Bulletin of the Korean Chemical Society最新文献

{"title":"Identification of methylated cytidines using terahertz spectroscopy","authors":"Janghee Hong,&nbsp;Rakwoo Chang","doi":"10.1002/bkcs.70168","DOIUrl":"https://doi.org/10.1002/bkcs.70168","url":null,"abstract":"<p>The potential role of terahertz (THz) spectroscopy in identifying and manipulating DNA methylation, a key cancer biomarker, is currently being debated. This study investigates the THz spectra of both methylated and demethylated cytidines to resolve this issue using quantum calculations. Our findings confirm that the methylation of cytidines can be identified by the spectral features in the THz region, which we attribute to the rotational motion of the methyl group. This result validates THz spectroscopy as a potential diagnostic tool for the early stage of cancer. However, the calculated bond dissociation energy for the demethylation C-C bond is approximately 106.5 kcal/mol, which corresponds to several orders of magnitude higher than the energy of a single THz photon, making direct demethylation via a single-photon process energetically unfeasible. Hence, we conclude that while THz spectroscopy is a promising tool for identifying the methylation of DNA, its proposed therapeutic application for inducing the demethylation of the 5-methylcytidines is unlikely.</p>","PeriodicalId":54252,"journal":{"name":"Bulletin of the Korean Chemical Society","volume":"47 6","pages":"711-715"},"PeriodicalIF":2.2,"publicationDate":"2026-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148203076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dried blood spot analysis in antidoping: Technical challenges, analytical advances, and future perspectives","authors":"Jihyun Yoon,&nbsp;Jiyeong Hong,&nbsp;Hanbin Oh,&nbsp;Chi Hwan Lee,&nbsp;Ki Hun Kim","doi":"10.1002/bkcs.70167","DOIUrl":"https://doi.org/10.1002/bkcs.70167","url":null,"abstract":"<p>Dried blood spot (DBS) analysis is a sample collection strategy that requires minimal volume of blood while providing practical advantages such as a simple collection procedure, enhanced sample stability, and efficient transport and storage. Due to these benefits, DBS has been applied in newborn screening, therapeutic drug monitoring, and pharmacokinetic studies for clinical and life sciences. Recently, the potential of DBS has gained attention for antidoping; therefore, the World Anti-Doping Agency (WADA) has advanced the introduction and application of DBS-based analytical approaches as a complementary strategy to conventional urine and venous blood samples. Consequently, various studies have been conducted for the development of high-sensitivity analytical methods for prohibited substances, evaluation of DBS sampling devices, and the advancement of sample preparation focused on overcoming matrix-related challenges. The development of DBS analysis and its clinical applications are overviewed, followed by a discussion of the rationale for its adoption in antidoping analysis and WADA's strategy. The challenges in DBS sampling and instrumental analysis were also investigated comprehensively, and recent advances in addressing limitations were also investigated. The analysis of steroid esters and other methods for substances in WADA technical documents was mainly focused on, and emerging approaches for erythropoietin and its markers in blood doping. Perspectives for the DBS analysis in antidoping operation in the large sports events were discussed.</p>","PeriodicalId":54252,"journal":{"name":"Bulletin of the Korean Chemical Society","volume":"47 6","pages":"674-688"},"PeriodicalIF":2.2,"publicationDate":"2026-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/bkcs.70167","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148203089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polarization anisotropy identifies bound azide in photoexcited ferric myoglobin: Resolving photodeligation ambiguity by femtosecond infrared spectroscopy","authors":"Seongchul Park,&nbsp;Juhyang Shin,&nbsp;Manho Lim","doi":"10.1002/bkcs.70176","DOIUrl":"https://doi.org/10.1002/bkcs.70176","url":null,"abstract":"<p>Polarization-resolved femtosecond time-resolved infrared spectroscopy was employed to elucidate the origin of a transient absorption band in azide-bound ferric myoglobin (MbN₃) following Q-band excitation. Previous studies attributed this feature to a low-spin to high-spin transition during electronic relaxation of the photoexcited MbN₃, but ambiguity remained regarding possible photodissociation. By analyzing polarization anisotropy, we directly determined the orientation of the azide ligand associated with the transient signal. The anisotropy of the new absorption band is identical to that of the bound state, yielding an angle of 53° ± 1° relative to the heme normal, consistent with a bound configuration. This result rules out photodissociation, which would produce markedly different anisotropy. The transient spectral evolution is therefore attributed to a spin-state transition within the bound state following photoexcitation. These findings demonstrate that MbN₃ does not undergo photodeligation under visible Q-band excitation and provide clear mechanistic insight into the photophysics of anion-bound ferric heme proteins.</p>","PeriodicalId":54252,"journal":{"name":"Bulletin of the Korean Chemical Society","volume":"47 6","pages":"720-723"},"PeriodicalIF":2.2,"publicationDate":"2026-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/bkcs.70176","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148202949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Serotonin 5-HT7 receptor signaling in neuropsychiatric disorders","authors":"Eunseo Park,&nbsp;Hyunah Choo","doi":"10.1002/bkcs.70172","DOIUrl":"https://doi.org/10.1002/bkcs.70172","url":null,"abstract":"<p>Serotonin 7 receptor (5-HT₇R) has emerged as a multifunctional G protein-coupled receptor that regulates neuronal excitability, structural plasticity, and circuit function across the central nervous system. Beyond canonical Gs-dependent signaling, accumulating evidence indicates that 5-HT₇R also engages G12-associated Rho GTPase pathways and <i>β</i>-arrestin/SRC family kinase-mediated signaling, thereby enabling diverse and context-dependent regulation of intracellular effectors involved in cytoskeletal remodeling, translational control, and sustained kinase activation. In this review, we summarize three representative 5-HT₇R signaling axes and discuss how these pathways may differentially contribute to the pathophysiology of major neuropsychiatric disorders, with a particular focus on autism spectrum disorder, depression, and schizophrenia. Across these disorders, 5-HT₇R-linked signaling is associated with developmental wiring, synaptic maturation, stress-responsive plasticity, glutamatergic dysfunction, and cognitive circuit regulation. Importantly, the functional consequences of 5-HT₇R activation appear to depend on developmental stage, brain region, cell type, ligand condition, and subcellular signaling context, indicating that similar downstream readouts may carry distinct mechanistic meanings. By adopting a pathway–disease mapping perspective, this review highlights 5-HT₇R as a versatile molecular interface connecting serotonergic signaling to disease-relevant neural plasticity and suggests that future therapeutic strategies may benefit from pathway-informed modulation rather than a simple agonist–antagonist framework.</p>","PeriodicalId":54252,"journal":{"name":"Bulletin of the Korean Chemical Society","volume":"47 6","pages":"698-710"},"PeriodicalIF":2.2,"publicationDate":"2026-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/bkcs.70172","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148202970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bio-inspired melatonin-naphthalimide conjugate as a biocompatible fluorescent probe for real-time H2S imaging in living cells","authors":"Maxine Mambo Fortibui,&nbsp;Hui Joo Kim,&nbsp;Minju Kang,&nbsp;Min Hee Lee","doi":"10.1002/bkcs.70174","DOIUrl":"https://doi.org/10.1002/bkcs.70174","url":null,"abstract":"<p>We report probe <b>1</b>, a novel melatonin–naphthalimide-based fluorescent probe for the rapid and sensitive detection of hydrogen sulfide (H₂S). The probe exhibits a distinct “turn-on” fluorescence response through the specific reduction of an azide group to an amine, a mechanism rigorously validated by spectroscopic analysis, LC/MS, and TD-DFT calculations. Probe <b>1</b> displays high sensitivity with a detection limit of 0.19 μM and excellent selectivity over other relevant analytes. Furthermore, bio-imaging in A549 cells confirmed its low cytotoxicity and efficient membrane permeability, enabling real-time monitoring of intracellular H₂S fluctuations. These results demonstrate the potential of <b>1</b> as a robust and biocompatible tool for H₂S detection in both environmental and biological contexts.</p>","PeriodicalId":54252,"journal":{"name":"Bulletin of the Korean Chemical Society","volume":"47 6","pages":"716-719"},"PeriodicalIF":2.2,"publicationDate":"2026-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148203001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature-dependent thermodynamic and kinetic analysis of ketohexose tautomerism by quantitative 1H NMR: A comparative study of D-fructose and D-allulose","authors":"Hyojin Cho,&nbsp;Jinyoung Kim,&nbsp;Yeon Ju Shin,&nbsp;Hyo-Yeon Yu,&nbsp;Sangdoo Ahn","doi":"10.1002/bkcs.70170","DOIUrl":"https://doi.org/10.1002/bkcs.70170","url":null,"abstract":"<p>A quantitative thermodynamic and kinetic investigation of ketohexose tautomerism was performed using temperature-resolved ¹H quantitative nuclear magnetic resonance (qNMR) spectroscopy. The tautomeric equilibria and mutarotation kinetics of D-fructose and its C3 epimer, D-allulose, were systematically examined in aqueous solution. Complete ¹H and ¹³C resonance assignments enabled reliable quantification of all detectable cyclic and acyclic species, including minor open-chain forms. Temperature-dependent equilibrium analysis revealed fundamentally distinct thermodynamic landscapes: D-fructose was strongly biased toward β-pyranose, whereas D-allulose preferentially populated furanose forms, particularly α-furanose. Increasing the temperature shifted both systems toward furanose and keto species, consistent with entropically favored populations of less conformationally constrained structures. Independent ¹³C NMR measurements confirmed the quantitative reliability of the ¹H qNMR approach. Time-resolved in situ ¹H NMR measurements enabled the determination of apparent ring-opening rate constants using a reversible first-order kinetic framework. Activation parameters derived from Arrhenius and Eyring analyses revealed that the most thermally responsive pathways differ between the epimers: D-fructose exhibited activation energies of 59–64 kJ·mol⁻¹ for furanose ring opening, whereas D-allulose showed substantially higher barriers of 77–83 kJ·mol⁻¹ for pyranose ring-opening processes. These findings demonstrate that minimal stereochemical variation reorganizes not only equilibrium distributions but also pathway-specific kinetic responses in ketohexose tautomerism. The study establishes temperature-dependent quantitative ¹H NMR as an efficient platform for simultaneous equilibrium and pathway-resolved kinetic characterization of carbohydrate systems.</p>","PeriodicalId":54252,"journal":{"name":"Bulletin of the Korean Chemical Society","volume":"47 6","pages":"736-744"},"PeriodicalIF":2.2,"publicationDate":"2026-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148202971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving predictive performance for molecular ADMET properties using a chemical language model","authors":"Jong Hyeon Lim,&nbsp;Myounwoo Kim,&nbsp;Youngmahn Han,&nbsp;Jin Yong Lee","doi":"10.1002/bkcs.70177","DOIUrl":"https://doi.org/10.1002/bkcs.70177","url":null,"abstract":"<p>Molecular encoders play a central role in AI-driven drug design by defining the chemical representations used for downstream prediction and decision-making. However, many widely used encoders are not explicitly trained to internalize ADMET-relevant structure–property relationships across diverse endpoints. In this study, we fine-tuned a DeBERTa-based SMILES (Simplified Molecular Input Line Entry System) encoder to internalize ADMET-relevant structure–property information across 22 endpoints under a multi-task learning (MTL) framework, while maintaining strong comprehension of SMILES syntax and structural regularities. Starting from a pretrained ZINC-based DeBERTa checkpoint, we trained on a 300 K PubChem–ADMET dataset using a multi-output regression scheme with a Focal MAE objective to mitigate optimization imbalance across heterogeneous endpoints. To consistently assess balanced performance across tasks with heterogeneous metrics, we further introduced the ADMET-Balanced Performance Score (ABPS) as an integrated evaluation criterion. On the TDC benchmark leaderboard, our encoder achieved state-of-the-art performance on 12 endpoints and top-5 performance on 7 endpoints, indicating broad competitiveness across ADMET tasks. In addition, by restoring an MLM head and tracking MLM accuracy throughout fine-tuning, we show that DeBERTa preserves SMILES token-level syntax competence more stably than BERT- and RoBERTa-based encoders under the same ADMET training conditions. Overall, this work establishes an ADMET-aware SMILES encoder that balances broad-spectrum endpoint learning with preservation of pretrained SMILES knowledge, and can serve as a foundation for downstream molecular modeling pipelines, including future multimodal drug-design systems.</p>","PeriodicalId":54252,"journal":{"name":"Bulletin of the Korean Chemical Society","volume":"47 6","pages":"756-768"},"PeriodicalIF":2.2,"publicationDate":"2026-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148203067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cover Picture: Bio-inspired Melatonin-Naphthalimide Conjugate as a Biocompatible Fluorescent Probe for Real-time H2S Imaging in Living Cells (BKCS 6/2026) by Maxine Mambo Fortibui, Hui Joo Kim, Minju Kang, and Min Hee Lee","authors":"","doi":"10.1002/bkcs.70150","DOIUrl":"https://doi.org/10.1002/bkcs.70150","url":null,"abstract":"<p>The cover image illustrates a bio-inspired fluorescent probe designed for the rapid and selective detection of hydrogen sulfide (H₂S). By integrating a melatonin moiety into a naphthalimide framework, this probe effectively monitors real-time H₂S fluctuations in living A549 cells. Featuring excellent biocompatibility and cell permeability, it offers powerful potential for cancer-related bio-imaging. Details are in the article by Maxine Mambo Fortibui, Hui Joo Kim, Minju Kang, and Min Hee Lee.\u0000\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure></p>","PeriodicalId":54252,"journal":{"name":"Bulletin of the Korean Chemical Society","volume":"47 6","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/bkcs.70150","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148203057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"","authors":"","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":54252,"journal":{"name":"Bulletin of the Korean Chemical Society","volume":"47 5","pages":"502-503"},"PeriodicalIF":2.2,"publicationDate":"2026-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148090607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"","authors":"","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":54252,"journal":{"name":"Bulletin of the Korean Chemical Society","volume":"47 5","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148090606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}