Modification of imidazothiazole derivatives gives promising activity in B-Raf kinase enzyme inhibition; synthesis, in vitro studies and molecular docking

Anticancer and anti-inflammatory effects of novel ethyl pyrazole derivatives having sulfonamide terminal moiety

In the present work, a new series of ethyl pyrazole-containing compounds with side sulphonamide moiety was designed and synthesized. The new derivatives were divided into four groups based on the linker between the sulphonamide and pyridine ring attached to position 4 of the pyrazole ring and the substitution on the phenyl ring at position 3 of the same ring. The linker could be ethyl or propyl linkers. The phenyl ring is substituted with a methoxy group or hydroxyl group at position 3. The aim compounds were tested for their JNK1, JNK2, JNK3, and BRAF(V600E) activities. Compounds 23b, 23c, and 23d showed the highest activity with nanomolar IC50s. The most potent compound over JNK1 was 23d with an IC502 nM. While compound 23c was the most potent over JNK2 with an IC5057 nM. Finally, compound 23b was the most potent over JNK2 and BRAF(V600E) with IC50s of125 nM and 98 nM, respectively. After obtaining kinase inhibitory activity, the compounds were submitted to NCI to test their activity over different cell lines. Compound 23b showed the highest activity over most tested cell lines. In the second part of the present study, the final target compounds were tested for their anti-inflammatory effect. The anti-inflammatory effect of the new final compounds was performed by measuring their ability to inhibit inducible nitric oxide release and prostaglandin E2 production inhibition. Compound 23c showed the highest activity regarding nitric oxide release with IC50 0.63 μM, while compound 21d had the highest activity regarding prostaglandin E2 production with IC50 0.52 μM. The effect of the most potent compounds was tested by western blot against iNOS, COX-1, and COX-2.

Recent development of azole-sulfonamide hybrids with the anticancer potential

Cancer exhibits heterogeneity that enables adaptability and remains grand challenges for effective treatment. Chemotherapy is a validated and critically important strategy for the treatment of cancer, but the emergence of multidrug resistance which may lead to recurrence of disease or even death is a major hurdle for successful chemotherapy. Azoles and sulfonamides are important anticancer pharmacophores, and azole-sulfonamide hybrids have the potential to simultaneously act on dual/multiple targets in cancer cells, holding great promise to overcome drug resistance. This review outlines the current scenario of azole-sulfonamide hybrids with the anticancer potential, and the structure-activity relationships as well as mechanisms of action are also discussed, covering articles published from 2020 onward.

Anti-inflammatory effect of 3-fluorophenyl pyrimidinylimidazo[2,1-b]thiazole derivatives as p38α inhibitors

In the present work, the anti-inflammatory effect of 30 compounds containing 3-fluorophenyl pyrimidinylimidazo[2,1-b]thiazole was investigated. All final target compounds showed significant Inhibitory effect on p38α. P38α is considered one of the key kinases in the inflammatory process due to its regulatory effect on pro-inflammatory mediators. The final target compounds divided into four group based on the type of terminal moiety (amide and sulfonamide) and the linker between pyrimidine ring and terminal moiety (ethyl and propyl). Most compounds with terminal sulfonamide moiety and propyl linker between the sulfonamide and pyrimidine ring were the most potent among all synthesized final target compounds with sub-micromolar IC50s. Compound 24g (with p-Cl benzene sulfonamide and propyl linker) exhibited the highest activity over P38α with IC50 0.68 µM. All final target compounds were tested for their ability to inhibit nitric oxide release and prostaglandin E2 production. Compounds having amide terminal moiety with ethyl linker showed higher inhibitory activity for nitric oxide release and compound 21d exhibited the highest activity for nitric oxide release with IC50 1.21 µM. Compounds with terminal sulfonamide moiety and propyl linker showed the highest activity for inhibiting PGE2 production and compounds 24i and 24g had the lowest IC50s with value 0.87 and 0.89 µM, respectively. Compounds 21d, 22d and 24g were tested for their ability to inhibit over expression of iNOS, COX1, and COX2. In addition the ability of compounds 21d, 22d and 24g to inhibit inflammatory cytokines were determined. Finally molecular docking of the three compounds were performed on P38α crystal structure to expect their mode of binding.

An updated literature on BRAF inhibitors (2018-2023)

BRAF is the most common serine-threonine protein kinase and regulates signal transduction from RAS to MEK inside the cell. The BRAF is a highly active isoform of RAF kinase. BRAF has two domains such as regulatory and kinase domains. The BRAF inhibitors bind in the c-terminus of the kinase domain and inhibit the downstream pathways. The mutation occurs mainly in the A-loop of the kinase domain. The mutation occurs due to a conversion of valine to glutamate/lysine/arginine/aspartic acid at 600th position. Among the diverse mutations, BRAF^V600E is the most common and responsible for numerous cancer such as melanoma, colorectal, ovarian, and thyroid cancer. Due to mutations in RAC1, loss of PTEN, NF1, CCND1, USP28-FBW7 complex, COT overexpression, and CCND1 amplification, the BRAF kinase enzyme developed resistance over the commercially available BRAF inhibitors. There is still unmute urgence for the development of BRAF inhibitors to overcome the persistent limitation such as resistance, mutation, and adverse effects of drugs. In the current study, we described the structure, activation, downstream signaling pathway, and mutation of BRAF. Our group also provided a detailed review of BRAF inhibitors from the last five years (2018-2023) highlighting the structure-activity relationship, mechanistic study, and molecular docking studies. We hope that the current analysis will be a useful resource for researchers and provide chemists a glimpse into the future as design and development of more effective and secure BRAF kinase inhibitors. The development of BRAF inhibitors to overcome the persistent limitation such as resistance, mutation, and adverse effects of drugs. In depth description about different heterocyclic scaffolds (quinoline, imidazole, pyridine, triazole, pyrrole etc.) as BRAF inhibitors from the last five years (2018-2023) highlighting the structure-activity relationship, mechanistic study, and molecular docking studies.

From Bench to Bedside: What Do We Know about Imidazothiazole Derivatives So Far?

Imidazothiazole derivatives are becoming increasingly important in therapeutic use due to their outstanding physiological activities. Recently, applying imidazothiazole as the core, researchers have synthesized a series of derivatives with biological effects such as antitumor, anti-infection, anti-inflammatory and antioxidant effects. In this review, we summarize the main pharmacological effects and pharmacological mechanisms of imidazothiazole derivates; the contents summarized herein are intended to advance the research and rational development of imidazothiazole-based drugs in the future.

Gaussian field-based 3D-QSAR and molecular simulation studies to design potent pyrimidine-sulfonamide hybrids as selective BRAFV600E inhibitors

The "RAS-RAF-MEK-ERK" pathway is an important signaling pathway in melanoma. BRAFV600E (70-90%) is the most common mutation in this pathway. BRAF inhibitors have four types of conformers: type I (αC-IN/DFG-IN), type II (αC-IN/DFG-OUT), type I1/2 (αC-OUT/DFG-IN), and type I/II (αC-OUT/DFG-OUT). First- and second-generation BRAF inhibitors show resistance to BRAFV600E and are ineffective against malignancies induced by dimer BRAF mutants causing 'paradoxical' activation. In the present study, we performed molecular modeling of pyrimidine-sulfonamide hybrids inhibitors using 3D-QSAR, molecular docking, and molecular dynamics simulations. Previous reports reveal the importance of pyrimidine and sulfonamide moieties in the development of BRAFV600E inhibitors. Analysis of 3D-QSAR models provided novel pyrimidine sulfonamide hybrid BRAFV600E inhibitors. The designed compounds share similarities with several structural moieties present in first- and second-generation BRAF inhibitors. A total library of 88 designed compounds was generated and molecular docking studies were performed with them. Four molecules (T109, T183, T160, and T126) were identified as hits and selected for detailed studies. Molecular dynamics simulations were performed at 900 ns and binding was calculated. Based on molecular docking and simulation studies, it was found that the designed compounds have better interactions with the core active site [the nucleotide (ADP or ATP) binding site, DFG motif, and the phospho-acceptor site (activation segment) of BRAFV600E protein than previous inhibitors. Similar to the FDA-approved BRAFV600E inhibitors the developed compounds have [αC-OUT/DFG-IN] conformation. Compounds T126, T160 and T183 interacted with DIF (Leu505), making them potentially useful against BRAFV600E resistance and malignancies induced by dimer BRAF mutants. The synthesis and biological evaluation of the designed molecules is in progress, which may lead to some potent BRAFV600E selective inhibitors.

Synthesis, Antibacterial Activity, and Action Mechanism of Novel Sulfonamides Containing Oxyacetal and Pyrimidine

Bacterial leaf blight (BLB) and bacterial leaf streak (BLS) are two serious bacterial diseases caused by Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas oryzae pv. oryzicola (Xoc), respectively. However, the control of these diseases by conventional pesticides remains challenging due to development of resistances. We aimed to address this pending problem and developed a series of novel pyrimidine sulfonamide derivatives. Structurally, title compounds bear a unique oxyacetal group, which has a proven immune-activating effect. Compound E35 designed based on the 3D-QSAR model was demonstrated as the optimal in vitro activity against Xoo and Xoc, with EC₅₀ values of 26.7 and 30.8 mg/L, respectively, which were higher than the positive controls bismerthiazol (29.9 and 32.7 mg/L) and thiodiazole copper (30.5 and 36.4 mg/L). On the prevention level, the biological activity test showed compound E35 had superior protective activity (43.7%) on BLS to thiodiazole copper (32.1%). The defense enzymes and proteomics results suggested that compound E35 could be a versatile candidate as it improved plant's resistance to disease.

New Potential Agents for Malignant Melanoma Treatment-Most Recent Studies 2020-2022

Malignant melanoma (MM) is the most lethal skin cancer. Despite a 4% reduction in mortality over the past few years, an increasing number of new diagnosed cases appear each year. Long-term therapy and the development of resistance to the drugs used drive the search for more and more new agents with anti-melanoma activity. This review focuses on the most recent synthesized anti-melanoma agents from 2020-2022. For selected agents, apart from the analysis of biological activity, the structure-activity relationship (SAR) is also discussed. To the best of our knowledge, the following literature review delivers the latest achievements in the field of new anti-melanoma agents.

Thiazole and Related Heterocyclic Systems as Anticancer Agents: A Review on Synthetic Strategies, Mechanisms of Action and SAR Studies

Background:

Cancer is the second leading cause of death throughout the world. Many anticancer drugs are commercially available, but lack of selectivity, target specificity, cytotoxicity and development of resistance lead to serious side effects. There have been several experiments going on to develop compounds with minor or no side effects.

Objective:

This review mainly emphasizes synthetic strategies, SAR studies, and mechanism of action for thiazole, benzothiazole, and imidazothiazole containing compounds as anticancer agents.

Methods:

Recent literature related to thiazole and thiazole-related derivatives endowed with encouraging anticancer potential is reviewed. This review emphasizes contemporary strategies used for the synthesis of thiazole and related derivatives, mechanistic targets, and comprehensive structural activity relationship studies to provide perspective into the rational design of high-efficiency thiazole-based anticancer drug candidates.

Results:

Exhaustive literature survey indicated that thiazole derivatives are associated with properties of inducing apoptosis and disturbing tubulin assembly. Thiazoles are also associated with the inhibition of NFkB/mTOR/PI3K/AkT and regulation of estrogen-mediated activity. Furthermore, thiazole derivatives have been found to modulate critical targets such as topoisomerase and HDAC.

Conclusion:

Thiazole derivatives seem to be quite competent and act through various mechanisms. Some of the thiazole derivatives, such as compounds 29, 40, 62, and 74a with IC50 values of 0.05 μM, 0.00042 μM, 0.18 μM, and 0.67 μM, respectively not only have anticancer activity but they also have lower toxicity and better absorption. Therefore, some other similar compounds could be investigated to aid in the development of anticancer pharmacophores.

Discovery of New Imidazo[2,1-b]thiazole Derivatives as Potent Pan-RAF Inhibitors with Promising In Vitro and In Vivo Anti-melanoma Activity

BRAF is an important component of MAPK cascade. Mutation of BRAF, in particular V600E, leads to hyperactivation of the MAPK pathway and uncontrolled cellular growth. Resistance to selective inhibitors of mutated BRAF is a major obstacle against treatment of many cancer types. In this work, a series of new (imidazo[2,1-b]thiazol-5-yl)pyrimidine derivatives possessing a terminal sulfonamide moiety were synthesized. Pan-RAF inhibitory effect of the new series was investigated, and structure-activity relationship is discussed. Antiproliferative activity of the target compounds was tested against the NCI-60 cell line panel. The most active compounds were further tested to obtain their IC₅₀ values against cancer cells. Compound 27c with terminal open chain sulfonamide and 38a with a cyclic sulfamide moiety showed the highest activity in enzymatic and cellular assay, and both compounds were able to inhibit phosphorylation of MEK and ERK. Compound 38a was selected for testing its in vivo activity against melanoma. Cellular and animal activities are reported.