Kinetic and thermodynamic study of 2′-hydroxy-8-methoxyflavylium. Reaction network interconverting flavylium cation and flavanone

Petrov, Vesselin; Diniz, Ana; Cunha-Silva, Luı́s; Parola, A. Jorge; Piña, Fernando

doi:10.1039/c3ra40846a

Cited by 14 publications

(6 citation statements)

References 22 publications

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“…Considering the functional groups of the colour substances of the extracts, one of the possible bindings is the hydrogen bond that forms between the hydrogen and oxygen atoms of the carboxyl and hydroxyl groups of the teak leaf extract's colour molecules and the oxygen and hydrogen atoms of the carboxyl and amino groups of the hair protein. Another possibility is that some colour substances of the flavonoid groups could switch to flavylium cation form, 34 which may be adsorbed onto the surface of the hair by electrostatic forces. However, both hydrogen bond interaction and electrostatic forces have a weak interaction.…”

Section: Resultsmentioning

confidence: 99%

Utilisation of Tectona grandis (teak) leaf extracts as natural hair dyes

Tibkawin

Suphrom

Nuengchamnong

et al. 2021

Coloration Technology

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Hair dye products are popular worldwide, and are most used by women in Europe and the USA. 1 Hair dyeing involves treating hair with natural and/or synthetic dyes to cover greying hair or to change the natural hair colour, according to the current fashion. Permanent hair dye products containing synthetic dyes are the most popular, but they cause allergic contact dermatitis in hairdressers and frequent users. 2 Synthetic hair dyes are also considered to be environmentally unfriendly and non-renewable.Natural hair dyes are becoming more and more in demand due to their conceivably greater safety, eco-friendliness and development from renewable resources. Accordingly, hair dye manufacturers and researchers have been investigating new sources of natural dyes and identifying their biological activities, colour characteristics, dyeing properties, formulations and safe use. [3][4][5] Natural dyes are colourants derived from plants, animals or minerals. Plants are the largest source of a wide variety of dyes given their extreme biodiversity, and many plants have traditionally been used as hair dyes in many

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Section: Resultsmentioning

confidence: 99%

Utilisation of Tectona grandis (teak) leaf extracts as natural hair dyes

Tibkawin

Suphrom

Nuengchamnong

et al. 2021

Coloration Technology

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“…The number, nature, and position of the substituents can modulate the metamorphic systems generated by flavylium cations. It is the case of those possessing a hydroxyl substituent in position 2′, see Scheme , because a flavanone is introduced in the metamorphic system. − …”

Section: Examples Of Molecular Metamorphosis Systemsmentioning

confidence: 99%

Achieving Complexity at the Bottom: Molecular Metamorphosis Generated by Anthocyanins and Related Compounds

et al. 2021

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The concept of molecular metamorphosis is described. A molecule (flavylium cation) generates a sequence of other different molecules by means of external stimuli. The reversibility of the system allows for the flavylium cation to be recovered by other external stimuli, completing one cycle. Differently from supramolecular chemistry, molecular metamorphosis is not a bottom-up approach. All events occur at the bottom. The procedures to characterize the kinetics and thermodynamics of the cycles are summarized. They are based on direct pH jumps (addition of a base to the flavylium cation) and reverse pH jumps (addition of an acid to equilibrated solutions at higher pH values). Stopped flow is an indispensable tool to characterize these systems. The following metamorphic cycles will be described to illustrate the concept: (i) introducing the flavanone in the metamorphic system and illustrating the concept of a timer at the molecular level; (ii) response of the flavylium-based metamorphosis to light inputs and the write-lock-read-unlock-erase molecular system; (iii) a one-way cycle of direct–reverse pH jumps; (iv) interconversion of the flavylium cation with 2,2′-spirobis[chromene] derivatives; (v) 6,8 A-ring substituent rearrangements.

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“…If pH keeps rising, the anionic forms start to accumulate, shifting the color of medium to green, when the ionized chalcone and ionized quinoid are in the equilibrium state at pH 8-10 [Levi et al, 2004]. At pH values greater than 12, dianion chalcone is the major compound, producing a yellow color in the solution [Petrov et al, 2013] (see Figure 2).…”

Section: Stability Of Anthocyaninsmentioning

confidence: 99%

Pigmented Maize (Zea mays L.) Contains Anthocyanins with Potential Therapeutic Action Against Oxidative Stress - A Review

Magaña-Cerino¹,

Peniche-Pavía²,

Tiessen³

et al. 2019

Pol. J. Food Nutr. Sci.

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Different maize (Zea mays L.) varieties have been used for thousands of years as a healthy food source in Mesoamerica including pigmented maize. Maize ingestion could contribute to the reduction in the rate of non-communicable diseases and, in turn, to its function as an adjuvant in their management. These diseases are mainly associated with oxidative stress, which is characterized by a redox cell imbalance produced due to pro-oxidant molecules accumulation, inducing irreversible damages. Although the endogenous antioxidant defense system is effi cient, exogenous antioxidants are necessary to help to prevent this damage. Bioactive compounds, like anthocyanins, contained in dietary plants exert a major activity against oxidative stress. Could the maize anthocyanins play a curative, preventive or complementary role in the treatment of chronic diseases? Here, we describe the occurrence of anthocyanins from pigmented maize and their chemical structures. Furthermore, the biosynthesis, bioavailability, and stability are also summarized. Finally, many in vitro and in vivo studies of maize anthocyanins are discussed that demonstrated their nutraceutical potential, antioxidant capacity, and other biological effects. Given the importance of the biological properties of maize anthocyanins, it is necessary to understand the current knowledge and propose further research or clinical studies which allows us to better elucidate the biological mechanism of maize anthocyanins derivatives of several varieties and processes of cooking and combination with other ingredients to enhance their nutritional and health benefi ts.

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Kinetic and thermodynamic study of 2′-hydroxy-8-methoxyflavylium. Reaction network interconverting flavylium cation and flavanone

Cited by 14 publications

References 22 publications

Utilisation of Tectona grandis (teak) leaf extracts as natural hair dyes

Utilisation of Tectona grandis (teak) leaf extracts as natural hair dyes

Achieving Complexity at the Bottom: Molecular Metamorphosis Generated by Anthocyanins and Related Compounds

Pigmented Maize (Zea mays L.) Contains Anthocyanins with Potential Therapeutic Action Against Oxidative Stress - A Review

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