Synthesis, biological evaluation, and molecular docking studies of new pyrazol-3-one derivatives with aromatase inhibition activities.

A new series derived from 4-(2-chloroacetyl)-1,2-dihydro-1,5-dimethyl-2-phenyl-3H-pyrazol-3-one was synthesized, characterized and its pharmacological activity toward aromatase enzyme inhibition was screened and compared to the reference native ligand letrozole. The most active compound of the series was 16, showing IC50 value of 0.0023 ± 0.0002 µm compared to letrozole with IC50 of 0.0028 ± 0.0006 µm. In addition, compounds 26 and 36 exhibit good inhibition activities close to letrozole with IC50 values 0.0033 ± 0.0001 and 0.0032 ± 0.0003 µm, respectively. Moreover, molecular docking studies were conducted to support the findings.

Novel Benzo[d]imidazole-based Heterocycles as Broad Spectrum Anti-viral Agents: Design, Synthesis and Exploration of Molecular Basis of Action.

The design and synthesis of a novel series of benzo[d]imidazole-based heterocycles and their biological evaluation as antiviral agents are reported herein. 1-(1-Methyl-1H-benzo[d]imidazol- 2-yl)-2-thiocyanatoethanone 2 was used as a key intermediate for the synthesis of the thiazolylhydrazine 4, the thiazolylamine 5 and the methylthiazole 7. Coupling of compounds 5 or 7 with the appropriate diazotized aromatic amines gave the diazenyl derivatives 6a-c and 8a-c, respectively. The quinazoline derivative 12 was also synthesized. On the other hand, the phenylthio 20 and the phenylsulphonyl 22 bioisosteresand their respective diazenyl derivatives 21a-c and 23a-c were prepared. The synthesized compounds were evaluated for their HIV-1, HCV, SSPE and H1N1 inhibitory activities and were found to display very promising results. Furthermore, to investigate the underlying possible mechanism of action, in vitro and in silico screening of this series of benzo[d]imidazoles was performed against the viral enzymes HIV-1 RT, HCV NS3/4A serine protease and H1N1 NA1. Overall findings of the executed investigations highlight these novel compounds as very promising potent, broad spectrum antiviral agents.

New Coumarin Derivatives as Potent Selective COX-2 Inhibitors: Synthesis, Anti-Inflammatory, QSAR, and Molecular Modeling Studies.

Two new series of coumarin derivatives incorporating thiazoline and thiazolidinone moieties were designed, synthesized, and investigated in vivo for their anti-inflammatory activities using the carrageenan-induced rat paw edema model and in vitro for their inhibitory activities against the human cyclooxygenase (COX)-1 and COX-2 isoforms. Most of the synthesized compounds demonstrated exceptionally high in vivo anti-inflammatory activity and displayed superior GI safety profiles (0-7% ulceration) as compared to indomethacin. All the bioactive compounds showed in vitro high affinity and selectivity toward the COX-2 isoenzyme, compared to the reference celecoxib with IC50 values ranging from 0.31 to 0.78 µM. The ethyl thiosemicarbazone 2b, thiazoline derivatives 3a, 3b, 5b, 6a, and 7f, and the thiazolidinone compounds 8b and 9a showed the highest in vivo and in vitro anti-inflammatory activities with remarkable COX-2 selectivity. Quantitative structure-activity relationship study (QSAR) was done and resulted in a highly predictive power R(2) (0.908). A molecular docking study revealed a relationship between the docking affinity and the biological results.

Novel 4-heteroaryl-antipyrines as DPP-IV inhibitors.

Type 2 diabetes mellitus is a vast growing progressive disease that almost affects one person among every twelve globally. Regardless the availability of wide variety of oral hypoglycemics, only one-third of patients achieves proper glycemic control. With the advantage of the low risk of hypoglycemia, DPP-IV attracted the attention of medicinal chemists as a new target for oral hypoglycemics. In this report, a lead compound 1, with antipyrine scaffold, was obtained, and its binding mode was calculated. Several derivatives with bridged nitrogenous heterocycles have been synthesized via multicomponent reaction under controlled microwave heating conditions. The antidiabetic activity versus DPP-IV protein was evaluated and compared with sitagliptin. Compounds with smaller- or medium-sized nitrogenous bridges were comparable with sitagliptin in terms of DPP-IV inhibitory activity, potentially via targeting Glu203 and Glu204. The oral hypoglycemic activities of compounds with submicromolar IC50 values were further evaluated using diabetic mouse model.

Anti-inflammatory activities of some newly synthesized pyridinyl- and indazolyl benzamide derivatives.

A series of substituted (pyridin-4-yl)phenyl-2-methoxybenzamide and their derivatives were prepared and screened for their anti-inflammatory activities. Initially the acute toxicity of the compounds was assayed via the determination of their LD50. Some of the newly synthesized compounds exhibited better pharmacological and biological responses than the reference controls with low concentrations. The structures of newly synthesized compounds were confirmed by chemical, elemental and spectroscopic evidences.

Design and synthesis of potent 1,2,4-trisubstituted imidazolinone derivatives with dual p38αMAPK and ERK1/2 inhibitory activity.

The synthesis of new 1,2,4-trisubstituted imidazolinone derivatives was described. The new compounds were designed as dual p38αMAPK and ERK1/2 inhibitors through hybridization of pharmacophoric elements associated with inhibition of these kinases. The kinase inhibition assay revealed excellent activity in the nanomolar range; especially compounds 6d and 7h which seemed promising candidates for such dual activity with IC50 values of 4.5 and 4.7 nM against p38αMAP, 25.0 and 24.0 nM against ERK1, and 3.2 and 3.5 nM against ERK2, respectively. These compounds were further tested for their antiproliferative activity against nine cancer cell lines, where they elicited high activity in the sub-micromolar range against breast, prostate and melanoma cells.

Identification of novel aminothiazole and aminothiadiazole conjugated cyanopyridines as selective CHK1 inhibitors.

Inhibitors of checkpoint kinase 1 (CHK1) are of current interest as potential anti-tumor agents. Novel series of cyanopyridyl-aminothiadiazoles (synthesized from reaction of 1-(3-cyano-4,6-diphenylpyridin-2-yl)-3-phenylthiourea (14) with hydrazonoyl halides) and cyanopyridyl-aminothiazolyl-thiadiazoles (synthesized from treatment of 14 with ethyl chloroacetate followed by reaction of the obtained cyanopyridyl-aminothiazole with hydrazonoyl halides) were synthesized and evaluated for their CHK1 inhibitory potential using a cell-based assay cascade. The tested compounds exhibited a potent and selective CHK1 inhibitory activity at nanomolar levels that reflected their ability to abrogate cell cycle arrest and potentiate the cytotoxic effect of the genotoxic drug gemcitabine in colon cancer cells. Molecular modeling simulation revealed that, the most active compound 28a docked well into the enzyme active site and their complex is stabilized by a key H-bonding with the backbone amide of Cys-87 as well as multiple favorable hydrophobic interactions with different hydrophobic binding regions of the enzyme.

Synthesis and anticancer activity of some 8-substituted-7-methoxy-2H-chromen-2-one derivatives toward hepatocellular carcinoma HepG2 cells.

Based on the reported anticancer activity of coumarin and pyrazoline derivatives, the present investigation dealt with the design and synthesis of coumarin derivatives bearing diversely substituted pyrazoline moieties 7-10. The non-cyclic isosteres 11a-e of compounds 10a-e were synthesized for comparative reasons. The target compounds were synthesized from 8-acetyl-7-methoxycoumarin that underwent Claisen-Schmidt condensation with various aldehydes to give the chalcones 6a-e, followed by reaction with hydrazine hydrate, phenyl hydrazine or semicarbazide under the appropriate conditions. Cytotoxicity of the synthesized compounds was evaluated in vitro against liver HepG2 cell line. Compounds were active in the nanomolar range. The most active compounds were investigated for their telomerase inhibition and proapoptotic activities.

Diphenylpyrroles: Novel p53 activators.

Cellular tumor antigen p53 is crucial for cancer prevention via different mechanisms. E3 ubiquitin-protein ligase HDM2 binds to p53, blocks its ability to activate transcription, and therefore acts as a negative regulator. Blocking p53 binding site on HDM2 was believed to generate efficient antitumor agents. So far, limited scaffolds were reported with HDM2 antagonist activity. Herein, diphenylpyrroles were introduced and evaluated as a novel scaffold in the field of p53 activators. An efficient synthesis of novel 3-heteroaryl-pyrroles is described via reactions of E-3-(dimethylamino)-1-(2-methyl-4,5-diphenyl-1H-pyrrol-3-yl)prop-2-en-1-one or E-1-(2-methyl-4,5-diphenyl-1H-pyrrol-3-yl)-3-morpholinoprop-2-en-1-one with hydrazine hydrate, phenyl hydrazine, hydroxylamine, various heterocyclic amines and active methylene compounds.

Anti-arthritic and immunosuppressive activities of substituted triterpenoidal candidates.

We herein report the anti-arthritic and immunosuppressive activities of some synthesized substituted terpenoidal structure. Forty-four triterpenoid derivatives 1-21 containing a carboxylic, ester, amide and ketone groups attached to a triterpene moiety were conveniently synthesized and screened for their anti-arthritic and immunosuppressive activities. Synthetic triterpenoidal structures linked to a different function groups seem to be a promising approach in the search for novel leads for potent anti-arthritic and immunosuppressive agents. The detailed synthetic pathways of obtained compounds and anti-arthritic and immunosuppressive activities were reported.

Design, synthesis and structure-activity relationship study of novel pyrazole-based heterocycles as potential antitumor agents.

The versatile hitherto unreported 3-[(E)-3-(dimethylamino)acryloyl]-1,5-diphenyl-1H-pyrazole-4-carbonitrile (3) was prepared via the reaction of 3-acetyl-1,5-diphenyl-1H-pyrazole-4-carbonitrile (1) with dimethylformamid-dimethylacetal (DMF-DMA). The latter product and 3-((E)-3-morpholin-4-yl-acryloyl)-1,5-diphenyl-1H-pyrazole-4-carbonitrile (4) underwent regioselective 1,3-dipolar cycloaddition with nitrilimines to afford the corresponding pyrazole derivatives. In vivo anti-estrogenic activity and acute toxicity after single oral dose of the newly synthesized compounds were evaluated. In vitro disease-oriented primary antitumor screening utilizing 14 cell lines of breast and ovarian tumor subpanels has been also carried out. All tested compounds showed anti-estrogenic properties equipotent or superior to the reference drug, letrozole. 3-[3-(4-Cyano-1,5-diphenyl-1H-pyrazole-3-yl)-1-(4-methylphenyl)-1H-pyrazole-4-carbonyl]-1,5-diphenyl-1H-pyrazole-4-carbonitrile (27c) and 3-(3-acetyl-1-phenyl-1H-pyrazole-4-carbonyl)-1,5-diphenyl-1H-pyrazole-4-carbonitrile (8a) showed a significant cytotoxic activity in a nanomolar range against certain types of breast and ovarian tumors with tolerable toxicity.

Synthesis and structure-activity relationship studies of pyrazole-based heterocycles as antitumor agents.

Several 4-cyano-1,5-diphenylpyrazoles attached to different heterocyclic ring systems at position 3 were synthesized starting from ethyl 4-cyano-1,5-diphenyl-1H-pyrazole-3-carboxylate 1. The newly synthesized compounds were tested in vivo for their anti-estrogenic effects and evaluated in vitro for their cytotoxic properties against estrogen-dependent tumors. 3-(5-Mercapto-1,3,4-oxadiazole-2-yl)-1,5-diphenyl-1H-pyrazole-4-carbonitrile 13 revealed the highest cytotoxic activity with a GI(50) value equal to 40 nM against the IGROVI ovarian tumor cell line. It also showed an anti-estrogen activity 1.6 more effective than the reference drug, in addition to a high tolerable dose. 3-(5-(Methylthio)-4-phenyl-4H-1,2,4-triazol-3-yl)-1,5-diphenyl-1H-pyrazole-4-carbonitrile 7 was found to have the highest anti-estrogenic activity, while 1,5-diphenyl-3-[5-(phenylamino)-1,3,4-thiadiazol-2-yl]-1H-pyrazole-4-carbonitrile 11 showed the lowest activity. The oral LD(50) values revealed that most of the tested compounds are relatively nontoxic.

Anti-inflammatory and analgesic activities of some newly synthesized pyridinedicarbonitrile and benzopyranopyridine derivatives.

In continuation of our search for new substituted pyridine based anti-inflammatories, reaction of 1-(2-thienyl or furanyl)-3-(2-hydroxyphenyl)-2-propen-1-ones (1) with malononitrile in alcoholic KOH solution afforded a mixture of 4-alkoxy-2-(2-thienyl or furanyl)-5H-[1]benzopyrano[3,4-c]pyridine-5-ones (2) and 2-alkoxy-4-amino-6- (2-thienyl or furanyl)-3,5-pyridinedicarbonitriles (3). Some of the synthesized compounds were evaluated for their anti-inflammatory and analgesic activities compared to diclofenac potassium as positive control. Detailed synthesis, spectroscopic and toxicity data are reported.

New steroidal derivatives synthesized using 3beta-hydroxyandrosten-17-one as starting material.

In this study, we synthesized some new substituted steroidal derivatives using 3beta-hydroxyandrosten-17-one (dehydroepiandrosterone) as starting material. The synthesized steroidal derivatives 1-11 were evaluated for their androgenic-anabolic activities compared to testosterone as positive control. Details of the synthesis, spectroscopic data and toxicity (LD50) of synthesized compounds are reported.

Anti-inflammatory profile of some synthesized heterocyclic pyridone and pyridine derivatives fused with steroidal structure.

We herein report the anti-inflammatory activity of some newly synthesized heterocyclic pyridone and pyridine derivatives fused with steroidal structure. Initially the acute toxicity of the compounds was assayed via the determination of their LD(50). All compounds, except 3b, 22, and 23, were interestingly less toxic than the reference drug (Prednisolone). Regarding the protection against Carrageenan-induced edema, eight compounds were found to be more potent than Prednisolone. On the other hand, in searching for COX-2 inhibitor, the inhibition of plasma PGE2 for the compounds was determined and four compounds were found to be more potent than the reference drug. The structure assignment of the new compounds was based on chemical and spectroscopic evidence.

Synthesis and anti-inflammatory activities of new cyanopyrane derivatives fused with steroidal nuclei.

Thirteen new heterocyclic derivatives containing a cyanopyrane ring fused to a steroidal moiety were conveniently synthesized and screened for their anti-inflammatory potencies comparable to that of the glucocorticoid prednisolone. Four compounds 5a, 5b, 6b, and 8 exhibited superior anti-inflammatory indices (in rats, protection against carrageenan induced edema and inhibition of plasma PGE). All the candidates were less toxic than the reference drug concerning LD(50) values. Synthetic steroidal structures fused to a substituted cyanopyrane ring seem to be a promising approach in search for novel leads for potent anti-inflammatory agents.

4-Chloro-2,2-disubstituted chromen-3-carboxaldehyde: synthesis of some fused polycyclic heterocycles as anti-inflammatory, analgesic, anticonvulsant, and antiparkinsonian agents.

Some new aldazino 4, pyrazolo 5, thieno 8, and thiooxopyrimidino chromenes 10 were prepared via reaction of the corresponding beta-chlorocarboxaldehyde 3 with hydrazine hydrate, mercaptoacetic acid, and thiourea, respectively. Wherever, 4-chlorochromene derivatives 2 along with 4-chlorochromen-3-carboxaldehyde derivatives 3 were prepared from the corresponding ketone 1 with Vilsmeier-Haack reagent. Some of the new products showed good anti-inflammatory, analgesic, anticonvulsant, and antiparkinsonian activities comparable to indomethacin, diclofenace, carbamazepine, and benztropine.

Synthesis and reactions of some new substituted pyridine and pyrimidine derivatives as analgesic, anticonvulsant and antiparkinsonian agents.

A series of substituted pyridine and pyrimidine derivatives were synthesized as analgesic, anti convulsant, and antiparkinsonian agents by using compounds 1, 2, and 9 as starting materials. Pyr idino-imide derivative 3 was prepared by condensation of 1 with tetrachlorophthalic anhydride and compounds 4 and 5 were also obtained by reaction of compound 1 with 1,2,4,5-benzene-tetra carboxylic dianhydride and 1,4,5,8-naphthalenetetracarboxylic dianhydride, respectively. Similarly, compound 2 was reacted with previous anhydrides to afford the corresponding imide 6 and bis-imide derivatives 7 and 8, respectively. Bis-arylmethylene derivatives 9 were treated with hydrogen peroxide to afford the corresponding bis-oxiranocycloalkanone derivatives 10, which condensed with thiourea to give the corresponding thioxopyrimidine derivatives 11. Treatment of compound 11 with chloroacetic acid in the presence of anhydrous sodium acetate afforded the corresponding thiazolopyrim idine derivative 12 which condensed with aromatic aldehydes in acetic acid/acetic anhydride to give arylmethylene derivative 13. Also, compounds 13 could be prepared by reaction of compounds 11 with chloroacetic acid, aromatic aldehydes, and sodium acetate in a mixture of acetic acid and acetic anhydride. The pharmacological screening showed that many of these obtained compounds have good analgesic, anticonvulsant, and antiparkinsonian activities comparable to Valdecoxib, Carbamazepine, and Benzatropine as reference drugs.