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Journal of the American Chemical Society Jan 2020We accidentally found that YM-53601, a known small-molecule inhibitor of squalene synthase (SQS), selectively depletes SQS from mammalian cells upon UV irradiation....
We accidentally found that YM-53601, a known small-molecule inhibitor of squalene synthase (SQS), selectively depletes SQS from mammalian cells upon UV irradiation. Further analyses indicated that the photodepletion of SQS requires its short peptide segment located at the COOH terminus. Remarkably, when the 27 amino acid peptide was fused to green fluorescent protein or unrelated proteins at either the NH or COOH terminus, such fusion proteins were selectively depleted when the cells were treated with both YM-53601 and UV exposure. Product analysis and electron spin resonance experiments suggested that the UV irradiation promotes homolytic C-O bond cleavage of the aryl ether group in YM-53601. It is likely that the radical species generated from UV-activated YM-53601 abstract hydrogen atoms from the SQS peptide, leading to the photolysis of the entire protein. The pair of the SQS peptide and YM-53601 discovered in the present study paves the way for the design of a new small-molecule-controlled optogenetic tool.
Topics: Farnesyl-Diphosphate Farnesyltransferase; HEK293 Cells; Humans; Peptides; Photolysis; Quinuclidines
PubMed: 31899620
DOI: 10.1021/jacs.9b09178 -
Purinergic Signalling Sep 2021Purinergic signaling plays a pivotal role in physiological processes and pathological conditions. Over the past decades, conventional pharmacological, biochemical, and... (Review)
Review
Purinergic signaling plays a pivotal role in physiological processes and pathological conditions. Over the past decades, conventional pharmacological, biochemical, and molecular biology techniques have been utilized to investigate purinergic signaling cascades. However, none of them is capable of spatially and temporally manipulating purinergic signaling cascades. Currently, optical approaches, including optopharmacology and optogenetic, enable controlling purinergic signaling with low invasiveness and high spatiotemporal precision. In this mini-review, we discuss optical approaches for controlling purinergic signaling and their applications in basic and translational science.
Topics: Adenosine Triphosphate; Animals; Humans; Optogenetics; Photolysis; Receptors, Purinergic; Signal Transduction
PubMed: 34156578
DOI: 10.1007/s11302-021-09799-2 -
ChemistryOpen Aug 2020Bioorthogonal reactions including the bioorthogonal ligations and cleavages have become an active field of research in chemical biology, and they play important roles in... (Review)
Review
Bioorthogonal reactions including the bioorthogonal ligations and cleavages have become an active field of research in chemical biology, and they play important roles in chemical modification and functional regulation of biomolecules. This review summarizes the developments and applications of the representative bioorthogonal reactions including the Staudinger reactions, the metal-mediated bioorthogonal reactions, the strain-promoted cycloadditions, the inverse electron demand Diels-Alder reactions, the light-triggered bioorthogonal reactions, and the reactions of chloroquinoxalines and -dithiophenols.
Topics: Alkynes; Azides; Catalysis; Cycloaddition Reaction; Heterocyclic Compounds, 1-Ring; Light; Metals, Heavy; Phosphines; Photolysis; Quinoxalines; Sulfhydryl Compounds
PubMed: 32817809
DOI: 10.1002/open.202000128 -
Ecotoxicology and Environmental Safety Jun 2023Triclosan (TCS) is omnipresent in the environment and has drawn increasing attention due to its potential adverse effects on human health. Direct photolysis of TCS...
Triclosan (TCS) is omnipresent in the environment and has drawn increasing attention due to its potential adverse effects on human health. Direct photolysis of TCS readily occurs, especially in the surface layers of waters that receive abundant ultraviolet radiation during the daytime. However, biological concerns and the identification of toxic products during TCS photolysis have been explored limitedly. Therefore, in the present work, the structural characterization of the photolysis products by UVC and UVA were performed based on the mass spectra and fragmental ions. The results displayed that TCS was more readily eliminated by UVC than UVA, and the product species were completely different when TCS was degraded by UVC and UVA, respectively. Two products, m/z 235 and m/z 252, were produced via reductive dechlorination and nucleophilic substitution with UVC, while three dioxin-like isomer products were generated by dechlorination, cyclization and hydroxylation. Furthermore, the results of biological concerns suggested that the elimination of TCS did not represent the disappearance of biological risks. Specifically, more hazardous and photolysis products were formed during TCS photolysis with ultraviolets. For instance, the dioxin-like isomer products were highly microtoxic and genotoxic, and mildly antiestrogenic. The positive findings highlighted the biological concerns of TCS photolysis by ultraviolet radiation in the aquatic environment.
Topics: Humans; Triclosan; Ultraviolet Rays; Photolysis; Dioxins; Mass Spectrometry; Water Pollutants, Chemical
PubMed: 37167739
DOI: 10.1016/j.ecoenv.2023.114998 -
Sensors (Basel, Switzerland) Mar 2022Molecular communication (MC) is a promising bioinspired paradigm for exchanging molecule information among nanomachines. In this paper, we propose a...
Molecular communication (MC) is a promising bioinspired paradigm for exchanging molecule information among nanomachines. In this paper, we propose a synchronization-assist photolysis MC system that aims to transmit the biosensing signal of the tumor microenvironment, facilitated by mitigating redundant molecules for improved bit error rate (BER) performance. Benefits from biocompatible MC, biosensors could transmit biosensing signals of the tumor in vivo instead of converting them to electrical signals. Due to diffusion motion's slow and stochastic nature, intersymbol interference (ISI), resulting from previous symbols' residual information molecules, inevitably occurs in diffusion-based MC. ISI is one of the challenges in diffusion-based MC, which significantly impacts signal detection. Inspired by on-off keying (OOK) modulation, the proposed modulation implements a switch of molecules and light alternatively. The light emitted is triggered by a synchronization signal, and the photolysis reactions could reduce the redundant molecules. An expression for the relevant channel impulse response (CIR) is derived from a hybrid channel model of diffusion and photolysis reaction. In this paper, we implement the maximum posterior estimation scheme to find the optimal decision threshold and analysis the BER performance in terms of different time intervals of the system. Numerical simulations demonstrate that the proposed method can improve the channel capacity and BER performance. We believe that our work may pave the way for MC application in biosensing.
Topics: Communication; Computers, Molecular; Humans; Nanotechnology; Neoplasms; Photolysis; Tumor Microenvironment
PubMed: 35408108
DOI: 10.3390/s22072495 -
Chemosphere Jan 2022Colloids, such as natural particulate matter and microplastics, can play a significant role in the fate and transport of organic contaminants. Specifically, these small...
Colloids, such as natural particulate matter and microplastics, can play a significant role in the fate and transport of organic contaminants. Specifically, these small nano-to micron-sized particles provide large surface area; thus, particle-aqueous interfacial chemistry becomes significant. In this work, we present an experimental investigation of interfacial photokinetics of malachite green cation (MG) adsorbed at the surface of polystyrene carboxyl (PSC) microspheres suspended in aqueous solution. Second harmonic generation (SHG), an interfacial selective laser spectroscopic tool, has been used to probe the buried interface. It is revealed that relative to the bulk, photoinduced degradation of MG is accelerated by approximately 10-fold at this noncatalytic particle surface. By measuring the SHG-based surface electronic spectra, we have also demonstrated that N-demethylated intermediates of MG remain at the interface until they are further decomposed. MG exhibits a bathochromic shift at the interface. Together with strong binding affinity and faster initial rate of photodegradation of MG at the interface, this work highlights that adsorption and surface photolysis are important pathways by which organic compounds can be transformed within the aquatic environment. Moreover, this research also stimulates further questions on the enrichment of reactive species at the colloidal-aqueous interface and their influence on facilitating decompositions of organic pollutants.
Topics: Microplastics; Photolysis; Plastics; Rosaniline Dyes
PubMed: 34461340
DOI: 10.1016/j.chemosphere.2021.131953 -
Environmental Science and Pollution... Jan 2017Consumption of psychotropic drugs is still increasing, especially in high-income countries. One of the most crucial consequences of this fact is significant release of... (Review)
Review
Consumption of psychotropic drugs is still increasing, especially in high-income countries. One of the most crucial consequences of this fact is significant release of them to the environment. Considerable amounts of atypical antipsychotics, benzodiazepines, antidepressants, and their metabolites were detected in river, lake, and sea water, as well as in tissues of aquatic organisms. Their ecotoxicity was proved by numerous studies. It should be noticed that interaction between psychotropic pharmaceuticals and radiation may lead to formation of potentially more toxic intermediates. On the other hand, photo-assisted wastewater treatment methods can be used as an efficient way to eliminate them from the environment. Many methods based on photolysis and photocatalysis were proposed and developed recently; nevertheless, the problem is still unsolved. However, according to recent studies, photocatalysis could be considered as the most promising and far more effective than regular photolysis. An overview on photolytic as well as homogenous and heterogeneous photocatalytic degradation methods with the use of various catalysts is presented. The photostability and phototoxicity of pharmaceuticals were also discussed. Various analytical methods were used for the photodegradation research, and this issue was also compared and summarized. Use of high-resolution multistage mass spectrometry (Q-TOF, ion trap, Orbitrap) was suggested. The combined techniques such as LC-MS, GC-MS, and LC-NMR, which enable qualitative and quantitative analyses in one run, proved to be the most valuable in this case. Assembling of MS/MS spectra libraries of drug molecules and their phototransformation products was identified as the future challenge.
Topics: Chromatography, Liquid; Photolysis; Psychotropic Drugs; Rivers; Tandem Mass Spectrometry; Wastewater; Water Pollutants, Chemical; Water Purification
PubMed: 27696160
DOI: 10.1007/s11356-016-7727-5 -
Molecules (Basel, Switzerland) Apr 2022Carvone is a monoterpene compound that has been widely used as a pesticide for more than 10 years. However, little is known regarding the fate of carvone, or its...
Carvone is a monoterpene compound that has been widely used as a pesticide for more than 10 years. However, little is known regarding the fate of carvone, or its degradation products, in the environment. We used GC-MS (gas chromatography-mass spectrometry) to study the fate of carvone and its degradation and photolysis products under different soil and light conditions. We identified and quantified three degradation products of carvone in soil and water samples: dihydrocarvone, dihydrocarveol, and carvone camphor. In soil, dihydrocarveol was produced at very low levels (≤0.067 mg/kg), while dihydrocarvone was produced at much higher levels (≤2.07 mg/kg). In water exposed to differing light conditions, carvone was degraded to carvone camphor. The photolysis rate of carvone camphor under a mercury lamp was faster, but its persistence was lower than under a xenon lamp. The results of this study provide fundamental data to better understand the fate and degradation of carvone and its metabolites in the environment.
Topics: Camphor; Cyclohexane Monoterpenes; Photolysis; Soil; Water; Water Pollutants, Chemical
PubMed: 35458614
DOI: 10.3390/molecules27082415 -
Photochemistry and Photobiology Mar 2022The photolysis reactions of (8-cyano-7-hydroxyquinolin-2-yl)methyl (CyHQ)-caged amines have been investigated using time-resolved spectroscopy methods. Unexpectedly, an...
The photolysis reactions of (8-cyano-7-hydroxyquinolin-2-yl)methyl (CyHQ)-caged amines have been investigated using time-resolved spectroscopy methods. Unexpectedly, an unconventional Hofmann-Martius rearrangement reaction with high yield and regioselectivity occurred during the photolysis of some CyHQ-protected dialkylanilines (such as compounds 1a and 2a). To have more insights into the mechanism of this unexpected photorearrangement reaction, we characterized the reaction intermediates directly using time-resolved spectroscopy. Our new results showed that the anionic form of compound 1a was photoexcited to the singlet excited state, then a heterolytic cleavage of the C-N bond took place to give CyHQ and the corresponding aniline. Thereafter, the recombined intermediate 6 was found to appear in about 19.7 and 44.3 ps for 1a (A) and 2a (A), respectively, before the generation of an ortho-substituted aniline (1b and 2b) via the excited-state deprotonation of 6. Thus, a logical photodynamic mechanism of this photoinduced Hofmann-Martius rearrangement reaction was deduced. This new insight into the reaction mechanisms may be helpful for the design of novel related photoactivatable aniline molecules and for understanding other similar photorearrangement reaction mechanisms.
Topics: Amines; Aniline Compounds; Photolysis; Quinolines; Spectrum Analysis
PubMed: 34812490
DOI: 10.1111/php.13566 -
Environmental Science & Technology Sep 2022The photolysis of pesticides with different fluorine motifs was evaluated to quantify the formation of fluorinated products in buffered aqueous systems, advanced...
The photolysis of pesticides with different fluorine motifs was evaluated to quantify the formation of fluorinated products in buffered aqueous systems, advanced oxidation (AOP) and reduction processes (ARP), and river water. Simulated sunlight quantum yields at pH 7 were 0.0033, 0.0025, 0.0015, and 0.00012 for penoxsulam, florasulam, sulfoxaflor, and fluroxypyr, respectively. The bimolecular rate constants with hydroxyl radicals were 2 to 5.7 × 10 M s and, with sulfate radicals, 1.6 to 2.6 × 10 M s for penoxsulam, florasulam, and fluroxypyr, respectively. The rate constants of sulfoxaflor were 100-fold lower. Using quantitative F-NMR, complete fluorine mass balances were obtained. The maximum fluoride formation was 53.4 and 87.4% for penoxsulam and florasulam under ARP conditions, and 6.1 and 100% for sulfoxaflor and fluroxypyr under AOP conditions. Heteroaromatic CF and aliphatic CF groups were retained in multiple fluorinated photoproducts. Aryl F and heteroaromatic F groups were readily defluorinated to fluoride. CF and CF groups formed trifluoroacetate and difluoroacetate, and yields increased under oxidizing conditions. F-NMR chemical shifts and coupling analysis provided information on hydrogen loss on adjacent bonds or changes in chirality. Mass spectrometry results were consistent with the observed F-NMR products. These results will assist in selecting treatment processes for specific fluorine motifs and in the design of agrochemicals to reduce byproduct formation.
Topics: Fluorides; Fluorine; Hydroxyl Radical; Pesticides; Photolysis
PubMed: 35972505
DOI: 10.1021/acs.est.2c04242