Design, synthesis, anticancer, and antibacterial evaluation of some quinazolinone-based derivatives as DHFR inhibitors

New S-substituted-3-phenyltetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4(3H)-one scaffold with promising anticancer activity profile through the regulation and inhibition of mutated B-RAF signaling pathway

Novel 3-phenyltetrahydrobenzo[4,5]thieno[2,3-d]pyrimidine derivatives were synthesized and screened for their antiproliferative activity against a panel of 60 cancer cell lines. Derivatives 5b, 5f, and 9c showed significant antitumor activity at a single dose with mean growth inhibition of 55.62%, 55.79%, and 71.40%, respectively. These compounds were further investigated against HCT-116, colon cancer cell line, and FHC, normal colon cell line. Compound 9c showed the highest activity with IC50 = 0.904 ± 0.03 µM and SI = 20.42 excelling doxorubicin which scored IC50 = 2.556 ± 0.09 µM and SI = 6.19. Compound 9c was also the most potent against B-RAFWT and mutated B-RAFV600E with IC50 = 0.145 ± 0.005 and 0.042 ± 0.002 µM, respectively in comparison with vemurafenib with IC50 = 0.229 ± 0.008 and 0.038 ± 0.001 µM, respectively. The cell cycle analysis showed that 9c increased the cell population and induced an arrest in the cell cycle of HCT-116 cancer cells at the G0-G1 stage with 1.23-fold. Apoptosis evaluation showed that compound 9c displayed an 18.18-fold elevation in total apoptosis of HCT-116 cancer cells in comparison to the control. Compound 9c increased the content of caspase-3 by 3.52-fold versus the control. A molecular modeling study determined the binding profile and interaction of 9c with the B-RAF active site.

Synthesis, in vitro biological evaluation and in silico studies of novel pyrrolidine derived thiosemicarbazones as dihydrofolate reductase inhibitors

Dihydrofolate reductase (DHFR) is a crucial enzyme involved in folate metabolism and serves as a prime target for anticancer and antimicrobial therapies. In this study, a series of 4-pyrrolidine-based thiosemicarbazones were synthesized and evaluated for their DHFR inhibitory activity. The synthesis involved a multistep procedure starting from readily available starting materials, leading to the formation of diverse thiosemicarbazone 5(a-r) derivatives. These compounds were then subjected to in vitro assays to evaluate their inhibitory potential against DHFR enzyme. The synthesized compounds 5(a-r) exhibited potent inhibition with IC50 values in the range of 12.37 ± 0.48 μM to 54.10 ± 0.72 μM. Among all the derivatives 5d displayed highest inhibitory activity. Furthermore, molecular docking and ADME studies were performed to understand the binding interactions between the synthesized compounds and the active site of DHFR. The in vitro and in silico data were correlated to identify compounds with promising inhibitory activity and favorable binding modes. This comprehensive study provides insights into the structure-activity relationships of 4-pyrrolidine-based thiosemicarbazones as DHFR inhibitors, offering potential candidates for further optimization towards the development of novel therapeutic agents.

Design, synthesis, biological evaluation, and docking studies of novel triazolo[4,3-b]pyridazine derivatives as dual c-Met/Pim-1 potential inhibitors with antitumor activity

Interest has been piqued in c-Met and Pim-1, potential new cancer treatment targets. A variety of triazolo[4,3-b]pyridazine derivatives were synthesized to create powerful dual c-Met/Pim-1 inhibitors having the pharmacophoric elements of both enzyme inhibitors. All derivatives were screened for their cytotoxic effects on 60 cancer cell lines. Compounds 4g and 4a, had strong antiproliferative cytotoxic impacts on tumor cells, with mean GI% values of 55.84 and 29.08%, respectively. Research revealed that 4g has more powerful inhibitory activity against c-Met and Pim-1, with IC50 of 0.163 ± 0.01 and 0.283 ± 0.01 μM, respectively than the reference and derivative 4a. Moreover, compound 4g was the subject of an additional investigation into biological processes. The findings showed that compound 4g caused MCF-7 cells to arrest in the S stage of the cell cycle. Also, it accelerated the progress of apoptosis 29.61-fold more than the control. Compound 4g demonstrated a significantly higher level of caspase-9 and a decreased level of p-PI3K, p-AKT, and p-mTOR compared to staurosporine. Later, analysis of 4g showed good drug-ability and pharmacokinetic properties. A similar mode of interaction at the ATP-binding site of c-Met and Pim-1 compared to the docked ligands was suggested by additional docking studies of compound 4g.

Design, synthesis, and biological evaluation of novel thiazole derivatives as PI3K/mTOR dual inhibitors

The development of anticancer drugs targeting both PI3K and mTOR pathways is recognized as a promising cancer therapeutic approach. In the current study, we designed and synthesized seventeen new thiazole compounds to investigate their effect on both PI3K and mTOR as well as their anti-apoptotic activity. All the synthesized thiazoles were investigated for their antiproliferative activity on a panel of 60 different cancer cell lines at the National Cancer Institute. Compounds 3b and 3e were selected for further investigation at five dose concentrations due to their effective growth inhibiting activity. Compounds 3b and 3e were further evaluated for their in vitro inhibitory activities against PI3Kα and mTOR compared to alpelisib and dactolisib, respectively as reference drugs. The inhibitory effect of compound 3b on PI3Kα was similar to alpelisib, but it showed weaker inhibitory activity on mTOR compared to dactolisib. Moreover, compound 3b exhibited significantly higher inhibitory activity compared to compound 3e against both PI3Kα and mTOR. The cell cycle analysis showed that compounds 3b and 3e induced G0-G1 phase cell cycle arrest in the leukemia HL-60(TB) cell line. Meanwhile, they significantly increased the total apoptotic activity which was supported by an increase in the level of caspase-3 in leukemia HL-60(TB) cell lines. Molecular docking experiments provided additional explanation for these results by demonstrating the ability of these derivatives to form a network of key interactions, known to be essential for PI3Kα/mTOR inhibitors. All these experimental results suggested that 3b and 3e are potential PI3Kα/mTOR dual inhibitors and could be considered promising lead compounds for the development of anticancer agents.

Thiazolation of phenylthiosemicarbazone to access new thiazoles: anticancer activity and molecular docking

Aim: Novel thiazole hybrids were synthesized via thiazolation of 4-phenylthiosemicarbazone (4). Materials & methods: The anticancer activity against the NCI 60 cancer cell line panel. Results: Methyl 2-(2-((1-(naphthalen-2-yl)ethylidene)hydrazineylidene)-4-oxo-3-phenylthiazolidin-5-ylidene)acetate (6a) showed significant anticancer activity at 10 μM with a mean growth inhibition (GI) of 51.18%. It showed the highest cytotoxic activity against the ovarian cancer OVCAR-4 with an IC50 of 1.569 ± 0.06 μM. Compound 6a inhibited PI3Kα with IC50 = 0.225 ± 0.01 μM. Moreover, compound 6a revealed a decrease of Akt and mTOR phosphorylation in OVCAR-4 cells. In addition, antibacterial activity showed that compounds 11 and 12 were the most active against Staphylococcus aureus. Conclusion: Compound 6a is a promising molecule that could be a lead candidate for further studies.

Design, Synthesis, and Biological Evaluation of 5-(5-Iodo-2-isopropyl-4-methoxyphenoxy)pyrimidine-2,4-diamine (AF-353) Derivatives as Novel DHFR Inhibitors against Staphylococcus aureus

The high lethality of Staphylococcus aureus infections and the emergence of antibiotic resistance make the development of new antibiotics urgent. Our previous work identified a hit compound h1 (AF-353) as a novel Mycobacterium tuberculosis (Mtb) dihydrofolate reductase (DHFR) inhibitor. Herein, we analyzed the antimicrobial profile of h1 and performed a comprehensive structure-activity relationship (SAR) assay based on h1. The representative compound j9 exhibited potent antibacterial activity against S. aureus without cross-resistance to other antimicrobial classes. Multiple genetic and biochemical approaches showed that j9 directly binds to SaDHFR, resulting in strong inhibition of its enzymatic activity (IC50 = 0.97 nM). Additionally, j9 had an acceptable in vivo safety profile and oral bioavailability (F = 40.7%) and also showed favorable efficacy in a mouse model of methicillin-resistant S. aureus (MRSA) skin infection. Collectively, these findings identified j9 as a novel SaDHFR inhibitor with the potential to combat drug-resistant S. aureus infections.

Novel pyrazolo[3,4-d]pyrimidine derivatives: design, synthesis, anticancer evaluation, VEGFR-2 inhibition, and antiangiogenic activity

A novel series of 12 pyrazolo[3,4-d]pyrimidine derivatives were created and evaluated in vitro for their antiproliferative activity against the NCI 60 human tumor cell line panel. Compounds 12a-d displayed significant antitumor activity against MDA-MB-468 and T-47D (breast cancer cell lines), especially compound 12b, which exhibited the highest anticancer activity against MDA-MB-468 and T-47D cell lines with IC50 values of 3.343 ± 0.13 and 4.792 ± 0.21 μM, respectively compared to staurosporine with IC50 values of 6.358 ± 0.24 and 4.849 ± 0.22 μM. The most potent cytotoxic derivatives 12a-d were studied for their VEGFR-2 inhibitory activity to explore the mechanism of action of these substances. Compound 12b had potent activity against VEGFR-2 with an IC50 value of 0.063 ± 0.003 μM, compared to sunitinib with IC50 = 0.035 ± 0.012 μM. Moreover, there was an excellent reduction in HUVEC migratory potential that resulted in a significant disruption of wound healing patterns by 23% after 72 h of treatment with compound 12b. Cell cycle and apoptosis investigations showed that compound 12b could stop the cell cycle at the S phase and significantly increase total apoptosis in the MDA-MB-468 cell line by 18.98-fold compared to the control. Moreover, compound 12b increased the caspase-3 level in the MDA-MB-468 cell line by 7.32-fold as compared to the control.

Design, Synthesis, Antitumour Evaluation, and In Silico Studies of Pyrazolo-[1,5-c]quinazolinone Derivatives Targeting Potential Cyclin-Dependent Kinases

An efficient, straightforward, and metal-free methodology to rapidly access functionalised pyrazolo-[1,5-c]quinazolinones via a [3 + 2] dipolar cycloaddition and regioselective ring expansion process was developed. The synthesised compounds were characterised by methods such as NMR, HRMS, and HPLC. The in vitro antiproliferative activity against A549 cells (non-small cell lung cancer) was significant for compounds 4i, 4m, and 4n with IC50 values of 17.0, 14.2, and 18.1 μM, respectively. In particular, compounds 4t and 4n showed inhibitory activity against CDK9/2. Predicted biological target and molecular modelling studies suggest that the compound 4t may target CDKs for antitumour effects. The synthesised derivatives were considered to have moderate drug-likeness and sufficient safety in silico. In summary, a series of pyrazolo-[1,5-c]quinazolinone derivatives with antitumour activity is reported for the first time. We provide not only a simple and efficient synthetic method but also helpful lead compounds for the further development of novel cyclin-dependent kinase (CDK) inhibitors.

Design, synthesis, anticancer evaluation, and in silico studies of some thieno[2,3-d]pyrimidine derivatives as EGFR inhibitors

New series of 20 thieno[2,3-d]pyrimidine derivatives have been synthesized. The National Cancer Institute evaluated all the newly synthesized compounds for their antiproliferative activity against a panel of 60 cancer cell lines. Compound 7b exhibited a remarkable antineoplastic activity at 10 µM dose and was therefore tested at five dose concentrations. The significant and broad-spectrum antineoplastic action of compound 7b was observed against 37 of the tested cancer cell lines with a dose that inhibits 50% of the growth compared to control values in the micromolar range of 1.95-9.6 µM. The dose which inhibits the growth completely in the cytostatic range of 3.99-100 µM was also observed. Compound 7b effectively inhibited epidermal growth factor receptor (EGFR) with 50% inhibition concentration value (IC50 ) = 0.096 ± 0.004 compared to erlotinib with IC50  = 0.037 ± 0.002. Moreover, compound 7b revealed a powerful downregulation effect on total EGFR concentration and its phosphorylation. In addition, compound 7b inhibited phosphatidylinositol 3-kinase, protein kinase B, and the mammalian target of rapamycin pathway phosphorylation. Furthermore, compound 7b raised total apoptosis by 21.93-fold in the ovarian cancer cell line (OVCAR-4) and caused an arrest in the cell cycle in the G1/S phase. It also raised the level of caspase-3 by 4.72-fold. Furthermore, to determine the binding manner of the most effective derivatives and validate their capacity to comply with the pharmacophoric properties necessary for EGFR inhibition, they were docked into the active site of the EGFR.