Valentina Sinisi, Federico Berti, Cristina Forzato, Fabio Benedetti, Luciano Navarini, Lieve Naesens, Annelies Stevaert and Kurt Vermeire
Università degli Studi di Trieste, Dipartimento di Scienze Chimiche e Farmaceutiche, via L. Giorgieri 1, I-34127 Trieste, Italy
Coffee, one of the most diffused beverage in the world, contains hundreds of different compounds.
Among them, chlorogenic acids (CGAs), that belong to the polyphenols family, acquire more and more importance, due to their key-role in determining the coffee flavor, their beneficial health properties, and their possible use as marker to control the industrial process [1, 2]. The roasting of green coffee beans causes a partial loss of CGAs and the appearance of their degradation products, such as their lactones, whose amount depends on the roasting degree. Some of this lactones were synthesized and fully characterized [3, 4], namely: 3,4-Odicaffeoyl- 1,5-γ-quinide, 3-O-[3,4-(dimethoxy)cinnamoyl]-1,5-γ-quinide, 3,4-O-bis[3,4-(dimethoxy)cinnamoyl]-1,5-gquinide, and 1,3,4-O-tris[3,4-(dimethoxy)cinnamoyl]-1,5-γ-quinide (Fig. 1). A direct synthesis of the tri-substituted quinide was also tuned up, starting from D-(-)-quinic acid and 3,4-dimethoxycinnamoyl chloride .
Figure 1. Molecular structures of 3,4-O-dicaffeoyl-1,5-γ-quinide (a), 3-O-[3,4-(dimethoxy)cinnamoyl]-1,5-γ-quinide (b), 3,4-O-bis[3,4-(dimethoxy)cinnamoyl]-1,5-γ-quinide (c), and 1,3,4-O-tris[3,4-(dimethoxy)cinnamoyl]-1,5-γ-quinide (d).
The specific binding constants to Human Serum Albumin (HSA), more exactly to its Sudlow site I, were measured in physiological conditions by fluorescence spectroscopy, reaching interesting KD values, in the range 3-30 mM . In addition, the antiviral properties of these compounds have been evaluated against a panel of different viruses. Some promising micromolar activities were detected against influenza virus and HIV. Moreover, compound 3-O-[3,4- (dimethoxy)cinnamoyl]-1,5-γ-quinide exerted antiviral activity against respiratory syncytial virus (RSV) in the nanomolar range. Our data suggest that chlorogenic lactones from coffee may be considered as promising antiviral candidates.
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 Sinisi, V.; Boronová, K.; Colomban, S.; Navarini, L.; Berti, F.; Forzato, C. Synthesis of mono, di and tri-3,4- dimethoxycinnamoyl-1,5--quinides. Eur. J. Org. Chem., 2014, 1321-1326. DOI: 10.1002/ejoc.201301657.