Photochemistry and Photobiology最新文献

{"title":"Selective photo labeling of tryptophan in N-acetyl-L-tryptophan ethyl ester and peptide WWCNDGR with a diaryl nitrenium ion.","authors":"Edward S Chinn, Yue Li, Abigail M Joyce, Daniel E Falvey","doi":"10.1111/php.70109","DOIUrl":"https://doi.org/10.1111/php.70109","url":null,"abstract":"<p><p>Diaryl nitrenium ions are short-lived electrophiles that have been shown to react rapidly with various nucleic and amino acids. To determine whether these species could be used to covalently photomodify proteins or peptides, a diarylnitrenium ion precursor, N-(4,4'-dibromodiphenylamino)-2,4,6-trimethylpyridinium ion, was photolyzed in the presence of tryptophan as well as a tryptophan-containing peptide (WWCNDGR). It is shown that the resulting diarylnitrenium ion, N-(4,4'-dibromodiphenyl)nitrenium ion, forms two covalent adducts with tryptophan, the first where the ortho-ring carbon of the nitrenium ion couples to the C-2 of the tryptophan and a second isomer where the indole N-1 nitrogen of tryptophan couples to the ortho-ring carbon of the nitrenium ion. When photolyzed in the presence of the peptide, tandem mass spectrometry demonstrates selective formation of adducts on the tryptophan residues. Laser flash photolysis experiments verify that trapping occurs via a nitrenium ion intermediate.</p>","PeriodicalId":20133,"journal":{"name":"Photochemistry and Photobiology","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148056130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photodegradation of commercial insect repellents containing DEET and IR-3535 under ultraviolet light associated or not with chemical ultraviolet filters evaluated by Raman spectroscopy.","authors":"Viviane Gadret Borio, Adriana Barrinha Fernandes, Leandro Procópio Alves, Adjaci Uchôa Fernandes, Landulfo Silveira","doi":"10.1111/php.70117","DOIUrl":"https://doi.org/10.1111/php.70117","url":null,"abstract":"<p><p>The use of insect repellents in areas with high solar radiation exposure has increased significantly due to dengue and chikungunya epidemics in Brazil. However, limited research exists on the photostability of these substances under ultraviolet (UV) radiation. This study aimed to evaluate the photolability of two common insect repellents, N,N-diethyl-3-methylbenzamide (DEET) and ethyl 3-[acetyl(butyl)amino]propanoate (IR-3535), and commercial products containing these active ingredients, including combinations with selected chemical UV filters, under simulated UV radiation using Raman spectroscopy. Samples were exposed to a UV-A + UV-B light source (7.0 mW/cm²) for 8 h, and Raman spectra were collected before and after irradiation. Pure DEET, IR-3535, ethanol, isopropyl myristate, and the commercial product containing IR-3535 exhibited no significant spectral changes following UV exposure. In contrast, DEET diluted in ethanol and the commercial product containing DEET exhibited significant changes, including a decrease in DEET peaks at 524, 690, 1003, and 1606 cm^-1 and an increase in the ethanol peak at 884 cm^-1. When UV filters were added to the commercial products containing DEET and IR-3535, no significant changes were observed in the peaks associated with DEET, IR-3535, or ethanol. However, alterations were observed in the spectra of the UV filters, suggesting that the filters conferred photoprotection to the repellent molecules via a competitive photon absorption mechanism, but also exhibited photodegradation of their own molecules. These findings suggest that the commercial product containing DEET is photolabile under UV exposure and that the inclusion of chemical UV filters can restore photostability.</p>","PeriodicalId":20133,"journal":{"name":"Photochemistry and Photobiology","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148034159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of photobiomodulation using red LED (630 nm) on the metabolism of human osteoblasts.","authors":"Fernando César Moreira, Martha Simões Ribeiro, Carlos Alberto de Souza Costa, Taisa Nogueira Pansani, Helder Baldi Jacob","doi":"10.1111/php.70111","DOIUrl":"https://doi.org/10.1111/php.70111","url":null,"abstract":"<p><p>Photobiomodulation (PBM) using red LED light (630 nm) has been investigated for its ability to modulate cellular functions relevant to tissue regeneration. This in vitro study evaluated the effects of PBM on the viability, metabolism, and migration of human osteoblast-like SAOS-2 cells. Cultures were irradiated with fluences of 2, 4, or 6 J cm^-2 in three applications spaced 12 h apart and compared with a nonirradiated control. Cell viability, total protein production, alkaline phosphatase (ALP) activity, collagen synthesis, mineralized nodule formation, and wound-closure migration were assessed at 7 and 14 days. PBM did not alter viability. Total protein and collagen synthesis increased at day 14, with significantly greater collagen levels at 6 J cm^-2. ALP activity peaked at day 7 and declined thereafter; at day 7, the 2 and 6 J cm^-2 groups showed lower ALP levels than the control group, while mineralization increased over time in all groups without any between-group differences. Migration was greatest at 2 J cm^-2, and SEM images revealed higher cell density at 6 J cm^-2. These dose-dependent responses indicate distinct PBM-sensitive stages in osteoblast physiology, supporting biological rationale for parameter selection in future PBM protocols targeting bone repair and craniofacial applications.</p>","PeriodicalId":20133,"journal":{"name":"Photochemistry and Photobiology","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148016751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploration of the protective effects of ginkgo biloba extract against UVA-induced skin Photoaging in mice.","authors":"Xiang Li, Ping Wang, Runzhu Huang, Lei Luo, Ying Xie","doi":"10.1111/php.70105","DOIUrl":"https://doi.org/10.1111/php.70105","url":null,"abstract":"<p><p>Ultraviolet A (UVA) intensity in daily life is a significant risk factor for skin photoaging. Ginkgo biloba extract (GBE), a plant-derived natural extract widely used in clinical practice, has been reported to reduce oxidative damage under various pathological conditions, including diabetes, ischemic injury, and neurodegeneration. These findings suggest that GBE may also protect the skin against UVA-induced oxidative damage and photoaging. In this study, a UVA-induced photoaging model was established by applying 1% 8-methoxypsoralen (8-MOP) to the dorsal skin of mice two hours before each UVA exposure to enhance photosensitivity. The mice were then exposed to UVA radiation for seven consecutive days with a cumulative dose of 110 J/cm², while GBE was administered orally (100 mg/kg/day) prior to and during UVA irradiation. Skin oxidative stress markers, collagen degradation, and plasma inflammatory cytokines (TNF-α, IL-1β, COX-2, IL-6) were analyzed, and Western blotting was used to assess MAPK pathway activation (ERK, JNK, p38), NF-κB nuclear translocation, and the expression of c-Jun, c-Fos, and matrix metalloproteinases (MMP-1, MMP-3, MMP-9). UVA/8-MOP exposure significantly enhanced oxidative stress, inflammatory responses, and MMP expression, activating MAPK and NF-κB pathways, whereas GBE treatment markedly alleviated these effects and preserved collagen structure. These findings suggest that GBE exerts protective potential against UVA/8-MOP-induced skin photoaging by mitigating oxidative stress, enhancing endogenous defense mechanisms, reducing free radical damage to biomolecules such as DNA and proteins, and suppressing inflammation, supporting its possible application as a therapeutic candidate for anti-photoaging interventions.</p>","PeriodicalId":20133,"journal":{"name":"Photochemistry and Photobiology","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147964625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Translating societal observations into photochemical and biophysical innovations: Concept-driven strategies for quality research.","authors":"Pronab Kundu, Debosreeta Bose, Nitin Chattopadhyay","doi":"10.1111/php.70114","DOIUrl":"https://doi.org/10.1111/php.70114","url":null,"abstract":"&lt;p&gt;&lt;p&gt;New entrants in scientific research often presume that quality and impactful research requires access to sophisticated and expensive instrumentation, resulting in discouragement for laboratories with limited in-house facilities. The present review, principally based on our laboratory work, challenges this concept by demonstrating that the foundation of meaningful research lies, to a good extent, in keen societal observation, inquisitiveness, logical analysis, and rationalization, rather than mere instrumentation; although none can ignore the complementary role and impact of tailor-made and other contemporary instrumentation when accessible. Through a series of conceptually driven strategies, largely developed in our laboratory, this review demonstrates how judiciously designed simple, strategic experimental techniques can yield productive, innovative, and socially relevant outcomes across photochemistry, biophysical chemistry, and general chemistry. The present review reports a breakthrough in using micelles as \"broker\" to improve the sensing ability of a fluorosensor toward biologically and environmentally relevant analytes such as Cu&lt;sup&gt;2+&lt;/sup&gt; by orders of magnitude, achieved simply by exploiting absorption and fluorescence spectroscopy; the first-ever demonstration of a cationic sensor detecting a cationic analyte in aqueous medium; selective detection of the highly toxic cyanide ion in water employing merely an absorption spectrophotometer; a low-cost strategy for the synthesis of gold nanoparticles of desired dimensions, where particle size can be measured using routine UV-vis spectrophotometry, rather than advanced and costly instruments such as TEM and SEM. This review further presents concept-based fundamental advances in molecular photophysics, including discovery and mechanistic understanding of S&lt;sub&gt;2&lt;/sub&gt; emission in some 1,2-dicarbonyl compounds, elucidation of asymmetric solvation of ESIPT-prone probes in protic solvents, and innovative strategies to overcome the spectral overlap constraint in Förster resonance energy transfer (FRET) by coupling it with other photoprocesses such as excited-state proton transfer (ESPT) or intramolecular charge transfer (ICT). Further, development of multifunctional composite hydrogels exhibiting exceptionally high proton conductivities is discussed, alongside novel mechanistically guided strategies like electrostatic pushing, micelle-mediated switchability of endogenous/exogenous modes for targeted drug delivery and cyclodextrin-assisted excretion of accumulated drugs from the cell membranes are presented. Collectively, these studies demonstrate how rational translation of societal observations into fundamental chemical principles can provide a balanced and realistic framework for conducting quality research by integrating conceptual innovation, accessible methodologies, and collaborative use of advanced infrastructure. The central objective of this review was to motivate early-career rese","PeriodicalId":20133,"journal":{"name":"Photochemistry and Photobiology","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147942603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Methods for substituting onsite ambient ultraviolet radiation measurements for personal exposure studies.","authors":"F Lubitz, S Helletzgruber, H Danhel, D Radmanovac, A Dzwonek, E Kitz, P Weihs, A W Schmalwieser","doi":"10.1111/php.70108","DOIUrl":"https://doi.org/10.1111/php.70108","url":null,"abstract":"<p><p>Measurements of personal ultraviolet radiation (UVR) exposure are a helpful tool in estimating people's UVR exposure. Gained values are valid for the corresponding location, time and date only. Assessment of personal UVR exposure as well as its translation to other locations, times and dates require ambient UVR as a reference. In some cases, UVR measurements are not available at the study site for practical reasons. Therefore, we have investigated alternative methods to substitute on-site measurements of ambient erythemally weighted daily radiant exposure. These methods comprise the assumption of spatial persistency of measurements from distant high-grade instruments, model calculations including clouds (TEMIS) and satellite measurements (OMI). Evaluation was done by substituting measurements of a high-grade instrument operated in Vienna, Austria. Our results show that up to a distance of 82 km the assumption of spatial persistency delivers lowest uncertainties. For larger distances, TEMIS performs better. Substituting with OMI carries the highest uncertainty but is the only method with global coverage, and therefore the only applicable method in large parts of the world. For correction of altitude, an increase of +14%/1000 m was found for clear sky, but for all-sky, monthly medians up to +40%/1000 m were found.</p>","PeriodicalId":20133,"journal":{"name":"Photochemistry and Photobiology","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147932455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Topical amnion-derived mesenchymal stem cell conditioned medium attenuates chronic ultraviolet B-induced skin photodamage in hairless mice.","authors":"Shintaro Mitamura, Kosuke Ishikawa, Hiroko Takahashi, Yuki Sasaki, Shunsuke Ohnishi, Taku Maeda","doi":"10.1111/php.70112","DOIUrl":"https://doi.org/10.1111/php.70112","url":null,"abstract":"<p><p>Ultraviolet B (UVB) exposure induces epidermal hyperplasia, wrinkle formation, and stress-associated responses; however, practical topical countermeasures remain limited. This exploratory proof-of-concept study evaluated whether topical amnion-derived mesenchymal stem cell conditioned medium (AMSC-CM) attenuates chronic UVB-induced photodamage in hairless mice. Male Hos:HR-1 hairless mice were exposed to escalating UVB doses three times per week for 10 weeks and received no topical treatment, α-minimum essential medium (αMEM) vehicle gel, or AMSC-CM gel immediately after each irradiation session; a nonirradiated group served as a control. Wrinkle severity was graded on endpoint dorsal photographs by a masked evaluator, and skin sections were analyzed for epidermal and dermal thickness and epidermal p21 immunoreactivity. UVB exposure increased wrinkle scores, epidermal thickness, and epidermal p21 positivity relative to nonirradiated controls. Compared with UVB alone, AMSC-CM significantly reduced wrinkle severity (mean score 2.00 vs. 4.50; Holm-adjusted p = 0.035). By contrast, epidermal thickness and epidermal p21 positivity showed directional but nonsignificant reductions after Holm correction. These findings support wrinkle attenuation as the primary statistically supported outcome of this exploratory proof-of-concept study and suggest that topical AMSC-CM may modulate chronic UVB-induced photodamage under controlled dosimetry, while secondary histological and p21-related observations remain preliminary.</p>","PeriodicalId":20133,"journal":{"name":"Photochemistry and Photobiology","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147869327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Circadian regulation of reproduction and neoblast cell division in the catenulid flatworm Stenostomum virginianum (Platyhelminthes).","authors":"Daniel L Stanton, Ian D Deas, J Kennon Smith, Samuel B Robinson, Adam M Reitzel, Julian P S Smith","doi":"10.1111/php.70100","DOIUrl":"https://doi.org/10.1111/php.70100","url":null,"abstract":"<p><p>The molecular circadian clock and melatonin secretion are pivotal for coordinating homeostasis pathways in many animals. Melatonin has been shown to regulate reproduction and neoblast proliferation in triclad flatworms, yet the extent to which these mechanisms operate in other platyhelminths remains unknown. We examined light sensing, endogenous melatonin production, and circadian control of asexual reproduction in the early-branching catenulid Stenostomum virginianum. Microscopy revealed refractile bodies with photoreceptor-like structures, blue-light autofluorescence, and PAX6 immunoreactivity in cells anterior to the brain that support the presence of a photoreceptive system. High-performance liquid chromatography detected endogenous melatonin production in S. virginianum. Exogenous melatonin administered under continuous darkness suppressed reproduction and neoblast mitosis. The same treatment applied at ZT 6 during a 12 h:12 h light-dark cycle failed to affect reproduction, implying a masking or circadian compensatory effect. Phylogenetic analysis identified two broadly conserved bHLH-PAS genes (ARNT) in a transcriptome for S. virginianum; although CLOCK and CRY were not detected, they are present in the closely related Macrostomum lignano, indicating that this absence may be due to an incomplete transcriptome. These findings suggest that circadian rhythms influence reproduction and cell division in S. virginianum, extending our understanding of melatonin-mediated, light-responsive regulation in distinct branches of the platyhelminths.</p>","PeriodicalId":20133,"journal":{"name":"Photochemistry and Photobiology","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147841656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond Plasmonic expectations: Micellar confinement governs the Norrish type I reaction in hybrid micelle-gold nanoparticle systems.","authors":"Nory Mariño-Ocampo, Yousif Rawof, John Vincent Malvar, Jacky Kieu, Belinda Heyne","doi":"10.1111/php.70107","DOIUrl":"https://doi.org/10.1111/php.70107","url":null,"abstract":"<p><p>Spin-dependent photochemical mechanisms are central to understanding how external stimuli, such as light, temperature, and magnetic fields, modulate chemical reactivity. In this study, the photolysis of the asymmetrical ketone 4-methyldibenzyl ketone (MDBK) was investigated in cetyltrimethylammonium chloride (CTAC) micelles and in hybrid gold nanoparticle (AuNP) systems under UVB and combined UVB-red light irradiation. The objective was to assess whether plasmonic AuNPs could alter product distribution or influence radical pathways relative to micellar media alone. Photoproduct analysis revealed that the incorporation of AuNPs did not induce measurable variations in the product ratios, and the calculated cage effect remained comparable to that observed in pure CTAC micelles. This outcome demonstrates that micellar confinement remains the dominant factor controlling radical recombination in MBDK photolysis, even in hybrid plasmonic environments. By defining the regime in which nanoparticle-induced perturbations are negligible, this work provides a mechanistic baseline and guides future efforts to identify conditions conducive to plasmon-radical coupling.</p>","PeriodicalId":20133,"journal":{"name":"Photochemistry and Photobiology","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147841718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antioxidant properties of tauroursodeoxycholic acid towards free radicals revisited.","authors":"Joanna Waresiak, Zanyar Othman Hussein, Andrzej C Żądło, Tomasz M Borowski, Tadeusz J Sarna, Anna M Pawlak","doi":"10.1111/php.70103","DOIUrl":"https://doi.org/10.1111/php.70103","url":null,"abstract":"<p><p>Antioxidant properties of tauroursodeoxycholic acid (TUDCA), a cytoprotective bile acid, toward free radicals-induced oxidation of lipids were studied in different model systems using EPR oximetry, EPR spin trapping and the FOX-2 method. Various generators of free radicals were tested: Victoria Blue as a type I sensitizer with minimal generation of singlet oxygen (Φ_Δ ≈ 0.2%), hydrophilic (Fe(III)-ADP) and hydrophobic (Fe(III)-8HQ) ferric ion complexes and thermolabile, hydrophilic azo compound (AAPH). The rate of free radicals-induced lipid peroxidation was shown to be reduced by TUDCA in the tested systems. The significant efficiency of TUDCA in retarding LOOH accumulation when lipid oxidation was induced by a hydrophobic ferric ion complex suggests that TUDCA is associated with membranes and operates most efficiently in a lipophilic environment. The efficiency of TUDCA to inhibit peroxidation of lipids induced by free radicals generated in a Fenton-type reaction suggests that the compound may chelate iron ions, thereby reducing their redox activity. Calculations performed using the DOCER algorithm support this hypothesis, indicating that the interaction energies of TUDCA with iron ions fall between those of the two reference models: 8HQ- and the ADP-iron ion complex. This confirms an intermediate interaction pattern.</p>","PeriodicalId":20133,"journal":{"name":"Photochemistry and Photobiology","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2026-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147841728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}