{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,13]],"date-time":"2026-05-13T22:29:54Z","timestamp":1778711394185,"version":"3.51.4"},"reference-count":25,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2019,5,2]],"date-time":"2019-05-02T00:00:00Z","timestamp":1556755200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Konica Minolta Imaging Science Encouragement Award","award":["No number"],"award-info":[{"award-number":["No number"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>A small extent of endogenous labile zinc is involved in many vital physiological roles in living systems. However, its detailed functions have not been fully elucidated. In this study, we developed a novel biheteroaryl-based low molecular weight fluorescent sensor, 3-(phenylsulfonyl)-pyrazine\u2013pyridone (5b), and applied it for the detection of endogenous labile zinc ions from lung cancer cells during apoptosis. The electron-withdrawing property of the sulfonyl group between the phenyl ring as an electron donor and the pyridone ring as a fluorophore inhibited the intramolecular charge transfer state, and the background fluorescence of the sensor was decreased in aqueous media. From the structure\u2013fluorescence relationship analysis of the substituent effects with\/without Zn2+, compound 5b acting as a sensor possessed favorable properties, including a longer emission wavelength, a large Stokes shift (over 100 nm), a large fluorescence enhancement in response to Zn2+ under physical conditions, and good cell membrane permeability in living cells. Fluorescence imaging studies of human lung adenocarcinoma cells (A549) undergoing apoptosis revealed that compound 5b could detect endogenous labile zinc ions. These experiments suggested that the low molecular weight compound 5b is a potential fluorescence sensor for Zn2+ toward understanding its functions in living systems.<\/jats:p>","DOI":"10.3390\/s19092049","type":"journal-article","created":{"date-parts":[[2019,5,7]],"date-time":"2019-05-07T03:15:46Z","timestamp":1557198946000},"page":"2049","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Synthesis of a Novel Pyrazine\u2013Pyridone Biheteroaryl-Based Fluorescence Sensor and Detection of Endogenous Labile Zinc Ions in Lung Cancer Cells"],"prefix":"10.3390","volume":"19","author":[{"given":"Masayori","family":"Hagimori","sequence":"first","affiliation":[{"name":"Department of Biophysical Chemistry, Kobe Pharmaceutical University, 4-19-1 Motoyamakita Machi, Higashinada Ku, Kobe 658-8558, Japan"},{"name":"Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mana","family":"Taniura","sequence":"additional","affiliation":[{"name":"Department of Biophysical Chemistry, Kobe Pharmaceutical University, 4-19-1 Motoyamakita Machi, Higashinada Ku, Kobe 658-8558, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Naoko","family":"Mizuyama","sequence":"additional","affiliation":[{"name":"Clinical Research Center, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yasushi","family":"Karimine","sequence":"additional","affiliation":[{"name":"Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shigeru","family":"Kawakami","sequence":"additional","affiliation":[{"name":"Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hideo","family":"Saji","sequence":"additional","affiliation":[{"name":"Graduate School of Pharmaceutical Sciences, Kyoto University, 46\u201329 Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Takahiro","family":"Mukai","sequence":"additional","affiliation":[{"name":"Department of Biophysical Chemistry, Kobe Pharmaceutical University, 4-19-1 Motoyamakita Machi, Higashinada Ku, Kobe 658-8558, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,5,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"209","DOI":"10.1007\/978-94-011-0255-1_17","article-title":"The role of metal ions in biological systems and medicine","volume":"459","author":"Anastassopoulou","year":"1995","journal-title":"Bioinorg. 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