine the biological activity values of the tetrafluoronaphthalene derivatives against the enzymes. After the calculations, ADME/T analysis was performed to examine the effects on human metabolism. Finally, these compounds had antidiabetic and anticholinesterase potentials.

Design, synthesis, molecular docking, and some metabolic enzyme inhibition properties of novel quinazolinone derivatives

3-Amino-2-ethylquinazolin-4(3H)-one (3) was synthesized in two steps from the reaction of amide (2), which was obtained from the treatment of methyl anthranilate (1) with propionyl chloride, with hydrazine. From the reaction of 3-amino-2-ethylquinazolin-4(3H)-one (3) with various aromatic aldehydes, novel benzylidenaminoquinazolin-4(3H)-one (3a-n) derivatives were synthesized. The structures of the novel molecules were characterized using infrared spectroscopy, nuclear magnetic resonance spectroscopy (¹ H-NMR and ¹³ C-NMR), and high-resolution mass spectroscopy. The novel compounds were tested against some metabolic enzymes, including α-glucosidase (α-Glu), acetylcholinesterase (AChE), and human carbonic anhydrases I and II (hCA I and II). The novel compounds showed K_i values in the range of 244-988 nM for hCA I, 194-900 nM for hCA II, 30-156 nM for AChE, and 215-625 nM for α-Glu. The binding affinities of the most active compounds were calculated as -7.636, -6.972, -10.080, and -8.486 kcal/mol for hCA I, hCA II, AChE, and α-Glu enzymes, respectively. The aromatic ring of the quinazoline moiety plays a critical role in the inhibition of the enzymes.

Discovery of secondary sulphonamides as IDO1 inhibitors with potent antitumour effects in vivo

Indoleamine 2,3-dioxygenase 1 (IDO1) as a key rate-limiting enzyme in the kynurenine pathway of tryptophan metabolism plays an important role in tumour immune escape. Herein, a variety of secondary sulphonamides were synthesised and evaluated in the HeLa cell-based IDO1/kynurenine assay, leading to the identification of new IDO1 inhibitors. Among them, compounds 5d, 5l and 8g exhibited the strongest inhibitory effect with significantly improved activity over the hit compound BS-1. The in vitro results showed that these compounds could restore the T cell proliferation and inhibit the differentiation of naïve CD4⁺ T cell into highly immunosuppressive FoxP3⁺ regulatory T (Treg) cell without affecting the viability of HeLa cells and the expression of IDO1 protein. Importantly, the pharmacodynamic assay showed that compound 5d possessed potent antitumour effect in both CT26 and B16F1 tumours bearing immunocompetent mice but not in immunodeficient mice. Functionally, subsequent experiments demonstrated that compound 5d could effectively inhibit tumour cell proliferation, induce apoptosis, up-regulate the expression of IFN-γ and granzyme B, and suppress FoxP3⁺ Treg cell differentiation, thereby activate the immune system. Thus, compound 5d could be a potential and efficacious agent for further evaluation.

Structure Activity Relationship of Key Heterocyclic Anti-Angiogenic Leads of Promising Potential in the Fight against Cancer

Pathological angiogenesis is a hallmark of cancer; accordingly, a number of anticancer FDA-approved drugs act by inhibiting angiogenesis via different mechanisms. However, the development process of the most potent anti-angiogenics has met various hurdles including redundancy, multiplicity, and development of compensatory mechanisms by which blood vessels are remodeled. Moreover, identification of broad-spectrum anti-angiogenesis targets is proved to be required to enhance the efficacy of the anti-angiogenesis drugs. In this perspective, a proper understanding of the structure activity relationship (SAR) of the recent anti-angiogenics is required. Various anti-angiogenic classes have been developed over the years; among them, the heterocyclic organic compounds come to the fore as the most promising, with several drugs approved by the FDA. In this review, we discuss the structure–activity relationship of some promising potent heterocyclic anti-angiogenic leads. For each lead, a molecular modelling was also carried out in order to correlate its SAR and specificity to the active site. Furthermore, an in silico pharmacokinetics study for some representative leads was presented. Summarizing, new insights for further improvement for each lead have been reviewed.

Design, synthesis, characterization, enzymatic inhibition evaluations, and docking study of novel quinazolinone derivatives

In this study, novel quinazolinone derivatives 7a-n were synthesized and evaluated against metabolic enzymes including α-glycosidase, acetylcholinesterase, butyrylcholinesterase, human carbonic anhydrase I, and II. These compounds exhibited high inhibitory activities in comparison to used standard inhibitors with K_i values in the range of 19.28-135.88 nM for α-glycosidase (K_i value for standard inhibitor = 187.71 nM), 0.68-23.01 nM for acetylcholinesterase (K_i value for standard inhibitor = 53.31 nM), 1.01-29.56 nM for butyrylcholinesterase (K_i value for standard inhibitor = 58.16 nM), 10.25-126.05 nM for human carbonic anhydrase I (K_i value for standard inhibitor = 248.18 nM), and 13.46-178.35 nM for human carbonic anhydrase II (K_i value for standard inhibitor = 323.72). Furthermore, the most potent compounds against each enzyme were selected in order to evaluate interaction modes of these compounds in the active site of the target enzyme. Cytotoxicity assay of the title compounds 7a-n against cancer cell lines MCF-7 and LNCaP demonstrated that these compounds do not show significant cytotoxic effects.

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.

Direct sulfonamidation of (hetero)aromatic C-H bonds with sulfonyl azides: a novel and efficient route to N-(hetero)aryl sulfonamides

N-Aryl sulfonamides belong to a highly important class of organosulfur compounds which are found in a number of FDA-approved drugs such as dofetilide, dronedarone, ibutilide, sotalol, sulfadiazine, sulfamethizole, vemurafenib, and many more. There is therefore continuing interest in the development of novel and convenient protocols for the preparation of these pharmaceutically important compounds. Recently, direct sulfonamidation of (hetero)aromatic C–H bonds with easily available sulfonyl azides has emerged as an attractive and powerful strategy to access N-(hetero)aryl sulfonamides where non-toxic nitrogen gas forms as the sole by-product. This review highlights recent advances and developments (2012–2020) in this fast growing research area with emphasis on the mechanistic features of the reactions.

N-Aryl sulfonamides belong to a highly important class of organosulfur compounds which are found in a number of FDA-approved drugs such as dofetilide, dronedarone, ibutilide, sotalol, sulfadiazine, sulfamethizole, vemurafenib, and many more.

Phytochemical conjugation as a potential semisynthetic approach toward reactive and reuse of obsolete sulfonamides against pathogenic bacteria

The emergence and reemergence of multidrug-resistant (MDR) bacteria and mycobacteria in community and hospital periphery have directly enhanced the hospitalization costs, morbidity and mortality, globally. The appearance of MDR pathogens, the currently used antibiotics, remains insufficient, and the development of potent antibacterial(s) is merely slow. Thus, the development of active antibacterials is the call of the day. The sulfonamides class of antibacterials was the most successful synthesized drug in the 19th century. Mechanically, sulfonamides were targeting bacterial folic acid biosynthesis and today, those are obsolete or clinically inactive. Nevertheless, the magic sulfonamide pharmacophore has been used continuously in several mainstream antibacterial, antidiabetic, antiviral drugs. Concomitantly, thousands of phytochemicals with antimicrobial potencies have been recorded and were commanded as alternate antibacterials toward control of MDR pathogens. However, none/very few isolated phytochemicals have gone up to the pure-drug stage due to the lack of the desired drug-likeness values and the required pharmacokinetic properties. Thus, chemical modification of parent drug remains as the versatile approach in antibacterial drug development. Improvement of clinically inactive sulfa drugs with suitable phytochemicals to develop active, low-toxic drug molecules followed by medicinal chemistry could be prudent. This review highlights such "sulfonamide-phytochemical" hybrid drug development research works for utilizing inactive sulfonamides and phytochemicals; the ingenious cost-effective and resource-saving hybrid drug concept could be a new trend in current antibacterial drug discovery to reactive the obsolete antibacterials.