{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T18:47:13Z","timestamp":1788893233094,"version":"build-2803163510"},"reference-count":42,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2016,12,3]],"date-time":"2016-12-03T00:00:00Z","timestamp":1480723200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Xanthines represent a wide class of compounds closely related to the DNA bases adenine and guanine. Ubiquitous in the human body, they are capable of replacing natural bases in double helices and give rise to four-stranded structures. Although the use of their fluorescence for analytical purposes was proposed, their fluorescence properties have not been properly characterized so far. The present paper reports the first fluorescence study of xanthine solutions relying on femtosecond spectroscopy. Initially, we focus on 3-methylxanthine, showing that this compound exhibits non-exponential fluorescence decays with no significant dependence on the emission wavelength. The fluorescence quantum yield (3 \u00d7 10\u22124) and average decay time (0.9 ps) are slightly larger than those found for the DNA bases. Subsequently, we compare the dynamical fluorescence properties of seven mono-, di- and tri-methylated derivatives. Both the fluorescence decays and fluorescence anisotropies vary only weakly with the site and the degree of methylation. These findings are in line with theoretical predictions suggesting the involvement of several conical intersections in the relaxation of the lowest singlet excited state.<\/jats:p>","DOI":"10.3390\/molecules21121668","type":"journal-article","created":{"date-parts":[[2016,12,5]],"date-time":"2016-12-05T10:27:09Z","timestamp":1480933629000},"page":"1668","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Xanthines Studied via Femtosecond Fluorescence Spectroscopy"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5874-6249","authenticated-orcid":false,"given":"Pascale","family":"Changenet-Barret","sequence":"first","affiliation":[{"name":"LIDYL, CEA, CNRS, Universit\u00e9 Paris-Saclay, F-91191 Gif-sur-Yvette, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0331-3980","authenticated-orcid":false,"given":"Lajos","family":"Kov\u00e1cs","sequence":"additional","affiliation":[{"name":"Department of Medicinal Chemistry, University of Szeged, D\u00f3m t\u00e9r 8, 6720 Szeged, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dimitra","family":"Markovitsi","sequence":"additional","affiliation":[{"name":"LIDYL, CEA, CNRS, Universit\u00e9 Paris-Saclay, F-91191 Gif-sur-Yvette, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thomas","family":"Gustavsson","sequence":"additional","affiliation":[{"name":"LIDYL, CEA, CNRS, Universit\u00e9 Paris-Saclay, F-91191 Gif-sur-Yvette, France"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2016,12,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"8135","DOI":"10.1093\/nar\/14.20.8135","article-title":"Synthesis and properties of oligonucleotides containing 2\u2032-deoxynebularine and 2\u2032-deoxyxanthosine","volume":"14","author":"Eritja","year":"1986","journal-title":"Nucleic Acids Res."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"476","DOI":"10.1039\/C0NJ00612B","article-title":"3-substituted xanthines as promising candidates for quadruplex formation: Computational, synthetic and analytical studies","volume":"35","author":"Paragi","year":"2011","journal-title":"New J. 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