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1.
为优化超声波辅助提取细柱五加叶中色素条件,并探索其细胞毒性和抗炎活性,研究考察提取次数、料液比、提取时间、提取温度及超声波功率5个因素对细柱五加叶中色素提取率的影响,并运用响应面法对其超声提取工艺条件进行优化,得到其最佳提取条件为:在超声波频率为40 kHz、功率为130 W、液料比为1:10、提取温度为64℃的条件下,用95%乙醇连续提取3次,每次27 min,其理论提取率为0.373 7%,实际提取率为0.370 8%;通过体外试验对该法提取的总色素的抗炎活性和细胞毒性进行初步研究,发现其对LPS诱导RAW 264.7细胞所产生的NO具有较好抑制能力但在一定剂量范围内具有细胞毒性。  相似文献   

2.
在超声辅助条件下,提取"对叶大戟"中的化学成分,经减压浓缩后得到浸膏,利用大孔树脂色谱法、凝胶色谱法对萃取物进行梯度洗脱,最后用1 H NMR、13 C NMR、ESI-MS对所得的产物进行结构鉴定.结果表明从"对叶大戟"萃取物中提取出了一种黄酮类化合物:山奈酚-3-O-β-D葡萄糖醛酸苷.  相似文献   

3.
以连云港花果山山楂叶为原料,以总黄酮提取率为衡量提取工艺的指标。通过单因素和正交实验设计优化了超声辅助提取山楂叶黄酮的工艺,确定了从山楂叶中提取黄酮的最佳工艺条件:乙醇浓度70%,液料比20:1 m L/g,超声温度70℃,超声时间40 min,提取3次,山楂叶黄酮提取率为2.53%。此外,采用琼脂平板扩散抑菌法和DPPH·法研究了连云港山楂叶黄酮对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌的抑制作用以及抗氧化效应,结果表明山楂叶黄酮具有明显抑菌活性和清除DPPH·的能力。  相似文献   

4.
超声对益母草茎内组织损伤与总碱产率关系研究   总被引:5,自引:0,他引:5  
利用扫描电镜、分光光度计、层析法等仪器和测试分析手段,探讨了超声提取和回流、浸泡提取益母草中总生物碱后各种提取法所得总生物碱成分的产率、层析图和益母草茎内形态结构、显微结构的变化.结果表明,超声提取可损伤益母草茎内组织细胞,促使益母草总生物碱成分快速提取,与回流、浸泡提取比较,超声提取可提高益母草总生物碱成分的产率,缩短提取时间,且益母草总生物碱成分结构无变化,茎内损伤与超声提取时间及成分产率有关。  相似文献   

5.
试验研究了不同种预处理方式,对超声波法提取库拉索芦荟根、茎、叶总黄酮的影响,用分光光度法测定了其总黄酮含量.实验表明,不同种预处理方式对芦荟根、茎、叶总黄酮提取的影响不同:芦荟根乙醇浸泡24h超声提取黄酮的量高于未浸泡直接超声所得黄酮的量;芦荟茎浸泡24h超声得黄酮的量与直接超声得黄酮的量基本相同;叶浸泡24h超声得黄酮的量低于直接超声所得黄酮的量,库拉索芦荟的根、叶中所含黄酮的量远高于茎.  相似文献   

6.
以乙醇为提取溶剂,选用超声波辅助法提取南非叶中的多酚.以多酚提取率为评价指标,对液料比、乙醇体积分数、超声时间和超声温度进行单因素实验,并通过响应面分析,创建多元二次回归模型,确定了最佳的工艺条件.结果表明超声温度是影响南非叶多酚提取率的最显著因素,乙醇体积分数和超声温度间的交互作用对提取率影响差异最显著.南非叶多酚的最佳提取条件为:液料比为30 mL/g,乙醇体积分数为65%,超声时间31 min和超声温度为59℃,在此条件下获得提取率实际值为20.33 mg/g,相比理论预测值20.36 mg/g,算得相对误差仅0.15%,表明此模型具有较好可靠性与准确性,为南非叶多酚的提取及开发提供了新的研究方向.  相似文献   

7.
为了解茶梅茎叶中挥发油的化学成分,采用水蒸汽蒸馏法分别提取茶梅茎、茶梅叶中的挥发油,用气相色谱—质谱联用法分析和鉴定其化学成分,从茶梅茎、茶梅叶挥发油中分别确定出27,37种成分,在挥发油中的质量分数分别为0.990 40,0.963 54。其中,丁香酚为茶梅茎、茶梅叶挥发油主要成分,丁香酚在茶梅茎挥发油中的质量分数为0.922 23,在茶梅叶挥发油中的质量分数为0.913 28。  相似文献   

8.
目的探讨3种不同提取方法的梅花鹿茸多肽对小鼠成骨细胞MC3T3-E1细胞生物学活性的影响.方法分别采用匀浆法、匀浆裂解法、匀浆超声法在新鲜梅花鹿茸中提取梅花鹿茸多肽(velvet antler polypeptiddes,VAP),用BCA法对梅花鹿茸多肽蛋白质浓度进行分析,培养MC3T3-E1细胞,采用MTT法检测3种提取方法获得的梅花鹿茸多肽对细胞增殖率的影响,利用茜素红染色对MC3T3-E1细胞进行矿化定量测定.结果匀浆法多肽得率9.08%;匀浆裂解法多肽得率15.56%;匀浆超声法多肽得率13.38%;鹿茸多肽能明显促进MC3T3-E1细胞的增殖,并且匀浆超声法的增殖作用最强.钙沉积物的比较表明:与对照组比较,匀浆法、匀浆裂解法和匀浆超声法对MC3T3-E1细胞中的矿化现象呈现递增趋势.结论 3种提取方法综合比较,采用匀浆超声破碎方法提取梅花鹿茸多肽,不仅可以节约时间,而且提高了梅花鹿茸多肽的提取量,是较为理想的鹿茸多肽提取方式,并且能明显地促进MC3T3-E1细胞的增殖和矿化.  相似文献   

9.
中药甘草水溶性多糖的提取与测定   总被引:3,自引:0,他引:3  
对中药甘草水溶性多糖的提取工艺进行了研究,并探讨了脱蛋白的优选方案.正交试验表明,水煎煮法提取水溶性甘草多糖的最佳工艺条件为:料液比为1:8,温度控制在90℃,提取时间为3h;超声法提取水溶性甘草多糖的最佳工艺条件为:料液比为1:8,超声功率为100W,提取时间15min.脱蛋白的最优方法为:三氯乙酸-Sevag法.结果表明,在最佳提取工艺条件下,超声法提取水溶性甘草多糖的量是水煎煮法的2.77倍,说明超声法是从甘草中提取水溶性多糖的一种较好的方法.  相似文献   

10.
以金叶女贞叶为材料,寻找其中总黄酮的超声提取的最佳条件.以总黄酮含量为考察指标,在单因素实验的基础上,采用L9(34)正交实验,超声提取研究了乙醇浓度、超声提取时间、超声功率、超声温度对提取金叶女贞叶中总黄酮的影响.从实验结果分析,影响超声提取效果的因素为乙醇浓度超声时间提取功率提取温度,结果表明粒度为40目,乙醇浓度为65%,超声时间为75 min,超声功率为400 W,提取温度为50℃时总黄酮得率最高.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

18.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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