Synthesis and oxidant properties of novel (5-bromobenzofuran-2-yl)(3-methyl-3-mesitylcyclobutyl)ketonethiosemicarbazone

Indane-1,3-Dione: From Synthetic Strategies to Applications

Indane-1,3-dione is a versatile building block used in numerous applications ranging from biosensing, bioactivity, bioimaging to electronics or photopolymerization. In this review, an overview of the different chemical reactions enabling access to this scaffold but also to the most common derivatives of indane-1,3-dione are presented. Parallel to this, the different applications in which indane-1,3-dione-based structures have been used are also presented, evidencing the versatility of this structure.

Synthesis, in vitro urease inhibitory potential and molecular docking study of benzofuran-based-thiazoldinone analogues

In continuation of our work on enzyme inhibition, the benzofuran-based-thiazoldinone analogues (1-14) were synthesized, characterized by HREI-MS, 1H and 13CNMR and evaluated for urease inhibition. Compounds 1-14 exhibited a varying degree of urease inhibitory activity with IC50 values between 1.2 ± 0.01 to 23.50 ± 0.70 µM when compared with standard drug thiourea having IC50 value 21.40 ± 0.21 µM. Compound 1, 3, 5 and 8 showed significant inhibitory effects with IC50 values 1.2 ± 0.01, 2.20 ± 0.01, 1.40 ± 0.01 and 2.90 ± 0.01 µM respectively, better than the rest of the series. A structure activity relationship (SAR) of this series has been established based on electronic effects and position of different substituents present on phenyl ring. Molecular docking studies were performed to understand the binding interaction of the compounds.

Understanding the chemistry behind the antioxidant activities of butylated hydroxytoluene (BHT): a review

Hindered phenols find a wide variety of applications across many different industry sectors. Butylated hydroxytoluene (BHT) is a most commonly used antioxidant recognized as safe for use in foods containing fats, pharmaceuticals, petroleum products, rubber and oil industries. In the past two decades, there has been growing interest in finding novel antioxidants to meet the requirements of these industries. To accelerate the antioxidant discovery process, researchers have designed and synthesized a series of BHT derivatives targeting to improve its antioxidant properties to be having a wide range of antioxidant activities markedly enhanced radical scavenging ability and other physical properties. Accordingly, some structure-activity relationships and rational design strategies for antioxidants based on BHT structure have been suggested and applied in practice. We have identified 14 very sensitive parameters, which may play a major role on the antioxidant performance of BHT. In this review, we attempt to summarize the current knowledge on this topic, which is of significance in selecting and designing novel antioxidants using a well-known antioxidant BHT as a building-block molecule. Our strategy involved investigation on understanding the chemistry behind the antioxidant activities of BHT, whether through hydrogen or electron transfer mechanism to enable promising anti-oxidant candidates to be synthesized.

Green and One-Pot Electrochemical Synthesis of New Benzofurans Based on an ECC Mechanism

The electrochemical oxidation of quinizarine has been studied in the presence of methyl cyanoacetate and ethyl cyanoacetate acting as a nucleophile in acetate buffer solution mixed with ethanol (30/70 v/v) using cyclic voltammetry and controlled-potential coulometry methods. The results revealed that anthracene-1,4,9,10-tetraone derived from the electro-oxidation of quinizarin participates in 1,4-Michael addition reactions with cyanoacetate derivatives. The adducts formed convert to the corresponding benzofuran derivatives through an ECC (Electrochemical, Chemical, Chemical reaction) mechanism. In the present study, benzofuran derivatives were synthesised in good yields using controlled potential electro-oxidation at three graphite electrode in an undivided cell under mild conditions.

Synthesis, Structure and Antioxidant Activity of (Tetra-O-acetyl-β-D-galactopyranosyl)thiosemicarbazones of Substituted Benzaldehydes

Some new substituted benzaldehyde (2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl) thiosemicarbazones were synthesised by reaction of 2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl thiosemicarbazide and different substituted benzaldehydes. The reaction was performed using conventional and microwave-assisted heating methods. The structures of thiosemicarbazones were confirmed by spectroscopic (IR, (1) H NMR, (13) C NMR and MS) method. The antioxidant activity of these thiosemicarbazones was evaluated, in vitro and in vivo, and it's shown that some of these compounds had significant antioxidant activity.

Novel transition metal complexes of 4-hydroxy-coumarin-3-thiocarbohydrazone: pharmacodynamic of Co(III) on rats and antimicrobial activity

A new series of stable transition metal complexes of the formula M(L)X·S, where M = Cu(II), Ni(II), Co(III), Cr(III) and Fe(III) and L is the deprotonated ligand of 4-hydroxy-coumarin-3-thiocarbohydrazone, X = Cl(-), NO(3)(-) or CH(3)COO(-) and S = H(2)O and/or EtOH. The HL ligand was prepared by the reaction of 3-formyl-4-hydroxy-coumarine with thiocarbohydrazide in the molar ratio 1:1. The HL ligand and its metal complexes were characterized by elemental analysis, (1)H NMR, IR and electronic spectra, and molar conductance and magnetic measurements and thermal gravimetric analysis (TGA). The HL ligand acts as a monobasic tridentate ONS donor in all metal complexes, and coordinated through the phenolic OH, azomethine nitrogen and thione sulfur. Electronic spectra with magnetic moments suggested varieties of geometries around the central metal atoms. Thermal gravimetric analysis indicates that the complexes are stable up to 300°C, and release the uncoordinated and/or coordinated H(2)O/solvent molecules, which is accompanied by a color change. The formed complexes after releasing the solvent were investigated and their structures are suggested to have square planar or octahedral arrangement. Pharmacodynamic of cobalt(III) complex on some biochemical parameters and histological studies in serum and heart tissue in rats have been studied. Although the complexes demonstrated a significant effect at low dose than the high dose, the ligand showed significant good effects in both high and low doses on the biochemical analysis in serum and heart tissue. Cobalt complex was screened in order to evaluate its antifungal activity against the filamentous fungi Aspergillus niger, Aspergillus fumigatus, and Aspergillus flavus, and antibacterial activity against the Candida albicans, Escherichia coli, Klebseilla pneumoniae and Pseudomonas aeruginosa.

Thiosemicarbazone derivate protects from AAPH and Cu2+ -induced LDL oxidation

AIMS

Several lines of evidence support the hypotheses that the oxidation of low density lipoprotein (LDL) may play a crucial role in the initiation and progression of atherosclerosis. Oxidative stress is one of the causes of the overproduction of reactive species that increase the formation of oxidized LDL. Thiosemicarbazones are compounds used in anticancer, antiviral and antifungal therapy; however, its redox activity has been controversial. Thus, we tested, in vitro, a possible antioxidant activity of a thiosemicarbazone derivate, the isatin-3-N(4)-benzilthiosemicarbazone (IBTC).

MAIN METHODS

We measured the conjugated diene formation in serum and LDL as well as the loss of tryptophan fluorescence in LDL induced by two oxidant agents, 2,2-azobis(2-amidinopropane dihydrochloride) (AAPH) and Cu(2+). Thiobarbituric acid reactive substances (TBARS) formation in LDL and in different rat tissues was also assessed. The toxicity of IBTC was measured using aortic slices viability assay.

KEY FINDINGS

Our results show that IBTC significantly reduced the AAPH and Cu(2+)-induced formation of conjugated dienes, increased in a dose-dependent manner the lag phase and the t(1/2) of tryptophan fluorescence, and reduced the TBARS formation in LDL, plasma and rat tissues, showing no toxicity to aortic slices.

SIGNIFICANCE

These results indicate that IBTC is a good antioxidant and a promising antiatherogenic agent for further studies in vivo.

Effect of 3-(1H-Pyrrol-2-yl)-1H-indazole on the antioxidant status of rats

The influence of injection periods of 3-(1H-pyrrol-2-yl)-1H-indazole regarding vitamins A, E, C, selenium (Se), malondialdehyde (MDA) levels, and glutathione peroxidase (GSH-Px) activity in rats has been investigated. The substance was given by subcutaneous injection at 20 mg/kg every other day for a total of 15 injections. At the end of the treatment, Se levels in serum were determined by fluorimetry, and those of vitamins A, E, C, and malondialdehyde in serum, liver, and kidney were determined by high-performance liquid chromatography. GSH-Px activities in erythrocytes were determined spectrophotometrically. Vitamins A, E, C, and Se levels were generally lower than in the controls, while GSH-Px activity at the third injection period was maximally increased, with the activities after the other injection periods being higher than in the control group. In addition, vitamins A, E, and C levels were generally lower than the control groups, while serum, liver, and kidney MDA levels gradually increased depending on injection periods. On the other hand, GSH-Px activity was higher than in the control group. Thus, the results show that while vitamins A, E, C, and Se levels decreased, MDA levels and GSH-Px activities increased after administration of 3-(1H-pyrrol-2-yl)-1H-indazole to the rats. These findings might be related to the increased amount of free radicals caused by 3-(1H-pyrrol-2-yl)-1H-indazole injection.

Synthesis and Characterization of a New Methacrylate Polymer with Side Chain Benzofurane and Cyclobutane Ring: Thermal Properties and Antimicrobial Activity

The synthesis of a new methacrylate monomer (Benzofuran-2-yl)(3-mesityl-3-methylcyclobutyl)- O-methacrylketoxime is described. The monomer was polymerized in 1,4 dioxane solution at 65 °C using azobisisobutyronitrile as an initiator. The monomer and its polymers were characterized by infrared, and 1H-NMR spectroscopy. The glass transition temperature of the polymer was investigated by differential scanning calorimetry and the apparent thermal decomposition activation energies ( Ed) were calculated by the Ozawa method using a Shimadzu thermogravimetric analysis thermobalance. The Ed were values were determined to be 231 kJ mol-1. The antibacterial and antifungal effects of the momomer and its homopolymer were also investigated on various bacteria and fungi.

Synthesis and antimicrobial activity of some novel derivatives of benzofuran: Part 2. The synthesis and antimicrobial activity of some novel 1-(1-benzofuran-2-yl)-2-mesitylethanone derivatives

The reaction of salicylaldehyde with 1-chloro-3-mesitylacetone (2) and potassium carbonate was used to prepare 1-(1-benzofuran-2-yl)-2-mesitylethanone (4) for the starting reagent purposes. 1-(1-Benzofuran-2-yl)-2-mesitylethanoneoxime (5) was synthesized by the reaction of the compound (4) with hydroxylamine. New derivative of 1-(1-benzofuran-2-yl)-2-mesitylethanoneoxime (5) as 1-(1-benzofuran-2-yl)-2-mesitylethanonesemicarbazone (7) was obtained in very high yields. Alkyl substituted N-oxime ethers (8a-d) were obtained by the reaction compound 5 and various halogen contained compounds. The compounds 9a-d were synthesized by the reaction of the compound (5) and four different acyl chlorides. Some of the synthesized compounds were tested for antimicrobial activity against Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 25922 and Candida albicans ATCC 10231. Among the synthesized compounds (E)-1-(1-benzofuran-2-yl)-2-mesitylethanone-O-benzoyloxime (9b) was found the most active derivative against S. aureus ATCC 6538 and E. coli ATCC 25922. The other compounds exhibited moderate activity against the other test microorganisms.

Investigation of oxidative status of the 2-furan-2-yl-1H-benzimidazole in rats

We investigated the influence of 2-furan-2-yl-1H-benzimidazole regarding vitamins A, E, C, selenium (Se), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) levels on rats. 2-Furan-2-yl-1H-benzimidazole was given to rats by subcutaneous injection every other day for a total of 22 injections. At the end of the experiment, Se levels were determined by using a fluorimetric method. Serum levels of vitamins A, E, C, and malondialdehyde (MDA) were determined by high-performance liquid chromatography. Glutathione peroxidase (GSH-Px) levels of erythrocytes were spectrophotometrically determined. Our experimental results showed that vitamins A, E, C, and Se levels were found generally lower than the control groups, while serum MDA level and GSH-Px activity flexibly increased, which is dependent on injection days. The observed decreases in vitamins A, E, C, and Se levels in the blood might be causally related to the increased amount of free radicals that are generated with 2-furan-2-yl-1H-benzimidazole injection. However, further investigations are needed to clarify the significance of this observation in respect with the 2-furan-2-yl-1H-benzimidazole injection.