Article
Oncology
Sandra Del Bino, Shosuke Ito, Juliette Sok, Kazumasa Wakamatsu
Summary: Human skin contains two distinct components: eumelanin and pheomelanin. Eumelanin consists of DHI and DHICA, while pheomelanin consists of BT and BZ. Specific degradation products can be used to quantitatively analyze these melanin monomer units. The ratio of DHI to DHICA is constant regardless of the degree of pigmentation, and the high content of DHICA may provide an antioxidant property to the epidermal melanin.
PIGMENT CELL & MELANOMA RESEARCH
(2022)
Article
Biochemistry & Molecular Biology
Martin Jarenmark, Peter Sjovall, Shosuke Ito, Kazumasa Wakamatsu, Johan Lindgren
Summary: Residual melanins have been detected in multimillion-year-old animal body fossils, but confident identification and characterization of these natural pigments remain challenging due to loss of chemical signatures during diagenesis. Experimental simulations of post-burial processes show that AHPO and ToF-SIMS are complementary in characterizing melanin traces in fossilized organismal remains.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Chemistry, Analytical
Wenzhi Zhang, Shuzhen Li, Ani Zhou, Maoguo Li
Summary: Nucleic acid detection is crucial for genetic disease diagnosis, cancer treatment, and infectious disease prevention. However, current methods based on biological amplification are complex and time-consuming. In this study, a simple and rapid nucleic acid assay using chemical cyclic amplification was developed. The Fenton-HA system, which continuously generates hydroxyl radicals via Fe3+/Fe2+ cycle, was introduced for the detection of Fe3+. The method showed good sensitivity and could be used for the detection of HIV-DNA and miRNA-21 with low limits of detection.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Physical
Fangya Li, Ying Wang, Jianyu Zhang
Summary: This study investigates the influence of ferrous ammonium sulfate concentration on the kinetic isotope effect (KIE) of a chemical demethylation system, revealing the mechanism and key steps of this process. The results suggest that the initial hydrogen extraction is the rate-limiting step, and a tight transition state structure is observed through the analysis of KIE trends.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Demin Kong, Lei Wang, Xiaoqian Chen, Wei Xia, Lingqia Su, Fangyuan Zuo, Zhengfei Yan, Sheng Chen, Jing Wu
Summary: This study proposes a new method for the degradation of polyethylene by introducing lipase and cutinase, which effectively reduces the molecular weight of polyethylene.
Article
Chemistry, Multidisciplinary
Hu Zhang, Shengnan Yue, Xiujing Zou, Xueguang Wang, Xingli Zou, Xionggang Lu
Summary: A titanium dioxide-supported chromium oxide catalyst (CrOx/TiO2) was developed for the first time to achieve complete conversion of HAIBN with a high yield of AIBN (94.8%) using hydrogen peroxide as the oxidant.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Jin Ruiming, Mu Xiaoqing, Xu Yan
Summary: In this study, the bio-chemical synthesis of DUI was achieved by coupling the biological oxidation step for the synthesis of DC from L-Dopa and the chemical reduction step for the synthesis of DUI from DC. The conversion rate of L-Dopa reached 94.75% and the yield of DUI increased to 90.03% by optimizing the reaction conditions. UPLC-Q-TOF-MS identification revealed the existence of oligomers in the reaction system.
CHEMICAL JOURNAL OF CHINESE UNIVERSITIES-CHINESE
(2022)
Article
Chemistry, Physical
Dragomir Stanisavljev, Annette Fiona Taylor, Itana Nusa Bubanja
Summary: The mechanism of the Bray-Liebhafsky (BL) reaction has been unknown for over 100 years due to the lack of experimental techniques to study all intermediates involved. A new model of the BL oscillatory reaction mechanism is constructed by considering heterogeneous processes occurring in the system. This model not only demonstrates oscillatory evolution but also explains mixing effects on the oscillatory dynamics and non-oscillatory stepwise-iodine oxidation.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Applied
Natalia Llopis, Patricia Gisbert, Alejandro Baeza
Summary: The use of HFIP solvent in the oxidative cleavage of indoles results in higher yields of 2-ketoacetanilides, and it is also suitable for oxidation of various pyrroles and furans derivatives. The sustainable and practical nature of HFIP is demonstrated by its successful recycling up to 4 cycles in larger-scale reactions.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Piao Zhu, Yinying Pu, Min Wang, Wencheng Wu, Huanlong Qin, Jianlin Shi
Summary: By reducing the concentration of GSH, the MnOOH nanocatalyst can simultaneously catalyze the autoxidation of GSH and peroxidase-like reaction to promote GSH depletion and the decomposition of H2O2, generating abundant ROS such as hydroxyl radical (center dot OH) and achieving highly effective catalytic therapeutic efficacy. The transformed endogenous antioxidant into oxidant may open a new avenue for the development of antitumor nanocatalytic medicine. Additionally, the released Mn2+ can activate the cGAS-STING pathway, promoting macrophage maturation and M1-polarization, and enhancing the innate immunotherapeutic efficacy.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Review
Chemistry, Multidisciplinary
Yudong Xue, Yunting Wang, Zhenhua Pan, Kazuhiro Sayama
Summary: This paper reviews recent developments in EC/PEC H2O2 production through water oxidation, including fundamental aspects, benchmark activity evaluation, material/catalyst selection, and strategies for increasing selectivity, efficiency, and accumulation. The challenges and outlook for water oxidation in H2O2 production are also discussed, with a focus on device-level development, accumulation and stability, and industrial applications. The review aims to inspire further research in improving EC/PEC H2O2 production.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Engineering, Industrial
Changbang Deng, Liang Jiang, Na Qin, Linmao Qian
Summary: In this study, the CMP performance of titanium alloys TA2 and TC4 was investigated under different pH and H2O2 conditions. It was found that an optimal polishing performance could be achieved at pH 4 and 0.05 wt% H2O2. The formation of a 3-4 nm oxide film after polishing was crucial for the improvement in material removal rate and surface roughness of the titanium alloys.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2021)
Article
Chemistry, Analytical
Md. Fahamidul Islam, Md. Tarikul Islam, Md. Mahmudul Hasan, Mohammed M. Rahman, Yuki Nagao, Mohammad A. Hasnat
Summary: In this study, the incorporation of Ni particles into the porous Nafion bed significantly improved the stability of the sensor for hydrogen peroxide detection. The oxidative pathway of hydrogen peroxide on the GCE/Nafion/Ni electrode was investigated, and the sensor's performance was evaluated with a linear detection limit and dynamic range.
Article
Chemistry, Organic
Cheng-yi Chen, Zhichao Lu, Thomas Scattolin, Chengsheng Chen, Yonghong Gan, Mark McLaughlin
Summary: A concise, transition-metal and protection-free synthesis of adagrasib (MRTX849), a novel KRASG12C inhibitor drug, was achieved using two sequential SNAr reactions to introduce chiral building blocks to the tetrahydropyridopyrimidine core. Extensive reaction optimization led to a robust, transition-metal-free oxidation of the sulfide intermediate. The use of a suitable leaving group at the 4-OH position facilitated a facile SNAr displacement to introduce the chiral piperazine, resulting in a five-step, chromatography-free synthesis with improved efficiency.
Review
Plant Sciences
Faisal Zulfiqar, Muhammad Nafees, Jianjun Chen, Anastasios Darras, Antonio Ferrante, John T. Hancock, Muhammad Ashraf, Abbu Zaid, Nadeem Latif, Francisco J. Corpas, Muhammad Ahsan Altaf, Kadambot H. M. Siddique
Summary: Salt stress severely limits crop productivity globally, and its effects are worsened by climate change. Plant priming, using specific chemical agents, has shown promise in enhancing plant tolerance to salt stress. This review summarizes the current knowledge on various molecules/compounds that can potentially enhance the salinity tolerance of crop plants.
FRONTIERS IN PLANT SCIENCE
(2022)
Article
Dermatology
Yoko Niki, Naoko Adachi, Masaki Fukata, Yuko Fukata, Shinichiro Oku, Chieko Makino-Okamura, Seiji Takeuchi, Kazumasa Wakamatsu, Shosuke Ito, Lieve Declercq, Daniel B. Yarosh, Tomas Mammone, Chikako Nishigori, Naoaki Saito, Takehiko Ueyama
Summary: This study found that by inhibiting the degradation of tyrosinase, the rate-limiting enzyme in melanin synthesis, an increase in melanin content and tyrosinase protein levels can be achieved in melano-genic cells. The palmitoylation site of tyrosinase was identified as Cys500, and the DHHC2, DHHC3, and DHHC15 proteins were found to be involved in tyrosinase palmitoylation. These findings suggest that palmitoylation plays an important role in regulating melanogenesis by controlling the protein levels of tyrosinase.
JOURNAL OF INVESTIGATIVE DERMATOLOGY
(2023)
Article
Clinical Neurology
Shosuke Ito, Alessandra Napolitano, Tadeusz Sarna, Kazumasa Wakamatsu
Summary: This study investigated the effects of iron and copper on the oxidation of dopamine to neuromelanin. The results showed that iron and copper not only accelerated the oxidation process, but also promoted cross-linking and degradation reactions.
JOURNAL OF NEURAL TRANSMISSION
(2023)
Article
Neurosciences
Waijiao Cai, Kazumasa Wakamatsu, Fabio A. Zucca, Qing Wang, Kai Yang, Niyaz Mohamadzadehonarvar, Pranay Srivastava, Hitomi Tanaka, Gabriel Holly, Luigi Casella, Shosuke Ito, Luigi Zecca, Xiqun Chen
Summary: By studying samples of substantia nigra from patients with Parkinson's disease, we found increased ratios of pheomelanin to dopamine in the melanin content, as well as reduced levels of eumelanins derived from both DOPA and dopamine. Additionally, an increase in pheomelanin relative to dopamine pheomelanin was observed in Parkinson's disease. These findings provide insights into the roles of pheomelanin and eumelanin in the pathophysiology of Parkinson's disease.
PROGRESS IN NEUROBIOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Yasuaki Tamura, Akira Ito, Kazumasa Wakamatsu, Toshihiko Torigoe, Hiroyuki Honda, Shosuke Ito, Kowichi Jimbow
Summary: N-Pr-4-S-CAP is selectively incorporated into melanoma cells and induces CD8(+) T cell-dependent anti-melanoma immunity, leading to the inhibition of melanoma growth. Administration of N-Pr-4-S-CAP could be a potential prophylactic therapy against local recurrence and distant metastasis of melanoma.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Biochemistry & Molecular Biology
Ana-Maria Pena, Shosuke Ito, Thomas Bornschlogl, Sebastien Brizion, Kazumasa Wakamatsu, Sandra Del Bino
Summary: To understand the impact of solar light exposure on human skin, researchers explored the chemical analysis of native and UVA-exposed melanins using non-invasive methods like multiphoton FLIM imaging and phasor and bi-exponential fitting analyses. They found that multiphoton FLIM could distinguish between different types of melanins and detect structural changes induced by UVA exposure. The study demonstrated the potential of using these techniques for characterizing mixed melanins in the skin under sunlight exposure conditions.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Review
Biochemistry & Molecular Biology
Kazumasa Wakamatsu, Shosuke Ito
Summary: Eumelanin and pheomelanin are pigments that determine the colors in animals and are produced in melanocytes in various tissues. The quantity and quality of melanin, including the ratio of eumelanin to pheomelanin, play a role in the diversity of animal colors. Methods for simultaneous measurement of eumelanin and pheomelanin have been developed to study the biochemical and genetic basis of pigmentation. The photoreactivity of melanin is also a major research focus due to its potential link to UVA-induced melanoma risk.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Review
Clinical Neurology
Toshiharu Nagatsu, Akira Nakashima, Hirohisa Watanabe, Shosuke Ito, Kazumasa Wakamatsu, Fabio A. Zucca, Luigi Zecca, Moussa Youdim, Maximilian Wulf, Peter Riederer, Johannes M. Dijkstra
Summary: The dark pigment neuromelanin (NM) is abundant in dopamine (DA) neurons in the substantia nigra (SN) and norepinephrine (NE) neurons in the locus coeruleus (LC) in the human brain. During the progression of Parkinson's disease (PD), NM levels in these neurons decrease. The synthesis pathway involves conversion of tyrosine to L-DOPA, then to DA or NE, followed by autoxidation and conversion to eumelanic or pheomelanic NM.
JOURNAL OF NEURAL TRANSMISSION
(2023)
Letter
Oncology
Thomas P. Dooley, Sydney Anderson, Shosuke Ito, Kazumasa Wakamatsu
PIGMENT CELL & MELANOMA RESEARCH
(2023)
Article
Genetics & Heredity
Huijuan Bi, Jonas Tranell, Dawn C. Harper, Weifeng Lin, Jingyi Li, Anders R. Hellstroem, Marten Larsson, Carl-Johan Rubin, Chao Wang, Shumaila Sayyab, Susanne Kerje, Bertrand Bed'hom, David Gourichon, Shosuke Ito, Kazumasa Wakamatsu, Michele Tixier-Boichard, Michael S. Marks, Daniel Globisch, Leif Andersson
Summary: This study identifies a mutation in the COMTD1 gene that causes a defect in pheomelanin pigmentation in chickens. The COMTD1 protein is found in pigment cells and may play a protective role against oxidative stress. This study provides a model for further investigation of COMTD1 function.
Article
Oncology
Yo Tanaka, Misako Sato-Matsubara, Daisuke Tsuruta, Hiroshi Tanaka, Chiho Kadono, Koji Sugawara, Norifumi Kawada, Kazumasa Wakamatsu, Shosuke Ito, Katsutoshi Yoshizato
Summary: CYGB plays a regulatory role in the melanogenic process by maintaining redox homeostasis through controlling intracellular levels of reactive oxygen species and nitric oxide.
PIGMENT CELL & MELANOMA RESEARCH
(2023)
Article
Multidisciplinary Sciences
Tiffany S. Slater, Shosuke Ito, Kazumasa Wakamatsu, Fucheng Zhang, Peter Sjovall, Martin Jarenmark, Johan Lindgren, Maria E. McNamara
Summary: The authors present a chemical taphonomy model for fossil melanins based on experimental data obtained from extant bird feathers, which predicts the composition of fossil melanins and provides evidence for the molecular preservation of phaeomelanin in 10 million year old frogs.
NATURE COMMUNICATIONS
(2023)