Showing papers in "Archiv Der Pharmazie in 2017"
TL;DR: The current development of benzimidazole‐based anticancer agents along with the synthetic approaches and structure–activity relationships (SAR) are covered.
Abstract: Cancer, also known as malignant neoplasm, is a dreadful disease which involves abnormal cell growth having the potential to invade or spread to other parts of the body Benzimidazole is an organic compound that is heterocyclic and aromatic in nature It is a bicyclic compound formed by the fusion of the benzene and imidazole ring systems It is an important pharmacophore and a privileged structure in medicinal chemistry According to the World Health Organisation (2015 survey), one in six deaths is due to cancer around the globe, accounting for 88 million deaths of which 70% of the cases were from low- and middle-income countries In the efforts to develop suitable anticancer drugs, medicinal chemists have focussed on benzimidazole derivatives This review article covers the current development of benzimidazole-based anticancer agents along with the synthetic approaches and structure-activity relationships (SAR)
90 citations
TL;DR: Three series of imidazolidinium ligands substituted with 4‐vinylbenzyl, 2‐methyl‐1,4‐benzodioxane, and N‐propylphthalimide were synthesized and the inhibitory effects of the novel synthesized NHCs were compared to acetazolamide as a clinical CA isoenzymes inhibitor and tacrine as aclinical cholinergic enzymes inhibitor.
Abstract: Three series of imidazolidinium ligands (NHC precursors) substituted with 4-vinylbenzyl, 2-methyl-1,4-benzodioxane, and N-propylphthalimide were synthesized. N-Heterocyclic carbene (NHC) precursors were prepared from N-alkylimidazoline and alkyl halides. The novel NHC precursors were characterized by 1H NMR, 13C NMR, FTIR spectroscopy, and elemental analysis techniques. The enzymes inhibition activities of the NHC precursors were investigated against the cytosolic human carbonic anhydrase I and II isoenzymes (hCA I and II) and the acetylcholinesterase (AChE) enzyme. The inhibition parameters (IC50 and Ki values) were calculated by spectrophotometric method. The inhibition constants (Ki) were found to be in the range of 166.65–635.38 nM for hCA I, 78.79–246.17 nM for hCA II, and 23.42–62.04 nM for AChE. Also, the inhibitory effects of the novel synthesized NHCs were compared to acetazolamide as a clinical CA isoenzymes inhibitor and tacrine as a clinical cholinergic enzymes inhibitor.
75 citations
TL;DR: Novel series of phthalazine derivatives 6–11 were designed, synthesized, and evaluated for their anticancer activity against two human tumor cell lines, HCT‐116 human colon adenocarcinoma and MCF‐7 breast cancer cells, targeting the VEGFR‐2 enzyme.
Abstract: Novel series of phthalazine derivatives 6-11 were designed, synthesized, and evaluated for their anticancer activity against two human tumor cell lines, HCT-116 human colon adenocarcinoma and MCF-7 breast cancer cells, targeting the VEGFR-2 enzyme. Compounds 7a,b and 8b,c showed the highest anticancer activities against both HCT116 human colon adenocarcinoma cells with IC50 of 6.04 ± 0.30, 13.22 ± 0.22, 18 ± 0.20, and 35 ± 0.45 μM, respectively, and MCF-7 breast cancer cells with IC50 of 8.8 ± 0.45, 17.9 ± 0.50, 25.2 ± 0.55, and 44.3 ± 0.49 μM, respectively, in comparison to sorafenib as reference drug with IC50 of 5.47 ± 0.3 and 7.26 ± 0.3 μM, respectively. Eleven compounds in this series were further evaluated for their inhibitory activity against VEGFR-2, where compounds 7a, 7b, 8c, and 8b also showed the highest VEGFR-2 inhibition with IC50 of 0.11 ± 0.01, 0.31 ± 0.03, 0.72 ± 0.08, and 0.91 ± 0.08 μM, respectively, in comparison to sorafenib as reference ligand with IC50 of 0.1 ± 0.02. Furthermore, molecular docking studies were performed for all synthesized compounds to predict their binding pattern and affinity towards the VEGFR-2 active site, in order to rationalize their anticancer activity in a qualitative way.
48 citations
TL;DR: The findings suggest that the new compounds 2a–i have superior inhibitory effect over acetazolamide (AZA), which is used as clinical CA inhibitor, with obtained Ki values of 34.50 and 28.93 nM against the hCA I and II isozymes, respectively.
Abstract: In the present study, human carbonic anhydrase (hCA) enzyme was purified and characterized from fresh blood human red cells by Sepharose-4B-l-tyrosine-sulfanilamide affinity gel chromatography. Secondly, a series of new tetrabromo chalcone derivatives containing 4,7-methanoisoindol-1,3-dione (2a–i) were synthesized from the addition of Br2 to related chalcone derivatives (1a–i). The structures of the new molecules (2a–i) were confirmed by means of 1H NMR, 13C NMR and elemental analysis. Finally, the inhibitory effects of 2a–i on CA activities were investigated using the esterase method under in vitro conditions. The compounds 2a–i exhibited excellent inhibitory effects, in the low nanomolar range, with Ki values in the range of 11.30–21.22 nM against hCA I and in the range of 8.21–12.86 nM against hCA II. Our findings suggest that the new compounds 2a–i have superior inhibitory effect over acetazolamide (AZA), which is used as clinical CA inhibitor, with obtained Ki values of 34.50 and 28.93 nM against the hCA I and II isozymes, respectively. In addition to the inhibition assays, molecular modeling approaches were implemented for prediction of the binding affinities of compounds 2a and 2c, which had the highest inhibition effects, against the hCA I and II isozymes.
39 citations
TL;DR: The bipyrazole 10 and the pyranopyrazole 27 could be considered as the most active members in this study, being nearly equiactive to celecoxib, besides their obvious selective COX‐2 inhibition, high safety margin, and predicted pharmacokinetic (ADME‐T) suitability for oral use.
Abstract: The synthesis and evaluation of the anti-inflammatory activity of some structure hybrids comprising basically the 5-hydroxy-3-methyl-1-phenyl-4-substituted-1H-pyrazole scaffold directly linked to a variety of heterocycles and functionalities, or annulated as pyrano[2,3-c]pyrazoles, is described. According to the in vivo results and a comprehensive structure-activity relationship study, five analogs (5, 10, 17, 19, and 27) displayed remarkable anti-inflammatory profiles showing distinctive % protection and ED50 values, especially 10 and 27 (ED50 35.7 and 38.7 μmol/kg, respectively) which were nearly equiactive to celecoxib (ED50 32.1 μmol/kg). Compounds 10, 17, and 27 exhibited distinctive COX-2 inhibition with a noticeable COX-2 selectivity (SI values 7.83, 6.87, and 7.16, respectively), close to that of celecoxib (SI 8.68). Additionally, 5, 10, 17, 19, and 27 proved to be gastrointestinal tract safe (0-20% ulceration) and non-toxic, being well tolerated by the experimental animals up to 250 mg/kg orally and 80 mg/kg parenterally. Collectively, the in vivo ED50 values for the most potent five derivatives agree with their in vitro COX-2 selectivity indices, suggesting their usefulness as selective anti-inflammatory COX-2 inhibitors. The bipyrazole 10 and the pyranopyrazole 27 could be considered as the most active members in this study, being nearly equiactive to celecoxib, besides their obvious selective COX-2 inhibition, high safety margin, and predicted pharmacokinetic (ADME-T) suitability for oral use.
38 citations
TL;DR: Two series of benzodioxole–pyrazole hybrids were synthesized and the IC50 values for in vitro inhibition of the enzymes cyclooxygenase 1/2 (COX‐1, COX‐2) and 5‐lipoxygenases (5‐LOX) were investigated, and compounds 11, 17, and 26 displayed significant anti‐inflammatory, analgesic, and antioxidant activities, beside dual COX-2 and 5-LOX inhibition.
Abstract: Two series of benzodioxole-pyrazole hybrids were synthesized and the IC50 values for in vitro inhibition of the enzymes cyclooxygenase 1/2 (COX-1, COX-2) and 5-lipoxygenase (5-LOX) were investigated. All compounds were tested for their in vivo anti-inflammatory and analgesic potentials using diclofenac sodium as a reference standard. Compounds 4, 11, 17, 20, 21, 26, and 27, which showed good analgesic and/or anti-inflammatory activities, were also evaluated for their ability to inhibit tumor necrosis factor (TNF)-α production, myeloperoxidase and proteinase, beside their antioxidant activity. Collectively, compounds 11, 17, and 26 displayed significant anti-inflammatory, analgesic, and antioxidant activities, beside dual COX-2 and 5-LOX inhibition. Among these, compound 26 showed high selectivity for in vitro COX-1/COX-2 inhibition, whereas the analogs 11 and 17 noticeably ameliorated the TNF-α level by 85.19 and 97.71%, respectively. A molecular docking study was performed to investigate the possible binding mode of compounds 11, 17, and 26 with the active sites of the COX-2 and 5-LOX enzymes, where they showed nearly the same binding pattern as that of celecoxib and meclofenamic acid, respectively.
37 citations
TL;DR: Docking experiments carried out on VEGFR‐2 and p38 MAPK crystallographic structures revealed that the active compounds bind to the active sites through H‐bonds, arene–cation, and hydrophobic π–π interactions, indicating the reliability of the established QSAR model.
Abstract: Breast and cervical cancers are the most common gender-specific cancers affecting women worldwide. In this investigation, we highlighted the synthesis, VEGFR-2 and p38α MAPK inhibitory activity of new series of fluorinated coumarin-based derivatives featuring a variety of bioactive chemical moieties attached or fused to the coumarin nucleus at the 3 and/or 4 position. The bioactive inhibitors were further assessed for their anti-proliferative effect against human MCF-7 breast cancer and HeLa cervical cancer cell lines, respectively. Most of the tested compounds showed potent preferential inhibition effects against human VEGFR-2 and remarkable anticancer activities in the human breast cancer cell line MCF-7. Compounds 29, 24, and 2 displayed the highest inhibitory activity against VEGFR-2 (94% inhibition) and they were the most potent anticancer agents toward MCF-7 cancer cells with IC50 values of 7.90, 8.28, and 8.30 μg/mL, respectively. Compound 13 inhibited p38α MAPK phosphorylation with a significant reduction in % cell viability against HeLa cancer cells at 10 and 30 µM. Docking experiments carried out on VEGFR-2 and p38 MAPK crystallographic structures revealed that the active compounds bind to the active sites through H-bonds, arene–cation, and hydrophobic π–π interactions. QSAR analysis demonstrated considerable correlation coefficient (R2 = 0.76969) and root mean square error (RMSE = 0.10446) values. Also, the residual values between the experimental pIC50 and predicted pIC50 are very close, indicating the reliability of the established QSAR model.
33 citations
TL;DR: It was shown that triazolo[1,5‐a]pyrimidine‐7(4H)‐ones exhibit a higher antiglycation activity than the corresponding 7‐alkylamino analogs and aminoguanidine, as the reference compound, and it is suggested that this kind of activity can be associated with the chelating properties possessed by the synthesized 6‐nitro‐7‐oxoderivatives.
Abstract: Prevention of the formation of advanced glycation end-products (AGEs) is a reliable approach to achieve control over hyperglycemia and the associated pathogenesis of diabetic vascular complications. In these terms, new synthetic approaches to 6-nitroazolo[1,5-a]pyrimidines have been developed on the basis of the promising antiglycation activity of their structural analogues, such as azolo[5,1-c][1,2,4]triazine-4(1H)-ones. A number of nitroazolopyrimidines were obtained by using nitration, chlorodeoxygenation, and amination reactions, and their antidiabetic properties were elucidated in vitro. It was shown that triazolo[1,5-a]pyrimidine-7(4H)-ones exhibit a higher antiglycation activity than the corresponding 7-alkylamino analogs and aminoguanidine, as the reference compound. It is suggested that this kind of activity can be associated with the chelating properties possessed by the synthesized 6-nitro-7-oxoderivatives. Furthermore, the compounds obtained were tested for their inhibitory activity against dipeptidyl peptidase 4 (DPP4), glycogen phosphorylase, and α-glucosidase in vitro, but their activities proved to be significantly inferior to those of the reference compounds.
33 citations
TL;DR: Most of the newly synthesized hybrid molecules showed notable antitumor activities against the tested tumor cell lines, and compounds 8i and 8l showed the best anti‐lipase activity at a concentration of 10 μM.
Abstract: The design, synthesis, and investigation of antitumor and anti-lipase activities of some coumarin–triazole hybrid molecules are reported The synthesis of these hybrid molecules was performed under microwave irradiation and conventional heating procedures The newly synthesized hybrid molecules were investigated as inhibitors against four tumor cell lines (BT20 human breast carcinoma, SK-Mel 128 melanoma, DU-145 prostate carcinoma, and A549 lung carcinoma) and porcine pancreatic lipase (PPL) Most of these compounds showed notable antitumor activities against the tested tumor cell lines, and compounds 8i and 8l showed the best anti-lipase activity of 9930 ± 056% and 9985 ± 121%, respectively, at a concentration of 10 μM
31 citations
TL;DR: The findings suggest that the synthesized compound possessed prospective pain, inflammation, and pyrexia relieving propensities and therefore may serve as a potential drug candidate for the therapeutic management of chronic pain conditions.
Abstract: A novel pregabalin derivative named as pregsal ((S,E)-3-(((2-hydroxybenzylidene)amino)methyl)-5-methylhexanoic acid) was synthesized by a simple imination reaction between pregabalin and salicylaldehyde and was evaluated in the in vivo testing paradigms. The compound was characterized by UV, IR, 1H, 13C NMR, HR ESI-MS, and elemental analysis. It was screened (30, 50, 75, and 100 mg/kg) for antinociceptive, anti-inflammatory, and antipyretic activities in relation to pregabalin. The synthesized compound significantly attenuated the tonic acetic acid-induced nociceptive pain (30 mg/kg (P < 0.05), 50 mg/kg (P < 0.01), 75 and 100 mg/kg (P < 0.001)), and thermal-induced hyperalgesia (P < 0.001). These activities were succinctly antagonized (P < 0.05, P < 0.01, P < 0.001) by naloxone and pentylenetetrazole, implicating the involvement of opioidergic and GABAergic mechanisms. The compound also inhibited the temporal inflammatory response and alleviated the yeast-induced pyrexia (P < 0.05, P < 0.01, and P < 0.001). These findings suggest that the synthesized compound possessed prospective pain, inflammation, and pyrexia relieving propensities and therefore may serve as a potential drug candidate for the therapeutic management of chronic pain conditions.
24 citations
TL;DR: From the two considered classes of heterocyclic compounds, the pyrazolotriazines showed the highest potency as antiglycating agents and DPP4 inhibitors.
Abstract: Inhibition of the dipeptidyl peptidase-4 (DPP4) enzyme activity and prevention of advanced glycation end (AGE) products formation represents a reliable approach to achieve control over hyperglycemia and the associated pathogenesis of diabetic vascular complications. In the frames of this research study, several triazolo- and pyrazolotriazines were synthesized and evaluated as inhibitors of AGE products formation, DPP4, glycogen phosphorylase and α-glucosidase activities, as well as AGE cross-link breakers. From the two considered classes of heterocyclic compounds, the pyrazolotriazines showed the highest potency as antiglycating agents and DPP4 inhibitors. Structure-activity relationships (SAR) for these compounds, which can be considered as potential drugs for the treatment of type 2 diabetes, were evaluated.
TL;DR: A series of novel curcuminoids were synthesised for the first time via a Mannich‐3CR/organocatalysed Claisen–Schmidt condensation sequence for anti‐proliferative activity against A549 and H1975 lung adenocarcinoma cells and showed inhibition of tumour growth.
Abstract: A series of novel curcuminoids were synthesised for the first time via a Mannich-3CR/organocatalysed Claisen-Schmidt condensation sequence. Structure-activity relationship (SAR) studies were performed by applying viability assays and holographic microscopic imaging to these curcumin analogues for anti-proliferative activity against A549 and H1975 lung adenocarcinoma cells. The TNFα-induced NF-κB inhibition and autophagy induction effects correlated strongly with the cytotoxic potential of the analogues. Significant inhibition of tumour growth was observed when the most potent analogue 44 was added in liposomes at one-sixth of the maximally tolerated dose in the A549 xenograft model. The novel spectrum of activity of these Mannich curcuminoids warrants further preclinical investigations.
TL;DR: The antioxidant effects of the synthesized compounds against FeCl2/ascorbic acid‐induced oxidative stress in the rat brain in vitro showed that most of the compounds are effective as radical scavengers.
Abstract: A series of Mannich bases of benzimidazole derivatives having a phenolic group were designed to assess their anticholinesterase and antioxidant activities. The acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activities were evaluated in vitro by using Ellman's method. According to the activity results, all of the compounds exhibited moderate to good AChE inhibitory activity (except for 2a), with IC50 values ranging from 0.93 to 10.85 μM, and generally displayed moderate BuChE inhibitory activity. Also, most of the compounds were selective against BuChE. Compound 4b was the most active molecule on the AChE enzyme and also selective. In addition, we investigated the antioxidant effects of the synthesized compounds against FeCl2/ascorbic acid-induced oxidative stress in the rat brain in vitro, and the activity results showed that most of the compounds are effective as radical scavengers. Molecular docking studies and molecular dynamics simulations were also carried out.
TL;DR: A diverse series of 45 compounds with reported SIRT1 inhibitory activity has been employed for the development of quantitative structure–activity relationship (QSAR) models using the Monte Carlo optimization method.
Abstract: SIRT1 inhibitors offer therapeutic potential for the treatment of a number of diseases including cancer and human immunodeficiency virus infection. A diverse series of 45 compounds with reported SIRT1 inhibitory activity has been employed for the development of quantitative structure-activity relationship (QSAR) models using the Monte Carlo optimization method. This method makes use of simplified molecular input line entry system notation of the molecular structure. The QSAR models were built up according to OECD principles. Three subsets of three splits were examined and validated by respective external sets. All the three described models have good statistical quality. The best model has the following statistical characteristics: R2 = 0.8350, Q2test = 0.7491 for the test set and R2 = 0.9655, Q2ext = 0.9261 for the validation set. In the mechanistic interpretation, structural attributes responsible for the endpoint increase and decrease are defined. Further, the design of some prospective SIRT1 inhibitors is also presented on the basis of these structural attributes.
TL;DR: New series of diarylpyrazoles 8a–f and triarylimidazoline‐5‐ones 11a–g were synthesized and evaluated for their in vitro cyclooxygenase‐1 and COX‐2 inhibitory activity and in vivo anti‐inflammatory activity.
Abstract: New series of diarylpyrazoles 8a–f and triarylimidazoline-5-ones 11a–g were synthesized and evaluated for their in vitro cyclooxygenase-1 (COX-1) and COX-2 inhibitory activity and in vivo anti-inflammatory activity. The synthesized compounds showed good selectivity for COX-2; compounds 8a, 8d, 8f, 11a, and 11c exhibited the highest COX-2 selectivity indexes (SI = 4.77–5.43) compared to the reference drug celecoxib (SI = 7.8). All compounds showed good in vivo anti-inflammatory activity, especially compounds 8a, 8f, 11c, and 11d, which also showed some similarities to the time interval pattern of celecoxib at all different time intervals (1, 3, and 6 h).
TL;DR: All the 16 new quinazolinones exhibited good anticonvulsant activity; especially 5f, 5b, and 5c showed superior anticonVulsant activities in comparison to the reference drug, with ED50 values of 28.90, 47.38, and 56.40 mg/kg, respectively.
Abstract: Series of N-(4-substitutedphenyl)-4-(1-methyl (or 1,2-dimethyl)-4-oxo-1,2-dihydroquinazolin-3(4H)-yl)-alkanamides (5a-j) and 4-chloro-N'-((1-methyl (or 1,2-dimethyl)-4-oxo-1,2-dihydroquinazolin-3(4H)-yl)-alkaloyl)benzohydrazides (6a-f) were designed based on the previously reported essential structural features for anticonvulsant activity. Several amino acids were incorporated within the synthesized quinazolin-4(3H)-ones to improve their bioavailability and the anticonvulsant activity. Synthesis of the target compounds was accomplished in four steps starting from the reaction between N-methyl isatoic anhydride and the appropriate amino acid. Then, the carboxylic acid group was utilized to synthesize the required final structures. The new quinazolinone derivatives were evaluated for their anticonvulsant activity according to the Anticonvulsant Drug Development (ADD) Program protocol. All the 16 new quinazolinones exhibited good anticonvulsant activity; especially 5f, 5b, and 5c showed superior anticonvulsant activities in comparison to the reference drug, with ED50 values of 28.90, 47.38, and 56.40 mg/kg, respectively.
TL;DR: Among these tested compounds, 6j having a −CH3 group was found to be the most potent one against both enzymes (AChE, IC50’s= 3.73 ± 0.61 μM; BChE”=4.81±0.16M); Quantitative structure–activity relationship and molecular docking studies of the synthesized compounds were performed.
Abstract: A series of 13 novel pyrimidine-based sulfonamides 6a-m were synthesized in short periods of time under microwave conditions in good to excellent yield (54-86%). The chemical structures of these heterocycles consist of a central pyrimidine ring having a phenyl group and pyrimidine groups with sulfonamide motifs. The enzyme inhibitory potential of these compounds was investigated against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) because these enzymes play a crucial role in the treatment of Alzheimer's disease. As compared to the reference compound eserine (IC50 = 0.04 ± 0.0001 μM for AChE and IC50 = 0.85 ± 0.0001 μM for BChE), the IC50 values of the synthesized compounds ranged from 3.73 ± 0.61 μM to 57.36 ± 0.22 μM for AChE and 4.81 ± 0.16 μM to 111.61 ± 0.53 μM for BChE. Among these tested compounds, 6j having a -CH3 group was found to be the most potent one against both enzymes (AChE, IC50 = 3.73 ± 0.61 μM; BChE, IC50 = 4.81 ± 0.16 μM). Quantitative structure-activity relationship (QSAR) and molecular docking studies of the synthesized compounds were also performed.
TL;DR: A novel group of 5‐(3, 4‐dichlorophenyl)‐1,3,4‐oxadiazole‐2(3H)‐one Mannich bases were synthesized and characterized on the basis of IR, 1H NMR, and elemental analysis results to obtain an anti‐inflammatory agent devoid of GI side effects.
Abstract: Non-steroidal anti-inflammatory drugs (NSAIDs), which are widely used for the treatment of rheumatic arthritis, pain, and many different types of inflammatory disorders, cause serious gastrointestinal (GI) side effects. The free carboxylic acid group existing on their chemical structure is correlated with GI toxicity related with all routine NSAIDs. Replacing this functional group with the 1,3,4-oxadiazole bioisostere is a generally used strategy to obtain an anti-inflammatory agent devoid of GI side effects. In the present work, a novel group of 5-(3,4-dichlorophenyl)-1,3,4-oxadiazole-2(3H)-one Mannich bases were synthesized and characterized on the basis of IR, 1H NMR, and elemental analysis results. The target compounds were first tested for cytotoxicity to determine a non-toxic concentration for anti-inflammatory screening. Anti-inflammatory effects of the compounds were evaluated by in vitro lipopolysaccharide (LPS)-induced NO production and in vivo carrageenan footpad edema with ulcerogenic profile. In LPS-induced RAW 264.7 macrophages, most of the compounds showed inhibitory activity on nitrite production while compounds 5a, 5h, and 5j exhibited the best profiles by suppressing the NO production. To evaluate the in vivo anti-inflammatory potency of the compounds, the inflammatory response was quantified by increment in paw size in the carrageenan footpad edema assay. The anti-inflammatory data scoring showed that compounds 5a–d, 5g, and 5j, at the dose of 100 mg/kg, exhibited anti-inflammatory activity, which for compound 5g was comparable to that of the reference drug indomethacin with 53.9% and 55.5% inhibition in 60 and 120 min, respectively.
TL;DR: It is suggested that 4o and 4s may serve as leads in the discovery and development of new anticonvulsant drugs.
Abstract: A series of new pyrimidine-triazine hybrids (4a-t) was designed and synthesized, from which potent anticonvulsant agents were identified. Most of the compounds exhibited promising anticonvulsant activity against the maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) tests, along with minimal motor impairment with higher safety compared to the standard drugs, phenytoin and carbamazepine. In the series, 5-(4-(4-fluorophenyl)-6-(4-hydroxyphenyl)-2-thioxo-5,6-dihydropyrimidin-1(2H)-yl)-1,2-dihydro-1,2,4-triazin-3(6H)-one (4o) and 5-(6-(4-hydroxy-3-methoxyphenyl)-4-(4-hydroxyphenyl)-2-thioxo-5,6-dihydropyrimidin-1(2H)-yl)-1,2-dihydro-1,2,4-triazin-3(6H)-one (4s) emerged as most potent anticonvulsant agents with median doses of 22.54 and 29.40 mg/kg (MES ED50 ), 285.02 and 293.42 mg/kg (scPTZ ED50 ), and 389.11 and 412.16 mg/kg (TD50 ), respectively. Docking studies were also performed for all synthesized compounds to get insight into the binding pattern toward the GABAA receptor as a possible mechanism of their anticonvulsant action, and in silico ADME studies were carried out to predict the safety and stability of the molecules. The increased GABA level in the experimental animals in the neurochemical estimation assay confirmed their GABAergic modulating activity. The most potent compounds were also evaluated for their neurotoxic and hepatotoxic effects. Fortunately, they did not show any sign of neurotoxicity or hepatotoxicity, suggesting that they have a broad spectrum of anticonvulsant activity with a large safety margin. Together, this research suggested that 4o and 4s may serve as leads in the discovery and development of new anticonvulsant drugs.
TL;DR: III‐4 is a potent, selective, and durable inhibitor of JAK3 and has the potential for the treatment of inflammatory disorders and autoimmune diseases, such as rheumatoid arthritis.
Abstract: Selective inhibition of Janus kinase 3 (JAK3) has been identified as an important strategy for the treatment of autoimmune disorders. Based on the unique cysteine 909 residue (Cys909) of JAK3 at the gatekeeper position, we have developed a new irreversible covalent inhibitor, III-4, which is highly potent and selective in targeting JAK3. Importantly, III-4 selectively inhibited JAK3 (IC50 = 57 ± 1.21 nM) over other JAKs (IC50 > 10 µM) and Cys909 kinome members (IC50 > 1 µM). A cellular selectivity study also confirmed that III-4 preferentially inhibited JAK3 over JAK1 in JAK/STAT signaling. Moreover, the fact that III-4 covalently modified the Cys909 residue in JAK3 was clearly validated by mass spectrometry and covalent docking analysis. Based on the favorable target profiles, the pharmacokinetic properties and its low toxicity, III-4 exhibited better efficacy than tofacitinib in impeding disease progression in CIA mice, without any significant adverse effects. Taken together, III-4 is a potent, selective, and durable inhibitor of JAK3 and has the potential for the treatment of inflammatory disorders and autoimmune diseases, such as rheumatoid arthritis.
TL;DR: The long‐distance run leading to the marketed drug topotecan was developed from this lead structure by semi‐synthesis utilizing a Mannich aminomethylation as the crucial step, and further perspectives are summarized.
Abstract: Natural products are a rich source of bioactive compounds, and numerous natural compounds have found application in cancer chemotherapy. However, unfavorable physicochemical properties often prevent the use of the original natural product as a drug. A prominent example is camptothecin from the Chinese tree Camptotheca acuminata, which shows extraordinary cytotoxic activity based on a specific molecular mode of action (inhibition of human topoisomerase I). Due to its extremely poor solubility, the original natural product cannot be used as a drug. The marketed drug topotecan was developed from this lead structure by semi-synthesis utilizing a Mannich aminomethylation as the crucial step. In this review, the long-distance run leading to this drug and further perspectives are summarized.
TL;DR: This review focuses on the chemistry of thienopyrimidine derivatives, their potential activities against various kinases, and their structure–activity relationship studies.
Abstract: Thienopyrimidines (TP), comprising a thiophene ring fused with pyrimidine, are famous bioisosteres to purines, an essential part of the human metabolome. This scaffold has become an interesting structural element in the development of pharmaceutical compounds, due to their wide spectrum applications as cytotoxic agents against different types of human cancer cell lines, cGMP phosphodiesterase inhibitors, and anti-viral, anti-inflammatory, and anti-microbial agents. The structural similarity of this scaffold with adenine made it an excellent moiety to be used in the design of kinase inhibitors. This review focuses on the chemistry of thienopyrimidine derivatives, their potential activities against various kinases, and their structure-activity relationship studies.
TL;DR: New N‐[1‐(4‐chlorophenyl)‐2‐(1H‐imidazol‐1‐yl)ethylidene]hydroxylamine esters showing anticonvulsant activity in animal models, including the 6‐Hz psychomotor seizure test, a model for therapy‐resistant partial seizure.
Abstract: (Arylalkyl)azoles are a class of antiepileptic compounds including nafimidone, denzimol, and loreclezole (LRZ). Nafimidone and denzimol are thought to inhibit voltage-gated sodium channels (VGSCs) and enhance γ-aminobutyric acid (GABA)-mediated response. LRZ, a positive allosteric modulator of A-type GABA receptors (GABAA Rs), was reported to be sensitive to Asn265 of the β2/β3 subunit. Here, we report new N-[1-(4-chlorophenyl)-2-(1H-imidazol-1-yl)ethylidene]hydroxylamine esters showing anticonvulsant activity in animal models, including the 6-Hz psychomotor seizure test, a model for therapy-resistant partial seizure. We performed molecular docking studies for our active compounds using GABAA R and VGSC homology models. They predicted high affinity to the benzodiazepine binding site of GABAA R in line with the experimental results. Also, the binding mode and interactions of LRZ in its putative allosteric binding site of GABAA R is elucidated.
TL;DR: The findings indicate that arylsulfonylhydrazones may be a promising scaffold for the design of new drug candidates for the treatment of AD.
Abstract: Alzheimer's disease (AD) is the most common type of dementia and related to the degeneration of hippocampal cholinergic neurons, which dramatically affects cognitive ability. Acetylcholinesterase (AChE) inhibitors are employed as drugs for AD therapy. Three series of sulfonylhydrazone compounds were designed, and their ability to inhibit AChE was evaluated. Fifteen compounds were synthesized and twelve of them had IC50 values of 0.64–51.09 μM. The preliminary structure–activity relationships indicated that the methylcatechol moiety and arylsulfonyl substituents generated better compounds than both the benzodioxole and alkylsulfonyl chains. Molecular dynamics studies of compound 6d showed that the interaction with the peripheral binding site of AChE was similar to donepezil, which may explain its low IC50 (0.64 μM). Furthermore, the drug-likeness of 6d suggests that the compound may have appropriate oral absorption and brain penetration. Compound 6d also presented antiradical activity and was not cytotoxic to LL24 cells, suggesting that this compound might be considered safe. Our findings indicate that arylsulfonylhydrazones may be a promising scaffold for the design of new drug candidates for the treatment of AD.
TL;DR: The aim of this work was to identify anchor points for the introduction of sp3‐rich fragments with polar functional groups into the newly discovered active but nonpolar scaffold 1,2‐dihydro‐3H‐naphth[1, 2‐e][1,3]oxazine‐3‐thione by a molecular modeling approach and discover new SIRT2 inhibitors with improved aqueous solubility.
Abstract: Nonpolar derivatives of heterocyclic aromatic screening hits like the non-selective sirtuin inhibitor splitomicin tend to be poorly soluble in biological fluids Unlike sp3-rich natural products, flat aromatic compounds are prone to stacking and often difficult to optimize into leads with activity in cellular systems The aim of this work was to identify anchor points for the introduction of sp3-rich fragments with polar functional groups into the newly discovered active (IC50 = 5 μM) but nonpolar scaffold 1,2-dihydro-3H-naphth[1,2-e][1,3]oxazine-3-thione by a molecular modeling approach Docking studies were conducted with structural data from crystallized human SIRT2 enzyme Subsequent evaluation of the in silico hypotheses through synthesis and biological evaluation of the designed structures was accomplished with the aim to discover new SIRT2 inhibitors with improved aqueous solubility Derivatives of 8-bromo-1,2-dihydro-3H-naphth[1,2-e][1,3]oxazine-3-thione N-alkylated with a hydrophilic morpholino-alkyl chain at the thiocarbamate group intended for binding in the acetyl-lysine pocket of the enzyme appeared to be promising Both the sulfur of the thiocarbamate and the bromo substituent were assumed to result in favorable hydrophobic interactions and the basic morpholino-nitrogen was predicted to build a hydrogen bond with the backbone Ile196 While the brominated scaffold showed moderately improved activity (IC50 = 18 μM), none of the new compounds displayed submicromolar activity Synthesis and characterization of the new compounds are reported and the possible reasons for the outcome are discussed
TL;DR: In vitro studies of a different series of substituted 2‐benzamido‐4‐methylthiazole‐5‐carboxylic acid derivatives revealed that the presence of a fluoro group at the para position in 5b and a chloro group in 5c signifies excellent XO inhibitory activity among the series, along with their DPPH free radial scavenging activity.
Abstract: The new chemical entities febuxostat and topiroxostat have been approved by the US Food and Drug Administration, opening new avenues for exploiting different heterocycles other than purines as xanthine oxidase (XO) inhibitors. A different series of substituted 2-benzamido-4-methylthiazole-5-carboxylic acid derivatives (5a–r) was synthesized and characterized by the collective use of IR, 1H and 13C NMR, and mass spectroscopy, for the treatment of gout and hyperuricemia. In vitro studies of the synthesized derivatives revealed that the presence of a fluoro group at the para position in 5b (IC50 = 0.57 μm) and a chloro group in 5c (IC50 = 0.91 μm) signifies excellent XO inhibitory activity among the series, along with their DPPH free radial scavenging activity. In vivo serum uric acid inhibition studies established that 5b and 5c displayed 62 and 53% uric acid inhibition, respectively. Studies on enzyme kinetics indicated that 5b acts as a mixed type inhibitor. In silico prediction by various softwares also helped in the recognition of potent XO inhibitors.
TL;DR: Compound 12 exhibited a selective killing ability on Mcl‐1‐dependent cancer cells and provided evidence that additional occupation of the p1 pocket is more favorable for MCl‐1 than for Bcl‐2 binding, and contributes more to M cl‐1 inhibition than occupation ofThe p2 pocket.
Abstract: Based on a known selective Mcl-1 inhibitor, 6-chloro-3-(3-(4-chloro-3,5-dimethylphenoxy)propyl)-1H-indole-2-carboxylic acid, we applied a fragment-based approach to obtain new molecules that extended into the p1 pocket of the BH3 groove and then exhibited binding selectivity for the Mcl-1 over the Bcl-2 protein. After we deconstructed the 1H-indole-2-carboxylic acid from the parental molecule, a benzenesulfonyl was substituted at the 1-position to adopt a geometry preferred for accessing the p1 pocket according to the binding mode of the parental molecule identified by X-ray crystallography. A linear relationship between the free energy of ligand binding (ΔG) and the count of non-hydrogen heavy atoms (HAC) was maintained during the molecular growing to occupy the p1 pocket. Finally, we not only obtained compound 12 with a 7.5-fold selectivity to Mcl-1 (Ki = 0.48 µM by fluorescence polarization) over Bcl-2 (Ki = 3.6 µM), but also provided evidence that additional occupation of the p1 pocket is more favorable for Mcl-1 than for Bcl-2 binding, and contributes more to Mcl-1 inhibition than occupation of the p2 pocket. Compound 12 exhibited a selective killing ability on Mcl-1-dependent cancer cells.
TL;DR: A novel series of quinazoline clubbed thiazoline derivatives was rationally designed and synthesized and exhibited the most promising results, with docking of compound 4x into the active site of DPP‐4 illustrating its possible binding interactions.
Abstract: A novel series of quinazoline clubbed thiazoline derivatives was rationally designed and synthesized. The newly synthesized compounds were evaluated for in vitro dipeptidyl peptidase IV (DPP-4) inhibitory activity. Compounds that showed good to moderate activity were compared using linagliptin as standard. Compound 4x (IC50 = 1.12 nM) exhibited the most promising results. The special chemical feature of compound 4x also imparts good inhibition selectivity for DPP-4 over DPP-8/9. Moreover, docking of compound 4x into the active site of DPP-4 illustrates its possible binding interactions.
TL;DR: Two novel 2,6‐disubstituted pyridazine‐3(2H)‐one derivatives demonstrated the most potent and consistent anti‐inflammatory activity over the synthesized compounds, which was significantly higher than that of celecoxib in the carrageenin rat paw edema model and with milder ulcer scoring than that in the ulcerogenicity screening.
Abstract: Some novel 2,6-disubstituted pyridazine-3(2H)-one derivatives were synthesized and evaluated for in vitro cyclooxygenase-2 (COX-2) inhibitory efficacy. Compounds 2-{[3-(2-methylphenoxy)-6-oxopyridazin-1(6H)-yl]methyl}-1H-isoindole-1,3(2H)-dione (5a), 2-propyl-6-(o-tolyloxy)pyridazin-3(2H)-one (6a), and 2-benzyl-6-(3,5-dimethyl-1H-pyrazol-1-yl)pyridazin-3(2H)-one (16a) showed the most potent COX-2 inhibitory activity with IC50 values of 0.19, 0.11, and 0.24 μM, respectively. The synthesized compounds with the highest COX-2 selectivity indices were evaluated for their anti-inflammatory, analgesic, and ulcerogenic activities. Compounds 6a and 16a demonstrated the most potent and consistent anti-inflammatory activity over the synthesized compounds, which was significantly higher than that of celecoxib in the carrageenin rat paw edema model and with milder ulcer scoring than that of indomethacin in the ulcerogenicity screening.
TL;DR: Docking studies provided insights into the putative binding mode in SmHDAC8 and allowed rationalization of the observed selectivity profile.
Abstract: Schistosoma mansoni histone deacetylase 8 (SmHDAC8) has been recently identified as a new potential target for the treatment of schistosomiasis. A series of newly designed and synthesized alkoxyamide-based and hydrazide-based HDAC inhibitors were tested for inhibitory activity against SmHDAC8 and human HDACs 1, 6, and 8. The front runner compounds showed submicromolar activity against SmHDAC8 and modest preference for SmHDAC8 over its human orthologue hHDAC8. Docking studies provided insights into the putative binding mode in SmHDAC8 and allowed rationalization of the observed selectivity profile.