Sodium citrate (SC) is sensitive to violet light illumination (VLI) and acts as a weak reductant. Conversely, gold (III) chloride trihydrate (GC) often acts as an oxidant in a redox reaction. In this study, the influences of colored light on the production of gold nanoparticles (AuNPs) in a mixture of gold (III) ions and citrate via VLI and the antibacterial photodynamic inactivation (aPDI) of () are determined under alkaline conditions.
View Article and Find Full Text PDFGold nanoparticles (GNPs) are usually formed via a wet chemical method using gold (III) chloride trihydrate (GC), which is treated with stable reducing agents such as sodium citrate (SC). This study determines the effect of coloured light on the formation of GNPs by irradiation of SC after the addition of GC (SCGC) and the effect of the SCGC photolytic procedure on the suppression of WiDr colon cancer cells by forming reactive oxygen species. The absorbance of surface plasmon resonance peaks at 523 nm are 0.
View Article and Find Full Text PDFChem Commun (Camb)
December 2023
Photochemical reductive deamination of alpha-amino aryl alkyl ketones under photosensitizer-free conditions is presented. This protocol features high efficiency and selectivity. A plausible reaction pathway is proposed based on ultraviolet-visible absorption investigation, control experiments and deuterium-labelling studies.
View Article and Find Full Text PDFRiboflavin-5'-phosphate (FMN), an innocuous product of riboflavin (RF) phosphorylation, is vital for humans. FMN is sensitive to light illumination, as indicated by reactive oxygen species (ROS) formation. This investigation was undertaken to evaluate the influence of blue light illumination (BLI) and violet light illumination (VLI) upon FMN to develop a method to inhibit WiDr colon cancer cells by FMN photolysis.
View Article and Find Full Text PDFOxytetracycline (OTC), a tetracycline antibiotic, is a broad-spectrum antibacterial agent. In this investigation, liquid chromatography-mass spectrometry (LC-MS) is utilized to determine the effects of blue light (λ = 448 nm) illumination (BLIA) and violet light (λ = 403 nm) illumination (VLIA) on conformational changes in OTC at pH 7.8.
View Article and Find Full Text PDFRiboflavin-5'-phosphate (or flavin mononucleotide; FMN) is sensitive to visible light. Various compounds, including reactive oxygen species (ROS), can be generated from FMN photolysis upon irradiation with visible light. The ROS generated from FMN photolysis are harmful to microorganisms, including pathogenic bacteria such as Staphylococcus aureus (S.
View Article and Find Full Text PDFDoxycycline hyclate (DCH) and minocycline hydrochloride (MH) are tetracycline antibiotics and broad-spectrum antimicrobial agents. The changes in DCH and MH under blue light (λ = 462 nm) irradiation in alkaline conditions (BLIA) were investigated. Deactivation caused by superoxide anion radical (O) and deactivation from DCH and MH during photolysis on Staphylococcus aureus (S.
View Article and Find Full Text PDFTea is rich in catechins and aluminum. In this study, the process of catechin photolysis was applied as a model for examining the effects of aluminum chloride (AlCl) on the structural changes of catechin and the alteration of aluminum complexes under blue light irradiation (BLI) at pH 8 using liquid chromatography and mass spectrometry techniques. Additionally, the effects of anions on catechin upon the addition of AlCl and treatment with BLI were also studied.
View Article and Find Full Text PDFTetracycline (TC) is a broad-spectrum antibiotic compound. Wastewater with TC may have an adverse effect on ecosystems. Riboflavin-5'-phosphate (FMN or flavin mononucleotide) is a non-toxic product of the phosphorylation of vitamin B and is required for the proper functioning of the humans.
View Article and Find Full Text PDFCatechins belonging to polyhydroxylated polyphenols are the primary compounds found in green tea. They are associated with many physiological properties. Epicatechin (EC) is a non-gallate-type catechin with four phenolic hydroxyl groups attached.
View Article and Find Full Text PDFThe adaptability of bacterial resistance to antibiotics contributes to its high efficiency during evolution. Tetracycline (TC) is a broad-spectrum antimicrobial agent. Chromatographic analyses and mass spectrometry were used to study the effects of the light illumination of a 462 nm light-emitting diode (LED) on the conformational changes of TC in a phosphate buffer solution (PBS, pH 7.
View Article and Find Full Text PDFCatechin is a flavan-3-ol, a derivative of flavans, with four phenolic hydroxyl groups, which exhibits a wide range of physiological properties. Chromatographic analyses were employed to examine the effects of blue light irradiation on the changes of catechin hydrate in an alkaline condition. In particular, the detection of a superoxide anion radical (O₂•), a reactive oxygen species (ROS), and the inactivation of ()—including a carbapenem-resistant (CRAB)—was investigated during the photoreaction of catechin hydrate.
View Article and Find Full Text PDFCrystal violet (CV) is applied in daily use mainly as a commercial dye and antimicrobial agent. Waste water containing CV may affect aquatic ecosystems. Riboflavin, also known as vitamin B, is non-toxic and an essential vitamin required for the functions of the human body.
View Article and Find Full Text PDFThe light sensitive compound riboflavin-5'-phosphate (or flavin mononucleotide, FMN) generates reactive oxygen species (ROS) upon photo-irradiation. FMN is required by all flavoproteins because it is a cofactor of biological blue-light receptors. The photochemical effects of FMN after irradiation by blue or violet light on the inactivation of Staphylococcus aureus strains, including a methicillin-resistant strain (MRSA), were investigated in this study.
View Article and Find Full Text PDFJ Photochem Photobiol B
December 2016
Polyphenols are associated with a wide range of physiological properties. Catechin is a flavan-3-ol with five phenolic hydroxyl groups. After blue light illumination, the transparent solution of catechin became yellowish.
View Article and Find Full Text PDFS-doped Na2Ti6O13@TiO2 (S-TTO) core-shell nanorods, with exposed anatase TiO2 {101} facets, were synthesized by a facile calcination method. It was found that the addition of thiourea as the sulfur precursor was beneficial for the formation of anatase TiO2 with a better crystallinity and the doped sulfur atoms favorably stabilized the anatase structure. The substitution of Ti(4+) by S(6+) in the lattice of S-TTO gave rise to the visible light response and increased the amount of active groups typically as a hydroxyl radical adsorbed onto the catalyst surface.
View Article and Find Full Text PDFDetermination of the superoxide dismutase activity is an important issue in the fields of biochemistry and the medical sciences. In the riboflavin/nitro blue tetrazolium (B2/NBT) method, the light sources used for generating superoxide anion radicals from light-excited riboflavin are normally fluorescent lamps. However, the conditions of B2/NBT experiments vary.
View Article and Find Full Text PDFThe micronutrients in many cellular processes, riboflavin, flavin mononucleotide (FMN), and flavin adenine dinucleotide (FAD) are photo-sensitive to UV and visible light for generating reactive oxygen species (ROS). Produced from phosphorylation of riboflavin, FMN is more water-soluble and rapidly transformed into free riboflavin after ingestion. This study investigated the application of visible blue light with FMN to development of an effective antimicrobial treatment.
View Article and Find Full Text PDFThe Folin-Ciocalteu method is widely applied for the determination of the total phenolic contents in natural products. This method is significantly affected by the addition of sodium carbonate. The currently applied Folin-Ciocalteu methods may have been modified without any validation in the quantitative standards and the order of processes.
View Article and Find Full Text PDFAn effective approach has been used to synthesize N-doped HTiNbO5 (denoted as N-HTiNbO5) with a better intercalation property. The synthesis of polyaniline (PANI) with N-HTiNbO5 to form PANI-N-HTiNbO5 lamellar nanocomposites by in situ polymerization using the aniline (ANI) intercalation compound ANI/N-HTiNbO5 as the intermediate has been investigated. The resulting PANI-N-HTiNbO5 nanocomposite showed a better crystallinity with a monolayer of PANI within the interlayers of N-HTiNbO5, because nitrogen doping can affect the surface charge distribution of [TiNbO5](-) layers.
View Article and Find Full Text PDFJ Photochem Photobiol B
February 2013
The micronutrients in many cellular processes, riboflavin (vitamin B(2)), FMN, and FAD are photo-sensitive to UV and visible light to generate reactive oxygen species (ROS). The riboflavin photochemical treatment with UV light has been applied for the inactivation of microorganisms to serve as an effective and safe technology. Ultra-violet or high-intensity radiation is, however, considered as a highly risky practice.
View Article and Find Full Text PDF