47863-30-9

Upstream product

• 83554-46-5 C₂₉H₃₆O₁₈ 
• 133-89-1 UDP-glucose 
• 18470-06-9 malvidin 3-O-glucoside 
• 82211-02-7 malvidin-3,5-di-O-β-D-glucopyranoside 

Downstream Products

• 83554-47-6 2-(4-Hydroxy-3,5-dimethoxy-phenyl)-3,5-bis-((2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-hydroxymethyl-tetrahydro-pyran-2-yloxy)-chromen-7-one 
• 83554-46-5 C₂₉H₃₆O₁₈ 

Relevant academic research and scientific papers

Molecular and biochemical characterization of the UDP-glucose: Anthocyanin 5-O-glucosyltransferase from Vitis amurensis

Abstract Generally, red Vitis vinifera grapes only contain monoglucosidic anthocyanins, whereas most non-vinifera red grapes of the Vitis genus have both monoglucosidic and bis-glucosidic anthocyanins, the latter of which are believed to be more hydrophilic and more stable. Although previous studies have established the biosynthetic mechanism for formation of monoglucosidic anthocyanins, less attention has been paid to that of bis-glucosidic anthocyanins. In the present research, the full-length cDNA of UDP-glucose: anthocyanin 5-O-glucosyltransferase from Vitis amurensis Rupr. cv. 'Zuoshanyi' grape (Va5GT) was cloned. After acquisition and purification of recombinant Va5GT, its enzymatic parameters were systematically analyzed in vitro. Recombinant Va5GT used malvidin-3-O-glucoside as its optimum glycosidic acceptor when UDP-glucose was used as the glycosidic donor. Va5GT-GFP was found to be located in the cytoplasm by analyzing its subcellular localization with a laser-scanning confocal fluorescence microscope, and this result was coincident with its metabolic function of modifying anthocyanins in grape cells. Furthermore, the relationship between the transcriptional expression of Va5GT and the accumulation of anthocyanidin bis-glucosides during berry development suggested that Va5GT is a key enzyme in the biosynthesis of bis-glucosidic anthocyanins in V. amurensis grape berries.

Chemical synthesis of hydroxycinnamic acid glucosides and evaluation of their ability to stabilize natural colors via anthocyanin copigmentation

This work describes the chemical synthesis of O-aryl-β-D-glucosides and 1-O-β-D-glucosyl esters of hydroxycinnamic acids. In particular, O-aryl-β-D-glucosides were efficiently prepared via a simple diastereoselective glycosylation procedure using phase transfer conditions. Despite the lability of its ester linkage, 1-O-β-D-caffeoylglucose could also be obtained using a Lewis acid catalyzed glycosylation step and a set of protective groups that can be removed under neutral conditions. Hydroxycinnamic acid O-aryl-β-D-glucosides were then quantitatively investigated for their affinity for the naturally occurring anthocyanin malvin (pigment). Formation of the π-stacking molecular complexes (copigmentation) was characterized in terms of binding constants and enthalpy and entropy changes. The glucosyl moiety did not significantly alter these thermodynamic parameters, in line with a binding process solely involving the polyphenolic nuclei.

The hemiacetal-cis-chalcone equilibrium of malvin, a natural anthocyanin

In slightly acidic aqueous solutions, malvin essentially exists, in a stable form, as a fast equilibrating reaction between a ring structure, the hemiacetal B, and a chain structure, the cis-chalcone CE.The temperature-jump technique has been used for the determination of the relaxation time τ characterizing this equilibrium.At 20 deg C τ-values were found to be in the range 1 s (for the more acidic solutions) to 2 x 10-4 s (for the neutral solutions).Both buffered and unbuffered solutions were investigated.It was found that τ is largly dependent upon pH andupon the concentration of the buffer.For instance, at constant pH, a plot of the observed first-order rate constant τ-1 versus the acetic acid - sodium acetate buffer concentration shows a nonlinear variation that can only be interpreted as a change in the proton transfer rate-limiting step with the buffer concentration.At 20 deg C, the constant K = E>/ is 0.25 (+/- 0.05) and the enthalpy change ΔH associated with this equilibrium is 20.7 (+/-2) kJ mol-1.Therefore, increasing the temperature greatly enhances the stability of the open cis-chalcone isomer.Possible implications arising from the existence of a fast chemical ring-closure reaction, in the case of natural anthocyanins, for the biosynthesis of flavonoids are discussed.In particular, it is suggested that, along with the main biosynthetic pathway to flavonoids, a minor pathway involving the anthocyanin cis-chalcone CE could also occur under favorable circumstances.Physico-chemical conditions in the plant organelles containing flavonoids (vacuoles) make this alternative plausible.

MALONATED ANTHOCYANINS IN MALVACEAE: MALONYLMALVIN FROM MALVA SYLVESTRIS

A new anthocyanin, malvidin 3-(6"-malonylglucoside)-5-glucoside has been characterized in both wild and cultivated forms of Malva sylvestris.Thus the classic source of the anthocyanin, malvin, actually contains the pigment in the flowers in malonated form.Malonated anthocyanins were also detected in Althaea rosea, Lavatera olbia and a Sphaeralcea sp. but they were not present in five other species in the family. - Keywords: Malva sylvestris; Malvaceae; mallow; flowers; malvidin 3-(6"-malonylglucoside)-5-glucoside; malvin.