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The P2Y 14 nucleotide receptor, a subtype of P2Y receptors, is implicated in many human inflammatory diseases. Based on the identification of favorable residues of two screening hits in the almost symmetrical P2Y 14 binding domain, we describe the structural optimization of previously identified virtual screening hits 6 and 7 that result in the development of P2Y 14 R antagonists with a novel 2-phenyl-benzoxazole acetamide chemical scaffold. Notably, compound 52 showed potent P2Y 14 R antagonistic activity (IC 50  = 2 nM), and a stronger inhibitory effect on MSU-induced inflammatory in vitro, better than a previously described P2Y 14 R antagonist PPTN. In vivo evaluation demonstrated that compound 52 also had satisfactory inhibitory activity on the inflammatory response of gout flares in mice. Moreover, P2Y 14 R antagonist 52 decreased paw swelling and inflammatory cell infiltration through cAMP/NLRP3/GSDMD signaling pathways in MSU-induced acute gouty arthritis mice. The discussions on the binding mechanism that employ MM/GBSA free energy calculations/decompositions also provide some useful clues for further structural designing of compound 52. Taken together, 2-phenyl-benzoxazole acetamide derivative 52 with potent P2Y 14 R antagonistic activity and in vivo potency could be a promising strategy for gout therapy and deserves further optimization., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Hepatocellular carcinoma (HCC) is a major contributor to global cancer incidence and mortality. Many pathways are involved in the development of HCC and various proteins including mTOR and HDACs have been identified as potential drug targets for HCC treatment. In the present study, two series of novel hybrid molecules targeting mTOR and HDACs were designed and synthesized based on parent inhibitors (MLN0128 and PP121 for mTOR, SAHA for HDACs) by using a fusion-type molecular hybridization strategy. In vitro antiproliferative assays demonstrated that these novel hybrids with suitable linker lengths exhibited broad cytotoxicity against various cancer cell lines, with significant activity against HepG2 cells. Notably, DI06, an MLN0128-based hybrid, exhibited antiproliferative activity against HepG2 cells with an IC 50 value of 1.61 μM, which was comparable to those of both parent drugs (MLN0128, IC 50  = 2.13 μM and SAHA, IC 50  = 2.26 μM). In vitro enzyme inhibition assays indicated that DI06, DI07 and DI17 (PP121-based hybrid) exhibited nanomolar inhibitory activity against mTOR kinase and HDACs (e.g., HDAC1, HDAC2, HDAC3, HADC6 and HADC8). Cellular studies and western blot analyses uncovered that in HepG2 cells, DI06 and DI17 induced cell apoptosis by targeting mTOR and HDACs, blocked the cell cycle at the G0/G1 phase and suppressed cell migration. The potential binding modes of the hybrids (DI06 and DI17) with mTOR and HDACs were investigated by molecular docking. DI06 displayed better stability in rat liver microsomes than DI07 and DI17. Collectively, DI06 as a novel mTOR and HDACs inhibitor presented here warrants further investigation as a potential treatment of HCC., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Diabetic nephropathy (DN) is resulted from activations of polyol pathway and oxidative stress by abnormal metabolism of glucose, and no specific medication is available. We designed a novel class of benzoxazolone derivatives, and a number of individuals were found to have significant antioxidant activity and inhibition of aldose reductase of the key enzyme in the polyol pathway. The outstanding compound (E)-2-(7-(4-hydroxy-3-methoxystyryl)-2-oxobenzo[d]oxazol-3(2H)-yl)acetic acid was identified to reduce urinary proteins in diabetic mice suggesting an alleviation in the diabetic nephropathy, and this was confirmed by kidney hematoxylin-eosin staining. Further investigations showed blood glucose normalization, declined in the polyol pathway and lipid peroxides, and raised glutathione and superoxide dismutase activity. Thus, we suggest a therapeutic function of the compound for DN which could be attributed to the combination of hypoglycemic, aldose reductase inhibition and antioxidant., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

In this study, four series of compounds with benzoxazolone and benzothiazolone cores were designed, synthesized and evaluated as multifunctional agents against Alzheimer's disease (AD). Additionally, in order to shed light on the effect of the carbonyl groups of benzoxazolone/benzothiazolone, benzoxazole/benzothiazole-containing analogues were also synthesized and evaluated. Inhibition potency of all final compounds towards cholinesterase enzymes and their antioxidant activity were tested. Subsequently, the anti-inflammatory activity, cytotoxicity, apoptosis, and Aβ aggregation inhibition tests were also performed for selected compounds. The results indicated that compounds 11c, a pentanamide derivative with benzothiazolone core, and 14b, a keton derivative with benzothiazolone core, were considered as promising multi-functional agents for further investigation against AD. The reversibility, kinetic and molecular docking studies were also performed for the compounds with the highest AChE 14b (eeAChE IC 50  = 0.34 μM, huAChE IC 50  = 0.46 μM) and BChE 11c (eqBChE IC 50  = 2.98 μM, huBChE IC 50  = 2.56 μM) inhibitory activities., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The authors declare no conflict of interest., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Phortress is an anticancer prodrug, which has active metabolite (5F-203) being potent agonist of the aryl hydrocarbon receptor (AhR). The 5F-203 switches on cytochrome P450 CYP1A1 gene expression and thus exhibits anticancer activity. In this study, it is aimed to obtain new phortress analogues by bioisosteric replacement of benzothiazole core in the structure to benzoxazole ring system. Synthesis of compounds (3a-3p) were performed according to literature methods. Their structures were elucidated by IR, 1 H NMR, 13 C NMR, 2D-NMR and HRMS spectroscopic methods. Cytotoxicity (MTT), inhibition of DNA synthesis and flow cytometric analysis assays were applied to determine anticancer activity of the compounds on colon (HT-29), breast (MCF7), lung (A549), liver (HepG2) and brain (C6) carcinoma cell types. When compared reference agent doxorubicin, compounds 3m and 3n displayed very attractive anticancer effect against carcinogenic cell lines. Due to structural similarity to phortress, biotransformation studies for 3m and 3n were examined by LCMS-IT-TOF system and probable metabolites of these compounds were determined. Induction potential of these compounds on CYP1A1/2 enzymes was also investigated to clarify possible mechanism of action. Interaction modes between CYP1A1 enzyme and compound 3n or its some metabolites were investigated by docking studies. In conclusion, findings of these study indicate that compounds 3m and 3n possess significant anticancer activity, probably with the same mechanism of action to Phortress., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Patients suffering from dementia experience cognitive deficits and 90% of them show non-cognitive behavioral and psychological symptoms of dementia (BPSD). The spectrum of BPSD includes agitation, depression, anxiety and psychosis. Antipsychotics, e.g. quetiapine, have been commonly used off-label to control the burdensome symptoms, though they cause serious side effects and further cognitive impairment. Therefore, the development of targeted therapy for BPSD, suitable for elderly patients, remains relevant. A multitarget-directed ligand, acting on serotonin 5-HT 2A and dopamine D 2 receptors (R) and thus exerting anti-aggressive and antipsychotic activity, as well as on 5-HT 6 Rs and 5-HT 7 Rs (potential pro-cognitive, antidepressant and anxiolytic activity), poses a promising strategy for the treatment of BPSD. Antitargeting muscarinic M 3 R and hERG channel is expected to reduce the risk of side effects. We obtained a series of stereoisomeric compounds by combining 6-fluoro-1,2-benzoxazole moiety and arylsulfonamide fragment through pyrrolidin-1-yl-propyl linker. N-[(3R)-1-[3-(6-fluoro-1,2-benzoxazol-3-yl)propyl]pyrrolidin-3-yl]-1-benzothiophene-2-sulfonamide showed a substantial affinity for the targets of interest (pK i  = 8.32-9.35) and no significant interaction with the antitargets. Functional studies revealed its antagonist efficacy (pK B  = 7.41-9.03). The lead compound showed a promising profile of antipsychotic-like activity in amphetamine- and MK-801-induced hyperlocomotion (MED = 2.5 mg/kg), antidepressant-like, as well as anxiolytic-like activity in mice (MED = 0.312 and 1.25 mg/kg in the forced swim and four-plate tests, respectively). Notably, the novel compound didn't affect spontaneous locomotor activity, nor induced catalepsy or memory deficits (step-through passive avoidance test) in therapeutically relevant doses, which proved its benign safety profile. The overall pharmacological characteristics of the lead compound outperformed the reference drug quetiapine, making it a promising option for evaluation in the treatment of BPSD., Competing Interests: Declaration of competing interest The authors declare the following competing financial interest(s): AB, MM and JS have received honoraria from and MK is an employee of Adamed Pharma S.A. The other authors report no conflict of interest and have nothing to disclose., (Copyright © 2020 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Chemical probes of epigenetic 'readers' of histone post-translational modifications (PTMs) have become powerful tools for mechanistic and functional studies of their target proteins in physiology and pathology. However, only limited 'reader' probes have been developed, which restricted our understanding towards these macromolecules and their roles in cells or animals. Here, we reported a structure-guided approach to develop and characterize benzo [d]oxazol-2(3H)-one analogs as the first potent and selective small-molecule inhibitors of chromodomain Y-like (CDYL), a histone methyllysine reader protein. The binding conformation between the chromodomain of CDYL and the modified peptidomimetics was studied via molecular docking and dynamic simulations, facilitating subsequent virtual screening of tens of hits from Specs chemical library validated by SPR technique (K D values: from 271.1 μM to 5.4 μM). Further design and synthesis of 43 compounds helped to interpret the structure-activity relationship (SAR) that lead to the discovery of novel small-molecule inhibitors of CDYL. Compound D03 (K D : 0.5 μM) was discovered and showed excellent selectivity among other chromodomain proteins, including CDYL2 (>140 folds), CDY1 (no observed binding) and CBX7 (>32 folds). Moreover, we demonstrated that D03 engaged with endogenous CDYL in a dose-dependent manner, and perturbed the recruitment of CDYL onto chromatin, resulting in transcriptional derepression of its target genes. Finally, the results showed that D03 promoted the development and branching of neurodendrites by inhibiting CDYL in hippocampal and cortical cultured neurons. This study not only discovers the first selective small-molecule inhibitors of CDYL, but provids a new chemical tool to intervene the dynamic nature of bio-macromolecules involved in epigenetic mechanism., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Herein, we have carried out a structural optimization campaign to discover the novel anti-tumor agents with our previously screened YQY-26 as the hit compound. A library of thirty-seven 6-amide-2-aryl benzoxazole/benzimidazole derivatives has been designed and synthesized based on the highly conserved active site of VEGFR-2. Several title compounds exhibited selective inhibitory activities against VEGFR-2 than EGFR kinases, which also displayed selective anti-proliferation potency against the HUVEC and HepG2 than the A549 and MDA-MB-231 cancer cell lines. The newly synthesized compounds were evaluated for anti-angiogenesis capability by chick chorioallantoic membrane (CAM) assay. Among them, compounds 9d showed the most potent anti-angiogenesis ability (79% inhibition at 10 nM/eggs), the efficient cytotoxic activities (in vitro against the HUVEC and HepG2 cell lines with IC 50 values of 1.47 and 2.57 μM, respectively), and excellent VEGFR-2 kinase inhibition (IC 50  = 0.051 μM). The molecular docking analysis revealed that compound 9d is a Type II inhibitor of VEGFR-2 kinase. These results indicated that the 6-amide-2-arylbenzoxazole and 6-amide-2-aryl benzimidazole derivatives are promising inhibitors of VEGFR-2 kinase for the potential treatment of anti-angiogenesis., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

A new set of 5-chlorobenzoxazole- and 5-chlorobenzothiazole-based derivatives containing the azepane ring as a basic moiety was designed, synthesized and evaluated through binding assays to measure their affinity and selectivity towards σ 1 and σ 2 receptors. Compounds 19, 22 and 24, with a four units spacer between the bicyclic scaffold and the azepane ring, showed nanomolar affinity towards both receptor subtype and the best K i values (K i σ 1  = 1.27, 2.30, and 0.78 and K i σ 2  = 7.9, 3.8, and 7.61 nM, respectively). Evaluation of cytotoxic and apoptotic effects in MCF-7 human cancer cells was useful to assess σ 2 receptor activity, while an in vivo mice model of inflammatory pain allowed to analyze σ 1 receptor pharmacological properties. In vitro and in vivo results suggested that compound 19 is a σ 1 /σ 2 agonist, compound 24 a σ 1 antagonist/σ 2 agonist, whereas compound 22 might act as σ 1 antagonist/σ 2 partial agonist. Due to their pharmacological profile, a potential therapeutic application in cancer of aforesaid novel σ 1 /σ 2 receptor ligands, especially 22 and 24, is proposed., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Based on the Gaussian-based quantitative structure-activity relationship (QSAR) and virtual screening (VS) processes, some promising acetylcholinesterase inhibitors (AChEIs) having antioxidant potential were designed synthesized, characterized, and evaluated for their ability to enhance learning and memory. The synthesized phenyl benzoxazole derivatives exhibited significant antioxidant potential and AChE inhibitory activity, whereas the antioxidant potential of compound 34 (49.6%) was observed significantly better than standard donepezil (<10%) and parallel to ascorbic acid (56.6%). Enzyme kinetics study of most potent compound 34 (AChE IC 50  = 0.363 ± 0.017 μM; Ki = 0.19 ± 0.03 μM) revealed the true nature and competitive type of inhibition on AChE. The compound 34 was further assessed for in vivo and ex vivo studies and the results showed the significant reversal of cognitive deficits and antioxidant potential at the dose of 5 mg/kg comparable to standard drug donepezil., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

The aldo-keto reductase 1C3 (AKR1C3) isoform plays a vital role in the biosynthesis of androgens and is considered an attractive target in prostate cancer (PCa). No AKR1C3-targeted agent has to date been approved for clinical use. Flufenamic acid and indomethacine are non-steroidal anti-inflammatory drugs known to inhibit AKR1C3 in a non-selective manner as COX off-target effects are also observed. Recently, we employed a scaffold hopping approach to design a new class of potent and selective AKR1C3 inhibitors based on a N-substituted hydroxylated triazole pharmacophore. Following a similar strategy, we designed a new series focused around an acidic hydroxybenzoisoxazole moiety, which was rationalised to mimic the benzoic acid role in the flufenamic scaffold. Through iterative rounds of drug design, synthesis and biological evaluation, several compounds were discovered to target AKR1C3 in a selective manner. The most promising compound of series (6) was found to be highly selective (up to 450-fold) for AKR1C3 over the 1C2 isoform with minimal COX1 and COX2 off-target effects. Other inhibitors were obtained modulating the best example of hydroxylated triazoles we previously presented. In cell-based assays, the most promising compounds of both series reduced the cell proliferation, prostate specific antigen (PSA) and testosterone production in AKR1C3-expressing 22RV1 prostate cancer cells and showed synergistic effect when assayed in combination with abiraterone and enzalutamide. Structure determination of AKR1C3 co-crystallized with one representative compound from each of the two series clearly identified both compounds in the androstenedione binding site, hence supporting the biochemical data., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

In the present study, we attempted to develop novel class of Mycobacterium tuberculosis (Mtb) inhibitors by exploring the pharmaceutically underexploited enzyme targets which are majorly involved in cell wall biosynthesis of mycobacteria. For this purpose glutamate racemase was selected which racemizes d-glutamate from l-glutamate, a key step in peptidoglycan synthesis. Furthermore, enzyme is neither expressed nor its product, d-glutamate is produced in mammals, and hence inhibiting this enzyme will have no vulnerable effect in host organism. A library of our in-house compounds were screened against glutamate racemase using a biophysical technique; thermal shift assay and further by enzyme inhibition assay to identify Lead 1 molecule. Lead 1 optimization and expansion resulted in twenty four compounds. Among the synthesized compounds twelve compounds shown good enzyme inhibition than Lead 1 (IC 50 20.07 ± 0.29 μM). Among all the compounds; compound 22 (IC 50 1.1 ± 0.52 μM) showed potent non-competitive mode of inhibition in enzyme assay. Further showed good susceptibility (in replicating bacteria) of MIC 8.72 μM and bactericidal time dependant kill on dormant culture. It also exhibited significant activity in Mtb nutrient starvation model (2.5) and Mtb biofilm model (2.4) and in vivo M. marinum infected Zebra fish model studies (3.6) reduction at logarithmic scale., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

In this report, we present a new benzoxazole derivative endowed with inhibitory activity against the HIV-1 nucleocapsid protein (NC). NC is a 55-residue basic protein with nucleic acid chaperone properties, which has emerged as a novel and potential pharmacological target against HIV-1. In the pursuit of novel NC-inhibitor chemotypes, we performed virtual screening and in vitro biological evaluation of a large library of chemical entities. We found that compounds sharing a benzoxazolinone moiety displayed putative inhibitory properties, which we further investigated by considering a series of chemical analogues. This approach provided valuable information on the structure-activity relationships of these compounds and, in the process, demonstrated that their anti-NC activity could be finely tuned by the addition of specific substituents to the initial benzoxazolinone scaffold. This study represents the starting point for the possible development of a new class of antiretroviral agents targeting the HIV-1 NC protein., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

A number of naphtho[1,2-d]oxazole derivatives were synthesized and evaluated for their anti-HCV virus activity. Among them, compound 18 was the most active, exhibited approximately 21-folds more active anti-HCV activity (IC 50 of 0.63 μM) than that of ribavirin (IC 50  = 13.16 μM). Compound 18 was less cytotoxic than ribavirin, and the selective index (SI) of 18 is approximately 28-folds higher than that of ribavirin (229.10 v.s. 8.08). By using heme oxygenase-1 (HO-1) promoter-based assay and western blotting, compound 18 could induce HO-1 promoter activity, and protein expression. The antiviral effect of compound 18 was attenuated by HO-1 specific inhibitor SnPP treatment, which indicated that compound 18 suppressed HCV replication through inducing HO-1 expression. We further found that compound 18 reduced bach1 expression resulting in increasing the activity of Nrf-2 binding element. Moreover, the induction of HO-1 by compound 18 reduced HCV NS3/4A protease activity and induced the antiviral interferon responses. Therefore, compound 18 can be considered as a supplemental antiviral agent or a lead compound for further developing more effective agents against HCV replication., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

The synthesis of (S)-2-(4-tert-butylphenoxy)-3-(benzoxazol-5-yl) propanoic acid derivatives (2a-k) were described and their in vitro antibacterial activities were determined against Gram-negative and -positive bacteria. These compounds were found to exert a broad spectrum of activity against the screened bacteria, but poor MIC values were found for Candida albicans fungi. Compound 2b bearing a hydrophobic aromatic tie was the most active derivative against all bacteria studied with MIC values ranging from 0.098 to 0.78 μg/mL. The activity of 2b against B. subtilis was 2-fold higher than Penicillin, and 8- to 510-fold higher than other control antibiotics., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

A series of novel hybrids based on benzofuroxan derivatives and fluoroquinolones (4a-d-6a-d) have been synthesized. Unexpectedly, the reactions have resulted in salt products formation during the hydrolysis of benzofuroxans by water molecules being present in the solvent instead of usual substitution products. All the compounds have been screened for antimicrobial and toxic activities. All resulting compounds retain high activity characteristic for fluoroquinolones. Many of the salts based on benzofuroxans and fluoroquinolones have higher activity than starting fluoroquinolones against Bacillus cereus 8035. Among the screened compounds, the compound 4d has shown the best antibacterial activity against B. cereus 8035, 8 times higher than the original Lomefloxacin (MBC value 1.5 μg/mL)., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

Analysis of the results of studies of docking 1 and 7a with c-Met kinase led to the identification of benzo[d]oxazol-2(3H)-one-quinolone derivatives as potential inhibitors of this enzyme. A molecular hybrid strategy, using a 4-ethoxy-7-substituted-quinoline core and a benzo[d]oxazol-2(3H)-one scaffold, was employed to design members of this family for study as inhibitors of the kinase and proliferation of EBC-1 cells. Most of the substances were found to display good to excellent c-Met kinase inhibitory activities. The results of a structure-activity relationship (SAR) study led to the discovery of benzo[d]oxazol-2(3H)-one-quinolone 13, which has IC50 values of 1 nM against c-Met kinase and 5 nM against proliferation of the EBC-1 cell line., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

A series of oxazolo[4,5-g]quinazolin-2(1H)-one derivatives employing Erlotinib as lead compound were synthesized and evaluated for their EGFR inhibition activity. These compounds having variation at the 1 and 8-position, included ether and esters hydrophilic side-chain and aromatic head fragment, respectively. All these compounds were evaluated by EGFR inhibition and two anti-proliferation assays in vitro. Four compounds were found more potent than Erlotinib in EGFR-TK assay. Furthermore, compounds 18, 42 and 50 also had good to excellent anti-proliferation activity against human epidermoid cancer cell line (KB) and renal cell carcinoma cell line (A498). Finally, compound 50 presented remarkably higher inhibition efficacy towards tumor growth than Erlotinib in a mouse lewis lung cancer (LLC) xenograft model. Furthermore, compound 50 displayed the most distinguished effect on extending the survival period of the tumor-bearing mice., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

New compounds containing both benzofuroxan and benzothiazole scaffolds were synthesized through electrophile/nucleophile combination of nitrobenzofuroxan derivatives and 2-mercapto- or 2-aminobenzothiazole derivatives and their biological effect on the natural strain Vibrio genus and different bacterial lux-biosensors was studied. Among all the compounds synthesized, that obtained from 2-mercaptobenzothiazole and 7-chloro-4,6-dinitrobenzofuroxan was toxic for bacterial cells, and also able to activated the 1st type Quorum Sensing system. The reaction between 7-chloro-4,6-dinitrobenzofuroxan and 2-aminobenzothiazole derivatives gave two products, one bearing the benzofuroxan moiety linked to the exocyclic amino nitrogen, and the second derived from the attack of two molecules of electrophile to both the nitrogen atoms of the benzothiazole reagent. Their relative ratio is modifiable by tuning the reagents ratio and the reaction time., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

The σ1 proteins are considered to be a new class of target structures for several central nervous system disorders, including depression, anxiety, psychosis, and Parkinson's and Alzheimer's diseases. Recently, the involvement of these receptors in neuropathic pain and cancer has also been observed. So far, only a few ligands are in clinical trials. In a continuation of our previous studies on the development of σ1 ligands, a new series of benzannulated heterocycles was designed and synthesised. In vitro competition binding assays showed that many of them possessed high σ1 receptor affinity (Ki = 0.6-10.3 nM), and good σ2/σ1 subtype selectivity, without cytotoxic effects on SY5Y cells (human neuroblastoma cell line)., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

Four neutral (99m)Tc/Re-labeled 2-arylbenzoxazole derivatives conjugated to bis (aminoethanethiol) (BAT) chelating ligand via a short propoxy spacer were synthesized and evaluated. In vitro binding assay showed that they displayed binding affinities to Aβ1-42 aggregates (Ki = 15.86-393.18 nM). In vitro autoradiography studies further confirmed the high and specific binding of [(99m)Tc]20 to β-amyloid plaques on brain sections of transgenic mice. Biodistribution study of [(99m)Tc]17-20 in normal mice displayed moderate initial brain uptake (0.96-1.55%ID/g at 2 min), and fast washed out from the brain (0.14-0.40%ID/g at 60 min), especially for [(99m)Tc]20 with a brain2min/brain60min ratio of 8.86. Taken together, these preliminary data suggested that [(99m)Tc]20 may be a potential imaging probe for detecting amyloid plaques in the brain., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

A variety of pyrimidinyl benzoxazoles, benzothiazoles and benzimidazoles linked by thio, methylthio and amino moieties were prepared and studied their antimicrobial and cytotoxic activities. The compound pyrimidinyl bis methylthio benzimidazole 22 was a potent antimicrobial agent particularly against Staphylococcus aureus (29 mm, MIC 12.5 μg/mL) and Penicillium chrysogenum (38 mm, MIC 12.5 μg/mL). The amino linked pyrimidinyl bis benzothiazole 24 exhibited cytotoxic activity on A549 cells with IC50 value of 10.5 μM., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

A set of substituted-[N'-(benzofuroxan-5-yl)methylene]benzohydrazides (4a-t), previously designed and synthesized, was experimentally assayed against Trypanosoma cruzi, the etiological agent of Chagas' disease, one of the most neglected tropical diseases. Exploratory data analysis, Hansch approach and VolSurf formalism were applied to aid the ligand-based design of novel anti-T. cruzi agents. The best 2D-QSAR model showed suitable statistical measures [n = 18; s = 0.11; F = 42.19; R(2) = 0.90 and Q(2) = 0.77 (SDEP = 0.15)], and according to the optimum 3D-QSAR model [R(2) = 0.98, Q(2) = 0.93 (SDEP = 0.08)], three latent variables explained 62% of the total variance from original data. Steric and hydrophobic properties were pointed out as the key for biological activity. Based upon the findings, six novel benzofuroxan derivatives (4u-z) were designed, synthesized, and in vitro assayed to perform the QSAR external prediction. Then, the predictability for the both models, 2D-QSAR (Rpred(2) = 0.91) and 3D-QSAR (Rpred(2) = 0.77), was experimentally validated, and compound 4u was identified as the most active anti-T. cruzi hit (IC50 = 3.04 μM)., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

A library of novel bis-heterocycles containing benzoxazolinone based 1,2,3-triazoles has been synthesized using click chemistry approach. The compound 3f exhibited potent selective COX-2 inhibition of 59.48% in comparison to standard drug celecoxib (66.36% inhibition). The compound 3i showed significant (p < 0.001, 50.95%), TNF-α inhibitory activity as compared to indomethacin (p < 0.001, 64.01%). The results of the carrageenan induced hind paw oedema showed that compounds 3a, 3f, 3i, 3o, and 3e exhibited potent anti-inflammatory activity in comparison to Indomethacin. The molecular docking studies revealed that 3i exhibits strong inhibitory effect due to the extra stability of the complex because of an extra π-π bond. The histopathology report showed that none of the compounds caused gastric ulceration., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

A general synthetic approach to two new series of methylenebisphosphonates: arylamino-2-ethane-1,1-diyl- and benzoxazole-2-methylenebisphosphonates is presented. Acid hydrolysis of selected BPs was undertaken to give the corresponding bisphosphonic acid (BP-acid). Next, the prediction of the permeability (hydrophobicity) of the target compounds was measured, by a combination of RP-HPLC and computational techniques, to study the capacity of transporting the molecule through cellular membranes. Cytotoxicity/growth inhibition of 50% (GI(50), mg/L) and antichronic inflammation properties of the products were evaluated. Later on, a comparison of the pharmacological results with water-octanol partition coefficients (log K(OW)) of the compounds was also reported., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)

A new series of 2-methoxy-2'-hydroxybenzanilide derivatives and their thioxo analogues have been synthesised and characterised by IR, NMR and elemental analysis. These compounds were investigated for their in vitro antimycobacterial activities against Mycobacterium tuberculosis 331/88, Mycobacterium avium 330/88, Mycobacterium kansasii 235/80, clinically isolated M. kansasii 6509/96 and the ability to act as in vitro isocitrate lyase inhibitors. The best ICL inhibitors were two compounds from the thiobenzanilide group (8f, 8m), which exhibited an inhibition potential that was equal to the standard compound, 3-nitropropionic acid. In addition, the best antimycobacterial properties were exhibited by benzanilide derivatives 6h, 6k and 6l with 5-Cl and 4' or 5' Cl/Br substitution. For all the thiobenzanilide derivatives tested, two conformers were observed in the NMR spectra, which is most likely due to the hindered rotation of the C-N bond., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)

A novel 6,8-dichloro [1,2,4]triazolo [3,4-b] [1,3]benzoxazole-3(2H)-thione 4 and its derivatives 5a and 5b are synthesized from 5,7-dichloro-2-hydrazinyl-1,3-benzoxazole 3, obtained by reaction of hydrazine hydrate with ethyl [(5,7-dichloro-1,3-benzoxazol-2-yl)sulfanyl]acetate 2. The newly synthesized compounds are characterized by analytical (1)H NMR, (13)C NMR, LC-MS mass spectrometry and elemental analysis. All synthesized compounds are screened for in vitro antioxidant and anthelmintic activities. In correlation to anthelmintic activity, compounds are subjected to molecular docking studies for the binding to β-Tubulin, target protein elite to the parasites. Compounds 3, 4 and 5a exhibited potential radical scavenging capacity with good anthelmintic activity. In molecular docking study also, compounds showed minimum binding energy and have good affinity toward the active pocket thus, they may be considered as good inhibitor of β-Tubulin., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)

N-myristoyltransferase (NMT) has been a promising new target for the design of novel antifungal agents with new mode of action. A series of benzoxazole and indole derivatives were designed and synthesized as isosteric analogues of benzoheterocyclic NMT Inhibitors. In vitro antifungal assay indicated that the benzoxazole derivatives were far more potent than the indoles. Molecular docking studies revealed that the hydrogen bonding interaction between the benzoheterocyclic core and NMT might be essential in the orientation of the inhibitor to a proper position. The antifungal activity of benzoxazole derivative 8f was comparable or superior to that of fluconazole, which can serve as a good starting point for further studies of structural diversity of the benzoheterocyclic NMT inhibitors., (2010 Elsevier Masson SAS. All rights reserved.)

For better understanding of the molecular interactions of inhibitors with CYP450 1A1, a series of benzoxazoles and benzothiazoles were analyzed by comparative molecular field analysis (CoMFA) and molecular docking. Two conformer-based alignment strategies were employed to construct reliable CoMFA models. The best CoMFA model yielded a predictive correlation coefficient r(2)(pred) value of 0.809. Furthermore, a three-dimensional model of CYP450 1A1 was generated by homology modeling using CYP450 1A2 as a template, and docking of 48 CYP450 1A1 inhibitors into the putative binding sites of the CYP450 1A1 were studied. The results obtained from this study will be helpful in the design of potentially active CYP450 1A1 inhibitors., (Copyright (c) 2009 Elsevier Masson SAS. All rights reserved.)

Hybrid vinylthio-, vinylsulfinyl-, vinylsulfonyl- and vinylketo-benzofuroxans developed as anti-trypanosomatid agents, against Trypanosoma cruzi and Leishmania spp., have showed low micromolar IC(50) values. The synthetic route to access to these derivatives was an efficient Wittig reaction performed in mild conditions with polymer-supported triphenylphosphine (PS-TPP). Additionally, the benzofurozan analogues, deoxygenated benzofuroxans, were prepared using PS-TPP as reductive reagent in excellent yields. The trypanosomicidal and leishmanocidal activities of the benzofuroxan derivatives were measured and also some aspects of their mechanism of action studied. In this sense, inhibition of mitochondrial dehydrogenases activities, production of intra-parasite free radicals and cruzipain inhibition were studied as biological target for the anti-trypanosomatid identified compounds. The trypanosomicidal activity could be the result of both the parasite-mitochondrion function interference and production of oxidative stress into the parasite.

A set of 2-benzylsulfanyl derivatives of benzoxazole was synthesized and evaluated for their in vitro antimycobacterial activity against Mycobacterium tuberculosis, non-tuberculous mycobacteria and multidrug-resistant M. tuberculosis. The activities were expressed as the minimum inhibitory concentration (MIC) in mmol/L. The substances showed similar activity against all tested strains. The lead compounds in the set, dinitro derivatives exhibited significant activity against both sensitive and resistant strains of M. tuberculosis and also against non-tuberculous mycobacteria. To facilitate drug design of benzoxazole as potential antituberculosis agent, we have explored the quantitative structure-activity relationship (QSAR). We demonstrated that lower lipophilicity has significant contribution to activity. Dinitrobenzylsulfanyl derivative of benzoxazole represents the promising small-molecule synthetic antimycobacterials.

A new series of 5(or 6)-nitro/amino-2-(substituted phenyl/benzyl)benzoxazole derivatives were synthesized and evaluated for antibacterial and antifungal activities against Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, Candida albicans and their drug-resistant isolate. Microbiological results indicated that the synthesized compounds possessed a broad spectrum of activity against the tested microorganisms at MIC values between > 400 and 12.5 microg/ml. The results against B. subtilis, P. aeruginosa, drug-resistant B. subtilis, drug-resistant E. coli, and C. albicans isolate for these kinds of structures are quite encouraging. The 2D-QSAR analysis of a set of newly and previously synthesized benzoxazoles tested for growth inhibitory activity against B. subtilis ATCC 6633 was performed by using the multivariable regression analysis. The activity contributions for substituent effects of these compounds were determined from the correlation equation for predictions of the lead optimization.

We describe here the synthesis and the binding interaction with sigma(1) and sigma(2) receptors of a series of new benzo[d]oxazol-2(3H)-one derivatives variously substituted on the N-benzyl moiety. The results of binding studies confirm the notion that the benzoxazolone moiety confers preference towards sigma(1) sites and establish that the ability to bind to sigma(1), but not to sigma(2) receptors, is strongly affected by the kind and the position of the substituents introduced in the N-benzyl ring. In fact, compounds with substitutions in para-position with atoms of Cl, H or F or with a CH(3) group exhibit a higher affinity for sigma(1) receptors than the corresponding ortho-substituted compounds. The highest affinity and selectivity, with K(i) values of 0.1 and 427 nM for sigma(1) and sigma(2) receptors, respectively, and a corresponding K(i)sigma(2)/K(i)sigma(1) selectivity ratio of 4270 were found for the Cl-substituted compound. These results indicate that benzo[d]oxazol-2(3H)-one derivatives are among the most selective and sigma(1) receptor-preferring ligands currently available.

The synthesis and antimicrobial activity of a new series of 2-(substitutedphenyl/benzyl)-5-[(2-benzofuryl)carboxamido]benzoxazole derivatives 3-12 were described. The in vitro antimicrobial activity of the compounds was determined against some Gram-positive, Gram-negative bacteria and fungi and their drug-resistant isolates in comparison with standard drugs. Antimicrobial results indicated that the synthesized compounds possessed a broad spectrum of activity with MIC values 500-15.625 microg/ml. In the series, the most active compound against Candida krusei and Candida albicans isolate is 8 with MIC value 31.25 microg/ml. However, it is one dilution less potent than the compared fluconazole. Some of the screened compounds exhibit significant activity, having MIC value as 31.25 microg/ml in Pseudomonas aeruginosa having same activity as Rifampicin. Furthermore, considering the worth of developing new antibacterial agents against drug-resistant P. aeruginosa the present study explores the structure-activity relationship analysis of 2-(substitutedphenyl/benzyl)-5-[(2-benzofuryl)carboxamido]benzoxazoles using 3D-common features pharmacophore hypotheses approach.

The synthesis and antimicrobial activity of a new series of 5-ethylsulphonyl-2-(substituted-phenyl/substituted-benzyl and/or phenylethyl)benzoxazole derivatives (3a-3t) except 3a, 3g, 3h, 3k [R.S. Pottorf, N.K. Chadha, M. Katkevies, V. Ozola, E. Suna, H. Ghane, T. Regberg, M.R. Player, Tetrahedron Lett. 44 (1) (2003) 175] were described. The in vitro antimicrobial activity of the compounds was determined against some Gram-positive, Gram-negative bacteria, a fungi Candida albicans and their drug-resistant isolates in comparison with standard drugs. Antimicrobial results indicated that the synthesized compounds possessed a broad spectrum of activity with MIC values 250-7.81 microg/ml. While all compounds are less potent than fluconazole against C. albicans, most of them are more potent than fluconazole against C. albicans isolate.

5-HT(3) receptor is an attractive target for the development of therapeutic agents for use in brain, heart and cancer diseases, and imaging agents for use in biomedical imaging technique PET. Benzoxazole derivatives are a novel class of 5-HT(3) receptor partial agonists with high binding affinity. Carbon-11 labeled benzoxazole derivatives have been synthesized as new potential PET radioligands for imaging 5-HT(3) receptor. The target tracers were prepared by N-[(11)C]methylation of their corresponding precursors using [(11)C]CH(3)OTf and isolated by HPLC purification procedure in 40-50% radiochemical yields, which were decay corrected to the end of bombardment (EOB), based on [(11)C]CO(2). The overall synthesis time was 20-25min from EOB. The radiochemical purity was >99%, and specific activity was in a range of 74-111 GBq/micromol at the end of synthesis (EOS).

A series of 12 new Mannich bases with chalcone core structure were synthesized as potential antineoplastic agents, via N-aminomethylation of two parent 6-(3-aryl-2-propenoyl)-2(3H)-benzoxazolones. The newly synthesized compounds as well as the chalcone prototypes were evaluated for cytotoxicity in the human pre-B-cell leukemia cell line BV-173 using the MTT-dye reduction assay. The tested compounds exhibited concentration-dependent cytotoxic effects at low micromolar concentrations. Ten of the Mannich bases characterized by significant activity in BV-173 were further evaluated against the chronic myeloid leukemia cell line K-562 and were found to suppress the growth of these cells at relatively higher concentrations as compared to the former tumor model. Selected Mannich bases induced programmed cell death in BV-173 at a concentration of 2.5muM as evidenced by the encountered DNA-laddering. Taken together our data suggest that the presented heterocyclic chalcone derived Mannich bases necessitate detailed pharmacological evaluation in order to define further the structure activity relationships, in a larger spectrum of tumor models and to elucidate the mechanisms implicated in the observed cytotoxic effects.

Some new 2-(benzyl/p-chlorobenzyl)-5-[(substituted-thienyl/phenyl/phenylthiomethyl/benzyl)carbonylamino]benzoxazole derivatives have been synthesized by reacting 5-amino-2-(benzyl/p-chlorobenzyl)benzoxazoles with appropriate carboxylic acid chlorides. The structures of the synthesized compounds were confirmed by IR, (1)H NMR and MASS spectral data. In vitro antimicrobial activities of the compounds were investigated using twofold serial dilution technique against different two Gram-positive, two Gram-negative bacteria and three Candida spp. in comparison with standard drugs. Microbiological results indicated that the newly synthesized 2-(benzyl/p-chlorobenzyl)-5-[(substituted-thienyl/phenyl/phenylthiomethyl/benzyl)carbonylamino]benzoxazole derivatives (3-12) possessed a broad spectrum of activity having MIC values of 6.25-100 microg/ml against the tested microorganisms. Especially, with an MIC value of 6.25 microg/ml, 2-(p-chlorophenyl)-5-[(2,5-dimethylphenyl)carbonylamino]benzoxazole 4 displayed the same activity against Candida albicans as the standard drug clotrimazole.

In an effort to establish new candidates with improved antineoplastic, anti-HIV-1 and antimicrobial activities we report here the synthesis and in vitro biological evaluation of various series of 2-substituted benzoxazoles: 2-[(Arylhydrazono, arylidene, cycloalkylidene and N-substituted thiocarbamoyl)cyanomethyl]-benzoxazoles(2-4 and 7, respectively); 2-[(4- or 5-oxothiazoliden-2-yliden)benzoxazoles (5 and 6) and 2-(4-amino-3-substituted-2-thioxo-2,3-dihydrothiazol-5-yl)benzoxazoles (8), together with the synthesis of some substituted 3H-pyrido[2,1-b]benzoxazoles (9-11). The absolute configuration of compound 3b was determined by X-ray crystallography. The results of the in vitro anticancer screening revealed that some of the tested compounds exhibited broad spectrum antitumor activity. The most active compounds are 2a, 3b, 8a and 8d, their GI50 MG-MID values: 37.7, 19.1, 20.0 and 15.8 microM; TGI MG-MID values: 75.9, 53.7, 53.7, and 58.9 microM; and LC50 MG-MID values: 97.7, 93.3, 89.1 and 93.3 microM, respectively. The in vitro microbiological data showed that compound 7c was the most active against Staphylococcus aureus (minimal inhibitory concentration (MIC)<12.5 microg ml(-1). While compounds 5, 8a, and 8d were the most active against Bacillus subtilis (MIC values<12.5 microg ml(-1)). On the other hand, compounds 5 and 7c were the most active against Escherichia coli (MIC<25 microg ml(-1)), their activity is about half the activity of ampicillin and streptomycin . In addition, compound 4b and 7c were the most active against Pseudomonas aeruginosa (MIC<25, 50 microg ml(-1)). Compound 4b was two times as active as ampicillin and streptomycin while compound 7c was active as both. The results of antimycotic activity indicated that, Compound 7c showed mild activity against Candida albicans when compared with clotrimazole (MIC<100 microg ml(-1)). In vitro HIV-1 testing revealed that compound 7a displayed moderate anti-HIV-1 activity (maximum % cell protection, 36.6 at 2 x 10(-5) microM).

A series of 6-amino-2-phenyl-4H-3,1-benzoxazin-4-one aminoacyl and dipeptidyl derivatives, in which aminoacids and dipeptides are linked to the benzoxazinone moiety via an amide bond, were synthesized and tested in vitro for their inhibitory activity towards human leukocyte elastase (HLE). When compared to their values without inhibitors, the residual enzymatic activities decrease with time, indicating a time-dependent inhibition. The most potent inhibitions were obtained when Z-Arg-(Pmc), Z-Val-Phe, Z-Ala-Val or Z-Val-Ala are linked to the 6-amino group. Twenty-five new compounds were synthesized.

Some novel benzoxazolylethoxypiperidones have been synthesized and their antibacterial activity against streptococcus faecalis, bacillus subtilis, escherichia coli, staphylococcus aureus aand pseudomonas aeruginosa and antifungal activity against Candida-6, Candida albicans, Aspergillus niger, Candida-51 and Aspergillus flavus were evaluated. Compounds 37, 38 and 39 exerted potent in vitro antibacterial activity against Streptococcus faecalis while compounds 40 and 41 exhibited potent in vitro antifungal activity against Candida-51.

A series of multisubstituted benzoxazoles, benzimidazoles, and benzothiazoles (5-7) as non-nucleoside fused isosteric heterocyclic compounds was synthesized and tested for their antibacterial activities against various Gram-positive and Gram-negative bacteria and antifungal activity against the fungus Candida albicans. Microbiological results indicated that the synthesized compounds possessed a broad spectrum of activity against the tested microorganisms at MIC values between 100 and 3.12 microg/ml. Structure-activity relationships (SAR) studies revealed that benzothiazole ring system enhanced the antimicrobial activity against Staphylococcus aureus. In these sets of non-nucleoside fused heterocyclic compounds electron withdrawing groups at position 5 of the benzazoles increased the activity against C. albicans.