4-Hydroxy-P-ionone

The conversion of frans-retinyl acetate into retinoic acid in hamster organ culture,262 and of cis- and trans-rzimoxc acid into the 5,6-epoxy- and 4-oxo-derivatives and their glucuronides has been demonstrated.263 264 Strains of Aspergillus niger metabolize ionones and related compounds to oxygenated derivatives, some of which may be useful intermediates for carotenoid synthesis. The asymmetric oxidation of p-ionone to (25, 6/ ,7/ )-2,7-epoxydihydro-a-ionone (218) has been demonstrated.265 (i )-4-Hydroxy-p-ionone (219 X = OH)... 

Buten-2-one, 4-(4-hydroxy-2,6,6-trimethyl-1-cycIohexen-1-yl)- 4-hydroxy-p-ionone ... 

Fujimori, T., R. Kasuga, H. Kaneko, and M. Noguchi Isolation of R(-)-3-hydroxy-P-ionone from hurley tobacco Agr. Biol. Chem. Japan 38 (1974) 891-892. Fujimori, T., R. Kasuga, H. Kaneko, and M. Noguchi Isolation of 3-(4,8,12-trimethyltridecyl)furan (phyto-furan) from hurley tobacco Agr. Biol. Chem. Japan 38... 

As an example of the Shapiro reaction, the 2,4,6-triisopropylphenylsulphonylhydrazone of (-)-(3/ )-3-hydroxy-P-ionone (34) is treated with an excess of -BuLi in hexane in the presence of TMEDA to give the vinyllithium reagent 35 which, on condensation with the C27-aldehyde 36, furnishes the C4o-allylic alcohol 37 in 75% yield, en route to (3/ ,6 / )-P,E-carotene-3,19-diol [20] (Scheme 9). 

Figure 4.2. Principal norisoprenoid compounds in grape and wine. (29) TDN (1,1,6-trimethyl-l,2-dihydronaphthalene) (30) P-damascone (31) P-damascenone (32) vom-ifoliol (33) dihydrovomifoliol (34) 3-hydroxy-P-damascone (35) 3-oxo-a-ionol (36) 3-hydroxy-7,8-dihydro-P-ionol (37) oc-ionol (38) P-ionol (39) a-ionone (40) P-ionone (41) actinidols (42) vitispiranes (spiro [4.5]-2,10,10-trimethyl-6-methylene-l-oxa-7-decene) (43) Riesling acetal (2,2,6-tetramethyl-7,ll-dioxatricyclo[6.2.1.01,6] undec-4-ene).

Astaxanthin absorption and metabolism has been fairly well researched in birds, cmstaceans, and especially fish, but only a handful of studies report on its uptake and metabolism in humans and other mammals. In rat hepatocytes, astaxanthin was metabolized into two racemic compounds 3-hydroxy-4-oxo-(3-ionone and its reduced form, 3-hydroxy-4-oxo-7,8-dihydro-p-ionone. Both of these metabolites were also... 

Norisoprenoids detected in negligible amounts or not found in the free fraction of studied wines, were relatively abundant in the bound fraction. The Qs-norisoprenoid pattern was composed by 3-hydroxy-P-damascone, 3-oxo-a-ionol, 3-hydroxy-7,8-dihydro-(3-ionol and, in smaller concentrations, a-ionone and 4-oxo-isophorone. By contrast, (3-damascenone -detected in the free fraction in wines- was not detected in bound form as this compwimd is formed principally from the precursors 3-hydroxy-P-damascone and 3-hydroxy-7,8-dehydro-P-ionol the highest concentration of both compounds found in fraction of aroma of Rojal wines could be related to that in the free fraction Rojal wines paosented lower concentration of P-damascenone. 

The aroma of thermally processed tomatoes, such as tomato paste, is mainly determined by the presence of acetic and isovaleric (3-methylbutanoic) acids, 3-methylbutanal, methional, eugenol, 4-vinylguaiacol, dimethylsulfide, P-ionone and (E)-P-damascenone. There are other less active components, such as linalool, 4-hydroxy-2,5-dimethyl-2H-furan-3-one (furaneol) and its lower homologue... 

In addition to the character impact compound of raspberry, 4-(4-hydroxy-phenyl)-butan-2-one (raspberry ketone), alpha- and beta-ionone, geraniol, and linalool were concluded to be of importance in raspberry aroma (30). Its odor threshold was measured at 1-10 ig/kg. The ionones have chemical stracture similarities and potencies comparable to P-damascenone (11). 

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