Structure-based development of novel triazoles and related thiazolotriazoles as anticancer agents and Cdc25A/B phosphatase inhibitors. Synthesis, in vitro biological evaluation, molecular docking and in silico ADME-T studies

Identification of new 5-(2,6-dichlorophenyl)-3-oxo-2,3-dihydro-5H-thiazolo[3,2-a]pyrimidine-7-carboxylic acids as p38α MAPK inhibitors: Design, synthesis, antitumor evaluation, molecular docking and in silico studies

In pursuit of discovering novel scaffolds that demonstrate potential inhibitory activity against p38α MAPK and possess strong antitumor effects, we herein report the design and synthesis of new series of 17 final target 5-(2,6-dichlorophenyl)-3-oxo-2,3-dihydro-5H-thiazolo[3,2-a]pyrimidine-7-carboxylic acids (4-20). Chemical characterization of the compounds was performed using FT-IR, NMR, elemental analyses and mass spectra of some representative examples. With many compounds showing potential inhibitory activity against p38α MAPK, two derivatives, 8 and 9, demonstrated the highest activity (>70 % inhibition) among the series. Derivative 9 displayed IC50 value nearly 2.5 folds more potent than 8. As anticipated, they both showed explicit interactions inside the kinase active site with the key binding amino acid residues. Screening both compounds for cytotoxic effects, they exhibited strong antitumor activities against lung (A549), breast (MCF-7 and MDA MB-231), colon (HCT-116) and liver (Hep-G2) cancers more potent than reference 5-FU. Their noticeable strong antitumor activity pointed out to the possibility of an augmented DNA binding mechanism of antitumor action besides their kinase inhibition. Both 8 and 9 exhibited strong ctDNA damaging effects in nanomolar range. Further mechanistic antitumor studies revealed ability of compounds 8 and 9 to arrest cell cycle in MCF-7 cells at S phase, while in HCT-116 treated cells at G0-G1 and G2/M phases. They also displayed apoptotic induction effects in both MCF-7 and HCT-116 with total cell deaths more than control untreated cells in reference to 5-FU. Finally, the compounds were tested for their anti-migratory potential utilizing wound healing assay. They induced a significant decrease in wound closure percentage after 24 h treatment in the examined cancer cells when compared to untreated control MCF-7 and HCT-116 cells better than 5-FU. In silico computation of physicochemical parameters revealed the drug-like properties of 8 and 9 with no violation to Lipinski's rule of five as well as their tolerable ADMET parameters, thus suggesting their utilization as potential future drug leads amenable for further optimization and development.

Thiazolotriazoles As Anti-infectives: Design, Synthesis, Biological Evaluation and In Silico Studies

The rational design of novel thiazolo[2,3-c][1,2,4]triazole derivatives was carried out based on previously identified antitubercular hit molecule H127 for discovering potent compounds showing antimicrobial activity. The designed compounds were screened for their binding efficacies against the antibacterial drug target enoyl-[acyl-carrier-protein] reductase, followed by prediction of drug-likeness and ADME properties. The designed analogues were chemically synthesized, characterized by spectroscopic techniques, followed by evaluation of antimicrobial activity against bacterial and fungal strains, as well as antitubercular activity against M. tuberculosis and M. bovis strains. Among the synthesized compounds, five compounds, 10, 11, 35, 37 and 38, revealed antimicrobial activity, albeit with differential potency against various microbial strains. Compounds 10 and 37 were the most active against S. mutans (MIC: 8 μg/mL), while compounds 11 and 37 showed the highest activity against B. subtillis (MIC: 16 μg/mL), whereas compounds 10, 11 and 37 displayed activities against E. coli (MIC: 16 μg/mL). Meanwhile, compounds 10 and 35 depicted activities against S. typhi (MIC: 16 μg/mL) and compound 10 showed antifungal activity against C. albicans (MIC: 32 μg/mL). The current study has identified two broad-spectrum antibacterial hit compounds (10 and 37). Further structural investigation on these molecules is underway to enhance their potency.

The Role of Pyrazolo[3,4-d]pyrimidine-Based Kinase Inhibitors in The Attenuation of CCl4-Induced Liver Fibrosis in Rats

Liver Fibrosis can be life-threatening if left untreated as it may lead to serious, incurable complications. The common therapeutic approach is to reverse the fibrosis while the intervention is still applicable. Celecoxib was shown to exhibit some antifibrotic properties in the induced fibrotic liver in rats. The present study aimed to investigate the possible antifibrotic properties in CCl4-induced liver fibrosis in male Sprague–Dawley rats compared to celecoxib of three novel methoxylated pyrazolo[3,4-d]pyrimidines. The three newly synthesized compounds were proved to be safe candidates. They showed a therapeutic effect against severe CCl4-induced fibrosis but at different degrees. The three compounds were able to partially reverse hepatic architectural distortion and reduce the fibrotic severity by showing antioxidant properties reducing MDA with increasing GSH and SOD levels, remodeling the extracellular matrix proteins and liver enzymes balance, and reducing the level of proinflammatory (TNF-α and IL-6) and profibrogenic (TGF-β) cytokines. The results revealed that the dimethoxy-analog exhibited the greatest activity in all the previously mentioned parameters compared to celecoxib and the other two analogs which could be attributed to the different methoxylation patterns of the derivatives. Collectively, the dimethoxy-derivative could be considered a safe promising antifibrotic candidate.

Thioethers: An Overview

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Spreading rapidly in recent years, cancer has become one of the causes of the highest mor-tality rates after cardiovascular diseases. The reason for cancer development is still not clearly under-stood despite enormous research activities in this area. Scientists are now working on the biology of cancer, especially on the root cause of cancer development. The aim is to treat the cancer disease and thus cure the patients. The continuing efforts for the development of novel molecules as potential anti-cancer agents are essential for this purpose. The main aim of this review was to present a survey on the medicinal chemistry of thioethers and provide practical data on their cytotoxicities against various cancer cell lines. The research articles published between 2001-2020 were consulted to pre-pare this review article; however, patent literature has not been included. The thioether-containing heterocyclic compounds may emerge as a new class of potent and effective anti-cancer agents in the future.

Discovery of potent and selective Cdc25 phosphatase inhibitors via rapid assembly and in situ screening of Quinonoid-focused libraries

Cell division cycle 25 (Cdc25) phosphatase is an attractive target for drug discovery. The rapid assembly and in situ screening of focused combinatorial fragment libraries using efficient modular reactions is a highly robust strategy for discovering bioactive molecules. In this study, we have utilized miniaturized synthesis to generate several quinonoid-focused libraries, by standard CuAAC reaction and HBTU-based amide coupling chemistry. Then the enzyme inhibition screening afforded some potent and selective Cdc25s inhibitors. Compound M5N36 (Cdc25A: IC₅₀ = 0.15 ± 0.05 μM; Cdc25B: IC₅₀ = 0.19 ± 0.06 μM; Cdc25C: IC₅₀ = 0.06 ± 0.04 μM) exhibited higher inhibitory activity than the initial lead NSC663284 (Cdc25A: IC₅₀ = 0.27 ± 0.02 μM; Cdc25B: IC₅₀ = 0.42 ± 0.01 μM; Cdc25C: IC₅₀ = 0.23 ± 0.01 μM). Moreover, M5N36 displayed about three-fold more potent against Cdc25C than Cdc25A and B, indicating that M5N36 could act as a relatively selective Cdc25C inhibitor. Cell viability evaluation, western blotting and molecular simulations provided a mechanistic understanding of the activity of M5N36. It showed promising anti-growth activity against the MDA-MB-231 cell line and desirable predicted physicochemical properties. Overall, M5N36 was proven to be a promising novel Cdc25C inhibitor.

New pyrimidines and triazolopyrimidines as antiproliferative and antioxidants with cyclooxygenase-1/2 inhibitory potential

Aim: Cyclooxygenase-2 (COX-2) inhibition and scavenging-free radicals are important targets in cancer treatment. Materials & methods: Sulfanylpyrimidines and triazolopyrimidines were synthesized and evaluated as anticancer and antioxidant COX-1/2 inhibitors. Results: Compound 7 showed the same growth inhibitory activity as 5-fluorouracil against MCF-7. Compound 6f displayed broad-spectrum anticancer activity against the four tested cancer cell lines. Compounds 5b, 6a, 6c, 6d and 8 were found to be more active antioxidants than trolox. Compounds 6a, 6c, 6f and 8 revealed high COX-2 inhibitory activity and selectivity, which was confirmed by docking studies. Conclusion: Compound 6f could be considered as promising anticancer and antioxidant structural lead with COX-2 inhibition that deserve further derivatization and investigation.

Medicinal chemistry insights into novel CDC25 inhibitors

Cell division cycle 25 (CDC25) phosphatases, a kind of cell cycle regulators, have become an attractive target for drug discovery, as they have been found to be over-expressed in various human cancer cells. Several CDC25 inhibitors have achieved significant attention in clinical trials with possible mechanistic actions. Prompted by the significance of CDC25 inhibitors with medicinal chemistry prospect, it is an apt time to review the various drug discovery methods involved in CDC25 drug discovery including high throughput screening (HTS), virtual screening (VS), fragment-based drug design, substitution decorating approach, structural simplification approach and scaffold hopping method to seek trends and identify promising new avenues of CDC25 drug discovery.

Biological Activity and In Silico Study of 3-Modified Derivatives of Betulin and Betulinic Aldehyde

A series of 3-substituted derivatives of betulin and betulinic aldehyde were synthesized as promising anticancer agents. The newly triterpenes were tested against five human cancer cell lines like biphenotypic B myelomonocytic leukaemia (MV-4-11), adenocarcinoma (A549), prostate (Du-145), melanoma (Hs294T), breast adenocarcinoma (MCF-7) and normal human mammary gland (MCF-10A). The compound 9 showed towards Du-145, MCF-7 and Hs294T cells significant antiproliferative activity with IC₅₀ ranging from 7.3 to 10.6 μM. The evaluation of ADME properties of all compounds also includes their pharmacokinetic profile. The calculated TPSA values for synthetized derivatives are in the range between 43.38 Ų and 55.77 Ų suggesting high oral bioavailability. The molecular docking calculations showed that triterpene 9 fits the active site of the serine/threonine protein kinase Akt.

Therapeutic target discovery using Boolean network attractors: improvements of kali

In a previous article, an algorithm for identifying therapeutic targets in Boolean networks modelling pathological mechanisms was introduced. In the present article, the improvements made on this algorithm, named kali, are described. These improvements are (i) the possibility to work on asynchronous Boolean networks, (ii) a finer assessment of therapeutic targets and (iii) the possibility to use multivalued logic. kali assumes that the attractors of a dynamical system, such as a Boolean network, are associated with the phenotypes of the modelled biological system. Given a logic-based model of pathological mechanisms, kali searches for therapeutic targets able to reduce the reachability of the attractors associated with pathological phenotypes, thus reducing their likeliness. kali is illustrated on an example network and used on a biological case study. The case study is a published logic-based model of bladder tumorigenesis from which kali returns consistent results. However, like any computational tool, kali can predict but cannot replace human expertise: it is a supporting tool for coping with the complexity of biological systems in the field of drug discovery.