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Background: Chelating agents, such as small peptides, can decrease free iron content and increase iron bioavailability. They may have promising therapeutic potential and may prevent the pro-oxidant effects of low molecular weight iron. Hairtail is a species of fish that is rich in easily digestible proteins. We extended this strategy for iron delivery by using an enzymatic hydrolysate of hairtail as the chelating agent and found that the ferrous-chelating hairtail peptides have anti-anaemic activity in Sprague-Dawley rats with anaemia., Results: The anti-anaemic activity of ferrous-chelating hairtail peptides prepared by enzymatic hydrolysis of the hairtail and ferrous chelation was studied in rat models of iron deficiency anaemia. After the end of the 35 d experiment, we noted significant differences in haemoglobin, mean corpuscular volume, haemoglobin distribution width, and ferritin concentrations between those animals supplemented with ferrous-chelating hairtail peptides and FeSO4 and healthy animals. There were no negative side effects on the animals' growth or behaviour. There was no obvious inflammation in the intestinal mucosa lamina propria and no unbalance of intestinal flora., Conclusion: The novel ferrous-chelating hairtail peptides may be a suitable fortificant for improving iron-deficiency status. Our findings demonstrated that this multi-tracer technique has many applications in nutritional research. © 2015 Society of Chemical Industry., (© 2015 Society of Chemical Industry.)

Five types of low-value fish protein hydrolysates ( FPH) and ferrous-chelating peptides [ Fe( II)- FPH] were prepared from Pacific mackerel, Spanish mackerel, hairtail, Japanese anchovy and horse mackerel. The hydrolysis degrees of FPH and ferrous chelation percentages of all types Fe( II)- FPH were calculated. The antioxidant activities were measured using 2,2-diphenyl-1-picryl-hydrazyl ( DPPH)-scavenging activity and hydroxyl radical-scavenging activity. All FPH samples demonstrated low antioxidant activity. After ferrous chelation, the DPPH-scavenging activities of Spanish mackerel- Fe( II)- FPH and hairtail- Fe( II)- FPH were significantly higher ( P < 0.05 and P < 0.01, respectively) than other FPH, and the hydroxyl radical-scavenging activity of hairtail- Fe( II)- FPH was significantly higher ( P < 0.05) than that of hairtail- FPH. Among all the tested, hairtail - Fe( II)- FPH showed the highest ferrous chelation percentage and antioxidant activity. The ferrous-chelating peptide fractions recovered from low-value fish, especially small, low-value hairtail, can be used as a source of natural antioxidants for food products. Practical Applications Efficient utilization of low-value fish is important for the economic viability of the aquatic food industry. Enzymatic hydrolysis and modification by trace metals, such as ferrous ion, is one of the most effective technologies for recovering value-added proteins from low-value fish without losing their nutritional value. In this study, five types of low-value fish were hydrolyzed by alcalase and modified by ferrous chloride. 2,2-Diphenyl-1-picryl-hydrazyl and hydroxyl radical-scavenging activities were studied. The potential antioxidant activities of ferrous-chelating peptide fractions recovered from low-value fish, especially hairtail, can be used in a wide range of food additives, diet nutrients and pharmaceutical agents. [ABSTRACT FROM AUTHOR]

Ramoplanin is a lipopeptide antibiotic active against multi-drug-resistant, Gram-positive pathogens. Structurally, it contains a di-mannose moiety attached to the peptide core at Hpg. The biosynthetic gene cluster of ramoplanin has already been reported and the assembly of the depsipeptide has been elucidated but the mechanism of transferring sugar moiety to the peptide core remains unclear. Sequence analysis of the biosynthetic gene cluster indicated ramo- orf29 was a mannosyltransferase candidate. To investigate the involvement of ramo- orf29 in ramoplanin biosynthesis, gene inactivation and complementation have been conducted in Actinoplanes sp. ATCC 33076 by homologous recombination. Metabolite analysis revealed that the ramo- orf29 inactivated mutant produced no ramoplanin but the ramoplanin aglycone. Thus, ramo- orf29 codes for the mannosyltransferase in the ramoplanin biosynthesis pathway. This lays the foundation for further exploitation of the ramoplanin mannosyltransferase and aglycone in combinatorial biosynthesis. [ABSTRACT FROM AUTHOR]

The present experiment was conducted to investigate the effects of prepared hairtail ( Lepidopusc audatus ) hydrolysis peptide–metal element (Fe 2 + , Zn 2 + , Ca 2 + , or Mg 2 + ) complexes (PH–Fe 2 + , PH–Zn 2 + , PH–Ca 2 + , or PH–Mg 2 + ) on the depuration of cadmium (Cd) from blue mussel ( Mytilus edulis ) tissues. Cd concentrations in anterior adductor muscle, posterior adductor muscle, gill, mantle, and visceral mass of mussels were 11.391, 15.323, 63.672, 19.509, and 109.621 μg/g, respectively, after 5 days of exposure to 0.32 mg/L Cd. Five groups of these exposed mussels were then exposed to seawater laced with four different concentrations of the peptide complexes listed above (5, 10, 15, and 20 mg/L) for 8 days. After 8 days of depuration, 5 mg/L of PH–Fe 2 + , PH–Zn 2 + , and PH–Ca 2 + showed no significant ( P > 0.05) effects on Cd concentrations in mussel tissues. However, significant differences ( P < 0.05) were observed in groups exposed to 20 mg/L of PH–Fe 2 + , PH–Zn 2 + , and PH–Ca 2 + . The Cd concentrations in anterior adductor muscle, posterior adductor muscle, gill, mantle, and visceral mass were significantly ( P < 0.05) decreased by 29.56–35.83%, 27.51–33.62%, 31.59–40.34%, 25.83–31.28%, and 33.62–33.97%, respectively. Nevertheless, the variables of Cd concentrations in tissues treated with 5–20 mg/L PH–Mg 2 + showed no significant ( P > 0.05) differences from controls at any point during the experimental period. For these reasons, PH–Fe 2 + , PH–Zn 2 + , and PH–Ca 2 + can be recommended as depuration agents in mussel feed to decrease the Cd concentrations in tissues. [ABSTRACT FROM AUTHOR]