StatusThe thesis was presented on the 10 April, 2009
Approved by NCAA on the 18 June, 2009
Abstract– 0.33 Mb / in romanian
ThesisCZU 547+542.958.2+ 678.746.47
1.92 Mb /
The purpose of the present work is the use of componds obtained from secondary winery products in the decrease of nitrite and N-nitrosamine concentration and determination of inhibition mechanisms in vitro and in vivo and the determination of antioxidant activity using the DPPH• and ABTS•+ tests.
In this work, was established the antioxidant capacity, wich decrease in the series Que > DFH3Na > DFH4 ≥ (+)Ct > EDMD > Rezv >> EDMT , and it’s dependend on the molecular structure of antioxidant. Esterification of carboxilic groups of DFH4, gives the decrease of antioxidant capacity of EDMD. The highest antioxidant activity occurred in Que and nonoxidated oenotanins (among grapes extracts). There was determined the direct correlation between the anti-oxidant activity of the compounds obtained from secondary winery products and their reducing properties in reaction with the nitrosation agents.
The inhibition of nitrosation process af secondary amines by derivates of DFH4 (EDMD şi DFH3¬Na) was obtanied.
For the first time empirically demonstrates the endogenous nitrosation of nornicotine (on rats) with the formation of N-nitrosonornicotine, as well as the inhibition of the endogenous formation of this nitrosamine. It was proved that the inhibition effect of the dihydrofumaric acid during the process of nornicotine nitrosation in vivo is comparable with that of the polyphenols and grape seeds extract. Tartaric acid inhibits the in vivo nitrozation of nornicotine, but don’t demonstrate the same properties in vitro.
Keywords: N-Nitrosamine, N-nitroso compounds, endogenous nitrosation, nitrite, inhibition, polyphenol, secondary winery products, grape seeds extract, antioxidant, DPPH, ABTS, amine.