Search

This work reported the application of a twin‐column recycling chromatography system for the separation of three minor impurities in crude aloe‐emodin. The whole process went through three steps, each using a different mobile phase to separate corresponding impurity, which were integrated and automatically operated in a single device. Despite these impurities peaked closely in high‐performance liquid chromatography, they were successfully purified to a content exceeding 97%. In addition, the lab‐scale separation could reach the yields at the mg‐level. The high efficacy should be mainly attributed to the introduction of a small step solvent gradient between the upstream and downstream columns, which helped to counterbalance the band broadening. This report suggested that such an automated chromatographic system could provide fast and accurate separation of multiple impurities, allow the process of high‐throughput samples, and reduce the time required for purification and recovery of minor impurities in drugs. [ABSTRACT FROM AUTHOR]

ABSTRACT Protein hydrolysates were prepared from Bombay duck ( Harpodon nehereus) by the combination of commercially available papain and Flavourzyme (Novozymes, Copenhagen, Denmark) . The influences of hydrolysis time and enzymes substrate ratio on the degree of hydrolysis (DH) were investigated in detail. Hydrolysates were freeze-dried and the obtained powder was characterized with respect to yield, moisture, nitrogen recovery, amino acid composition and peptide molecular mass distribution. The mechanism of reducing bitterness of hydrolysates was also studied. A DH of up to 19.7% was obtained under the optimal hydrolysis conditions. The mass yield, nitrogen recovery and moisture of freeze-dried fish protein hydrolysates were 10.5 g/100 g wet weight of raw material, 87.5% and 4.2%, respectively. The molecular mass of hydrolysates determined by size-exclusion chromatography was between 219 and 5,245 Da. The oligopeptides were the main fraction of the hydrolysates. It was significant that L-leucine was removed from oligopeptides to reduce the bitterness of hydrolysates. PRACTICAL APPLICATION Bombay duck ( Harpodon nehereus) has high a nutrition value, with a protein content of up to 70% of dry mass. There is a great interest in utilizing the proteins of this fish efficiently on industrial scale. The hydrolysates of the fish protein were prepared by enzymatic hydrolysis and dry-freezing. The characteristics of hydrolysates were determined to predict their potential as a nutritious supplement in various food products. Low molecular peptides were the main composition of the hydrolysates, which possess health properties and promote food products supplemented by hydrolysates as healthy and nutritious. [ABSTRACT FROM AUTHOR]