Coumarin Ring Research Articles

Chemical library design, QSAR modeling and molecular dynamics simulations of naturally occurring coumarins as dual inhibitors of MAO-B and AChE

Coumarins are a highly privileged scaffold in medicinal chemistry. It is present in many natural products and is reported to display various pharmacological properties. A large plethora of compounds based on the coumarin ring system have been synthesized and were found to possess biological activities such as anticonvulsant, antiviral, anti-inflammatory, antibacterial, antioxidant as well as neuroprotective properties. Despite the wide activity spectrum of coumarins, its naturally occurring derivatives are yet to be investigated in detail. In the current study, a chemical library was created to assemble all chemical information related to naturally occurring coumarins from the literature. Additionally, a multi-stage virtual screening combining QSAR modeling, molecular docking, and ADMET prediction was conducted against monoamine oxidase B and acetylcholinesterase, two relevant targets known for their neuroprotective properties and ‘disease-modifying’ potential in Parkinson’s and Alzheimer’s disease. Our findings revealed ten coumarin derivatives that may act as dual-target drugs against MAO-B and AChE. Two coumarin candidates were selected from the molecular docking study: CDB0738 and CDB0046 displayed favorable interactions for both proteins as well as suitable ADMET profiles. The stability of the selected coumarins was assessed through 100 ns molecular dynamics simulations which revealed promising stability through key molecular interactions for CDB0738 to act as dual inhibitor of MAO-B and AChE. However, experimental studies are necessary to evaluate the bioactivity of the proposed candidate. The current results may generate an increasing interest in bioprospecting naturally occurring coumarins as potential candidates against relevant macromolecular targets by encouraging virtual screening studies against our chemical library. Communicated by Ramaswamy H. Sarma

A Combined in Silico and Structural Study Opens New Perspectives on Aliphatic Sulfonamides, a Still Poorly Investigated Class of CA Inhibitors

Aliphatic sulfonamides are an interesting class of carbonic anhydrase inhibitors (CAIs) proven to be effective for several carbonic anhydrase (CA) isoforms involved in pathologic states. Here we report the crystallographic structures of hCA II in complex with two aliphatic sulfonamides incorporating coumarin rings, which showed a good inhibition and selectivity for this isoform. Although these two molecules have a very similar chemical structure, differing only in the substitution of the two aliphatic hydrogen atoms with two fluorine atoms, they adopt a significantly different binding mode within the enzyme active site. Theoretical binding free energy calculations, performed to rationalize these data, showed that a delicate balance of electrostatic and steric effects modulate the protein-ligand interactions. Data presented here can be fruitfully used for the rational design of novel and effective isozyme-specific inhibitor molecules.

Vibrationally resolved two-photon electronic spectra including vibrational pre-excitation: Theory and application to VIPER spectroscopy with two-photon excitation.

Following up on our previous work on vibrationally resolved electronic absorption spectra including the effect of vibrational pre-excitation [von Cosel et al., J. Chem. Phys. 147, 164116 (2017)], we present a combined theoretical and experimental study of two-photon-induced vibronic transitions in polyatomic molecules that are probed in the VIbrationally Promoted Electronic Resonance experiment using two-photon excitation (2P-VIPER). In order to compute vibronic spectra, we employ time-independent and time-dependent methods based on the evaluation of Franck-Condon overlap integrals and Fourier transformations of time-domain correlation functions, respectively. The time-independent approach uses a generalized version of the FCclasses method, while the time-dependent approach relies on the analytical evaluation of Gaussian moments within the harmonic approximation, including Duschinsky rotation effects. For the Coumarin 6 dye, two-dimensional 2P-VIPER experiments involving excitation to the lowest-lying singlet excited state (S1) are presented and compared with corresponding one-photon VIPER spectra. In both cases, coumarin ring modes and a CO stretch mode show VIPER activity, albeit with different relative intensities. Selective pre-excitation of these modes leads to a pronounced redshift of the low-frequency edge of the electronic absorption spectrum, which is a prerequisite for the VIPER experiment. Theoretical analysis underscores the role of interference between Franck-Condon and Herzberg-Teller effects in the two-photon experiment, which is at the root of the observed intensity distribution.

Oxidative Coupling of 4‐Hydroxycoumarins with Quinoxalin‐2(1H)‐ones Induced by Visible Light under Aerobic Conditions

AbstractDirect and selective C(sp2)−H/C(sp2)−H cross‐dehydrogenative coupling has become a promising strategy to increase molecular complexity with a high atom economy. This study describes an efficient and straightforward protocol for the regioselective C3‐H/C3‐H cross‐coupling of 4‐hydroxycoumarin derivatives with quinoxalin‐2(1H)‐ones, including late‐stage modification of natural drugs, promoted by visible light under aerobic conditions at room temperature. With this approach, a wide range of hybrid drug‐like molecules were prepared, using air as the terminal oxidant. Remarkably, the C4‐OH group at the coumarin ring is essential for the reaction and has been used as a handle for diverse functionalizations of the final products. Moreover, sunlight can promote the reaction under very mild and sustainable conditions, even on a gram scale. Qualitative and semi‐quantitative tools were used to demonstrate the greenness advance of this methodology over previously reported ones. Several experiments were conducted to propose a plausible mechanism for this transformation.

Biological evaluation of novel amidino substituted coumarin-benzazole hybrids as promising therapeutic agents.

Herein we present the design and the synthesis of novel substituted coumarin-benzimidazole/benzothiazole hybrids bearing a cyclic amidino group on the benzazole core as biologically active agents. All prepared compounds were evaluated for their in vitro antiviral and antioxidative activity as well as for their in vitro antiproliferative activity against a panel of several human cancer cell lines. Coumarin-benzimidazole hybrid 10 (EC50 9.0-43.8 μM) displayed the most promising broad spectrum antiviral activity, while two other coumarin-benzimidazole hybrids 13 and 14 showed the highest antioxidative capacity in the ABTS assay, superior to the reference standard BHT (IC50 0.17 and 0.11 mM, respectively). Computational analysis supported these results and demonstrated that these hybrids benefit from the high C-H hydrogen atom releasing tendency of the cationic amidine unit, and the pronounced ease with which they can liberate an electron, promoted by the electron-donating diethylamine group on the coumarin core. The coumarin ring substitution at position 7 with a N,N-diethylamino group also caused a significant enhancement of the antiproliferative activity, with the most active compounds being derivatives with a 2-imidazolinyl amidine group 13 (IC50 0.3-1.9 μM) and benzothiazole derivative with a hexacyclic amidine group 18 (IC50 1.3-2.0 μM).

Coumarin‐Based Reversible Fluorescent Chemosensors for the Sequential Detection of Copper and Citrate Ions

AbstractTwo novel coumarin‐based Schiff‐base chemosensors are presented. Courtesy to an extended conjugation between the coumarin ring and the attached π‐containing groups, both chemosensors display noteworthy photo‐physical properties including emission maxima at >550 nm. Both chemosensors function as the selective sensors for the ‘turn‐off’ detection of copper ion with the significant nanomolar detection limits. The sensing event was investigated through proton NMR and mass spectroscopy; pH studies; life‐time and quantum yield measurements and DFT studies. The solution‐generated [chemosensor‐Cu] species illustrated remarkably selective secondary ‘turn‐on’ detection of the citrate ion. The sequential detection of the copper and citrate ions have been utilized for the construction of logic gates as well as several low‐cost detection methods.

GLP-1 Targeted Novel 3-phenyl-7-hydroxy Substituted Coumarins Mitigate STZ-induced Pancreatic Damage and Improve Glucose Homeostasis in OGTT Method.

Worldwide, type 2 diabetes mellitus accounts for a considerable burden of disease, with an estimated global cost of >800 billion USD annually. For this reason, the search for more effective and efficient therapeutic anti-diabetic agents is continuing. Recent studies support the search for coumarins or related compounds with potential blood glucose-lowering properties. The study aims to design, synthesize and evaluate the hypoglycemic activity of a new class of 7-hydroxy coumarin derivatives. To explore and establish the in-silico-driven pharmacological role of a new class of 7- hydroxy coumarin derivatives as the therapeutic strategies against type 2 diabetes mellitus. A new class of 7-hydroxy coumarin derivatives was designed by assessment of their physicochemical properties and molecular docking against the Glucagon-like peptide-1 (GLP-1) receptor. Two novel series of 30 compounds were synthesized. The chemical structures of all the synthesized analogues have been elucidated by spectral studies of IR, 1H-NMR, and mass spectroscopy. After considering the molecular docking score and their physicochemical properties, the compounds were screened out for the evaluation of their hypoglycemic potential. The compounds were investigated for their hypoglycemic activity using a streptozotocin (STZ) induced diabetic model and an oral glucose tolerance test (OGTT) method at different dose levels. The molecular docking studies of synthesized derivatives reveal significant molecular interaction with the various amino acid residues of the GLP-1 receptor. IR spectral analysis revealed a strong band of -NH stretching in the range of 3406.7-3201.61 cm-1 and one strong band for the lactone carbonyl group of the coumarin ring in the range of 1722.0-1703.5 cm-1, confirming the chemical structure of all produced compounds. The synthesized coumarin analogues with the best docking score exhibited remarkable hypoglycemic potential as assessed by the STZ model and the OGTT method. Coumarin derivatives explored a good structure-activity relationship (SAR) and produced significant hypoglycemic potential.

Substitution position effects of an electron-withdrawing group on the tautomer fluorescence of Coumarin–urea derivatives with an acetate anion

To improve the fluorescence properties of coumarin–urea derivatives having a phenyl urea group bound at the 7-position of the coumarin ring (7CU derivatives), the substitution position effects of the electron-withdrawing group, CF3, on the photochemical behaviors of 7CU derivatives were investigated in the absence and presence of an acetate anion (AcO−). Both o- and m-CF3-7CU were prepared besides p-CF3-7CU, all of which bear a CF3 group at different positions on a phenyl ring opposite to the coumarin ring (o-, m-, and p-isomers, respectively). These three CF3–7CU derivatives underwent excited-state intermolecular proton transfer (ESPT) in the presence of AcO− followed by emissive tautomer formation, resulting in dual fluorescence. To elucidate the fluorescence state of tautomer, we compared the spectroscopic results of CF3–7CU derivatives including the rate constants for ESPT with regard to the inductive and resonance effects. The results revealed that the emission yield of tautomer of o-CF3-7CU was an order of magnitude larger than those of both m- and p-CF3-7CU due to the effective inductive effect of a CF3 group; this observation indicates that o-CF3-7CU is a suitable anion sensor. Our findings will contribute to the development of new molecular designs for fluorescent probes with excellent visibility.

Design, synthesis and biological evaluation of coumarin derivatives as potential BRD4 inhibitors

The bromodomain and extra-terminal (BET) bromodomains, particularly BRD4, have been identified as promising therapeutic targets in the treatment of many human disorders such as cancer. Coumarin is a highly privileged moiety for the development of novel anticancer drugs which has been identified in clinical trials for the treatment of various cancers. Herein, we modified BRD4i ABBV-075 with a coumarin ring and synthesized a novel series of coumarin derivatives as BRD4 inhibitors. Among them, the representative compound 27d showed excellent BRD4 inhibitory activities with an IC50 value of 99 nM in the TR-FRET assay. Compared with ABBV-075, compound 27d displayed a favorable cell proliferation inhibitory activity in solid tumors, such as MCF-7, HGC-27 and HepG-2. Further mechanism investigation illustrated that 27d-treatment resulted in G0/G1 phase arrest and promoted apoptosis of MCF-7 cells. Compound 27d also blocked colony formation in a concentration-dependent manner in McF-7 cell lines. As the downstream-protein of BRD4, the expression of c-Myc was decreased in a dose-dependent manner after the treatment of compound 27d. Moreover, compound 27d also exhibited good in vivo and in vitro metabolic stability. All the findings meaningfully make it as a promising lead compound for further drug development.

Methylene Spacer Mediated Detection Switch Between Copper and Zinc Ions by Two Coumarin‐Pyrene Based Chemosensors

AbstractPyrene linked‐coumarin based fluorescent chemosensors L1 and L2 are utilized for the selective detection of Cu2+ and Zn2+ ions, respectively. Both chemosensors differed by a methylene spacer that connects the coumarin and pyrene rings through an imine group. The inclusion of methylene spacer dramatically changed the detection profiles of two chemosensors. While L1 showed fluorescence “turn‐off” response towards the Cu2+ ion; L2 showed “turn‐on” emission enhancement with the Zn2+ ion. Both chemosensors illustrated nano‐molar detection limits and were selective even in the presence of other competing metal ions. The 1 : 1 stoichiometry between a chemosensor and Cu2+/Zn2+ ion was supported by the binding studies, Job's plot, NMR spectral titrations, mass spectra and density functional theory (DFT) studies. The detection ability of both chemosensors was utilized by fabricating the filter paper test‐strips as well as polystyrene films for quick and visual monitoring of these ions in different water samples. Chemosensor L2 was further utilized for the “turn‐on” detection of Zn2+ ion in HepG2 cells whereas solution generated L2‐Zn species functioned as a secondary chemosensor for the detection of cystine, an important amino acid.

Design, Synthesis, Biological evaluation of Isonicotinoyl-pyrazolyl-coumarin derivatives and computational study

• A series of new Scaffold isonicotinoyl-pyrazolyl-coumarin dyads was synthesized. • The structures of the new hybrid compounds were performed by spectroscopic means. • All the compounds were screened in vitro for their potential Antifungal and Antioxidant activities. • Theoretical calculations were done for the molecules geometries. • Synthesized compounds were docked with fungal protein (Phytase A) from Aspergillus niger using AutoDock 4 software A new series of 3-(5-Hydroxy-1-isonicotinoyl-3-methyl-4,5-dihydro-1 H -pyrazol-5-yl)-2 H -chromen-2-one derivatives 3a-g was efficiently synthesized under environmentally friendly reaction conditions by reaction of 3-acetoacetylcoumarin derivatives 1a-g with isoniazid 2 . The reaction is conveniently performed at room temperature using Knorr pyrazole syntheses. The key features of this approach are its operational simplicity, the facile access to the desired products, and the good to excellent yields. The structures of the newly synthesized compounds were established by 1 H, 13 C, 2D NMR spectroscopy and mass spectrometry. 1 H- 15 N HMBC experiments were also conducted to assess the regiochemistry of final compounds. All the synthesized compounds were evaluated for their in vitro antifungal activity against both Candida albicans and Aspergillus niger strains and compared to the standard drug Ketoconazole. Among all the compounds, 3d and 3e were the most effective, showing high potential antigungal inhibitory activities with respective MIC values of 15.62 µg ml −1 for 3e against Aspergillus niger. All the newly synthesized derivatives 3a-g are evaluated for their antioxidant activity and showed good activity. SAR studies demonstrated that the presence of nitro and hydroxyl groups in the aromatic ring of the coumarin and pyrazoline rings conferred enhanced antioxidant and antifungal activity. In addition, molecular docking studies were performed for compound 3e to evaluate its potential as an inhibitor of the fungal protein (Phytase A) from Aspergillus niger and the results suggested that our isonicotinoyl-pyrazolyl-coumarin may act as promising antifungal agent.

Synthesis of Coumarin and Homoisoflavonoid Derivatives and Analogs: The Search for New Antifungal Agents.

A set of twenty-four synthetic derivatives, with coumarin and homoisoflavonoid cores and structural analogs, were submitted for evaluation of antifungal activity against various species of Candida. The broth microdilution test was used to determine the Minimum Inhibitory Concentration (MIC) of the compounds and to verify the possible antifungal action mechanisms. The synthetic derivatives were obtained using various reaction methods, and six new compounds were obtained. The structures of the synthesized products were characterized by FTIR spectroscopy: 1H-NMR, 13C-NMR, and HRMS. The coumarin derivative 8 presented the best antifungal profile, suggesting that the pentyloxy substituent at the C-7 position of coumarin ring could potentiate the bioactivity. Compound 8 was then evaluated against the biofilm of C. tropicalis ATCC 13803, which showed a statistically significant reduction in biofilm at concentrations of 0.268 µmol/mL and 0.067 µmol/mL, when compared to the growth control group. For a better understanding of their antifungal activity, compounds 8 and 21 were submitted to a study of the mode of action on the fungal cell wall and plasma membrane. It was observed that neither compound interacted directly with ergosterol present in the fungal plasma membrane or with the fungal cell wall. This suggests that their bioactivity was due to interaction involving other pharmacological targets. Compound 8 was also subjected to a molecular modeling study, which showed that its antifungal action mechanism occurred mainly through interference in the redox balance of the fungal cell, and by compromising the plasma membrane; not by direct interaction, but by interference in ergosterol synthesis. Another important finding was the antifungal capacity of homoisoflavonoids 23 and 24. Derivative 23 presented slightly higher antifungal activity, possibly due to the presence of the methoxyl substituent in the meta position in ring B.

New antimalarials identified by a cell-based phenotypic approach: Structure–activity relationships of 2,3,4,9-tetrahydro-1H-β-carboline derivatives possessing a 2-((coumarin-5-yl)oxy)alkanoyl moiety

The identification, structure–activity relationships (SARs), and biological effects of new antimalarials consisting of a 2,3,4,9-tetrahydro-1H-β-carboline core, a coumarin ring, and an oxyalkanoyl linker are described. A cell-based phenotypic approach was employed in this search for novel antimalarial drugs with unique modes of action. Our screening campaign of the RIKEN compound library succeeded in the identification of the known tetrahydro-β-carboline derivative (4e) as a hit compound showing significant in vitro activity. SAR studies on this chemical series led to the discovery of compound 4h having a (R)-methyl group on the oxyacetyl linker with potent inhibition of parasite growth (IC50 = 2.0 nM). Compound 4h was also found to exhibit significant in vivo antimalarial effects in mouse models. Furthermore, molecular modeling studies on 4e, 4h, and its diastereomer (4j) suggested that the (R)-methyl group of 4h forces the preferential adoption of a specific conformer which is considered to be an active conformer.

Access to Highly Strained Tricyclic Ketals Derived from Coumarins.

Synthesis of highly strained fused substituted dihydrobenzopyran cyclopropyl lactones derived from coumarin carboxylates are reported. The substrate scope tolerates a variety of 6- and 8-substituents on the coumarin ring. Substitution at the 5- or 7-position is resistant to tricyclic lactone formation except with 7-methyl substitution. Benzamide-containing coumarins afford the tricyclic ketal. A plausible mechanism is proposed for the formation of the fused lactone: intramolecular rearrangement of trans cyclopropyl methyl ketones with phenolic acetate via the formation of a hemiacetal.

Design, synthesis, and molecular modeling of coumarin derivatives as MDM2 inhibitors targeting breast cancer.

The coumarin ring was used as a central scaffold that was substituted with a variety of bioactive functional groups, for designing and synthesizing novel MDM2 inhibitors targeting breast cancer. The synthesized derivatives, 3c, 3d, 3g, 7b, 7c and 8 with IC50s ranging from 9.4 to 9.9µM were evaluated for their safety on MCF10a normal breast cell line. The compounds showed selectivity indices of 2.15, 3.85, 2.75, 1.38, 3.72 and 5.20 respectively. 7c was selected for further investigation, the compound was capable of down-regulating MDM2 and the anti-apoptosis proteins Bcl-2 and Bcl-xL, up-regulating the level of p53 and the pro-apoptosis protein BAX, causing cell cycle arrest at G2/M phase and activating Caspase-9 to induce apoptosis. Molecular docking study revealed the capability of derivative 7c to interact with the key amino acids in p53 binding pocket of MDM2 protein. Moreover, the physicochemical properties of compound 7c were studied in silico.

New organoruthenium(II) complexes containing N, X-donor (X = O, S) heterocyclic chelators: Synthesis, spectral characterization, in vitro cytotoxicity and apoptosis investigation

Four Schiff base ligands namely ((1E)-1-(1-(6-chloro-2-oxo-2H-chromen-3-yl) ethylidene)semicarbazide) (HL1), ((1E)-1-(1-(6-chloro-2-oxo-2H-chromen-3-yl)ethylidene thiosemicarbazide) (HL2), ((1E)-1-(1-(7-hydroxy-2-oxo-2H-chromen-3-yl)ethylidene) semicarbazide) (HL3) and ((1E)-1-(1-(7-hydroxy-2-oxo-2H-chromen-3-yl)ethylidene) thiosemicarbazide) (HL4) have been prepared, and the direct reaction of these ligands with [RuCl2(η6-p-cymene)]2 yielded the new cationic ruthenium(II) arene complexes (C I - C IV). The compounds were characterized using various spectroscopic methods. Spectroscopic analysis revealed that the ligands coordinated to ruthenium ion in a neutral bidentate fashion via N & S/O atoms. The in vitro anticancer activity of the ligands and complexes have been screened using MTT assay with two cancer cell lines, namely MCF-7 (human breast cancer cells) and A549 (human lung carcinoma). Interestingly, the cytotoxic nature of the complexes is much more potent than the standard drug cisplatin and their parent ligands with low IC50 values. The non-toxic nature of the compounds has been confirmed with human umbilical vein endothelial cells HUVEC cells. The morphological changes of the MCF-7 and A549 cells with the complexes C I- C IV have been studied by AO-EB (Acridine Orange-Ethidium Bromide) and Hoechst staining methods, and these results revealed that the complexes induced cell death only through apoptosis. The cytotoxic nature of the compounds was found to be C IV > C III > C II > C I > cisplatin > ligands. Complex C IV showed better activity due to the electron-donating hydroxyl group present in the 7th position of the coumarin ring. These results highlighted the strong possibility to develop highly active ruthenium arene complexes as anticancer agents.

Amyloidogenic immunoglobulin light chain kinetic stabilizers comprising a simple urea linker module reveal a novel binding sub-site

In immunoglobulin light chain (LC) amyloidosis, the misfolding, or misfolding and misassembly of LC a protein or fragments thereof resulting from aberrant endoproteolysis, causes organ damage to patients. A small molecule “kinetic stabilizer” drug could slow or stop these processes and improve prognosis. We previously identified coumarin-based kinetic stabilizers of LCs that can be divided into four components, including a “linker module” and “distal substructure”. Our prior studies focused on characterizing carbamate, hydantoin, and spirocyclic urea linker modules, which bind in a solvent-exposed site at the VL-VL domain interface of the LC dimer. Here, we report structure–activity relationship data on 7-diethylamino coumarin-based kinetic stabilizers. This substructure occupies the previously characterized “anchor cavity” and the “aromatic slit”. The potencies of amide and urea linker modules terminating in a variety of distal substructures attached at the 3-position of this coumarin ring were assessed. Surprisingly, crystallographic data on a 7-diethylamino coumarin-based kinetic stabilizer reveals that the urea linker module and distal substructure attached at the 3-position bind a solvent-exposed region of the full-length LC dimer distinct from previously characterized sites. Our results further elaborate the small-molecule binding surface of LCs that could be occupied by potent and selective LC kinetic stabilizers.

Design, Synthesis, Spectroscopic Characterisation and In Vitro Cytostatic Evaluation of Novel Bis(coumarin-1,2,3-triazolyl)benzenes and Hybrid Coumarin-1,2,3-triazolyl-aryl Derivatives.

In this work, a series of novel 1,2,3-triazolyl-coumarin hybrid systems were designed as potential antitumour agents. The structural modification of the coumarin ring was carried out by Cu(I)-catalysed Huisgen 1,3-dipolar cycloaddition of 7-azido-4-methylcoumarin and terminal aromatic alkynes to obtain 1,4-disubstituted 1,2,3-triazolyl-coumarin conjugates 2a–g, bis(1,2,3-triazolyl-coumarin)benzenes 2h–i and coumarin-1,2,3-triazolyl-benzazole hybrids 4a–b. The newly synthesised hybrid molecules were investigated for in vitro antitumour activity against five human cancer cell lines, colon carcinoma HCT116, breast carcinoma MCF-7, lung carcinoma H 460, human T-lymphocyte cells CEM, cervix carcinoma cells HeLa, as well as human dermal microvascular endothelial cells (HMEC-1). Most of these compounds showed moderate to pronounced cytotoxic activity, especially towards MCF-7 cell lines with IC50 = 0.3–32 μM. In addition, compounds 2a–i and 4a–b were studied by UV-Vis absorption and fluorescence spectroscopy and their basic photophysical parameters were determined.

Coumarins effectively inhibit bacterial α-carbonic anhydrases

Coumarins are known to act as prodrug inhibitors of mammalian α-carbonic anhydrases (CAs, EC 4.2.1.1) but they were not yet investigated for the inhibition of bacterial α-CAs. Here we demonstrate that such enzymes from the bacterial pathogens Neisseria gonorrhoeae (NgCAα) and Vibrio cholerae (VchCAα) are inhibited by a panel of simple coumarins incorporating hydroxyl, amino, ketone or carboxylic acid ester moieties in various positions of the ring system. The nature and the position of the substituents in the coumarin ring were the factors which strongly influenced inhibitory efficacy. NgCAα was inhibited with KIs in the range of 28.6–469.5 µM, whereas VchCAα with KIs in the range of 39.8–438.7 µM. The two human (h)CA isoforms included for comparison reason in the study, hCA I and II, were less prone to inhibition by these compounds, with KIs of 137–948.9 µM for hCA I and of 296.5–961.2 µM for hCA II, respectively. These findings are relevant for discovering coumarin bacterial CA inhibitors with selectivity for the bacterial over human isoform, with potential applications as novel antibacterial agents.

Regioselective Synthesis of Some Novel Phosphonopyrazole, Phosphonopyrimidine and Phosphonodiazepine Compounds Containing Coumarin Ring

Regioselective Synthesis of Some Novel Phosphonopyrazole, Phosphonopyrimidine and Phosphonodiazepine Compounds Containing Coumarin Ring