Recent advances in nitrogen-containing heterocyclic compounds as receptor tyrosine kinase inhibitors for the treatment of cancer: Biological activity and structural activity relationship

Recent advances on anticancer activity of benzodiazine heterocycles through kinase inhibition

The benzodiazines (phthalazine, quinazoline, quinoxaline, and cinnoline) have emerged as attractive scaffolds for creating novel anticancer drugs. These nitrogen-containing heterocycles are intriguing because they have a variety of configurations and can change chemically, allowing us to tailor their pharmacokinetic and pharmacodynamic features. Numerous studies have found that derivatives of these compounds have potent anticancer properties via inhibiting topoisomerases, protein kinases, and receptor tyrosine kinases. These compounds impair critical processes that control cancer proliferation and survival. Most benzodiazine derivatives have achieved clinical success, demonstrating the heterocycles' therapeutic potential. The use of phthalazine, cinnoline, and quinazoline derivatives should open new avenues in developing better and more targeted cancer treatments. In this overview, we summarize recent advances in synthesizing these compounds and illustrate how they serve as promising chemotherapeutic agents. Therefore, current research organizes the latest information to provide a clearer picture of design strategies that boost efficacy and selectivity, allowing the identification of potential anticancer drug candidates down the line. This research study also highlights the need to establish heterocyclic derivatives as a promising source of new molecules for cancer treatment with improved efficacy and decreased effects.

Nitrogen-containing heterocyclic drug products approved by the FDA in 2023: Synthesis and biological activity

This article profiles 13 newly approved nitrogen-containing heterocyclic drugs by the U.S. Food and Drug Administration (FDA) in 2023. These drugs target a variety of therapeutic areas including proteinuria in patients with IgA nephropathy, migraine in adults, Rett syndrome, PI3Kδ syndrome, vasomotor symptoms, alopecia areata, acute myeloid leukemia, postpartum depression, myelofibrosis, and various cancer and tumor types. The molecular structures of these approved drugs feature common aromatic heterocyclic compounds such as pyrrole, imidazole, pyrazole, isoxazole, pyridine, and pyrimidine, as well as aliphatic heterocyclic compounds like caprolactam, piperazine, and piperidine. Some compounds also contain multiple heteroatoms like 1,2,4-thiadiazole and 1,2,4-triazole. The article provides a comprehensive overview of the bioactivity spectrum, medicinal chemistry discovery, and synthetic methods for each compound.

Synthesis, Evaluation and Docking Studies of Disubstituted N-Heterocyclic Derivatives as Anticancer Agents

Cancer is a chronic disease reported with alarming rates of mortalities every year. Herein, we reported the synthesis of nitrogen based novel heterocyclic disubstituted derivatives and evaluated them against L929 and A549 cell lines using MTT assay. Among all, 6a2 and 6c1 were significantly active against L929 with IC50 value of 2.61±9.58 and 2.64±8.97 μg/mL respectively. Compounds 6a2 and 6c1 were also active against A549 with IC50 value of 2.36±9.20 and 2.43±6.28 μg/mL respectively and were found to be more potent than the standard drug Doxorubicin. A molecular docking study of the active compounds was also done against EGFR, conferring good binding affinity and binding interactions. Further biological investigations may provide valuable insights towards exploring the therapeutic potential of the active compounds in future.

Design, Synthesis, and Biological Evaluation of 3-Amino-pyrazine-2-carboxamide Derivatives as Novel FGFR Inhibitors

FGFR has been considered a crucial oncogenic driver and promising target for cancer therapy. Herein, we reported the design and synthesis of 3-amino-N-(3,5-dihydroxyphenyl)-6-methylpyrazine-2-carboxamide derivatives as novel FGFR inhibitors. SAR exploration led to the identification of 18i as a pan-FGFR inhibitor with favorable in vitro activity against FGFR1-4. Moreover, 18i blocked the activation of FGFR and downstream signaling pathways at the submicromolar level and exhibited potent antitumor activity in multiple cancer cell lines with FGFR abnormalities. Molecular docking was performed to investigate the possible binding modes of 18i within the binding site of FGFR2. These results suggest that compound 18i is a promising candidate for further drug discovery.

In vivo evaluation of novel synthetic pyrazolones as CDK9 inhibitors with enhanced pharmacokinetic properties

Aim: The structural optimization of our recently reported CDK9 inhibitor to furnish novel aminopyrazolones and methylpyrazolones with improved pharmacokinetics.Materials & methods: The synthesis of the targeted compounds was accomplished via conventional, grinding and microwave-assisted processes. The cytotoxicity of them was assayed against three carcinomas.Results: Analogs 2, 4 and 6 showed significant cytotoxicity and selectivity toward all tested cells. They also displayed potent CDK9 inhibition. Compound 6 arrested MCF-7 cycle at G2/M phase by stimulating the apoptotic pathway. The in vivo biodistribution of radiolabeled compound 6 displayed a potent targeting capability of 131I in solid tumors.Conclusion: Entity 6 is a potent CDK9 inhibitor where 131I-compound 6 can be used as a significant radiopharmaceutical imaging tool for tumors.

Synthesis and biological evaluation of novel D-ring fused steroidal N(2)-substituted-1,2,3-triazoles

In this study, a series of 13 new D-ring fused steroidal N(2)-substituted-1,2,3-triazoles were synthesized, characterized and evaluated for their biological activities. The relative binding affinities of the synthesized compounds for the ligand-binding domains of estrogen receptors α and β, androgen receptor and glucocorticoid receptor demonstrated that androstane derivatives 3a and 3h and estratriene derivative 4e showed highly specific and strong binding affinity for estrogen receptor β, while 3b, 3e, 4a and 4b displayed high binding affinity for the glucocorticoid receptor. The synthesized compounds were tested for their ability to inhibit aldo-keto reductases 1C3 and 1C4 in vitro by monitoring NADPH consumption using fluorescence spectroscopy. The most potent aldo-keto reductase 1C3 inhibitors were compounds 3h (71.17%) and 3f (69.9%). Moreover, a molecular docking study was carried out for compounds 3f and 3h against aldo-keto reductase 1C3 and results showed that compounds 3h and 3f could bind in the same site and orientation as EM1404. However, polar atoms in the triazole group enable additional hydrogen bonding deeper in SP1 with Tyr319, Tyr216 and the NADP+ cofactor, which are not visible in the AKR1C3-EM1404 crystal structure. The synthesized compounds were screened for their anticancer activity against four cancer cell lines. Compound 3f demonstrated moderate toxic effects across various cancer types, while displaying lower toxicity towards the healthy cell line. In summary, our findings indicate that N(2)-substituted-1,2,3-triazoles are high-affinity ligands for estrogen receptor β and glucocorticoid receptor, inhibitors of aldo-keto reductase 1C3 enzyme, and exhibit antiproliferative effects against cancer cells, suggesting that they could serve as scaffolds for anticancer drug development.

Synthesis and Evaluation of Thiazolyl-indole-2-carboxamide Derivatives as Potent Multitarget Anticancer Agents

Cancer is a complex disease driven by the dysregulation of multiple signaling pathways and cellular processes. The development of compounds capable of exerting multitarget actions against these key pathways involved in cancer progression is a promising therapeutic approach. Here, a series of novel (E/Z)-N-(4-(2-(2-(substituted)hydrazineyl)-2-oxoethyl)thiazol-2-yl)-1H-indole-2-carboxamide derivatives (6a-6z) were designed, synthesized, and evaluated for their biological activity. Compounds 6e, 6i, 6q, 6v, 7a, and 7b exhibited exceptional cytotoxicity against various cancer cell lines, particularly 6i (IC50 = 6.10 ± 0.4 μM against MCF-7 cell lines) and 6v (IC50 = 6.49 ± 0.3 μM against MCF-7 cell lines). These potent compounds inhibited key protein kinases like EGFR, HER2, VEGFR-2, and CDK2, induced cell cycle arrest at the G2/M phase, and promoted apoptosis. Docking studies revealed improved binding affinity of 6i and 6v with target proteins compared to reference drugs. These findings highlight the promising potential of 6i and 6v as multitarget cancer therapeutics deserving further development.

Advances in Cancer Therapy: A Comprehensive Review of CDK and EGFR Inhibitors

Protein kinases have essential responsibilities in controlling several cellular processes, and their abnormal regulation is strongly related to the development of cancer. The implementation of protein kinase inhibitors has significantly transformed cancer therapy by modifying treatment strategies. These inhibitors have received substantial FDA clearance in recent decades. Protein kinases have emerged as primary objectives for therapeutic interventions, particularly in the context of cancer treatment. At present, 69 therapeutics have been approved by the FDA that target approximately 24 protein kinases, which are specifically prescribed for the treatment of neoplastic illnesses. These novel agents specifically inhibit certain protein kinases, such as receptor protein-tyrosine kinases, protein-serine/threonine kinases, dual-specificity kinases, nonreceptor protein-tyrosine kinases, and receptor protein-tyrosine kinases. This review presents a comprehensive overview of novel targets of kinase inhibitors, with a specific focus on cyclin-dependent kinases (CDKs) and epidermal growth factor receptor (EGFR). The majority of the reviewed studies commenced with an assessment of cancer cell lines and concluded with a comprehensive biological evaluation of individual kinase targets. The reviewed articles provide detailed information on the structural features of potent anticancer agents and their specific activity, which refers to their ability to selectively inhibit cancer-promoting kinases including CDKs and EGFR. Additionally, the latest FDA-approved anticancer agents targeting these enzymes were highlighted accordingly.

Synthesis and evaluation of chemical linchpins for highly selective CK2α targeting

Casein kinase-2 (CK2) are serine/threonine kinases with dual co-factor (ATP and GTP) specificity, that are involved in the regulation of a wide variety of cellular functions. Small molecules targeting CK2 have been described in the literature targeting different binding pockets of the kinase with a focus on type I inhibitors such as the recently published chemical probe SGC-CK2-1. In this study, we investigated whether known allosteric inhibitors binding to a pocket adjacent to helix αD could be combined with ATP mimetic moieties defining a novel class of ATP competitive compounds with a unique binding mode. Linking both binding sites requires a chemical linking moiety that would introduce a 90-degree angle between the ATP mimetic ring system and the αD targeting moiety, which was realized using a sulfonamide. The synthesized inhibitors were highly selective for CK2 with binding constants in the nM range and low micromolar activity. While these inhibitors need to be further improved, the present work provides a structure-based design strategy for highly selective CK2 inhibitors.

Design, synthesis, and evaluation of formylpiperazine analogs of Ferrostatin-1 as novel improved ferroptosis inhibitors

In this study, a series of new formylpiperazine-derived ferroptosis inhibitors were designed and synthesized based on the structure of a known ferroptosis inhibitor, ferrostatin-1 (Fer-1). The anti-ferroptosis activity of these synthetic compounds in human umbilical vein endothelial cells (HUVECs) induced by Erastin was evaluated. It was found that some of the new compounds, especially compound 26, showed potent anti-ferroptosis activity, as evidenced by its ability to restore cell viability, reduce iron accumulation, scavenge reactive oxygen species, maintain mitochondrial membrane potential, increase GSH levels, decrease LPO and MDA content, and upregulate GPX4 expression. Moreover, compound 26 exhibited superior microsomal stability than Fer-1. The present results suggest that compound 26 is a promising lead compound for the development of new ferroptosis inhibitors for the treatment of vascular diseases.

Antineoplastic indole-containing compounds with potential VEGFR inhibitory properties

Cancer is one of the most significant health challenges worldwide. Various techniques, tools and therapeutics/materials have been developed in the last few decades for the treatment of cancer, together with great interest, funding and efforts from the scientific society. However, all the reported studies and efforts seem insufficient to combat the various types of cancer, especially the advanced ones. The overexpression of tyrosine kinases is associated with cancer proliferation and/or metastasis. VEGF, an important category of tyrosine kinases, and its receptors (VEGFR) are hyper-activated in different cancers. Accordingly, they are known as important factors in the angiogenesis of different tumors and are considered in the development of effective therapeutic approaches for controlling many types of cancer. In this case, targeted therapeutic approaches are preferable to the traditional non-selective approaches to minimize the side effects and drawbacks associated with treatment. Several indole-containing compounds have been identified as effective agents against VEGFR. Herein, we present a summary of the recent indolyl analogs reported within the last decade (2012-2023) with potential antineoplastic and VEGFR inhibitory properties. The most important drugs, natural products, synthesized potent compounds and promising hits/leads are highlighted. Indoles functionalized and conjugated with various heterocycles beside spiroindoles are also considered.

Tailored horseshoe-shaped nicotinonitrile scaffold as dual promising c-Met and Pim-1 inhibitors: Design, synthesis, SAR and in silico study

For the horseshoe tactic to succeed in inhibiting c-Met and Pim-1, the nicotinonitrile derivatives (2a-n) were produced in high quantities by coupling acetyl phenylpyrazole (1) with the proper aldehydes and ethyl cyanoacetate under basic conditions. Consistent basic and spectroscopic data (NMR, IR, Mass, and HPLC) supported the new products' structural findings. With IC50 potency in nanomolar ranges, these compounds had effectively repressed them, particularly compounds 2d and 2 h, with IC50 values below 200 nM. The most potent compounds (2d and 2 h) were tested for their antitumor effects against prostate (PC-3), colon (HCT-116), and breast (MDA-MB-231) and were evaluated in comparison to the anticancer drug tivantinib using the MTT assay. Similar to tivantinib, these compounds showed good antiproliferative properties against the HCT-116 tumor cells while having low cytotoxicity towards healthy fetal colon (FHC) cells. In the HCT-116 cell line, their ability to trigger the apoptotic cascade was also investigated by looking at the level of Bax and Bcl-2 as well as the activation of the proteolytic caspase cascade. When HCT-116 cells were exposed to compounds 2d and 2 h in comparison to the control, active caspase-3 levels increased. The HCT-116 cell line also upregulated Bcl-2 protein levels and downregulated Bax levels. Additionally, when treated with compound 2d, the HCT-116 cell cycle was primarily stopped at the S phase. Compared to the control, compound 2d treatment significantly inhibited the protein expression levels of c-Met and Pim-1 kinases in the treated HCT-116 cells. Thorough molecular modeling analyses, such as molecular docking and dynamic simulation, were performed to ascertain the binding mechanism and stability of the target compounds.

Alkaloids as Additional Weapons in the Fight against Breast Cancer: A Review

Breast carcinoma is among the most frequent cancerous tumour in females around the globe. The major modalities now employed in the therapeutic management of breast cancer include surgeries, chemotherapy, and specialized medicines. Despite their potential to help individuals' problems, they are also associated with many negative impacts. As a result, natural products are increasingly regarded to be a preferable alternative. Alkaloids are essential biochemical substances that can be used to develop new drugs. Numerous alkaloids that originate from natural plants have been shown in vitro and in vivo to have anti-proliferation and anti-metastasis actions on different kinds of carcinoma. According to the data collected in this study, the utilization of alkaloids as anti-tumor medicines appears to be extremely potent; nevertheless, extensive studies and clinical trials are required before utilizing individual alkaloids. In this overview, we provide a detailed and vital exploration of pre-existing alkaloids possessing anti-tumor activities due to bioactive compounds. This study also includes an overview of synthesized analogues and pharmacological characteristics that will be beneficial to scientists working on alkaloids for medicinal purposes. In a recent survey of the literature, alkaloids are an important component of plantderived antitumor medicines that hold great potential for the future development of cancer therapy and preventive therapies. We have also discussed structural analysis relationship (SAR) studies. Moreover, it covers clinical trial medications and FDA-approved medicines from the last five years that will be useful in further research.

Design, Synthesis, and Acute Toxicity Assays for Novel Thymoquinone Derivative TQFL12 in Mice and the Mechanism of Resistance to Toxicity

TQFL12 is a novel derivative designed and synthesized on the basis of Thymoquinone (TQ) which is extracted from Nigella sativa seeds. We have demonstrated that TQFL12 was more effective in the treatment of TNBC than TQ. In order to directly reflect the acute toxicity of TQFL12 in vivo, in this study, we designed, synthesized, and compared it with TQ. The mice were administered drugs with different concentration gradients intraperitoneally, and death was observed within one week. The 24 h median lethal dose (LD₅₀) of TQ was calculated to be 33.758 mg/kg, while that of TQFL12 on the 7th day was 81.405 mg/kg, and the toxicity was significantly lower than that of TQ. The liver and kidney tissues of the dead mice were observed by H&E staining. The kidneys of the TQ group had more severe renal damage, while the degree of the changes in the TQFL12 group was obviously less than that in the TQ group. Western blotting results showed that the expressions of phosphorylated levels of adenylate-activated protein kinase AMPKα were significantly up-regulated in the kidneys of the TQFL12 group. Therefore, it can be concluded that the acute toxicity of TQFL12 in vivo is significantly lower than that of TQ, and its anti-toxicity mechanism may be carried out through the AMPK signaling pathway, which has a good prospect for drug development.