Impact of a Water‐Soluble Gallic Acid‐Based Dendrimer on the Color‐Stabilizing Mechanisms of Anthocyanins

Abstract

The interaction of two anthocyaninsw ith aw atersoluble polyanionic dendrimerw as studied through UV/Vis, stopped-flow,a nd NMR spectroscopy. Cyanidin-3-glucoside (cy3glc)r evealed as tronger interactiont han malvidin-3-glucoside (mv3glc) at pH 1a ccording to their apparent association constants. Ah igher color increased was also obtained for cy3glca tp H3.5 as ar esult of this strongeri nteraction.A high-frequency chemical shift of the cy3glc aromatic protons suggest the formation of ionic pairs. The interaction parame-ters (K % 700 m À1 , n % 295) indicated the binding of approximately two anthocyanin molecules by each sulfate group. The equilibriuma nd ratec onstantso fc y3glc in the presence of dendrimer showed an increased stability of the flavylium cationand ahigher protectiono fthis speciesf rom hydration (pK' a and pK h increased almost one pH unit).T he tuning and color stabilizationo fa nthocyanins by using this dendrimer allow novel applications as colorimetric sensors for food packaging.[a] L. Cruz, N. Mateus,V .d eFreitas Supporting Information and the ORCID identification number(s) for the author(s) of this articlecan be found under: https://doi.

Heterofunctional carbosilane polyphenolic dendrons: new antioxidants platforms

“…Chemical shis are given in ppm relative to internal deuterated solvent peaks. When necessary, the assignment of resonances was done from bidimensional { 1 H- 13 C}-HSQC-2D-NMR, { 1 H- 13 C}-HMBC-2D-NMR, { 1 H-1 H}-COSY-2D-NMR and 1 H-DOSY-2D-NMR experiments. Elemental analyses were performed on a LECO CHNS-932 instrument.…”

“…Several strategies for the functionalisation of dendritic structures with polyphenols through hydrophobic/hydrophilic interactions or covalent bonds have been reported showing engaging antioxidant activities. [13][14][15][16][17] However, not only the functional groups but also the nature of the dendritic scaffold plays a crucial role in their biological activity. 18 Carbosilane dendrimers present C-C and C-Si bonds providing a hydrophobic structure and enhancing their interaction with biological membranes.…”

Anthocyanin Color Stabilization by Host-Guest Complexation with p-Sulfonatocalix[n]arenes

“…In this context, calix [n]arenes (Cn) belong to the class of macrocyclic compounds that have shown many interesting recognition properties, serving as host molecules for a wide range of organic and inorganic compounds [14]. Cn macrocycles are typically waterinsoluble, therefore their functionalization to improve water solubility is of great interest for biologically relevant applications, such as enzyme inhibition, ion channel blocking, and anti-viral properties, among others [15][16][17][18].…”

“…For this reason, it is important to increase the flavylium domain along the pH scale. Upward pK' a shifts in some flavylium derivatives, including anthocyanins, have been previously achieved by complexation with supramolecular receptors such as cucurbiturils [10,11], polymers [12,13] and dendrimers [14].…”

Preparation of blueberry anthocyanin liposomes and changes of vesicle properties, physicochemical properties, in vitro release, and antioxidant activity before and after chitosan modification

“…Encapsulation is an important way to protect environmentally sensitive bioactive molecules (Shishir et al., 2018). So far, many carrier systems have been developed and used to encapsulate anthocyanins to enhance storage and gastrointestinal stability and to improve the bioavailability and delivery of anthocyanins at target points, such as micelles, dendrimers, complex condensates, cyclodextrins, solid lipid nanoparticles, cellulose nanocrystal, polyelectrolyte complex, nano liposome, and different polymer formulations (Cruz et al., 2019; Shaddel et al., 2018; Flores et al., 2015; Lin et al, 2019). In this study, we focused on the application of lipid‐based anthocyanin release system.…”