The discovery of 2,5-isomers of triazole-pyrrolopyrimidine as selective Janus kinase 2 (JAK2) inhibitors versus JAK1 and JAK3

Design, synthesis, in vitro anticancer, molecular docking and SAR studies of new series of pyrrolo[2,3-d]pyrimidine derivatives

The current study involves the design and synthesis of a newly synthesized pyrrolo[2,3-d]pyrimidine derivatives to contain chlorine atoms in positions 4 and 6 and trichloromethyl group in position 2 using microwave technique as a new and robust approach for preparation of this type of pyrrolo[2,3-d]pyrimidine derivatives. The chemical structure of the synthesized pyrrolo[2,3-d]pyrimidine derivatives 3-19 was well-characterized using spectral and elemental analyses as well as single-crystal X-ray diffraction. All compounds were tested in vitro against seven selected human cancer cell lines, namely, MCF7, A549, HCT116, PC3, HePG2, PACA2 and BJ1 using MTT assay. It was found that compounds 14a, 16b and 18b were the most active toward MCF7 with IC50 (1.7, 5.7, and 3.4 μg/ml, respectively) relative to doxorubicin (Dox.) (26.1 μg/ml). Additionally, compound 17 exerted promising cytotoxic effects against HePG2 and PACA2 with IC50 (8.7 and 6.4 μg/ml, respectively) relative to Dox. (21.6 and 28.3 μg/ml, respectively). The molecular docking study confirmed our ELISA result which showed the promising binding affinities of compounds 14a and 17 against Bcl2 anti-apoptotic protein. At the gene expression level, P53, BAX, DR4 and DR5 were up-regulated, while Bcl2, Il-8, and CDK4 were down-regulated in 14a, 14b and 18b treated MCF7 cells. At the protein level, compound 14b increased the activity of Caspase 8 and BAX (18.263 and 14.25 pg/ml) relative to Dox. (3.99 and 4.92 pg/ml, respectively), while the activity of Bcl2 was greatly decreased in 14a treated MCF7 (2.4 pg/ml) compared with Dox. (14.37 pg/ml). Compounds 14a and 14b caused cell cycle arrest at the G1/S phase in MCF7. Compounds 16b and 18b induced the apoptotic death of MCF7 cells. In addition, the percentage of fragmented DNA was increased significantly in 14a treated MCF7 cells.

Synthesis and structure-activity relationship studies of 1,5-isomers of triazole-pyrrolopyrimidine as selective Janus kinase 1 (JAK1) inhibitors

JAK inhibitors have been considered as useful targets for the treatment of related diseases. However, first-generation JAK inhibitors have side effects such as anemia, thrombocytopenia, neutropenia and headaches which have been suggested to result from high JAK2 inhibition. Second-generation JAK inhibitors with more specific JAK isozyme inhibition have been studied to eliminate these adverse effects. In this study, novel 4-(1,5- or 2,5-triazole)-pyrrolopyrimidine derivatives with aromatic moieties were synthesized as JAK1 inhibitors, and an in vitro enzyme assay was used to evaluate the JAK inhibitory effects. Among these JAK1 inhibitors, the compound 23a showed an IC₅₀ level of 72 nM, as well as being selective against other JAKs by 12 times or more: the results of molecular docking studies suggested that the high JAK1 selectivity resulted from a key interaction between the iodine atom of compound 23a and His-885 of hJAK1.

1,2,3-Triazole-Containing Compounds as Anti-Lung Cancer Agents: Current Developments, Mechanisms of Action, and Structure-Activity Relationship

Lung cancer is the most common malignancy and leads to around one-quarter of all cancer deaths. Great advances have been achieved in the treatment of lung cancer with novel anticancer agents and improved technology. However, morbidity and mortality rates remain extremely high, calling for an urgent need to develop novel anti-lung cancer agents. 1,2,3-Triazole could be readily interact with diverse enzymes and receptors in organisms through weak interaction. 1,2,3-Triazole can not only be acted as a linker to tether different pharmacophores but also serve as a pharmacophore. This review aims to summarize the recent advances in 1,2,3-triazole-containing compounds with anti-lung cancer potential, and their structure-activity relationship (SAR) together with mechanisms of action is also discussed to pave the way for the further rational development of novel anti-lung cancer candidates.

Novel Bis- and Mono-Pyrrolo[2,3-d]pyrimidine and Purine Derivatives: Synthesis, Computational Analysis and Antiproliferative Evaluation

Novel symmetrical bis-pyrrolo[2,3-d]pyrimidines and bis-purines and their monomers were synthesized and evaluated for their antiproliferative activity in human lung adenocarcinoma (A549), cervical carcinoma (HeLa), ductal pancreatic adenocarcinoma (CFPAC-1) and metastatic colorectal adenocarcinoma (SW620) cells. The use of ultrasound irradiation as alternative energy input in Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) shortened the reaction time, increased the reaction efficiency and led to the formation of exclusively symmetric bis-heterocycles. DFT calculations showed that triazole formation is exceedingly exergonic and confirmed that the presence of Cu(I) ions is required to overcome high kinetic requirements and allow the reaction to proceed. The influence of various linkers and 6-substituted purine and regioisomeric 7-deazapurine on their cytostatic activity was revealed. Among all the evaluated compounds, the 4-chloropyrrolo[2,3-d]pyrimidine monomer 5f with 4,4′-bis(oxymethylene)biphenyl had the most pronounced, although not selective, growth-inhibitory effect on pancreatic adenocarcinoma (CFPAC-1) cells (IC₅₀ = 0.79 µM). Annexin V assay results revealed that its strong growth inhibitory activity against CFPAC-1 cells could be associated with induction of apoptosis and primary necrosis. Further structural optimization of bis-chloropyrrolo[2,3-d]pyrimidine with aromatic linker is required to develop novel efficient and non-toxic agent against pancreatic cancer.

NO-releasing STAT3 inhibitors suppress BRAF-mutant melanoma growth

Constitutive activation of STAT3 can play a vital role in the development of melanoma. STAT3-targeted therapeutics are reported to show efficacy in melanomas harboring the BRAFV600E mutant and also in vemurafenib-resistant melanomas. We designed and synthesized a series of substituted nitric oxide (NO)-releasing quinolone-1,2,4-triazole/oxime hybrids, hypothesizing that the introduction of a STAT3 binding scaffold would augment their cytotoxicity. All the hybrids tested showed a comparable level of in vitro NO production. 7b and 7c exhibited direct binding to the STAT3-SH domain with IC₅₀ of ∼ 0.5 μM. Also, they abrogated STAT3 tyrosine phosphorylation in several cancer cell lines, including the A375 melanoma cell line that carries the BRAFV600E mutation. At the same time, they did not affect the phosphorylation of upstream kinases or other STAT isoforms. 7c inhibited STAT3 nuclear translocation in mouse embryonic fibroblast while 7b and 7c inhibited STAT3 DNA-binding activity in the A375 cell line. Their anti-proliferating activity is attributed to their ability to trigger the production of reactive oxygen species and induce G1 cell cycle arrest in the A375 cell line. Interestingly, 7b and 7c showed robust cell growth suppression and apoptosis induction in two pairs of BRAF inhibitor-naïve (-S) and resistant (-R) melanoma cell lines containing a BRAF V600E mutation. Surprisingly, MEL1617-R cells that are known to be more resistance to MEK inhibition by GSK1120212 than MEL1617-S cells exhibit a similar response to 7b and 7c.

1,2,3-Triazole-containing hybrids as potential anticancer agents: Current developments, action mechanisms and structure-activity relationships

Anticancer agents are critical for the cancer treatment, but side effects and the drug resistance associated with the currently used anticancer agents create an urgent need to explore novel drugs with low side effects and high efficacy. 1,2,3-Triazole is privileged building block in the discovery of new anticancer agents, and some of its derivatives have already been applied in clinics or under clinical trials for fighting against cancers. Hybrid molecules occupy an important position in cancer control, and hybridization of 1,2,3-triazole framework with other anticancer pharmacophores may provide valuable therapeutic intervention for the treatment of cancer, especially drug-resistant cancer. This review emphasizes the recent advances in 1,2,3-triazole-containing hybrids with anticancer potential, covering articles published between 2015 and 2019, and the structure-activity relationships, together with mechanisms of action are also discussed.

An Update on JAK Inhibitors

Janus kinases (JAKs) are a family of non-receptor tyrosine kinases, composed by four members, JAK1, JAK2, JAK3 and TYK2. JAKs are involved in different inflammatory and autoimmune diseases, as well as in malignancies, through the activation of the JAK/STAT signalling pathway. Furthermore, the V617F mutation in JAK2 was identified in patients affected by myeloproliferative neoplasms. This knowledge prompted researchers from academia and pharmaceutical companies to investigate this field in order to discover small molecule JAK inhibitors. These efforts recently afforded to the market approval of four JAK inhibitors. Despite the fact that all these drugs are pyrrolo[2,3-d]pyrimidine derivatives, many compounds endowed with different heterocyclic scaffolds have been reported in the literature as selective or multi-JAK inhibitors, and a number of them is currently being evaluated in clinical trials. In this review we will report many representative compounds that have been published in articles or patents in the last five years (period 2013-2017). The inhibitors will be classified on the basis of their chemical structure, focusing, when possible, on their structure activity relationships, selectivity and biological activity. For every class of derivatives, compounds disclosed before 2013 that have entered clinical trials will also be briefly reported, to underline the importance of a particular chemical scaffold in the search for new inhibitors.

Pyrrolopyrimidines: An update on recent advancements in their medicinal attributes

Fused heterocycles are reported to demonstrate variety of biological activities such as anticancer, antibacterial, antifungal and anti-inflammatory, and are thus exhaustively utilized in the field of medicinal chemistry. Pyrrolopyrimidines is one of the major classes of fused heterocycles which are extensively reported throughout the literature. Several reports suggest that pyrrolopyrimidine as fused scaffold possess more diverse and potent pharmacological profile than individual pyrrole and pyrimidine nucleus. Different pathological targets require different structural attributes reflected via varied substitutions, thus in recent years, researchers have employed various synthetic strategies to achieve desired substitutions on the pyrrolopyrimidine nucleus. In this review, authors highlight the recent advancement in this area, special focus was laid on the pharmacological profile and structure-activity relationship studies (SAR) of various synthesized pyrrolopyrimidine derivatives.