Coumarin-based drugs: a patent review (2008 -- present)

The Coumarin Derivative 5'-Hydroxy Auraptene Suppresses Osteoclast Differentiation via Inhibiting MAPK and c-Fos/NFATc1 Pathways

The phytochemical substances, coumarin derivatives, have demonstrated antiresorptive bone effects by suppressing osteoclast differentiation in vitro and in vivo. Recently, we have identified 5′-hydroxy auraptene (5′-HA), a coumarin derivative isolated from Lotus lalambensis Schweinf, as a novel stimulator for osteoblast differentiation. In this study, we investigated the effect of 5′-HA on osteoclast differentiation of mouse bone marrow (BM) cells. The effect of 5′-HA on BM cell proliferation and osteoclast differentiation was determined by measuring cell viability and tartrate-resistant acid phosphatase (TRAP) enzyme activity, quantification of TRAP⁺ multinucleated cells (TRAP⁺MNCs), and quantitative real-time PCR (qPCR) of osteoclastic gene expression. Regulation of NF-κB, c-Fos/NFATc1, and MAPK signaling pathways by 5′-HA during osteoclastogenesis was measured by the NF-κB reporter assay and Western blot analysis. 5′-HA significantly suppresses the receptor activator of NF-κB ligand (RANKL) induced osteoclast differentiation of BM cells in a dose-dependent manner. Consistently, treatment of BM cells with 5′-HA significantly inhibited RANKL-induced activation of NF-κB and c-Fos/NFATc1 pathways in a dose-dependent manner. Furthermore, RANKL-induced phosphorylation of ERK1/2, p-38, and JNK was significantly inhibited by 5′-HA in BM cells. In conclusion, we identified 5′-HA as a novel coumarin derivative that suppresses RANKL-induced osteoclastogenesis via inhibiting c-Fos/NFATc1 and MAPK signaling pathways.

Therapeutic potential of coumarin bearing metal complexes: Where are we headed?

The successfully application of some metallodrugs such as salvarsan, silver sulfadiazine and cisplatin in modern medicine launched the biological investigation of organometallic and metal-organic complexes. The availability and tunability of various ligands including N-heterocycles, phosphines, N-heterocyclic carbenes present an extended research area to chemists. In recent years, the preparation of the metal complexes of bioactive organic compounds is a new strategy. Coumarin derivatives are one of the classes of compounds used for this purpose, and many complexes of coumarin derivatives were prepared for enhanced biological activity, especially anticancer and antimicrobial. In this paper, we discuss the current situation of this topic.

Medicinal plants: Adjunct treatment to tuberculosis chemotherapy to prevent hepatic damage

The effectiveness of herbs for the management of chemically induced hepatotoxicity has been discussed by many researchers. However, there is a paucity of compressive literature on the significance of hepatoprotective plants for the management of anti-TB drug induced toxicity. Anti-TB drugs have been reported to causes hepatic damage, due to which, many patients across the globe discontinued the treatment. Medicinal plants have multiple therapeutic effects. The assessment of biological activity of plants against Mycobacterium and its use for hepatic recovery provides an effective treatment approach. Traditionally used medicinal plants are the rich source of phytochemicals and secondary metabolites. These compounds can restore normal function, enzymatic activity and structure of hepatic cells against anti-TB drug induced hepatotoxicity. The present review covers comprehensive details on different hepatoprotective and antimycobacterial plants studied during past few decades so that potential adjuvants can be studied for Tuberculosis chemotherapy.

Coumarins: antifungal effectiveness and future therapeutic scope

The antifungals that are in current clinical practice have a high occurrence of a side effect and multidrug resistance (MDR). Researchers across the globe are trying to develop a suitable antifungal that has minimum side effect as well as no MDR issues. Due to serious undesired effects connected with individual antifungals, it is now necessary to introduce novel and effective drugs having numerous potentials to regulate complex therapeutic targets of several fungal infections simultaneously. Thus, by taking a lead from this subject, synthesis of potent antifungals from coumarin moiety could contribute to the development of promising antifungal. Its resemblance and structural diversity make it possible to produce an auspicious antifungal candidate. Due to the natural origin of coumarin, its presence in diversity, and their broad spectrum of pharmacological activities, it secures an important place for the researcher to investigate and develop it as a promising antifungal in future. This manuscript discusses the bioavailability of coumarin (natural secondary metabolic molecule) that has privileged scaffold for many mycologists to develop it as a broad-spectrum antifungal against several opportunistic mycoses. As a result, several different kinds of coumarin derivatives were synthesized and their antifungal properties were evaluated. This review compiles various coumarin derivatives broadly investigated for antifungal activities to understand its current status and future therapeutic scope in antifungal therapy.

4,8-Dimethylcoumarin Inhibitors of Intestinal Anion Exchanger slc26a3 (Downregulated in Adenoma) for Anti-Absorptive Therapy of Constipation

The chloride/bicarbonate exchanger SLC26A3 (downregulated in adenoma) is expressed mainly in colonic epithelium, where it dehydrates the stool by facilitating the final step of chloride and fluid absorption. SLC26A3 inhibition has predicted efficacy in various types of constipation including that associated with cystic fibrosis. We previously identified, by high-throughput screening, 4,8-dimethylcoumarin inhibitors of murine slc26a3 with IC50 down to ∼150 nM. Here, we synthesized a focused library of forty-three 4,8-dimethylcoumarin analogues. Structure-activity studies revealed the requirement of 4,8-dimethylcoumarin-3-acetic acid for activity. The most potent inhibitors were produced by replacements at C7, including 3-iodo- (4az) and 3-trifluoromethyl- (4be), with IC50 of 40 and 25 nM, respectively. Pharmacokinetics in mice showed predicted therapeutic concentrations of 4az for >72 h following a single 10 mg/kg oral dose. 4az at 10 mg/kg fully normalized stool water content in a loperamide-induced mouse model of constipation. The favorable inhibition potency, selectivity within the SLC26 family, and pharmacological properties of 4az support its further preclinical development.

Coumarin tethered cyclic imides as efficacious glucose uptake agents and investigation of hit candidate to probe its binding mechanism with human serum albumin

A series of novel coumarin-cyclic imide conjugates (1a-1j) were designed and synthesized to evaluate their glucose uptake activity by insulin resistant liver hepatocyte carcinoma (HepG2) cells through 2-NBDG uptake assay. Compounds (1a-1j) were characterised using various analytical methods such as ¹H NMR, ¹³C NMR, IR, GC-MS, elemental and single-crystal X-ray diffraction techniques. Compounds (1a-1j) exhibited 85.21 - 65.80% of glucose uptake and showed low level of cytotoxicity towards human embryonic kidney cells (HEK-293) indicating good selectivity and safety profile. Compound 1f was identified as a hit candidate exhibiting 85.21% of glucose uptake which was comparable with standard antidiabetic drug Metformin (93.25% glucose uptake). Solution stability study under physiological pH conditions ≈ (3.4 - 8.7), indicates that compound 1f is sufficiently stable at varied pH conditions and thereby compatible with bio-physiological environments. Interaction of 1f with human serum albumin (HSA) were also studied which quantifies that compound 1f binds with HSA efficiently through facile binding reaction in solution. Fluorescence, UV-vis spectrophotometry and molecular modeling methodologies were employed for studying the interaction mechanism of compound 1f with protein.

FtsZ inhibitors as a new genera of antibacterial agents

The continuous emergence and rapid spread of a multidrug-resistant strain of bacterial pathogens have demanded the discovery and development of new antibacterial agents. A highly conserved prokaryotic cell division protein FtsZ is considered as a promising target by inhibiting bacterial cytokinesis. Inhibition of FtsZ assembly restrains the cell-division complex known as divisome, which results in filamentation, leading to lysis of the cell. This review focuses on details relating to the structure, function, and influence of FtsZ in bacterial cytokinesis. It also summarizes on the recent perspective of the known natural and synthetic inhibitors directly acting on FtsZ protein, with prominent antibacterial activities. A series of benzamides, trisubstituted benzimidazoles, isoquinolene, guanine nucleotides, zantrins, carbonylpyridine, 4 and 5-Substituted 1-phenyl naphthalenes, sulindac, vanillin analogues were studied here and recognized as FtsZ inhibitors that act either by disturbing FtsZ polymerization and/or GTPase activity. Doxorubicin, from a U.S. FDA, approved drug library displayed strong interaction with FtsZ. Several of the molecules discussed, include the prodrugs of benzamide based compound PC190723 (TXA-709 and TXA707). These molecules have exhibited the most prominent antibacterial activity against several strains of Staphylococcus aureus with minimal toxicity and good pharmacokinetics properties. The evidence of research reports and patent documentations on FtsZ protein has disclosed distinct support in the field of antibacterial drug discovery. The pressing need and interest shall facilitate the discovery of novel clinical molecules targeting FtsZ in the upcoming days.

5'-hydroxy Auraptene stimulates osteoblast differentiation of bone marrow-derived mesenchymal stem cells via a BMP-dependent mechanism

Background

Identifying bone anabolic agents is a superior strategy for the treatment of osteoporosis. Naturally, derived coumarin derivatives have shown osteoanabolic effect in vitro and in vivo. In this study, we investigated the effect of 5′-Hydroxy Auraptene (5′-HA), a coumarin derivative that newly isolated from Lotus lalambensis Schweinf on the differentiation of the mouse bone marrow-derived mesenchymal (skeletal) stem cells (mBMSCs) into osteoblast and adipocyte.

Methods

The effect of 5′-HA on mBMSCs cell proliferation and osteoblast differentiation was assessed by measuring cell viability, quantitative alkaline phosphatase (ALP) activity assay, Alizarin red staining for matrix mineralization and osteogenic gene array expression. Adipogenesis was measured by Oil Red O staining and quantitative real time PCR (qPCR) analysis of adipogenic markers. Regulation of BMPs signaling pathways by 5′-HA was measured by Western blot analysis and qPCR.

Results

5′-HA showed to stimulate the differentiation of mBMSCs into osteogenic cell lineage in a dose-dependent manner, without affecting their differentiation into adipocytic cell lineage. Treatment of mBMSCs with 5′-HA showed to promote significantly the BMP2-induced osteogenesis in mBMSCs via activating Smad1/5/8 phosphorylation and increasing Smad4 expression. Blocking of BMP signaling using BMPR1 selective inhibitor LDN-193189 significantly inhibited the stimulatory effect of 5′-HA on osteogenesis.

Conclusions

Our data identified 5′-HA, as a novel coumarin derivative that function to stimulate the differentiation of mBMSCs into osteoblasts in BMP-signaling dependent mechanism.

Electronic supplementary material

The online version of this article (10.1186/s12929-019-0544-7) contains supplementary material, which is available to authorized users.

Heterogeneously Catalyzed Pechmann Condensation Employing the Tailored Zn0.925Ti0.075O NPs: Synthesis of Coumarin

A novel heterogeneous catalytic method was developed for the synthesis of coumarin and its derivatives using the Ti(IV)-doped ZnO matrix forming catalyst Zn_0.925Ti_0.075O having a high surface area and good Lewis acidity. The catalyst shows high activity toward a broad spectrum of the substituted phenols with β-ketoesters such as ethyl acetoacetate, ethyl butyryl acetate, ethyl benzoyl acetate, and so forth in good yields over short reaction times during the synthesis of coumarins. The methodology was further extended for the synthesis of ayapin molecules. The catalyst also shows recycle activity up to seven cycles with very good stability.

Building Molecular Complexity from Quinizarin: Conjoined Coumarins and Coronene Analogs

The double Knoevenagel condensation of 1,4-dibenzoyloxyanthraquinone with methyl esters of arylacetic acids affords a series of compounds based upon a previously unknown 1,8-dioxa-benzo[e]pyrene-2,7-dione heterocyclic core. The aryl groups incorporated in the 3- and 6-positions can be oxidatively coupled to the π-expanded backbone to produce a further new heterocyclic core: 1,10-dioxa-dibenzo[dj]coronene-2,9-dione. The intriguing optical properties of these π-expanded coumarin derivatives are discussed and rationalized through quantum chemical calculations. The broad absorption bands of 1,8-dioxa-benzo[e]pyrene-2,7-dione-based dyes are attributed to both HOMO-1→LUMO and HOMO→LUMO transitions, which have a similar energy. Weakly coupled electron-donating aryl substituents result in a moderate bathochromic shift of both the absorption and emission by 30-60 nm in toluene. The emissive properties of these compounds are in part determined by the oscillator strength of the main transition, lifetimes of the excited state, and by the energy match of the excited state with a triplet state of a similar energy. The 1,10-dioxa-dibenzo[dj]coronene-2,9-dione displays a much smaller Stokes shift, yet a markedly increased fluorescence quantum yield of 90 % owing to the increased rigidity compared with the 1,8-dioxa-benzo[e]pyrene-2,7-dione core.

QBMG: quasi-biogenic molecule generator with deep recurrent neural network

Biogenic compounds are important materials for drug discovery and chemical biology. In this work, we report a quasi-biogenic molecule generator (QBMG) to compose virtual quasi-biogenic compound libraries by means of gated recurrent unit recurrent neural networks. The library includes stereo-chemical properties, which are crucial features of natural products. QMBG can reproduce the property distribution of the underlying training set, while being able to generate realistic, novel molecules outside of the training set. Furthermore, these compounds are associated with known bioactivities. A focused compound library based on a given chemotype/scaffold can also be generated by this approach combining transfer learning technology. This approach can be used to generate virtual compound libraries for pharmaceutical lead identification and optimization.

Direct C-3 alkylation of coumarins via decarboxylative coupling with carboxylic acids

A metal-free direct alkylation of coumarins using carboxylic acids in aqueous media with a broad substrate scope is devised.

Synthesis of Novel 1,2,4-Triazolyl Coumarin Derivatives as Potential Anticancer Agents

A series of novel coumarin derivatives carrying 1,2,4-triazole or 1,2,4-triazolo[3,4-b][1,3,4]thiadiazole moieties were prepared and evaluated in vitro as anticancer in the human colon cancer (HCT116) cell line. The derivatives 4c and 8c exhibited marked anticancer activity with IC50 values 4.363 and 2.656 µM, respectively. The molecular docking studies suggested possible interaction with tyrosine kinases (CDK2).

Heterocoumarins Are Selective Carbonic Anhydrase IX and XII Inhibitors with Cytotoxic Effects against Cancer Cells Lines

We have synthesized a new series of coumarin-based compounds demonstrating high selectivity and potent effects with low nanomolar affinity against the tumor associated carbonic anhydrase (CA, EC 4.2.1.1) isoforms hCA IX and XII. A number of these compounds were evaluated ex vivo against human prostate (PC3) and breast (MDA-MB-231) cancer cell lines. Compounds 4b and 15 revealed effective cytotoxic effects after 48 h of incubation in both normoxic and hypoxic conditions with PC3 cancer cell line. However, compound 3 showed selective cytotoxic effects against MDA-MB-231 in hypoxic condition. These results may be of particular importance for the choice of future drug candidates targeting hypoxic tumors and metastases, considering the fact that a selective carbonic anhydrase CA IX inhibitor (SLC-0111) is presently in phase II clinical trials.

Photophysical properties and photodynamic anti-tumor activity of corrole-coumarin dyads

A new non-conjugated corrole-coumarin dyad and its gallium complex has been synthesized. Photophysical properties of the dyads were tested in two solvents, exhibiting strong solvent effect on the absorption and fluorescence spectra. Absorption spectra of the dyads are a linear combination of the spectra of their corresponding monomers, demonstrating a negligible electronic communication between coumarin and corrole moiety. However, fluorescence emission of coumarin entity in all dyads were quenched significantly as compared to pristine coumarin; this was attributed to intramolecular energy transfer from coumarin to the corrole. Photodynamic anti-tumor tests revealed that gallium corrole-coumarin dyads (2-Ga) exhibited good PDT activity towards SiHa cells. After PDT treatment, 2-Ga could induce apoptosis in SiHa cells, which was associated to cell S phase arrest, collapse of the mitochondrial membrane potential and increase of the intracellular ROS level.

One-pot synthesis, biological evaluation and molecular docking studies of fused thiazolo[2,3-b]pyrimidinone-pyrazolylcoumarin hybrids

As a part of our endeavor toward the synthesis of a new class of biologically potent heterocyclic hybrids, a series of newly fused thiazolo[2,3-b]pyrimidinones bearing a pyrazolylcoumarin moiety (6a-p) were synthesized in acceptable yields. Anticipated structures of all titled compounds were in agreement with spectral and analytical (C, H and N) analyses. The compounds were screened for in vitro antibacterial activity against both G⁺ and G^- bacterial strains and antiproliferative activity against K562 (chronic myelogenous leukemia), MCF-7 (breast cancer), MDA-MB-231 (breast cancer), COLO 205 (colorectal adenocarcinoma), HepG2 (hepatocellular carcinoma) cell lines. Further, potent antibacterial compounds were subjected to molecular docking studies in order to gain insight into their plausible binding modes and mechanism of action against MurB. The modeling results were in agreement with the experimental data.

Synthesis and evaluation of novel coumarin-oxime ethers as potential anti-tubercular agents: Their DNA cleavage ability and BSA interaction study

As a contribution to the development of novel coumarin-oxime ether conjugates with therapeutically interesting properties, a series of coumarin-oxime ether (1a-1j) was synthesised using S_N2 reaction of bromomethyl coumarins with butane-2,3-dione monoxime. Invitro anti-tuberculosis activityagainstMTBH₃₇Rv strain was established for the coumarin-oxime ether (1a-1j). Most of the compounds exhibited significant activity with minimum inhibitory concentration (MIC)in the range of 0.04-3.12 μg mL^-1. Compound (1h) was identified as a hit candidate exhibiting MIC of 0.04 μg mL^-1, closer to the MIC value of Isoniazid (0.02 μg mL^-1), a commercially available drug for the treatment of tuberculosis. Compound 1h also displayed a low level of toxicity in Vero cells along with a good safety profile in vitro. Compounds that showed potent anti-tubercular activity were also found to cleave DNA more efficiently and thereby exhibit nuclease activity. The most active compound (1h) was further studied to deduce the mode of interaction with model serum protein, bovine serum albumin (BSA).

Imidazolium and benzimidazolium-containing compounds: from simple toxic salts to highly bioactive drugs

The toxicity of simple imidazolium and benzimidazolium salts started to be more and more investigated in the last few years and was taken in consideration in the context of microorganisms, plants and more evolved organisms' exposure. However, the toxicity of these salts can be exploited in the development of different biological applications by incorporating them in the structure of compounds that specifically target microorganisms and cancer cells. We highlight in this minireview the way researchers became aware of the inherent problem of the stability and bioaccumulation of imidazolium and benzimidazolium salts and how they found inspiration to exploit their toxicity by incorporating them into new highly potent drugs.

Coumarin derivatives: an updated patent review (2015-2016)

INTRODUCTION

Coumarins belong to the benzopyrone family. They are naturally plant-derived or synthetically obtained substances, presenting a wide variety of biological activities, offering an extented therapeutic profile. Their structural characteristics correlated to physicochemical properties define their pleiotropic biological responses.

AREAS COVERED IN THIS REVIEW

Recent patent publications (2015-2016), describing coumarins and their derivatives are analyzed. Synthesis, biological evaluations in vitro /in vivo e.g. antiviral, anticancer, cytotoxic, antioxidant, anti-inflammmatory protocols are included. Furthermore, several pharmaceutical applications and pharmaceutical compositions are also described. Expert opinion: Several synthetic coumarins, hybrids and derivatives (azoles, sulfonyl, furazan, pyrazole etc) have been found to possess promising anticancer, antitumor anti-proliferative activities. Their clinical evaluation will be critical to assess therapeutic utility. The compounds for which the mechanism of action is well defined can serve as lead compounds for the design of new more potent molecules.

Acetamide Derivatives of Chromen-2-ones as Potent Cholinesterase Inhibitors

Alzheimer's disease (AD), a neurodegenerative disorder, is a serious medical issue worldwide with drastic social consequences. Inhibition of cholinesterase is one of the rational and effective approaches to retard the symptoms of AD and, hence, consistent efforts are being made to develop efficient anti-cholinesterase agents. In pursuit of this, a series of 19 acetamide derivatives of chromen-2-ones were synthesized and evaluated for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potential. All the synthesized compounds exhibited significant anti-AChE and anti-BChE activity, with IC₅₀ values in the range of 0.24-10.19 μM and 0.64-30.08 μM, respectively, using donepezil hydrochloride as the standard. Out of 19 compounds screened, 3 compounds, viz. 22, 40, and 43, caused 50% inhibition of AChE at 0.24, 0.25, and 0.25 μM, respectively. A kinetic study revealed them to be mixed-type inhibitors, binding with both the CAS and PAS sites of AChE. The above-selected compounds were found to be effective inhibitors of AChE-induced and self-mediated Aβ_1-42 aggregation. ADMET predictions demonstrated that these compounds may possess suitable blood-brain barrier (BBB) permeability. Hemolytic assay results revealed that these compounds did not lyse human RBCs up to a thousand times of their IC₅₀ value. MTT assays performed for the shortlisted compounds showed them to be negligibly toxic after 24 h of treatment with the SH-SY5Y neuroblastoma cells. These results provide insights for further optimization of the scaffolds for designing the next generation of compounds as lead cholinesterase inhibitors.

Synthesis of nanoparticles based on PDMMLA derivative copolymers and study of warfarin encapsulation and controlled release

The warfarin encapsulation by new biodegradable nanoparticles based on PDMMLA and its controlled release were studied for the first time.

Total syntheses of gerberinol I and the pterophyllins 2 and 4 using the Casnati–Skattebøl reaction under different conditions

The total syntheses of the title compounds were achieved from a single coumarin precursor, taking advantage of the temperature-dependent divergent outcomes of the Casnati–Skattebøl reaction.

The effect of chalcogen substitution on the structure and spectroscopy of 4,7-dimethyl-2H-chromen-2-one/thione analogues

The structural and spectroscopic properties of the 1-benzopyran-2-one/thione moiety.

Theoretical study of optical activity of 1:1 hydrogen bond complexes of water with S-warfarin

The molecular interaction between S-warfarin (SW) and a single water molecule was investigated using the B3LYP method at 6-311++G(d,p) basis set. The vibrational spectra of the optimized complexes have been investigated for stabilization checking. Quantum theories of atoms in molecules, natural bond orbitals, molecular electrostatic potentials and energy decomposition analysis methods have been applied to analyze the intermolecular interactions. The intermolecular charge transfer in the most stable complex is in the opposite direction from those in the other complexes. The optical spectra and the hyperpolarizabilities of SW-water hydrogen bond complexes have been computed.

Novel synthetic chalcones induce apoptosis in the A549 non-small cell lung cancer cells harboring a KRAS mutation

A series of novel chalcones were synthesized by the Claisen-Schmidt condensation reaction of tetralones and 5-/6-indolecarboxaldehydes. Treatment of human lung cancer cell line harboring KRAS mutation (A549) with the chalcones induced dose-dependent apoptosis. Cell cycle analyses and Western blotting suggested the critical role of the chalcones in interrupting G2/M transition of cell cycle. SAR study demonstrated that substituent on the indole N atom significantly affects the anticancer activity of the chalcones, with methyl and ethyl providing the more active compounds (EC₅₀: 110-200nM), Compound 1g was found to be >4-fold more active in the A549 cells (EC₅₀: 110nM) than in prostate (PC3) or pancreatic cancer (CLR2119, PAN02) cells. Furthermore, compound 1l selectively induced apoptosis of lung cancer cells A549 (EC₅₀: 0.55μM) but did not show measurable toxicity in the normal lung bronchial epithelial cells (hBEC) at doses as high as 10μM, indicating specificity towards cancer cells.

Highly enantioselective synthesis of dihydrocoumarin-fused dihydropyrans via the phosphine-catalyzed [4 + 2] annulation of allenones with 3-aroylcoumarins

Phosphine-catalyzed [4 + 2] annulation between 3-aroylcoumarins and allenones has been developed. In the presence of a dipeptide phosphine catalyst 7, dihydrocoumarin-fused dihydropyrans were prepared in high yields and with excellent enantioselectivities.

Triazole tethered C5-curcuminoid-coumarin based molecular hybrids as novel antitubulin agents: Design, synthesis, biological investigation and docking studies

Keeping in view the confines allied with presently accessible antitumor agents and success of C5-curcuminoid based bifunctional hybrids as novel antitubulin agnets, molecular hybrids of C5-curcuminoid and coumarin tethered by triazole ring have been synthesized and investigated for in-vitro cytotoxicity against THP-1, COLO-205, HCT-116 and PC-3 human tumor cell lines. The results revealed that the compounds A-2 to A-9, B-2, B-3, B-7 showed significant cytotoxic potential against THP-1, COLO-205 and HCT-116 cell lines, while the PC-3 cell line among these was found to be almost resistant. Structure activity relationship revealed that the nature of Ring X and the length of carbon-bridge (n) connecting triazole ring with coumarin moiety considerably influence the activity. Methoxy substituted phenyl ring as Ring X and two carbon-bridges were found to be the ideal structural features. The most potent compounds (A-2, A-3 and A-7) were further tested for tubulin polymerization inhibition. Compound A-2 was found to significantly inhibit the tubulin polymerization (IC50 = 0.82 μM in THP-1 tumor cells). The significant cytotoxicity and tubulin polymerization inhibition by A-2 was further rationalized by docking studies where it was docked at the curcumin binding site of tubulin.

Anti-Neuroinflammatory Effect of MC13, a Novel Coumarin Compound From Condiment Murraya, Through Inhibiting Lipopolysaccharide-Induced TRAF6-TAK1-NF-κB, P38/ERK MAPKS and Jak2-Stat1/Stat3 Pathways

MC13 is a novel coumarin compound found in Murraya, an economic crop whose leaves are widely used as condiment (curry) in cuisine. The aims of the present study were to investigate the neuroprotective effects of MC13 on microglia-mediated inflammatory injury model as well as potential molecular mechanism. Cell viability and apoptosis assay demonstrated that MC13 was not toxic to neurons and significantly protected neurons from microglia-mediated inflammatory injury upon lipopolysaccharide (LPS) stimulation. Results showed that MC13 markedly inhibited LPS-induced production of various inflammatory mediators, including nitrite oxide (Griess method), TNF-α and IL-6 (ELISA assay) in a concentration-dependent manner. Mechanism study showed that MC13 could suppress the activation of NF-κB, which was the central regulator for inflammatory response, and also decreased the interaction of TGF-β-activated kinase 1 (TAK1)-binding protein (TAB2) with TAK1 and TNF receptor associated factor (TRAF6), leading to the decreased phosphorylation levels of NF-κB upstream regulators such as IκB and IκB kinase (IKK). MC13 also significantly down-regulated the phosphorylation levels of ERK and p38 MAPKs, which played key roles in microglia-mediated inflammatory response. Furthermore, MC13 inhibited Jak2-dependent Stat1/3 signaling pathway activation by blocking Jak2 phosphorylation, Stat1/3 phosphorylation, and nuclear translocation. Taken together, our results demonstrated that MC13 protected neurons from microglia-mediated neuroinflammatory injury by inhibiting TRAF6-TAK1-NF-κB, p38/ERK MAPKs, and Jak2-Stat1/3 pathways. Finally, MC13 might interact with LPS and interfere LPS-binding to cell membrane surface. These findings suggested that coumarin might act as a potential medicinal agent for treating neuroinflammation as well as inflammation-related neurodegenerative diseases.

Coumarin-based thiosemicarbazones as potent urease inhibitors: synthesis, solid state self-assembly and molecular docking

A series of coumarin-based thiosemicarbazones and their metal complexes have been synthesized and their in vitro potency against urease was evaluated.

Implication of coumarins towards central nervous system disorders

Coumarins are widely distributed, plant-derived, 2H-1-benzopyran-2-one derivatives which have attracted intense interest in recent years as a result of their diverse and potent pharmacological properties. Particularly, their effects on the central nervous system (CNS) have been established. The present review discusses the most important pharmacological effects of natural and synthetic coumarins on the CNS, including their interactions with benzodiazepine receptors, their dopaminergic and serotonergic affinity, and their ability to inhibit cholinesterases and monoamine oxidases. The structure-activity relationships pertaining to these effects are also discussed. This review posits that natural or synthetic coumarins have the potential for development in the therapy of psychiatric and neurodegenerative disorders, including Alzheimer's and Parkinson's diseases, schizophrenia, anxiety, epilepsy, and depression.

Heterocyclic Anticancer Compounds: Recent Advances and the Paradigm Shift towards the Use of Nanomedicine's Tool Box

The majority of heterocycle compounds and typically common heterocycle fragments present in most pharmaceuticals currently marketed, alongside with their intrinsic versatility and unique physicochemical properties, have poised them as true cornerstones of medicinal chemistry. Apart from the already marketed drugs, there are many other being investigated for their promising activity against several malignancies. In particular, anticancer research has been capitalizing on the intrinsic versatility and dynamic core scaffold of these compounds. Nevertheless, as for any other promising anticancer drugs, heterocyclic compounds do not come without shortcomings. In this review, we provide for a concise overview of heterocyclic active compounds and families and their main applications in medicine. We shall focus on those suitable for cancer therapy while simultaneously addressing main biochemical modes of action, biological targets, structure-activity relationships as well as intrinsic limitation issues in the use of these compounds. Finally, considering the advent of nanotechnology for effective selective targeting of drugs, we shall discuss fundamental aspects and considerations on nanovectorization of such compounds that may improve pharmacokinetic/pharmacodynamic properties of heterocycles.

Coumarin: A Privileged Scaffold for the Design and Development of Antineurodegenerative Agents

Drug development for neurodegenerative diseases (NDs) is foremost task for the medicinal chemists in the 21st century. Coumarins are exemplary of an assorted and aptitudinally useful set of drugs. Coumarins play a momentous role in several pharmacological and medicinal aspects. Its analogues are anticipated to play a significant role in the development of new therapeutic leads for NDs. Their promising applications in the field of ND medication are exemplified by clinical candidates such as nodakenin that have been potent for demoting memory impairment. Apart from ND, clinically used anticoagulant warfarin, anticoagulant dicoumarol, and antibiotic coumermycin, novobiocin and chartesium grab the interest of researchers in coumarins. It would be worthwhile to look at the different biological processes that could cause neurodegeneration, thereby establishing a link with distinct coumarin derivatives to serve the purpose of medication. This review undertakes estimation of the wide spectrum of studies focusing coumarin to the domain of drug research for ND. Herein, we search for multitarget coumarin-based inhibitors and their scope for NDs. Future challenges in coumarin-based drug development have been discussed, and emphases have been laid on the future perspectives of coumarins as possible drugs in the future for the treatment of NDs.