Antioxidant Assessment of Schizochytrium Meal Protein Enzymatic Hydrolysate and Its Potential Application

Schizochytrium meal protein (SMP) extracted from Schizochytrium meal was hydrolyzed by flavourzyme. Response surface methodology (RSM) was used to optimize the extraction conditions for the protein extraction yield from Schizochytrium meal. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (DRSA) was used to evaluate the antioxidant activity of hydrolysates. The orthogonal test was used to investigate the effects of three independent variables, namely protease dosage, hydrolysis time, and pH. The optimum conditions obtained were as follows: protease dosage of 7%, hydrolysis time of 1.5 h, pH of 6, under which, DRSA at the concentration of 2 mg/mL was 89.38%. Aspartic and glutamic acid constituted approximately 26.32% of the total amino acids, and glutamic acid was the most abundant amino acid of Schizochytrium meal protein hydrolysate (SMPH) by amino acid composition analysis, which may have contributed to the scavenging activity of SMPH. Moreover, SMPH was made into chewable tablets with suitable formula and high humidity stability. These findings indicate that Schizochytrium meal can be reused as a raw material for preparation of antioxidant peptides.     

安徽省一些用材树种鲜叶提取物清除DPPH自由基的活性初探

用二苯基苦基苯肼自由基酶标仪法,对亚热带常见的130余种用材树种鲜叶80%甲醇提取物的自由基清除活性进行了比较,发现所有树种的80%甲醇提取物的自由基清除率都随浓度的增加和37℃下孵育时间的延长而增大.其中,黄连木、毛果槭、三角槭、枫香、黄山栾树、苦木、麻栎、秀丽槭、青榨槭、山杜英、青冈栎、始建槭、米心水青冈、乌桕、栾树和黄山花楸等树种的清除自由基活性最强,它们在相当原鲜叶浓度为0.5mg·mL-1于37℃孵育20 min后,对0.5 mmol·L-3DPPH自由基的清除率分别达90.6%、89.0%、86.4%、85.7%、84.0%、79.3%、77.6%、77.1%、75.6%、71.5%、70.7%、69.0%、68.7%、63.8%、62.0%和61.3%.结果显示这些树种具有较大的开发潜力.     

诃子抗氧化活性的研究

对诃子与龙井茶和银杏叶的抗氧化活性进行了比较,并对其抗氧化活性进行了研究.结果显示诃子提取物总多酚含量为(211.229±8.236)mg/g、总黄酮含量为(49.509±1.362)mg/g,高含量的总多酚是其强抗氧化活性的主要物质基础.诃子粗提物抗氧化活性显著高于阳性对照BHT;采用不同极性溶剂对诃子粗提物进行萃取后发现乙酸乙酯萃取相抗氧化活性最强.     

牛筋果脂溶性成分及其抗氧化活性的研究

应用气相色谱一质谱联用技术（GC—MS）对牛筋果[Harrisonia perforata （（Blanco）Merrill）]果实的石油醚萃取部分脂溶性成分进行了初步研究。结果显示。石油醚萃取部分共鉴定了29种脂溶性成分,占总峰面积的69．67％．并确定其相对含量：其中含量较高的成分依次是顺-9,12-十八碳二烯醇（12．35％）、棕榈酸（9．67％）、于9,17-十八碳烯醛（8．97％）、亚油酸（7．97％）、油酸乙酯（5．81％）、伊谷甾醇（4．88％）、亚油酸乙酯（4．10％）。在此基础上．采用清除DPPH自由基能力的方法测定了醇提物、乙酸乙酯萃取物及石油醚萃取物的抗氧化活性,结果均显示出较强的抗氧化活性,其IC50值分别为40、22和288μg／mL,由于石油醚萃取物的抗氧化活性远远大于其它萃取物．因此笔者等先行对其进行了研究。     

不同采收期三白草中总黄酮含量测定及抗氧化活性研究

目的测定不同采收期三白草中总黄酮含量及其抗氧化活性,方法采用AlCl3比色法测定总黄酮含量,通过DPPH自由基(DPPH·)法和测定还原Fe3+能力的方法评价其抗氧化能力。结果芦丁在0.01～0.1mg/mL范围内呈良好的线性关系,平均回收率为99.62%,RSD为2.37%,5月和8月份采收三白草中总黄酮含量较高,分别为67.56和44.61mg/g,同时清除DPPH·活性亦较强,IC50分别为2.35和2.57mg/mL。结论不同采收期三白草中总黄酮含量和抗氧化活性较大差异,为三白草采收及开发利用提供了一定的科学依据。     

Chemical profiling and biological screening of Thymus lotocephalus extracts obtained by supercritical fluid extraction and hydrodistillation

Essential oil and extracts from the aerial parts of Thymus lotocephalus were obtained by hydrodistillation (HD) and supercritical fluid extraction (SFE) in two different collectors, respectively. SFE was conducted at 40 °C and a working pressure of 12 or 18 MPa. The chemical profiles were determined using GC-FID and GC-IT-MS. Oxygen-containing monoterpenes were the primary constituents in the essential oil and SFE extracts collected in the second separator, while the extracts obtained in the first separator were predominantly oxygen-containing sesquiterpenes. A large number of compounds were identified by hydrodistillation and, in contrast, the highest extraction yields were obtained using SFE. Linalool (10.43 ± 1.63%) was the main component in essential oil, whereas camphor (7.91 ± 0.84%) and cis-linalool oxide (7.25 ± 1.45%) were the major compounds in the extracts-2nd separator obtained at pressures of 12 and 18 MPa, respectively. Caryophyllene oxide was the primary constituent identified in the extracts-1st separator (4.34 ± 0.51 and 4.41 ± 1.25% obtained at 12 and 18 MPa, respectively). The antioxidant activity was assessed by ORAC and DPPH assays, and the anti-cholinesterase activity was evaluated in vitro using Ellman's method. The essential oil and SFE extracts (first separator) of T. lotocephalus possessed antioxidant activity and strongly inhibited cholinesterases. We also demonstrated that the acetylcholinesterase and butyrylcholinesterase inhibitory activities of the essential oil could be attributed to 1,8-cineole and caryophyllene oxide, respectively.     

Chemical composition of the essential oil and antioxidant activity of methanolic extracts from fruits and flowers of Hypericum lydium Boiss.

This study was conducted to evaluate the essential oil composition and antioxidant activity of methanolic extracts from fruits and flowers of Hypericum lydium Boiss., a wild growing species of the Turkish flora. The antioxidant activities were determined through several biochemical assays. Both extracts showed an inhibitory effect against the formation of TBARS in a phosphatidylcholine liposome model system, moderate scavenging effect on DPPH and superoxide radicals, prominent reducing power and inhibitory effect on deoxyribose degradation in both the nonsite and site-specific assay, but a greater hydroxyl radical scavenging activity was observed in the non-site specific assay, suggesting that the extracts were better at scavenging hydroxyl radicals than at chelating iron. Correlation analysis indicated that there was a linear relationship between antioxidant potency, free-radical scavenging activity, reducing power and the content of flavonoids of fruits and flowers extracts. The essential oils obtained by hydrodistillation were analyzed by GC and GC-MS. In total forty-three compounds were identified. The most abundant components were monoterpenes hydrocarbons represented principally by α-pinene. The tested oil showed no antioxidant activity.     

从桑枝皮醇提物萃取的不同组分及其体外生物活性

为了从桑枝皮中获取有效的药用功能性成分,以不同极性的有机溶剂石油醚、氯仿、乙酸乙酯、正丁醇进一步萃取并分离桑枝皮醇提物(MBBEE)中的活性成分,获得的正丁醇萃取组分(n-BuOH)和剩余水相组分(Res)占MBBEE总量的94.26%(其中Res组分得率达73.72%,n-BuOH组分得率为20.54%),石油醚、氯仿、乙酸乙酯3种萃取组分的得率总共不足2%。对各种样品的活性成分检测表明,MBBEE中含有的总黄酮、总多酚和总糖3种活性成分分别为39.99、56.24和16.37mg/g,而以上3种活性成分在n-BuOH组分中分别为74.25、107.49和14.21mg/g,在Res组分中分别为262.16、118.70和75.88mg/g。对各种样品的氨基酸组成分析表明,游离氨基酸含量为n-BuOH组分>MBBEE>Res组分。各种样品的体外生物活性试验显示,MBBEE、n-BuOH组分和Res组分均具有很强的DPPH自由基清除作用以及对酪氨酸酶和α-葡萄糖苷酶的抑制作用,其中:对DPPH自由基清除作用以Res组分最强,抑制中值(IC50)为100μg/mL;对酪氨酸酶抑制活性以n-BuOH组分最高,IC50为5.2μg/mL;对α-葡萄糖苷酶的抑制活性以Res组分最高,IC50为2.8μg/mL。试验结果表明,从桑枝皮醇提物中萃取的n-BuOH组分和Res组分是降血糖以及抗氧化、抗衰老、美白的功能性成分。     

刺老芽根提取物对DPPH自由基的清除能力及抑菌作用

[目的]研究刺老芽根提取物对DPPH自由基的清除能力及抑菌效果。[方法]选择不同树龄的刺老芽根皮,通过95%乙醇反复浸泡提取其有效成分,计算各个样品的提取效率。采用DPPH自由基清除法测定各提取物的体外抗氧化活性和采用体外抑菌试验法测定对大肠杆菌、沙门氏菌、嗜水气单胞菌、金黄色葡萄球菌的体外抑菌效果.[结果]各个样品的提取效率分别为29.68%、32.23%、23.5%和19.26%。抑菌试验只对金黄色葡萄球菌有抑菌效果,抑菌直径在10～14mm。其中抑菌作用最强的4年生根提取物的最小抑菌浓度（MIC）为250mg/ml。各个样品在10mg/ml时体外DPPH自由基清除率分别为81.9%,75.57%,91.9%和89.66%。5年和6年生根皮提取物高于同浓度的阳性对照物维生素C的效应。[结论]刺老芽根具有良好的开发前景。