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The creation and physiological relevance of divergent hydroxylation patterns in the flavonoid pathway.

Halbwirth H - Int J Mol Sci (2010)

Bottom Line: The large number of divergent chalcones and flavonoid structures is from the extensive modification of the basic molecules.The hydroxylation pattern influences physiological properties such as light absorption and antioxidative activity, which is the base for many beneficial health effects of flavonoids.In some cases antiinfective properties are also effected.

View Article: PubMed Central - PubMed

Affiliation: Institut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften, Technische Universität Wien, Austria. hhalb@mail.zserv.tuwien.ac.at

ABSTRACT
Flavonoids and biochemically-related chalcones are important secondary metabolites, which are ubiquitously present in plants and therefore also in human food. They fulfill a broad range of physiological functions in planta and there are numerous reports about their physiological relevance for humans. Flavonoids have in common a basic C(6)-C(3)-C(6) skeleton structure consisting of two aromatic rings (A and B) and a heterocyclic ring (C) containing one oxygen atom, whereas chalcones, as the intermediates in the formation of flavonoids, have not yet established the heterocyclic C-ring. Flavonoids are grouped into eight different classes, according to the oxidative status of the C-ring. The large number of divergent chalcones and flavonoid structures is from the extensive modification of the basic molecules. The hydroxylation pattern influences physiological properties such as light absorption and antioxidative activity, which is the base for many beneficial health effects of flavonoids. In some cases antiinfective properties are also effected.

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Part of the absorption spectra of anthocyanidins (a–f) with divergent hydroxylation patterns. With the exception of pelargonidin (a) and robinetinidin (f), structures of cyanidin (b), delphinidin (c), luteolinidin (d) and apigeninidin (e) are only partially shown.
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f11-ijms-11-00595: Part of the absorption spectra of anthocyanidins (a–f) with divergent hydroxylation patterns. With the exception of pelargonidin (a) and robinetinidin (f), structures of cyanidin (b), delphinidin (c), luteolinidin (d) and apigeninidin (e) are only partially shown.

Mentions: The UV-VIS spectrum of flavonoids typically shows a band at 210–290 nm region (band I), which is due to the absorption of the benzoyl system (A-ring), and a second band in the 300–400 nm region (band II), which is associated with the cinnamoyl system (rings B and C) [117] (Figure 10). With increasing conjugation the absorbance shifts towards higher wavelengths, therefore, chalcones, aurones and anthocyanidins have maximal absorbance in the visible part of the spectrum. In the case of anthocyanidins, band II shows its maximum around 520 nm. For many pollinating insects absorption in the UV (band I) is also relevant for colour perception because their specific colour sense makes them blind to scarlet red coloration but sensitive to the UV-range of the spectrum [118–123]. The number and type of substituents affiliated to the basic flavonoid structure has an impact on light absorbance. Additional hydroxyl groups shift the absorption maxima. The hydroxyl group in position 3 of ring C has a higher impact on the absorption maximum of band II than hydroxyl groups in rings A and B. For anthocyanidins (compare a with e and b with d in Figure 11), this results in a colour shift of 3-deoxyanthocyanidins into the yellow region (Figure 12).


The creation and physiological relevance of divergent hydroxylation patterns in the flavonoid pathway.

Halbwirth H - Int J Mol Sci (2010)

Part of the absorption spectra of anthocyanidins (a–f) with divergent hydroxylation patterns. With the exception of pelargonidin (a) and robinetinidin (f), structures of cyanidin (b), delphinidin (c), luteolinidin (d) and apigeninidin (e) are only partially shown.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2852856&req=5

f11-ijms-11-00595: Part of the absorption spectra of anthocyanidins (a–f) with divergent hydroxylation patterns. With the exception of pelargonidin (a) and robinetinidin (f), structures of cyanidin (b), delphinidin (c), luteolinidin (d) and apigeninidin (e) are only partially shown.
Mentions: The UV-VIS spectrum of flavonoids typically shows a band at 210–290 nm region (band I), which is due to the absorption of the benzoyl system (A-ring), and a second band in the 300–400 nm region (band II), which is associated with the cinnamoyl system (rings B and C) [117] (Figure 10). With increasing conjugation the absorbance shifts towards higher wavelengths, therefore, chalcones, aurones and anthocyanidins have maximal absorbance in the visible part of the spectrum. In the case of anthocyanidins, band II shows its maximum around 520 nm. For many pollinating insects absorption in the UV (band I) is also relevant for colour perception because their specific colour sense makes them blind to scarlet red coloration but sensitive to the UV-range of the spectrum [118–123]. The number and type of substituents affiliated to the basic flavonoid structure has an impact on light absorbance. Additional hydroxyl groups shift the absorption maxima. The hydroxyl group in position 3 of ring C has a higher impact on the absorption maximum of band II than hydroxyl groups in rings A and B. For anthocyanidins (compare a with e and b with d in Figure 11), this results in a colour shift of 3-deoxyanthocyanidins into the yellow region (Figure 12).

Bottom Line: The large number of divergent chalcones and flavonoid structures is from the extensive modification of the basic molecules.The hydroxylation pattern influences physiological properties such as light absorption and antioxidative activity, which is the base for many beneficial health effects of flavonoids.In some cases antiinfective properties are also effected.

View Article: PubMed Central - PubMed

Affiliation: Institut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften, Technische Universität Wien, Austria. hhalb@mail.zserv.tuwien.ac.at

ABSTRACT
Flavonoids and biochemically-related chalcones are important secondary metabolites, which are ubiquitously present in plants and therefore also in human food. They fulfill a broad range of physiological functions in planta and there are numerous reports about their physiological relevance for humans. Flavonoids have in common a basic C(6)-C(3)-C(6) skeleton structure consisting of two aromatic rings (A and B) and a heterocyclic ring (C) containing one oxygen atom, whereas chalcones, as the intermediates in the formation of flavonoids, have not yet established the heterocyclic C-ring. Flavonoids are grouped into eight different classes, according to the oxidative status of the C-ring. The large number of divergent chalcones and flavonoid structures is from the extensive modification of the basic molecules. The hydroxylation pattern influences physiological properties such as light absorption and antioxidative activity, which is the base for many beneficial health effects of flavonoids. In some cases antiinfective properties are also effected.

Show MeSH