Search Results (34)

Current research on the synthesis of isonicotinic acid (INA) has focused on the development of catalysts by mixing transition metal oxides such as vanadium, titanium and zirconium in the desired molar ratio. These materials have good catalytic activity (CA) but have drawbacks, including low resistance to deactivation and limited ability to control reaction selectivity. In the present study, two- and three-component catalysts containing vanadium were successfully synthesized and their compositions and properties were studied. The experimental results showed that the efficiency of V-Ti-Mn-O catalyst was superior to V-Ti-O. Selectivity analysis showed that V-Ti-Mn-O was the most efficient catalyst, reaching a maximum value of 67.17% at 320 °C. Scanning electron microscope (SEM), Raman spectroscopy and X-ray diffraction (XRD) were used to characterize the catalysts. The corresponding experimental results showed that the superior performance of the V-Ti-Mn-O catalyst was attributed to both the smaller size of the catalyst particles and their more uniform distribution. In the oxidation of 4-methylpyridine (4-MP), the V-Ti-O catalyst showed lower CA and stability compared to the V-Ti-Mn-O catalyst, which can be attributed to its limited CA and potential deactivation at higher temperatures, probably due to excessive oxidation. Full article

Pyracantha fortuneana, an underutilized wild plant, has been found to have a high nutritional value. This study used simulated digestion and fecal fermentation models to investigate the digestive properties of the purified acidic pectin polysaccharide of Pyracantha fortuneana and its impact on the gut microbiota and metabolites. Pyracantha fortuneana polysaccharide (PFP) is mainly composed of rhamnose (Rha), galacturonic acid (GalA), glucose (Glc), galactose (Gal), and arabinose (Ara), with a molecular weight (Mw) of 851.25 kDa. Following simulated digestion, the Mw of PFP remained consistent. The reduced sugar content showed minimal change, suggesting that PFP exhibits resistance to gastrointestinal digestion and can effectively reach the colon. Following fecal fermentation, the molecular weight, monosaccharide, and carbohydrate contents of PFP decreased, while the short-chain fatty acid content increased. This suggests that PFP is susceptible to degradation by microorganisms and can be metabolized into acetic acid and n-butyric acid, contributing to the regulation of intestinal health. Meanwhile, PFP promotes the reproduction of beneficial bacteria such as Bacteroides, Dialister, and Dysgonomonas, inhibits the growth of harmful bacteria like Proteus, and generates metabolites such as thiamine, leonuriside A, oxoadipic acid, S-hydroxymethylglutathione, and isonicotinic acid, which exert beneficial effects on human health. These results indicate that PFP has great potential in regulating the gut microbiota and generating beneficial metabolites to promote intestinal functional health and can be used as a prebiotic to prevent diseases by improving intestinal health. Full article

Background/Objectives: Cancer remains one of the major challenges of our century. Organometallic ruthenium complexes are gaining recognition as a highly promising group of compounds in the development of cancer treatments. Methods: Building on the auspicious results obtained for [Ru(η⁵-C₅H₅)(PPh₃)(bipy)][CF₃SO₃] (TM34), our focus has shifted to examining the effects of incorporating bioactive ligands into the TM34 framework, particularly within the cyclopentadienyl ring. Results: In this study, we report the synthesis and characterization of two new ruthenium(II) complexes with the general formula [Ru(η⁵-C₅H₄CCH₃=R)(PPh₃)(bipy)][CF₃SO₃], where R represents a nicotinic acid derivative (NNHCO(py-3-yl)) (1) or an isoniazid derivative (NNHCO(py-4-yl)) (2). The complexes were fully characterized using a combination of spectroscopic techniques and computational analysis, revealing the presence of E/Z-hydrazone isomerism. Stability studies confirmed the robustness of both complexes in biological media, with compound 1 maintaining good stability in buffer solutions mimicking physiological (pH 7.4) and tumor-like (pH 6.8) environments. The cytotoxicity of the complexes was evaluated in vitro in several human cancer cell lines, namely melanoma (A375), alveolar adenocarcinoma (A549), epidermoid carcinoma (A431), and breast cancer (MDA-MB 231). Conclusions: Both compounds exhibited moderate to high cytotoxic activity, with complex 1 showing a greater propensity to induce cell death, particularly in the A431 and MDA-MB 231 cell lines. Full article

The present article describes the synthesis of an isonicotinate-derived meso-arylporphyrin, that has been fully characterized by spectroscopic methods (including fluorescence spectroscopy), as well as elemental analysis and HR-MS. The structure of an n-hexane monosolvate has been determined by single-crystal X-ray diffraction analysis. The radical scavenging activity of this new porphyrin against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical has been measured. Its antifungal activity against three yeast strains (C. albicans ATCC 90028, C. glabrata ATCC 64677, and C. tropicalis ATCC 64677) has been tested using the disk diffusion and microdilution methods. Whereas the measured antioxidant activity was low, the porphyrin showed moderate but encouraging antifungal activity. Finally, a study of its effect on the germination of lentil seeds revealed interesting allelopathic properties. Full article

Abstract: Interest in glutinous rice consumption has been expanding in East Asia. However, the extent of metabolite variation between common and glutinous rice has not been fully explored to identify metabolic targets for rice quality improvement. Thus, the objective of this study was to provide insights into the variation of metabolites and nutraceuticals between common and glutinous rice. Two black rice (common rice, BL-N, and glutinous rice, BL-G) and two white rice (common rice, WH-N, and glutinous rice, WH-G) types were analysed via LC-MS-based widely targeted metabolic profiling. We identified 441 and 343 types, including 160 key overlapping differentially accumulated metabolites between BL-N_vs_BL-G and WH-N_vs_WH-G, respectively. Glutinous rice showed a higher relative content of most categories of metabolites, except for quinones (in BL-N) and tannins (in WH-N). Seven vitamins, including B6, B3, B5, B13, isonicotinic acid, N-(beta-D-glucosyl)nicotinate, and 4-pyridoxic acid-O-glucoside, were significantly up-regulated in BL-G compared to BL-N. The biosynthesis of cofactors, zeatin biosynthesis, citrate cycle, amino acid metabolism, alpha-linolenic acid metabolism, and glyoxylate and dicarboxylate metabolism was the most differentially regulated pathway. Key differential metabolites in citrate cycle include citrate, isocitrate, fumarate, malate, succinate, and 2-oxoglutarate; in amino acid metabolism (L-serine, L-cysteine, L-lysine, L-glutamine, L-methionine, and L-tryptophan); and in glycolysis (UDP-glucose, D-glucose-1P, D-glucose-6P, and D-fructose-6P). The data resources in this study may contribute to a better understanding of the function and nutritional value of glutinous rice. Full article

Pigmented rice grains are important resources for health and nutritional perspectives. Thus, a thorough dissection of the variation of nutrients and bioactive metabolites in different colored rice is of global interest. This study applied LC–MS-based widely targeted metabolite profiling and unraveled the variability of metabolites and nutraceuticals in long grain/non-glutinous black (BR), red (RR), green (GR), and white rice (WR) grains. We identified and classified 1292 metabolites, including five flavonoid compounds specific to BR. The metabolite profiles of the four rice grains showed significant variation, with 275–543 differentially accumulated metabolites identified. Flavonoid (flavone, flavonol, and anthocyanin) and cofactor biosynthesis were the most differentially regulated pathways among the four rice types. Most bioactive flavonoids, anthocyanidins (glycosylated cyanidins and peonidins), phenolic acids, and lignans had the highest relative content in BR, followed by RR. Most alkaloids, amino acids and derivatives, lipids, and vitamins (B6, B3, B1, nicotinamide, and isonicotinic acid) had higher relative contents in GR than others. Procyanidins (B1, B2, and B3) had the highest relative content in RR. In addition, we identified 25 potential discriminatory biomarkers, including fagomine, which could be used to authenticate GR. Our results show that BR and RR are important materials for medicinal use, while GR is an excellent source of nutrients (amino acids and vitamins) and bioactive alkaloids. Moreover, they provide data resources for the science-based use of different colored rice varieties in diverse industries. Full article

The hydrazones 3a–c, were synthesized from the reaction of indole-3-carbaldehyde and nicotinic acid hydrazide, isonicotinic acid hydrazide, and benzoic acid hydrazide, respectively. Their structures were confirmed using FTIR, ¹HNMR, and ¹³CNMR spectroscopic techniques. Exclusively, hydrazones 3b and 3c were confirmed using single crystal X-ray crystallography to exist in the Eanti form. With the aid of DFT calculations, the most stable configuration of the hydrazones 3a–c in gas phase and in nonpolar solvents (CCl₄ and cyclohexane) is the ESyn form. Interestingly, the DFT calculations indicated the extrastability of the EAnti in polar aprotic (DMSO) and polar protic (ethanol) solvents. Hirshfeld topology analysis revealed the importance of the N…H, O…H, H…C, and π…π intermolecular interactions in the molecular packing of the studied systems. Distribution of the atomic charges for the hydrazones 3a–c was presented. The hydrazones 3a–c showed a polar character where 3b has the highest polarity of 5.7234 Debye compared to the 3a (4.0533 Debye) and 3c (5.3099 Debye). Regarding the anti-toxoplasma activity, all the detected results verified that 3c had a powerful activity against chronic toxoplasma infection. Compound 3c showed a considerable significant reduction percent of cyst burden in brain homogenates of toxoplasma infected mice representing 49%. Full article

Using oleanolic acid as a starting compound, a series of new oleanane-type triterpenic derivatives were synthesized via O-acylation (with nicotinic, isonicotinic, and methoxycinnamic acid acyl chlorides), N-amidation (with cyclic- or polyamines), the Mannich reaction (with secondary cyclic amines), and Claisen–Schmidt condensation (with aromatic aldehydes), and their potencies as treatments for immunometabolic disorders were investigated. The compounds were evaluated against α-glucosidase and PTP1B enzymes and LPS-stimulated murine macrophages. It was found that the target compounds are highly effective α-glucosidase inhibitors but lack activity against PTP1B. A leading compound, N-methylpiperazine methylated 2,3-indolo-oleanolic propargyl amide 15, is also a micromolar inhibitor of NO synthesis in LPS-stimulated macrophages and suppresses oxidative bursts in neutrophils with similar efficiency. These results, in addition to its ability to stimulate glucose uptake in rat fibroblasts and improve maltose tolerance in rats, allow us to consider compound 15 a promising prototype drug for the treatment of immunometabolic defects in type 2 diabetes. Full article

Bergenin (BER), a natural component of polyphenols, has a variety of pharmacological activities, especially in improving drug metabolism, reducing cholestasis, anti-oxidative stress and inhibiting inflammatory responses. The aim of this study was to investigate the effects of BER on liver injury induced by isonicotinic acid hydrazide (INH) and rifampicin (RIF) in mice. The mice model of liver injury was established with INH (100 mg/kg)+RIF (100 mg/kg), and then different doses of BER were used to intervene. The pathological morphology and biochemical indicators of mice were detected. Meanwhile, RNA sequencing was performed to screen the differentially expressed genes and signaling pathways. Finally, critical differentially expressed genes were verified by qRT-PCR and Western blot. RNA sequencing results showed that 707 genes were significantly changed in the INH+RIF group compared with the Control group, and 496 genes were significantly changed after the BER intervention. These differentially expressed genes were mainly enriched in the drug metabolism, bile acid metabolism, Nrf2 pathway and TLR4 pathway. The validation results of qRT-PCR and Western blot were consistent with the RNA sequencing. Therefore, BER alleviated INH+RIF-induced liver injury in mice. The mechanism of BER improving INH+RIF-induced liver injury was related to regulating drug metabolism enzymes, bile acid metabolism, Nrf2 pathway and TLR4 pathway. Full article

The isolation and structural characterization of a unique Cu(II) isonicotinate (ina) material with 4-acetylpyridine (4-acpy) is provided. The formation of [Cu(ina)₂(4-acpy)]_n (1) is triggered by the Cu(II) aerobic oxidation of 4-acpy using O₂. This gradual formation of ina led to its restrained incorporation and hindered the full displacement of 4-acpy. As a result, 1 is the first example of a 2D layer assembled by an ina ligand capped by a monodentate pyridine ligand. The Cu(II)-mediated aerobic oxidation with O₂ was previously demonstrated for aryl methyl ketones, but we extend the applicability of this methodology to heteroaromatic rings, which has not been tested so far. The formation of ina has been identified by ¹H NMR, thus demonstrating the feasible but strained formation of ina from 4-acpy in the mild conditions from which 1 was obtained. Full article

Solubility and crystallization studies of a monocarboxylic derivative of pyridine, picolinic acid (2-pyridinecarboxylic acid), were undertaken as a need for new data in the literature was identified. Moreover, comparative studies of structurally related small molecules, such as these pyridinecarboxylic acid isomers (picolinic acid (PA), nicotinic acid (NA, also known as Niacin or vitamin B₃), and isonicotinic acid (IA)), can contribute to a larger goal of identifying optimal crystallization conditions. Indeed, vitamin B₃ has been thoroughly explored in literature, whilst IA and, particularly, PA have received less attention. Hence, results on both the solubility (obtained through the gravimetric method) and solid-state structure (investigated by means of PXRD) of PA, at different temperatures, in three polar solvents: water, ethanol (both protic solvents) and acetonitrile (aprotic solvent) are presented in this work. These results indicate that PA is very soluble in water (for T ≈ 293 K, C_PA ≈ 862.5 g·kg⁻¹), way less soluble in ethanol (C_PA ≈ 57.1 g·kg⁻¹), and even less in acetonitrile (C_PA ≈ 17.0 g·kg⁻¹). The crystallization outcome was analyzed in comparison with its family of compounds data, revealing that two polymorphic forms were identifiable for PA, and that no hydrates or solvates were found. Full article

In this work, a copper iodine module bearing a coordination polymer (CP) with a formula of [(Cu₂I₂)₂Ce₂(INA)₆(DMF)₃]·DMF (1, HINA = isonicotinic acid, DMF = N,N’-dimethyl formamide) is presented. The title compound features a three dimensional (3D) structure, in which the {Cu₂I₂} cluster and {Cu₂I₂}_n chain modules are coordinated by N atoms from a pyridine ring in INA⁻ ligands, while the Ce³⁺ ions are bridged by the carboxylic groups of INA⁻ ligands. More importantly, compound 1 exhibits an uncommon red fluorescence (FL) with a single emission band maximized at 650 nm belonging to near infrared (NIR) luminescence. The temperature dependent FL measurement was applied to investigate the FL mechanism. Remarkably, 1 could be used as a FL sensor to cysteine and the nitro-bearing explosive molecule of trinitropheno (TNP) with high sensitivity, demonstrating its potential FL sensing applications for biothiol and explosive molecules. Full article

The effect of isonicotinic acid (INA) in a chitosan (CS)/polyvinyl alcohol (PVA) blend on ripening-dependent changes of preserved green tomatoes (Solanum lycopersicum L.) was examined at room temperature. The results showed that CS/PVA/INA 0.5 mM and CS/PVA/INA 1.0 mM formulations retarded firmness loss and delayed the pigmentation parameters i.e., lycopene (LYP), total carotenes (TCs), and titratable acidity (TA). The CS/PVA/INA 0.5 mM and CS/PVA/INA 1.0 mM formulations were able to delay the increase in malondialdehyde (MDA) and total polyphenol (TP) contents. Furthermore, the peroxidase (POD), polyphenoloxidase (PPO), and phenylalanine ammonia-lyase (PAL) activities of tomatoes coated with CS/PVA/INA 0.5 mM and CS/PVA/INA 1.0 mM formulations were lower than those in other treatments. Meanwhile, the CS/PVA blend had the highest TP content, as well as the highest PPO and PAL activities, at the late stage of maturation. The UV analysis showed that the CS/PVA/INA blend film is a promising UV-protective food packaging material. The pure CS, PVA, and INA formulations, as well as the CS/PVA, CS/PVA/INA 0.5 mM, and CS/PVA/INA 1.0 mM formulations, were characterized by infrared (FTIR). The three polymer formulations showed strong antifungal activity against Alternaria alternata and Botrytis cinerea. Full article

Isoniazid and its metabolites are potentially associated with hepatotoxicity and treatment outcomes in patients who receive antituberculosis (TB) therapy. To further understand the pharmacokinetic profiles of these molecules, a method based on LC-MS/MS was developed to determine the concentration of these compounds in human plasma. Isoniazid, acetylisoniazid, and isonicotinic acid were directly analyzed, whereas hydrazine and acetylhydrazine were determined after derivatization using p-tolualdehyde. Chromatographic separation was conducted on reversed-phase C18 columns with gradient elution, and detection was carried out in multiple reaction monitoring mode. The calibration curves were linear with correlation coefficients (r) greater than 0.9947 for all analytes. The intra- and inter-day precision was less than 13.43%, and the accuracy ranged between 91.63 and 114.00%. The recovery and matrix effect of the analytes were also consistent (coefficient of variation was less than 9.36%). The developed method successfully quantified isoniazid and its metabolites in TB patients. The method has broad applications in clinical research, including isoniazid one-point-based therapeutic drug monitoring, genotype–phenotype association studies of isoniazid metabolic profile and isoniazid-induced hepatotoxicity, and the initial dose prediction of isoniazid using population pharmacokinetic modeling. Full article

A series of co-crystals of ascorbic acid were prepared with equimolar amounts of co-crystal formers (CCFs), including isonicotinic acid, nicotinic acid, 3,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid and m-hydroxybenzoic acid, by slow solvent evaporation and solvent-assisted grinding. The co-crystals were characterized by single-crystal X-ray diffraction spectroscopy, powder X-ray diffraction, IR spectroscopy, differential scanning calorimetry and thermogravimetric analysis. Molecular dynamics (MD) simulations further validated the interaction energy and the possible intermolecular hydrogen bonds among VC and CCFs. The co-crystals showed improved stability when exposed to different wavelengths of light, pH and temperatures compared to the free analogue, especially at higher pH (~9) and lower temperature (~4 °C). Full article