分子遗传标记技术在中药材鉴定中的应用

分子遗传标记技术在中药材品种鉴别中的应用是中药现代化研究的一个重要方面,本文回顾国内外中药分子标记鉴定研究的历史及现状,分析了目前分子标记在中药鉴定应用中存在的问题并提出建议,进而展望这项技术应用的前景。中药材质量的规范化,为中药材遗传图谱的建立指明方向。     

菊芋粕菊粉的酶法提取、组成及抗氧化活性研究

本研究拟应用酶法提取技术解决菊芋菊粉工业化生产中的废弃物——菊芋粕再利用程度低的问题,并评价菊芋粕菊粉的抗氧化活性功效。对菊芋粕菊粉的果胶酶酶法提取的最佳条件通过响应面法进行了优化,并对菊芋初次水提菊粉(primary water-extracted inulin,PWI)和二次酶提菊粉(secondary enzymatic-extracted inulin,SEI)的组成成分和抗氧化活性进行了比较分析。响应面法优化确定的菊芋粕菊粉最佳酶法提取条件为:pH4.5、提取温度50 ℃、酶底比7.5 U/g、提取时间2 h,该提取方法所得菊芋粕菊粉的得率为35.30%±0.85%,与传统热水浸提法相比菊粉得率提高38.16%。组成分析结果显示,SEI的总糖和菊粉含量均显著高于PWI( P <0.05)。在菊粉聚合度方面,PWI中蔗果三糖和蔗果四糖含量较高,而SEI中蔗果五糖、蔗果六糖及其以上聚合度菊粉的含量较高。此外,SEI的抗氧化活性优于PWI。因此,果胶酶辅助提取方法有望为菊芋粕菊粉的再利用难题提供新的解决思路。     

真菌多糖研究进展

真菌多糖具有多种生物活性和保健功能,近年来成为生命科学、医药科学、食品科学等领域研究的热点.本文对真菌多糖的生物活性即抗肿瘤、抗病毒、降血压、降血脂、降血糖、抗氧化、抗疲劳、抗辐射等活性作了介绍,阐述了真菌多糖的提取方法即热水浸提法、酸提法、碱提法、酶法、超声波辅助法等6种方法,以及分离纯化方法即膜分离技术和色谱技术,最后对真菌多糖的应用前景进行了探讨.     

SSR标记技术在中药鉴定中的应用

中药是我国宝贵的资源,在疾病治疗、养生保健方面扮演着重要的角色。然而近年来,因鉴定方法不完善导致的中药安全事件屡屡出现,给中药临床应用带来极大挑战。传统的鉴定方法是中药药师凭借其长期积累的经验对中药材进行鉴定,虽然方法日趋完善,但其存在较大主观性,不可否认仍有它的局限性。科学技术不断发展完善,新技术、新方法也推动着中药鉴定学的发展,将传统的鉴定方法与现代的鉴定方法合理的结合在一起使用,才能对中药材进行更准确、科学的鉴定。近年来,高通量测序技术的发展,为分子标记技术的发展提供了良好的平台,为中药材的鉴定提供了更加准确可靠的手段。目前RAPD、AFLP、RFLP、SSR是应用最广泛的几种分子标记技术,各有其优缺点。SSR指的是基因组中由1-6个核苷酸组成的基本单位重复多次构成的一段DNA,SSR标记具有特异性高、重复性好、结果可靠、操作简单、对DNA要求不高等特点,在中药材的品种鉴定、植物种质鉴定、遗传图谱构建、遗传多样性分析等方面发挥着越来越重要的作用。对近年来SSR标记技术在中药鉴定中的应用作简要概述,旨在为该技术在中药材鉴定方面的进一步研究提供参考。     

甘草苷的提取纯化和药理作用研究进展

甘草是我国传统的中药材,含有多种生物活性成分,其中甘草苷是重要的黄酮类化合物,提取分离技术难度较大,总结发现甘草苷常用有机溶剂、加热回流、闪式提取、超声波辅助提取、微波辅助提取、高压脉冲电场法等方法提取,有机溶剂、大孔树脂、无机陶瓷超滤、超滤-络合萃取及反萃取技术进行分离纯化。与此同时,已有研究表明甘草苷具有抗抑郁、抗氧化、抗炎、抗病毒、解毒等药理作用,为进一步研究开发甘草苷提供了参考依据。     

基于微量筛选模型的48种中草药提取物乙酰胆碱酯酶抑制活性筛选及评价

采用微量筛选模型考察48种中药提取物的乙酰胆碱酯酶抑制活性。采用不同极性溶剂对中药材进行提取,采用微量筛选模型对不同浓度提取物的乙酰胆碱酯酶抑制活性进行考察,并采用Origin8.0计算其IC50值。结果表明,几种中药材的不同极性溶剂(水、80%乙醇、乙酸乙酯、石油醚)提取物有不同程度的乙酰胆碱酯酶抑制活性。其中黄柏、元胡的80%乙醇提取物,丹参的乙酸乙酯提取物的抑制率较高。当上述提取物在实验体系中的终浓度为76.92 mg/L时,抑制率分别为66.72±0.02%、52.67±0.04%、46.84±0.03%,其IC50值分别为295.12、229.09、1202.26 mg/L。本研究结果为从中草药中快速筛选乙酰胆碱酯酶抑制剂提供了方法和数据支持。     

中药材资源质量评价方法的研究进展

中药材资源是中医药的物质基础,其质量事关临床用药的安全性与有效性,其科学评价是中药产业现代化、标准化以及国际化的前提条件。中药材的性状特征、药效成分以及分子标记为迄今三类质量评价方法的主要依据。近年来,微性状鉴定及仿生识别技术的应用显著提高了基于性状特征评价中药材质量的准确性与客观性;中药指纹图谱、代谢组学技术与化学计量学的应用极大地促进了基于药效成分评价中药材质量的科学性及相应有效成分群的发现;基因组学及蛋白质组学的进展推动了分子标记的挖掘及相应分子鉴定技术的建立。上述方法学进展为中药材质量标准体系的建设和中药材资源的开发利用提供思路与借鉴。     

沈农一号马齿苋的多糖提取方法研究

分别采用热水法、低级醇法和酶法从沈农一号马齿苋中提取有效成分多糖并测定其含量。结果表明,酶法的浸提效果要优于热水法和低级醇法,提取率提高约10%。本实验首次运用纤维素酶辅助提取马齿苋多糖,收率提高。     

高压脉冲电场辅助酶法提取鹿托盘胶原蛋白北大核心CSCD

为了提高鹿托盘中胶原蛋白的提取率,采用高压脉冲电场技术辅助胃蛋白酶的方法提取胶原蛋白。以胶原蛋白提取率为指标,通过对胃蛋白酶添加量、脉冲数和电场强度进行单因素考察,采用正交实验对胶原蛋白提取条件进行优化。优选出鹿托盘胶原蛋白的最佳提取条件为:胃蛋白酶添加量2%、脉冲数8、电场强度20k V.cm-1,在该条件下鹿托盘胶原蛋白的提取率可达到(73.27±0.73)%。与普通酶法相比,高压脉冲电场辅助提取胶原蛋白的得率比普通酶法提高了10.34%,且处理时间较短。聚丙烯酰氨凝胶电泳结果表明所提取的胶原蛋白由α1、α2和β-亚基组成,结构特征表明胶原蛋白具有完整的螺旋结构和Ⅰ型胶原蛋白的特性。该研究可为高压脉冲电场用于胶原蛋白的提取提供理论参考。     

小檗红碱的化学与药理

小檗红碱在黄连等中药材中的自然含量很低,但相关药材中的小檗碱在加热条件下可以转化成小檗红碱而使其含量增加.随着对传统中药材微量成分药理活性和药用安全性的日益关注,小檗红碱在相关中药中的治疗作用及安全性已经引起天然药物学领域专家的重视,本文在参考最新文献的基础上,对小檗红碱的化学合成方法、含量分析方法和药理作用等方面进行综述,拟为相关中药质量研究与药理研究提供参考     

发酵麸皮多糖酶辅助提取工艺优化及其生物活性研究

通过响应面法优化提取发酵麸皮多糖的工艺,并评价其体外益生和抗氧化活性。以发酵麸皮多糖的得率为响应值,采用纤维素酶酶解与水浴浸提相结合的方法提取发酵麸皮多糖,以纤维素酶添加量、料液比、水浴浸提温度、水浴浸提时间为试验因素建立数学模型,筛选最佳提取工艺条件。通过测定还原力、DPPH和·OH自由基的清除能力对比发酵和未发酵麸皮多糖的体外抗氧化活性,并通过测定嗜酸乳杆菌、植物乳杆菌、两歧双歧杆菌的生长对比发酵和未发酵麸皮多糖的体外益生活性。结果表明,发酵麸皮多糖最佳提取工艺为:料液比1∶16(w/v),酶添加量1 000 U/g,水浴浸提温度90℃,水浴浸提时间60 min,在此条件下发酵麸皮多糖的得率实测值为73. 35%。发酵麸皮多糖具有较强的DPPH和·OH自由基的清除能力,可促进嗜酸乳杆菌、植物乳杆菌和两歧双歧杆菌的生长。     

葵花籽油的酶辅助压榨制备工艺优化

葵花籽是一种优质的油料资源,是世界第四大油料作物。葵花籽不但含油量高,葵花籽油以其高达90%的不饱和脂肪酸和富含维生素E、胡萝卜素等营养成分的特点,被称为"保健油",有延缓衰老、调节新陈代谢和降低胆固醇等功能。采用酶辅助压榨法制备葵花籽油,在提高出油率的同时保留油脂的天然风味。通过单因素实验法研究了酶的种类、酶添加量、pH值、液固比、温度和时间对压榨葵花籽油出油率的影响,以确定最佳的工艺条件。结果表明,最佳工艺条件为：选用纤维素酶,酶添加量为0.7%,pH为4.5,液固比为25%,酶解温度为55℃,酶解时间为2.5 h。在此最佳条件下,出油率是传统冷榨法的3.48倍,油脂提取率达85%。     

Enzyme-assisted extraction of bioactives from plants

Demand for new and novel natural compounds has intensified the development of plant-derived compounds known as bioactives that either promote health or are toxic when ingested. Enhanced release of these bioactives from plant cells by cell disruption and extraction through the cell wall can be optimized using enzyme preparations either alone or in mixtures. However, the biotechnological application of enzymes is not currently exploited to its maximum potential within the food industry. Here, we discuss the use of environmentally friendly enzyme-assisted extraction of bioactive compounds from plant sources, particularly for food and nutraceutical purposes. In particular, we discuss an enzyme-assisted extraction of stevioside from Stevia rebaudiana, as an example of a process of potential value to the food industry.     

Comparison of different extraction methods of polysaccharides from cup plant (Silphium perfoliatum L.)

The purpose of the present research was to compare the effects of four extraction methods on the extraction yields, physicochemical characteristics, and antioxidant activities of polysaccharides from the cup plant (Silphium perfoliatum L.) (CPPs). The extraction methods included the hot water extraction method (HEM), ultrasonic-assisted extraction method (UEM), enzyme-assisted extraction method (EEM), and the ultrasonic-enzyme-assisted extraction method (UEEM). Four corresponding CPP extracts, HEM-CPPs, UEM-CPPs, EEM-CPPs, and UEEM-CPPs, were obtained. The results indicated that there were notable differences between the extraction methods regarding the yield, average molecular weight, uronic acid content, monosaccharide proportions, and the antioxidant activities of the CPPs. HEM-CPPs were extracted with the lowest yield (6.44%). EEM-CPPs had the largest extraction yield (9.87%) and the most notable antioxidant abilities of ferric reducing power and free radical scavenging activity. According to correlation analysis, the higher antioxidant abilities of EEM-CPPs might be due to their smaller average molecular weight and a higher content of uronic acid than those of the other extracted CPPs. Therefore, EEM could serve as a promising technique for extracting CPPs.     

Optimisation of enzyme-assisted extraction of Erythronium sibiricum bulb polysaccharide and its effects on immunomodulation

Glycoconjugate Journal - In this study, polysaccharides of Erythronium sibiricum bulb were extracted using enzyme-assisted extraction technology and then optimised by response surface methodology....     

金龙胆草提取液体外抑菌活性分析

金龙胆草是传统道地中药材,但目前受到材料来源不足的限制,其应用和研究均受到很大限制,为更好地开发和应用该道地中药材,本研究以实验室野生金龙胆草和组培金龙胆草出发,分别采用热水浴和索式提取法对金龙胆草有效成份进行了提取和体外抑菌活性研究。结果表明,热水浴浸提法的抑菌效果优于索式提取法,均表现出对金黄色葡萄球菌和枯草芽孢杆菌这类革兰氏阳性菌有很好的抑制效果,最小抑菌浓度分别达到12.5 mg/mL和50 mg/mL。野生型提取液和组培型的提取液体外抑菌比较实验显示,野生型金龙胆草的抑菌效果要显著优于组培型金龙胆草提取液。这将为金龙胆草作为中药抗菌药的合理利用提供一定的指导作用,同时为减少抗生素的滥用造成的环境污染作出一定的贡献。     

Enzyme-assisted extraction of lycopene from tomato processing waste

A central composite design was used to optimize the enzyme-assisted extraction of lycopene from the peel fraction of tomato processing waste. Tomato skins were pretreated by a food-grade enzyme preparation with pectinolytic and cellulolytic activities and then subjected to hexane extraction. The factors investigated included extraction temperature (10-50 °C), pretreatment time (0.5-6.5 h), extraction time (0.5-4.5 h), enzyme solution-to-solid ratio (10-50 dm3/kg) and enzyme load (0-0.2 kg/kg). Overall, an 8- to 18-fold increase in lycopene recovery was observed compared to the untreated plant material. From a response surface analysis of the data, a second-degree polynomial equation was developed which provided the following optimal extraction conditions: T=30 °C, extraction time=3.18 h and enzyme load=0.16 kg/kg. The obtained results strongly support the idea of using cell-wall degrading enzymes as an effective means for recovering lycopene from tomato waste.     

Novel procedures for the extraction of fucoidan from brown algae

Sulfated polysaccharides, such as the so-called fucoidans, from brown algae exhibit a versatile biological activity, which is thought to be associated with their characteristic sulfated fucose backbone. The extraction of the target compound is one of the most important steps of the purification process. The correct adjustment of parameters, such as temperature, pH, and extraction time, greatly influences the yield and prevents the possible structural alteration of the sulfated polysaccharides. This review includes historical and current extraction procedures for sulfated polysaccharides and illustrates novel extraction techniques, which can effectively improve the extraction process. The use of ultrasound- and microwave-assisted extraction techniques is described, the potential of which has been underestimated to date. Furthermore, the enzyme-assisted extraction of fucoidans is in its infancy. It is assumed that further improvements of these procedures (e.g., by the application of computer-aided techniques) will have a major impact on the economics and the scalability of the extraction process as well as yielding a sugar fraction with a conserved sulfation pattern.     

土生曲霉转化三七中药材的研究

从土壤真菌中筛选出直接转化中药材三七化学成分的菌株YM31966,经鉴定该菌株为土生曲霉(Aspergillus terreus).以固态转化方式,结合化学提取分离方法,通过高效液相色谱、核磁共振及质谱等波谱检测,该菌株转化三七产物由三七皂苷nR2 、RX1和人参皂苷Rg1、Rd、Rh1、Rh4构成主体成分,而原三七成分Rb1、Rc、Re和R1、R3,R6等物质被分解.结果表明,土生曲霉是一株能转化中药材三七的微生物,它具有改变原三七化学成分,形成新化合物,以及提高某些原化合物成分含量的作用.     

Factors affecting emulsion stability and quality of oil recovered from enzyme-assisted aqueous extraction of soybeans

The objectives of the present study were to assess how the stability of the emulsion recovered from aqueous extraction processing of soybeans was affected by characteristics of the starting material and extraction and demulsification conditions. Adding endopeptidase Protex 6L during enzyme-assisted aqueous extraction processing (EAEP) of extruded soybean flakes was vital to obtaining emulsions that were easily demulsified with enzymes. Adding salt (up to 1.5 mM NaCl or MgCl₂) during extraction and storing extruded flakes before extraction at 4 and 30 °C for up to 3 months did not affect the stabilities of emulsions recovered from EAEP of soy flour, flakes and extruded flakes. After demulsification, highest free oil yield was obtained with EAEP of extruded flakes, followed by flour and then flakes. The same protease used for the extraction step was used to demulsify the EAEP cream emulsion from extruded full-fat soy flakes at concentrations ranging from 0.03% to 2.50% w/w, incubation times ranging from 2 to 90 min, and temperatures of 25, 50 or 65 °C. Highest free oil recoveries were achieved at high enzyme concentrations, mild temperatures, and short incubation times. Both the nature of enzyme (i.e., protease and phospholipase), added alone or as a cocktail, concentration of enzymes (0.5% vs. 2.5%) and incubation time (1 vs. 3 h), use during the extraction step, and nature of enzyme added for demulsifying affected free oil yield. The free oil recovered from EAEP of extruded flakes contained less phosphorus compared with conventional hexane-extracted oil. The present study identified conditions rendering the emulsion less stable, which is critical to increasing free oil yield recovered during EAEP of soybeans, an environmentally friendly alternative processing method to hexane extraction.