Analysis and properties of carotenoids in vivo and in vitro

The purpose of this study was to develop a deeper understanding of the nature of carotenoid metabolism in the human and primate retina. We have sought to do this from two perspectives (1) through preparation and study of a carotenoid diketone that is a candidate metabolic product and (2) through measurement of the carotenoid distribution in the retinas of neonatal macaques. In this thesis we report the synthesis, purification, and characterization of the product using HPLC, UV/Vis, MS, 1H-NMR. The data obtained are all consistent with the proposed β,β-carotene-3,3\u27-dione. There has been no thorough study of the development of the macular pigment during the earliest stages of life immediately following birth. In this study 30 macaque retinas ranging from 148 days of gestation to 15 years in age were analyzed. The amounts of the carotenoids, lutein, R,R-zeaxanthin, and meso-zeaxanthin were determined using C 18 reversed-phase column and chiral, normal-phase column HPLC

Macular pigment response to a supplement containing meso-zeaxanthin, lutein and zeaxanthin

<p>Abstract</p> <p>Background</p> <p>Age-related macular degeneration (AMD) is a disease with multiple risk factors, many of which appear to involve oxidative stress. Macular pigment, with its antioxidant and light-screening properties, is thought to be protective against AMD. A result has been the appearance of dietary supplements containing the macular carotenoids, lutein and zeaxanthin. More recently, a supplement has been marketed containing, in addition, the third major carotenoid of the macular pigment, meso-zeaxanthin. The purpose of the study was to determine the effectiveness of such a supplement in raising macular pigment density in human subjects.</p> <p>Methods</p> <p>A 120 day supplementation study was conducted in which 10 subjects were given gel-caps that provided 20 mg/day of predominantly meso-zeaxanthin, with smaller amounts of lutein and zeaxanthin. A second group of 9 subjects were given gel caps containing a placebo for the same 120 day period. Prior to and during the supplementation period, blood serum samples were analyzed by high performance liquid chromatography for carotenoid content. Similarly, macular pigment optical density was measured by heterochromatic flicker photometry. Differences in response between the supplementation and placebo groups were tested for significance using a student's t-test.</p> <p>Results</p> <p>During supplementation with the carotenoids, blood samples revealed the presence of all three carotenoids. Macular pigment optical density, measured at 460 nm, rose at an average rate of 0.59 ± 0.79 milli-absorbance unit/day in the 10 supplemented subjects. This was significantly different from the placebo group (9 subjects) for whom the average rate was -0.17 ± 0.42 milli-absorbance units/day.</p> <p>Conclusion</p> <p>We have shown for the first time that meso-zeaxanthin is absorbed into the serum following ingestion. The data indicate that a supplement containing predominantly meso-zeaxanthin is generally effective at raising macular pigment density, and may turn out to be a useful addition to the defenses against AMD.</p

A method of photometric data extraction for asteroids from time-domain surveys

The lightcurves of asteroids are essential for determining their physical characteristics, including shape, spin, size, and surface composition. However, most asteroids are missing some of these basic physical parameters due to lack of photometric data. Although a few telescopes or surveys are specially designed for photometric lightcurve observations of asteroids, many ground-based and space-based sky surveys for hunting new exoplanets, transient events, etc., should capture numerous small Solar system objects. This will benefit the physical studies of these objects. In order to extract data of these moving objects from time-domain photometric surveys, we have developed a new method using the model tree algorithm in the field of machine learning. A dedicated module is built to automatically identify moving objects in data set and extract their photometric and astrometric data. As the first application of this novel method, we have analysed data in five fields of the Yunnan-Hong Kong wide field photometric (YNHK) survey, from which 538 lightcurves of 211 asteroids are successfully extracted. Meanwhile, we also tested the method based on the data from NASA's Transiting Exoplanet Survey Satellite, and the result proves the reliability of our method. With derived lightcurves of 13 asteroids from the YNHK survey, we have determined their synodic spin periods, among which the periods of four asteroids are estimated for the first time. In future, we are going to apply this method to search for small objects in the outer part of the Solar system from the Chinese Space Station Telescope survey.Peer reviewe