Some Biological Activities of Vine Stilbens and New ... - Oiv2010.ge

engaged in an intense study in the direction of “Wine and health” to identify specifically the
stilben spectrum in red Georgian wines. At present, we have identified and determined
resveratrol dimmer ε-viniferin.
MATERIALS AND METHODS. We used the different types of naturally cleared red
wines made with Saperavi, Otskhanuri Sapere, Cabernet Sauvignon and Tavkveri species as
the objects of the study, in particular, dry table, naturally semi-sweet, semi-sweet and fortified
wines. For qualitative and quantitative analyses of trans-resveratrol, we extracted the wines in
advance with ethyl acetate and used the gained fraction for analyses. We used thin-layer
chromatography with silufol plates (20 cm x 20 cm), system: chloroform : methanol (80:20)
and denitrated sulfanilic acid as a developer. We defined the quantity of trans-resveratrol by
high-efficiency liquid chromatography in terms of gradient. The column of Nucleosil C 18 ,
eluent A: water + H3PO4; eluent B: acetonitrile+H3PO4, pH=3,5-4,0. Out of naturally cleared
dry table bulk wines made with the 2008 harvest of Saperavi and Cabernet Sauvignon, we
isolated the total stilbens with further treatment of their ethyl acetate fractions (Ribeiro de
Lima et al., 1999). We analyzed the gained fraction by high-efficiency liquid chromatography
in terms of gradient (the chromatograph made by “Varian”); UV detector/visible spectrum,
column – Microsorb 100 C18, 250X4,6 LxId (mm); 5µm – Particle Size. Eluent A: TF
(trifluoroacetic acid) 0,025% water solution; eluent B: AСN/AA, 80/20 (v/v); (Guebailia, et
al., 2006).
RESULTS AND DISCUSSION. The gained results demonstrate that the concentration of
trans-resveratrol in bulk wines depends on different factors, one of which is the generic factor.
In this respect, Saperavi and Otskhanuri Sapere are the most obvious examples. The
concentration of trans-resveratrol in bulk wines also changes according to the sugar content of
the must. In particular, within the range of 19,1-26,0%, the content of trans-resveratrol in the
red wines made of Saperavi with different sugar contents changes from 1,69 mg/l to 2,87
mg/l; for Otskhanuri Sapere (with the sugar content of 19,2%-22,4%), it is 1,25 mg/l 1,95
mg/l and for Cabernet Sauvignon (with the sugar content of 19,3%-22,7%), it is 1,15 mg/l to
2,25 mg/l. At this point, in addition to the generic factor, the factor of alcohol-content of the
pomace fermented is obviously seen. As for the wine type, it is seen as the factor making the
wines made with the same grape species significantly different from one another with their
concentration of trans-resveratrol. This is proved by the diagram in “Fig. 1”.
“Fig. 1”. Change of the concentration of trans-resveratrol according to the types of wine.
I – naturally semi-sweet, II – semi-sweet, III – dry, IV – fortified.
Among the naturally semi-sweet, semi-sweet, dry and fortified wines, the concentration of
trans-resveratrol is the highest in the fortified wine and is the least in the naturally semi-sweet
wine. Besides the above-mentioned factors, temperature and squeezing and mixing of
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