Synthesis, X-ray crystallography, computational investigation on quinoxaline derivatives as potent against adenosine receptor A2AAR.

Quinoxaline represents one of the most important classes of heterocyclic compounds, which have exhibited a wide range of biological activities and industrial importance in many different fields. In this regard, we have synthetized two new quinoxaline derivatives. Their structures were confirmed by single-crystal X-ray analysis. The compounds show potent activity against adenosine receptors A2AAR based on structural activity relationship studies. Further molecular docking, molecular dynamics, ADMET analysis, and DFT (density functional theory) calculations were performed to understand the titled compound's future drug candidacy. DFT computations confirmed the good stability of the synthesized compounds, as evidenced by the optimized molecular geometry, HOMO-LUMO energy gap, and intermolecular interactions. NBO analysis confirmed intermolecular interactions mediated by lone pair, bonding, and anti-bonding orbitals. All DFT findings were consistent with experimental results, indicating that the synthesized molecules are highly stable. These findings suggest that the synthesized compounds are promising candidates for further development as drugs for the treatment of A2AAR-related diseases.Communicated by Ramaswamy H. Sarma.

Ionophore-Based Polymeric Sensors for Potentiometric Assay of the Anticancer Drug Gemcitabine in Pharmaceutical Formulation: A Comparative Study.

Gemcitabine is a chemotherapeutic agent used to treat various malignancies, including breast and bladder cancer. In the current study, three innovative selective gemcitabine hydrochloride sensors are developed using 4-tert-butylcalix-[8]-arene (sensor 1), ß-cyclodextrin (sensor 2), and γ-cyclodextrin (sensor 3) as ionophores. The three sensors were prepared by incorporating the ionophores with o-nitrophenyl octyl ether as plasticizer and potassium tetrakis(4-chlorophenyl) borate as ionic additive into a polyvinyl chloride polymer matrix. These sensors are considered environmentally friendly systems in the analytical research. The linear responses of gemcitabine hydrochloride were in the concentration range of 6.0 × 10-6 to 1.0 × 10-2 mol L-1 and 9.0 × 10-6 to 1.0 × 10-2 mol L-1 and 8.0 × 10-6 to 1.0 × 10-2 mol L-1 for sensors 1, 2, and 3, respectively. Over the pH range of 6-9, fast-Nernst slopes of 52 ± 0.6, 56 ± 0.3, and 55 ± 0.8 mV/decade were found in the same order with correlation regressions of 0.998, 0.999, and 0.998, respectively. The lower limits of detection for the prepared sensors were 2.5 × 10-6, 2.2 × 10-6, and 2.7 × 10-6 mol L-1. The sensors showed high selectivity and sensitivity for gemcitabine. Validation of the sensors was carried out in accordance with the requirements established by the IUPAC, while being inexpensive and easy to use in drug formulation. A statistical analysis of the methods in comparison with the official method showed that there was no significant difference in accuracy or precision between them. It was shown that the new sensors could selectively and accurately find gemcitabine hydrochloride in bulk powder, pharmaceutical formulations, and quality control tests. The ionophore-based sensor shows several advantages over conventional PVC membrane sensor sensors regrading the lower limit of detection, and higher selectivity towards the target ion.

Biological Investigation of 2-Thioxo-benzo[g]quinazolines against Adenovirus Type 7 and Bacteriophage Phi X174: An In Vitro Study.

Mortality and morbidity caused by viruses are a global health problems. Therefore, there is always a need to create novel therapeutic agents and refine existing ones to maximize their efficacy. Our lab has produced benzoquinazolines derivatives that have proven effective activity as antiviral compounds against herpes simplex (HSV 1 and 2), coxsackievirus B4 (CVB4), and hepatitis viruses (HAV and HCV). This in vitro study was aimed at investigating the effectiveness of benzoquinazoline derivatives 1-16 against adenovirus type 7 and bacteriophage phiX174 using a plaque assay. The cytotoxicity against adenovirus type 7 was also performed in vitro, using a MTT assay. Most of the compounds exhibited antiviral activity against bacteriophage phiX174. However, compounds 1, 3, 9, and 11 showed statistically significant reductions of 60-70% against bacteriophage phiX174. By contrast, compounds 3, 5, 7, 12, 13, and 15 were ineffective against adenovirus type 7, and compounds 6 and 16 had remarkable efficacy (50%). Using the MOE-Site Finder Module, a docking study was carried out in order to create a prediction regarding the orientation of the lead compounds (1, 9, and 11). This was performed in order to investigate the activity of the lead compounds 1, 9, and 11 against the bacteriophage phiX174 by locating the ligand-target protein binding interaction active sites.

Significant pharmacological activities of benzoquinazolines scaffold.

Benzoquinazolines, the essential constituents of numerous well-known heterocyclic systems, have occupied a prominent position and played a significant part in the synthesis of various pharmaceutical compounds. The wide range of pharmacological effects attributed to benzoquinazolines has been the subject of extensive study. These include their roles as anticancer, antimicrobial, anti-monoamine oxidase, anticonvulsant, antiviral, antinociceptive, antioxidant, antineoplastic, antituberculosis, antiplatelet, and antiphlogistic agents. This work provides an attempt at a literature review of the pharmacological activities of benzoquinazoline derivatives, including an up-to-date account of recent research findings, and suggests avenues for future exploration in the pursuit of more potent and specific analogues for a wide range of biological targets using this platform.

Thermodynamic and Computational (DFT) Study of Non-Covalent Interaction Mechanisms of Charge Transfer Complex of Linagliptin with 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and Chloranilic acid (CHA).

This study describes the non-covalent interactions of the charge transfer complex (CT), which was responsible for the synthesis of Linagliptin (LNG) with 2,3-Dichloro-5,6-Dicyano-1,4-benzoquinone (DDQ), or with Chloranilic acid (CHA) complexes in acetonitrile (MeCN) at temperatures of (25 ± 2 °C). Then, a UV-Vis spectrophotometer was utilized to identify Linagliptin (LNG) from these complexes. For the quantitative measurement of Linagliptin in bulk form, UV-Vis techniques have been developed and validated in accordance with ICH criteria for several aspects, including selectivity, linearity, accuracy, precision, LOD, LOQ, and robustness. The optimization of the complex synthesis was based on solvent polarization; the ratio of molecules in complexes; the association constant; and Gibbs energy (ΔG°). The experimental work is supported by the computational investigation of the complexes utilizing density functional theory as well as (QTAIM); (NCI) index; and (RDG). According to the optimized conditions, Beer's law was observed between 2.5-100 and 5-100 µM with correlation coefficients of 1.9997 and 1.9998 for LGN-DDQ and LGN-CHA complexes, respectively. For LGN-DDQ and LGN-CHA complexes, the LOD and LOQ were (1.0844 and 1.4406 µM) and (3.2861 and 4.3655 µM), respectively. The approach was successfully used to measure LGN in its bulk form with high precision and accuracy.

Chemical Composition, Antioxidant and Antibacterial Activities of Thymus broussonetii Boiss and Thymus capitatus (L.) Hoffmann and Link Essential Oils.

Thymus capitatus and Thymus broussonnetii are two Moroccan endemic medicinal plants used traditionally by the local population. The present study aims to investigate their essential oil chemical composition, antioxidant and antibacterial activities. The chemical composition of the essential oils was determined using the GC-MS analysis, the antioxidant activity assessed using DPPH and FRAP methods while the antimicrobial activity was evaluated against nine bacteria species tested (Enterococcus faecalis, Serratia fonticola, Acinetobacter baumannii, Klebsiella oxytoca, sensitive Klebsiella pneumoniae, sensitive Escherichia coli, resistant Escherichia coli, resistant Staphylococcus aureus and Enterobacter aerogenes). The major identified compounds of T. capitatus essential oil where carvacrol (75%) and p-cymene (10.58%) while carvacrol (60.79%), thymol (12.9%), p-cymene (6.21%) and γ-terpinene (4.47%) are the main compounds in T. broussonnetii essential oil. The bioactivity of the essential oils of the two species of thyme was explained by their richness in oxygenated monoterpenes known for their great effectiveness with an IC50 of 3.48 ± 0.05 and 4.88 ± 0.04 µL/mL and EC50 of 0.12 ± 0.01 and 0.20 ± 0.02 µL/mL in the DPPH and FRAP assays, respectively, with an important antibacterial activity. These results encourage the use of these plants as a source of natural antioxidants, and antibacterial additives, to protect food from oxidative damage and to eliminate bacteria that are responsible for nosocomial infections.

Artemisia absinthium L. Aqueous and Ethyl Acetate Extracts: Antioxidant Effect and Potential Activity In Vitro and In Vivo against Pancreatic α-Amylase and Intestinal α-Glucosidase.

Artemisia absinthium L. is one of the plants which has been used in folk medicine for many diseases over many centuries. This study aims to analyze the chemical composition of the Artemisia absinthium ethyl acetate and its aqueous extracts and to evaluate their effect on the pancreatic α-amylase enzyme and the intestinal α-glucosidase enzyme. In this study, the total contents of phenolic compounds, flavonoids, and condensed tannins in ethyl acetate and the aqueous extracts of Artemisia absinthium leaves were determined by using spectrophotometric techniques, then the antioxidant capacity of these extracts was examined using three methods, namely, the DPPH (2, 2-diphenyl-1picrylhydrazyl) free radical scavenging method, the iron reduction method FRAP, and the ß-carotene bleaching method. The determination of the chemical composition of the extracts was carried out using high-performance liquid chromatography-the photodiode array detector (HPLC-DAD). These extracts were also evaluated for their ability to inhibit the activity of the pancreatic α-amylase enzyme, as well as the intestinal α-glucosidase enzyme, in vitro and in vivo, thus causing the reduction of blood glucose. The results of this study showed that high polyphenol and flavonoid contents were obtained in ethyl acetate extract with values of 60.34 ± 0.43 mg GAE/g and 25.842 ± 0.241 mg QE/g, respectively, compared to the aqueous extract. The results indicated that the aqueous extract had a higher condensed tannin content (3.070 ± 0.022 mg EC/g) than the ethyl acetate extract (0.987 ± 0.078 mg EC/g). Ethyl acetate extract showed good DPPH radical scavenging and iron reduction FRAP activity, with an IC50 of 0.167 ± 0.004 mg/mL and 0.923 ± 0.0283 mg/mL, respectively. The ß-carotene test indicated that the aqueous and ethyl acetate extracts were able to delay the decoloration of ß-carotene with an inhibition of 48.7% and 48.3%, respectively, which may mean that the extracts have antioxidant activity. HPLC analysis revealed the presence of naringenin and caffeic acid as major products in AQE and EAE, respectively. Indeed, this study showed that the aqueous and ethyl acetate extracts significantly inhibited the pancreatic α-amylase and intestinal α-glucosidase, in vitro. To confirm this result, the inhibitory effect of these plant extracts on the enzymes has been evaluated in vivo. Oral intake of the aqueous extract significantly attenuated starch- and sucrose-induced hyperglycemia in normal rats, and evidently, in STZ-diabetic rats as well. The ethyl acetate extract had no inhibitory activity against the intestinal α-glucosidase enzyme in vivo. The antioxidant and the enzyme inhibitory effects may be related to the presence of naringenin and caffeic acid or their synergistic effect with the other compounds in the extracts.

An overview of triazoloquinazolines: Pharmacological significance and recent developments.

Nitrogen heterocyclic rings have participated to constitute most of the drugs and several pharmacologically related compounds. The existence of such hetero atoms/groups in heterocyclic systems privileged specificities in their biological objectives. Particularly, quinazoline and triazole are biologically imperative platforms known to be linked with various pharmacological activities. Some of the prominent pharmacological responses ascribed to these systems are analgesic, antiinflammatory, anticonvulsant, hypnotic, antihistaminic, antihypertensive, anticancer, antimicrobial, antitubercular, antiviral and antimalarial activities. This diversity in the pharmacological outputs for both triazole and quinazoline systems has encouraged the medicinal chemistry researchers to create several chemical routes aiming at the incorporation of two rings in one molecule named triazoloquinazoline system. This system has shown multiple potential activities against numerous targets. Correlation the specific structural features of triazoloquinazoline system with its pharmacological purposes has successively been achieved by performing several pharmacological examinations and structure-activity relationship studies. The development of triazoloquinazoline derivatives and the understanding of their pharmacological targets offer opportunities for novel therapeutics. This review mainly emphases on the medicinal chemistry aspects of triazoloquinazolines including synthesis, reactivity, biological activity and structure activity relationship studies (SARs). Moreover, this review collates literature reported by researchers on triazoquinazolines and provides detailed attention on their analogs pharmacological activities in the perspective of drug development and discovery.

Antiproliferative and Antiangiogenic Properties of New VEGFR-2-targeting 2-thioxobenzo[g]quinazoline Derivatives (In Vitro).

A series of 3-ethyl(methyl)-2-thioxo-2,3-dihydrobenzo[g]quinazolines (1-17) were synthesized, characterized, and evaluated in vitro for their antiangiogenesis VEGFR-2-targeting, antiproliferative, and antiapoptotic activities against breast MCF-7 and liver HepG2 cells. Flow cytometry was used to determine cancer-cell cycle distributions, and apoptosis was detected using annexin-V-FITC (V) and propidium iodide (PI) dyes. Fluorescence microscopy, in combination with Hoechst staining was used to detect DNA fragmentation. Most of the tested benzo[g]quinazolines demonstrated promising activity (IC50 = 8.8 ± 0.5-10.9 ± 0.9 µM) and (IC50 = 26.0 ± 2.5-40.4 ± 4.1 µM) against MCF-7 and HepG2, respectively. Doxorubicin was used as a reference drug. Compounds 13-15 showed the highest activity against both cancer cell lines. Differential effects were detected by cell-cycle analysis, indicating similarities in the actions of 13 and 14 against both MCF7 and HepG2, involving the targeting of G1 and S phases, respectively. Compound 15 showed similar indices against both cells, indicating that its cytotoxicity toward the examined cancer cells could be unselective. Interestingly, 14 and 15 showed the highest apoptosis (30.76% and 25.30%, respectively) against MCF-7. The DNA fragmentation results agreed well with the apoptosis detected by flow cytometry. In terms of antiangiogenesis activity, as derived from VEGFR-2 inhibition, 13 and 15 were comparable to sorafenib and effected 1.5- and 1.4-fold inhibition relative to the standard sorafenib. A docking study was conducted to investigate the interaction between the synthesized benzo[g]quinazolines and the ATP-binding site within the catalytic domain of VEGFR-2.

Exploiting the 4-hydrazinobenzoic acid moiety for the development of anticancer agents: Synthesis and biological profile.

Thirteen 4-hydrazinobenzoic acid derivatives were elaborated and characterized by spectral analyses (NMR and MS). Evaluation of their in vitro cytotoxic activity showed that some of the targets demonstrated potent inhibitory effects against HCT-116 and MCF-7 cancer cells. The IC50 values ranged between 21.3 ± 4.1 and 28.3 ± 5.1 µM, respectively, whereas those of doxorubicin (reference drug) ranged between 22.6 ± 3.9 and 19.7 ± 3.1 µM, respectively. The active targets 6, 7 and 9 exhibited very weak cytotoxicity on normal cells (RPE-1) and showed higher IC50 values against HCT-116 and MCF-7 cells in comparison to doxorubicin. Furthermore, compounds 7, 9 and 10 inhibited the proliferation of MCF-7 by the induction of apoptosis. The bioassay results in the regression plots generated in 3D QSAR models were in agreement and correlated with the anticancer results of the target molecules. The 4-hydazinobenzoic acid derivatives can be used as cornerstones for further structural modifications as future anticancer agents.

Evaluation of Cytotoxic and Tyrosinase Inhibitory Activities of 2-phenoxy(thiomethyl) pyridotriazolopyrimidines: In Vitro and Molecular Docking Studies.

BACKGROUND: The use of tyrosinase has confirmed to be the best means of recognizing safe, effective, and potent tyrosinase inhibitors for whitening skin. Twenty-four 2-phenoxy(thiomethyl)pyridotriazolopyrimidines were synthesized and characterized in our previous studies. OBJECTIVE: The present work aimed to evaluate their cytotoxicity against HepG2 (hepatocellular carcinoma), A549 (pulmonary adenocarcinoma), MCF-7 (breast adenocarcinoma) and WRL 68 (embryonic liver) cell lines. METHODS: MTT assay was employed to investigate the cytotoxicity, and a tyrosinase inhibitor screening kit was used to evaluate the Tyrosinase (TYR) inhibitory activity of the targets. RESULTS: The tested compounds exhibited no considerable cytotoxicity, and nine of them were selected for a tyrosinase inhibitory test. Compounds 2b, 2m, and 5a showed good inhibitory percentages against TYR compared to that of kojic acid (reference substance). Molecular docking was performed to rationalize the Structure-Activity Relationship (SAR) of the target pyridotriazolopyrimidines and analyze the binding between the docked-selected compounds and the amino acid residues in the active site of tyrosinase. CONCLUSION: The target pyridotriazolopyrimidines were identified as a new class of tyrosinase inhibitors.

Development and validation of a UPLC-MS/MS method for determination of motesanib in plasma: Application to metabolic stability and pharmacokinetic studies in rats.

Motesanib is a potent angiokinase inhibitor, has shown potential therapeutic effects against various cancers. An accurate, reproducible, rapid, specific, sensitive, and valid ultraperformance liquid chromatography-tandem mass spectrometry method was established to quantify motesanib in rat plasma. Motesanib and linifanib (used as an internal standard; IS) were extracted from plasma by liquid-liquid extraction using tert-butyl methyl ether as extracting agent. Chromatographic separation was performed on Acquity™ UPLC BEH™ C18 column (100 mm × 2.1 mm i.d., 1.7 µm; Waters Corp., USA) using a mobile phase comprising of 0.1% formic acid acetonitrile: ammonium acetate (90:10 v/v) eluted at a flow rate of 0.25 mL/min. The electrospray ionization in the positive-mode was used for sample ionization. In the multiple reaction monitoring mode, motesanib and the IS were quantified using precursor-to-product ion transitions of m/z 374.03 → 212.02 and m/z 376.05 → 251.05, respectively. The ranges of the calibration curves were 5.0-1000.0 ng/mL with coefficient of determination of ≥0.998. The method was validated by following recently implemented USFDA guideline for bioanalytical method validation. The lower limit of quantification was 5.0 ng/mL, whereas the intra-day and inter-day accuracies of quality controls (QCs) samples were ranged between 88.91% to 95.65% and 90.20% to 102.17%, respectively. In addition, the linearity, recovery, precision, and stability parameters were found to be within the acceptable range. The method was applied successfully to in vitro microsomal metabolic stability and preliminary oral pharmacokinetic studies in rats. The applied UPLC/MS/MS method was found to be adequately sensitive and therefore suitable for application in routine motesanib pharmacokinetic studies.

Synthesis and biological evaluation of 4-(1H-1,2,4-triazol-1-yl)benzoic acid hybrids as anticancer agents.

A series of 4-(1H-1,2,4-triazol-1-yl)benzoic acid hybrids (1-17) was successfully synthesized and their structures were established by NMR and MS analysis. In vitro cytotoxic evaluation indicated that some of the hybrids exhibited potent inhibitory activities against MCF-7 and HCT-116 cancer cell lines, with IC50 values ranging from 15.6 to 23.9 µM, compared with reference drug doxorubicin (19.7 and 22.6 µM, respectively). Notably, the most potent compounds, 2, 5, 14, and 15, not only exhibited an obvious improvement in IC50 values, but demonstrated very weak cytotoxic effects toward normal cells (RPE-1) compared with doxorubicin. A further investigation showed that compounds 2 and 14 clearly inhibited the proliferation of MCF-7 cancer cells by inducing apoptosis. In addition, these hybrids showed acceptable correlation with bioassay results in regression plots generated by 2D QSAR models. Our results indicated that 1,2,4-triazole benzoic acid hybrids could be used as a structural optimization platform for the design and development of more selective and potent anticancer molecules.

Radioiodination and biodistribution of newly synthesized 3-benzyl-2-([3-methoxybenzyl]thio)benzo[g]quinazolin-4-(3H)-one in tumor bearing mice.

3-Benzyl-2-((3-methoxybenzyl)thio)benzo[g]quinazolin-4(3H)-one was previously synthesized and proved by physicochemical analyses (HRMS, 1H and 13C NMR). The target compound was examined for its radioactivity and the results showed that benzo[g]quinazoline was successfully labeled with radioactive iodine using NBS via an electrophilic substitution reaction. The reaction parameters that affected the labeling yield such as concentration, pH and time were studied to optimize the labeling conditions. The radiochemical yield was 91.2 ±â€¯1.22% and the in vitro studies showed that the target compound was stable for up to 24 h. The thyroid was among the other organs in which the uptake of 125I-benzoquinazoline has increased significantly over the time up to 4.1%. The tumor uptake was 6.95%. Radiochemical and metabolic stability of the benzoquinazoline in vivo/in vitro and biodistribution studies provide some insights about the requirements for developing more potent radiopharmaceutical for targeting the tumor cells.

Quantum Chemical Calculations and Statistical Analysis: Structural Cytotoxicity Relationships of some Synthesized 2-thiophen-naphtho(benzo)oxazinone Derivatives.

Twenty-two 2-thiophen-naphtho(benzo)oxazinone derivatives are prepared using 3-amino-2-naphthoic and 5-nitroanthranilic acids as building blocks. The target compounds (1-22) were evaluated quantitatively for their cytotoxic effects in vitro against three cancer cell lines, including the lung A549, the hepatocyte HepG2, and the breast MCF-7 carcinoma cells. Compounds 1, 12, 14, and 21 were found to exhibit remarkable cytotoxicity against the tested cancer cell lines. Compound 21 has shown the highest activity against A549 and MCF-7 (IC50: 9.8 & 3.6 µg mL-1) whereas 1 (IC50: 5.9 µg mL-1) and 5 (3.6 µg mL-1) were the most active against HepG2. To elucidate the structure-cytotoxicity relationships of the synthesized compounds, a number of their chemical descriptors are determined including electronic, steric and hydrophobicity descriptors. The electronic properties were calculated through density functional theory (DFT) calculations at the B3LYP/6-31 + G(d,p). The impact of the chosen descriptors is evaluated statistically through simple and multiple linear regression analyses (SLR and MLR). SLR analyses reveal that the impact of each descriptor on the cell lines are relatively weak except for MCF-7, where hardness and softness show moderate correlations with correlation coefficients higher than 60%. The correlations were improved by considering MLR analyses (R2 ≥ 90%), which showed that the cytotoxicity of synthesized compounds is correlated with their combined descriptors hardness, softness, electrophiliciy and hydrophobicity (LogP).

Synthesis and anticancer activity of new quinazoline derivatives.

In this study, a new series of quinazoline derivatives (3-26) was synthesized and characterized via physicochemical and spectral means. Treatment of 2-amino-5-methylbenzoic acid with butyl isothiocyanate resulted in the new 2-thioxoquinazolin-4-one (3). Alkylation and hydrazinolysis of the inherent thioxo group in (1-3) afforded the corresponding thioethers (4-23) and hydrazine derivatives (24 and 25), then 24 was further transformed into tricyclic derivative 26 via cyclocondensation reaction. Compounds 1 and 2, which were previously synthesized, were found to exhibit anticancer activity. The cytotoxicity of all compounds was evaluated in vitro against the HeLa and MDA-MB231 cancer cell lines, including 1 and 2 for comparison, using MTT assay. The treatment of the cells was performed with the synthesized compounds and gefitinib at 0, 1, 5, 10, 25, and 50 µM and incubated for 24 h in 50% DMSO. The IC50 values of the target compounds were reported in µM, using gefitinib as a standard. Our results indicated that all compounds exhibited significant in vitro cytotoxicity against both cell lines. While compounds 1-3 showed good activity, compounds 21-23 were found to be more potent than gefitinib. Thus, compounds 21-23 may be potential anticancer agents, with IC50 values ranging from 1.85 to 2.81 µM in relation to gefitinib (IC50 = 4.3 and 28.3 µM against HeLa and MDA-MB231 cells, respectively).

Cytotoxicity evaluation of a new set of 2-aminobenzo[de]iso-quinoline-1,3-diones.

A new series of 2-amino-benzo[de]isoquinoline-1,3-diones was synthesized and fully characterized in our previous paper. Here, their cytotoxic effects have been evaluated in vitro in relation to colon HCT-116, hepatocellular Hep-G2 and breast MCF-7 cancer cell lines, using a crystal violet viability assay. The IC50-values of the target compounds are reported in µg/mL, using doxorubicin as a reference drug. The findings revealed that compounds 14, 15, 16, 21 and 22 had significant cytotoxic effects against HCT-116, MCF-7 and Hep-G2 cell lines. Their IC50 values ranged between 1.3 and 8.3 µg/mL in relation to doxorubicin (IC50 ≈ 0.45-0.89 µg/mL). Therefore, these compounds could be used as templates for furthering the development and design of more potent antitumor agents through structural modification.

Cytotoxicity and anti-inflammatory activity of methylsulfanyl-triazoloquinazolines.

A series of twenty five 2-methylsulfanyl-[1,2,4]triazolo[1,5-a]quinazoline derivatives 1-25 was previously synthesized. We have now investigated their cytotoxic effects against hepatocellular Hep-G2 and colon HCT-116 carcinoma cells and effect on the macrophage growth, in addition to their influence of the inflammatory mediators [nitric oxide (NO), tumor necrosis factor-α (TNF-α), prostaglandin E-2 (PGE-2) and in bacterial lipopolysachharide (LPS)-stimulated macrophages]. The findings revealed that compounds 13 and 17 showed the highest cytotoxicity and that 3, 6-8 and 25 are promising multi-potent anti-inflammatory agents.

A new series of 2-alkoxy(aralkoxy)-[1,2,4]triazolo[1,5-a]quinazolin-5-ones as adenosine receptor antagonists.

This research was carried out to study the pharmacological activity of a newly synthesized series of 2-alkoxy-[1,2,4]triazolo[1,5-a]quinazolin-5-ones as adenosine receptor antagonists. These compounds have been tested in radioligand binding assays on cloned Chinese hamster ovary (CHO) cells transfected with A(1), A(2A), A(2B) and A(3) receptors. In particular, among the triazoloquinazolines (1-11), the dialkoxy derivative (7b) was found to have the highest affinity at A(1) subtype receptor, and its radioligand binding activity together with 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) was studied. Finally, the structure-activity relationship (SAR) studies on the titled compounds provide some new insights about steric hindrance and lipophilic requirements for anchoring to the adenosine receptors recognition site.