Synthesis and cytotoxicity of 3,4-disubstituted-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazoles and novel 5,6-dihydro-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives bearing 3,4,5-trimethoxyphenyl moiety

Secosteroid thiosemicarbazides and secosteroid-1,2,4-triazoles as antiproliferative agents targeting breast cancer cells: Synthesis and biological evaluation

A convenient and selective approach to 13,17-secoestra-1,3,5(10)-trien-17-oic acid [N'-arylcarbothioamido]hydrazides and hybrid molecules containing secosteroid and 1,2,4-triazole fragments was disclosed and these novel types of secosteroids were screened for cytotoxicity against hormone-dependent human breast cancer cell line MCF-7. Most of secosteroid-1,2,4-triazole hybrids showed significant cytotoxic effect comparable or superior to that of the reference drug cisplatin. Hit secosteroid-1,2,4-triazole hybrids 4b and 4h were characterized by high cytotoxicity and good selectivity towards MCF-7 breast cancer cells. PARP cleavage (marker of apoptosis) and ERα and cyclin D1 downregulation were discovered in MCF-7 cells treated with lead secosteroid-1,2,4-triazole hybrid 4b. The synthesized secosteroids may be considered as new promising anticancer agents.

Design, Synthesis, and Biological Evaluation of Novel Triazolothiadiazoles Derived From NSAIDs as Anticancer Agents

BACKGROUND

Although transplantation, surgical resection, and tumor ablation are treatment options available following early diagnosis of HCC, their efficacy is restricted due to poor prognosis and high recurrence rates. Hence, small molecules with high selectivity and bioactivity are urgently required.

OBJECTIVE

This study presents the synthesis of a series of new triazolothiadiazole derivatives (1a-3j) with NSAID moieties and their cytotoxic bioactivities.

METHODS

The new synthetic derivatives (1-3; 1a-3j) and NSAIDs ibuprofen, naproxen, and flurbiprofen that commonly used in clinics were screened against human liver (Huh7), breast (MCF7), and colon (HCT116) carcinoma cell lines under in vitro conditions via NCI-sulforhodamine B assay.

RESULTS

The 4-methoxyphenyl substituted condensed derivatives 1h, 2h, and 3h were the most active compounds. Based on its high potency, compound 3h was selected for the further biological evaluation of hepatocellular carcinoma cell lines, and the mechanisms underlying cell death induced by 3h were determined. The results revealed that compound 3h induced apoptosis and cell cycle arrest in the sub G1 phase in human liver cancer cells.

CONCLUSION

These new small molecules may be used for the development of new lead compounds.

Development of adamantane scaffold containing 1,3,4-thiadiazole derivatives: Design, synthesis, anti-proliferative activity and molecular docking study targeting EGFR

A new series of 1,3,4-thiadiazolo-adamantane derivatives were synthesized through molecular hybridization approach, then used as starting material to synthesize chloro and cyano acetamide-thiadiazole derivatives 2, 3. The newly designed compounds 1-3 were treated with different reagents to design 5-adamantyl thiadiazole derivatives 4-17 and evaluate their in vitro anti-proliferative activity against three cancer cell lines (MCF-7, HepG-2 and A549). Doxorubicin was used as a positive control. The most promising compounds 5, 6, 10a, 10b, 14b, 14c, and 17 showed up-regulation for BAX and down-regulation of Bcl-2, these findings proved their role as hopeful apoptotic inducers. In addition, the inhibitory activity against both wild EGFR^WT and mutant EGFR^L858R-TK for these derivatives revealed that compounds 5, 14c, and 17 have IC₅₀ value ranging from 85 nM to 71.5 nM against wild EGFR^WT and 37.85-41.19 nM against the mutant type, Lapatinib was used as a reference standard with IC₅₀ values of 31.8 nM and 39.53 nM, respectively. The most potent derivatives were subjected to further evaluation against double mutant EGFR ^L858R/T790M and showed good IC₅₀ values between (0.27-0.78 nM) compared to Lapatinib (0.18 nM) and Erlotinib (0.21 nM). Among them, thiazolo-thiadiazole adamantane derivative 17 exhibited the strongest inhibitory activity to the EGFR. Molecular docking studies were performed inside the active site of EGFR (1M17), and binding energy scores ranged between (-19.19 to -22.07 Kcal/mol) compared to Erlotinib (-19.10 Kcal/mol). Furthermore, oral bioavailability beside some pharmacokinetics properties of these derivatives were also investigated in this research work.

An insight on medicinal attributes of 1,2,4-triazoles

The present review aims to summarize the pharmacological profile of 1,2,4-triazole, one of the emerging privileged scaffold, as antifungal, antibacterial, anticancer, anticonvulsant, antituberculosis, antiviral, antiparasitic, analgesic and anti-inflammatory agents, etc. along with structure-activity relationship. The comprehensive compilation of work carried out in the last decade on 1,2,4-triazole nucleus will provide inevitable scope for researchers for the advancement of novel potential drug candidates having better efficacy and selectivity.

Cell-based screen identifies a new potent and highly selective CK2 inhibitor for modulation of circadian rhythms and cancer cell growth

Compounds targeting the circadian clock have been identified as potential treatments for clock-related diseases, including cancer. Our cell-based phenotypic screen revealed uncharacterized clock-modulating compounds. Through affinity-based target deconvolution, we identified GO289, which strongly lengthened circadian period, as a potent and selective inhibitor of CK2. Phosphoproteomics identified multiple phosphorylation sites inhibited by GO289 on clock proteins, including PER2 S693. Furthermore, GO289 exhibited cell type-dependent inhibition of cancer cell growth that correlated with cellular clock function. The x-ray crystal structure of the CK2α-GO289 complex revealed critical interactions between GO289 and CK2-specific residues and no direct interaction of GO289 with the hinge region that is highly conserved among kinases. The discovery of GO289 provides a direct link between the circadian clock and cancer regulation and reveals unique design principles underlying kinase selectivity.

Design, synthesis and antiproliferative activity of novel substituted 2-amino-7,8-dihydropteridin-6(5H)-one derivatives

Based on our previous work, a series of novel 2-amino-7,8-dihydropteridin-6(5H)-one derivatives were designed and synthesized via a ring-closing strategy. Biological evaluation with four human cancer cell lines (BT549, T47D, MDA-MB-468, and MDA-MB-231) showed that most of these compounds possessed moderate to potent antiproliferative activities. The most promising compound 8-benzyl-2-(phenethylamino)-7,8-dihydropteridin-6(5H)-one (6q) possessing IC₅₀ values of 7.75, 6.37, and 10.73μM against MDA-MB-468, T47D, and BT549, respectively, which were 49, 11, and 8 folds more active than the positive control fluorouracil. Moreover, fluorescence-activated cell sorting analysis revealed that compound 6q displayed a significant effect on G1 cell-cycle arrest in a concentration-dependent manner in T47D cells. The initial structure-activity relationship studies indicated that linker-length of amine chain in C-2 position of pyrimidine ring played a crucial role in modulating the antitumor activity, which could be of help in the rational design of dihydropteridin-6(5H)-ones as novel anticancer drugs.

Efficient T3P® mediated synthesis, differential cytotoxicity and apoptosis induction by indolo-triazolo-thiadiazoles in human breast adenocarcinoma cells

The limited efficacy of marketed anticancer agents demands the design of novel target-specific hybrid molecules incorporating multiple bioactive pharmacores to combat cancer. In the present study, a one-pot simple and efficient T3P^® mediated procedure for the preparation of twelve new 3-(substituted- [1,2,4]triazolo[3,4-b] [1,3,4]thiadiazolo)-1H-indoles with short reaction times, easy workup procedure, good yields, and purity of products is described. Cytotoxicity assay (MTT), flow-cytometric univariate cell cycle analysis, Annexin V-FITC staining and DNA fragmentation for cell death mechanism suggested that compound 3d with chloro-substituted phenyl ring induced enhanced cytotoxicity by an apoptotic pathway with high differential toxicity to breast adenocarcinoma cells (MCF-7) when compared with normal human dermal fibroblast cells. Additionally, the interaction between the BH3 domain of anti-apoptotic proteins Bcl-2 and Bcl-xL with the pharmacophore 3d was examined by molecular docking simulations to assess its potential to induce apoptosis. The docking solutions were proposed to explain the observed selectivity of 3d to Bcl-xL protein. From the present findings, the lead compound, 3d exhibited better anticancer activity when related to the other synthesized molecules with specific action on MCF-7 cells and hence can be considered as a plausible candidate chemo-therapeutic agent, although this warrants further experimentation.

Design, synthesis, and biological evaluation of novel alkylsulfanyl-1,2,4-triazoles as cis-restricted combretastatin A-4 analogues

Thirty-two novel 3-alkylsulfanyl-1,2,4-triazole derivatives, designed as cis-restricted combretastatin A-4 analogues, were synthesized and evaluated for their antiproliferative activities. The results indicated that analogue 20 showed more potent antiproliferative activities against PC-3 cell lines than positive control CA-4. Particularly, the most promising compound 25 displayed 5-fold improvement compared to CA-4 in inhibiting HCT116 cell proliferation with IC₅₀ values of 1.15 μM. Further flow-activated cell sorting analysis revealed that compound 20 displayed a significant effect on G₂/M cell-cycle arrest in a dose-dependent manner in PC-3 cells. From this study, analogues 20 and 25 were the most potent anti-cancer agents in this structural class, and were considered lead compounds for further development as anti-cancer drugs.

Novel hybrids of drug with bioactive heterocycles for enhancing biological activity

A novel series of aceclofenac hybridised with 1,2,4-triazolo-[3,4-b]-1,3,4-thiadiazoles were designed using molecular hybridization approach and synthesised 6a-j. The structural integrity was confirmed by analytical methods. The hybrid molecules were subjected to in vitro cytotoxic studies against four human cancer cell lines PA-1, OAW-42, T47-D and MCF-7 by MTT assay method. The results indicate that the hybrid molecules bearing halogen on phenyl ring in 6th position of triazolo-thiadiazole exhibited significant cytotoxic activity. The test compounds were also screened for antifungal activity against two strains.

Design, synthesis and biological evaluation of novel 3-alkylsulfanyl-4-amino-1,2,4-triazole derivatives

Based on our previous work, a series of novel 3-alkylsulfanyl-4-amino-1,2,4-triazole derivatives were designed, synthesized and evaluated for their antiproliferative activities. The results indicated that some compounds possessed significant antiproliferative activities against four cancer cell lines, HepG2, HCT116, PC-3, and Hela. Particularly, the most promising compound 8d displayed 184-, 18-, and 17-fold improvement compared to fluorouracil in inhibiting HCT116, Hela and PC-3 cell proliferation with IC50 values of 0.37, 2.94, and 31.31μM, respectively. Most interestingly, the compound did not affect the normal human embryonic kidney cells, HEK-293. Moreover, mechanistic investigation showed that the representative compound 8d induced apoptosis and blocked cell cycle in G2/M phase in Hela cells in a dose-dependent manner. These findings suggest that compound 8d may have potential to be developed as a promising lead for the design of novel anticancer small-molecule drugs.

Synthesis and Biological Activities of Some Novel (E)-Alpha-(methoxyimino)benzeneacetate Derivatives with Modified 1,2,4-Triazole Moiety

To find new strobilurin analogues with high activity against resistant pathogens, a series of (E)-α-(methoxyimino)benzeneacetate derivatives containing 1,2,4-triazole Schiff base side chain were designed and synthesized. Their structures were confirmed by IR,1H NMR, and13C NMR, ESI-HRMS, or elemental analyses. Bioassays indicated that most of the target compounds showed moderate to good fungicidal activities againstRhizoctonia solani,Botrytis cinerea Pers.,Fusarium graminearum,Cotton rhizoctoniosis, andBlumeria graminis. For example, compounds6gand6jexhibited promising antifungal activity againstRhizoctonia solani,Botrytis cinerea Pers.,andFusarium graminearum. Compounds6c,6l, and6mhad higher fungicidal activities againstBlumeria graminisat the concentration of 50 µg/mL; inhibitory rate is 91.41%, 92.13%, and 91.77%, respectively.