One-pot multicomponent synthesis of novel 3, 4-dihydro-3-methyl-2(1H)-quinazolinone derivatives and their biological evaluation as potential antioxidants,enzyme inhibitors,antimicrobials, cytotoxic and anti-inflammatory agents

A series of novel 3, 4-dihydro-3-methyl-2(1H)-quinazolinone derivatives with substituted amine moieties (1–13) and substituted aldehyde (S) were designed and synthesized by a reflux condensation reaction in the presence of an acid catalyst to get N-Mannich bases. Mannich bases were evaluated pharmacologically for their antioxidant, α-amylase enzyme inhibition, antimicrobial, cell cytotoxicity and anti-inflammatory activities. Most of the compounds exhibited potent activities against these bioassays. Among them, SH1 and SH13 showed potent antioxidant activity against DPPH free radical at IC₅₀ of 9.94 ± 0.16 µg/mL and 11.68 ± 0.32 µg/mL, respectively. SH7, SH10 and SH13 showed significant results in TAC and TRP antioxidant assays, comparable to that of ascorbic acid. SH2 and SH3 showed potent activity in inhibiting α-amylase enzyme at IC₅₀ of 10.17 ± 0.23 µg/mL and 9.48 ± 0.17 µg/mL, respectively, when compared with acarbose (13.52 ± 0.19 µg/mL). SH7 was the most active against gram-positive and gram-negative bacterial strains, SH13 being the most potent against P. aeruginosa by inhibiting its growth up to 80% (MIC = 11.11 µg/mL). SH4, SH5 and SH6 exhibited significant activity against some fungal strains. Among the thirteen synthesized compounds (SH1-SH13), four were screened out based on the results of brine shrimp lethality assay (LD₅₀) and cell cytotoxicity assay (IC₅₀), to determine their anti-cancer potential against Hep-G2 cells. The study was conducted for 24, 48, and 72 h. SH12 showed potent results at IC₅₀ of 6.48 µM at 72 h when compared with cisplatin (2.56 µM). An in vitro nitric oxide (NO) assay was performed to shortlist compounds for in vivo anti-inflammatory assay. Among shortlisted compounds, SH13 exhibited potent anti-inflammatory activity by decreasing the paw thickness to the maximum compared to the standard, acetylsalicylic acid (ASA).     

Optimization of pyrazolo[1,5-a]pyrimidine based compounds with pyridine scaffold: Synthesis,biological evaluation and molecular modeling study

BackgroundPyrazolopyrimidine heterocycle and its isosteres represent the main scaffold for many pharmacologically active drugs including anti-inflammatory agents. The COX-2 inhibitors are the principal gate for the design of new safe and potent anti-inflammatory agents.MethodsNovel derivatives of pyrazolo[1,5-a] pyrimidines were synthesized and screened in vivo and in vitro for their anti-inflammatory potential.ResultsWithin the constructed compounds, compound 11 was the most active compound on IL-6 and TNF-α (percentage inhibition = 80 and 89%, respectively). In addition, compound 12 displayed the most inhibitory effect towards COX-2 (IC₅₀ = 1.11 µM), whereas compound 11 recorded the highest COX-2 selectivity (S.I = 8.97). The target derivatives 11–14 displayed good edema inhibitory potential (46–68%) and compound 11 was the most potent candidate (ED₅₀ = 35 mg/kg). Additionally, the most potent sPLA2-V inhibitors were compounds 11 and 13 (IC₅₀ = 1 and 1.7 µM respectively). Regarding activity towards 15-LOX, derivative 12 was the most active compound with IC₅₀ = 5.6 µM revealing higher inhibitory activity than nor-dihydroguaiaretic acid (IC₅₀ = 8.5 µM). To confirm the anti-inflammatory potential of the target derivatives, molecular modeling was performed inside COX-2 and 15-LOX active sites.ConclusionDisplay discoveries increment the plausibility that these pyrazolo[1,5-a]pyrimidines might act as a beginning point for the improvement of anti-inflammatory agents.     

Design,synthesis of new novel quinoxalin-2(1H)-one derivatives incorporating hydrazone,hydrazine, and pyrazole moieties as antimicrobial potential with in-silico ADME and molecular docking simulation

A series of 6-(morpholinosulfonyl)quinoxalin-2(1H)-one based hydrazone, hydrazine, and pyrazole moieties were designed, synthesized, and evaluated for their in vitro antimicrobial activity. All the synthesized quinoxaline derivatives were characterized by IR, NMR (¹H /¹³C), and EI MS. The results displayed good to moderate antimicrobial potential against six bacterial, and two fungal standard strains. Among the tested derivatives, six quinoxalin-2(1H)-one derivatives 4a, 7, 8a, 11b, 13, and 16 exhibited a significant antibacterial activity with MIC values (0.97–62.5 µg/mL), and MBC values (1.94–88.8 µg/mL) compared with Tetracycline (MICs = 15.62–62.5 µg/mL, and MBCs = 18.74–93.75 µg/mL), and Amphotericin B (MICs = 12.49–88.8 µg/mL, and MFC = 34.62–65.62 µg/mL). In addition, according to CLSI standards, the most active quinoxalin-2(1H)-one derivatives demonstrated bactericidal and fungicidal behavior. Moreover, the most active quinoxaline derivatives showed a considerable antibacterial activity with bactericidal potential against multi-drug resistance bacteria (MDRB) strains with MIC values ranged between (1.95–15.62 µg/mL), and MBC values (3.31–31.25 µg/mL) near to standard Norfloxacin (MIC = 0.78–3.13 µg/mL, and MBC = 1.4–5.32 µg/mL. Further, in vitro S. aureus DNA gyrase inhibition activity were evaluated for the promising derivatives and displayed potency with IC₅₀ values (10.93 ± 1.81–26.18 ± 1.22 µM) compared with Ciprofloxacin (26.31 ± 1.64 µM). Interestingly, these derivatives revealed as good immunomodulatory agents by a percentage ranging between 82.8 ± 0.37 and 142.4 ± 0.98 %. Finally, some in silico ADME, toxicity prediction, and molecular docking simulation were performed and showed a promising safety profile with good binding mode.     

Design and synthesis of some novel pyridothienopyrimidine derivatives and their biological evaluation as antimicrobial and anticancer agents targeting EGFR enzyme

A new series of pyridothienopyrimidine derivatives was designed and evaluated as antimicrobial and anticancer agents. The target compounds were synthesized starting with 3-aminothieno[2,3-b]pyridine-2-carboxamide derivative 1 which underwent cyclocondensation reaction with aromatic aldehydes to give the key intermediates 2a,b. By further treatment of 2a,b with various reagents, the target 2,4-disubstituted-pyrido[3′,2′:4,5]thieno[2,3-d]pyrimidines 3a,b–11a,b were obtained. To evaluate the antimicrobial activity of the new compounds, they were tested against five bacterial and five fungal strains. Compounds 6c, 8b, 9a and 9b revealed the most significant antimicrobial activity against the tested microorganisms with MIC values range (4–16 μg/mL). Also, compounds 2a,b–11a,b were screened for their in vitro cytotoxic activity against HepG-2 and MCF-7 cancer cell lines compared with doxorubicin and cisplatin as references drugs. Moreover, compounds (2b, 4a, 6a, 7b, 7c and 9a) which exhibited the most potent anticancer activity, were further subjected to EGFR^WT enzyme inhibition assay utilizing erlotinib as a standard drug. The compounds 6a, 7b, 7c and 9a which showed the most promising suppression effects were also evaluated as inhibitors against the mutant forms EGFR^L858R and EGFR^T790M. The 4-aminopyrazolone analogue 9a showed superior anticancer activity against both HepG-2 and MCF-7 cell lines (IC50 = 1.27, 10.80 μM, respectively) and more potent enzymatic inhibition activity against EGFR^WT and its mutant forms EGFR^L858R and EGFR^T790M than that obtained by erlotinib (IC₅₀ = 0.021, 0.053, 0.081 µM, respectively, IC_50erlotinib; 0.027, 0.069, 0.550 µM, respectively). Finally, the molecular docking study showed good binding patterns of the most active compounds with the prospective target EGFR^WT.     

Potential enzyme inhibitor triazoles from aliphatic esters: Synthesis,enzyme inhibition and docking studies

Enzyme inhibitors are vital aspects for studying enzymes and are employed as drugs to treat certain disorders, thus implying pivotal role in drug discovery. In the current study, a series of triazole compounds 4(a-o) were synthesised to explore their inhibitory potential against α-glucosidase and urease enzymes. These derivatives with dichlorophenyl substituents were prepared by cyclization of thiosemicarbazides and their structures were confirmed through spectroanalytical techniques. The in vitro biological screening revealed that the compounds 4a, 4b, 4k, 4l, 4m, 4o having IC₅₀ values of 121.09 ± 1.25, 137.22 ± 0.22, 110.4 ± 2.4, 114.79 ± 1.1, 146.72 ± 1.29, 94.21 ± 0.15 [µM] respectively, exhibited good potential α-glucosidase inhibition, in comparison to Acarbose: IC₅₀ 51.23 µM, while the compounds 4a, 4b, 4c, 4k, 4l, having IC₅₀ values of 48.52 ± 0.39, 52.22 ± 1.37, 60.98 ± 0.34, 37.06 ± 0.51, 38.66 ± 1.7 [µM] respectively exhibited good potential for urease inhibition near to standard(Thiourea: IC₅₀ 24.14 [µM]). These in vitro findings were accompanied further by molecular docking simulations, which revealed significant binding interactions of the synthesized derivatives within the active sites of the enzymes.     

2-methylindole analogs as cholinesterases and glutathione S-transferase inhibitors: Synthesis,biological evaluation,molecular docking,and pharmacokinetic studies

In this study, we aimed to (i) synthesize new 2-methylindole analogs containing various amino structures, pyrrolidine, piperidine, morpholine, and substituted phenyl groups through structural and molecular modifications, (ii) evaluate the pharmaceutical potential of 2-methylindole analogs via assessing enzyme inhibitory activity against glutathione S-transferase (GST), acetylcholinesterase (AChE), and butyrylcholinesterase (BChE), (iii) predict ADMET and pharmacokinetic properties of the synthesized 2-methylindole analogs, (iv) reveal the possible interactions between the synthesized 2-methylindole analogs with GST, AChE, and BChE enzymes using several molecular docking software. In vitro enzyme inhibition assays showed that the synthesized indole analogs exhibited moderate to good inhibitory activities against GST, AChE, and BChE enzymes. Briefly, the inhibitory activities of the analogs 4b and 4i against AChE, 4a and 4b against BChE, and analogs 1 and 4i against GST were detected to be higher or close to the standard inhibitor compounds. The analog 4b was detected to have the best inhibitory activity against both AChE and BChE enzymes with the lowest IC₅₀ values as 0.648 µM for AChE and 0.745 µM for BChE. The analyses of enzyme inhibition relationship with the synthesized analogs could help to design new analogs for the inhibitors of cholinergic and glutathione pathways based on the indole derivatives.     

Arylnaphthalide lignans from Saussurea medusa and their anti-inflammatory activities

Five new arylnaphthalide lignans (1 ? 4a/4b), together with five known analogues (5–9), were isolated from whole plants of Saussurea medusa. Compound 4 was characterized as an aryltetralin lignan with an unusual C-7′-C-9 oxygen bridge group, and a chiral HPLC analysis was carried out to afford one pair of enantiomers (4a/4b). Structures of the new compounds were elucidated by extensive spectroscopic and electronic circular dichroism (ECD) calculations. All compounds were firstly isolated from S. medusa, and compounds 1–5, 7 and 8 had never been obtained from the genus Saussurea previously. Furthermore, this is the first report of arylnaphthalide lignans isolated from S. medusa. anti-inflammatory activities of the compounds were evaluated by determining their inhibitory activities on the production of NO by LPS-stimulated RAW 264.7 cells. Compounds (?)-4a and 5 exerted the significant inhibition activities with IC₅₀ values of 13.4 ± 1.5 and 15.7 ± 1.1 μM, respectively, which even exceeded the positive control quercetin (IC₅₀ = 15.9 ± 1.2 μM). Compounds 2, (+)-4b, 6 and 9 exhibited moderate inhibitory activities with IC₅₀ values ranging from 19.7 ± 1.9 to 47.4 ± 3.1 μM. Further analysis by molecular docking showed that almost all the active compounds could interact with the amino acid residues of iNOS proteins, which also supported their anti-inflammatory activities.     

Synthesis,biological evaluation and molecular docking study of pyrimidine based thiazolidinone derivatives as potential anti-urease and anti-cancer agents

Hybrid analogs containing molecules are always the choice of different synthetic researcher due to their diverse biological applications and significantly more efficient. Heterocyclic being a good inhibitors against varied disease are most commonly used in drug designing and development. The current study also addressed the synthesis of pyrimidine-based thiazolidinone derivatives (1–13) using stepwise processes and their structure was confirmed using various characterization techniques such as ¹HNMR, ¹³CNMR, and HREI-MS. Furthermore, the biological significances of the synthesized scaffolds were also explored and proved to be as anti-urease and anti-cancer moieties. Their inhibitory potentials were determined using the minimum inhibitory concentration (MIC) in the presence of their standard drugs, Thiourea (IC₅₀ = 8.20 ± 0.20 µM) and Tetrandrineb (IC₅₀ = 12.30 ± 0.10 µM) respectively. Structure activity relationship (SAR) was established for all the synthesized scaffolds and compared their inhibitory potentials in which scaffolds 3 (IC₅₀ = 2.30 ± 0.30 and 3.20 ± 0.50 µM), 6 (IC₅₀ = 3.10 ± 0.20 and 6.20 ± 0.10 µM), 7 (IC₅₀ = 3.20 ± 0.20 and 3.80 ± 0.30 µM) and 10 (IC₅₀ = 4.20 ± 0.20 and 5.10 ± 0.30 µM) exhibited the most influential activity. These compounds were subsequently examined using molecular docking experiments, which evaluate the binding interaction of ligands with enzyme active sites.     

Synthesis,evaluation and docking studies of some 4-thiazolone derivatives as effective lipoxygenase inhibitors

Some promising 4-thiazolone derivatives as lipoxygenase inhibitors were designed, synthesized, characterized and evaluated for anti-inflammatory activity and respective ulcerogenic liabilities. Compounds (1b, 1e, 3b, and 3e) exhibited considerable in vivo anti-inflammatory activity (57.61, 79.35, 75.00, and 79.35%) against carrageenan-induced rat paw edema model, whereas compounds (1e, 3b, and 3e) were found active against the arachidonic acid-induced paw edema model (55.38, 55.38, and 58.46%). The most potent compound (3e) exhibited lesser ulcerogenic liability compared to the standard diclofenac and zileuton. Further, the promising compounds (1e and 3e) were evaluated for in vitro lipoxygenase (LOX; IC₅₀?=?12.98 µM and IC₅₀?=?12.67 µM) and cyclooxygenase (COX) inhibition assay (COX-1; IC₅₀?>?50 µM and, COX-2; IC₅₀?>?50 µM). The enzyme kinetics of compound 3e was evaluated against LOX enzyme and supported by in silico molecular docking and molecular dynamics simulations studies. Overall, the results substantiated that 5-benzylidene-2-phenyl-4-thiazolones are promising pharmacophore for anti-inflammatory activity.     

Synthesis,in vitro evaluation,and molecular docking studies of benzofuran based hydrazone a new inhibitors of urease

This work has described the synthesis of novel class (1–25) of benzofuran based hydrazone. The hybrid scaffolds (1–25) of benzofuran based hydrazone were evaluated in vitro, for their urease inhibition. All the newly synthesized analogues (1–25) were found to illustrate moderate to good urease inhibitory profile ranging from 0.20 ± 0.01 to 36.20 ± 0.70 µM. Among the series, compounds 22 (IC₅₀ = 0.20 ± 0.01 µM), 5 (IC₅₀ = 0.90 ± 0.01 µM), 23 (IC₅₀ = 1.10 ± 0.01 µM) and 25 (IC₅₀ = 1.60 ± 0.01 µM) were found to be the many folds more potent than thiourea as standard inhibitor (IC₅₀ = 21.86 ± 0.40 µM). The elevated inhibitory profile of these analogues might be due to presence of dihydroxy and flouro groups at different position of phenyl ring B attached to hydrazone skeleton. These dihydroxy and fluoro groups bearing compounds have shown many folds better inhibitory profile through involvement of oxygen of dihydroxy groups in hydrogen bonding with active site of enzymes. Various types of spectroscopic techniques such as ¹H-, ¹³C- NMR and HREI-MS spectroscopy were used to confirm the structure of all the newly developed compounds. To find SAR, molecular docking studies were performed to understand, the binding mode of potent inhibitors with active site of enzymes and results supported the experimental data.     

Synthesis,anticancer evaluation,and molecular modeling study of new 2-(phenylamino)pyrazolo[1,5-a]pyrimidine analogues

The reaction of 3-amino-5-phenylaminopyrazoles 2 with 3-(dimethylamino) acrylonitrile derivatives resulted in a series of substituted pyrazolopyrimidine analogues 4 and 6. The DFT studies of the isolated compounds showed that the frontier molecular orbitals energy gap was close and in the 2.65–2.81 eV range where the derivative 6b has the lowest and both of 4a and 4c have the highest values. Meanwhile, the anticancer activity of the newly synthesized pyrazolopyrimidine analogues have been tested against several different cell lines (MCF-7, PC3, Hep-2 and WI38). The investigated pyrazolopyrimidines showed remarkable cytotoxicity activity against the MCF-7 and Hep-2 cell lines. In comparison to the effects of 5-fluorouracil, IC₅₀ = 10.19 ± 0.42 and 7.19 ± 0.47, compounds 6a-c demonstrated potential anticancer activity with IC₅₀ values for MCF-7 (10.80 ± 0.36–19.84 ± 0.49 μM) and Hep-2 (8.85 ± 0.24–12.76 ± 0.16 μM). Important details regarding the protein's binding sites were disclosed when the produced analogues docked with the crystal structure of the KDM5A protein, which was located in the protein data library.     

Synthesis and in vitro activity of a non-epimerizable analog of the angiotensin-converting enzyme inhibitor A58365A

The 3-methyl-substituted analog (±)-3 of the angiotensin converting enzyme inhibitor A58365A (1) was synthesized from lactone 4 and amino acid ester 16, via key intermediates 18, 19 and 21a,b. Compound (±)-3 was found to possess powerful ACE inhibitory activity (IC₅₀ = ca 500 nM), as judged by in vitro tests against porcine kidney ACE, under conditions in which the commercial drug captopril has IC₅₀ = 280 nM.     

Design,synthesis, antimicrobial evaluations and in silico studies of novel pyrazol-5(4H)-one and 1H-pyrazol-5-ol derivatives

A new series of 1,4-disubstituted 3-methylpyrazol-5(4H)-one derivatives were synthesized by reacting various substituted aromatic aldehydes with 3-methylpyrazol-5(4H)-one derivatives through Knoevenagel condensation by conventional as well as by exposure to microwave irradiations. After that newly synthesized compounds of 1,4-disubstituted 3-methyl-1H-pyrazol-5-ol were prepared from these derivatives by reduction reaction of sodium borohydride at 0–5 °C. Sixty-four heterocyclic compounds containing a pyrazole moiety were synthesized with good to excellent yields (51 to 91%). Compounds (3d, 3m, 4a, 4b, 4d, and 4g) showed potent antibacterial activity against MSSA (Methicillin-susceptible strains of Staphylococcus aureus) and MRSA (Methicillin-resistant strains of Staphylococcus aureus) with MIC (the minimum inhibitory concentration) ranging between 4 and 16 µg/mL as compared to ciprofloxacin (MIC = 8–16 µg/mL). Compounds (4a, 4h, 4i, and 4l) showed potent antifungal activity against Aspergillus niger with MIC ranging between 16 and 32 µg/mL as compared to fluconazole (MIC = 128 µg/mL). In particular, compound 4a exhibited the strongest activity among the synthesized compounds in both bacterial and fungal strains with MIC ranging between 4 and 16 µg/mL. Furthermore, the nine most active compounds showed a good ADMET (absorption, distribution, metabolism, excretion, and toxicity) profile in comparison to ciprofloxacin and fluconazole as reference drugs. Molecular docking predicted that DHFR (dihydrofolate reductase) protein from Staphylococcus aureus and NMT (N-myristoyl transferase) protein from Candida albicans are the most suitable targets for the antimicrobial activities of these potent compounds.     

Design,synthesis, crystal structures and biological evaluation of some 1,3-thiazolidin-4-ones as dual CDK2/EGFR potent inhibitors with potential apoptotic antiproliferative effects

A series of novel thiazolidine-4-one derivatives was synthesized by reacting 1,4-disubstituted hydrazine carbothioamides with diethyl azodicarboxylate. The structures were confirmed by spectroscopic data as well as single-crystal X-ray analyses. The antiproliferative activity of the synthesized compounds was investigated against four human cancer cell lines using an MTT assay. Compounds 5d, 5e, and 5f revealed the most potent antiproliferative activity with GI₅₀ values ranging from 0.70 µM to 1.20 µM, compared to doxorubicin GI₅₀ value = 1.10 µM. Compounds 5d, 5e, and 5f were further investigated for their inhibitory activities against CDK2 and EGFR as potential targets for their molecular mechanism. Compounds 5e and 5f have showed potent inhibitory activity to CDK2 enzyme with IC₅₀ values of 18 and 14 nM, which is more potent than the reference dinaciclib (IC₅₀ = 20 nM). Moreover, compounds 5e and 5f were the most potent EGFR inhibitors, with IC₅₀ values of 93 and 87 nM, respectively, compared to the reference erlotinib (IC₅₀ = 70 nM). In addition, the most potent derivatives were tested for their apoptotic activity against caspases 3, 8, and 9, and the results showed that compounds 5d, 5e, and 5f revealed a greater increase in active caspases 3,8 and 9 than doxorubicin. Also, compounds 5d, 5e, and 5f elevated cytochrome C levels in the MCF-7 human breast cancer cell line by about 15.5, 15.8, and 16.5 times, respectively. Finally, a molecular docking study was performed to investigate the binding sites of these compounds within the active sites of CDK2 and EGFR targets, and the results confirmed that the most potent CDK2 and EGFR inhibitor 5h also have showed the highest docking score.     

Biology-oriented drug synthesis of nitrofurazone derivatives: Their α-glucosidase inhibitory activity and molecular docking studies

In the present study, twenty (20) structural variants of nitrofurazone were synthesized based on BIODS (Biology-oriented drug synthesis) approach. The structure elucidation of the synthetic molecules (1–20) was carried out using different spectroscopic techniques, and their α-glucosidase inhibitory activity was also determined. The synthetic molecules 1–20 exhibited good α-glucosidase inhibition than the parent, nitrofurazone. Four compounds 2, 4, 6, and 7 showed potential inhibition against α-glucosidase with IC₅₀ values ranging between 0.63 ± 0.25–1.29 ± 0.46 µM as compared to the standard acarbose (IC₅₀ = 2.05 ± 0.41 µM). Nevertheless, compounds 15 (IC₅₀ = 0.74 ± 0.12 µM), and 19 (IC₅₀ = 0.54 ± 0.3 µM) also displayed good α-glucosidase inhibition and compound 19 was the most active compound of the series. Kinetic study of the active compounds 7 and 19 was also carried out to confirm the mode of inhibition. The binding interactions of the most active compounds within the active site of enzyme were determined by molecular docking. Moreover, molecular dynamic simulation of compound 19 was also performed in order to determine the stability of the overall complex (α-glucosidase + c19) in an explicit watery environment. The synthetic molecules were predicted as non-cytotoxic, however, seven compounds 1, 3, 4, 9, 10, 11, and 12 were predicted as carcinogenic.     

Identification of novel oxadiazole-based benzothiazole derivatives as potent inhibitors of α-glucosidase and urease: Synthesis,in vitro bio-evaluation and their in silico molecular docking study

This research work represents a synthetic approach for the development of hybrids derivatives of oxadiazole-based benzothiazole (1–17) and diversity in derivatives was achieved using variety of aryl ring of S-substituted benzothiazole to see the effect on the biological activities. All the synthesized derivatives were evaluated for their in vitro α-glucosidase and urease inhibitory potential. The α-glucosidase and urease inhibition profile of the new derivatives represents moderate to good inhibitory potential with IC₅₀ values ranging from 4.60 ± 1.20 µM to 48.40 ± 7.70 µM (α-glucosidase) and 8.90 ± 2.80 to 57.30 ± 7.70 µM (urease) respectively. The results were compared to standard acarbose (38.60 ± 4.50 µM) and thiourea (58.70 ± 6.80 µM) drugs respectively. Among the synthesized series, the analogs 1 having IC₅₀ values of and 4.60 ± 1.20 (α-glucosidase), 8.90 ± 2.80 (urease) and 2 with IC₅₀ values of 5.60 ± 1.60 (α-glucosidase) and 10.90 ± 2.10(urease) were found to be significantly active against targeted α-glucosidase and urease enzymes. The structure of all the newly synthetics scaffolds were confirmed by using different types of spectroscopic techniques such as HREI-MS, ¹H- and ¹³C- NMR spectroscopy. The molecular docking studies of the synthesized derivatives showed good correlations with the experimental findings. The binding modes of active compounds and their interactions with active site residues revealed them as possible anti-diabetics and anti-urease leads. The degree of activity and docking studies displayed by the novel innovative structural hybrids of oxadiazole-based benzothiazole moieties make these compounds new active leads and promising candidates for the development of anti-diabetics and anti-urease agents.     

The design of fluoroquinolone-based cholinesterase inhibitors: Synthesis,biological evaluation and in silico docking studies

An enhanced acetylcholinesterase (AChE) activity is a hallmark in early stages of Alzheimer's ailment that results in decreased acetylcholine (ACh) levels, which in turn leads to cholinergic dysfunction and neurodegeneration. Consequently, inhibition of both AChE and butyrylcholinesterase (BChE) is important to prolong ACh activity in synapses for the enhanced cholinergic neurotransmission. In this study, a series of new fluoroquinolone derivatives (7a-m) have synthesized and evaluated for AChE and BChE inhibitory activities. The screening results suggested that 7 g bearing ortho fluorophenyl was the most active inhibitor against both AChE and BChE, exhibiting IC₅₀ values of 0.70 ± 0.10 µM and 2.20 ± 0.10 µM, respectively. The structure–activity relationship (SAR) revealed that compounds containing electronegative functions (F, Cl, OMe, N and O) at the ortho position of the phenyl group exhibited higher activities as compared to their meta- and/or para substituted counterparts. Molecular docking studies of synthesized compounds 7a, 7g, 7j and 7l docked into the active site of AChE and 7a-f docked into the active site of BChE revealed that these compounds exhibited conventional H-bonding along with π-π interaction with the active residues of AChE through their electronegative functions and phenyl ring, respectively. All the synthesized compounds are characterized by spectroscopic methods including FT-IR, ¹H- and ¹³C NMR as well as elemental analysis. This is the first example of fluoroquinolone-based cholinesterase inhibitors.     

Design,synthesis and docking studies of new hydrazinyl-thiazole derivatives as anticancer and antimicrobial agents

Increase in the number of infections caused by pathogenic microbes in cancer patients has prompted the searcher to invest in the development of agents having dual anticancer and antimicrobial properties. The present study is concerned with synthesis and screening for anticancer and antimicrobial activity of a series of 5-hydrazinyl-2-(2-(1-(thien-2-yl)ethylidene)hydrazinyl)thiazole derivatives. The structure elucidation of the synthesized hydrazinyl thiazole derivatives was illustrated by spectroscopic and elemental analysis. All the newly synthesized compounds 5a-p were evaluated for in-vitro cytotoxic activity against breast carcinoma (MCF-7 cell line), hepatocellular carcinoma (HePG-2) and colorectal cancer (HCT-116) cell lines using MTT assay method. Compounds 5 g, 5h showed broad spectrum activity against three cancer cell lines with IC₅₀ ranged from 3.81 to 11.34 µM in compared to the reference drug Roscovitine (IC₅₀ = 9.32 to 13.82 µM), while compounds 5 l and 5 m were found to be more selective against HePG-2 and HCT-116 cell line (IC₅₀ = 9.29 and 8.93 µM respectively) and compound 5j was more selective against HePG-2 and MCF-7 cell lines (IC₅₀ = 6.73 and 10.87 µM respectively). The inhibitory activity of the most promising compounds was tested against the EGFR and ARO enzymes and were further tested for apoptosis and Annexin V/PI staining. The results of enzyme-based tests revealed that the tested compound 5j has a dual inhibitory effect on the EGFR and ARO enzymes with IC₅₀ = 82.8 and 98.6 nM respectively in compared to the reference drugs Erlotinib and Letrozole (IC₅₀ = 62.4 and 79 nM respectively). Furthermore, the majority of the tested hydrazinyl thiazole derivatives exhibited significant antimicrobial activity against the used pathogenic microbes species. Compounds 4b, 5h, 5j and 5 m exerted a good antibacterial and antifungal activity against all tested pathogenic microbes. Therefore, it was concluded that compounds 5 h, 5j and 5 m proved to possess dual anticancer and antimicrobial agent and may serves as a useful lead compounds in search for further modification or derivatization to give more potent and selective agents.     

Synthesis and antimicrobial,antiproliferative and anti-inflammatory activities of novel 1,3,5-substituted pyrazoline sulphonamides

The design of novel molecules is imperative for the discovery of potent drugs in the medicinal chemistry field. In this work, new 1,3,5-substituted pyrazoline sulphonamides were synthesised using a two-step process with microwave assistance and evaluated biologically for their antimicrobial, antiproliferative, and anti-inflammatory properties. Most of the sulphonamides bearing 3-OH or 4-Cl groups exhibited significant inhibition of two Gram-positive bacteria, Bacillus subtillis and Staphylococcus aureus, and the yeast Candida albicans. Six compounds showed good activity against the cancer cell lines cervix carcinoma (Hep-2C) and human lung carcinoma (A549) with IC₅₀ in the range 16.03 ± 1.63 to 22.75 ± 0.19 μM and 18.64 ± 1.02 to 20.66 ± 2.09 μM, respectively, and exhibited low toxicity against mammalian Vero cells. In evaluating in vitro anti-inflammatory behaviour, five compounds showed high inhibition of NO production over the standard reference, with low toxicity against murine macrophage cell line RAW 264.7. Further investigation found that two compounds, 1b and 18b, exhibited the highest activity when testing mouse ear oedema. The findings are promising for the discovery of potent new drugs.     

Synthesis and anti-α-glucosidase activity evaluation of betulinic acid derivatives

In this article, a series of betulinic acid derivatives (3a ～ 3u, 4a ～ 4e) were synthesized through a stepwise structure optimization and evaluated for their anti-α-glucosidase activities. All synthesized derivatives exhibited stronger anti-α-glucosidase activities (IC₅₀: 0.56 ± 0.05 ～ 3.99 ± 0.23 μM) than betulinic acid (IC₅₀: 7.21 ± 0.58 μM) and acarbose (IC₅₀: 611.45 ± 15.51 μM). Compound 3q presented the outstanding inhibitory activity (IC₅₀: 0.56 ± 0.05 μM), which was ～ 1100 time stronger than that of acarbose. Compound 3q was revealed as a reversible and noncompetitive α-glucosidase inhibitor by inhibitory mechanism assay. Fluorescence spectra, 3D fluorescence and CD spectra results showed that the interaction of compound 3q with α-glucosidase caused the conformational and secondary structure content change of α-glucosidase. Finally, the molecular docking simulated the interaction between compound 3q with α-glucosidase and the physicochemical parameter was assessed using SwissADME software.