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A series of benzoxazole-based amides and sulfonamides were synthesized and evaluated for their human peroxisome proliferator-activated receptor (PPAR)α and PPARγ activity. All tested compounds showed a dual antagonist profile on both PPAR subtypes; based on transactivation results, seven compounds were selected to test their in vitro antiproliferative activity in a panel of eight cancer cell lines with different expression rates of PPARα and PPARγ. 3f was identified as the most cytotoxic compound, with higher potency in the colorectal cancer cell lines HT-29 and HCT116. Compound 3f induced a concentration-dependent activation of caspases and cell-cycle arrest in both colorectal cancer models. Docking experiments were also performed to shed light on the putative binding mode of this novel class of dual PPARα/γ antagonists., (© 2024 Deutsche Pharmazeutische Gesellschaft.)

In an attempt to identify potential anticancer agents for non-small-cell lung cancer (NSCLC) targeting sirtuin 1 (SIRT1), the synthesis of a new series of benzoxazoles (3a - i) was carried out through a facile and versatile synthetic route. The compounds were evaluated for their cytotoxic effects on A549 human lung adenocarcinoma and NIH/3T3 mouse embryonic fibroblast cells using the MTT assay. 2-[(5-Nitro-1H-benzimidazol-2-yl)thio]-N-(2-methylbenzoxazol-5-yl)acetamide (3e) and 2-[(5-chloro-1H-benzimidazol-2-yl)thio]-N-(2-methylbenzoxazol-5-yl)acetamide (3g) were the most potent and selective anticancer agents in this series against the A549 cell line, with IC 50 values of 46.66 ± 11.54 and 55.00 ± 5.00 µM, respectively. The flow cytometry-based apoptosis detection assay was performed to determine their effects on apoptosis in A549 cells. Both compounds induced apoptosis in a dose-dependent manner. The effects of compounds 3e and 3g on SIRT1 activity were determined. On the basis of in vitro studies, it was observed that compound 3g caused a significant decrease in SIRT1 levels in a dose-dependent manner, whereas compound 3e increased the SIRT1 levels. According to molecular docking studies, the substantial alteration in the type of action could be attributed to the difference between the interactions of compounds 3e and 3g with the same residues in the active site of SIRT1 (PDB code: 4IG9). On the basis of in silico ADME (absorption, distribution, metabolism, and excretion) studies, these compounds are predicted to possess favorable ADME profiles. According to the in vitro and in silico studies, compounds 3e and 3g, small-molecule SIRT1 modulators, were identified as potential orally bioavailable anticancer agents for the targeted therapy of NSCLC., (© 2020 Deutsche Pharmazeutische Gesellschaft.)

In this study, novel halogenated chalcones, 6-(3-halogenated phenyl-2-propen-1-one)-2(3H)-benzoxazolones (2a-n), were synthesized for the first time (except 2a), and their chemical structures were characterized by 1 H nuclear magnetic resonance (NMR), 13 C NMR, and high-resolution mass spectrometry spectra. Cytotoxic activities and carbonic anhydrase (CA) inhibitory effects of the compounds were studied to identify new possible drug candidate molecules. Cytotoxicity results pointed out that compound 2m, 6-[3-(3-bromophenyl)-2-propenoyl]-2(3H)-benzoxazolone, had the highest cytotoxicity (CC 50 ) and potency selectivity expression (PSE) values. Thus, compound 2m can be considered as a lead compound of the series in terms of cytotoxicity. When the CA inhibition results of the compounds were evaluated, it was found that the K i values of the compounds ranged from 30.5 ± 11.3 to 65.5 ± 25.6 µM toward hCA I, and they ranged from 7.3 ± 1.8 to 58.8 ± 12.3 µM toward hCA II. However, the K i values of the reference drug, acetazolamide (AZA), were 30.2 ± 7.8 and 4.4 ± 0.6 μM toward hCA I and hCA II, respectively. According to the results obtained, compounds 2a-n had lower K i values than AZA, whereas compounds 2a, 2b, 2e-g, 2l, and 2n had similar K i values, compared with AZA. So, the compounds 2a, 2b, 2e-g, 2l, and 2n can be considered as lead molecules of this series for further considerations., (© 2020 Deutsche Pharmazeutische Gesellschaft.)

Novel series of benzoxazoles 4 a-f -16 were designed, synthesized, and evaluated for anticancer activity against HepG2, HCT-116, and MCF-7 cells. HCT-116 was the most sensitive cell line to the influence of the new derivatives. In particular, compound 5 e was found to be the most potent against HepG2, HCT-116, and MCF-7 with IC 50  = 4.13 ± 0.2, 6.93 ± 0.3, and 8.67 ± 0.5 µM, respectively. Compounds 5 c , 5 f , 6 b , 5 d , and 6 c showed the highest anticancer activities against HepG2 cells with IC 50 of 5.93 ± 0.2, 6.58 ± 0.4, 8.10 ± 0.7, 8.75 ± 0.7, and 9.95 ± 0.9 µM, respectively; HCT-116 cells with IC 50 of 7.14 ± 0.4, 9.10 ± 0.8, 7.91 ± 0.6, 9.52 ± 0.5, and 12.48 ± 1.1 µM, respectively; and MCF-7 cells with IC 50 of 8.93 ± 0.6, 10.11 ± 0.9, 12.31 ± 1.0, 9.95 ± 0.8, and 15.70 ± 1.4 µM, respectively, compared with sorafenib as a reference drug with IC 50 of 9.18 ± 0.6, 5.47 ± 0.3, and 7.26 ± 0.3 µM, respectively. The most active compounds 5 c-f and 6 b,c were further evaluated for their vascular endothelial growth factor receptor-2 (VEGFR-2) inhibition. Compounds 5 e and 5 c potently inhibited VEGFR-2 at lower IC 50 values of 0.07 ± 0.01 and 0.08 ± 0.01 µM, respectively, compared with sorafenib (IC 50  = 0.1 ± 0.02 µM). Compound 5 f potently inhibited VEGFR-2 at low IC 50 value (0.10 ± 0.02 µM) equipotent to sorafenib. Our design was based on the essential pharmacophoric features of the VEGFR-2 inhibitor sorafenib. Molecular docking was performed for all compounds to assess their binding pattern and affinity toward the VEGFR-2 active site., (© 2019 Deutsche Pharmazeutische Gesellschaft.)

A novel series of benzoxazole derivatives containing 1,2,4-triazolone (5a-m) was designed. These compounds were synthesized in order to screen their anticonvulsant activities by the maximal electroshock seizure (MES) model and the subcutaneous pentylenetetrazole (sc-PTZ) seizure model in mice. The rotarod test was used to evaluate their neurotoxicities. Most of the compounds showed anti-MES activities at 100 and 300 mg/kg. Compound 5f, which showed potential anticonvulsant activity in the MES model with ED 50 values of 22.0 mg/kg, was considered as the most promising one in this study. It exhibited greater safety than that of carbamazepine and valproate regarding neurotoxicity. The efficacy of compound 5f in inhibiting the tonic seizures and death induced by the convulsants 3-mercaptopropionic acid and BIC was also verified. In an enzyme-linked immunosorbent assay, compound 5f and the positive drug phenytoin significantly increased the γ-aminobutyric acid (GABA) level in the mouse brain. Further, pretreatment with an inhibitor of the GABA synthesizing enzyme dramatically raised the ED 50 value of 5f in the MES model. These results confirmed that the compound 5f plays its anticonvulsive action via regulating the GABA function in the brain. Also, a docking study of the compound 5f in the benzodiazepine (BZD) binding site of the GABA A receptor confirmed possible binding of the compound 5f with BZD receptors., (© 2019 Deutsche Pharmazeutische Gesellschaft.)

A series of N-(2-(3,5-dimethoxyphenyl)benzoxazole-5-yl)benzamide derivatives (3am) was synthesized and evaluated for their in vitro inhibitory activity against COX-1 and COX-2. The compounds with considerable in vitro activity (IC 50  < 1 μM) were evaluated in vivo for their anti-inflammatory potential by the carrageenan-induced rat paw edema method. Out of 13 newly synthesized compounds, 3a, 3b, 3d, 3g, 3j, and 3k were found to be the most potent COX-2 inhibitors in the in vitro enzymatic assay, with IC 50 values in the range of 0.06-0.71 μM. The in vivo anti-inflammatory activity of these six compounds (3a, 3b, 3d, 3g, 3j, and 3k) was assessed by the carrageenan-induced rat paw edema method. Compounds 3d (84.09%), 3g (79.54%), and 3a (70.45%) demonstrated significant anti-inflammatory activity compared to the standard drug ibuprofen (65.90%) and were also found to be safer than ibuprofen, by ulcerogenic studies. A docking study was done using the crystal structure of human COX-2, to understand the binding mechanism of these inhibitors to the active site of COX-2., (© 2018 Deutsche Pharmazeutische Gesellschaft.)

A series of N-substituted-5-chloro-2(3H)-benzoxazolone derivatives were synthesized and evaluated for their acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) inhibitory, and antioxidant activities. The structures of the title compounds were confirmed by spectral and elemental analyses. The cholinesterase (ChE) inhibitory activity studies were carried out using Ellman's colorimetric method. The free radical scavenging activity was also determined by in vitro ABTS (2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)) assay. The biological activity results revealed that all of the title compounds displayed higher AChE inhibitory activity than the reference compound, rivastigmine, and were selective for AChE. Among the tested compounds, compound 7 exhibited the highest inhibition against AChE (IC 50  = 7.53 ± 0.17 μM), while compound 11 was found to be the most active compound against BuChE (IC 50  = 17.50 ± 0.29 μM). The molecular docking study of compound 7 showed that this compound can interact with the catalytic active site (CAS) of AChE and also has potential metal chelating ability and a proper log P value. On the other hand, compound 2 bearing a methyl substituent at the ortho position on the phenyl ring showed better radical scavenging activity (IC 50  = 1.04 ± 0.04 mM) than Trolox (IC 50  = 1.50 ± 0.05 mM)., (© 2018 Deutsche Pharmazeutische Gesellschaft.)

A new series of benzothiazoles and benzoxazoles was synthesized using 4-benzothiazol-2-yl-phenylamine and 4-benzoxazol-2-yl-phenylamine as starting materials. All the prepared compounds were evaluated for their antitumor activities against human breast cancer cell lines, MCF-7 and MDA-231, using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability analysis. Almost all the tested compounds revealed potent antitumor activity, especially the N-methyl piperazinyl substituted derivatives 6f and 6c, which displayed the most potent inhibitory activity with IC50 values ranging from 8 to 17 nM. Docking the synthesized compounds into the epidermal growth factor receptor (EGFR), which is highly expressed in breast cancer, was employed to explore the possible interactions of these compounds with the EGFR. The activity of the reported compounds supports its clinical promise as a component of therapeutic strategies for cancer, for which high concentrations of chemotherapeutic agents are always a major limitation., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A series of PF-8380 analogs, a recently developed autotaxin inhibitor, was explored. Inhibition of autotaxin by these analogs, as well as by all PF-8380 synthetic intermediates, shows the importance of meta-dichlorobenzyl and benzo[d]oxazol-2(3H)-one fragments. However, analogs 8 and 9, bearing only the benzo[d]oxazol-2(3H)-one moiety, are more cytotoxic on the LN229 glioblastoma cell line than PF-8380 and temozolomide (TMZ)., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Myeloperoxidase (MPO), a heme protein expressed by polymorphonuclear leukocytes, generates potent oxidants which are proposed to contribute to tissue damage during inflammation and certain pathogenesis such as neurodegenerative disorders. In this study, twenty omega-[2-oxo-3H-benzoxazol-3-yl]-N-phenylacetamide and propionamide derivatives having substituents of different lipophilic and electronic nature on the N-phenyl ring were synthesized to evaluate the inhibitory effects on in vitro leukocyte MPO chlorinating activity. The most active compounds in the series were the derivatives bearing 2-methyl and 4-nitro substituent on the N-phenyl ring.

In this study, a series of twelve novel 5-[2-(morpholin-4-yl)acetamido] and/or 5-[2-(4-substituted pip-erazine-1-yl)acetamido]-2-(p-substituted phenyl]benzoxazole derivatives have been synthesized and their structures were confirmed by IR, (1)H NMR, and mass spectral data. These compounds were prepared by reacting 5-(2-chloroacetamido)-2-(4-p-substituted-phenyl)benzoxazoles, which were obtained by using 5-amino-2-[p-substituted-phenyl]benzoxazoles with chloroacetyl chloride, in the presence of morpholine or 1-substituted piperazines. All synthesized compounds 3-14 were tested by using the method of twofold serial dilution technique for in vitro activities against certain strains of Gram-positive, Gram-negative bacteria as well as the yeasts Candida albicans, Candida krusei, and Candida glabrata in comparison with standard drugs. Microbiological results showed that the newly synthesized compounds possessed a broad spectrum of activity, showing MIC values of 3.12-50 mug/mL against the Candida species.

The synthesis of a novel series of Mannich bases of 5-/6-acyl-5-methyl-2-benzoxazolinones has been described. The structures attributed to compounds 2a, 3a, 4a, 4b, 9a, 9b, 5a-5g, 6a-6g, 10a, 10g, 11a, 11g have been elucidated using IR and (1)H NMR spectroscopic techniques besides elemental analysis. The compounds have been evaluated for their in vivo analgesic and antiinflammatory activities using the p-benzoquinone-induced writhing test and the carrageenan hind paw oedema test in mice, respectively. In addition, the ulcerogenic effects of the compounds were determined. Among the tested derivatives most promising results were obtained for the compounds bearing a 6-(4-chlorobenzoyl) at C-6 position and 2-/4-fluorophenyl at C-3 position of 2-benzoxazolinone ring (11c, 11d).

A series of 23 new 2-[p-substituted-benzyl]-5-[p-substituted-phenyl/benzyl-carbonylamino]benzoxazole derivatives has been synthesized by reacting 5-amino-2-[p-substituted-benzyl]benzoxazoles with the appropriate carboxylic acid chlorides. The structures of the synthesized compounds were confirmed by IR and (1)H-NMR spectral data. Antimicrobial activities of the compounds were investigated using the twofold serial dilution technique against two gram-positive and two gram-negative bacteria and three Candida species in comparison with standard drugs. Microbiological results indicated that the newly synthesized 2-[p-substituted-benzyl]-5-[p-substituted-phenyl/benzyl-carbonylamino]benzoxazole derivatives (3-25) possessed a broad spectrum of activity, showing MIC values of 6.25-200 microg/mL against the gram-positive and gram-negative microorganisms tested. Moreover, they showed significant antifungal activity with MIC values of 3.12-100 microg/mL against the Candida species tested. Especially, with a MIC value of 3.12 microg/mL, 2-benzyl-5-[p-bromobenzyl-carbonylamino]benzoxazole 9 displayed the same activity against C. glabrata as the standard drug myconazol.

In this study, a series of (7-acyl-5-chloro-2-oxo-3H-benzoxazol-3-yl)alkanoic acid derivatives were synthesized and evaluated for their analgesic and anti-inflammatory activities by using the p-benzoquinone-induced writhing test and the carrageenan hind paw edema model, respectively. Acetic acid-induced peritoneal capillary permeability test and serotonin-induced hind paw edema test were also employed for the most active compounds. The test results indicated that (7-acyl-2-oxo-3H-benzoxazol-3-yl)alkanoic acids (Compounds 6 a-c, 8 a-c, 10 a-c) were equally or more potent analgesic and anti-inflammatory agents than aspirin and indomethacin respectively. The compounds 8a and 8c, but not 8b have the longest carbon chain on alkanoic acid moiety did not induce gastric lesion in mice.

New 2-[p-substituted-phenyl ]benzoxazol-5-yl-arylcarboxyamides derivatives have been synthesized by reacting 5-amino-2-[p-substituted-phenyl ]benzoxazoles with substituted-arylcarboxylic acid chlorides. The structures of the synthesized compounds were confirmed by IR and (1)H NMR spectral data. Antimicrobial activities of the compounds were investigated using the two-fold serial dilution technique against different Gram-positive and Gram-negative bacteria and the yeast C. albicans in comparison with standard drugs. Microbiological results indicated that the synthesized compounds possess a broad spectrum of activity, having an MIC value of 25-200 microg/mL at molar concentration values of 3.45 x 10(-5) and 5.74 x 10(-4) against the tested microorganisms.

New 1-arylpiperazine (series d-f) and 1,2,3,4-tetrahydroisoquinoline (series g) derivatives of 1,4-benzoxazin-3(4H)-one 1, 1,2-benzoxazolin-3-one 2, and 1,3-benzoxazolin-2,4-dione 3 with an n-butyl chain were synthesized in order to explore the effect of spacer elongation on their binding affinity and in vivo functional activity at 5-HT1A and 5-HT2A receptors in comparison with trimethylene analogues (a, bc). 5-HT1A receptor binding constants of derivatives 1d-g, 2d-f, and 3d-f were very high (Ki = 1.25-54 nM), and 5-HT2A affinities were maintained at a similar, high level (Ki = 27-85 nM) for series d and e, and moderate (Ki = 246-495 nM) for series f. In respect of a spacer, the obtained results showed either no effect or a slight increase in the 5-HT1A/5-HT2A affinity in case of derivatives of 1 and 2, respectively. A striking effect was observed for derivatives 3d and 3f, whose 5-HT1A affinity was reinforced by two orders of magnitude with a simultaneous decrease in 5-HT2A binding constants in comparison with trimethylene analogues. As shown by X-ray crystallography, this phenomenon may be attributed to the position of non-carbonyl oxygen atom in the amide moiety. In vivo studies demonstrated that compounds 1e-g, 2d-f, and 3f behaved like typical postsynaptic 5-HT1A receptor antagonists, whereas 3d and 3e might be qualified as their potential partial agonists. Moreover, 1e, 2e, and 3e demonstrated 5-HT2A receptor antagonistic properties. Of the tested compounds, two derivatives showed some very outstanding properties: 3e may be regarded as a potential anxiolytic and/or antidepressant agent, while 3f as a new potent 5-HT1A antagonist.

Twenty-two new 3-[2-(2-and/or 4-pyridyl)ethyl]benzoxazolinone and oxazolo[4,5-b]pyridin-2-one derivatives have been synthesized by reacting 2- and/or 4-vinylpyridine and appropriate benzoxazolinones and oxazolo[4,5-b]pyridine-2-one. Their chemical structures have been proven by IR. 1H-NMR, 13C-NMR, mass spectroscopy, and elemental analysis. The analgesic activities of these compounds were investigated by a modified Koster's Test. Test results revealed that, at 100 mg/kg dose level, most of the compounds showed significant analgesic activities when compared to aspirin. Therefore the compounds were screened for their antiinflammatory activities using the carrageenan hind paw edema test. Compounds 1, 7, 10, 11, 12, 13, 15, 18, 20, 21 were found more active than indomethacine. In gastric ulceration studies gastrointestinal bleeding was not observed at 100 mg/kg dose level in compounds 1 and 2.

Syntheses of substituted, especially of fluoro substituted benzoxathiole 1,1-dioxides, are described. These derivatives were transformed via the Peterson olefination into substituted 2-alkylidene derivatives 27. Diels-Alder reactions of 27 with 1,1-dimethoxy- and 1-methoxy-3-trimethylsiloxy-1,3-butadiene (30, 32) gave sulfone analogues 31 of griseofulvin (named sulfogriseofulvins). From Z-27, a number of cis-isomers with the relative stereochemistry of griseofulvin (cis-31) was prepared, and from E-isomers of 27, compounds (trans-31) with relative stereochemistry of epigriseofulvin were obtained. Some related compounds (33, 38) are synthesized by slight modifications. The stereochemistry is established by spectroscopic methods and crystal structure analyses. The compounds 31 were tested against three species of dermatophytes. The biological activities were all significantly lower than that of griseofulvin.

2-Vinylbenzoxazole (3) is obtained by condensation of acrylic acid with 2-aminophenol in a mixture of phosphorus pentoxide/methansulfonic acid. Interaction of 3 with N-, O-, and C-nucleophiles yields 2-substituted 2-ethyl-benzoxazoles. Compounds 8a, 8b and 8e show analgetic activity in mice. Moreover, fungicide, insecticide and nematocide activity of some compounds is found.

In our previous study, the antimicrobial activities of 16 new compounds synthetized by reacting 2-benzoxazolinones with derivatives of piperidine were determined. In this study, the analgesic activities of these compounds, using modified Koster's test is investigated. The analgesic activities of these compounds are higher than that of O-acetyl salicilic acid.