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Journal of Hazardous Materials Jun 2023Increasing drug residues in aquatic environments have been caused by the abuse of antivirals since the global spread of the COVID-19 epidemic, whereas research on the...
Increasing drug residues in aquatic environments have been caused by the abuse of antivirals since the global spread of the COVID-19 epidemic, whereas research on the photolytic mechanism, pathways and toxicity of these drugs is limited. The concentration of COVID-19 antivirals ribavirin in rivers has been reported to increase after the epidemic. Its photolytic behavior and environmental risk in actual waters such as wastewater treatment plant (WWTP) effluent, river water and lake water were first investigated in this study. Direct photolysis of ribavirin in these media was limited, but indirect photolysis was promoted in WWTP effluent and lake water by dissolved organic matter and NO. Identification of photolytic intermediates suggested that ribavirin was photolyzed mainly via C-N bond cleavage, splitting of the furan ring and oxidation of the hydroxyl group. Notably, the acute toxicity was increased after ribavirin photolysis owing to the higher toxicity of most of the products. Additionally, the overall toxicity was greater when ARB photolysis in WWTP effluent and lake water. These findings emphasize the necessity to concern about the toxicity of ribavirin transformation in natural waters, as well as to limit its usage and discharge.
Topics: Humans; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Antiviral Agents; COVID-19; Photolysis; Ribavirin; Water; Water Pollutants, Chemical
PubMed: 37002997
DOI: 10.1016/j.jhazmat.2023.131320 -
Molecules (Basel, Switzerland) May 2022The development of multifunctional nanomaterials has received growing research interest, thanks to its ability to combine multiple properties for severing highly...
The development of multifunctional nanomaterials has received growing research interest, thanks to its ability to combine multiple properties for severing highly demanding purposes. In this work, holmium oxide nanoparticles are synthesized and characterized by various tools including XRD, XPS, and TEM. These nanoparticles are found to emit near-infrared fluorescence (800-1100 nm) under a 785 nm excitation source. Imaging of the animal tissues was demonstrated, and the maximum imaging depth was found to be 2.2 cm. The synthesized nanoparticles also show the capability of facilitating dye (fluorescein sodium salt and rhodamine 6G) degradation under white light irradiation. The synthesized holmium oxide nanoparticles are envisioned to be useful for near-infrared tissue imaging and dye-degradation.
Topics: Animals; Holmium; Light; Nanoparticles; Oxides; Photolysis
PubMed: 35684461
DOI: 10.3390/molecules27113522 -
Journal of the American Society For... Feb 2018Mass spectrometry-based methods have made significant progress in characterizing post-translational modifications in peptides and proteins; however, certain aspects...
Mass spectrometry-based methods have made significant progress in characterizing post-translational modifications in peptides and proteins; however, certain aspects regarding fragmentation methods must still be improved. A good technique is expected to provide excellent sequence information, locate PTM sites, and retain the labile PTM groups. To address these issues, we investigate 10.6 μm IRMPD, 213 nm UVPD, and combined UV and IR photodissociation, known as HiLoPD (high-low photodissociation), for phospho-, sulfo-, and glyco-peptide cations. IRMPD shows excellent backbone fragmentation and produces equal numbers of N- and C-terminal ions. The results reveal that 213 nm UVPD and HiLoPD methods can provide diverse backbone fragmentation producing a/x, b/y, and c/z ions with excellent sequence coverage, locate PTM sites, and offer reasonable retention efficiency for phospho- and glyco-peptides. Excellent sequence coverage is achieved for sulfo-peptides and the position of the SO group can be pinpointed; however, widespread SO losses are detected irrespective of the methods used herein. Based on the overall performance achieved, we believe that 213 nm UVPD and HiLoPD can serve as alternative options to collision activation and electron transfer dissociations for phospho- and glyco-proteomics. Graphical Abstract ᅟ.
Topics: Amino Acid Sequence; Glycopeptides; Infrared Rays; Mass Spectrometry; Peptides; Phosphopeptides; Photolysis; Protein Processing, Post-Translational; Sulfur; Ultraviolet Rays
PubMed: 28980177
DOI: 10.1007/s13361-017-1794-9 -
The Journal of Organic Chemistry Mar 2020Despite its importance in the design of photocaged molecules, less attention is focused on linker chemistry than the cage itself. Here, we describe unique uncaging...
Despite its importance in the design of photocaged molecules, less attention is focused on linker chemistry than the cage itself. Here, we describe unique uncaging properties displayed by two coumarin-caged thymidine compounds, each conjugated with () or without () an extended, self-immolative spacer. Photolysis of using long-wavelength UVA (365 nm) or visible (420, 455 nm) light led to the release of free thymidine along with the competitive generation of a thymidine-bearing recombination product. The occurrence of this undesired side reaction, which is previously unreported, was not present with the photolysis of , which released thymidine exclusively with higher quantum efficiency. We propose that the spatial separation between the cage and the substrate molecule conferred by the extended linker can play a critical role in circumventing this unproductive reaction. This report reinforces the importance of linker selection in the design of coumarin-caged oligonucleosides and other conjugates.
Topics: Coumarins; Photolysis; Thymidine
PubMed: 32020803
DOI: 10.1021/acs.joc.9b02617 -
Efficient Photocatalytic Degradation of Tetracycline on the MnFeO/BGA Composite under Visible Light.International Journal of Molecular... May 2023In this work, the MnFeO/BGA (boron-doped graphene aerogel) composite prepared via the solvothermal method is applied as a photocatalyst to the degradation of...
In this work, the MnFeO/BGA (boron-doped graphene aerogel) composite prepared via the solvothermal method is applied as a photocatalyst to the degradation of tetracycline in the presence of peroxymonosulfate. The composite's phase composition, morphology, valence state of elements, defect and pore structure were analyzed by XRD, SEM/TEM, XPS, Raman scattering and N adsorption-desorption isotherms, respectively. Under the radiation of visible light, the experimental parameters, including the ratio of BGA to MnFeO, the dosages of MnFeO/BGA and PMS, and the initial pH and tetracycline concentration were optimized in line with the degradation of tetracycline. Under the optimized conditions, the degradation rate of tetracycline reached 92.15% within 60 min, whereas the degradation rate constant on MnFeO/BGA remained 4.1 × 10 min, which was 1.93 and 1.56 times of those on BGA and MnFeO, respectively. The largely enhanced photocatalytic activity of the MnFeO/BGA composite over MnFeO and BGA could be ascribed to the formation of type I heterojunction on the interfaces of BGA and MnFeO, which leads to the efficient transfer and separation of photogenerated charge carriers. Transient photocurrent response and electrochemical impedance spectroscopy tests offered solid support to this assumption. In line with the active species trapping experiments, SO and O radicals are confirmed to play crucial roles in the rapid and efficient degradation of tetracycline, and accordingly, a photodegradation mechanism for the degradation of tetracycline on MnFeO/BGA is proposed.
Topics: Catalysis; Anti-Bacterial Agents; Tetracycline; Photolysis; Light
PubMed: 37298330
DOI: 10.3390/ijms24119378 -
Molecules (Basel, Switzerland) Aug 2019Thione-containing nucleobases have attracted the attention of the scientific community for their application in oncology, virology, and transplantology. The detailed...
Thione-containing nucleobases have attracted the attention of the scientific community for their application in oncology, virology, and transplantology. The detailed understanding of the reactivity of the purine derivative 8-thioguanosine (8-TG) with reactive oxygen species (ROS) and free radicals is crucial for its biological relevance. An extensive investigation on the fate of 8-TG under both reductive and oxidative conditions is here reported, and it was tested by employing steady-state photooxidation, laser flash photolysis, as well as γ-radiolysis in aqueous solutions. The characterization of the 8-TG T excited state by laser flash photolysis and the photooxidation experiments confirmed that singlet oxygen is a crucial intermediate in the formation of the unexpected reduced product guanosine, without the formation of the usual oxygenated sulfinic or sulfonic acids. Furthermore, a thorough screening of different radiolytic conditions upon γ-radiation afforded the reduced product. These results were rationalized by performing control experiments in the predominant presence of each reactive species formed by radiolysis of water, and the mechanistic pathway scenario was postulated on these bases.
Topics: Guanosine; Kinetics; Lasers; Light; Oxidation-Reduction; Photolysis; Pulse Radiolysis; Singlet Oxygen; Solutions; Thionucleosides; Water
PubMed: 31470553
DOI: 10.3390/molecules24173143 -
The Journal of Physical Chemistry... Aug 2022It is well-known that photolysis of pyrimidine nucleobases, such as uracil, in an aqueous environment results in the formation of hydrate as one of the main products....
It is well-known that photolysis of pyrimidine nucleobases, such as uracil, in an aqueous environment results in the formation of hydrate as one of the main products. Although several hypotheses regarding photohydration have been proposed in the past, e.g., the zwitterionic and "hot" ground-state mechanisms, its detailed mechanism remains elusive. Here, theoretical nonadiabatic simulations of the uracil photodynamics reveal the formation of a highly energetic but kinetically stable intermediate that features a half-chair puckered pyrimidine ring and a strongly twisted intracyclic double bond. The existence and the kinetic stability of the intermediate are confirmed by a variety of computational chemistry methods. According to the simulations, the unusual intermediate is mainly formed almost immediately (∼50-200 fs) upon photoabsorption and survives long enough to engage in a hydration reaction with a neighboring water. A plausible mechanism of uracil photohydration is proposed on the basis of the modeling of nucleophilic insertion of water into the twisted double bond of the intermediate.
Topics: Kinetics; Photolysis; Pyrimidines; Uracil; Water
PubMed: 35900137
DOI: 10.1021/acs.jpclett.2c01694 -
Organic & Biomolecular Chemistry Mar 2021Photoactivatable protecting groups (PPGs) are useful for a broad range of applications ranging from biology to materials science. In chemical biology, induction of...
Photoactivatable protecting groups (PPGs) are useful for a broad range of applications ranging from biology to materials science. In chemical biology, induction of biological processes via photoactivation is a powerful strategy for achieving spatiotemporal control. The importance of cysteine, glutathione, and other bioactive thiols in regulating protein structure/activity and cell redox homeostasis makes modulation of thiol activity particularly useful. One major objective for enhancing the utility of photoactivatable protecting groups (PPGs) in living systems is creating PPGs with longer wavelength absorption maxima and efficient two-photon (TP) absorption. Toward these objectives, we developed a carboxyl- and dimethylamine-functionalized nitrodibenzofuran PPG scaffold (cDMA-NDBF) for thiol photoactivation, which has a bathochromic shift in the one-photon absorption maximum from λmax = 315 nm with the unfunctionalized NDBF scaffold to λmax = 445 nm. While cDMA-NDBF-protected thiols are stable in the presence of UV irradiation, they undergo efficient broad-spectrum TP photolysis at wavelengths as long as 900 nm. To demonstrate the wavelength orthogonality of cDMA-NDBF and NDBF photolysis in a biological setting, caged farnesyltransferase enzyme inhibitors (FTI) were prepared and selectively photoactivated in live cells using 850-900 nm TP light for cDMA-NDBF-FTI and 300 nm UV light for NDBF-FTI. These experiments represent the first demonstration of thiol photoactivation at wavelengths above 800 nm. Consequently, cDMA-NDBF-caged thiols should have broad applicability in a wide range of experiments in chemical biology and materials science.
Topics: Animals; Benzofurans; Dogs; Enzyme Inhibitors; Farnesyltranstransferase; Infrared Rays; Madin Darby Canine Kidney Cells; Photolysis; Photons; Sulfhydryl Compounds
PubMed: 33349821
DOI: 10.1039/d0ob01986k -
The Science of the Total Environment Aug 2022Estrogens are endocrine disrupting chemicals that have been frequently detected in diverse water matrices (e.g. surface water, wastewater and drinking water) and caused...
Estrogens are endocrine disrupting chemicals that have been frequently detected in diverse water matrices (e.g. surface water, wastewater and drinking water) and caused a series of health risks. This study was aimed at investigating the photochemical degradation of free estrogens estrone (E1), 17β-estradiol (E2), estriol (E3), and 17α-ethyl estradiol (EE2) upon the monochromatic irradiation (253.7 nm). Concerning the practical installation of photolysis treatment, exposing the impacts of photoreactor operation mode (stationary or up-flow) and the water matrix (ultrapure water or natural surface water) on the photolytic behaviour of estrogens was of high importance. The pseudo-first-order rate constants showed that E1 was the most susceptible to UV radiation among chosen estrogens due to its high molar absorption coefficient of 402.4 M cm and quantum yield of 0.065 mol E at λ = 253.7 nm. Moreover, the up-flow mode and the surface water matrix collected from a lake in Regent's Park (London) were found to favour the photodegradation of estrogens due to the introduction of more dissolved oxygens and promotion of reactive oxygen species (ROS) formation. These findings may shed light on the photochemical behaviour of estrogens in some specific scenarios.
Topics: Drinking Water; Estradiol; Estrogens; Estrone; Ethinyl Estradiol; Photolysis; Ultraviolet Rays; Water Pollutants, Chemical
PubMed: 35489505
DOI: 10.1016/j.scitotenv.2022.155515 -
Molecules (Basel, Switzerland) Feb 2022-nitrosothiols are labile thiol-NO adducts formed in vivo primarily by metalloproteins such as NO synthase, ceruloplasmin, and hemoglobin. Abnormal -nitrosothiol...
-nitrosothiols are labile thiol-NO adducts formed in vivo primarily by metalloproteins such as NO synthase, ceruloplasmin, and hemoglobin. Abnormal -nitrosothiol synthesis and catabolism contribute to many diseases, ranging from asthma to septic shock. Current methods for quantifying -nitrosothiols in vivo are suboptimal. Samples need to be removed from the body for analysis, and the -nitrosothiols can be broken down during ex vivo processing. Here, we have developed a noninvasive device to measure mammalian tissue -nitrosothiols in situ non-invasively using ultraviolet (UV) light, which causes NO release in proportion to the -nitrosothiol concentration. We validated the assay in vitro; then, we applied it to measure -nitrosothiols in vivo in rats and in humans. The method was sensitive to 0.5 µM, specific (did not detect other nitrogen oxides), and was reproducible in rats and in humans. This noninvasive approach to -nitrosothiol measurements may be applicable for use in human diseases.
Topics: Animals; Female; Humans; Luminescent Measurements; Male; Molecular Structure; Nitrogen Oxides; Organ Specificity; Photolysis; Rats; S-Nitrosothiols; Ultraviolet Rays
PubMed: 35209089
DOI: 10.3390/molecules27041294