A mechanistic investigation of H/D scrambling processes in flavonoids

Abstract

Several classes of flavonoids, such as anthocyanins, flavonols, flavanols and flavones, undergo a slow H/D exchange on aromatic ring A, leading to full deuteration at positions C(6) and C(8). Within the flavanol class, H-C(6) and H-C(8) of catechin and epicatechin are slowly exchanged in D2O to the corresponding deuterated analogues; even quercetin, a relevant flavonol representative, shows the same behaviour in a D2O/DMSOd6 1:1 solution. Detailed kinetic measurements of these H/D scrambling processes are here reported by exploiting the time-dependent changes of their peak areas in the 1H-NMR spectra taken at different temperatures. A unifying reaction mechanism is also proposed based on our detailed kinetic observations, even taking into account pH and solvent effects. Molecular modelling and QM calculations were also carried out to shed more light on several molecular details of the proposed mechanism.

DOI:

Publication date: September 16, 2021

Issue: Macrowine 2021

Type: Article

Authors

Graziano Guella

Biorganic Chemistry Lab/Dept. of Physics/University of Trento,Federico Bonaldo1, Fulvio Mattivi2, Daniele Catorci*, &, Panagiotis Arapitsas3, Graziano Guella1, * 1  Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, Trento, Italy; 2 Department of Cellular, Computational and Integrative Biology – CIBIO and C3A, University of Trento, Trento, Italy; 3 Department of Food Quality and Nutrition, Research and Innovation Centre, Fondazione Edmund Mach (FEM), San Michele all’Adige, Italy; * D. Catorci passed away on June 27th, 2020

Contact the author

Keywords

flavonoids; chemistry of polyphenols; h/d isotopic scrambling; reaction mechanism

Citation

Related articles…

Aroma chemical markers of Durello wines from different vintages and origins: a case study

Wines expressing sensory characters that are representative of their varietal and geographical origins are highly sought after in today’s market. It is therefore of considerable technological interest to investigate the aromatic aspects of specific wines and to identify the odorous substances involved. This study investigated aroma chemical and sensory diversity of Durello DOC white

Bees, climate changes, and “environmental sustainability 4.1c” in viticulture and the territory for a new global multiproductive “biometaethical district 4.1c”

The use of bees as pollinators in vine varieties with physiologically female flowers (Picolit, Bicane, Ceresa, Moscato rosa, etc.) (Cargnello, 1983) and as bio-indicators for biodiversity and environmental sustainability is well-known. Furthermore, there are interests in: 1-a. Making the viticulture of Belluno (Province of Veneto in North-eastern Italy, which is also famous for the Dolomites -a UNESCO World Heritage-) regain the socioeconomic role which it is entitled to and which it had got in its past by aiming at the enhancement of local grape variety in harmony with others, for example with the neighboring area of the Conegliano and Valdobbiadene Prosecco Superiore DOCG; 2-a. Maintaining and further improving the important natural and healthy environment of Belluno, and making its territory and the “lookout” means of the environmental sustainability, including its vineyards, even more naturally original and sustainable 4.1C.

The effect of management practices and landscape context on vineyard biodiversity

Intensification is considered one of the major drivers of biodiversity loss in farmland. The more intensive management practices that have been adopted the last decades, contributed to species declines from all taxonomic groups. Moreover, agricultural intensification has led to an important change of land use. Complex, mixed agro-ecosystems with cultivated and non-cultivated habitats have been converted to simplified, intensive and homogeneous ones with severe effects on biodiversity.

Comparison of the skin resistance of several grape varieties in relation to their physico-chemical properties

The purpose of this study is to compare the skin resistance (SR) of the grapes with physico-chemical propertiess using a stong dataset and multidimentional statistical analysis .
A recent study has shown the role skin resistance plays against pest invasion but skin resistance could be a useful agronomic parameter, for example in the choice of the type of winemaking, by influencing the quantity of juice during crushing and maceration.

NAVIC–20 years of a lean management model for wine business R&D

Considering That Innovation Supports A Company’s Competitive Advantage And Drive Higher Profits (Dogru A. & Peyrette J., 2022), A Key Challenge Of Wine Companies Is Getting Practitioners To Understand That Innovation-Related Wine Research Increases The Likelihood Of Competitive Advantage, Bringing Financial Success. A Continued And Enhanced Investment In Research Is, Thus, A Prerequisite For Commercial Success In Today’s Globalized And Competitive Wine Industry (Høj P., Pretorius I.S., & Day R., 2003).