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In this study, the phytochemical composition, in vitro antioxidant, and anti-inflammatory effects of the aqueous and 60% ethanolic (EtOH) extracts of Santolina rosmarinifolia leaf, flower, and root were examined. The antioxidant activity of S. rosmarinifolia extracts was determined by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays. The total phenolic content (TPC) of the extracts was measured by the Folin–Ciocalteu assay. The anti-inflammatory effect of the extracts was monitored by the Griess assay. The chemical composition of S. rosmarinifolia extracts was analysed using the LC-MS technique. According to our findings, 60% EtOH leaf extracts showed the highest Trolox equivalent antioxidant capacity (TEAC) values in both ABTS (8.39 ± 0.43 µM) and DPPH (6.71 ± 0.03 µM) antioxidant activity assays. The TPC values of the samples were in good correspondence with the antioxidant activity measurements and showed the highest gallic acid equivalent value (130.17 ± 0.01 µg/mL) in 60% EtOH leaf extracts. In addition, the 60% EtOH extracts of the leaves were revealed to possess the highest anti-inflammatory effect. The LC-MS analysis of S. rosmarinifolia extracts proved the presence of ascorbic acid, catalpol, chrysin, epigallocatechin, geraniol, isoquercitrin, and theanine, among others, for the first time. However, additional studies are needed to investigate the direct relationship between the chemical composition and physiological effects of the herb. The 60% EtOH extracts of S. rosmarinifolia leaves are potential new sources of natural antioxidants and anti-inflammatory molecules in the production of novel nutraceutical products. [ABSTRACT FROM AUTHOR]

A facile and efficient method for the regioselective [3 + 2] cycloaddition of 4-azidofuroxans to 1-dimethylamino-2-nitroethylene under p-TSA catalysis affording (4-nitro-1,2,3-triazolyl)furoxans was developed. This transformation is believed to proceed via eliminative azide–olefin cycloaddition resulting in its complete regioselectivity. The developed protocol has a broad substrate scope and enables a straightforward assembly of the 4-nitro-1,2,3-triazole motif. Moreover, synthesized (4-nitro-1,2,3-triazolyl)furoxans were found to be capable of NO release in a broad range of concentrations, thus providing a novel platform for future drug design and related biomedical applications of heterocyclic NO donors. [ABSTRACT FROM AUTHOR]

Chronic inflammation plays an important role in the development of neurodegenerative diseases, such as Parkinson's disease (PD). In the present study, we synthesized 25 novel xanthine derivatives with variable substituents at the N1-, N3- and C8-position as adenosine receptor antagonists with potential anti-inflammatory activity. The compounds were investigated in radioligand binding studies at all four human adenosine receptor subtypes, A1, A2A, A2B and A3. Compounds showing nanomolar A2A and dual A1/A2A affinities were obtained. Three compounds, 19, 22 and 24, were selected for further studies. Docking and molecular dynamics simulation studies indicated binding poses and interactions within the orthosteric site of adenosine A1 and A2A receptors. In vitro studies confirmed the high metabolic stability of the compounds, and the absence of toxicity at concentrations of up to 12.5 µM in various cell lines (SH-SY5Y, HepG2 and BV2). Compounds 19 and 22 showed anti-inflammatory activity in vitro. In vivo studies in mice investigating carrageenan- and formalin-induced inflammation identified compound 24 as the most potent anti-inflammatory derivative. Future studies are warranted to further optimize the compounds and to explore their therapeutic potential in neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Nitrite has been determined using a simple and sensitive spectrophotometric method. The suggested procedure is based on the diazotization reaction of p-bromoaniline in the presence of nitrite ion in a hydrochloric acid media, which produces diazonium salt. This salt is then combined with paracetamol in an ammonium hydroxide medium to produce an orange azo color with a maximum wavelength (λ max.) of 460 nm, molar absorptivity (ε) is 3.8432 x 103 L. mol-l.cm-1, and Beer’s law was established between 0.3-12.0 µg. mL-1. It displays LOD, LOQ, and R2 values of 0.2 µg. mL-1, 0.3 µg. mL-1, and 0.9994 respectively. The dye can be extracted into chloroform. The yellow chloroform extract displays a maximum wavelength (λ max.) of 410 nm, molar absorptivity (ε) is 9.93 x103 L. mol-l.cm-1, and Beer’s law was observed between 0.1-5.0 µg. mL-1. The LOD, LOQ, and R2 values for the suggested extraction procedure were 0.05 µg. mL-1, 0.1 µg. mL-1, and 0.9996, respectively. The suggested method was successfully applied on samples of a human saliva.

A photoactivable NO releasing complex [Ru(L1-2)(PPh 3)(NO)Cl 2 ](PF 6) (1a) have been synthesized by complex [RuL1-2(PPh 3) 2 Cl 2 ](1). Newly designed bidentate ligands, i.e., 4-methoxy- N ′-phenyl- N '-(pyridin-2-ylmethyl)benzohydrazide(L 1 ) and 4-nitro- N ′-phenyl- N '-(pyridin-2-ylmethyl)benzohydrazide (L 2 ) were utilized to synthesize complex (1). Complex (1) was characterized by ESI-MS, and the solid structure of the complex [ 1a ](PF 6) was acquired by X-ray crystallography. Different spectroscopic techniques were employed for the identification of ligands (L 1 and L 2 ) and complexes (1 and [ 1a ](PF 6)). Calculations employing DFT and TD-DFT were made better to understand the electronic properties of the complex [ 1a ](PF 6). The photo liberation experiments were screened in the presence of visible light lamp. Griess assay experiment was used to quantify the photo released amount to NO. The photo liberated NO was successfully transferred to reduced myoglobin (Mb). The complex [ 1a ](PF 6) at 50 μg/mL concentration was used for wound healing and antimicrobial activity on B16F1 mouse skin cells and Escherichia coli bacteria, respectively. In results, we observed a considerable wound healing activity of [ 1a ](PF 6) complex after 36 h of incubation in the light-treated cells compared to the control medium, and also it shows more than 99% inhibition of bacterial cells after 1.5 h of treatment in the presence of light. These study suggested that this complex 1a ](PF 6) could be utilized for topical delivery of NO for combating several dermatological infections. [Display omitted] • Synthesis of visible light activatable RuNO complex, release NO under illumination. • Light-triggered NO has been transported to reduced myoglobin. • The visible-light triggered NO was assessed by the Griess experiment. • Light-triggered NO delivery reveals potential in wound healing and antibacterial treatments. • This type of NO complex can deliver NO to a site specific targets on demand. [ABSTRACT FROM AUTHOR]

• Development and validation of visible light-activatable nitrosyl complexes of ruthenium under the illumination of low intensity light. • Reduced myoglobin has been delivered using light-triggered NO. • The Griess experiment was used to examine the visible-light triggered NO. • Antibacterial activity examined under the exposure of visible light. • This kind of NO complexes may immediately release NO to targets located at a certain spot. In this article, a chloro-bridged dinuclear ruthenium complex Ru-(a) has been synthesized, which was employed for the synthesis of a photolabile NO liberating complex Ru-(b). A newly synthesized tridentate ligand 2-methyl-6-((2-phenyl-2-(pyridin-2-yl)hydrazineylidene)methyl)pyridine with three N-atoms as donating site was used to synthesize the complex Ru-(a). The molecular structure of Ru-(a) was investigated by single-crystal X-ray crystallography and, in solution was characterized by or ESI mass spectrometry. Several spectroscopic techniques were used for the characterization of the ligand as well as complexes. To understand the electronic structure of Ru-(a) and Ru-(b) , DFT computations were utilized. By the utilization of visible light, photo-liberation experiments were examined. The amount of NO released during the photodissociation experiment was measured using the Griess reagent assay technique. The photodissociated NO was fruitfully transported to reduced myoglobin (Mb). The antibacterial activity against Escherichia coli was carried out with 31.2 μg/mL concentration of Ru-(b). In the final results, we detected considerable antibacterial activity against E. coli and showed >99 % inhibition of the bacterial cells after 120 min of the experiment on exposure to visible light. These investigations proposed that Ru-(b) could be employed to treat several topical deliveries of NO for treating various topical and bacterial infections. [Display omitted] [ABSTRACT FROM AUTHOR]

A facile and efficient method for the regioselective [3 + 2] cycloaddition of 4-azidofuroxans to 1-dimethylamino-2-nitroethylene under p-TSA catalysis affording (4-nitro-1,2,3-triazolyl)furoxans was developed. This transformation is believed to proceed via eliminative azide–olefin cycloaddition resulting in its complete regioselectivity. The developed protocol has a broad substrate scope and enables a straightforward assembly of the 4-nitro-1,2,3-triazole motif. Moreover, synthesized (4-nitro-1,2,3-triazolyl)furoxans were found to be capable of NO release in a broad range of concentrations, thus providing a novel platform for future drug design and related biomedical applications of heterocyclic NO donors.

Chronic inflammation plays an important role in the development of neurodegenerative diseases, such as Parkinson’s disease (PD). In the present study, we synthesized 25 novel xanthine derivatives with variable substituents at the N1-, N3- and C8-position as adenosine receptor antagonists with potential anti-inflammatory activity. The compounds were investigated in radioligand binding studies at all four human adenosine receptor subtypes, A1, A2A, A2B and A3. Compounds showing nanomolar A2A and dual A1/A2A affinities were obtained. Three compounds, 19, 22 and 24, were selected for further studies. Docking and molecular dynamics simulation studies indicated binding poses and interactions within the orthosteric site of adenosine A1 and A2A receptors. In vitro studies confirmed the high metabolic stability of the compounds, and the absence of toxicity at concentrations of up to 12.5 µM in various cell lines (SH-SY5Y, HepG2 and BV2). Compounds 19 and 22 showed anti-inflammatory activity in vitro. In vivo studies in mice investigating carrageenan- and formalin-induced inflammation identified compound 24 as the most potent anti-inflammatory derivative. Future studies are warranted to further optimize the compounds and to explore their therapeutic potential in neurodegenerative diseases.

Three EPR silent dinitrosyl cobalt complexes (DNCCs) containing a {Co(NO) 2 }10 unit were synthesized and characterized by cyclic voltammograms, NMR and X-ray diffraction, etc. The DNCCs have demonstrated significantly enhanced NO release efficacy in DMEM/F-12 medium, enhanced NO cellular uptake by human umbilical vein endothelial cells as well as low toxicity than marketed sodium nitroprusside. [Display omitted] • Dinitrosyl cobalt complexes demonstrate more efficient and sustained NO release than sodium nitroprusside. • Dinitrosyl cobalt complexes exhibit fast and efficient NO cellular uptake by human umbilical vein endothelial cells. • Dinitrosyl cobalt complexes demonstrate low cytotoxicity to human umbilical vein endothelial cells. Three dinitrosyl cobalt complexes (DNCCs) [(Dppe)Co(NO) 2 ]Cl , [(Dppp)Co(NO) 2 ]Cl and [(TMEDA)Co(NO) 2 ]BPh 4 were synthesized using CoCl 2 ·6H 2 O as a starting material and were isolated via fast column chromatography with final yields ranging from 53% to 67%. These EPR silent DNCCs each showed only one pair of redox events ({Co(NO) 2 }10/11) in the cyclic voltammograms. In comparison with sodium nitroprusside (SNP), the DNCCs' NO release amount and duration significantly enhanced, and were related closely to their hydrolytic stability. Additionally, DNCCs have demonstrated significantly higher NO cellular uptake rates in the first 5 h than SNP by human umbilical vein endothelial cells (HUVEC), to which the DNCCs also showed low cytotoxicity. Based on the fact that DNCCs could hydrolyze yielding ligands as the remaining products and the possible formation of [(Dppp)Co(NO) 2 ] and [(Dppp)Co(PPh 3)(NO)] in the reduction of [(Dppp)Co(NO) 2 ]Cl , a plausible NO release mechanism via a one electron reduction process was proposed. [ABSTRACT FROM AUTHOR]