Flavonoid glycosides from Pouteria obovata (R. Br.) fruit flour Irene Dini * Dipartimento di Chimica delle Sostanze Naturali, Università di Napoli ‘‘Federico II”, via D. Montesano, 49, 80131 Naples, Italy article info Article history: Received 13 April 2010 Received in revised form 13 May 2010 Accepted 6 July 2010 Keywords: Lucuma Sapotaceae Phenolic acid Flavonoids content NMR abstract Three unknown dihydroflavanol glycosides: 2R,3R-4 0 O-methyl dihydrokaempferol 7-O-[3 00 -O-acetyl]-b-D- glucopyranoside (1), 2R,3R-4 0 -O-methyl dihydrokaempferol 7-O-b-D-b-L-xylopyranosyl-(1 000 ? 6 00 )-[3 00 -O- acetyl]-b-D-glucopyranoside (2), 2R,3R-4 0 -O-methyl dihydrokaempferol 3-O-b-D-b-L-xylopyranosyl- (1 000 ? 6 00 )-[3 00 -O-acetyl]-b-D-glucopyranoside (3), together with gallic acid (4) were isolated from the n-butanol fraction of Pouteria obovata fruit flour by chromatographic methods and their structures were elucidated on the basis of CD, UV, MS, monodimensional NMR ( 1 H and 13 C) and bidimensional NMR (COSY, HSQC and HMBC). The quantitative analysis of flavonoids and phenols were also reported. Total phenolic amount (51.1 ± 14.1 mg GAE/1000 g; p< 0.0006) and flavonoid content (153.2 ± 3.5 mg CE/100 g; p< 0.004) were detected spectrophotometrically. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction In search of food rich in bioactive compounds, special attention is paid to Pouteria obovata (lucuma). It is a subtropical fruit of An- dean origin belongs to the Sapotaceae family. This exotic Peruvian fruit is also known as the ‘‘Gold of the Incas”. It is a rare case of a food of ancient cultivation, little-known outside its homeland that has recently found a place in modern food processing. Lucuma pulp is popular in drinks, puddings, pies, cookies, and cakes. An unusual advantage is that the fruit, when ripe, can be dried and milled into a flour, that is easily stored and can provide a tasty treat even years later (OIA, 1989). The whole fruit powder is versatile and tasty, blending easily and well with ice-creams, baby food, yogurts, pies, cakes, cookies, smoothies, chocolate bars and desserts (Morton, 1987). The aim of this work is the study of phenolic compounds from the dehydrated powdered product to make an appropriate nutraceutical labelling available in order to enhance the value of this product. Indeed, over the last decade or so, manufacturers have responded to consumer demands for more healthy foods, using dried fruits as key ingredients to create tasty and healthier food products. Dried fruits act as natural sweeteners in sweet and savoury applications, as fat replacers, thickeners, humectants and bases for other flavour and colour profiles, and as functional ingredients because they contain phytochemicals, chemical com- pounds that occur naturally in plants that may affect health (Bana- siak, 2003). There are several major groups of phytochemicals, among these the phenols, which include a large subgroup of chem- icals called flavonoids (polyphenols), that can prevent chronic dis- eases, such as cancer and heart disease. Phenols (including some flavonoids) act as antioxidants. Oxidative stress has been linked to cancer, aging, atherosclerosis, ischemic injury, coronary heart disease, heart attacks, inflammation and neurodegenerative dis- eases (Parkinson’s and Alzheimer’s) (Robards, Prenzler, Tucker, Swatsitang, & Glover, 1999). In addition to the pharmacological activities, a wide array of antimicrobial activity has also been attributed to flavonoids including antibacterial (Gibbons, 2008) and antifungal (Cao et al., 2008) activities making natural flavo- noids important as phytoalexins and phytoanticipins in the plant (Mc Nultya et al., 2009) and as antimicrobial food preservatives (Galal, 2006; Naidu, Bidlack, & Crecelius, 2000). 2. Materials and methods 2.1. Plant material Dehydrated powdered fruit, available in the market, coming from Lima (Perú) was purchased in September, 2009, and the ref- erence specimens deposited at the Dipartimento di Chimica delle Sostanze Naturali, Napoli (Italy). 2.2. Spectroscopic and chromatographic analysis The UV–Vis spectrophotometer spectra were recorded on a Jas- co V-530 (Easton, USA). The FABMS spectra (recorded in a glycerol matrix) were taken on a Prospec Fisons mass spectrometer (Dan- vers, NJ, USA). ESIMS experiments were performed on an Applied Biosystem API 2000 triple-quadrupole mass spectrometer (War- 0308-8146/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodchem.2010.07.013 * Tel.: +39 81 678535; fax: +39 81 678552. E-mail address: irdini@unina.it Food Chemistry 124 (2011) 884–888 Contents lists available at ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem