beta-ionone and alpha-terpineol

The impacts of fruit zone leaf removal on volatile and anthocyanin compositions of Pinot noir wine were investigated over two growing seasons. Wine volatiles were analyzed by multiple techniques, including headspace solid phase microextraction-GC-MS (HS-SPME-GC-MS), headspace-GC-FID (HS-GC-FID) and stir bar sorptive extraction-GC-MS (SBSE-GC-MS). Fruit zone leaf removal affected the concentration of many grape-derived volatile compounds such as terpene alcohols and C13-norisoprenoids in wine, although the degree of impact depended on the vintage year and severity of leaf removal. Fruit zone leaf removal resulted in greater concentrations of linalool, α-terpineol and β-damascenone but had no impact on other terpene alcohols or β-ionone. Fruit zone leaf removal had no consistent impact on C6 alcohols, volatile phenols, lactones, fermentation-derived alcohols, acids, or most esters. Fruit zone leaf removal increased anthocyanins in final wine.

Topics: Agriculture; Alcohols; Anthocyanins; Cyclohexane Monoterpenes; Cyclohexenes; Food Analysis; Fruit; Gas Chromatography-Mass Spectrometry; Hydrogen-Ion Concentration; Monoterpenes; Norisoprenoids; Oregon; Phenols; Plant Leaves; Solid Phase Microextraction; Temperature; Terpenes; Vitis; Wine

The present study was undertaken to investigate the inhibitory effects of beta-ionone, (-)-menthol, 1,8-cineole and alpha-terpineol on liver microsomal enzymes involved in the biotransformation of xenobiotic substances. The effects of beta-ionone and the foregoing monoterpenoid compounds on the activity of pentoxyresorufin-O-depentilase (PROD), a selective marker for CYP2B1, were determined in a pool of liver microsomes prepared from phenobarbital-treated rats. On the other hand, the inhibitory effects of these substances on the activities of ethoxyresorufin-O-deethylase (EROD), a marker for CYP1A1, and methoxyresorufin-O-demethylase (MROD), a marker for CYP1A2, were investigated in a pool of hepatic microsomes from beta-naphthoflavone-treated rats. Beta-ionone caused a concentration-related reduction of PROD activity with an IC50 value as low as 0.03 microM. The analysis of alterations produced by beta-ionone on PROD kinetic parameters (Lineweaver-Burk double-reciprocal plot) suggested that inhibition is non-competitive (Ki = 89.9 nM). Although being less potent than beta-ionone, 1,8-cineole (IC50 = 4.7 microM), (-)-menthol (IC50 = 10.6 microM) and terpineol (IC50 = 14.8 microM) also proved to be in vitro inhibitors of PROD reaction. Results also revealed that beta-ionone was a weak inhibitor of EROD (IC50 >100 microM) and MROD (IC50 >200 microM). Neither 1,8-cineole nor terpineol--tested in concentrations up to 150 microM--caused any decrease of EROD activity while (-)-menthol, at a concentration as high as 160 microM, produced only a slight reduction of the reaction rate. Terpineol (up to 150 microM) did not induce any reduction of MROD activity while 1,8-cineole (IC50 >300 microM) and (-)-menthol (IC50 >300 microM) caused only slight decreases of the reaction rate. The potent inhibitory effects on CYP2B1 suggest that beta-ionone, and the other monoterpenoids tested, may interfere with the metabolism of xenobiotics which are substrates for this isoenzyme.

Topics: Animals; Cyclohexane Monoterpenes; Cyclohexanols; Cyclohexenes; Cytochrome P-450 CYP1A1; Cytochrome P-450 CYP1A2; Cytochrome P-450 CYP1A2 Inhibitors; Cytochrome P-450 CYP2B1; Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Eucalyptol; Female; Liver; Menthol; Microsomes, Liver; Monoterpenes; Norisoprenoids; Oxidoreductases; Rats; Rats, Wistar; Terpenes