Isolation and structure elucidation of novel phenolic constituents from Sorbus domestica fruits

In the framework of the detailed phytochemical analysis of Sorbus domestica fruits at several maturity stages and additively to the phenolic compounds elucidated by LC-DAD-MS (ESI+), ten more, novel phenolic compounds were isolated after preparative work and their structure elucidation was achieved with UV–vis, NMR (1H, 13C, COSY, HSQC, HMBC, NOESY, TOCSY, ROESY), LC-DAD-MS (ESI+) and HR-NanoESI-QqTOF-MS/MS. The novel compounds belong to the categories of hydroxybenzoic acid derivatives (Compounds 1, 2, 3), polyphenolic phenylpropanoid derivative (Compound 4), quercetin glycosides (Compounds 5, 6), flavanol glycoside (Compound 7), quercetin dimmer (Compound 8) and biphenyls (Compounds 9, 10). Their structures were established as: Vannilic acid 4-O-α-L-rhamnoside (1), protocatechuic acid anhydrite (2), trivanilloyl-(1,3,4-trihydroxybenzol) ester (3), 3-{4-(bis[4-hydroxy-3-(5-hydroxypentanoyloxy) phenyl) methoxy]-3,5-dihydroxy phenyl} propanoic acid (4), quercetin 3-O-β-D-glucopyranosyl(1′′′→2′′)-α-L-rhamnosyl(1′′′′→3′′′)-α-L-rhamnosyl(1′′′′′→3′′′′)-α-L-arabinofuranoside, quercetin 3-O-α-L-rhamnosyl(1′′′→3′′)-β-D-glucopyranoside (6), 5,7,3′,6′-tetrahydroxyflavanol 7-O-β-D-glucopyranoside (7), (7-O-4′′′, 4′O-7′′) quercetin dimmer (8), [2,2′-dihydroxy, 4-(propionic acid hexyl ester), 4′-(propionic acid heptyl ester)] biphenyl (9) and [2,6,2′,6′-tetrahydroxy, 4,4′-bis-(propionic acid hexyl ester)] biphenyl (10).