大豆异黄酮微波干法辅助提取及其机理研究

考察大豆异黄酮的微波光波组合无溶剂提取方法,发现微波光波提取干法仅用9.4%的N,N-二甲基甲酰胺DMF作为能量传递介质,功率800 W(微波55%与光波45%)加热6 min后,乙醇萃取得总黄酮.大豆苷元的提取率为0.14%,与相应的常规提取法接近,该法有操作简单快速,成本低,环境污染小等优点.利用高倍荧光显微镜FM...     

油茶茶枯中茶皂素的提取工艺研究

油茶茶枯是南方地区一种常见的加工副产物,含有较高的茶皂素。茶皂素是工业生产中应用广泛的一种表面活性剂,性能优良,但目前茶皂素的提取工艺并不成熟。为了优化油茶茶枯中茶皂素提取的最佳工艺,提高油茶茶枯的利用率,该文以脱脂油茶茶枯粉末为原料,乙醇溶液作为浸提剂,以茶皂素的得率和含量作为提取效果的评价指标,通过单因子实验和正交试验探求油茶茶枯中茶皂素的最佳提取条件。结果表明:以提取时间、3%NaOH添加量、乙醇浓度、料液比、温度和提取次数6个因素作为单因子,对油茶茶枯中茶皂素提取得率和含量进行研究,在单因子实验的基础上进行正交试验得到茶皂素提取的最佳工艺条件为料液比1∶17,乙醇浓度75%,提取温度81℃,提取时间88min,3%NaOH添加量2.5mL(即每10g茶枯粉末中添加0.075g NaOH),提取次数2次。通过论证该结果表明,在最佳的提取条件下,提取得到茶皂素的最高含量为0.54mg·mL-1,得率为21.35%。该实验方法添加了NaOH后,在最佳条件下茶皂素的得率明显提高,对今后优化油茶茶枯中茶皂素的提取工艺具有很好的借鉴意义。     

油茶饼粕中茶皂素的提取及脱色研究

以油茶饼粕为原料,通过有机溶剂进行浸取,研究并确定提取了茶皂素的最佳工艺为乙醇体积分数75%,料液比(g:m l)为1:4,提取时间2 h,提取温度60℃;脱色的最佳条件为pH9,脱色温度60℃,脱色时间1 h,加入H2O220 mL。在此条件下提取的茶皂素得率为16.6%,纯化的茶皂素质量分数达到87.3%。     

微波法从蛹虫草中提取虫草多糖的技术研究

以蛹虫草(Cordycepsmilitaris)为原料,采用微波法对其虫草多糖的提取工艺进行了探讨。通过对其微波功率、提取时间和料水质量比进行正交优化,得到一个最佳提取工艺条件为:微波功率700 W、提取时间2.0 min、料水质量比1:60。通过正交优化的多糖得率为3.78%,比常规热水浸提法高出0.79个百分点。故此,利用微波法从蛹虫草中提取虫草多糖具有得率高、能耗小、操作简单等优点。     

正交设计优化微波辅助测定延胡索叶总生物碱含量

通过微波辅助提取的方式,以延胡索叶总生物碱含量为考察指标,通过单因素试验和正交试验对总生物碱提取方法进行优化。重点考察了微波提取温度、时间、料液比、提取缓冲液pH值等因素对延胡索叶总生物碱得率的影响。各因素对延胡索叶总生物碱提取量的影响大小依次为:提取缓冲液pH值料液比提取温度。其最佳的提取方法为:提取缓冲液pH值为1. 0,料液比1∶100,提取温度60℃,提取时间20 min。在此条件下,叶总生物碱含量为25. 910 mg/g。利用微波辅助提取延胡索叶中总生物碱,不仅耗时短,效率高,而且操作简单、稳定,为延胡索叶总生物碱含量测定提供一定的技术支持。     

塔拉豆荚壳中单宁的提取-微波辅助萃取法

利用微波辅助萃取技术对塔拉单宁进行提取,通过不同的起始温度、加蒸馏水量、提取次数、功率大小等实验并用1%的FeCl3溶液检测提取效果,确定较佳的提取温度、次数、加蒸馏水量和微波辅助萃取仪的功率等因素。结果表明,微波提取塔拉单宁的最佳提取条件为:每次提取加水150~200 mL,微波功率400 w,60℃提取20 min,反复提取4次;再升温至70℃提取20 min 2次,即可提取完全。原料中的单宁含量微波浸提比水浴锅浸提稍高。因此认为用此提取方法可替代水浴浸提法。     

灰树花多糖的提取及抗氧化活性

采用单因素和正交试验法对热水浸提、超声波辅助和微波辅助提取灰树花多糖的工艺进行研究,分别获得了3种方法的最佳条件,并发现微波辅助法最佳,其最优条件为:微波功率800 W、微波时间3 min,浸提2h,多糖得率为13.05％,比热水浸提法提高了51.22％.利用提取的灰树花多糖进行抗氧化性研究,发现灰树花多糖对O2-·和·OH都具有一定的清除作用,且多糖浓度与其对O2-·的清除作用存在量效关系,但不如·OH明显.     

牡丹种壳中丹皮酚和芍药苷的微波提取及含量测定

以牡丹种壳为原料,采用微波辅助提取方法,以芍药苷和丹皮酚得率为指标,利用单因素实验对于影响牡丹种壳中芍药苷和丹皮酚得率的因素进行优化。得到的最佳提取工艺参数为:乙醇提取分数70%,液料比10∶1、微波功率230 W、微波时间10 min,浸泡时间1 h,提取次数1次,牡丹种壳芍药苷和丹皮酚的得率分别为2.88和0.52 mg·g-1。同时,对于选取的微波辅助提取方法的稳定性,回收率和重现性进行验证,结果显示微波辅助提取方法是一个稳定的、可靠的提取方法。     

油茶籽粕中茶皂素的优化提取及抑菌活性的研究

以油茶籽粕为原料,采取超声波辅助乙醇提取法,考察了料液比、浸提时间、超声时间、乙醇体积分数对茶皂素得率的影响,并用响应面优化实验设计得出最优提取条件,优化条件为:料液比1∶7(m/V)、浸提时间93min、超声时间36 min、乙醇体积分数55%,在该条件下茶皂素得率为14.708%。依照此优化方案进行验证实验,结果显示模型可靠性较高,可以较好的预测实际情况。同时茶皂素抑菌效果表明茶皂素对金黄色葡萄球菌有较好的抑菌效果,而对大肠杆菌没有抑菌效果。     

一种提纯粗茶皂素的简易方法

对粗茶皂素的提取纯化工艺进行了研究。以质量分数为70％的粗茶皂素为原料,经2％NaOH溶解、盐酸酸析、95％乙醇溶解、丙酮沉析工艺得到精制茶皂素。检测结果表明,茶皂素质量分数大于95％,提取率大于80％,这种简便易行的工艺得到的茶皂素可作为开发新型植物灭螺剂的原料。     

超临界CO_2和微波辅助萃取艾叶挥发油工艺的研究

通过超临界CO2萃取均匀设计实验和微波辅助萃取艾叶挥发油的正交实验比较,考察影响提取的主要因素,寻求最佳萃取工艺。超临界CO2萃取最佳工艺条件为:萃取压力16MP,萃取温度31℃,CO2流量20kg/h和时间80min,得率3.75%;微波萃取最佳工艺条件为:辐射功率720w,辐射时间200s,溶剂量400mL,洗涤剂量50mL,得率4.85%。水蒸馏法提取率为1.87%。结果表明超临界CO2和水蒸馏法萃取艾叶挥发油品质最好;微波萃取收率最高,但品质较差。     

盾叶薯蓣总皂苷超声提取及动力学

考察了乙醇体积分数、溶剂用量、超声时间、超声功率和超声频率对盾叶薯蓣总皂苷提取率的影响,研究了以体积分数70%乙醇溶液或水作溶剂从盾叶薯蓣中超声提取总皂苷的动力学模型。结果表明,在扩散过程中超声提取薯蓣总皂苷的动力学模型满足非定常扩散方程,相关系数为r=0.95,最佳超声时间为40min。     

微波辐射法合成苄基-2-萘基醚的研究

在微波辐射条件下,以2-萘酚和氯化苄为原料,用氢氧化钠作碱剂,碘化钾作催化剂,以水和N,N-二甲基甲酰胺(DMF)为溶剂合成了苄基-2-萘基醚;采用单因素实验法,考察了反应物的摩尔比、催化剂用量、微波功率、辐射时间等因素对苄基-2-萘基醚产率的影响。实验结果表明:在n(2-萘酚):n(氢氧化钠):n(氯化苄):n(碘化钾)=1:1.1:1:0.018,水7 ml,DMF 25 ml,微波功率320 W和辐射时间75 s的优化条件下,苄基-2-萘基醚的产率可达88.03%。     

Preparation of Silica Nanoparticles Through Microwave-assisted Acid-catalysis

Microwave-assisted synthetic techniques were used to quickly and reproducibly produce silica nanoparticle sols using an acid catalyst with nanoparticle diameters ranging from 30-250 nm by varying the reaction conditions. Through the selection of a microwave compatible solvent, silicic acid precursor, catalyst, and microwave irradiation time, these microwave-assisted methods were capable of overcoming the previously reported shortcomings associated with synthesis of silica nanoparticles using microwave reactors. The siloxane precursor was hydrolyzed using the acid catalyst, HCl. Acetone, a low-tan δ solvent, mediates the condensation reactions and has minimal interaction with the electromagnetic field. Condensation reactions begin when the silicic acid precursor couples with the microwave radiation, leading to silica nanoparticle sol formation. The silica nanoparticles were characterized by dynamic light scattering data and scanning electron microscopy, which show the materials'' morphology and size to be dependent on the reaction conditions. Microwave-assisted reactions produce silica nanoparticles with roughened textured surfaces that are atypical for silica sols produced by Stöber''s methods, which have smooth surfaces.     

桂花精油提取工艺及其抗氧化性的研究

本文以新鲜的金桂花(Osmanthus fragrans Lour)为实验材料,采用微波-蒸馏萃取法提取桂花中的精油。通过改变微波-蒸馏萃取法中的各种工艺参数(匀浆时间、料液比、微波时间),得到相应工艺参数下的桂花精油提取率。采用单因素试验和正交试验,分析提取工艺过程中的参数和提取率得到最优化的桂花精油提取工艺条件,即匀浆时间4min、料液比1∶5、微波时间60s,同时桂花精油提取率为0.85%。根据对桂花精油的理化性质分析可知,实验所得桂花精油样品香气较为纯正,液体呈橘黄色,酸值大约为7.50,酯值大约为18.03,达到精油的国标标准且质量较好。对桂花精油采用磷钼络合物法进行抗氧化性的研究,表明桂花精油的抗氧化活性较强,同时桂花精油的浓度与抗氧化性成正比关系。     

Comparison of Effects of Sublethal Microwave Radiation and Conventional Heating on the Metabolic Activity of Staphylococcus aureus

This study was conducted in an attempt to characterize some of the effects of sublethal microwave radiation on cells of Staphylococcus aureus. Cultures were exposed to microwave radiation for 10, 20, 30, and 40 s. The effects of a conventional heat treatment were also compared by placing flasks containing cultures in a boiling water bath for the amount of time required to reach temperatures equivalent to those found in cultures exposed to microwave radiation. Control, microwave-treated, and conventionally heat-treated cultures were centrifuged, pellets were resuspended in distilled water, and the resulting suspensions were passed through a French pressure cell. Cell lysates and walls were then isolated and assayed for enzymatic activity. Thermonuclease production was also determined at various levels of exposure of cells to microwave radiation. Activities of malate and α-ketoglutarate dehydrogenases, cytochrome oxidase, and cytoplasmic adenosine triphosphatase were higher in microwave-treated cells than in control cells. Membrane adenosine triphosphatase, alkaline phosphatase, and lactate dehydrogenase activities were unaffected when cells were exposed to microwave radiation. The activity of glucose-6-phosphate dehydrogenase was decreased by exposure of cells to microwave radiation. In conventionally heated cells, activities of glucose-6-phosphate and malate dehydrogenases and cytoplasmic adenosine triphosphatase increased activities of α-ketoglutarate and lactate dehydrogenases decreased, and alkaline phosphatase activity remained unaffected. Increased levels of thermonuclease activity were observed when cells were exposed to microwave radiation for 10 or 20 s. Data indicate that microwave radiation affects S. aureus in a manner which cannot be explained solely by thermal effects.     

利用微波固定组织的收缩率

目的探讨利用微波辐射固定、微波辐射与固定液结合固定组织的收缩程度。方法将组织分成40组,用一定强度的微波辐射或一定强度的微波辐射与不同固定液结合方法固定动物组织,并制做石蜡组织切片和HE染色,在此过程中测定各步骤前后的组织块体积,计算出收缩率。结果与结论一定强度的微波辐射和一些微波辐射与固定液结合方法固定的组织收缩率低,这些组织的切片具有细胞质均匀,染色鲜艳,细胞核大而清晰的良好效果。     

Preparative separation of the saponin lancemaside a from Codonopsis lanceolata by centrifugal partition chromatography

Introduction. Lancemaside A is a saponin that inhibits decreases in blood testosterone level and thus prevents or ameliorates symptoms associated with male climacteric disorder. Our initial attempt to preparative isolation of lancemaside A from the saponin fraction of Codonopsis lanceolata roots by a preparative HPLC did not give a clear result. Objective. To develop a simple and efficient method for the preparative isolation of lancemaside A from the hot water extract of C. lanceolata roots using centrifugal partition chromatography (CPC). Methodology. The saponin fraction obtained from the hot water extract of C. lanceolata roots was used as the sample for preparative‐scale separation of lancemasides by CPC using n‐hexane:n‐butanol:methanol:0.1% aqueous formic acid (3:4:1:6, v/v) as the two‐phase solvent system. The upper phase (organic phase) of the two‐phase solvent system was used as the mobile phase, and 0.5 g of saponin fraction was applied for separation by CPC. Each fraction that was separated by CPC was analysed by HPLC, and the fractions containing each of the separated compounds were pooled together, and then were purified by simple preparative HPLC. Results. The demonstrated separation sequence, hot water extraction, DIAION HP‐20 column chromatography, CPC and preparative HPLC, yielded lancemaside A, foetidissimoside A and astersaponin Hb in their pure forms. Conclusion. The simple and efficient method for the preparative isolation of lancemaside A along with two other saponins, foetidissimoside A and astersaponin Hb, from the saponin fraction of C. lanceolata was established using CPC.     

高强度微波辐射对Wistar大鼠血清SOD、HSP70和肝脏MDA、Mit肿胀的影响

研究200 mW/cm2连续10 min的高强度微波辐射条件下对Wistar大鼠氧化应激和肝脏的影响,与空白组相比较,高强度微波辐射对血清中SOD含量的影响十分显著( P <0.05),呈现出距离辐射时间越短,SOD含量越低的现象( P <0.01);同样,高强度微波辐射显示出在辐射初期对血清MDA和HSP70含量的明显提高( P <0.01);线粒体损伤明显( P <0.05),且无明显改善( P >0.05).表明高强度微波辐射(200 mW/cm2)能导致雌性Wistar大鼠氧化应激加强和肝脏损伤.