Isolation of Bilberry Anthocyanidin 3‑Glycosides Bearing ortho-Dihydroxyl Groups on the B Ring by Forming an Aluminum Complex and Their Antioxidant Activity

• Published in: Journal of agricultural and food chemistry Vol. 60; no. 42; pp. 10634 - 10640
• Main Authors: Asada, Takayuki, Tamura, Hirotoshi
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 24.10.2012
• Subjects: aluminum; Aluminum - chemistry; aluminum chloride; Anthocyanins - chemistry; Anthocyanins - isolation & purification; antioxidant activity; Antioxidants - chemistry; Biological and medical sciences; cyanidin; delphinidin; ethanol; Food industries; Fundamental and applied biological sciences. Psychology; Glycosides - chemistry; ions; petunidin; Vaccinium myrtillus - chemistry; Anthocyanidin 3-glycoside; Al3; ortho-dihydroxyl selectivity; DPPH; complex pigments; Selectivity; Al; Antioxidant; Vaccinium; Dicotyledones; Angiospermae; Pigments; Anthocyanidin; Isolation; Spermatophyta; Glycoside; Ericaceae
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf302476n

Bilberry anthocyanin bearing an ortho-dihydroxyl group on the B ring was selectively isolated by complex formation with flavocommelin and aluminum ions (Al3+). The interaction between the anthocyanins, flavocommelin, and Al3+ might have happened in a manner similar to rigid supramolecules, such as commelinin, protocyanin, and other complex pigments. Complex blue pigment (CP, 8.85 ± 0.26 mg) with Al3+ was formed from 18.6 mg (15 μmol) of bilberry pigment, 18.2 mg (30 μmol, 2.0 equiv) of flavocommelin, and 0.03 mL of 0.5 M aluminum chloride aqueous solution (15 μmol, 1.0 equiv), yielding 36.5 ± 0.7% recovery of anthocyanins in the complex after precipitation by ethanol. Consequently, anthocyanins bearing ortho-dihydroxyl groups on the B rings (delphinidin 3-glycosides, cyanidin 3-glycosides, and petunidin 3-glycosides) predominating (98.0 ± 0.2%) in the complex were selectively isolated in a dose-dependent manner by the addition of Al3+, increasing the antioxidative activity of the mixture of anthocyanins.