Design, synthesis and in vivo antitumor activity of novel 3, 4 di-substituted quinazoline derivatives

The present study attempted to design and synthesise isomeric new series of quinazoline-4-one/4-thione derivatives, based on the pharmacophoric model of CNS activity by structural modifications retaining the essential structural features for the activity and evaluated for their anticonvulsant and CNS depressant properties. Epilepsy, a disorder of unprovoked seizures is a multifaceted disease affecting individuals of all ages with a particular predilection for the very young and old. In addition to seizures, many patients often report cognitive and psychiatric problems associated with both the seizures themselves and its therapy.  A series of 7-chloro-3-[substituted (amino/phenylamino)]-2-phenyl quinazolin-4 (3H)-one/thione derivatives and 1-(7-chloro-4-oxo/-2-phenylquinazoline-3 (4H-yl)) substituted urea derivatives were synthesized. The reaction scheme proceeds through the intermediate 7-chloro-2-phenyl-4H-benzo[d] [1, 3] oxazin-4-one. The newly synthesized compounds were characterized by infrared (IR), 1H nuclear magnetic resonance (NMR) and mass spectra (m/z) and elemental analysis. The maximum electroshock (MES) seizure test and Porsolt's behavioural despair test (forced swimming) were used to examine the anti-convulsant and CNS depressant activity, respectively. To evaluate any potential alterations in motor coordination brought on by the test compounds, the rota-rod test was conducted. The synthesis of quinazoline derivatives with a common skeleton was unequivocally confirmed by the physicochemical and spectroscopic data. The synthesised compounds were evaluated for their anticonvulsant and CNS depressant properties. Six compounds (IIc, IIg, IIj, IIIc, IIIg, IIIj) exhibited a good activity profile in CNS depressant activity. Five compounds (IIc, IIg, IIj, IIIg, IIIh) showed protection against MES-induced seizures. Compounds IIc, IIg, IIj, IIIc, IIIg, IIIj, and IIIh were found to be a potent compound which may be effective as a potential source for the development of CNS depressant and anti-convulsant drugs with lesser side effects.

Quinazoline derivatives, an important structure in drug discovery, have attracted increasing attention from the pharmaceutical researchers because of their various pesticidal activities such as antibacterial, antifungal, insecticidal, herbicidal, antiviral and acaricidal activities. Introducing different pharmacophores into quinazoline framework can afford a series of quinazoline derivatives which possesses better pesticidal activities. This paper reviewed the study on the synthesis and pesticidal activities of the quinazoline derivatives from year 2000 to 2016.

Background and Aims: Alzheimer's disease is a neurodegenerative disorder in which the death of brain cells causes memory loss and cognitive decline. It is one of the leading causes of mortality worldwide. Several different hallmarks of the disease have been reported such as low levels of acetylcholine, deposits of β-amyloid around neurons, hyperphosphorylated tau protein, oxidative stress, etc. Pharmacotherapy for this disease currently depends on using acetylcholinesterase inhibitors and N-methyl-D-aspartate receptor antagonists. They provide only symptomatic relief and mostly targets cognitive revival. Quinazoline derivatives were recently reported as being a valuable template in the treatment of many neurodegenerative disorders. Quinazoline based compounds were declared as being potential anti AD agents. This research focuses on the synthesis of novel quinazoline derivatives 3 and 4. Methods: Novel quinazoline derivatives 3 and 4 were synthesized starting from 2-(methylamino)benzamide by consecutive steps. The structures of these compounds have been characterized using different analytical and spectral methods: TLC, GC-MS, 1 H-NMR and 13C-NMR. Results: This study revealed the synthesis of the novel compounds 3 and 4 with excellent yields equalling 97% and 73.1% respectively. Conclusion: Novel quinazoline derivatives compounds 3 and 4 were obtained. These compounds might be promising lead compounds for potential poly-functional anti-Alzheimer's agents in future work.

Series of 7-chloro-3-[substituted (amino/phenyl amino)]-2-phenyl quinazolin-4(3H)-one/thione derivatives and 1-(7-chloro-4-oxo/-2-phenylquinazoline-3 (4H-yl)) substituted urea derivatives were synthesized and characterised The reaction proceeds through the intermediate 7-chloro-2-phenyl-4H-benzo[d] [1, 3] oxazin-4-one. Synthesized compounds were characterised from infrared (IR), 1H nuclear magnetic resonance (NMR) and mass spectra (m/z) and elemental analysis. By using the agar diffusion cup plate method, tail immersion method, and carrageenan-induced paw oedema method, respectively, the antibacterial, analgesic, and anti-inflammatory efficacy was examined. Based on the screening data of the new quinazoline derivatives, five compounds are found to be effective with antimicrobial activity. Five compounds exhibited good analgesic and anti-inflammatory activity.

Quinazolines are medicinally important as anti-convulsant, anti-cancer, anti-microbial, and anti-tubercular properties etc. They target epidermal growth factor receptors on tumor cells. This work is aimed to synthesize a new series of quinazoline derivatives which could deliver drug specifically to the EGFR over expressing tumors. A series of novel Schiff’s base analogues were developed by in silico screening methods. The drug likeness of the analogues was analyzed by using Molinspiration software. Biological activities of these analogues were evaluated by using PASS software. The candidates which obeyed Lipinski rule of five and having suitable anti-cancer and anti-microbial activity were taken for docking studies using Schrodinger software. All the proposed derivatives were docked with various protein targets obtained from PDB, using GLIDE software and satisfactory docking energy scores were obtained. Selected 10 derivatives of quinazoline have been synthesized by anthranilamide and benzaldehyde as starting materials. These analogues were purified by analyzing its melting point, Rf value. These were further characterized by FT-IR, 1H NMR and MASS spectral studies. The anti-cancer activity of these derivatives was done by MTT assay against HeLa cell lines, LD50 values were calculated by Brine Shrimp Lethality Assay. From these experiments it is clearly revealed that these analogues possess good anti-cancer activity and are good lead compounds against tumors.

Besides control of the fungal plant pathogens, another interesting aspect observed when plants are treated with Trichoderma harzianum include effects such as complete and even stand of plants, improved seed germination, increases in plant height and overall enhanced plant growth. No research has yet been conducted to elucidate the mechanism by which these effects occur. Improved seed germination, in particular, suggest that Trichoderma harzianum produces a metabolite that may mimic the plant growth hormone gibberellic acid. The metabolite gliotoxin, produced by Trichoderma harzianum appear to be structurally most similar to gibberellic acid. In this study, common pharmacophore generation and molecular ligand docking simulations were used to evaluate the molecular similarity between gibberellic acid, specifically GA3, and gliotoxin. For the common pharmacophore evaluation, the structure of various gibberellic acids were used to construct a pharmacophore space to which gliotoxin was aligned, and during the molecular docking simulations the gibberellic acid receptor, GID1, served as ligand target for GA3 and gliotoxin. During the common pharmacophore evaluation, gliotoxin was successfully aligned to the common pharmacophore model constructed from various gibberellic acids. Furthermore, molecular docking simulations of gliotoxin and GA3 into the gibberellic acid receptor (GID1) yielded docking scores of -10.78 kcal/mol for the GA3 molecule from Corina and a docking score of -10.17 kcal/mol for gliotoxin. The docking scores suggest that gliotoxin may be able to competitively occupy the receptor space for gibberellic acid, and as such elicit the similar physiological responses observed in literature.

Oncolytic viruses offer the potential to be transformative in the treatment of cancers through their ability to selectively infect, replicate in and kill tumors whilst able to potently activate the immune system. Their activity can be further augmented through the addition of transgenes leading to tumor selective gene expression. Our proprietary Newcastle Disease virus (NDV) backbone has previously been demonstrated to have broad oncolytic activity whilst inducing potent anti tumor immune effects in preclinical models. We set out to test whether the incorporation of an IL-12 transgene into the NDV backbone could result in transgene dependent enhancement in anti tumor efficacy. In vitro, the addition of IL-12 into the NDV genome did not alter NDV infectivity in tumor or non-cancer cells compared to the backbone virus and infection of cancer cells resulted in the production of bioactive IL-12. In an immune-deficient xenograft model, a single systemic administration of NDVhuIL-12 resulted in tumor selective replication and local IL-12 production within the tumor microenvironment (TME). In syngeneic tumor models, local tumoral administration of NDVmuIL-12 resulted in the generation of an elevated and more durable type II interferon response compared to NDV-GMCSF; though similar pharmacokinetic profiles were observed. This difference in cytokine response correlated with superior single agent efficacy of NDVmuIL-12 compared to NDV alone in the B16F10 model. Furthermore, NDVmuIL-12 demonstrated anti tumor efficacy in several NDV refractory models, suggesting tumor expression of IL-12 was necessary to drive anti tumor activity in some circumstances. Across all models tested significant changes in the tumor immune microenvironment, previously associated with enhanced anti tumor immunity were observed in NDVmuIL-12 tumours compared to backbone virus alone. There is an abundance of pre-clinical data demonstrating that IL-12 can exert potent anti tumor activity, but its clinical application has been hindered through its toxicity when administered systemically. These data provide evidence that recombinant NDV could be utilised to deliver IL-12 to the TME when administered systemically and that the addition of IL-12 potentiates the anti tumor activity of NDV. Citation Format: James Harper, Andrew Leinster, Nicola Rath, Shannon Burke, Kathy Mulgrew, Hong Jin, Robert W. Wilkinson. A recombinant Newcastle disease virus expressing IL-12 has potent pre-clinical immunomodulatory and anti tumor properties [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6535.

BackgroundMalignant melanoma is a deadly type of metastatic skin cancer with increased incidence over the past 30 years. Despite the advanced knowledge on the biology, immunobiology and molecular genetics of melanoma, the alternatives of treatment are limited with poor prognosis. On clinical trials, natural products and among them redox-active quinones have been tested in the attempt to control the growth of cancer cells. Recently, we isolated jacaranone from Pentacalia desiderabilis, a benzoquinone derivative that showed a broad antitumor activity and protective anti-melanoma effect in a syngeneic model. The purified substance is active at micromolar concentrations, is not hemolytic, and is not toxic in naïve mice.Methodology/Principal FindingsThe jacaranone antitumor activity was shown against several human cancer cell lines in vitro. Moreover, the induction of apoptosis in murine melanoma cells and jacaranone antitumor activity in vivo, in a melanoma experimental model, were also shown. Jacaranone renders antiproliferative and proapoptotic responses in tumor cells, by acting on Akt and p38 MAPK signaling pathways through generation of reactive oxygen species (ROS). The free radical scavenger N-acetyl-cysteine (NAC) was able to completely suppress cell death induced by jacaranone as it blocked Akt downregulation, p38 MAPK activation as well as upregulation of proapoptotic Bax. Notably, treatment of melanoma growing subcutaneously in mice with jacaranone significantly extended the mean survival times in a dose-dependent manner.Conclusions/SignificanceThe results provide evidence for the mechanisms of action of jacaranone and emphasize the potential use of this quinone for the treatment of melanoma.

The total alkaloid fraction of the methanolic extract of Solanum pseudocapsicum leaves was tested for its in-vivo antitumor activity against Dalton's Lymphoma Ascites model in mice. The total alkaloid fraction at 2.5 and 5.0 mg/kg body weight doses exhibited antitumor activity as revealed by the significant increase in the mean survival time and the percentage increase in life span of tumor bearing mice. The antitumor activity observed may be due to its cytotoxic properties. However the treatment caused a significant decrease in the body weight below the normal indicating the toxicity of the treatment.

Naphthalimides and analogues as antitumor agents: A review on molecular design, bioactivity and mechanism of action

Cancer is a general name for a group of more than 100 diseases in which cells belonging to a part of the body, begin uncontrolled proliferation. Nowadays, cancer is an important public health problem in all countries. For decades, conventional chemotherapy has been the most common type of anticancer pharmacotherapy. Cancer chemotherapy has been one of the major advances in the field of medicine in the last few decades. However, drugs administered for chemotherapy have a narrow therapeutic index and therefore, there is a high incidence of unwanted side effects. Thiadiazole is a five-membered ring system that has gained prominence by exhibiting a wide variety of biological activities. It has interesting pharmacophores that display a broad spectrum biological activity. The lower toxicity and in vivo stability of 1,3,4-thiadiazole nucleus are attributed to its aromaticity. Thiadiazole has exhibited potential antiglaucoma, antiinflammatory, antitumor, antiulcer, antibacterial, antiviral, analgesic, antiepileptic, antifungal and radioprotective activities. In this review article antitumor activity of various thiadiazole derivatives has been discussed.

Characterization of N,N'-substituted ureas was found to be challenging by nuclear magnetic resonance (NMR) spectroscopy, particularly N-di- and tri-alkylated ureas because of the absence of adjacent protons. In the present study, electrospray ionization tandem mass spectrometry has been used to differentiate positional isomeric pairs and to characterize a series of N,N'-substituted ureas, as these compounds have significant importance for drug discovery. Additionally, urea is an essential functionality in several bioactive compounds as well as a variety of clinically approved therapies. High-resolution electrospray ionization tandem mass spectrometry (ESI-HR-MS/MS) has been used to characterize a series of N,N'-substituted urea derivatives and differentiate two pairs of positional isomers. The data was acquired by Xcaliber application in positive ionization mode. ESI-HR-MS/MS spectra of [M + H]+ ions of the positional isomeric urea derivatives 8a and 8b show distinct fragmentation patterns. For example, the MS/MS spectrum of the [M + H]+ ion of isomer 8a displays the abundant fragment ion at m/z 285.1595, which was totally absent in isomer 8b. This would be plausibly formed by the cleavage of the C-N bond of the urea group with the elimination of the isocyanate moiety. In contrast, the MS/MS spectrum of the [M + H]+ ion of isomer 8b shows an intense ion at m/z 311.1389 which is completely absent in isomer 8a which would be formed by the cleavage of the C-N bond attached to the ring nitrogen. Similarly, another pair of positional isomers, 8c and 8d, have been clearly distinguished by their fragmentation behaviour. In addition, a series of N,N'-substituted urea derivatives were studied to investigate the impact of different substitution on the fragmentation behaviour. The present study demonstrates that ESI-HR-MS/MS can be used to differentiate pairs of N,N'-substituted urea positional isomers and characterize a series of derivatives. It was observed that a characteristic fragment ion was formed by the C-N bond cleavage with the elimination of an isocyanate moiety. The proposed mechanism of fragmentation was supported by the change in the fragmentation pathway upon alkylation of the NH. In order to generalize this fragmentation pattern, a series of N-alkylated ureas was synthesized and studied by MS/MS.

Spectral investigations of 2,5-difluoroaniline by using mass, electronic absorption, NMR, and vibrational spectra

The IFN-gamma-inducible and CXCR3-targeting human CXC chemokines CXCL9 (Mig) and CXCL10 (IP10) have potent antitumor activity through attraction of cytotoxic T lymphocytes and inhibition of angiogenesis. The more recently identified CXCR3-targeting chemokine CXCL11 (I-TAC/IP9) proved to be a more potent chemokine than CXCL9 and CXCL10 in vitro, both in chemotaxis assays with CXCR3+ T lymphocytes and in calcium mobilization experiments. However, its antitumor activity in vivo has not been shown so far. To investigate this, mice were challenged with EL4 T-cell lymphoma cells, genetically modified to produce murine CXCL11. Tumor growth curves showed complete rejection of CXCL11-producing tumors but not of control tumors. Tumor infiltrate analysis by flow cytometry showed a clear correlation between rejection of CXCL11-producing tumors and an increase of tumor-infiltrating CD8+CXCR3+ as well as CD8+CXCR3- T lymphocytes. In vivo CD8 T-cell depletion completely abrogated the antitumor effect. No difference in angiogenesis between control and CXCL11-producing tumors was observed. In survivors, rechallenge experiments with wild-type tumor cells suggested development of protective antitumor immunity involving tumor-specific IFN-gamma production by CD8+ T lymphocytes. These experiments show, for the first time, antitumor activity of CXCL11 in vivo, which warrants exploration for its potential role in anticancer immunotherapy.

Natural products have historically been the most productive source of leads for the development of drugs. Thanks to the chemical methodologies of natural products, a vast array of bioactive secondary metabolites from terrestrial and marine sources has been discovered. Many of these natural products became current drug candidates. Therefore, the research of new biologically active compounds through structure elucidation and biological tests is the central issue of these studies. My research is placed in this field and it has been mainly devoted to the discovery and to the chemical and pharmacological investigation of new bioactive natural products as “lead compounds” in the antitumor and antimalarial activities area. My work, described in this PhD thesis, was organized in two different topics: i) isolation and structural characterization of bioactive secondary metabolites from marine invertebrates, ii) synthesis of thiazinoquinones derivatives endowed with cytotoxic and antiplasmodial activities from marine natural metabolites. The achievement of my research project required isolation and extraction procedures. The chemical characterization of the isolated compounds has been performed through an extensive spectroscopic analysis (UV, IR, ECD, 1D and 2D NMR) together with mass spectrometry, computational and electrochemistry methods. I have also used synthetic methods both for the chemical derivatization of the isolated molecules and for the preparation of analogues on the simplified model of natural molecules. During the course of my PhD research, whose results are reported in the following thesis, I have been dealing with the extraction and the chemical re-investigation of a new collection of the Mediterranean ascidian Phallusia fumigata. This analysis led to the isolation of one sulfated sterol, phallusiasterol C, which is a possible modulator of the PXR nuclear receptor. Morover, I have been strongly involved in completing the stereochemistry assignment of phosphoeleganin, a complex acyclic marine natural product, isolated previously from the Mediterranean ascidian Sidnyum elegans. In addition, the electrochemical response of four natural cytotoxic thiazinoquinones, beforehand isolated and characterized from Aplidium species, has been investigated, in order to clarify the mechanism of action which is the basis of their cytotoxicity. The research for new antiplasmodial hits is another main topic of my PhD activity discussed in this thesis. Previously, having identified the thiazinoquinone nucleus as new active chemiotype against P. falciparum, my research started from the development of two new series of methoxy and amide derivatives inspired by two marine metabolites isolated from the Mediterranean ascidian Aplidium conicum. Recently, in order to refine this pharmacophore model and improve the pharmacokinetic and pharmacodynamic properties, I have performed a rational design and synthesis of new modified analogues with simplified side chains and different substituents. In collaboration with the Department of Biomedical, Surgical and Dental sciences (University of Milan), the synthetic analogues of natural quinones have been tested for their in vitro antiplasmodial activity against both chloroquine (CQ)-sensitive (D10) and -resistant (W2) strains of P. falciparum, although some of them were strongly cytotoxic. Some of the synthetic derivatives showed significant antiplasmodial activity together with some important structural requirements. Additionally, in order to rationalize the structure-activity relationships (SARs), an integrated approach based on computational and electrochemistry studies was performed. These studies were carried out by a further collaborating external research group. The above results clearly evidence that quinone natural products represent an excellent source of novel “drug-like” small molecules for drug discovery in antimalarial research.