Anthocyanin from strawberry (Fragaria ananassa) with the novel aglycone, 5-carboxypyranopelargonidin.

摘要: Abstract An anthocyanin, 1 , with the novel 4-substituted aglycone, 5-carboxypyranopelargonidin, was isolated in small amounts from acidified, methanolic extract of strawberries, Fragaria ananassa Duch., by preparative HPLC after purification partition against ethyl acetate, Amberlite XAD-7 and Sephadex LH-20 column chromatography. It identified mainly 2D NMR spectroscopy electrospray LC-MS as 3- O -β-glucopyranoside 5-carboxy-2-(4-hydroxyphenyl)-3,8-dihydroxy-pyrano[4,3,2- de ]-1-benzopyrylium, an anthocyanidin which is homologous to 5-carboxypyranomalvidin (vitisidin A) reported red wines 5-carboxypyranocyanidin recently onions. By comparison UV–Vis absorption spectra, showed contrast 2 pelargonidin -β-glucopyranoside, a local peak around 360 nm, hypsochromic shift (8 nm) visible maximum, lack distinct UV 280 nm. The similarities between spectra various acidic neutral buffer solutions implied restricted formation instable colourless equilibrium forms, are typical for most anthocyanins weakly solutions. molar absorptivity (ϵ) varied little pH contrary similar values instance major anthocyanin strawberry, . However, revealed higher ϵ -values than at all except 5.1. At 5.1, -value (6250) nearly four times corresponding value (1720), potential 5-carboxypyranopelargonidin derivatives colorants 5. colours buffered 1.1 6.9 have been described CIELAB coordinates h ab (hue angle), C* (chroma), L* (lightness).