Design and synthesis of novel thiobarbituric acid derivatives targeting both wild-type and BRAF-mutated melanoma cells

Synthesis, molecular docking and DFT analysis of novel bis-Schiff base derivatives with thiobarbituric acid for α-glucosidase inhibition assessment

A library of novel bis-Schiff base derivatives based on thiobarbituric acid has been effectively synthesized by multi-step reactions as part of our ongoing pursuit of novel anti-diabetic agents. All these derivatives were subjected to in vitro α-glucosidase inhibitory potential testing after structural confirmation by modern spectroscopic techniques. Among them, compound 8 (IC50 = 0.10 ± 0.05 µM), and 9 (IC50 = 0.13 ± 0.03 µM) exhibited promising inhibitory activity better than the standard drug acarbose (IC50 = 0.27 ± 0.04 µM). Similarly, derivatives (5, 6, 7, 10 and 4) showed significant to good inhibitory activity in the range of IC50 values from 0.32 ± 0.03 to 0.52 ± 0.02 µM. These derivatives were docked with the target protein to elucidate their binding affinities and key interactions, providing additional insights into their inhibitory mechanisms. The chemical nature of these compounds were reveal by performing the density functional theory (DFT) calculation using hybrid B3LYP functional with 6-311++G(d,p) basis set. The presence of intramolecular H-bonding was explored by DFT-d3 and reduced density gradient (RGD) analysis. Furthermore, various reactivity parameters were explored by performing TD-DFT at CAM-B3LYP/6-311++G(d,p) method.

Treatment with a new barbituric acid derivative suppresses diet-induced metabolic dysfunction and non-alcoholic fatty liver disease in mice

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, often accompanied by obesity, diabetes, and increased risks of depression and anxiety. Currently, there are no FDA-approved drugs to treat NAFLD and its related systemic symptoms. Previously, we identified a new barbituric acid derivative (BA-5) that expressed effectiveness against fibrosis and drug-resistant hepatocellular carcinoma.

AIMS

This study investigated the potential of BA-5 against high-fat diet (HFD)-induced NAFLD and mood disorders in mice.

MAIN METHODS

Six-weeks-old male C57BL/6 mice were fed with a 45 % HFD for 8 weeks to induce NAFLD and associated metabolic disorders. Mice were treated with a BA-5 and the therapeutic effects and the underlying molecular mechanisms were investigated.

KEY FINDINGS

Administration of BA-5 significantly reduced serum levels of alanine aminotransferase (ALT), low-density lipoprotein (LDL), fatty acids (FA), and triglycerides (TG) in HFD-fed mice. BA-5 treatment decreased expressions of hepatic lipogenesis-related markers (acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and ATP-citrate lyase (ACLY)), increased fatty acid oxidation markers (carnitine palmitoyltransferase 1A (CPT1A) and acyl-CoA oxidase 1 (ACOX1)), and attenuated hepatic fat accumulation in HFD-fed mice. Moreover, HFD-induced adipocyte size enlargement and activation of lipolysis markers such as phosphorylated (p)-hormone-sensitive lipase (HSL) 565, p-HSL 660, and perilipin were inhibited in BA-5-treated mice. Notably, HFD-induced anxiety- and depression-like behaviors significantly improved in the BA-5 treated group through enhanced anti-inflammatory responses in the hippocampus.

SIGNIFICANCE

This study provides new insights into clinical therapeutic strategies of barbituric acid derivatives for HFD-induced NAFLD and associated mood disturbances.

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.

Recent development of multi-target VEGFR-2 inhibitors for the cancer therapy

Vascular epidermal growth factor receptor-2 (VEGFR-2), as an important tyrosine transmembrane protein, plays an important role in regulating endothelial cell proliferation and migration, regulating angiogenesis and other biological functions. VEGFR-2 is aberrantly expressed in many malignant tumors, and it is also related to the occurrence, development, and growth of tumors and drug resistance. Currently, there are nine VEGFR-2 targeted inhibitors approved by US.FDA for clinical use as anticancer drugs. Due to the limited clinical efficacy and potential toxicity of VEGFR inhibitors, it is necessary to develop new strategies to improve the clinical efficacy of VEGFR inhibitors. The development of multitarget therapy, especially dual-target therapy, has become a hot research field of cancer therapy, which may provide an effective strategy with higher therapeutic efficacy, pharmacokinetic advantages and low toxicity. Many groups have reported that the therapeutic effects could be improved by simultaneously inhibiting VEGFR-2 and other targets, such as EGFR, c-Met, BRAF, HDAC, etc. Therefore, VEGFR-2 inhibitors with multi-targeting capabilities have been considered to be promising and effective anticancer agents for cancer therapy. In this work, we reviewed the structure and biological functions of VEGFR-2, and summarized the drug discovery strategies, and inhibitory activities of VEGFR-2 inhibitors with multi-targeting capabilities reported in recent years. This work might provide the reference for the development of VEGFR-2 inhibitors with multi-targeting capabilities as novel anticancer agents.

Incorporating Selenium into Heterocycles and Natural Products─From Chemical Properties to Pharmacological Activities

Selenium (Se)-containing compounds have emerged as potential therapeutic agents for the treatment of a range of diseases. Through tremendous effort, considerable knowledge has been acquired to understand the complex chemical properties and biological activities of selenium, especially after its incorporation into bioactive molecules. From this perspective, we compiled extensive literature evidence to summarize and critically discuss the relationship between the pharmacological activities and chemical properties of selenium compounds and the strategic incorporation of selenium into organic molecules, especially bioactive heterocycles and natural products. We also provide perspectives regarding the challenges in selenium-based medicinal chemistry and future research directions.

Contribution of Knoevenagel Condensation Products towards Development of Anticancer Agents: An Updated Review

Knoevenagel condensation is an entrenched, prevailing, prominent arsenal following greener principles in the generation of α, β-unsaturated ketones/carboxylic acids by involving carbonyl functionalities and active methylenes. This reaction has proved to be a major driving force in many multicomponent reactions indicating the prolific utility towards the development of biologically fascinating molecules. This eminent reaction was acclimatised on different pharmacophoric aldehydes (benzimidazole, β-carboline, phenanthrene, indole, imidazothiadiazole, pyrazole etc.) and active methylenes (oxindole, barbituric acid, Meldrum's acid, thiazolidinedione etc.) to generate the library of chemical compounds. Their potential was also explicit to understand the significance of functionalities involved, which thereby evoke further developments in drug discovery. Furthermore, most of these reaction products exhibited remarkable anticancer activity in nanomolar to micromolar ranges by targeting different cancer targets like DNA, microtubules, Topo-I/II, and kinases (PIM, PARP, NMP, p300/CBP) etc. This review underscores the efficiency of the Knoevenagel condensation explored in the past six-year to generate molecules of pharmacological interest, predominantly towards cancer. The present review also provides the aspects of structure-activity relationships, mode of action and docking study with possible interaction with the target protein.

Catalytic Asymmetric Synthesis of Chiral Thiohydantoins via Domino Cyclization Reaction of β,γ-Unsaturated α-Ketoester and N,N'-Dialkylthiourea

The first catalytic asymmetric route to synthesize chiral thiohydantoins containing a quaternary stereogenic center has been established utilizing a chiral phosphoric acid-catalyzed domino cyclization reaction of N,N'-dialkyl thioureas with β,γ-unsaturated...

Design, synthesis, and anticancer activity of cinnamoylated barbituric acid derivatives

Background As reactive and biomimetic pharmacophores, heterocycles have found a potent impact in the domain of medicinal chemistry. Aim This work deals with the design and synthesis of 18 barbituric acid derivatives bearing 1,3-dimethylbarbituric acid and cinnamic acid scaffolds to find potent anticancer agents. Methodology The target molecules were obtained through Knoevenagel condensation and acylation reaction. The cytotoxicity was assessed by the MTT assay. Flowcytometry was performed to determined the cell cycle arrest, apoptosis, ROS levels and the loss of MMP. The ratios of GSH/GSSG and the MDA levels were determined by using UV spectrophotometry. Results The results revealed that introducing substitutions (-CF3, -OCF3, -F) on the meta- of the benzyl ring of barbituric acid derivatives led to a considerable increase in the antiproliferative activities compared with that of corresponding ortho- and para-substituted barbituric acid derivatives. Mechanism investigation implied that the 1c could increase the ROS and MDA level, decrease the ratio of GSH/GSSG and MMP, and lead to cell cycle arrest. Conclusion Further research is needed for structural optimization to enhance hydrophilicity, thereby improve the biological activity of these compounds.

Barbiturates: A Review of Synthesis and Antimicrobial Research Progress

BACKGROUND

Barbituric acid and its derivatives have turned heads for several years as an indispensable class of compounds in the pharmaceutical industry because of their vast assortment of biological activities such as anticonvulsants, hypnotics, anti-diabetic, antiviral, anti-AIDS, anti-cancer, anti-microbial and anti-oxidant etc. Plethoras of studies have shed light on the properties, synthesis, and reactivity of these compounds. The depiction of multiple biological activities by barbiturates compelled us and by virtue of which herein we have mediated over the progress of synthesis of numerous kinds of compounds derived from barbituric acid with well-known and typical examples from 2016 to the present.

OBJECTIVE

The review focuses on the advancements in methods of synthesis of barbituric acid derivatives and their applications as antimicrobial agents.

CONCLUSION

This review will help future researchers to analyze the previous studies and to explore new compounds for the development of efficient antimicrobial drugs.

Treatment with a New Barbituric Acid Derivative Exerts Antiproliferative and Antimigratory Effects against Sorafenib Resistance in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a common cause of cancer death worldwide. Sorafenib, a multikinase inhibitor, is the first-line drug approved by the Food and Drug Administration (FDA) for the treatment of patients with advanced HCC. However, most patients who continuously receive sorafenib may acquire resistance to this drug. Therefore, it is important to develop a new compound to treat liver cancer and sorafenib-resistant liver cancer. Barbituric acid derivatives have been used as antiasthmatic drugs in the clinic. We previously reported that a novel barbituric acid derivative inhibited carbon tetrachloride-induced liver fibrosis in mice, but its effects on liver cancer remain unknown. Thus, the purpose of this study was to investigate the antitumor effect of barbituric acid derivatives on HCC cells and sorafenib-resistant HCC cells (HCC-SRs). Our findings reveal that one of the barbituric acid derivatives, BA-5, significantly inhibited HCC and HCC-SR cell viability in a dose- and time-dependent manner. Therefore, compound BA-5 was selected for further experiments. Western blot data revealed that BA-5 treatment decreased the phosphorylation of AKT/p70s6k without affecting the MAPK pathway and increased cleaved PARP and cleaved caspase-7 in both HCC and HCC-SR cells. Since epithelial-mesenchymal transition plays a significant role in regulating cancer invasion and migration, we used the wound healing assay to evaluate the antimigratory effect of compound BA-5. The results showed that BA-5 treatment inhibited HCC and HCC-SR cell migration and reduced Vimentin protein expression. These results were confirmed by microarray analysis showing that BA-5 treatment influenced cancer cell motility and growth-related pathways. In the xenograft mouse model experiment, BA-5 administration significantly inhibited HCC cancer cell growth in mice. Furthermore, the combination of BA-5 with a low dose of regorafenib synergistically inhibited HCC-SR cell proliferation. In conclusion, our study showed that the barbituric acid derivative BA-5 is a new candidate for HCC and sorafenib-resistant HCC therapy.

Novel potent substituted 4-amino-2-thiopyrimidines as dual VEGFR-2 and BRAF kinase inhibitors

In the present study, we report the discovery of a novel class of substituted 4-amino-2-thiopyrimidines as antiangiogenic and antiproliferative agents. Structural hybridization between 4-substituted aminopyrimidines (VEGFR-2 inhibitors) and 2-thioxopyrimidines (BRAF inhibitors) was carried out to afford substituted 4-amino-2-thiopyrimidines as type II dual VEGFR-2/BRAF inhibitors. Our design strategy was tailored such that the 4-amino-2-thiopyrimidine scaffold is to be accommodated in the central gate area of the inactive DFG-out conformation of both enzymes. On one side, the hydrophobic substituent on the 4-amino group would occupy the hydrophobic back pocket and on the other side the substituent on the sulfide moiety should extend to fit in the hinge region (front pocket). Molecular docking simulations confirmed the ability of the designed compounds to accomplish the key interactions in VEGFR-2 and BRAF active sites. Most of the synthesized substituted 4-amino-2-thiopyrimidines demonstrated potent VEGFR-2 inhibitory activity at submicromolar concentrations. Compounds 8a, 8d, 9c and 9e showed IC₅₀ = 0.17, 0.12, 0.17 and 0.19 μM, respectively against VEGFR-2 in comparison to sorafenib (I) IC₅₀ = 0.10 μM and regorafenib (II) IC₅₀ = 0.005 μM. While compounds 9c, 9d and 10a showed IC₅₀ = 0.15, 0.22 and 0.11 μM, respectively against BRAF-WT. At 10 μM concentration 9c revealed promising in vitro broad-spectrum antiproliferative activity against cancer cell lines with growth inhibition percent ranging from 10 to 90%. Moreover, compounds 7b, 8d, 9a, 9b, 9c and 9d showed potent activity against MCF7 cell line (IC₅₀ = 17.18, 17.20, 19.98, 19.61, 13.02 and 16.54 μM, respectively). On the other hand, compounds 9c, 9d and 10d were found to be the most potent compounds against T-47D cell line (IC₅₀ = 2.18, 8.09 and 4.36 μM, respectively). Studying the effect of the most potent compounds on VEGFR-2 level in MCF7 cell line revealed that 9c and 9d showed inhibition percent of 84 and 80%, respectively, in comparison to sorafenib (I) (% inhibition = 90%).

Sustainable and scalable synthesis of polysubstituted bis-1,2,4-triazoles, bis-2-iminothiazolines and bis-thiobarbiturates using bis-N,N-disubstituted thioureas as versatile substrate

An expedient and tandem regioselective one-pot protocol for the sono-synthesis of bis-[1,2,4]-triazol-3-yl amines and bis-2-iminothiazolines from corresponding bis-1,3-disubstituted thioureas has been developed. The products' regioselectivity correlate well with the pK as of the parent amines, in which the amine possessing higher pK a goes to the ring nitrogen, whereas the other nitrogen remains flanked as an exocyclic nitrogen of the bis-triazole or bis-thiazole moieties. Further, the sonochemical preparation of both bis-5-(2-nitrobenzylidene) thiobarbiturates and bis-2-thioxoimidazolidine-4,5-diones from bis-1,3-disubstituted thioureas has also been achieved. The obtained bis-5-(2-nitrobenzylidene)thiobarbiturates easily underwent reductive cyclization to afford the corresponding bis-5-benzo[c]isoxazol-3-ylidenethiobarbiturates. The scope and limitations of these strategies have been studied. Moreover, the suggested methodologies have advantages such as broad functional group tolerance, mild conditions, operational simplicity and applicability on a gram scale. Furthermore, the protocols scored well in a number of green metrics, subsequently showing these approaches to be environmentally benign and sustainable processes.