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国家海洋局二所开发出高活性降血压肽在国际科学基金资助及国家海洋局的支持下,国家海洋局第二研究所研究开发出一种高活性降血压肽。经研究,该所的科研人员发现,鲢鱼和贻贝中含有的肽可以治疗高血压症。他们以鲢鱼和贻贝作原料,采用分步复合酶酶解及活性修饰等先进工艺,从中提     

降血压肽的研究进展

本文主要从降血压肽的作用机理、制备方法、分离纯化技术及活性测定手段等方面,结合国内外的相关研究,综述了降血压肽领域的研究进展。并在此基础上,展望了食源性降血压肽于医疗保健方面的发展前景。旨在为降血压肽的进一步深入研究提供依据,为其产业化生产及市场推广提供参考,为降血压治疗提供新的选择。     

贻贝蛋白酶解降血压肽的降压活性及相对分子质量与氨基酸组成

以贻贝（Mytilus coruscus）为原料制取降血压肽,采用均匀设计试验探讨了不同酶解条件对其ACE( angiotensin converting enzyme) 抑制活性的影响,利用高效液相色谱分析了其相对分子质量分布,以氨基酸自动分析仪分析其氨基酸和游离氨基酸组成;并利用自发性高血压大鼠（SHR)饲喂试验检测其降血压活性。结果表明,对于P1酶来说, 酶量从25~175 IU• mL-1,酶解时间从2~7 h,随着酶解程度的提高,其ACE抑制率下降;其最高的ACE抑制率为88.08%,对应的最佳酶解条件为：酶量25 IU•mL-1,酶解时间2 h,pH 7.0,酶解温度60 ℃。此外发现降血压肽的相对分子质量在1.6 ku以下,其中10肽以下的短肽约占50.4%,证实了降血压肽主要以分子量较小的短肽组成。降血压肽游离氨基含量为8.8 g•（100g）-1,水解氨基酸总量为59.6 g•（100g）-1,疏水性氨基酸含量为24.86 g•（100g）-1,氨基酸组成比例平衡,必需氨基酸含量丰富,其中含量最高的氨基酸是谷氨酸,占8.57%。此外以3.0 g•kg-1体重的降血压肽样品剂量饲喂SHR,在饲喂后2～6 h降压效果显著,平均降低幅度为18～28 mmHg（P＝0.05）。研究表明以贻贝等水产蛋白为原料可开发具有高ACE抑制活性和显著降血压作用的降血压肽。     

国外简讯

从大马哈鱼中提取降血压活性肽日本北海道食品加工中心研究成功从大马哈鱼头部提取降血压的保健药品与食品。提取方法是将大马哈鱼头洗净后捣碎、加蛋白酶磨成糜浆状，使蛋白质转化成活性肽，其分子量达３００。此种活性肽具有生理活性，能抑制血压上升因子—高血压蛋白Ⅰ...     

血管紧张素转换酶（ACE）的提取与活性验证

在从紫菜中提取制备降血压肽的研究中,为筛选能够抑制血管紧张素转换酶（ACE）活性的功能肽,需要大量ACE进行体外检测。但ACE成本昂贵,本文利用硫酸铵分级盐析法提取猪肺组织中的ACE,测其酶活力为15．45×10^-3U／mg,比活力为33．80×10^-3U／mg。通过卡托普利来验证其抑制效果,抑制率达49．15％。采用本实验室初步制得的紫菜降血压肽对自制ACE和商品ACE的活性进行抑制,测定IC50发现该抑制剂对2种ACE的抑制效果差异不大,且活性较为稳定,因此所提取的ACE粗酶液可直接用于降血压肽的体外检测实验。     

我国海藻中抗氧化活性物质的研究进展

近年来一些研究人员从海藻中分离出多种具有抗氧化活性的物质,如海藻多糖、多酚、超氧化物歧化酶、不饱和脂肪酸、牛磺酸、维生素类等,并对它们的来源、在海藻中的含量、结构、活性及作用机理等方面进行了研究。地球上海洋资源丰富,海藻种类繁多,海藻中富含的抗氧化活性物质具有活性作用强、结构复杂、副作用低等优点,为海洋医药与生物制品的开发提供了良好的天然产物来源。本文综述了海藻中抗氧化活性物质的研究进展,并结合相关研究做出了分析和探讨,以期为海洋医药和生物制品的开发提供理论基础。     

龙须菜浅海筏式养殖新技术

龙须菜,学名江蓠,为江蓠科植物,暖湿性海藻种类,它富含海藻多糖、碘、钙、微量元素。藻体外层的粘质主要成分是Fucoidan,能有效清除胃粘膜表面的细菌和大肠杆菌。经研究表明,龙须菜有清肺通便、养颜瘦身、降血压血脂和调节身体机能等功效。     

紫菜降血压肽酶法制备工艺的优化

摘要：降血压肽又称为血管紧张素转化酶抑制肽,是具有降血压活性的生物活性肽,对高血压患者有显著疗效。为探讨从紫菜中制备降血压肽的酶法工艺,本实验选用AS．1398中性蛋白酶、胰蛋白酶、复合酶、木瓜蛋白酶、碱性蛋白酶、风味蛋白酶等6种蛋白酶分别对紫菜进行酶解,通过对其酶解液的ACE抑制活性和水解度的比较,发现采用AS．1398中性蛋白酶酶解的产物ACE抑制活性最高。对AS．1398中性蛋白酶的酶解工艺进一步优化,确定其最佳酶解工艺为：温度50℃、pH值7．5、加酶量E／S10000U·g^-1。在此条件下,酶解4h和10h的酶解产物抑制活性最高均达70％以上,并发现紫菜酶解液的ACE抑制率与水解度的增长不成显著的线性关系。     

鱼降压肽的酶法制备工艺及其理化性质研究

采用高压液相色谱测定降血压肽的血管紧张素转化酶抑制活性,对碱性蛋白酶水解草鱼蛋白制备鱼降压肽进行研究。结果表明,碱性蛋白酶水解草鱼蛋白制备鱼降压肽的较佳工艺条件为：pH9.0、温度50℃、酶与底物比48AU.kg-1、水解度34.52%。鱼降压肽成分分析结果显示,鱼降压肽中可溶性氮含量为81.26%,肽含量为72.81%,脂肪为0.12%,水分为3.54%,灰分为9.47%。鱼降压肽的血管紧张素转化酶抑制活性为70.35%;体积排阻色谱测定鱼降压肽的相对分子质量在124～10581之间,主要集中在124～1062之间;溶解度的测定结果表明,鱼降压肽在pH3.0～11.0时溶解度为96.0%左右,可广泛应用于食品中。 关键词：草鱼; 降压肽;碱性蛋白酶;高压液相色谱;相对分子质量;体积排阻色谱     

国家海洋局二所开发出高活性降血压肽

在国际科学基金资助及国家海洋局的支持下，国家海洋局第二研究所研究开发出一种高活性降血压肽。经研究，该所的科研人员发现，鲢鱼和贻贝中含有的肽可以治疗高血压症。他们以鲢鱼和贻贝作原料，采用分步复合酶酶解及活性修饰等先进工艺，从中提取出降血压肽，经冷冻干燥，制剂成型。经过对患有高血压症的老鼠进行试验，证明该药降压效果显著。对病鼠的给药剂量为3g／kg体重，6h后，老鼠的血压平均下降20～25mmHg，最大降幅达30mmHg。经安全性检测，证明此药安全、无毒副作用。     

大型海藻育种技术研究进展及其应用

大型海藻栽培业是全球最活跃的渔业产业之一，近二十年增幅是整体渔业增幅的两倍以上，发展前景十分广阔。其中，中国大型海藻产量占全球总产量的59%，海带、紫菜、裙带菜、龙须菜以及羊栖菜产量均排名世界第一。水产种业是水产养殖业的“芯片”和整个产业链的源头，大型海藻产量99%来自人工栽培，这更体现了新品种对产业的贡献度和重要性。但目前经过审定的大型海藻新品种仅有24个，约占海水养殖新品种的18%，与其产量占比并不匹配。为此，本文介绍了大型海藻产业的特点、近60年育种技术进展和育种成果，并针对大型海藻育种技术发展现状提出了相关建议，以期为大型海藻育种研究提供一些思路。     

大型海藻生境的生态功能及其在海洋牧场应用中的探讨

大型海藻是近岸海洋生态系统生态过程的重要驱动者之一,由大型海藻所形成的海藻场栖息地在维持海洋生物摄食、生长和繁殖等生命活动中扮演着极为重要的角色。然而,近年来受环境变化和人类活动等因素的影响,全球范围内许多沿海国家都出现了海藻场快速退化的现象,且对以海藻场为关键栖息地的海洋生物造成了不可忽略的影响,这一状况在我国尤为严重。为保障海洋生物资源可持续利用,海藻场修复已成为我国近岸海域生态环境保护的重要工作之一。但由于对海藻及其构造生境的生态功能认识不足,有关海藻场修复的目标定位、实现路径等存在较大的盲目性。本文从海藻场修复的角度出发,先分别对海藻及其构造生境的生态功能进行了阐述,而后对海藻养殖区是否可替代天然藻场被纳入到海洋牧场的建设中以及海藻生境生态功能的量化测定提出了几点思考,以期为今后海藻场修复工作合理、高效地开展和海藻养殖产业的可持续发展提供参考。     

Antibacterial benzaldehydes produced by seaweed-derived Streptomyces atrovirens PK288-21

Marine-derived actinomycetes (87 strains isolated from seaweed and 98 strains isolated from marine sediment) were screened for antimicrobial activity against bacterial fish pathogens. The most potent active strain (PK288-21) isolated from the rhizosphere of the marine seaweed Undaria pinnatifida was identified as Streptomyces atrovirens by 16S rDNA sequence analysis. Two active compounds were isolated from a culture extract of strain PK288-21 by silica-gel flash chromatography and high-performance liquid chromatography. The structures of the two compounds were identified as 2-hydroxy-5-(3-methylbut-2-enyl)benzaldehyde (B1) and 2-hepta-1,5-dienyl-3,6-dihydroxy-5-(3-methylbut-2-enyl) benzaldehyde (B2) by nuclear magnetic resonance and high-resolution fast atomic bombardment mass spectroscopy. The antimicrobial activities of the two compounds were tested against bacterial fish pathogens and expressed in terms of the minimum inhibitory concentration (MIC). Metabolite production was found to be optimized in A1BFe medium following the screening of eight different media. The two compounds killed Edwardsiella tarda after 12?h and Streptococcus iniae after 16?h at the MIC. Compound B1, 2-hydroxy-5-(3-methylbut-2-enyl)benzaldehyde, is a new benzaldehyde derivative, and this is the first time that either of these compounds have been reported in the genus Streptomyces.     

Potential of Cellulase From Bacillus megaterium for Hydrolysis of Sargassum

Bacterial cellulase can be a promising biotechnological approach in seaweed degradation to facilitate extraction of bioactive molecules. In the present study, bacterial cultures were isolated from marine and terrestrial samples and screened for cellulase production. The selected cultures were grouped by random amplification of polymorphic DNA (RAPD) profiling, and the cultures showing a distinct banding pattern were identified by 16S rDNA sequence analysis. Cellulase from Bacillus megaterium (CB-sw1-I), a native isolate, was purified by ion-exchange chromatography with a purification fold of 6.91 and specific activity of 1.66 U. The purified enzyme with molecular weight of 43 kDa was optimally active at pH 6.0 and temperature of 60°C. The potentiality of enzyme in degradation of Sargassum thallus was evident with an increase in reducing sugar. Morphology of the thallus after 10 days digestion observed by scanning electron microscope also provided additional evidence for degrading ability of the enzyme. This enzyme could subsequently be used in hydrolysis of seaweed for extraction of bioactive molecules.     

海藻产品质量安全风险研究

藻类作为一种富含生物活性物质的重要天然资源,越来越受到广大消费者的青睐,但藻类食物在食品安全方面潜在的危害也是不容忽视的.本研究对中国养殖海藻产品质量安全总体概况进行了介绍,对中国海藻产品存在的主要质量安全问题及隐患进行了分析.指出中国海藻产品中重金属、有机污染物及其他有毒有害物质是主要的安全隐患,并针对存在的问题提出...     

Antioxidant and Angiotensin I Converting Enzyme Inhibition Effects and Antihypertensive Effect in Spontaneously Hyertensive Rats of Peptide Isolated from Boiled Abalone By-Products,Hallotis discus hannai

ABSTRACT

Abalone is a marine gastropod that is an important fishery and food industrial resource, massively maricultured in Asia, Africa, Australia, and America. Marine by-products from boiled abalone, normally discarded as industrial waste in manufacturing plants, were fractionated and concentrated using an ultrafiltration membrane system (? 1 kDa). In this study, the antioxidant and angiotensin I converting enzyme (ACE) inhibition effects of the boiled abalone by-products (BABs) were investigated. BABs have high antioxidant activities against free radicals (1,1-diphenyl-2-pycryl-hydrazyl (DPPH), hydroxyl, peroxyl, and superoxide radicals), reactive oxygen species (ROS) stress, and DNA damage in H₂O₂-treated RAW 264.7 macrophages. The structure of the purified peptide was identified to be ATPGDEG (MW 752 Da), and the ACE inhibition pattern of the peptide was found to be noncompetitive. In addition, the peptide exhibited an antihypertensive effect according to time-course measurement after oral administration to spontaneously hypertensive rats (SHR). BABs from this genus may be potential candidates for the development of unique natural substances for further industrial applications as functional foods and pharmaceuticals.     

Identification of angiotensin I-converting enzyme inhibitory peptides derived from salmon muscle and their antihypertensive effect

ABSTRACT:   The salmon peptide digested from salmon muscle showed a strong inhibitory activity against the angiotensin I-converting enzyme (ACE). The antihypertensive effect of the salmon peptide on spontaneously hypertensive rats (SHR) was examined. After the single intravenous administration of the salmon peptide at a dose of 30 mg/kg body weight, the systolic blood pressure (SBP) was significantly reduced against the control. Further, a double-blind, placebo-controlled, parallel-group study determined the efficacy of the salmon peptide in mild hypertensive subjects. The SBP, after a 1.0 g of salmon peptide intake, was significantly reduced at 4 weeks after the intake, and 2 weeks after the intake finished, compared to the value before ingestion. Bioassay-guided separation of the salmon peptide, using a combination of column chromatographic techniques, led to the identification of 20 active di- and tri-peptides, including Ile-Val-Phe and Phe-Ile-Ala as two new ACE inhibitory tripeptides. Ile-Trp had the strongest ACE inhibitory activity (IC₅₀ = 1.2 μM) in vitro , and contributed 5.2% to the total ACE inhibitory activity. The salmon peptide and Ile-Trp showed a digestive resistance by in vitro assay, which mimicked the digestive organ, and had no affinity for factors related to blood pressure regulation, except for the ACE inhibitory activity.     

夏季柘林湾-南澳岛海洋牧场营养盐的空间分布及其评价

柘林湾-南澳岛海洋牧场由网箱养殖区、贝类底播区、海藻养殖区和人工鱼礁区4个不同的功能区构成。根据2011年夏季（8月）海水营养盐的调查数据,分析其表层海水营养盐含量的空间分布特征,并对其污染现状进行综合评价。结果表明,氮、磷营养盐的空间分布均呈现由西北部柘林湾近岸海域向东南部海域递减的变化趋势。不同功能区中,无机氮（DIN）和活性磷酸盐（PO4-P）的高值出现在网箱养殖区,硅酸盐（SiO3-Si）的高值出现在贝类底播区,人工鱼礁区的营养盐水平均较低。单因子污染指数、污染物分担率和综合污染指数评价结果也表明,海洋牧场受到DIN和PO4-P污染的程度以及富营养化程度均呈现由西北海域向东南海域递减、近岸向离岸递减的变化趋势。网箱养殖区受DIN和PO4-P污染最重,呈现严重富营养化,其次为贝类底播区,而人工鱼礁区和对比区受到的污染程度均较轻。     

基于拉格朗日法的海藻场有机碎屑离岸输运研究

海藻场在海藻凋落盛期向海洋输送大量有机碎屑,为海藻场外围海域提供大量初级生产力,并在沉降后实现碳汇功能。本研究采用具有拉格朗日质点追踪模块的三维海洋数值模式(Estuarine Coastal Ocean Model, semi-implicit, ECOM-si),结合潮位、流速及漂流浮标轨迹跟踪观测,研究了枸杞岛西北侧天然海藻场有机碎屑输运与沉降的动力学机制及碳汇功能。结果显示,海藻场对周边海域碳汇贡献的空间分布格局呈现为以海藻场为中心的高值区,向西北–东南海域扩展分布并递减。水动力强弱和海藻碎屑粒径差异导致其沉降后的空间分布差异显著。大潮期间,海藻场对邻近海域碳汇贡献最高为699 g C/(hm2·d)。碎屑粒径越小、沉降速度越小的海藻碎屑对外围海域碳汇贡献范围越大。海藻场碳汇功能不局限于邻近海域,不同粒径海藻碎屑每天为海藻场5 km外海域提供有机碳约7.5~33.7 kg C;小潮期间水动力较弱,约90%以上的海藻碎屑沉降至5 km以内海域。海藻场碳汇功能集中于沿岸邻近海域,对邻近海域有碳汇贡献的区域范围小,但强度大,最高为817 g C/(hm2·d)。海藻碎屑脱落时的潮流方向和海藻场所处区位也是影响海藻场有机碎屑输运沉降和碳汇归趋的重要因素。赋予拉格朗日质点单位碳含量后,拉格朗日法在海藻场有机碎屑离岸输运沉降机制研究中具有可行性,可有效评估典型近岸海藻场对周边海域碳汇的贡献及主要动力学因子的作用。本研究可为我国海藻场本底调查及其生态辐射范围评估提供参考。