{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,28]],"date-time":"2026-03-28T01:28:56Z","timestamp":1774661336127,"version":"3.50.1"},"reference-count":18,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2016,10,20]],"date-time":"2016-10-20T00:00:00Z","timestamp":1476921600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>3-Deoxyanthocyanidins and their O-\u03b2-d-glucosides are natural pigments abundant in black sorghum. O-glycosidation can perturb the acid-base properties of the chromophore and lower its electron density with a large impact on the distribution of colored and colorless forms in aqueous solution. In this work, the influence of O-glycosidation on color is systematically studied from a series of 3-deoxyanthocyanin analogs. The pH- and light-dependent reversible reactions of 7-\u03b2-d-glucopyranosyloxy-4\u2032-hydroxyflavylium (P3) and 4\u2032-\u03b2-d-glucopyranosyloxy-7-hydroxyflavylium (P5) were completely characterized in mildly acidic solution and compared with the parent aglycone 4\u2032,7-dihydroxyflavylium ion and the O-methylethers of P3 and P5. Except P5, the chalcone forms of the pigments exhibit a high cis-trans isomerization barrier that allows a pseudo-equilibrium involving all species except the trans-chalcone. At equilibrium, only the flavylium cation and trans-chalcone are observed. With all pigments, the colored flavylium ion can be generated by irradiation of the trans-chalcone (photochromism). Glycosidation of C7\u2013OH accelerates hydration and strongly slows down cis-trans isomerization with the pH dependence of the apparent isomerization rate constant shifting from a bell-shaped curve to a sigmoid. The color of P5 is much more stable than that of its regioisomer P3 in near-neutral conditions.<\/jats:p>","DOI":"10.3390\/ijms17101751","type":"journal-article","created":{"date-parts":[[2016,10,20]],"date-time":"2016-10-20T10:15:49Z","timestamp":1476958549000},"page":"1751","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Analogs of Natural 3-Deoxyanthocyanins: O-Glucosides of the 4\u2032,7-Dihydroxyflavylium Ion and the Deep Influence of Glycosidation on Color"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0121-3695","authenticated-orcid":false,"given":"Nuno","family":"Bas\u00edlio","sequence":"first","affiliation":[{"name":"LAQV-REQUIMTE, Department of Chemistry, Faculty of Science &amp; Technology, Universidade NOVA de Lisboa, 2829-516 Monte de Caparica, Portugal"}]},{"given":"Sheiraz","family":"Al Bittar","sequence":"additional","affiliation":[{"name":"Faculty of Sciences, Technology &amp; Health, University of Avignon, INRA, UMR408, 84000 Avignon, France"}]},{"given":"Nathalie","family":"Mora","sequence":"additional","affiliation":[{"name":"Faculty of Sciences, Technology &amp; Health, University of Avignon, INRA, UMR408, 84000 Avignon, France"}]},{"given":"Olivier","family":"Dangles","sequence":"additional","affiliation":[{"name":"Faculty of Sciences, Technology &amp; Health, University of Avignon, INRA, UMR408, 84000 Avignon, France"}]},{"given":"Fernando","family":"Pina","sequence":"additional","affiliation":[{"name":"LAQV-REQUIMTE, Department of Chemistry, Faculty of Science &amp; Technology, Universidade NOVA de Lisboa, 2829-516 Monte de Caparica, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2016,10,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1178","DOI":"10.1021\/jf103963t","article-title":"Uncommonly high levels of 3-deoxyanthocyanidins and antioxidant capacity in the leaf sheaths of dye sorghum","volume":"59","author":"Nout","year":"2011","journal-title":"J. Agric. Food Chem."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1515\/znc-2001-3-402","article-title":"A novel acetylated 3-deoxyanthocyanidin laminaribioside from the fern Blechnum novae-zelandiae","volume":"56","author":"Swinny","year":"2001","journal-title":"Z. Naturforsch. C"},{"key":"ref_3","first-page":"61","article-title":"Luteolinidin 5-O-glucoside from Azolla as a stable taxonomic marker","volume":"36","author":"Iwashina","year":"2010","journal-title":"Bull. Natl. Mus. Nat. Sci. Ser. B"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1016\/j.supflu.2013.12.008","article-title":"Extraction of anthocyanins and luteolin from Arrabidaea chica by sequential extraction in fixed bed using supercritical CO2, ethanol and water as solvents","volume":"86","author":"Paula","year":"2014","journal-title":"J. Supercrit. Fluids"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1016\/j.jcs.2013.10.009","article-title":"Increasing the utilisation of sorghum, millets and pseudocereals: Developments in the science of their phenolic phytochemicals, biofortification and protein functionality","volume":"59","author":"Taylor","year":"2014","journal-title":"J. Cereal Sci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"246","DOI":"10.1016\/j.foodchem.2014.03.105","article-title":"Thermal stability of 3-deoxyanthocyanidin pigments","volume":"160","author":"Yang","year":"2014","journal-title":"Food Chem."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"869","DOI":"10.1039\/C1CS15126F","article-title":"Chemistry and applications of flavylium compounds: A handful of colours","volume":"41","author":"Pina","year":"2012","journal-title":"Chem. Soc. Rev."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"6885","DOI":"10.1021\/jf404869m","article-title":"Chemical applications of anthocyanins and related compounds. A source of bioinspiration","volume":"62","author":"Pina","year":"2014","journal-title":"J. Agric. Food Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"4496","DOI":"10.1021\/ja000190d","article-title":"Artificial chemical systems capable of mimicking some elementary properties of neurons","volume":"122","author":"Pina","year":"2000","journal-title":"J. Am. Chem. Soc."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1359","DOI":"10.1021\/ja00447a012","article-title":"Mechanism of the structural transformations of anthocyanins in acidic media","volume":"99","author":"Brouillard","year":"1977","journal-title":"J. Am. Chem. Soc."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2749","DOI":"10.1021\/jp511351w","article-title":"Excited-state proton transfer in confined medium. 4-Methyl-7-hydroxyflavylium and \u03b2-naphthol incorporated in cucurbit [7] uril","volume":"119","author":"Laia","year":"2015","journal-title":"J. Phys. Chem. B."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3107","DOI":"10.1016\/j.tet.2014.09.051","article-title":"Anthocyanins and derivatives are more than flavylium cations","volume":"71","author":"Pina","year":"2015","journal-title":"Tetrahedron"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"3166","DOI":"10.1039\/c3nj00588g","article-title":"Effect of \u03b2-cyclodextrin on the chemistry of 3\u2032,4\u2032,7-trihydroxyflavylium","volume":"37","author":"Fernandes","year":"2013","journal-title":"New J. Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"4167","DOI":"10.1021\/jp402761j","article-title":"Impact of water on the cis-trans photoisomerization of hydroxychalcones","volume":"117","author":"Leydet","year":"2013","journal-title":"J. Phys. Chem."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"308","DOI":"10.1016\/j.dyepig.2013.10.033","article-title":"Anthocyanins and related compounds. Detecting the change of regime between rate control by hydration or by tautomerization","volume":"102","author":"Pina","year":"2014","journal-title":"Dyes Pigment."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"4294","DOI":"10.1016\/j.tet.2016.05.076","article-title":"A simple synthesis of 3-deoxyanthocyanidins and their O-glucosides","volume":"72","author":"Mora","year":"2016","journal-title":"Tetrahedron"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1314","DOI":"10.1021\/ed074p1314","article-title":"An easy and cheap flash spectroscopy experiment","volume":"74","author":"Maestri","year":"1997","journal-title":"J. Chem. Educ."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"518","DOI":"10.1098\/rspa.1956.0102","article-title":"A new sensitive chemical actinometer. II. Potassium ferrioxalate as a standard chemical actinometer","volume":"235","author":"Hatchard","year":"1956","journal-title":"Proc. R. Soc. Lond. Ser. 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