响应面法优化云芝多糖提取条件的研究

为了探索云芝菌丝体多糖水浸提的最佳条件,在单因子实验的基础上,采用合理的实验设计方案,应用响应面法(RSM)优化云芝多糖的提取条件。依据回归分析确定多糖提取率的影响因子,求得最佳水浸提条件为:提取温度85℃,浸提时间105min,液料比27∶1,云芝多糖的提取率为7.27%。实验结果表明,响应面法对云芝菌丝体多糖的提取条件优化合理可行,为提高多糖的提取率提供了理论依据。     

云芝多糖提取工艺的优化及其性能研究

采用超声波提取法,选取溶剂、超声时间、温度、pH作为提取因素,进行单因素实验和L9(34)正交实验,来优化云芝多糖的提取工艺,探讨在常见食品添加剂、常见饮料、一些重金属离子等存在下对云芝多糖稳定性的影响,并对云芝多糖进行了体外抗氧化活性研究。结果表明,云芝多糖的最佳提取条件为以2%的Na2CO3溶液为提取介质,温度45℃,pH为8.5,超声时间50 min,提取率可高达13.87%,云芝多糖在常见食品添加剂、碳酸饮料、苏打水等介质中稳定性较好,云芝多糖对羟基自由基具有较好清除能力,云芝多糖有良好的开发应用价值。     

云芝多糖研究进展

近年来,药食用真菌因具有多种生物学功能而受到重视,成为研究热点。云芝多糖由云芝或从其发酵液中分离提取,具有突出的药食用功效和生物活性。文中从云芝多糖的结构、性质、提取纯化、发酵生产、用途与展望等方面进行了综述,为云芝多糖的进一步研究与开发提供参考。     

发酵产云芝胞外多糖的分析及其在卷烟中的应用

对发酵产云芝胞外多糖进行提取和脱蛋白处理得到精制云芝胞外多糖,之后过SepharoseCL-6B凝胶柱得到一个多糖组分,然后用红外光谱技术对该多糖组分的结构进行表征得知其为酸性多糖;将精制云芝胞外多糖以不同的浓度注入卷烟中,利用吸烟机捕集烟气粒相物计算出云芝胞外多糖在烟气中的转移率在2.76%～4.78%之间变动;用单料烟丝进行加香评吸实验,结果表明在精制胞外多糖添加量为0.04%时明显地改善了卷烟的吸食品质,起到掩盖杂气,去除刺激,改善余味的作用,使香气细腻程度有所提升。这为发酵产云芝胞外多糖在卷烟中的应用提供了一定的理论支持。     

复合酶法提取云芝多糖及其抗氧化活性

目的:优化复合酶解法辅助提取云芝多糖的提取工艺,并研究其抗氧化活性。方法:在单因素实验基础上,利用Box-Behnken方法进行酶浓度、p H、酶解时间和酶解温度四因素三水平实验设计,以多糖得率为响应值,采用响应面分析优化云芝多糖的提取条件。采用对云芝多糖清除DPPH自由基能力、清除羟自由基(·OH)能力和清除超氧阴离子(O_2~-·)能力的测定评价云芝多糖的抗氧化活性。结果:最佳提取条件为p H5.50,酶解时间37 min,酶解温度52℃,酶浓度2.50%,理论上云芝多糖的提取率为9.87%,验证实验的实际提取率为9.58%,与传统的热水浸提法提取率相比较,提高了43.63%。云芝多糖清除·OH、O_2~-·和DPPH自由基的IC_(50)分别为0.80、0.75、0.75 mg/m L,抗氧化活性研究中云芝多糖的各抗氧化活性均随多糖浓度的增加而上升。结论:复合酶解法辅助提取条件温和,方法简单,效率高,可在云芝多糖实际提取工艺中得到应用,得到的云芝多糖具有良好的抗氧化能力,可进一步的开发利用。     

云芝总发酵物及其多糖抗氧化活性比较研究

采用羟自由基和超氧阴离子自由基清除实验以及氧化损伤酵母细胞保护实验模型,研究了云芝总发酵物和云芝多糖的抗氧化活性.云芝总发酵物对于羟自由基清除的半最大效应浓度(EC50)为0.13mg/mL,其清除能力显著优于云芝多糖的0.16mg/mL和阳性对照Vc的0.25mg/mL(p＜ 0.05);云芝总发酵物对于超氧阴离子自由基清除的EC50为0.34mg/mL,优于云芝多糖(0.35 mg/mL).氧化损伤酵母细胞保护实验结果显示,与空白对照相比,云芝总发酵物可显著提高氧化损伤酵母细胞存活率(47.4％),其效果与添加的剂量呈正相关性(R＞0.9).这表明,云芝总发酵物对酵母细胞的氧化损伤有明显保护作用,且其作用优于云芝多糖.     

不同云芝菌株获得云芝胞内多糖比较

将不同产地的6个云芝菌株进行液体培养，通过多糖产量、多糖质量和蛋白质质量等指标，从中选出了3个优良菌株，采用高效液相凝胶过滤色谱法（HPGFC）测定这3个菌株提取物云芝胞内多糖的相时分子质量，并加以比较，根据实验的结果，确认菌株LS为液体发酵的首选菌株。     

樟芝菌丝体胞内多糖提取条件的研究

为了提高樟芝菌丝体胞内多糖的提取率,试验采用二次通用旋转组合设计方法,研究樟芝菌丝体多糖提取工艺条件中的提取时间、料液比、提取温度对提取率的影响.建立了回归模型并进了验证.通过研究可知:当提取时间为4.7h、液固比46倍、提取温度76.8℃时,樟芝菌丝体胞内多糖提取率的理论值为8.8%.并通过试验验证最优组合.     

真菌多糖对鼠李糖乳杆菌体外增殖的研究

通过液体发酵提取曲霉和云芝胞内胞外多糖,脱蛋白,制成一定浓度溶液.选用MRS培养基,采取试管法,试验曲霉和云芝多糖对鼠李糖乳杆菌增殖的影响,并将其应用于鼠李糖乳杆菌发酵乳的研究中.结果表明,0.5%(m/v)、1%(m/v)的曲霉多糖和云芝多糖对鼠李糖乳杆菌体外增殖均有极显著的效果(P＜0.05).不同浓度相比,2%(m/v)的曲霉多糖和1%(m/v)的云芝多糖更能提高鼠李糖乳杆菌的活性,缩短凝乳时间.初步显示,曲霉多糖和云芝多糖中含促生长因子.     

云芝糖肽水提醇沉提取工艺

避免了有毒溶剂使用,本文建立了水提醇沉法提取纯化云芝糖肽的技术方法,以期为云芝糖肽无公害生产提供参考。     

Sulfated modification of polysaccharides: Synthesis,characterization and bioactivities

BackgroundPolysaccharides are a kind of biological macromolecular substance with multiple biological effects. Natural polysaccharides derived from plants and fungi are known as ideal raw food supplements for health food and pharmaceuticals due to their few side effects. Sulfated modification could significantly improve structure characteristics, promote bioactivities, and even add new bioactivities to polysaccharides. Thus, sulfated polysaccharides are increasingly causing more attention, as they have been proved to possess a variety of biological activities, including antioxidant, anticancer, and immunoregulatory, and anticoagulant activities. Furthermore, recent advances in synthesis, characterization and bioactivities of sulfated polysaccharides can promote its application in the food industry or pharmaceutics.Scope and approachThis paper reviewed the main methods of sulfated modification, structural changes and the bioactivities of sulfated polysaccharide derivatives. We have comprehensively discussed biological activities of sulfated polysaccharides, emphatically the effects of sulfated group, composition, functional groups, as well as their replaced position on the bioactivities of sulfated polysaccharides, in order to reveal the potential mechanism of sulfation on bioactivities of polysaccharides.Key findings and conclusionsThis paper reviewed the recent research in the sulfated modification of polysaccharides and provided future directions for research in this area. There are many methods for sulfated modification, such as chlorosulfonic acid-pyridine method, concentrated sulfuric acid method, and sulfur trioxide-pyridine method, which could improve anti-coagulant, anti-oxidative, immunoregulation, anti-tumor, and anti-virus activities of polysaccharides. Sulfated modification could change bioactivities of polysaccharides due to their effects on structure characteristics. DS, monosaccharide compositions, replaced position of sulfated groups were considered to contribute to their bioactivities promotion. Further studies are required to explore the application of sulfated polysaccharides in pharmaceutical and food industries.     

Molecular Modification of Polysaccharides and Resulting Bioactivities

Polysaccharides are ideal natural resources for supplements and pharmaceuticals that have received more and more attention over the years. Natural polysaccharides have been shown to have fewer side effects, but because of their inherently physicochemical properties, their bioactivities were difficult to compare with those of synthetic drugs. Thus, researchers have modified the structures and properties of natural polysaccharides based on structure–activity relationships and have obtained better functionally improved polysaccharides. This review focuses on the major modification methods of polysaccharides, and discusses the effect of molecular modification on their physicochemical properties and bioactivities. Molecular modification methods mainly include chemical, physical, and biological changes. Chemical modification is the most widely used method; it can significantly increase the water solubility and bioactivities of polysaccharides by grafting onto other groups. Physical and biological modifications only change the molecular weight of a polysaccharide, and thereby change its physicochemical properties and bioactivities. Most of the molecular modifications bring about an increase in the antioxidant activity of polysaccharides, and among these, sulfated and acetylated modifications are very common. Furthermore, phosphorylation modification is the most common application to increase antitumor activity, and modified polysaccharides have been shown to have anti‐HIV activity as the result of sulfated modification.     

多糖微观构象与抗肿瘤活性关系研究进展

多糖因其特殊的结构而具有丰富的生物活性功能,而其中抗肿瘤功能已成为多糖研究领域的热点之一。然而,由于多糖结构的复杂性及传统光谱研究手段的局限性,以致于到目前为止多糖的结构与活性间的构效关系尚未深入探讨。基于此,本文从多糖结构与抗肿瘤活性的角度,具体阐述多糖的结构(如主链结构、螺旋构象等)对抗肿瘤活性的影响,探讨运用计算机分子模拟研究多糖微观构象与抗肿瘤活性关系的可行性,为抗肿瘤活性多糖的目的性筛选、进行分子修饰提供参考,为多糖的深度利用提供理论基础和科学依据。     

灰树花多糖结构特点及其生物活性研究进展

灰树花是一种药食两用真菌,灰树花多糖是其主要生物活性成分,具有抗氧化、抗肿瘤、免疫调节和抗乙型肝炎病毒等功效,近年来一直是药用真菌研究的热点。目前,多糖结构特点与生物活性之间的关系尚未明确。因此,该文基于灰树花多糖结构特征和生物活性最新的研究现状,对多糖分子进行分子质量、结构与活性之间关系的探讨,并对灰树花多糖的应用前景进行展望,旨在为灰树花多糖的开发利用提供一定的参考价值。     

A review on the isolation and structure of tea polysaccharides and their bioactivities

Tea polysaccharides were found to be mostly glycoconjugates in which a protein carries one or more carbohydrate chains covalently attached to a polypeptide backbone, usually via N- or O-linkages. It has been reported that they have showed various bioactivities, such as anti-cancer, anti-HIV, hypoglycemic and immunological activities, and so on. In this paper, the various aspects of the investigation results of tea polysaccharides in the past 20 years were summarized, including the extraction and purification processes, the structure and bioactivities.     

茯苓多糖的提取、结构、活性和作用机理研究进展

真菌多糖具有悠久的研究历史,且生物活性广泛。茯苓多糖来源于多孔菌科真菌茯苓(Poria cocos)的菌核,具有免疫调节、抗肿瘤、抗炎、抗氧化等多种功能活性,成为近年来的研究热点。该文主要综述茯苓多糖的提取工艺、结构、功能活性、作用机理以及安全性研究进展,最后对茯苓多糖的应用前景进行展望。     

天然多糖提取、纯化及生物活性研究进展

大量研究已经证实天然多糖具有抗氧化、抗衰老、抗肿瘤、降血糖和调节肠道菌群等功效,天然多糖在生物医药、食品和保健品等领域具有较好的开发潜力和应用前景,其提取、分离纯化、理化特性和生物活性受到国内外学者的广泛关注。但不同的原料、提取和纯化方法,导致天然多糖的结构和生物活性存在差异。本文系统综述了天然多糖最新的提取和分离纯化方法以及热点的生物活性,以期为天然多糖作为功能性食品及有效的治疗药物提供重要的参考,同时为未来基于人类健康的食品开发提供重要的依据。     

百香果皮多糖的分离纯化、结构特性及生物活性研究进展

百香果是一种生长在热带、亚热带的重要特色经济水果,多糖是构成百香果果皮的主要功能成分之一。百香果皮多糖因具有抗肿瘤、抗炎、降血脂和抗氧化等多种生物活性而备受国内外学者的高度关注。本文系统综述了国内外近十年来关于百香果皮多糖的提取、分离纯化、结构特性和生物活性的研究进展,并提出目前百香果皮多糖研究中存在的不足,以期为百香果皮多糖的研究与开发提供参考与借鉴。     

桑叶多糖的研究进展

桑叶多糖是桑叶的一种主要活性成分之一,具有多种药理作用和生物活性功能,是目前的一个研究热点.本文对国内外近年来关于桑叶多糖的提取、分离纯化、化学结构及生物活性等多方面进行了综述,为桑叶资源的深入开发起一定借鉴作用.     

枸杞多糖的提取方式、结构及生物活性研究进展

枸杞(Lycium barbarum)果实为传统的名贵滋补药材,在我国有2000多年的历史。枸杞多糖(Lycium barbarum polysacchavides,LBP)是枸杞中最重要的活性成分之一。在过去的几年中,LBP由于具有良好的生物活性而备受关注。然而,多糖的生物活性与其化学结构密切相关,而化学结构又被提取方式所影响。该文对LBP的提取方法、化学结构和主要生物活性的对应关系进行总结,比较通过不同提取方式制备得到的枸杞多糖的不同之处,旨在提出枸杞多糖的构效关系,关注特定结构和活性的枸杞多糖的定向提取。大部分研究表明,采用热水提取法制备的枸杞多糖多为含有酸性糖组分的杂多糖,其中的中性糖组分多以阿拉伯糖、葡萄糖及半乳糖为主。此外,枸杞多糖通过不同的机制显示出良好的抗氧化、免疫调节、抗肿瘤及神经保护活性。