Dipartimento di Scienze Farmaceutiche “Pietro Pratesi” DOTTORATO DI RICERCA IN CHIMICA DEL FARMACO INDIRIZZO ANALISI FARMACEUTICA , BIOFARMACEUTICA E TOSSICOLOGICA CICLO XXIV EXTRACTION, PURIFICATION AND CHARACTERIZATION OF POLYPHENOLS FROM UVA DI TROIA AD ACINO PICCOLO SEEDS AND SKINS FOR THE DEVELOPMENT OF NEW NUTRITIONAL SUPPLEMENTS (CHIM/08) Tesi di Dottorato di: Dott.ssa DARIA CATALANO Matr. Nr. R08313 TUTOR: Ch.mo Prof. VENIERO GAMBARO COORDINATORE: Ch.mo Prof. ERMANNO VALOTI A.A. 2010-2011 Ai miei genitori ABSTRACT The aim of this Ph.D. project was to study the phenolic composition of Uva di Troia ad acino piccolo (Uva di Troia with small berry) seeds and skins in relation to the vinification process, in order to create a new nutritional supplement based on the benefits of the phenolics extracted. This grape biotype represents an autochthonous Vitis vinifera L. grape variety of Apulia region (South Italy) and is supposed to have significant levels of polyphenols and a great wine aging potential. Grape samples were collected at four different fermentation stages (from no fermentation to complete fermentation), called thesis . The extraction of seeds was performed with a multi-step extraction by maceration either with ethanol or acetone in water and the extracts obtained were characterized by Reversed Phase Liquid Chromatography coupled to Diode Array Detector (RPLC- DAD). Finally, extracts were successfully purified with Ethyl acetate. On the other hand, skins were subjected to a single step extraction with methanol and the extracts were analyzed by RPLC-UV; only Thesis 1 skin extract was also purified using a synthetic adsorbent resin. Data obtained show that the phenolic content of both grape seeds and skins decreases from the beginning of fermentation to the end of the process; these results are related to the extraction of the active compounds by the must during vinification. Moreover, Uva di Troia ad acino piccolo seeds represent a rich font of Flavan-3-ols and further studies will be conducted to produce new nutraceuticals based on this vegetable matrix. Particularly, Thesis 2 seeds represent the best fraction because the partial fermentation allows the concomitant production of wine and of the polyphenolic phytocomplex. ACKNOWLEDGEMENTS I express all my gratitude to all of those I had the pleasure to work with during this project, Prof.ssa Gabriella Roda, my faculty members and, especially, the research group directed by Prof. Veniero Gambaro. This work would not have been possible without the support of Dr. Sergio Fontana, general manager of Farmalabor Srl, who provided us grape samples and the opportunity to contribute to this important project. I am really grateful also to Dr. Giuseppe Mustich for the important help given to me in developing grape extraction and purification techniques, as well for the human support. Finally, I also extend my heartfelt thanks to my family. TABLE OF CONTENTS ABSTRACT........................................................................................................................ i ACKNOWLEDGEMENTS ................................................................................................ ii TABLE OF CONTENTS .................................................................................................... I 1. INTRODUCTION ........................................................................................................ 1 1.1 POLYPHENOLS ............................................................................................................................... 3 1.2 GRAPE POLYPHENOLS ................................................................................................................ 8 1.3 HEALTH EFFECTS ........................................................................................................................ 21 1.4 UVA DI TROIA .............................................................................................................................. 31 2. AIM OF THE PROJECT ............................................................................................ 33 3. MATERIALS AND METHODS ................................................................................. 38 3.1 GRAPE SAMPLES ........................................................................................................................ 39 3.2 MANUAL SEPARATION OF SEEDS AND SKINS ................................................................ 42 3.3 INSTRUMENTATION ................................................................................................................. 42 3.4 CHEMICALS AND REAGENTS ................................................................................................. 44 4. GRAPE SEED CHARACTERIZATION ....................................................................... 46 4.1 EXTRACTION CONDITIONS .................................................................................................... 47 4.2 UVA DI TROIA SEED LOSS ON DRYING............................................................................... 51 4.3 GRAPE SEED EXTRACTION ...................................................................................................... 51 4.4 TLC ANALYSES............................................................................................................................. 55 4.5 LC ANALYSES OF GRAPE SEEDS ............................................................................................ 59 4.6 PURIFICATION OF GRAPE SEED EXTRACTS ....................................................................... 68 4.7 EXTRACTION BY PERCOLATION ........................................................................................... 72 5. GRAPE SKIN CHARACTERIZATION ....................................................................... 74 5.1 LOSS ON DRYING OF UVA DI TROIA SKINS ...................................................................... 75 I 5.2 GRAPE SKIN EXTRACTION ...................................................................................................... 76 5.3 SKIN EXTRACTION RECOVERY .............................................................................................. 77 5.4 DETERMINATION OF TOTAL ANTHOCYANS .................................................................... 78 5.5 LC ANALYSIS OF GRAPE SKINS .............................................................................................. 80 5.6 PURIFICATION OF GRAPE SKIN EXTRACTS ....................................................................... 87 6. IN SEARCH OF t-RESVERATROL ............................................................................ 94 6.1 HYDROLYSIS OF GRAPE SKIN EXTRACTS ........................................................................... 95 6.2 ANALYSIS OF POLYDATIN ....................................................................................................... 97 6.3 ANALYSIS OF REVIDOX™ ...................................................................................................... 100 7. LC-MS/MS EXPERIMENTS .................................................................................... 102 7.1 APPARATUS ............................................................................................................................... 103 7.2 PREPARATION OF THE STD S ................................................................................................ 104 7.3 PREPARATION OF THE SAMPLES ....................................................................................... 104 7.4 MASS SPECTROMETER SETUP ............................................................................................. 105 7.5 LC-MS/MS ANALYSIS OF THE SAMPLES .......................................................................... 107 8. CONCLUSIONS ...................................................................................................... 109 APPENDICES .............................................................................................................. 114 REFERENCES .............................................................................................................. 154 II 1. INTRODUCTION 1. Introduction 1. INTRODUCTION The Ph.D. project reported herein is born from the partnership between the University of Milan and Farmalabor Srl, an Apulian pharmaceutical society with base in Canosa di Puglia (BAT Province, Apulia, Italy). Farmalabor has obtained a financial support by Apulia Region institution in its operative programme 2007/2013 for the development of a project, whose title is: “ Valorizzazione delle qualità salutistiche dell’Uva di Troia ad acino piccolo per la produzione di integratori nutrizionali” , that means “Valorisation of the beneficial properties of Uva di Troia with small berry for the production of nutritional supplements”. In order to realize this project, Farmalabor has also created an experimental vineyard of Uva di Troia ad acino piccolo . Uva di Troia represents an autochthonous Vitis vinifera L. grape variety of Apulia region and can exist as two different biotypes in relation to the berry size. The small berry biotype, i.e. Uva di Troia ad acino piccolo is also called “canosina” because of the city of Canosa where this variety is today cultivated. This particular grape biotype is nowadays considered unproductive from the oenological point of view, thus, its cultivations are going to be replaced with more productive vineyards. However, recent studies confirmed significant levels of polyphenols in