Synthesis and molecular docking simulation of new benzimidazole-thiazole hybrids as cholinesterase inhibitors.

Dementia is a cognitive disturbance that is generally correlated with central nervous system diseases, especially Alzheimer's disease. The limited number of medications available is insufficient to improve the lifestyle of the patients suffering from this disease. Thus, new benzimidazole-thiazole hybrids (3-10) were designed and synthesized as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory agents. The in vitro evaluation displayed that the derivatives 4b, 4d, 5b, 6a, 7a, and 8b demonstrated dual inhibitory efficiency against both AChE with IC50 ranging from 4.55 to 8.62 µM and BChE with IC50 ranging from 3.50 to 8.32 µM. By analyzing the Lineweaver-Burk plot, an uncompetitive form of inhibition was determined for the highly active compound 4d, revealing its inhibition type. The human telomerase reverse transcriptase-immortalized retinal pigment epithelial cell line was used to ensure the safety of the most potent cholinesterase inhibitors. Furthermore, compounds 4b, 4d, 5b, 6a, 7a, and 8b were evaluated for their neuroprotective and antioxidant properties, as well as their ability to suppress COX-2. The results demonstrated that compounds 4d, 5b, and 8b presented significant neuroprotection efficiency against H2 O2 -induced damage in SH-SY5Y cells with % cell viability of 67.42 ± 7.90%, 62.51 ± 6.71%, and 72.61 ± 8.10%, respectively, while the tested candidates did not reveal significant antioxidant activity. Otherwise, compounds 4b, 6a, 7a, and 8b displayed outstanding COX-2 inhibition effects with IC50 ranging from 0.050 to 0.080 µM relative to celecoxib (IC50 = 0.050 µM). In addition, molecular docking was carried out for the potent benzimidazole-thiazole hybrids with the active sites of both AChE (PDB ID: 4EY7) and BChE (PDB code: 1P0P). The tested candidates fit well in the active sites of both portions, with docking scores ranging from -8.65 to -6.64 kcal/mol (for AChE) and -8.71 to -7.73 kcal/mol (for BChE). In silico results show that the synthesized benzimidazole-thiazole hybrids have good physicochemical and pharmacokinetic properties with no Lipinski rule violations. The preceding results exhibited that compound 4d could be used as a new template for developing more significant cholinesterase inhibitors in the future.

Synthesis of aspirin-curcumin mimic conjugates of potential antitumor and anti-SARS-CoV-2 properties.

Series of piperidone-salicylate conjugates were synthesized through the reaction of 3E,5E-bis(arylidene)-4-piperidones with the appropriate acid chloride of acetylsalicylate in the presence of triethylamine. All the synthesized conjugates reveal antiproliferative properties against A431 (squamous skin) cancer cell line with potency higher than that of 5-fluorouracil. Many of the synthesized agents also exhibit promising antiproliferative properties against HCT116 (colon) cancer cell line, of which 5o and 5c are the most effective with 12.9, 9.8 folds potency compared with Sunitinib. Promising activity is also shown against MCF7 (breast) cancer cell line with 1.19, 1.12 folds relative to 5-fluorouracil. PI-flow cytometry of compound 5c supports the arrest of cell cycle at G1-phase. However, compound 5o and Sunitinib arrest the cell cycle at S-phase. The synthesized conjugates can be considered as multi-targeted tyrosine kinase inhibitors due to the promising properties against VEGFR-2 and EGFR in MCF7 and HCT116. CDOCKER studies support the EGFR inhibitory properties. Compounds 5p and 5i possessing thienylidene heterocycle are anti-SARS-CoV-2 with high therapeutic indices. Many of the synthesized agents show enhanced COX-1/2 properties than aspirin with better selectivity index towards COX-2 relative to COX-1. The possible applicability of the potent candidates discovered as antitumor and anti-SARS-CoV-2 is supported by the safe profile against normal (non-cancer, RPE1 and VERO-E6) cells.

New quinoline-triazole conjugates: Synthesis, and antiviral properties against SARS-CoV-2.

At present therapeutic options for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are very limited. We designed and synthesized three sets of small molecules using quinoline scaffolds. A series of quinoline conjugates (10a-l, 11a-c, and 12a-e) by incorporating 1,2,3-triazole were synthesized via a modified microwave-assisted click chemistry technique. Among the synthesized conjugates, 4-((1-(2-chlorophenyl)-1H-1,2,3-triazol-4-yl)methoxy)-6-fluoro-2-(trifluoromethyl)quinoline (10g) and 6-fluoro-4-(2-(1-(4-methoxyphenyl)-1H-1,2,3-triazol-4-yl)ethoxy)-2-(trifluoromethyl)quinoline (12c) show high potency against SARS-CoV-2. The selectivity index (SI) of compounds 10g and 12c also indicates the significant efficacy compared to the reference drugs.

3-Alkenyl-2-oxindoles: Synthesis, antiproliferative and antiviral properties against SARS-CoV-2.

Sets of 3-alkenyl-2-oxindoles (6,10,13) were synthesized in a facile synthetic pathway through acid dehydration (EtOH/HCl) of the corresponding 3-hydroxy-2-oxoindolines (5,9,12). Single crystal (10a,c) and powder (12a,26f) X-ray studies supported the structures. Compounds 6c and 10b are the most effective agents synthesized (about 3.4, 3.3 folds, respectively) against PaCa2 (pancreatic) cancer cell line relative to the standard reference used (Sunitinib). Additionally, compound 10b reveals antiproliferative properties against MCF7 (breast) cancer cell with IC50 close to that of Sunitinib. CAM testing reveals that compounds 6 and 10 demonstrated qualitative and quantitative decreases in blood vessel count and diameter with efficacy comparable to that of Sunitinib, supporting their anti-angiogenic properties. Kinase inhibitory properties support their multi-targeted inhibitory activities against VEGFR-2 and c-kit in similar behavior to that of Sunitinib. Cell cycle analysis studies utilizing MCF7 exhibit that compound 6b arrests the cell cycle at G1/S phase while, 10b reveals accumulation of the tested cell at S phase. Compounds 6a and 10b reveal potent antiviral properties against SARS-CoV-2 with high selectivity index relative to the standards (hydroxychloroquine, chloroquine). Safe profile of the potent synthesized agents, against normal cells (VERO-E6, RPE1), support the possible development of better hits based on the attained observations.

Design, synthesis, biological evaluation, QSAR analysis and molecular modelling of new thiazol-benzimidazoles as EGFR inhibitors.

Heterocyclic rings such as thiazole and benzimidazole are considered as privileged structures, since they constitute several FDA-approved drugs for cancer treatment. In this work, a new set of 2-(2-(substituted) hydrazinyl)-4-(1-methyl-1H-benzo[d]imidazol-2-yl) thiazoles 4a-q were designed as epidermal growth factor receptor (EGFR) inhibitors and synthesized using concise synthetic methods. The new target compounds have been evaluated in vitro for their suppression activity against EGFR TK. Compounds 4n, 4h, 4i, 4a and 4d exhibited significant potency in comparison with erlotinib which served as a reference drug (IC50, 71.67-152.59 nM; IC50 erlotinib, 152.59 nM). Furthermore, MTT assay revealed that compounds 4j, 4a, 4f, 4h, 4n produced the most promising cytotoxic potency against the human breast cancer cell line (MCF-7) (IC50; 5.96-11.91 µM; IC50 erlotinib; 4.15 µM). Compound 4a showed promising activity as EGFR TK inhibitor as well as anti-breast cancer agent. In addition, 4a induced apoptotic effect and cell cycle arrest at G2/M phase preventing the mitotic cycle in MCF-7 cells. Moreover, 4a upregulated the oncogenic parameters; caspase-3, p53, Bax/Bcl-2 as well as it inhibited the level of PARP-1 enzyme. QSAR study was carried out for the new derivatives and it revealed the goodness of the models. Furthermore, molecular docking studies represented the binding modes of the promising compounds in the active pocket of EGFR.

Synthesis and 2D-QSAR study of dispiropyrrolodinyl-oxindole based alkaloids as cholinesterase inhibitors.

In this work, we describe the regioselective synthesis of some new dispiro[indene-2,3'-pyrrolidine-2',3″-indoline]-1,2″(3H)-dione 4-29 attributable to the previously described methods. All the new chemical entities were assessed in-vitro as inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes; while no significant inhibitory activity for the tested compounds were assigned on AChE, compounds 4, 27, 29, 28 and 15 were the most active against BChE enzyme with IC50 = 13.7 µM, 21.8 µM, 22.1 µM, 22.9 µM and 24.9 µM respectively compared to Donepezil (IC50 = 0.72 µM). Compound 4 was found to have a mixed type mode of inhibition, the bioactivity of the new chemical entities (N = 26, n = 5, R2 = 0.893, R2 cvOO = 0.831, R2 cvMO = 0.838, F = 33.32, s2 = 0.003) was elucidated via a statistically significant QSAR model utilizing CODESSA-Pro software that validated the observed results.

Synthesis and 2D-QSAR Study of Active Benzofuran-Based Vasodilators.

A new series of 2-alkyloxy-pyridine-3-carbonitrile-benzofuran hybrids (4a-x) was synthesized. All the new derivatives were examined via the standard technique for their vasodilation activity. Some of the investigated compounds exhibited a remarkable activity, with compounds 4w, 4e, 4r, 4s, 4f and 4g believed to be the most active hits in this study with IC50 values 0.223, 0.253, 0.254, 0.268, 0.267 and 0.275 mM, respectively, compared with amiodarone hydrochloride, the reference standard used (IC50 = 0.300 mM). CODESSA PRO was employed to obtain a statistically significant 2-Dimensional Quantitative Structure Activity Relationship (2D-QSAR) model describing the bioactivity of the newly synthesized analogs (N = 24, n = 4, R² = 0.816, R²cvOO = 0.731, R²cvMO = 0.772, F = 21.103, s² = 6.191 × 10-8).

Rational design, synthesis and 2D-QSAR study of novel vasorelaxant active benzofuran-pyridine hybrids.

Reaction of 3-aryl-1-(benzofuran-2-yl)-2-propen-1-ones 3a-c with malononitrile in the presence of sufficient amount of sodium alkoxide in the corresponding alcohol proceeds in a regioselective manner to afford 2-alkoxy-4-aryl-6-(benzofuran-2-yl)-3-pyridinecarbonitriles 4-37, which also obtained by treating ylidenemalononitriles 6a-q with 2-acetylbenzofuran 1 in the presence of sufficient amount of sodium alkoxide in the corresponding alcohol. The new chemical entities showed significant vasodilation properties using isolated thoracic aortic rings of rats pre-contracted with norepinephrine hydrochloride standard technique. Compounds 11, 16, 21, 24 and 30 exhibited remarkable activity compared with amiodarone hydrochloride the reference standard used in the present study. CODESSA-Pro software was employing to obtain a statistically significant QSAR model describing the bioactivity of the newly synthesized analogs (N=31, n=5, R(2)=0.846, R(2)cvOO=0.765, R(2)cvMO=0.778, F=27.540. s(2)=0.002).

Rational design, synthesis and molecular modeling studies of novel anti-oncological alkaloids against melanoma.

3D-pharmacophore and 2D-QSAR modeling studies describe the anti-oncological properties of spiro-alkaloids. The dispiro[2H-indene-2,3'-pyrrolidine-2',3''-[3H]indole]-1,2''(1''H, 3H)-diones 20-38 were prepared via 1,3-dipolar cycloaddition reactions of azomethine ylides (generated in situ via decarboxylative condensation of isatins 7-9 with sarcosine 10) and 2-(arylmethylidene)-2,3-dihydro-1H-inden-1-ones 11-19 in refluxing ethanol. Some of the spiro-alkaloids (21, 22, 29 and 37) revealed potent antitumor properties against melanoma carcinoma cell lines (GaLa, LuPiCi and LuCa) utilizing the in vitro SRB standard method exhibiting potency close to that of the standard reference doxorubicin.

Microwave assisted synthesis and QSAR study of novel NSAID acetaminophen conjugates with amino acid linkers.

Novel, non-steroidal anti-inflammatory drug (NSAID), acetaminophen conjugates 6a­l with amino acid linkers were synthesized utilizing benzotriazole chemistry. Biological data acquired for all the novel bis-conjugates showed (a) some bis-conjugates (6d, 6e, 6h, and 6k) exhibit more potent anti-inflammatory activity than their parent drugs, (b) the potent bis-conjugates show no visible stomach lesions in contrast to parent drugs which are highly ulcerogenic, and (c) that the potent bio-active compounds have no mortality rates or toxic symptoms at 5 fold the applied anti-inflammatory dosage. A statistically significant QSAR model describing the anti-inflammatory properties of 6a­l (N = 15, n = 3, R(2) = 0.891, R(2)cvOO = 0.770, R(2)cvMO = 0.796, F = 29.904, s(2) = 0.011) was obtained employing CODESSA-Pro that validated the observed bio-activity.

Synthesis, bioassay, and molecular field topology analysis of diverse vasodilatory heterocycles.

A diverse training set composed of 76 in-house synthesized and 61 collected from the literature was subjected to molecular field topology analysis. This resulted in a high-quality quantitative structure-activity relationships model (R² = 0.932, Q² = 0.809) which was used for the topological functional core identification and prediction of vasodilatory activity of 19 novel pyridinecarbonitriles, which turned out to be active in experimental bioassay.

Design and Synthesis of Aspirin-chalcone Mimic Conjugates as Potential Anticancer Agents.

BACKGROUND: Extensive research has been conducted on aspirin, a widely recognized NSAID medication, regarding its potential as an anticancer agent. Studies have revealed its ability to trigger cell death in different types of cancer cells. METHODS: A set of aspirin-chalcone mimic conjugates 5a-k and 6a-d utilizing the freshly prepared acid chloride of aspirin moiety has been designed and synthesized. To evaluate the newly developed compounds, the NCI 60- cell line panel was employed to assess their anti-proliferative properties. Subsequently, cell cycle analysis was conducted along with an examination of the compounds' impact on the levels of p53, Bax, Bcl-2, active caspase- 3, and their inhibition mechanism of tubulin polymerization. RESULTS: Derivative 6c displayed the best anticancer activity among the tested series while 6d was the best against breast cancer MDA-MB-468, therefore both of them were selected for the 5-dose stage, however, targeting MDA-MB-468, PI-flow cytometry of compound 6d proved the triggered cell growth arrest at the G1/S phase avoiding the mitotic cycle in MDA-MB-468 cells. Similarly, the upregulation of oncogenic parameters such as caspase-3, p53, and Bax/Bcl-2, along with the inhibition of PARP-1 enzyme level, was observed with compound 6d. This compound also exhibited a significant ability to induce apoptosis and disrupt the intracellular microtubule network through a promising activity as a tubulin polymerization inhibitor with IC50 = 1.065 ± 0.024 ng/ml. Furthermore, to examine the manner in which compound 6d binds to the active pocket of the tubulin polymerization enzyme, a molecular docking study was conducted. CONCLUSION: The study indicated that compound 6d could be a powerful microtubule-destabilizing agent. Therefore, further research on 6d could be worthwhile.

Synthesis, crystal structure and in vitro anti-proliferative activity of 2-[(4-acetyl-phen-yl)carbamo-yl]phenyl acetate.

2-[(4-Acetyl-phen-yl)carbamo-yl]phenyl acetate, C17H15NO4, has been synthesized and structurally characterized. In the structure, N-H⋯O hydrogen-bonding inter-actions form chains of mol-ecules aligned along the [101] direction. The chains are linked by π-π and C-H⋯π inter-actions, forming a three dimensional network. The compound has been screened for in vitro anti-proliferative activity revealing considerable activity.

Hydrazone-sulfonate hybrids as potential cholinesterase inhibitors: design, synthesis and molecular modeling simulation.

Aim: Design and synthesis of a series of hydrazone-sulfonate hybrids, 5a-r. Methodology: The inhibitory properties of the synthesized compounds against acetylcholinesterase and butyrylcholinesterase were evaluated using donepezil as the reference standard. Results & conclusion: Compound 5e was identified as the most potent inhibitor of acetylcholinesterase (IC50 = 9.30 µM), and compound 5i was the most potent inhibitor of butyrylcholinesterase (IC50 = 11.82 µM). To confirm the safety of the most potent hits at the used doses, toxicological bioassays were conducted. Molecular docking was performed and the tested derivatives were found to fit well in the active sites of both enzymes. This study provides valuable insights into the potential of hydrazone-sulfonate hybrids as drug candidates.

Development of spiro-3-indolin-2-one containing compounds of antiproliferative and anti-SARS-CoV-2 properties.

A series of 1″-(alkylsulfonyl)-dispiro[indoline-3,2'-pyrrolidine-3',3″-piperidine]-2,4″-diones 6a‒o has been synthesized through regioselective multi-component azomethine dipolar cycloaddition reaction of 1-(alkylsulfonyl)-3,5-bis(ylidene)-piperidin-4-ones 3a‒h. X-ray diffraction studies (6b‒d,h) confirmed the structures. The majority of the synthesized analogs reveal promising antiproliferation properties against a variety of human cancer cell lines (MCF7, HCT116, A431 and PaCa2) with good selectivity index towards normal cell (RPE1). Some of the synthesized agents exhibit potent inhibitory properties against the tested cell lines with higher efficacies than the standard references (sunitinib and 5-fluorouracil). Compound 6m is the most potent. Multi-targeted inhibitory properties against EGFR and VEGFR-2 have been observed for the synthesized agents. Flow cytometry supports the antiproliferation properties and shows the tested agents as apoptosis and necrosis forming. Vero cell viral infection model demonstrates the anti-SARS-CoV-2 properties of the synthesized agents. Compound 6f is the most promising (about 3.3 and 4.8 times the potency of the standard references, chloroquine and hydroxychloroquine). QSAR models explain and support the observed biological properties.

Novel benzimidazole derivatives as expected anticancer agents.

A series of 1-(1H-benzimidazol-2-yl)-3-(substituted)-2-propen-1-one and its 1-methyl analogues 2c-h were synthesized and cyclized with different reagents such as ethyl cyanoacetate, thiourea, hydroxylamine hydrochloride, guanidinium sulfate, methylhydrazine, phenylhydrazine and/or hydrogen peroxide in different reactions to produce pyridones 3a,b, pyrimidinethione 4a,b, isoxazole 5a,b, aminopyrimidine 6a,b, pyrazoline 7i-k and epoxy derivative 8, respectively. Acetohydrazide 10 reacted with formic acid, acetic anhydride, carbon disulfide and/or thiosemicarbazide to yield compounds 11-19. Also compound 21a,b was condensed with different monosaccharides to yield the corresponding N-glycoside Schiff's bases derivatives 22a-h, which upon treatment with acetic anhydride afforded 23a-h derivatives. The anticancer activity of some of the newly synthesized compounds was evaluated against HEPG2 (human liver carcinoma cell line) and PC12 (pheochromocytoma of the rat adrenal medulla) cells. Benzimidazole-2-isoxazole 5a derivative exhibited high potency against HEPG2 and PC12 cells. Benzimidazole chalcones 2c,e, benzimidazole mercaptoacetohydrazide 14 and benzimidazole thiosemicarbazide 15a,b derivatives gave high potency against PC12 cells.

New pyridine and chromene scaffolds as potent vasorelaxant and anticancer agents.

Based on studies that have reported the association between cancer and cardiovascular diseases, new series of pyridine- (3a-o) and/or chromene- (4a-e) carbonitrile analogous were designed, synthesized and screened for their vasodilation and cytotoxic properties. The majority of the new chemical entities demonstrated significant vasodilation efficacies, compounds 3a, 3h, 3j, 3m, 3o, 4d and 4e exhibited the most promising potency with IC50 = 437.9, 481.0, 484.5, 444.8, 312.1, 427.6 and 417.2 µM, respectively, exceeding prazosin hydrochloride (IC50 = 487.3 µM). Compounds 3b-e, 3k and 3l also, revealed moderate vasodilation activity with IC50 values ranging from 489.7 to 584.5 µM. In addition, the anti-proliferative activity evaluation of the experimental compounds at 10 µM on the MCF-7 and MDA-MB 231 breast cancer cell lines illustrated the excellent anti-proliferative properties of derivatives 3d, 3g and 3i. Compound 3d was the most potent analogue with IC50 = 4.55 ± 0.88 and 9.87 ± 0.89 µM against MCF-7 and MDA-MB 231, respectively. Moreover, compound 3d stimulated apoptosis and cell cycle arrest at the S phase in MCF-7 cells in addition to its capability in accumulation of cells in pre-G1 phase and activating caspase-3. Furthermore, the molecular docking of 3d was performed to discover the binding modes within the active site of caspase-3. 3d, as the only common bi-functional agent among the tested hits, demonstrated that new pyridine-3-carbonitrile derivatives bearing cycloheptyl ring systems offer potential as new therapeutic candidates with combined vasodilation and anticancer properties.

Synthesis and Cytotoxic Properties of New Substituted Glycosides-Indole Conjugates as Apoptosis Inducers in Cancer Cells.

BACKGROUND & OBJECTIVE: Glycosyl heterocycles, being as nucleoside analogs with modified glycon and hybrid heterocycle motifs, are of considerable interest, and thus, the targeted compounds were synthesized via a convenient and efficient approach. METHODS: New indolyl-thiadiazolyl thioglycosides scaffolds were synthesized, starting with the reaction of indole-3-carbaldehyde with 2-aminothiadiazole-5-thiole followed by glycosylation and deprotection. Likewise, new molecular hybrids comprising indole, thiadiazole, triazole and glycosyl moieties were synthesized utilizing click chemistry strategy. The cytotoxic activities of the newly synthesized compounds were studied on colon carcinoma HCT116, breast carcinoma MCF-7, lung carcinoma A549 and hepatocellular carcinoma HepG2 cell lines using Sulphorhodamine-B (SRB) assay. RESULTS: The 1,3,4-thiadiazole thioglycoside and the 1,2,3-triazole N1-glycoside possessing xylose moiety, compounds 8 and 15 revealed the most potent bio-activity among the new chemical entities; therefore, they undertook for further analysis of apoptosis. CONCLUSION: IC50s of Compound 8 were 38, 36, 33 and 158µg/ml, while they were 41, 44, 32 and 25µg/ml for compound 15 on HepG2, MCF7, HCT116 and A549 cell lines, respectively; furthermore, the total apoptosis rate (%) for control untreated cells were 9.63, 28.4, 25.4 (%), compounds 8 and 15 respectively, they produced a significant increase in total and early apoptosis rate (%) compared to control (P=0.0001). At the same time, no significant difference was detected in the late apoptosis rate (%), which means that both derivatives have the potential to be developed into potent anticancer agents.

Synthesis of new ibuprofen hybrid conjugates as potential anti-inflammatory and analgesic agents.

Background: A new set of hybrid conjugates derived from 2-(4-isobutylphenyl)propanoic acid (ibuprofen) is synthesized to overcome the drawbacks of the current non-steroidal anti-inflammatory drugs. Results & methodology: Synthesized conjugates were screened for their anti-inflammatory, analgesic and ulcerogenic properties. Few conjugates were found to have significant anti-inflammatory properties in the carrageenan-induced rat paw edema test, while a fair number of conjugates showed promising peripheral analgesic activity in the acetic acid-induced writhing test as well as central analgesic properties in the in vivo hot plate technique. The newly synthesized conjugates did not display any ulcerogenic liability. Conclusion:In vitro, COX-1 and COX-2 enzyme inhibition studies raveled compound 7e is more selective toward COX-2 compared with ibuprofen.

Antiviral and antischistosomal evaluation of newly synthesized thioglycosides and their acyclic analogues.

The pyrimidine thione derivatives 2a-d were prepared by the reaction of thiourea, ethyl cyanoacetate and several aromatic aldehydes. The acyclic thioglycosides 4a-7d were prepared by the reaction of the synthesized pyrimidine thiones 2a-d with different alkyl halides, whereas the reaction of 2a-d with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide afforded the cyclic thioglycosides 8a-d whose deprotection afforded 9a-d. The obtained compounds were tested for their antischistosomal and antiviral activity against hepatitis B virus (HBV). Compounds 5a, 5d, 7a showed high activity against HBV using the MTT assay; moreover compounds 5c, 6d, 7a, 9a, 9c exhibited high activity as antischistosomal agents.