ABSTRACT
Astaxanthin is a kind of important carotenoids with powerful antioxidation capacity and other health functions. Extracting from Adonis amurensis is a promising way to obtain natural astaxanthin. However, how to ensure the high purity and to investigate related substances in astaxanthin crystals are necessary issues. In this study, to identify possible impurities, astaxanthin crystal was first extracted from Adonis amurensis, then purified by saponification and separation. The concentration of total carotenoids in purified astaxanthin crystals was as high as 97% by weight when analyzed by UV-visible absorption spectra. After identified with TLC, HPLC and MS, besides free astaxanthin as main ingredient in the crystals, there existed four other unknown related substances, which were further investigated by HPLC/ESI/MS with the positive ion mode combining with other auxiliary reference data obtained in stress tests, at last it was confirmed that four related carotenoids substances were three structural isomers of semi-astacene and adonirubin.
Subject(s)
Adonis/chemistry , Antioxidants , Carotenoids/analysis , Canthaxanthin/analogs & derivatives , Canthaxanthin/analysis , Canthaxanthin/chemistry , Carotenoids/chemistry , Chromatography, High Pressure Liquid , Chromatography, Thin Layer , Crystallization , Isomerism , Mass Spectrometry , Spectrum Analysis/methods , Xanthophylls/chemistry , Xanthophylls/isolation & purificationABSTRACT
BACKGROUND: The effects of intermittent, high dose vitamin D treatment in older adults have not been documented. We conducted a meta-analysis to provide a quantitative assessment of the efficiency of intermittent, high dose vitamin D treatment on falls, fractures, and mortality among older adults. METHODS: Electronic databases were searched for randomized controlled trials (RCTs) on high dose, intermittent vitamin D supplementation among older adults. Two researchers independently screened the literature according to specified inclusive and exclusive criteria to extract the data. Meta-analysis was performed by using Review Manager 5.1.0 software. RESULTS: Nine trials were included in this meta-analysis. High dose, intermittent vitamin D therapy did not decrease all-cause mortality among older adults. The risk ratio (95% CI) was 1.04 (0.91-1.17). No benefit was seen in fracture or fall prevention. The risk ratio for hip fractures (95% CI) was 1.17 (0.97-1.41) while for non-vertebral fractures (95% CI) it was 1.06 (0.91-1.22), and the risk ratio for falls (95% CI) was 1.02 (0.96-1.08). Results remained robust after sensitivity analysis. CONCLUSION: Supplementation of intermittent, high dose vitamin D may not be effective in preventing overall mortality, fractures, or falls among older adults. The route of administration of vitamin D supplements may well change the physiological effects.
