Recent Advances in Polyphenol Research, Volume 1, pp. 177-178 (2008)
edited by Fouad Daayf, Vincenzo Lattanzio

Recent Advances in the Field of Anthocyanins — Main Focus on Structures
Øyvind M. Anderson

The first pyranoanthocyanidin isolated from intact plants, rosacyanin B (35) (Fig. 7.3) was isolated in small amounts from the petals of Rosa hybrida cv. 'M'me Violet' (Fukui et al., 2002). Rosacyanin B is very stable in acidic alcoholic solutions, however, under neutral or weakly acidic aqueous conditions it is precipitated before forming the colorless pseudobase. The structure of this violet pigment, which was revealed mainly by high-resolution fast atom bombardment mass spectrometry (FAB MS) and NMR, contains no sugar units. However, in a recent paper the same group showed that rosacyanin B was connected to tannins in two novel pigments, rosacyanins A1 and A2 (Fukui et al., 2006). These blue pigments had a common chromophore, which contained cyanidin with a galloyl group link between positions 4 and 5 of the hydroxy group of the flavylium nucleus, and tellimagrandin 1 and 2. respectively, at C-3 of the cyanidin nucleus. These are the first known natural pigments in which the flavylium nucleus binds to ellagitannins.

Fig 7.3 Rosacyanin B (35) has been isolated from the violet petals of Rosa hybrida cv. 'M'me Violet' (Fukil et al., 2002). The 3-glucoside (37) and 3‑[6‑(malonyl)glucoside] (38) of 5‑carboxypyranocyanidin were isolated from extracts of red onion (Fossen & Andersen. 2003), while 5-carboxypyranopelargonidin 3-glucoside (36) has been isolated from extracts of strawberries (Andersen et al., 2004). mal, malonyl.