活性玉米醇溶蛋白肽的分离纯化及其还原活性研究

碱性蛋白酶水解玉米醇溶蛋白,精制后的水解产物为玉米醇溶蛋白肽。根据玉米醇溶蛋白肽对邻苯三酚自氧化的抑制活性,采用葡聚糖凝胶层析法及高效液相层析(HPLC)法分离纯化得到活性蛋白肽的几种组分,探讨了几种组分对超氧阴离子自由基的清除活性。同时,以α-生育酚为阳性对照,探讨了活性蛋白肽及其各组分的还原力。结果表明,经SephedaxG-10葡聚糖凝胶层析分离所得组分4的抗氧化活性最强,具有较高的还原力;组分4富含谷氨酸、丙氨酸、亮氨酸、组氨酸、脯氨酸和苯丙氨酸。     

合浦珠母贝肉短肽的分离及其抗氧化活性研究

为制备具有抗氧化能力的合浦珠母贝肉活性肽,本文采用Sephadex G-25分子筛层析法对合浦珠母贝肉酶解产物进行分离,测定分离到的各活性组分分子量及其总抗氧化活性、DPPH自由基清除能力及羟自由基清除能力。结果表明,合浦珠母贝肉酶解产物经Sephadex G-25分离得到6个主要活性组分,相对分子量分别为1437.5、833.7、421.9、244.7、89.0、17.4u,其中功能短肽F1(1437.5u)、F2(833.7u)、F4(244.7u)的抗氧化效果较强,特别是F2(833.7u)短肽具有最强的总抗氧化能力、DPPH自由基清除能力及羟自由基清除能力。该研究为合浦珠母贝肉抗氧化活性肽的开发提供理论技术依据。     

干酪乳清水解产物的抗氧化活性研究

选用新鲜干酪乳清为原料,研究碱性蛋白酶对乳清水解产物的抗氧化活性。以水解产物的亚铁还原能力、对卵磷脂脂质氧化体系的过氧化抑制作用、羟自由基清除能力和超氧阴离子自由基的清除能力为指标评价乳清水解产物的抗氧化能力。结果表明,乳清在水解前经过预热处理并不能增加其水解产物的抗氧化活性,1 h水解物的亚铁还原能力最高,2 h水解产物对卵磷脂脂质氧化体系的过氧化抑制作用最高,抑制率达到24.82%;2 h水解产物羟自由基清除率最高,达到70.28%;2 h水解产物超氧阴离子自由基清除率最高,达到21.4%。但是乳清水解产物的抗氧化能力与水解度没有线性关系。     

黑蚂蚁蛋白的酶解优化及抗氧化肽的超滤膜分离

本文研究了酶量、温度、pH和时间四个因素对黑蚂蚁蛋白的碱性酶法水解的影响。通过响应面设计,以各个抗氧化活性为指标,优化了超氧自由基清除率,DPPH自由基清除率,羟基自由基清除率,还原力和亚油酸自氧化抑制作用最强的酶解工艺条件。验证实验证实方程的准确率达95%以上。采用超滤膜及离子交换色谱对酶解产物进行了分离,发现5-10 kDa和1-3 kDa组分的抗氧化能力最强,碱性肽对超氧自由基清除能力、羟基自由基清除能力、亚油酸自氧化抑制作用贡献较大,酸性肽对DPPH自由基清除能力及还原力的贡献较大。     

苦丁茶多糖抗氧化活性研究

采用清除超氧阴离子自由基、清除羟自由基、清除DPPH自由基、双氧水诱导红细胞氧化溶血、红细胞自氧化溶血实验,对A、K_1、K_3三个苦丁茶多糖组分的抗氧化活性进行了研究,并与Vc进行了比较,结果表明:苦丁茶多糖对羟自由基、超氧阴离子自由基、DPPH自由基具有一定的清除作用;对H_2O_2诱导红细胞氧化溶血反应、对红细胞自氧化溶血反应都有显著的抑制作用。     

萌芽黑豆中蛋白质组分分子量分布及其抗氧化活性研究

本文目的是研究萌芽黑豆中不同蛋白质组分的分子量分布,以及各组分的抗氧化活性。采用碱提酸沉法获得萌芽黑豆中的蛋白质,通过硫酸铵盐析法逐级分离各蛋白质组分,SDS-PAGE法测定各蛋白质组分分子量分布,并从清除自由基和抗人皮肤成纤维细胞氧化损伤两个方面研究了各蛋白质组分的抗氧化活性。萌芽黑豆中蛋白质组分可以集中分离为三个部分,其分子量分布为140.0~166.0、45.0~72.0、17.0~23.0ku;清除自由基和抗人皮肤成纤维细胞氧化损伤的实验结果均表明分子量在17.0~23.0ku的蛋白质组分具有最优的抗氧化活性,说明低分子量的萌芽黑豆蛋白质具有更强的抗氧化活性。     

几种南海贝类酶解产物的生物活性及其分子量分布研究

对菲律宾蛤仔、波纹巴非蛤、马氏珠母贝双酶水解产物的自由基清除活性和血管紧张素转化酶（ACE）抑制活性及分子量分布进行研究。结果表明：3种贝类酶解产物均具有清除羟自由基、超氧阴离子、二苯基苦基苯肼（DPPH）等自由基的活性以及ACE抑制活性;3种贝类酶解产物对超氧阴离子的清除作用均较弱;羟自由基清除活性较强的是菲律宾蛤仔酶解产物,其高活性组分的分子量在1479～851 Da之间;DPPH自由基清除活性较强的是菲律宾蛤仔酶解产物,其高活性组分的分子量在1479～851 Da之间;ACE抑制活性较强的是波纹巴非蛤酶解产物,其高活性组分的分子量在633—303 Da之间。     

鲨鱼皮明胶水解肽的制备、分离纯化与抗氧化活性研究

目的:基于鲨鱼皮明胶水解肽的抗氧化活性,制备、分离纯化高活性的抗氧化多肽。方法:分别使用5种商业蛋白酶水解鲨鱼皮明胶,测定其水解产物的DPPH自由基清除能力、ABTS自由基清除活性以及对Fe2+诱导卵黄脂蛋白多不饱和脂肪酸过氧化反应的抑制作用;利用SP-Sephadex C-25阳离子交换色谱、Sephadex G-50凝胶过滤色谱和C18反向高效液相色谱(HPLC)对酸性蛋白酶的水解产物进行分离纯化。结果:酸性蛋白酶水解产物具有最佳的抗氧化活性;利用SP-Sephadex C-25、Sephadex G-50和C18-HPLC对酸性蛋白酶的水解产物进行分离纯化,所得洗脱组分E2具有最强的清除DPPH自由基活性。经过ESI质谱分析,其多肽组分的主要分子质量为1356u。结论:本研究制备并分离纯化得到高活性的抗氧化多肽,为将来的生产应用提供理论依据。     

芸豆肽的抗氧化活性研究

采用Sephadex-G50 凝胶柱层析分离具有强抗氧化活性的小分子芸豆肽,以VC 为对照,研究3 种肽分离组分的还原能力及对羟自由基、超氧阴离子自由基和DPPH 自由基的清除能力。结果表明：随着相对分子质量的减小和肽质量浓度的增加,其还原能力及对羟自由基、超氧阴离子自由基和DPPH 自由基的清除能力逐渐增大;小分子芸豆肽(C 组分)的还原能力低于VC;对羟自由基、超氧阴离子自由基和DPPH 自由基的半清除质量浓度分别为2.301、2.553、1.386mg/mL。该小分子肽组分的相对分子质量主要集中在100～1000,该组分疏水性氨基酸含量为36.78%,其疏水值达到364.73 kcal/mol。说明小分子肽组分的抗氧化活性与其氨基酸种类和组成、相对分子质量分布密切相关。     

超高压与Alcalase协同作用制备牛乳清蛋白抗氧化肽

为探讨超高压与碱性蛋白酶Alcalase协同作用下乳清蛋白抗氧化肽的制备,以牛乳清分离蛋白(WPI)为原料,采用Alcalase分别对100～600MPa的超高压处理中和超高压处理后的WPI进行水解,并采用邻苯三酚自氧化法对其水解产物的超氧阴离子自由基清除能力进行测定。结果表明,超高压与Alcalase协同作用显著地促进了WPI的水解,其水解产物的抗氧化活性也显著提高;分子量小于3ku的组分具有最强的超氧阴离子自由基清除能力,其半抑制浓度IC50值最小,为411.62μg/mL。因此,超高压与Alcalase协同作用于乳清蛋白可用于开发新型天然抗氧化剂。     

驴乳的营养成分及其保健作用的研究进展

驴乳作为营养品广泛使用已有数千年的历史,因其含有多种营养成分和生物活性,是婴幼儿、老年及体弱者补充营养物质的重要来源。该文综述驴乳的营养成分和抗菌、抗炎、抗氧化、抗过敏等保健作用,以期为驴乳产业提供新的方向和理论支持。     

The effect of in vitro gastrointestinal simulation on bioactivities of kefir

Kefir is a fermented milk beverage and known to have positive effects on gut microbial diversity and human health. In this study, digested and undigested kefir samples were compared for changes in their antihypertensive, antidiabetic, antioxidant and antimicrobial activities. Results showed that the amount of total phenolic substances, 2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH) activity, and the angiotensin-converting enzyme inhibitor (ACE-I) activity increased from 43.76 ± 0.005 mg gallic acid equivalents (GAE)/L, 4.20 ± 0.55%, and 9.91 ± 3.90% in undigested kefir to 668.16 ± 3.332 mg GAE/L, 63.06 ± 0.64%, and 98.88 ± 0.42% in digested kefir, respectively. While the dipeptidyl peptidase IV-inhibitory (DPPIV-I) activity of undigested kefir increased by 19.11 ± 7.35% after digestion, the optical density of the ferric-reducing antioxidant power (FRAP) decreased from 1.188 ± 0.05 to 0.278 ± 0.009, and the protein amount decreased from 101.4 mg L⁻¹ to 12.42 mg L⁻¹ in digested kefir. No antimicrobial effect was observed in undigested kefir, whereas, digested kefir samples were active, but only against Escherichia coli. These results show that the gastrointestinal digestion processes of kefir generally increase the number of bioactive molecules, and the digestion process must be taken into account to determine the biological capability of foods.     

Cladonia lichens and their major metabolites as possible natural antioxidant,antimicrobial and anticancer agents

The aim of this study is to investigate in vitro antioxidant, antimicrobial, and anticancer activities of the acetone extracts of the lichens Cladonia furcata, Cladonia pyxidata and Cladonia rangiferina and their atranorin and fumarprotocetraric acid constituents. Antioxidant activity was evaluated by free radical scavenging, superoxide anion radical scavenging, reducing power, and determination of total phenolic and flavonoid compounds. As a result of the study atranorin had largest free radical scavenging activity with IC₅₀ values 131.48 μg/mL. Moreover, the tested samples had effective reducing power and superoxide anion radical scavenging. Total content of phenol and flavonoid in extracts was determined as pyrocatechol equivalent, and as rutin equivalent, respectively. The strong relationships between total phenolic and flavonoid contents and the antioxidant effect of tested extracts were observed. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method. The most active was fumarprotocetraric acid with minimum inhibitory concentration values ranging from 0.031 to 0.125 mg/mL. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using MTT method. All samples were found to be strong anticancer activity toward both cell lines with IC₅₀ values ranging from 10.97 to 41.23 μg/mL.     

Antioxidant, antimicrobial, and anticancer activity of 3 Umbilicaria species

Abstract: The aim of this study is to investigate in vitro antioxidant, antimicrobial, and anticancer activity of the acetone extracts of the lichens Umbilicaria crustulosa, U. cylindrica, and U. polyphylla. Antioxidant activity was evaluated by 5 separate methods: free radical scavenging, superoxide anion radical scavenging, reducing power, determination of total phenolic compounds, and determination of total flavonoid content. Of the lichens tested, U. polyphylla had largest free radical scavenging activity (72.79% inhibition at a concentration of 1 mg/mL), which was similar as standard antioxidants in the same concentration. Moreover, the tested extracts had effective reducing power and superoxide anion radical scavenging. Total content of phenol and flavonoid in extracts was determined as pyrocatechol equivalent, and as rutin equivalent, respectively. The strong relationships between total phenolic and flavonoid contents and the antioxidant effect of tested extracts were observed. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method. The most active was extract of U. polyphylla with minimum inhibitory concentration values ranging from 1.56 to 12.5 mg/mL. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using MTT method. All extracts were found to be strong anticancer activity toward both cell lines with IC₅₀ values ranging from 28.45 to 97.82 μg/mL. The present study shows that tested lichen extracts demonstrated a strong antioxidant, antimicrobial, and anticancer effects. That suggests that lichens may be used as possible natural antioxidant, antimicrobial, and anticancer agents.     

Antioxidant, antimicrobial and anticancer activities of three Parmelia species

BACKGROUND: Lichens are symbiotic organisms consisting of algae and fungi. They are used for human and animal nutrition and in the production of colours, perfumes and alcohol. Lichens have also been used in traditional medicine to treat diseases such as jaundice, pulmonary, stomach and cranial diseases. In this study the acetone extracts of three lichens, Parmelia caperata, Parmelia sulcata and Parmelia saxatilis, were tested for their antioxidant, antimicrobial and anticancer potential. RESULTS: Of the lichens tested, P. saxatilis had the highest free radical‐scavenging activity (55.3% inhibition). Moreover, all tested extracts showed effective reducing power and superoxide anion radical scavenging. Strong relationships between total phenolic and flavonoid contents and antioxidant effects of the tested extracts were observed. The extract of P. sulcata was most active in terms of antimicrobial ability, with minimum inhibitory concentration values ranging from 0.78 to 12.5 mg L^?1. All extracts were found to have strong anticancer activity, with IC₅₀ values ranging from 9.55 to 22.95 µg mL^?1. CONCLUSION: The present study showed that the tested lichen extracts exhibited strong antioxidant, antimicrobial and anticancer effects. This suggests that lichens may be used as possible natural antioxidant, antimicrobial and anticancer agents. Copyright © 2012 Society of Chemical Industry     

Biological activities of Maillard reaction products (MRPs) in a sugar–amino acid model system

The various biological activities of Maillard reaction products (MRPs) from sugar (fructose and glucose) and 20 amino acid model systems were evaluated. Colour development, in vitro antioxidant, α-glucosidase inhibitory, antihypertensive, and antiproliferative activities of aqueous solutions of MRPs produced by heating at 130 °C for 2 h were measured. The fructose–amino acid mixture showed higher UV-absorbance and browning intensity than the glucose–amino acid mixture. The fructose–amino acid model MRPs showed higher DPPH and ABTS radical scavenging and ACE inhibitory activities than the glucose–amino acid model MRPs. The α-glucosidase inhibitory effect of MRPs derived from fructose– and glucose–tyrosine showed higher α-glucosidase inhibitory activity than that of other MRPs. Sugar–amino acid model MRPs inhibited the growth of HCT116 colon cancer cell in a dose-dependent manner (from 0.5 to 1.5 mg/ml). Glucose MRPs showed slightly higher antiproliferative activity than fructose MRPs. In particular, sugar–tryptophan and –tyrosine MRPs exerted higher biological activities than the other MRPs.     

Antioxidant,Antibacterial, and Antiproliferative Activities of Free and Bound Phenolics from Peel and Flesh of Fuji Apple

This study was conducted to investigate the antioxidant, antibacterial, and antiproliferative activities of flesh free (FF), flesh bound (FB), peel free (PF), and peel bound (PB) phenolics from Fuji apple. The PB, which had highest total phenolic contents (126.15 ± 2.41 mg/100 g wet weight) and lowest total carbohydrate contents (34.68 ± 2.78 mg/100 g wet weight), showed the strongest 2,2’‐azinobis‐(3‐ethylbenthiazoline‐6‐sulphonate) (ABTS) radical scavenging activity (EC₅₀ = 0.36 ± 0.02 mg/mL), 1,1‐diphenyl‐2‐picryhydrazyl (DPPH) radical scavenging activity (EC₅₀ = 0.26 ± 0.01 mg/mL), and ferric reducing antioxidant power (Ferric reducing antioxidant power; EC₅₀ = 0.19 ± 0.02 mg/mL) compared with those of FF, FB, and PF. The PB also showed the strongest antibacterial activities on Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes and it also showed the highest antiproliferative effects on Caco‐2 human colonic cancer cell (EC₅₀ = 1.44 ± 0.01 mg/mL) and Hela human cervical cell (EC₅₀ = 2.81 ± 0.01 mg/mL). Both free and bound phenolics from Fuji apple showed good antioxidant, antibacterial, and antiproliferative activities in our study, and bound phenolics had significantly higher activities compared with those of free phenolics.     

浏阳豆豉发酵中高产酶活菌株的分离鉴定及酶活性分析

从浏阳豆豉发酵过程中分离产高酶活菌株,通过形态观察结合分子生物学技术进行鉴定,并对其产蛋白酶、脂肪酶及纤维素酶的活性进行分析。结果表明,分离得到3株菌（编号为000、5132、621）均被鉴定为溜曲霉菌（Aspergillus tamarri）。3株菌的蛋白酶、脂肪酶及纤维素酶的活性测定结果表明,菌株621蛋白酶活性最强,为（207.98±3.20）U/mL;菌株5132的纤维素酶活性最强,为（3.40±1.40）U/mL;菌株000的脂肪酶活性最高,为（90.7±0.64）U/mL。     

红参浓缩液对小鼠的抗氧化、免疫调节及降血糖作用

该研究通过建立衰老小鼠模型和II型糖尿病小鼠模型,对比不同剂量的红参浓缩液对小鼠体内抗氧化、免疫及降血糖活性影响。实验发现：与模型组相比,红参浓缩液给药组显著降低丙二醛含量（MDA）、空腹血糖（FBG）和口服葡萄糖耐量（OGTT）血糖曲线下面积（AUC）并且显著提高羟自由基清除率（•OH）、总超氧化物歧化酶（T-SOD）、谷胱甘肽过氧化氢酶（GSH-Px）和过氧化氢酶（CAT）活力和免疫球蛋白G（Ig G）、免疫球蛋白M（Ig M）、白细胞介素4（IL-4）和γ干扰素（IFN-γ）含量（P<0.05）,明显改善脾脏损害。以上结果表明一定浓度的红参浓缩液可以延缓衰老、提高衰老模型小鼠的免疫力,增强II型糖尿病模型小鼠的葡萄糖耐受力,具有降血糖的效果。     

Antioxidant and antimicrobial activities of propolis from several regions of Korea

Biological activities of different propolis extracts in Korea were examined for the evaluation of quality comparison with that from Brazil (BZ). Total polyphenol and flavonoid contents of propolis extracts from Yeosu (YS) and Cheorwon (CW), whose values were higher than BZ, were also shown to be more aboudant. The extracts of YS and CW also showed strong antioxidant activities, using the linoleic acid peroxidation and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity. However, the extract from BZ had less active antioxidant activity on linoleic acid peroxidation and DPPH free radical-scavenging activity of less than 70% than other extracts. The DPPH free radical-scavenging activity seems to relate with the antioxidant activity of linoleic acid peroxidation. The propolis with antioxidant activity also had DPPH free radical-scavenging activity. The extracts of YS and CW had effective antimicrobial activities on Staphilococcus aureus, Bacillus subtilis, Salmonella typhimurium and Candida albicans. Strong antioxidant, radical-scavenging and antimicrobial activities of YS and CW seemed to relate with high values, total polyphenol, and flavonoid contents.