Discovery and synthesis of novel substituted benzocoumarins as orally active lipid modulating agents

Synthesis, molecular modelling and evaluation of larvicidal efficacy of annulated Benzo[h]chromenes against Culex pipiens L. Larvae

A new series of substituted benzo[h]chromene, benzochromenopyrimidine, and benzochromenotriazolopyrimidine derivatives were synthesized via chemical transformations of iminonitrile, ethoxymethylene amino, and cyanomethylene functionalities. The chemical structures of the synthesized compounds were assured by spectroscopic data and elemental analysis. The larvicidal efficacy of these compounds against Culex pipiens L. larvae was investigated, revealing potent insecticidal activity, particularly for compounds 6, 10, and 16, exceeding that of the standard insecticide chlorpyrifos. The mode of action of these compounds was explored through molecular docking studies, indicating their potential as acetylcholine esterase (AChE) inhibitors and nicotinic acetylcholine receptors (nAChR) blockers. The structure-activity relationship analysis highlighted the influence of substituents and fused heterocyclic rings on larvicidal potency. These findings suggest that the synthesized compounds hold promise as potential candidates for developing novel and effective mosquito control agents.

Polymer Supported Nitrogen-Bridged Symmetrical Binuclear Dioxidomolybdenum(VI) Complexes and Their Homogeneous Analogues as Potential Catalysts for Efficient Synthesis of 2-Amino-3-Cyano-4H-Chromenes/Pyrans

Reaction of 2-chloromethyl-1H-benzimidazole with known intermediates (i-iii), prepared from diaminoguanidine hydrochloride with salicylaldehyde, 5-bromosalicylaldehyde or 3,5-di-tert-butylsalicylaldehyde, in the presence of triethylamine (NEt3) led to the formation of benzimidazole appended new ligands, H4L1-H4L3 (I-III). The homogeneous nitrogen-bridged symmetrical binuclear complexes, [(MoVIO2)2(L1)(H2O)2] (1), [(MoVIO2)2(L2)(H2O)2] (2) and [(MoVIO2)2(L3)(MeOH)2] (3) have been isolated by reacting these ligands with [MoVIO2(acac)2] in a 1 : 2 molar ratio in refluxing methanol. Using 1 : 1 (ligand to Mo precursor) molar ratio under above reaction conditions resulted in the corresponding mononuclear complexes, [MoVIO2(H2L1)(MeOH)] (4), [MoVIO2(H2L2)(H2O)] (5) and [MoVIO2(H2L3)(MeOH)] (6). The binuclear heterogeneous compounds [(MoVIO2)2(L1)(DMF)2]@PS (PS-1), [(MoVIO2)2(L2)(DMF)2]@PS (PS-2) and [(MoVIO2)2(L3)(DMF)2]@PS (PS-3) have been obtained by immobilization of 1-3 onto chloromethylated polystyrene (PS) beads. All synthesized ligands, homogeneous as well as supported compounds have been characterized by elemental analyses and various spectroscopic methods. Single crystal X-ray diffraction study of complexes 1 and 3 confirms their nitrogen-bridged symmetrical binuclear structures while 4 is mononuclear. Heterogeneous compounds (PS-1-PS-3) have further been studied by microwave plasma atomic emission spectroscopy, X-ray photoelectron spectroscopy, and field emission scanning electron microscopy along with energy dispersive spectroscopy. These compounds (homogeneous and heterogeneous) were explored for catalytic applications to one-pot multicomponent reactions (MCRs) for efficient synthesis of biologically active 2-amino-3-cyano-4H-chromenes/pyrans (21 examples). Optimising various reaction parameters helped in achieving as high as 97 % yields of products. Though, only half equivalent of the binuclear complexes (1-3) was required compared to mononuclear analogues (4-6) to achieve comparable yields, heterogeneous catalysts have an added advantage due to their stability and recyclability. Suitable reaction mechanism has also been proposed based on isolated intermediates.

Discovery of benzochromene derivatives first example with dual cytotoxic activity against the resistant cancer cell MCF-7/ADR and inhibitory effect of the P-glycoprotein expression levels

A series of 1H-benzo[f]chromene moieties (4a-z) were synthesised under Ultrasonic irradiation and confirmed with spectral analyses. Derivative 4i solely possessed an X-ray single crystal. The anti-proliferative efficacy of the desired molecules has been explored against three cancer cells: MCF-7, HCT-116, and HepG-2 with the cytotoxically active derivatives screened against MCF-7/ADR and normal cells HFL-1 and WI-38. Furthermore, compounds 4b-d, 4k, 4n, 4q, and 4w, which possessed good potency against MCF-7/ADR, were tested as permeability glycoprotein (P-glycoprotein [P-gp]) expression inhibitors. The attained data confirmed that 4b-d, 4q, and 4w exhibited strong expression inhibition against the P-gp alongside its cytotoxic effect on MCF-7/ADR. The western blot results and Rho123 accumulation assays showed that compounds 4b-d, 4q, and 4w effectively inhibited the P-gp expression and efflux function. Meanwhile, 4b-d, 4q, and 4w induced apoptosis and accumulation of the treated MCF-7/ADR cells in the G1 phase and 4k and 4n in the S phase of the cell cycle.

Synthesis, Characterization, Computational Studies, Molecular Docking, and In Vitro Anticancer Activity of Dihydropyrano[3,2-c]chromene and 2-Aminobenzochromene Derivatives

2-Aminobenzochromenes and dihydropyranochromenes represent a unique class of biologically active compounds. Recent organic syntheses focus on the development of environmentally benign synthetic protocols, and as a part of this concept, we have taken a considerable interest in the synthesis of this class of biologically active compounds using an environment-friendly, reusable heterogeneous Amberlite IRA 400-Cl resin catalyst. This work further aims to highlight the importance and advantages of these compounds and to compare the experimental data obtained with those of the theoretical calculations made using the density functional theory (DFT) method. Molecular docking studies on the selected compounds were also carried out to study the effectiveness of these compounds in liver fibrosis treatment. Furthermore, we have performed molecular docking studies and an in vitro study of the anticancer activity of dihydropyrano[3,2-c]chromenes and 2-aminobenzochromenes against human colon cancer cells [HT29].

The Crystal Structure of 3-Amino-1-(4-Chlorophenyl)-9-Methoxy-1H-Benzo[f]Chromene-2-Carbonitrile: Antimicrobial Activity and Docking Studies

Compound 3-amino-1-(4-chlorophenyl)-9-methoxy-1H-benzo[f]chromene-2-carbonitrile (4), was synthesized via the reaction of 7-methoxynaphthalen-2-ol (1), 4-chlorobenzaldehyde (2), and malononitrile (3) in an ethanolic piperidine solution under microwave irradiation. The synthesized pyran derivative 4 was asserted through spectral data and X-ray diffraction. The molecular structure of compound 4 was established unambiguously through the single crystal X-ray measurements and crystallized in the Triclinic, P-1, a = 8.7171 (4) Å, b = 10.9509 (5) Å, c = 19.5853 (9) Å, α = 78.249 (2)°, β = 89.000 (2)°, γ = 70.054 (2)°, V = 1717.88 (14) Å3, Z = 4. The target molecule has been screened for antibacterial and antifungal functionality. Compound 4 exhibited favorable antimicrobial activities that resembled the reference antimicrobial agents with an IZ range of 16–26 mm. In addition, MIC, MBC, and MFC were assessed and screened for molecule 4, revealing bactericidal and fungicidal effects. Lastly, a molecular docking analysis was addressed and conducted for this desired molecule.

Synthesis, cytotoxicity and in silico study of some novel benzocoumarin-chalcone-bearing aryl ester derivatives and benzocoumarin-derived arylamide analogs

The development of new prostate cancer protein receptor cytochrome P450 17A1 inhibitors offers the possibility of generating structures of increased potency. To this end, the chalcone analogs 7 and 8 were prepared from treatment of methyl 3-oxo-3H-benzocoumarin-2-carboxylate (4) with aryl aldehydes. Treatment of 7 and 8 with three anti-inflammatory drugs, flurbiprofen, ketoprofen and ibuprofen, in the presence of POCl3/DMAP gave the ester analogs 9–12. Analogously, treatment of ethyl 3-oxo-3H-benzocoumarin-2-carboxylate (15), prepared previously from 2-hydroxy-1-naphthaldehyde (13) and dimethylmalonate (14), with various arylamines: 4-bromoaniline, 2-amino-6-methylpyridine, amino-antipyrine and 2-amino-5-nitrothiazole, in the presence of potassium tert-butoxide gave the benzocoumarine-3-arylamide analogs. The in vitro cytotoxic activities of 9–12 and 16–19 were evaluated against human prostate cancer cell lines (PC-3) and normal human liver epithelia (WRL-68) by MTT assay. Compounds 10 and 17 were the most active cytotoxic agents among the series against PC-3 cells with IC50 values of 71.35 and 78.25 μg mL–1 with SI values of 3.0 and 4.2, respectively (calculated from the cytotoxicity effects of 10 and 17 on the normal human liver epithelia [WRL-68]). Furthermore, compounds 11 and 12 were tested against breast cancer (HER2 cell lines), prostate cancer (DU-135 cell lines) and MCF-7 but were inactive. Molecular docking studies between the protein receptor CYPP450 17A1 and compounds 10 and 17 revealed that these compounds primarily form hydrophobic interactions with the receptor.

Synthesis and Evaluation of Cytotoxic Activity of Certain Benzo[h]chromene Derivatives

BACKGROUND

Benzo[h]chromenes attracted great attention because of their widespread biological activities, including anti-proliferate activity, and the discovery of novel effective anti-cancer agents is imperative.

OBJECTIVE

The main objective was to synthesize new benzo[h]chromene derivatives and some reported derivatives, and then test all of them for their anti-cancer activities.

METHODS

The structures of the newly synthesized derivatives were confirmed by elemental and spectral analysis (IR, Mass, ¹H-NMR and ¹³C-NMR). 35 compounds were selected by the National Cancer Institute (NCI) for single-dose testing against 60 cell lines and 3 active compounds were selected for 5-doses testing. Also, these 3 compounds were tested as EGFR-inhibitors; using sorafenib as standard, and as Tubulin polymerization inhibitors using colchicines as a standard drug. Moreover, molecular docking study for the most active derivative on these 2 enzymes was also carried out.

RESULTS

Compounds 1a, 1c and 2b have the highest activities among all 35 tested compounds especially compound 1c.

CONCLUSION

compound 1c has promising anti-cancer activities compared to the used standards and may need further modification and investigations.

Heteroaromatization with 4-Phenyldiazenyl-1-naphthol. Part IV: Synthesis of Some New Heterocyclic Compounds with Potential Biological Activity

BACKGROUND

Synthetic azo compounds and their derivatives have been studied extensively due to their biological and pharmacological activities. Pyranopyridines, pyranopyrimidines and tetrazoles derivatives have emerged as a promising and attractive scaffold in the development of potent biological and pharmacological agents.

OBJECTIVES

To design a series of new benzochromeno(pyridine/pyrimidine/tetrazole) derivatives and evaluate their antimicrobial activity against some bacterial strains (Gram-positive and Gram-negative) and some fungal strains.

MATERIALS AND METHODS

The (E)-7-(4-chlorophenyl)-5-(phenyldiazenyl)-10-thioxo-7,9,10,11-tetrahydro-8Hnaptho[ 1,2-b]pyrano[2,3-d]pyrimidin-8-one (4) was synthesized by the reaction of 4H-naphtho[1,2-b]pyran-3- carbonitrile (3) with carbon disulfide in alcoholic potassium hydroxide solution. Reaction of 3 with sodium azide in DMF and in presence of ammonium chloride afforded 6-(phenyldiazenyl)-3-(1H-tetrazol-5-yl)-4Hbenzo[ h]chromen-2-amine (7) while with malononitrile, thiourea or urea gave chromeno[2,3-b]pyridine-9- carbonitrile (8), chromeno[2,3-d]pyrimidine-10-thione (9) and chromeno[2,3-d]pyrimidin-10-one (10), respectively. The assignment structures were established on the basis of spectral data.

RESULTS

In this study, the antimicrobial activity of the synthesized compounds 3-12 was examined for their in vitro antimicrobial activity by using agar diffusion method such as Mueller-Hinton agar medium for bacteria and Sabouraud's agar medium for fungi. Ampicillin and mycostatine were included in the experiments as reference drugs.

CONCLUSION

A series of new benzochromeno(pyridine/pyrimidine/tetrazole) derivatives were synthesized in this work. All compounds were evaluated in antimicrobial activities.

Discovery of Substituted N-(6-Chloro-3-cyano-4-phenyl-4H-chromen-2-yl)- 2-(4-chloro-phenoxy)-acetamide for Biphasic Anticancer and Anticonvulsant Activities

BACKGROUND

Privileged 4H-chromenes possess potent anticancer and anticonvulsant activities. By the inspiring potency of 4H-chromenes and demands of the present era of scaffolds, an effective molecule was discovered for the treatment of cancer and related diseases.

OBJECTIVE

This study designed and synthesized a novel series of 4H-chromene derivatives from one-port synthesis for the treatment of cancer and other such diseases.

METHODS

A side amide chain was substituted in multiple steps on the amine group of chromene. Later, the anticancer activity of synthesized compounds was investigated against the human colon adenocarcinoma cell line (HT-29) using sulforhodamine B (SRB) assay. Moreover, anticonvulsant activity was also detected using maximal electroshock seizure (MES) model and subcutaneous Metrazol Seizure Threshold Test (scMET) in albino Wistar rats. Neurotoxicity was evaluated by using the rotarod test. Before the synthesis, docking studies were performed using various molecular targets. Subsequently, the computational study of the titled compounds was performed to predict the pharmacokinetic profile.

RESULTS

Among the fifteen tested compounds, A4 and A9 were found to be active against HT-29 cells (growth inhibitory dose 50% (GI50) <11μM). Moreover, compounds A4 showed the protection at 300mg/kg in scMET (h) for albino Wistar rats and compounds A9, A11, and A15 exhibited the anticonvulsant effect at the doses 100, 300 and 300 mg/kg, respectively in MES screen (h).

CONCLUSION

Due to these encouraging results, we concluded that both A4 and A9 may be effective for treatement against colon cancer, while compound A9 may be used as a considerable effective molecule for the treatment of epilepsy.

Design, synthesis, in vivo, and in silico evaluation of new coumarin-1,2,4-oxadiazole hybrids as anticonvulsant agents

A novel series of coumarin-1,2,4-oxadiazole hybrids were designed, synthesized, and evaluated as anticonvulsant agents. The title compounds were easily synthesized from reaction of appropriate coumarins and 3-aryl-5-(chloromethyl)-1,2,4-oxadiazole derivatives. In vivo anticonvulsant activity of the synthesized compounds were determined using pentylenetetrazole (PTZ)- and maximal electroshock (MES)-induced seizures confirming that they were more effective against MES test than PTZ test. It should be noted that compounds 3b, 3c, and 3e showed the best activity in MES model which possessed drug-like properties with no neurotoxicity. Anticonvulsant activity of the most potent compound 3b was remarkably reduced after treatment with flumazenil which confirmed the participation of a benzodiazepine mechanism in the anticonvulsant activity. Also, docking study of compound 3b in the BZD-binding site of GABA_A receptor confirmed possible binding of 3b to the BZD receptors.

Design and Synthesis of Novel Heterocyclic-Based 4H-benzo[h]chromene Moieties: Targeting Antitumor Caspase 3/7 Activities and Cell Cycle Analysis

Novel fused chromenes (4,7–11) and pyrimidines (12–16) were designed, synthesized, and evaluated for their mammary gland breast cancer (MCF-7), human colon cancer (HCT-116), and liver cancer (HepG-2) activities. The structural identity of the synthesized compounds was established according to their spectroscopic analysis, such as FT-IR, NMR, and mass spectroscopy. The preliminary results of the bioassay disclosed that some of the target compounds were proven to have a significant antiproliferative effect against the three cell lines, as compared to Doxorubicin, Vinblastine, and Colchicine, used as reference drugs. Particularly, compounds 7 and 14 exerted promising anticancer activity towards all cell lines and were chosen for further studies, such as cell cycle analysis, cell apoptosis, caspase 3/7 activity, DNA fragmentation, cell invasion, and migration. We found that these potent cytotoxic compounds induced cell cycle arrest at the S and G2/M phases, prompting apoptosis. Furthermore, these compounds significantly inhibit the invasion and migration of the different tested cancer cells. The structure-activity relationship (SAR) survey highlights that the antitumor activity of the desired compounds was affected by the hydrophobic or hydrophilic nature of the substituent at different positions.

Pyrano[3,2-c]quinoline Derivatives as New Class of α-glucosidase Inhibitors to Treat Type 2 Diabetes: Synthesis, in vitro Biological Evaluation and Kinetic Study

BACKGROUND

Pyrano[3,2-c]quinoline derivatives 6a-n were synthesized via simple two-step reactions and evaluated for their in vitro α-glucosidase inhibitory activity.

METHODS

Pyrano[3,2-c]quinoline derivatives 6a-n derivatives were prepared from a two-step reaction: cycloaddition reaction between 1-naphthyl amine 1 and malonic acid 2 to obtain benzo[h]quinoline-2(1H)-one 3 and reaction of 3 with aryl aldehydes 4 and Meldrum's acid 5. The anti- α-glucosidase activity and kinetic study of the synthesized compounds were evaluated using α-glucosidase from Saccharomyces cerevisiae and p-nitrophenyl-a-D-glucopyranoside as substrate. The α-glucosidase inhibitory activity of acarbose was evaluated as positive control.

RESULTS

All of the synthesized compounds, except compounds 6i and 6n, showed more inhibitory activity than the standard drug acarbose and were also found to be non-cytotoxic. Among the synthesized compounds, 1-(2-bromophenyl)-1H-benzo[h]pyrano[3,2-c]quinoline-3,12(2H,11H)-dione 6e displayed the highest α-glucosidase inhibitory activity (IC50 = 63.7 ± 0.5 µM). Kinetic study of enzyme inhibition indicated that the most potent compound, 6e, is a non-competitive inhibitor of α-glucosidase with a Ki value of 72 µM. Additionally, based on the Lipinski rule of 5, the synthesized compounds were found to be potential orally active drugs.

CONCLUSION

Our results suggest that the synthesized compounds are promising candidates for treating type 2 diabetes.

Introducing novel potent anticancer agents of 1H-benzo[f]chromene scaffolds, targeting c-Src kinase enzyme with MDA-MB-231 cell line anti-invasion effect

In our effort to develop novel and powerful agents with anti-proliferative activity, two new series of 1H-benzo[f]chromene derivatives, 4a–h and 6a–h, were synthesised using heterocyclocondensation methodologies under microwave irradiation condition. The structures of the target compounds were established on the basis of their spectral data, IR, ¹H NMR, ¹³ C NMR, ¹³ C NMR-DEPT/APT, and MS data. The new compounds have been examined for their anti-proliferative activity against three cancer cell lines, MCF-7, HCT-116, and HepG-2. Vinblastine and Doxorubicin have been used as positive controls in the viability assay. The obtained results confirmed that most of the tested molecules revealed strong and selective cytotoxic activity against the three cancer cell lines. Moreover, these molecules exhibited weak cytotoxicity on the HFL-1 line, which suggested that they might be ideal anticancer candidates. The SAR study of the new benzochromene compounds verified that the substituents on the phenyl ring of 1H-benzo[f]chromene nucleus, accompanied with the presence of bromine atom or methoxy group at the 8-position, increases the ability of these molecules against the different cell lines. Due to their high anti-proliferative activity, compounds 4c and 6e were selected to be examined their proficiency to inhibit the invasiveness of the highly sensitive and invasive breast cancer cell line, MDA-MB-231. The anti-invasion behaviour of these molecules against the highly sensitive, non-oestrogen, and progesterone MDA-MB-231 cell line gave rise to their decreasing metastatic effect compared to the reference drug. Furthermore, this report explores the apoptotic mechanistic pathway of the cytotoxicity of the target compounds and reveals that most of these compounds enhance the Caspase 3/7 activity that could be considered as potential anticancer agents.

Design, synthesis andin vitroα-glucosidase inhibition of novel coumarin-pyridines as potent antidiabetic agents

Herein, novel coumarin-pyridine derivatives4a–pas potent α-glucosidase inhibitors were synthesized by a one-pot and three-component synthesis method.

Crystal structure of 3-amino-1-(4-bromophenyl)-9-methoxy-1H-benzo[f]chromene-2-carbonitrile, C21H15BrN2O2

C21H15BrN2O2, triclinic, P1̅ (no. 2), a = 8.6873(3) Å, b = 9.9252(3) Å, c = 11.0013(3) Å, α = 77.977(2)°, β = 70.989(2)°, γ = 89.321(2)°, V = 875.55(5) Å3, Z = 2, Rgt(F) = 0.0369, wRref(F2) = 0.1043, T = 296(2) K.

Crystal structure of 3-amino-8-methoxy-1-(4-methoxy phenyl)-1H-benzo[f]chromene-2-carbonitrile, C22H18N2O3

C22H18N2O3, monoclinic, C2/c (no. 15), a = 35.4037(10) Å, b = 6.0294(2) Å, c = 20.1702(7) Å, β = 122.239(4)°, V = 3641.8(2) Å3, Z = 8, R gt(F) = 0.0482, wR ref(F 2) = 0.1406, T = 296(2) K.

Design of New Benzo[h]chromene Derivatives: Antitumor Activities and Structure-Activity Relationships of the 2,3-Positions and Fused Rings at the 2,3-Positions

A series of novel 4H-benzo[h]chromenes 4, 6-11, 13, 14; 7H-benzo[h]chromeno[2,3-d]pyrimidines 15-18, 20, and 14H-benzo[h]chromeno[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine derivatives 19a-e, 24 was prepared. The structures of the synthesized compounds were characterized on the basis of their spectral data. Some of the target compounds were examined for their antiproliferative activity against three cell lines; breast carcinoma (MCF-7), human colon carcinoma (HCT-116) and hepatocellular carcinoma (HepG-2). The cytotoxic behavior has been tested using MTT assay and the inhibitory activity was referenced to three standard anticancer drugs: vinblastine, colchicine and doxorubicin. The bioassays demonstrated that some of the new compounds exerted remarkable inhibitory effects as compared to the standard drugs on the growth of the three tested human tumor cell lines. The structure-activity relationships (SAR) study highlights that the antitumor activity of the target compounds was significantly affected by the lipophilicity of the substituent at 2- or 3- and fused rings at the 2,3-positions.

Structural Characterization and Antimicrobial Activities of 7H-Benzo[h]chromeno[2,3-d]pyrimidine and 14H-Benzo[h]chromeno[3,2-e][1,2,4]triazolo[1,5-c] pyrimidine Derivatives

Three new series of chromene molecules have been synthesized in order to explore their antimicrobial activity. The series encompass 2-substituted 14-(4-halophenyl)-12-methoxy-14H-benzo[h]chromeno[3,2-e][1,2,4]-triazolo[1,5-c]pyrimidines 7a-o, 9-benzylideneamino-7-(4-halo-phenyl)-5-methoxy-8-imino-7H-benzo-[h]chromeno[2,3-d]pyrimidines 8a-b and 3-ethoxycarbonyl-14-(4-halophenyl)-12-methoxy-14H-benzo-[h]chromeno[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine-2-one derivatives 12a-b. The structure of these novel compounds were confirmed using IR, ¹H- and ¹³C-NMR as well as MS spectroscopy. The new compounds were evaluated in vitro for their antimicrobial activity and it was demonstrated that 7H-benzochromenopyrimidine and derivatives of 14H-benzochromenotriazolopyrimidine exhibited the most promising antibacterial activities compared to the reference antimicrobial agents. The structure activity relationship (SAR) studies of the target compounds agreed with the in vitro essays and confirmed higher potent antimicrobial activity against some of the tested microorganisms.

Hybrids of coumarin–indole: design, synthesis and biological evaluation in Triton WR-1339 and high-fat diet induced hyperlipidemic rat models

Lipid lowering activity of novel coumarin–indole hybrids has been demonstrated.

Design and synthesis of new series of coumarin-aminopyran derivatives possessing potential anti-depressant-like activity

A new series of coumarin based aminopyran derivatives were designed, synthesized and evaluated for their preclinical antidepressant effect on Swiss albino mice. Among the series, compounds 21, 25, 26, 27, 32 and 33 exhibited significant activity profile in forced swimming test (FST). Compound 27 was most efficacious, which at a very low dose of 0.5mg/kg reduced the time of immobility by 86.5% as compared to the standard drug fluoxetine (FXT) which reduced the immobility time by 69.8% at the dose of 20mg/kg, ip. In addition, all active compounds were screened in dose dependent manner (at doses of 0.25, 0.5, 1mg/kg ip) in FST and tail suspension test (TST). Interestingly, all active compounds did not caused any significant alteration of locomotor activity in mice as compared to control, indicating that the hybrids did not produce any motor impairment effects. The results indicate that coumarin-aminopyran derivatives may have potential therapeutic value for the management of mental depression.

Synthesis and evaluation of new 3-phenylcoumarin derivatives as potential antidepressant agents

A series of amine substituted 3-phenyl coumarin derivatives were designed and synthesized as potential antidepressant agents. In preliminary screening, all compounds were evaluated in forced swimming test (FST), a model to screen antidepressant activity in rodents. Among the series, compounds 5c and 6a potentially decreased the immobility time by 73.4% and 79.7% at a low dose of 0.5 mg/kg as compared to standard drug fluoxetine (FXT) which reduced the immobility time by 74% at a dose of 20 mg/kg, ip. Additionally, these active compounds also exhibited significant efficacy in tail suspension test (TST) (another model to screen antidepressant compounds). Interestingly, rotarod and locomotor activity tests confirmed that these two compounds do not have any motor impairment effect and neurotoxicity in mice. Our studies demonstrate that the new 3-phenylcoumarin derivatives may serve as a promising antidepressant lead and hence pave the way for further investigation around this chemical space.

Discovery of coumarin-dihydropyridine hybrids as bone anabolic agents

The concept of molecular hybridization led us to discover a novel series of coumarin-dihydropyridine hybrids that have potent osteoblastic bone formation in vitro and that prevent ovariectomy-induced bone loss in vivo. In this context, among all the compounds screened for alkaline phosphatase activity, four compounds 10, 14, 18, and 22 showed significant activity at picomolar concentrations. A series of other in vitro data strongly suggested compound 18 as the most promising bone anabolic agent, which was further evaluated for in vivo studies. From these studies compound 18 proved to be useful, which at low oral dose of 1 (mg/kg)/day body weight increased bone mass density and volume, expression of osteogenic genes (RUNX2, BMP-2, and ColI), bone formation rate (BFR), and mineral apposition rate (MAR), improved the trabecular microarchitecture, and decreased bone turn over markers in an ovariectomized rodent model for postmenopausal osteoporosis.

In vitro and in vivo antifilarial activity evaluation of 3,6-epoxy [1,5]dioxocines: a new class of antifilarial agents

A series of 3,6-epoxy [1,5]dioxocines were synthesized and evaluated for their antifilarial activity against adult parasites of human lymphatic filarial parasite Brugia malayi (sub-periodic strain) in vitro. Out of these, six compounds (4a-f) possessed improved in vitro anti-filarial activity and examples 4d and 4f were also found to be active in the in vivo experiments. These results demonstrate that 3,6-epoxy [1,5]dioxocines exhibits potent antifilarial activity and might be developed into a new class of antifilarial drug.