天然产物中活性成分提取分离及分析技术

综述天然产物中活性成分的提取分离及分析技术,并着重对萃取技术、色谱技术进行论述。     

离子液体在天然活性成分分离中的应用研究进展

离子液体是由阴、阳离子组成的低温熔融盐,几乎没有蒸汽压,稳定性好,溶解能力强,结构可设计,优点突出,被认为是可替代传统溶剂的新型"绿色溶剂",在天然产物的提取分离研究中应用广泛。本文从离子液体联用超声波、微波、双水相萃取、酶法辅助与固相萃取等方面,综述了近年来离子液体在黄酮、萜类、生物碱、色素等天然成分提取分离中的应用情况,介绍了离子液体与其它技术联用的性质和分离机制,探讨了离子液体选择性差、黏度高、回收难及流失严重等问题,并提出了相应的解决思路,以期为离子液体在天然活性成分分离方面的应用提供借鉴和参考。     

银杏功能活性成分提取分离技术研究进展

概述了银杏天然功能成分黄酮、内酯的化学结构、性质和药用价值,重点介绍了高速逆流色谱、超临界、微波、超声、高效液相色谱等方法的实验原理、优缺点及其在银杏功能成分提取分离中的研究成果,指出了各种技术目前存在的问题,并对银杏功能成分的提取、分离、纯化及深加工产品的开发前景进行了展望。     

红豆杉内生真菌代谢产物的分离与鉴定

从红豆杉树皮中分离到了一株能产生物活性化合物的青霉菌,并对该菌株的发酵产物进行了分离和分析,从中提取分离到了2种化合物。经过图谱分析和文献比对,确定这2种化合物的结构为过氧麦角甾醇和贝诺酯。过氧麦角甾醇具有抗肿瘤、抑菌等活性,贝诺酯是一种应用广泛的镇痛消炎药,本实验中产量分别为2和1.5 mg/L。其他成分经GC/MS分析主要为十三酸、十八烯酸等脂肪酸化合物。本实验是首次从植物内生真菌中分离得到贝诺酯,也是天然贝诺酯的首次报道。     

余甘子树皮提取物抗氧化及清除自由基活性初步研究

余甘子树皮提取物的主要成分为局部棓酰化的聚原翠雀定-原花青定混合物,具有强抗氧化活性的化学结构特征.试验结果表明,采用超声波强化提取、冷冻絮凝沉降和大孔树脂吸附等方法提取分离获得的目标产物对1,1-二苯基-2-苦基-肼(DPPH)自由基的清除效率平均达91.13%,略高于茶多酚;对金属离子Fe2 的络合能力达358mg/g;抑制脂质过氧化能力强于马尾松树皮提取物.研究表明余甘子树皮提取物可望进一步开发成为新型天然抗氧化及自由基清除剂.     

毛杨梅树皮提取物抗氧化及清除自由基活性初步研究

毛杨梅树皮提取物中的主要成分为局部棓酰化的聚原翠雀定,具有比原花青定抗氧化活性更强的化学结构特征.本研究以水为提取剂,通过强化提取、絮凝沉降、溶剂萃取、吸附分离等手段从树皮中提取分离得到产物,并经花色素反应定性和IR谱图鉴别.用凝胶渗透色谱法(GPC)和蒸汽渗透压法(VPO)测定产物的相对分子质量(Mr)及其分布,产物中95%以上组分的数均相对分子质量(Mn)为1 705(相当于聚合度4～5),其余组分的Mn为798.用化学法测定目标产物分子中C-3的棓酰化度为38%.生物活性功能测定结果表明,目标产物能明显抑制油脂过氧化;络合Fe2 金属离子能力为181 mg/g;1 mg目标产物对1,1-二苯基-2-苦基肼(DPPH)自由基的清除速率为0.23 mg/min,清除率为92%(试验浓度:产物与DPPH质量比为1:1.8),强于马尾松树皮原花色素试样.初步研究结果表明,毛杨梅树皮提取物可望进一步开发成为新型天然抗氧化及自由基清除剂.     

桉树次生代谢产物作为植物源农药的研究进展

桉树次生代谢产物丰富,主要成分可作为植物源农药应用.文章综述了桉树次生代谢产物的成分及提取工艺,并对桉树次生代谢产物的杀虫活性、杀菌活性和除草活性的研究作简要介绍.     

毛杨梅树皮提取物抗氧化及清除自由基活性初步研究

毛杨梅树皮提取物中的主要成分为局部梧酰化的聚原翠雀定，具有比原花青定抗氧化活性更强的化学结构特征。本研究以水为提取剂，通过强化提取、絮凝沉降、溶剂萃取、吸附分离等手段从树皮中提取分离得到产物，并经花色素反应定性和IR谱图鉴别。用凝胶渗透色谱法（GPC）和蒸汽渗透压法（VPO）测定产物的相对分子质量（Mr）及其分布，产物中95％以上组分的数均相对分子质量（Mn）为1705（相当于聚合度4-5），其余组分的Mn为798。用化学法测定目标产物分子中C-3的掊酰化度为38％。生物活性功能测定结果表明，目标产物能明显抑制油脂过氧化；络合Fe^2＋金属离子能力为181mg／g；1mg目标产物对1，1-二苯基-2-苦基肼（DPPH）自由基的清除速率为0．23mg／min，清除率为92％（试验浓度：产物与DPPH质量比为1：1．8），强于马尾松树皮原花色素试样。初步研究结果表明，毛杨梅树皮提取物可望进一步开发成为新型天然抗氧化及自由基清除荆。     

超声空化效应及其对植物活性成分抗氧化性的影响

指出了超声波提取技术因具有提取率高、耗时短、温度低等优点被广泛应用于植物活性成分的提取中,从超声波提取法的原理入手,对其在植物活性成分的提取中的应用以及超声空化对活性成分的抗氧化性影响的机理进行了综述,为后续超声波提取的应用提供一定参考。     

施氏活性保鲜人参通过鉴定

从一种中草药中提取分离有效成分,做为人参天然保鲜剂,不仅可以防止人参霉变和腐烂,而且能够较长时间地保持人参的鲜活形态、活性成分和组织细胞的活力.这是辽宁省分析测试技术研究中心高级工程师施文奎最近研究成功的,并通过市级成果鉴定. 专家们认为,这种新颖的人参生物保鲜     

超临界C02萃取沙棘果渣中β--胡萝卜素的初步研究

用超临界CO2流体萃取沙棘果渣得到橘红色提取物，经试验确定了超临界CO2流体萃取沙棘果渣的最佳工艺条件。讨论了萃取压力，萃取温度，分离压力，分离温度，CO2流量，时间等对沙棘果渣有效成分提取的影响，并对沙棘果渣提取物性质做了初步试验。     

Traditional and medicinal uses of mangroves

This review examines the recent investigations on the biological activities of extracts and chemicals identified from mangroves (mangroves, mangrove minors and mangal associates). It describes how people have and are using mangroves on a traditional basis. It also describes the world's mangrove resources and products, in terms of their economical importance, medicinal values and other uses and functions. The economical uses of products from mangrove ecosystems are many and varied. Traditionally, the mangroves have been exploited for firewood and charcoal. Use has also been found for mangroves in the construction of dwellings, furniture, boats and fishing gear, tannins for dyeing and leather production. The mangroves provide food and wide variety of traditional products and artefacts for the mangrove dwellers. Extracts and chemicals from mangroves are used mainly in folkloric medicine (e.g. bush medicine), as insecticides and piscicides and these practices continue to this day. However the extraction of novel natural chemical compounds from mangroves, in addition to those already known to the pharmacopoeia of the people is in its infancy. A knowledge of the biological activities and/or chemical constituents of plants is desirable, not only for the discovery of new therapeutic agents, but because such information may be of value in disclosing new sources of already known biologically active compounds. It is of further value to those interested in deciphering the actual value of folkloric remedies.     

宁波苦丁有效成分提取方法的比较及其抗氧化活性的研究

采用水蒸气蒸馏法(SDE)、乙醇法(EE)、超声波法(UWE)、微波法(MAE)和超临界CO2萃取法(SCDE)提取宁波苦丁有效成分,得率分别为:0.048%、0.011%、0.631%、0.522%和0.935%,毛细管GC-MS法分别鉴定出10、9、12、9和20种成分,体外抗氧化活性测试均显示了抗氧化结果,活性强度依次为:超临界CO2萃取法＞超声波法＞水蒸气蒸馏法＞乙醇法＞微波法.     

白桦树皮中桦木醇超临界二氧化碳萃取的研究(英文)

桦木醇,一种药用五环三萜成分,大量存在于白桦(Betulaplatyphlly)树皮中。白桦树皮于2000年9月采集自黑龙江省塔源林场。超临界流体萃取技术(SFE)是一种新型分离技术,广泛用于药物和天然产物生产。本文研究了利用超临界CO2萃取技术从白桦皮中提取桦木醇的工艺条件,系统分析了携带剂用量、萃取压力和萃取温度等参数对桦木醇提取率的影响。结果表明,最佳的萃取条件为:每克桦树皮粉所用携带剂用量为1.5mL,萃取压力为20Mpa,萃取温度为55C,CO2流量为10kg/h,分离压力和分离温度分别为5.5Mpa和50C。图4参6。     

Unbiased evaluation of bioactive secondary metabolites in complex matrices

The majority of bioactive principles in a complex matrix such as natural products and botanical medicines are secondary rather than primary metabolites. In addition to being chemically diverse, the bioactivity of an ethnobotanical can comprise from one to several bioactive compounds, present in a complex mixture. Conventional discovery efforts utilize bioassay-guided fractionation (BGF) to isolate individual active compounds. When applied to complex natural products, BGF is often challenged by an apparent loss of activity during fractionation, resulting in weakly active isolated compounds. Metabolomic analysis can potentially complement existing the BGF paradigm by capturing the chemical complexity of the metabolites. The proposed biochemometric approach establishes a link between the chemistry of a secondary metabolome and a deserved health impact, using a high-throughput, high-resolution capable biological endpoint. The proof of principle is demonstrated for the anti-tuberculosis (TB) activity of the Alaskan ethnobotanical, Oplopanax horridus. Biochemometric analysis identified the 100 most active constituents from thousands of metabolites in the active extract by means of 2D orthogonal chromatography using countercurrent and GC-MS methods. Previously isolated O. horridus phytoconstituents were used as reference markers of known structure and bio (in)activity. Positive correlations allowed distinction of anti-TB actives from inactive compounds. A total of 29 bioactives from 3 main structural classes were assigned based on MS data. Biochemometric analysis is a new tool for the standardization of herbal medicines and ethnobotanicals, as well as for drug discovery from nature. The method can assign multiple active compounds in complex mixtures without their prior isolation or structure elucidation, while still providing an interface to structural information.     

A new epicatechin gallate and calpain inhibitory activity from Orostachys japonicus

Calpains are calcium-dependent proteases that cleave a variety of intracellular substrates. The overactivation of mu-calpain is associated with a wide range of disease conditions. To search for calpain inhibitors from natural products, the phytochemical constituents of the ethyl acetate fraction of the whole plant of Orostachys japonicus (Crassulaceae) were studied. The various chromatographic separation of this fraction led to the isolation of a new tannin, (-)-epicatechin 5-gallate (1) along with 9 known compounds. Their structures were elucidated by spectroscopic and chemical analyses. Among them, (-)-epicatechin 5-gallate (1) and kaempferol (9) exhibited moderate inhibitory activity against mu-calpain with IC(50) values of 18.0+/-2.9 and 15.4+/-2.0 microg/ml, respectively.     

Extraction of betulin from bark of Betula platyphylla by supercritical carbon dioxide extraction

Betulin, which is a medicinal pentacyclic triterpene, is abundant in the bark of white birch (Betula platyphlly). The bark of birch was collected at Tayuan Forest Farm of Jiagedaqi, Heilongjiang Province in September 2000. Supercritical fluid extraction (SFE) that is a new separation technology has been used for the processing pharmaceutical and natural products. In this paper, the extraction of betulin from the bark of birch by supercritical CO2 extraction was studied. The authors investigated and analyzed a few parameters such as modifier dosage, extraction pressure and extraction temperature. The optimal extraction conditions showed that the modifier dosage used for per gram bark powder was 1.5 mL, the extraction pressure was at 20 Mpa, and the extraction temperature was at 55 ℃. The velocity of flow of liquid CO2 was at 10 kg/h. The pressure and temperature in separation vessel were at 5.5 Mpa and 50 ℃, respectively.     

银杏叶有效成分的研究与资源的开发利用

银杏树是我国特产经济植物,含有多种有效成分,在医疗和保健等领域有着广泛的用途。本文对银杏的有效化学成分、影响银杏有效成分的因素、银杏的医用和保健效能及银杏中有效成分的提取与测定技术等进行分析与综述。