皱瘤海鞘被囊多肽的抗氧化活性

摘要

为了评估水产养殖的污损生物—海鞘的生物利用价值,研究南海海鞘优势种—皱瘤海鞘(Styela plicata)被囊多肽的体外抗氧化活性,探索不同分子量级的被囊多肽对DPPH·以及O2-·清除能力.试验经提取、超滤得4种分子量级的被囊多肽,通过其对DPPH·以及O2-·的清除率来比较4种分子量级被囊多肽的抗氧化活性.结果表明:相对分子质量小于3 KD的皱瘤海鞘被囊多肽抗氧化活性最好,其中2.5g·L-1浓度对于DPPH·清除率达到(42.97 ±1.05)％,对于O2-·清除率达到(33.50±0.28)％.3～10,10 ～ 30 KD的被囊多肽抗氧化活性接近,对于DPPH·以及O2-·的清除率都在22％ ～ 24％之间.大于30 KD的被囊多肽对于2种白由基的清除率相对最低,平均分别为18.34％(DPPH·)和17.88％(O2-·).4种分子量级的皱瘤海鞘被囊多肽在0.5 ～2.5 g·L-1浓度范围内都具有良好的抗氧化活性,具有进一步开发为化妆品添加成分及抗衰老保健品的潜力.%To evaluate the biological value of fouling organism,sea squirt,in marine aquaculture,Styela plicata,a dominant sea squirt species in the South China Sea,was collected fresh to prepare polypeptides from their tunic by extraction,and the extracted polypeptides were used to evaluate their capacities to scavenge free radicals DPPH and O2-for analysis of the in-vitro antioxidative activity of the polypeptides of different molecular weights.Tunic polypeptides of four molecular weights were prepared by extraction and uhrafiltration,and their antioxidative activities were compared in scavenging of the free radicals DPPH and O2-The results showed that the ＜ 3 KD polypeptides had the highest antioxidative activity,of which the free radical scavenging rates of the polypeptides at the concentration of 2.5 g · L-1 were (42.97 ± 1.05) ％ for DPPH and (33.50 ± 0.28) ％ for O2-· The 3-10 KD polypeptides had a very similar antioxidative activity to the 10-30 KD polypeptides,and their scavenging rates for the free radicals DPPH and O2-were between 22％ and 24％.The ＞ 30 KD polypeptides had the lowest free radical scavenging rates:18.34％ for DPPH and 17.88％ for O2-These results indicated that the polypeptides of four molecular weights extracted from Styela plicata tunic manifested good antioxidative activity when their concentrations ranged from 0.5 to 2.5 g · L-1,which suggests a potential to use these polypeptides to further develop ingredients for cosmetics and anti-aging health products.