An examination of the carotene fractions extracted from Euglena gracilis Z and pressure-bleached Euglena mutants PR-1, PR-2, PR-3, and PR-4 revealed phytoene in mutants PR-1, PR-2, and PR-3. Photosynthetic E. gracilis Z cultured at different light intensities showed no detectable phytoene, nor was phytoene found in mutant PR-4. However, dark-cultured E. gracilis Z yielded readily assayable amou...

Vitamin A intake was assessed from dietary histories on 452 men with prostate cancer and 899 population controls in Hawaii during the period 1977-1983. In the group of men <70 years of age, there were no significant associations of this nutrient with risk for prostate cancer. In the men >70 years, however, risk increased directly with the amount of » ¡minili A consumed (relative risk of 2.0 f...

Ready to Drink (RTD) mango nectar was subjected to pulsed electric fields (PEF) processing. The effect of process parameters including pulse frequency (70-120 Hz) and pulse width (1524 μs) on carotenes, total plate count, coliforms, yeast and moulds and over all acceptability was studied using a response surface methodology. Mango nectar exhibited high retention of carotene content at higher fr...

The target sites o f three herbicides which inhibit carotenoid biosynthesis have been charac­ terized using H PLC analysis o f pigm ent extracts from two higher plant systems, carro t cell suspension cultures and barley seedlings. Diflufenican causes an accum ulation o f phytoene and phytofluene. D ichlorm ate causes accum ulation o f phytoene, phytofluene, ^-carotene, neurosporene and ß-zeacar...

We describe a procedure for quantitative determination of beta-carotene in human serum. The 0.1-mL serum sample is precipitated with ethanol containing the internal standard, dimethyl-beta-carotene, then extracted with hexane. This extract is injected onto a reversed-phase, "high-performance" liquid-chromatography column, and the carotenes are resolved and eluted with an acetonitrile/methylene ...

Compounds known to be inhibitors of mixed-function oxidase systems inhibited the aerobic synthesis of hydroxylated carotenoids in Staphylococcus aureus U-71. Growth of the cells in the presence of 2-diethylaminoethyl-2,2-diphenyl valerate, 2,4-dichloro-6-phenylphenoxyethylamine, 2,4-dichloro-6-phenylphenoxyethyldiethylamine, and piperonyl butoxide reduced the levels of the rubixanthins found in...

Caryocar brasiliense Camb. is a tree popularly known in Central Brazil as pequi. Its fruit contains carotenes, retinols, vitamin C, and polyphenols. These compounds possess antioxidant properties preventing excessive free radical formation and modulating the genotoxicity of physical and chemical agents in the body. However, at high concentrations these compounds can have recombinogenic and muta...

By applying microspectrophotometry to the sporangiophore of Phycomyces blakesleeanus wild-type and the albino car-10(-) type II, absorption spectra were obtained for 1- to 5-day cultures. Spectra in the growing-zone of the wild-type during Stage IVb, taken from 0.1 to 3 mm below the base of the sporangium, show two distinctly different spectra: one is more characteristic of a carotene, the othe...