Design,synthesis and evaluation of novel oxazaphosphorine prodrugs of 9-(2-phosphonomethoxyethyl)adenine (PMEA,adefovir) as potent HBV inhibitors

A series of novel oxazaphosphorine prodrugs of 9-(2-phosphonomethoxyethyl)adenine (PMEA, adefovir) were synthesized and their anti-hepatitis B virus (HBV) activity was evaluated in HepG2 2.2.15 cells, with adefovir dipivoxil as a reference drug. In the cell assays, compounds 7b and 7d exhibited anti-HBV activity comparable to that of adefovir dipivoxil, while compound 7c, with an IC₅₀ value of 0.12 μM, was found to be three times more potent than the reference compound. In vitro stability studies showed that (S_P,S)-7c, the diastereomer of compound 7c, was stable in human blood plasma but underwent rapid metabolism to release the parent drug PMEA in liver microsomes. The possible metabolic pathway of (S_P,S)-7c in human liver microsomes was described. These findings suggest that compound (S_P,S)-7c is a promising anti-HBV drug candidate for further development.     

Design and synthesis of parthenolide-SAHA hybrids for intervention of drug-resistant acute myeloid leukemia

A series of parthenolide-SAHA hybrids were synthesized and evaluated for their anti-AML activities against HL-60 and HL-60/ADR cell lines. The most active compound 26 exhibited high activity against HL-60/ADR cell line with IC₅₀ value of 0.15 μM, which demonstrated 16.8-fold improvement compared to that of the parent compound PTL (IC₅₀ = 2.52 μM). Moreover, it was six times more potent than the reference drug SAHA (IC₅₀ = 0.90 µM) and fifty-one times more potent than ADR (IC₅₀ = 7.72 µM). The preliminary molecular mechanism of 26 indicated that compound 26 could significantly induce apoptosis of HL-60/ADR cells. The effect of compound 26 was mainly through mitochondria pathway. Further investigation revealed that the protein level of HDAC1 and HDAC6 were reduced after the treatment of compound 26 with a dose-dependent manner. Compound 26 could significantly decrease ABCC1 expression, which increased the accumulation of intracellular drug for overcoming the drug resistance. On the base of these results, compound 26 might be considered as a promising candidate for further evaluation as a potential anti-AML drug.     

Synthesis,anticancer effect and molecular modeling of new thiazolylpyrazolyl coumarin derivatives targeting VEGFR-2 kinase and inducing cell cycle arrest and apoptosis

New thiazolylpyrazolyl coumarin derivatives were synthesized and tested for their anticancer potential in vitro against five different human cell lines, including breast MCF-7, lung A549, prostate PC3, liver HepG2 and normal melanocyte HFB4. Breast carcinoma revealed higher sensitivity towards compounds 7a, 8c, 9b, 9c and 9d with IC₅₀ values ranging from 5.41 to 10.75 μM in comparison to the reference drug doxorubicin (IC₅₀ = 6.73 μM). In addition, no noticeable toxicity was exhibited towards normal cells HFB4. Moreover, in vitro studies of the VEGFR-2 inhibition in human breast cancer MCF-7 cell line for the promising cytotoxic compounds showed that compounds 7a, 8c, 9b, 9c and 9d were potent inhibitors at low micromolar concentrations (IC₅₀ = 0.034–0.582 μM) compared to the reference drug, sorafenib (IC₅₀ = 0.019 μM). Several theoretical and experimental studies were done to reveal the molecular mechanisms that control breast carcinoma metastasis. The mechanistic effectiveness in cell cycle progression, apoptotic induction and gene regulation were assessed for the promising compound 9d due to its remarkable cytotoxic activity against MCF-7 and significant VEGFR-2 inhibition. Flow cytometeric analysis showed that compound 9d induced cell growth cessation at G2/M phase and increased the percentage of cells at pre-G1 phase that stimulates the apoptotic death of MCF-7 cells. Furthermore, real time PCR assay illustrated that compound 9d up regulated p53 gene expression and elevated Bax/Bcl-2 ratio which confirmed the mechanistic pathway of compound 9d. Moreover, the apoptotic induction of breast cancer cells MCF-7 was enhanced effectively through activation of caspases-7 and 9 by compound 9d. On the other hand, a set of in silico methods such as molecular docking, molecular dynamics simulation, QSAR analysis as well as ADMET analysis was performed in order to study the protein-ligand interactions and the relationship between the physicochemical properties and the inhibitory activity of the promising compounds 7a, 8c and 9d. Based on the aforementioned findings, compound 9d could be considered as effective apoptosis modulator and promising lead for future development of new anti-breast cancer agents.     

Synthesis,characterization and biological evaluation of some novel 2,4-thiazolidinediones as potential cytotoxic,antimicrobial and antihyperglycemic agents

A series of some novel 2,4-thiazolidinediones (TZDs) (2a–x) have been synthesized and characterized by FTIR, ¹H NMR, ¹³C NMR and LC mass spectral analysis. All the synthesized compounds were evaluated for their cytotoxicity, antimicrobial and in vivo antihyperglycemic activities. Among the tested compounds for cytotoxicity using Brine Shrimp Lethality assay, compound 2t ((Z)-5-(4-((E)-3-oxo-3-(thiophen-2-yl)prop-1-enyl)benzylidene)-1,3-thiazolidine-2,4-dione) exhibited significant inhibitory activity at ED₅₀ value 4.00 ± 0.25 μg/mL and this level of activity was comparable to that of the reference drug podophyllotoxin with ED₅₀ value 3.61 ± 0.17 μg/mL. Antimicrobial activity was screened using agar well diffusion assay method against selected Gram-positive, Gram-negative and fungal strains and the activity expressed as the minimum inhibitory concentration (MIC) in μg/mL. From the results of antimicrobial activity compound 2s ((Z)-5-(4-((E)-3-(3,5-bis(benzyloxy)phenyl)-3-oxoprop-1-enyl)benzylidene)-1,3-thiazolidine-2,4-dione) was found to be the most active against all the tested strains of microorganisms with MIC value 16 μg/mL. In vivo antihyperglycemic effect of twenty four TZDs (2a–x) at different doses 10, 30 and 50 mg/kg b.w (oral) were assessed using percentage reduction of plasma glucose (PG) levels in streptozotocin-induced type II diabetic rat models. From the results, the novel compound 2x ((Z)-5-(4-((E)-3-(9H-fluoren-2-yl)-3-oxoprop-1-enyl)benzylidene)-1,3-thiazolidine-2,4-dione) exhibited considerably potent blood glucose lowering activity than that of the standard drug rosiglitazone and it could be a remarkable starting point to evaluate structure–activity relationships and to develop new lead molecules with potential cytotoxicity, antimicrobial and antihyperglycemic activities. In addition molecular docking studies were carried out against PPARγ molecular target using Molegro Virtual Docker v 4.0 to accomplish preliminary confirmation of the observed in vivo antihyperglycemic activity.     

Synthesis,anticancer, structural,and computational docking studies of 3-benzylchroman-4-one derivatives

A series of 3-Benzylchroman-4-ones were synthesized and screened for anticancer activity by MTT assay. The compounds were evaluated against two cancerous cell lines BT549 (human breast carcinoma), HeLa (human cervical carcinoma), and one noncancerous cell line vero (normal kidney epithelial cells). 3b was found to be the most active molecule against BT549 cells (IC₅₀?=?20.1?µM) and 3h against HeLa cells (IC₅₀?=?20.45?µM). 3b also exhibited moderate activity against HeLa cells (IC₅₀?=?42.8?µM). The molecular structures of 3h and 3i were solved by single crystal X-ray crystallographic technique. Additionally, the molecular docking studies between the tumour suppressor protein p53 with the lead compound 3h, which exhibited better anticancer activity against HeLa cells was examined.     

A new series of aryl sulfamate derivatives: Design,synthesis, and biological evaluation

Steroid sulfatase (STS) has recently emerged as a drug target for management of hormone-dependent malignancies. In the present study, a new series of twenty-one aryl amido-linked sulfamate derivatives 1a-u was designed and synthesized, based upon a cyclohexyl lead compound. All members were evaluated as STS inhibitors in a cell-free assay. Adamantyl derivatives 1h and 1p-r were the most active with more than 90% inhibition at 10 µM concentration and, for those with the greatest inhibitory activity, IC₅₀ values were determined. These compounds exhibited STS inhibition within the range of ca 25–110 nM. Amongst them, compound 1q possessing a o-chlorobenzene sulfamate moiety exhibited the most potent STS inhibitory activity with an IC₅₀ of 26 nM. Furthermore, to assure capability to pass through the cell lipid bilayer, compounds with low IC₅₀ values were tested against STS activity in JEG-3 whole-cell assays. Consequently, 1h and 1q demonstrated IC₅₀ values of ca 14 and 150 nM, respectively. Thus, compound 1h is 31 times more potent than the corresponding cyclohexyl lead (IC₅₀ value = 421 nM in a JEG-3 whole-cell assay). Furthermore, the most potent STS inhibitors (1h and 1p-r) were evaluated for their antiproliferative activity against the estrogen-dependent breast cancer cell line T-47D. They showed promising activity with single digit micromolar IC₅₀ values (ca 1–6 µM) and their potency against T-47D cells was comparable to that against STS enzyme. In conclusion, this new class of adamantyl-containing aryl sulfamate inhibitor has potential for further development against hormone-dependent tumours.     

Design,synthesis, anticancer evaluation and docking studies of new pyrimidine derivatives as potent thymidylate synthase inhibitors

Cancer is a perplexing and challenging problem for researchers. In this study, a series of 6-aryl-5-cyano-pyrimidine derivatives were designed, synthesized and evaluated for their anticancer activity against HePG-2, MCF-7 and HCT-116 cell lines. Compounds 2, 3d, 4a-c, 5, 8 and 12 displayed high anticancer activity, comparable to that of 5-fluorouracil. Additionally, those compounds with effective anticancer activity were further assessed for their ability to inhibit thymidylate synthase (TS) enzyme. All the tested compounds demonstrated a marked TS inhibitory activity (33.66–74.98%), with IC₅₀ ranging from 3.89 to 15.74 nM. Moreover, apoptosis studies were conducted on the most potent compound 8, to evaluate its proapoptotic potential. Interestingly, compound 8 induced the level of active caspase 3, and elevated the Bax/Bcl2 ratio 44 folds in comparison to the control. Finally, a molecular docking study was conducted to detect the probable interaction between the active compounds and the thymidylate synthase active site.     

Design,synthesis, biological evaluation and molecular modelling studies of indole glyoxylamides as a new class of potential pancreatic lipase inhibitors

A series of eighteen indole glyoxylamide analogues were synthesized, characterized and evaluated for their pancreatic lipase inhibitory activity. Porcine pancreatic lipase (Type II) was used with 4-nitrophenyl butyrate (as substrate) for the in vitro assay. Compound 8f exhibited competitive inhibition against pancreatic lipase with IC₅₀ value of 4.92 µM, comparable to that of the standard drug, orlistat (IC₅₀ = 0.99 µM). Compounds 7a-i and 8a-i were subjected to molecular docking into the active site of human PL (PDB ID: 1LPB) wherein compound 8f possessed a potential MolDock score of −153.037 kcal/mol. Molecular dynamics simulation of 8f complexed with pancreatic lipase, confirmed the role of aromatic substitution in stabilizing the ligand through hydrophobic interactions (maximum observed RMSD = 3.5 Å).     

EGFR inhibitors and apoptotic inducers: Design,synthesis, anticancer activity and docking studies of novel xanthine derivatives carrying chalcone moiety as hybrid molecules

One of the helpful ways to improve the effectiveness of anticancer agents and weaken drug resistance is to use hybrid molecules. therefore, the current study intended to introduce 20 novel xanthine/chalcone hybrids 9–28 of promising anticancer activity. Compounds 10, 11, 13, 14, 16, 20 and 23 exhibited potent inhibition of cancer cells growth with IC₅₀ ranging from 1.0 ± 0.1 to 3.5 ± 0.4 μM compared to doxorubicin with IC₅₀ ranging from 0.90 ± 0.62 to 1.41 ± 0.58 μM and that compounds 11 and 16 were the best. To verify the mechanism of their anticancer activity, compounds 10, 11, 13, 14, 16, 20 and 23 were evaluated for their EGFR inhibitory effect. The study results revealed that compound 11 showed IC₅₀ = 0.3 µM on the target enzyme which is more potent than staurosporine reference drug (IC₅₀ = 0.4 µM). Accordingly, the apoptotic effect of the most potent compounds 11 was extensively investigated and showed a marked increase in Bax level up to 29 folds, and down-regulation in Bcl2 to 0.28 fold, in comparison to the control. Furthermore, the effect of compound 11 on Caspases 3 and 8 was evaluated and was found to increase their levels by 8 and 14 folds, respectively. Also, the effect of compound 11 on the cell cycle and its cytotoxic effect were examined. Moreover, a molecular docking study was adopted to confirm mechanism of action.     

Design,synthesis and biological evaluation of 2,5-dimethylfuran-3-carboxylic acid derivatives as potential IDO1 inhibitors

Indoleamine 2,3-dioxygenase 1 (IDO1) plays a vital role in tumor immune escape and has emerged as a promising target for cancer immunotherapy. In this study, a novel series of 2,5-dimethylfuran-3-carboxylic acid derivatives were designed, synthesized and evaluated for inhibitory activities against IDO1, and their structure-activity relationship was investigated. Among these, compound 19a exhibited excellent IDO1 inhibitory activity (HeLa cellular IC₅₀?=?4.0?nM, THP-1 cellular IC₅₀?=?4.6?nM). Further molecular docking studies revealed that the compound 19a formed a coordinate bond with the heme iron through the carboxylic acid moiety. These results indicate that compound 19a is a potential IDO1 inhibitor for further investigation.     

Dihydrofolate reductase inhibition effect of 5-substituted pyrido[2,3-d]pyrimidines: Synthesis,antitumor activity and molecular modeling study

A new series of pyrido[2,3-d]pyrimidines 3–18 bearing substitution at C-5 position was synthesized. All compounds were tested for their in vitro antitumor activity against five human cancer cell lines namely; hepatocellular carcinoma (HePG2), breast carcinoma (MCF-7), human prostate carcinoma (PC3), colorectal carcinoma (HCT-116), and cervical carcinoma (Hela) using doxorubicin as a positive control. Compounds 3, 4, 9, 11, 13, 14, 15 and 17 exhibited the highest antitumor activity against the tested cell lines and were selected to screen their enzymatic inhibition against dihydrofolate reductase enzyme (DHFR) compared with the reference drug methotrexate (MTX), to explain the probable mechanism of action of the observed anticancer activity. Compound 11 displayed the highest inhibitory activity (IC₅₀ = 6.5 µM) among the tested compounds in comparison with MTX (IC₅₀ = 5.57 µM). Also, compounds 13 and 14 showed high inhibitory activity against DHFR with IC₅₀ values 7.1 and 8.7 µM, respectively. Comparative molecular modeling study was performed between DHFR inhibitors 11, 13 and 14 of the highest activity and 10 of the lowest activity among the eight inhibitors against MTX. Docking studies into the active site of DHFR domain showed good agreement with the obtained biological results. Finally, compound 11 was found to be best antitumor, DHFR inhibitor, and it induced the process of apoptosis at Pre-G phase and cell cycle arrest at G2/M phase in MCF-7 cells.     

Novel benzotriazole N-acylarylhydrazone hybrids: Design,synthesis, anticancer activity,effects on cell cycle profile,caspase-3 mediated apoptosis and FAK inhibition

A series of novel benzotriazole N-acylarylhydrazone hybrids was synthesized according fragment-based design strategy. All the synthesized compounds were evaluated for their anticancer activity against 60 human tumor cell lines by NCI (USA). Five compounds: 3d, 3e, 3f, 3o and 3q exhibited significant to potent anticancer activity at low concentrations. Compound 3q showed the most prominent broad-spectrum anticancer activity against 34 tumor cell lines, with mean growth inhibition percent of 45.80%. It exerted the highest potency against colon HT-29 cell line, with cell growth inhibition 86.86%. All leukemia cell lines were highly sensitive to compound 3q. Additionally, compound 3q demonstrated lethal activity to MDA-MB-435 belonging melanoma. Compound 3e exhibited the highest anticancer activity against leukemic CCRF-CEM and HL-60(TB) cell lines, with cell growth inhibition 86.69% and 86.42%, respectively. Moreover, it exerted marked potency against ovarian OVCAR-3 cancer cell line, with cell growth inhibition 78.24%. Four compounds: 3d, 3e, 3f and 3q were further studied through determination of IC₅₀ values against the most sensitive cancer cell lines. The four compounds exhibited highly potent anticancer activity against ovarian cancer OVCAR-3 and leukemia HL-60 (TB) cell lines, with IC₅₀ values in nano-molar range between 25 and 130 nM. They showed 18–2.3 folds more potent anticancer activity than doxorubicin. The most prominent compound was 3e, (IC₅₀ values 29 and 25 nM against OVCAR-3 and HL-60 (TB) cell lines, respectively), representing 10 and 18 folds more potency than doxorubicin. The anti-proliferative activity of these four compounds appeared to correlate well with their ability to inhibit FAK at nano-molar range between 44.6 and 80.75 nM. Compound 3e was a potent, inhibitor of FAK and Pyk2 activity with IC₅₀ values of 44.6 and 70.19 nM, respectively. It was 1.6 fold less potent for Pyk2 than FAK. Additionally, it displayed inhibition in cell based assay measuring phosphorylated-FAK (IC₅₀ = 32.72 nM). Inhibition of FAK enzyme led to a significant increase in the level of active caspase-3, compared to control (11.35 folds), accumulation of cells in pre-G1 phase and annexin-V and propidium iodide staining in addition to cell cycle arrest at G2/M phase indicating that cell death proceeded through an apoptotic mechanism.     

Design,synthesis and molecular modeling of new 4-phenylcoumarin derivatives as tubulin polymerization inhibitors targeting MCF-7 breast cancer cells

A new set of 4-phenylcoumarin derivatives was designed and synthesized aiming to introduce new tubulin polymerization inhibitors as anti-breast cancer candidates. All the target compounds were evaluated for their cytotoxic effects against MCF-7 cell line, where compounds 2f, 3a, 3b, 3f, 7a and 7b, showed higher cytotoxic effect (IC₅₀?=?4.3–21.2?μg/mL) than the reference drug doxorubicin (IC₅₀?=?26.1?μg/mL), additionally, compounds 1 and 6b exhibited the same potency as doxorubicin (IC₅₀?=?25.2 and 28.0?μg/mL, respectively). The thiazolidinone derivatives 3a, 3b and 3f with potent and selective anticancer effects towards MCF-7 cells (IC₅₀?=?11.1, 16.7 and 21.2?μg/mL) were further assessed for tubulin polymerization inhibition effects which showed that the three compounds were potent tubulin polymerization suppressors with IC₅₀ values of 9.37, 2.89 and 6.13?μM, respectively, compared to the reference drug colchicine (IC₅₀?=?6.93?μM). The mechanistic effects on cell cycle progression and induction of apoptosis in MCF-7 cells were determined for compound 3a due to its potent and selective cytotoxic effects in addition to its promising tubulin polymerization inhibition potency. The results revealed that compound 3a induced cell cycle cessation at G2/M phase and accumulation of cells in pre-G1 phase and prevented its mitotic cycle, in addition to its activation of caspase-7 mediating apoptosis of MCF-7 cells. Molecular modeling studies for compounds 3a, 3b and 3f were carried out on tubulin crystallography, the results indicated that the compounds showed binding mode similar to the co-crystalized ligand; colchicine. Moreover, pharmacophore constructed models and docking studies revealed that thiazolidinone, acetamide and coumarin moieties are crucial for the activity. Molecular dynamics (MD) studies were carried out for the three compounds over 100?ps. MD results of compound 3a showed that it reached the stable state after 30?ps which was in agreement with the calculated potential and kinetic energy of compound 3a.     

Synthesis,anticancer assessment on human breast,liver and colon carcinoma cell lines and molecular modeling study using novel pyrazolo[4,3-c]pyridine derivatives

The key intermediate 3-aminopyrazolo[4,3-c]pyridine-4,6-dione (2) is considered as a precursor for some novel pyrazolo[4,3-c]pyridines 4a-c, arylhydrazopyrazolo[4,3-c]pyridines 8a-e, pyrazolo[4,5,1-ij][1,6]naphthyridines 11a-e and pyrido[4′,3′:3,4]pyrazolo[1,5-a]-pyrimidines 15a-d through Knovenegal condensation, coupling reaction and Michael addition. Some of the newly synthesized pyrazolo[4,3-c]pyridine derivatives were investigated for anticancer activity. The results of the cytotoxic activity revealed that compound 6b was the most active compound against the breast and liver carcinoma cell lines which gives IC₅₀ values of 1.937 and 3.695 µg/mL, respectively compared to reference drug (doxorubicin) with IC₅₀ values of 2.527 and 4.749 µg/ml, respectively. Moreover, compound 6c was potent compound against the colon carcinoma cell line which gives the value of IC₅₀ = 2.914 µg/ml compared to doxorubicin with IC₅₀ value of 3.641 µg/ml. Some selected of the novel synthesized compounds were docked inside the active site of ERK2 enzyme and were found display a suitable binding with the active site amino acids according to their bond lengths, angles and conformational energy.     

Synthesis,biological activities,and docking studies of d-pantolactone derivatives as novel FAS inhibitors

A novel series of fatty acid synthase (FAS) inhibitors with D-(−)-pantolactone moiety and potential utility for the treatment of obesity were designed, synthesized and characterized, in which the structure of compound 3k was further confirmed by single X-ray diffraction. The mouse FAS inhibitory activity of synthesized compounds was evaluated. Major synthesized compounds (except 3g, 3i, 3k, 3l, and 3n) exhibited moderate FAS inhibitory properties with IC₅₀ values in the range of 13.68 ± 1.52–33.19 ± 1.39 μM, reference inhibitor C75 has IC₅₀ value of 13.86 ± 2.79 μM. Eight compounds (3c, 3d, 3e, 3f, 3j, 3m, 3q and 3r) also displayed inhibitory effect on lipid accumulation in human HepG2 cells. Additionally, the molecular docking study revealed that compound 3m having good inhibition activity against FAS and lipid accumulation also showed promising binding affinities with hFAS, while its binding model with hFAS (PDB ID: 4PIV) was different from that of reference compound C75.     

Design,synthesis and biological evaluation of novel thieno[3,2-d]pyrimidine and quinazoline derivatives as potent antitumor agents

Four series of novel thieno[3,2-d]pyrimidine and quinazoline derivatives containing N-acylhydrazone or semicarbazone were designed, synthesized, and evaluated for their biological activity. Of which compound 14 showed the most potent antitumor activities with IC₅₀ values of 1.78 μM, 1.02 μM, 1.98 μM, 0.41 μM and 0.22 μM against HT-29, MDA-MB-231, U87MG, PC-3 and HCT-116 cell lines respectively. Inhibition of enzymatic assays showed that PI3Kα was very likely to be one of the drug targets of 14 with the IC₅₀ value of 0.20 μM. According to the results of antitumor activity, the SARs were summarized, which indicated that thieno[3,2-d]pyrimidine and semicarbazone are optimal fragments. In addition, compounds with hydroxyl group at the 4-position on the terminal phenyl ring were more active. Annexin-V and propidium iodide (PI) double staining confirmed that the most active cytotoxic compound 14 can induce cell apoptosis in HCT-116 cells. Moreover, the influence of 14 on the cell cycle distribution was assessed on the HCT-116 cell line, exhibiting a cell cycle arrest at the G2/M phase. Furthermore, molecular docking analysis was also performed to determine possible binding modes between PI3Kα and the target compound. These results will guide us to further refine the structure of the thieno[3,2-d]pyrimidine and quinazoline derivatives to achieve optimal antitumor activity.     

Synthesis,bioactivity and molecular modeling studies on potential anti-Alzheimer piperidinehydrazide-hydrazones

A group of N-benzylpiperidine-3/4-carbohydrazide-hydrazones were designed, synthesized and evaluated for acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) activities, Aβ₄₂ self-aggregation inhibitory potentials, and antioxidant capacities, in vitro. All of the compounds displayed eeAChE and huAChE inhibitory activity in a range of IC₅₀ = 5.68–11.35 µM and IC₅₀ = 8.80–74.40 µM, respectively and most of the compounds exhibited good to moderate inhibitory activity on BuChE enzyme. Kinetic analysis and molecular modeling studies were also performed for the most potent compounds (1g and 1j). Not only the molecular modeling studies but also the kinetic analysis suggested that these compounds might be able to interact with the catalytic active site (CAS) and the peripheral anionic site (PAS) of the enzymes. In the light of the results, compound 1g and compound 1j may be suggested as lead compounds for multifunctional therapy of AD.     

New thiazol-hydrazono-coumarin hybrids targeting human cervical cancer cells: Synthesis,CDK2 inhibition,QSAR and molecular docking studies

Motivated by the potential anticancer activity of both coumarin and 2-aminothiazole nuclei, a new set of thiazol-2-yl hydrazono-chromen-2-one analogs were efficiently synthesized aiming to obtain novel hybrids with potential cytotoxic activity. MTT assay investigated the significant potency of all the target compounds against the human cervical cancer cell lines (HeLa cells). Cell cycle analysis showed that the representative compound 8a led to cell cycle cessation at G0/G1 phase indicating that CDK2/E1complex could be the plausible biological target for these newly synthesized compounds. Thus, the most active compounds (7c and 8a-c) were tested for their CDK2 inhibitory activity. The biological results revealed their significant CDK2 inhibitory activity with IC₅₀ range of 0.022–1.629 nM. Moreover, RT-PCR gene expression assay showed that compound 8a increased the levels of the nuclear CDK2 regulators P21 and P27 by 2.30 and 5.7 folds, respectively. ELISA tequnique showed also that compound 8a led to remarkable activation of caspases-9 and -3 inducing cell apoptosis. QSAR study showed that the charge distribution and molecular hydrophobicity are the structural features affecting cytotoxic activity in this series. Molecular docking study for the most potent cytotoxic compounds (7c and 8a-c) rationalized their superior CDK2 inhibitory activity through their hydrogen bonding and hydrophobic interactions with the key amino acids in the CDK2 binding site. Pharmacokinetic properties prediction of the most potent compounds showed that the newly synthesized compounds are not only with promising antitumor activity but also possess promising pharmacokinetic properties.     

Synthesis of novel 1,2-bis-quinolinyl-1,4-naphthoquinones: ERK2 inhibition,cytotoxicity and molecular docking studies

Two novel series of N-2,3-bis(6-substituted-4-hydroxy-2-oxo-1,2-dihydroquinolin-3-yl)naphthalene-1,4-diones 3a-d and substituted N-(methyl/ethyl)bisquinolinone triethyl-ammonium salts 4e,f were successfully synthesized. The synthesized compounds were targeted as new candidates to extracellular signal-regulated kinases 1/2 (ERK1/2) with considerable antineoplastic activity. The synthesis involved the reactions of 2 equivalents of 4-hydroxy-2(1H)-quinolinones 1a-f and one equivalent of 1,4-naphthoquinone (2) in a mixture of ethanol/dimethylformamide (1:1) as a solvent and 0.5 mL Et₃N. In the reaction of 6-methyl-4-hydroxyquinolone 1b with 2, a side product 4b of the second series was obtained. In general, the presence of free NH-quinolone gave a single compound of the first series, whereas reaction of N-methyl/ethyl-quinolones 1e,f with 2 enhanced the formation of compounds of the second series. The structures of the new compounds were proved by different spectroscopic techniques such as IR, NMR (2D-NMR) and mass spectra, elemental analysis, and X-ray crystallography. To further elucidate the mechanism of action of these newly synthesized compounds, compounds 3a, 3b, 4e and 4f were selected to investigate for their MAP Kinases pathway inhibition together with molecular docking using ATP-binding site of ERK2. The results revealed that compounds 3a, 3b and 4f inhibited ETS-1 phosphorylation by ERK2 in a dose dependent manner. Also, compound 4f showed highest potency for ERK2 inhibition with ATP-competitive inhibition mechanism which was confirmed by the formation of three hydrogen bond in the molecular docking studies. The synthesized compounds were then tested for their in vitro anticancer activity against the NCI-60 panel of tumor cell lines. Interestingly, the selected compounds displayed from modest to strong cytotoxic activities. Compound 3b demonstrated broad spectrum anti-tumor activity against the nine tumor sub-panels tested, while compound 3d proved to be lethal to most of the cancer cell lines as shown by their promising GI₅₀ and TGI values in NCI in vitro five dose testing. These results revealed that the synthesized compounds can potentially serve as leads for the development of novel chemotherapeutic agents and structure improvement will be necessary for some derivatives for enhancing their cellular activities and pharmacokinetic profile.