Bioinspired Synthesis and Physical-Chemical Properties of a New 10-Methylpyrano-4 '-hydroxyflavylium Chloride Salt

• Type: Article in International Scientific Journal
• Date: 2020

Authors

Gomes, V (Author) Other; Guimaraes, M (Author) Other; Goncalves, G (Author) Other; Victor de Freitas (Author) FCUP; Luis Cruz (Author) FCUP

Journal

Title: Synlett

Vol. 31

Pages: 334-338

ISSN: 0936-5214

Publisher: Thieme

Indexing

ISI Web of Knowledge - 9 Citations

Scopus - 9 Citations

Other information

Authenticus ID: P-00R-SS8

DOI: 10.1055/s-0039-1690744

Abstract (EN): A novel bioinspired 10-methylpyranoflavylium dye was synthesized. The dye was fully characterized by LC-DAD/ESI-MS and NMR 1D and 2D techniques, and its equilibrium constants towards pH variations were determined by UV-vis titration. These studies revealed the presence of three species (a flavylium cation AH(+) , a neutral quinoidal base A, and an anionic quinoidal base A(-)) in the pH range 1-12, driven by the two pK(a)values of the dye: pK(a1)= 6.8 +/- 0.1 and pK(a2)= 10.8 +/- 0.1. The first deprotonation of the dye occurs within the pH range for spoilage of many packed-food products, making the dye an excellent candidate for use as a pH sensor for real-time monitoring of the quality and freshness of foods.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5