AB-8大孔树脂吸附分离红花桑寄生总黄酮的影响因子研究

AB-8大孔吸附树脂对红花桑寄生总黄酮静态吸附和动态洗脱的效果,受提取液质量浓度、pH值及环境温度、振速以及洗脱剂乙醇浓度、流速等因素影响。试验表明,提取液质量浓度和pH值对AB-8树脂的吸附效果有显著影响,其吸附分离总黄酮的工艺条件为:浓度为1.2~2.0 mg/ml、pH 3.0~4.0的红花桑寄生提取液,置于摇床上,于室温条件下振荡(振速160 r/min)吸附2~3 h,然后用5倍于树脂体积(5BV)的50%乙醇以1.5 ml/min流速进行柱上动态解吸。AB-8树脂对红花桑寄生总黄酮的饱和吸附量可达29.0 mg/g,动态洗脱率达95.0%,获得产品中黄酮纯度为46.0%,得率为5.5%。     

大孔吸附树脂分离纯化银杏中种皮总黄酮

通过静态吸附、静态解吸及吸附动力学研究,对比分析了AB-8、DM-130、S-8等三种大孔吸附树脂对银杏中种皮提取液中总黄酮的分离纯化效果,并且考察和优化了AB-8和DM-130分离纯化银杏中种皮总黄酮的工艺条件.结果表明,弱极性树脂AB-8和DM-130的吸附率分别为87.72%和86.29%、解吸率为97.52%和92.20%,是性能良好的总黄酮吸附剂; 二种树脂的静态吸附曲线变化趋势一致,6 h左右达到吸附平衡,最佳吸附条件:吸附液pH=3.0,树脂用量:吸附液=1:20,吸附温度40 ℃,洗脱剂70%乙醇;动态解吸研究显示,7倍和9倍体积洗脱剂可分别将AB-8与DM-130树脂柱吸附的总黄酮基本洗脱.在优化的工艺条件下,AB-8大孔树脂纯化可使提取物中总黄酮含量达16.3%.     

AB-8树脂对珍珠菜总黄酮的吸附性能研究

目的：考察AB-8树脂对珍珠菜提取液中总黄酮的吸附、解吸附性能及影响因素。方法：采用紫外分光光度法测定总黄酮的含量,分别考察了样品液浓度、pH值和流速对AB-8树脂吸附珍珠菜总黄酮的影响,以及洗脱剂乙醇浓度和流速对解吸附效果的影响。结果：样品液总黄酮浓度10mg／mL、pH值5．07、流速1．0mL／min时,AB-8树脂对珍珠菜总黄酮的吸附效果较好;洗脱剂为70％乙醇,流速1．5mL／min时,洗脱完全,固体总黄酮含量较高。结论：在上述条件下,AB-8树脂可用于珍珠菜提取液中总黄酮的分离纯化。     

大孔树脂吸附法提纯苦楝素的研究

研究了大孔树脂吸附法从苦楝树皮的提取液中提纯苦楝素的工艺条件及参数,并筛选出较为理想的大孔吸附树脂。研究结果表明,S-8型吸附树脂的静态饱和吸附量明显大于AB-8型和NKA-9型。该树脂吸附提纯苦楝素的优化吸附条件为吸附温度40℃,溶液pH值8．0,上柱液质量浓度9．127mg／mL,溶液流速2BV／h;优化的解吸条件为：洗脱剂为70％乙醇-水溶液,溶液流速1BV／h,洗脱剂用量为8倍量树脂体积。在优化条件下,可以得到含量达75．2％的苦楝素提取物,表明S-8树脂对苦楝素有良好的吸附选择性。     

大孔吸附树脂对红车轴草异黄酮吸附分离特性的研究

通过比较14种大孔吸附树脂对红车轴草异黄酮的吸附率和解吸率,筛选出适合红车轴草异黄酮分离的树脂,并对其动态吸附特性进行研究。结果表明,AB-8树脂对红车轴草异黄酮不仅吸附量大,而且解吸率高,适合红车轴草异黄酮的分离富集。AB-8树脂分离红车轴草异黄酮的工艺参数为:上柱液浓度0.79~1.11 mg/mL,pH 4.24,流速2 BV/h。以4倍树脂床体积的80%乙醇以2 BV/h流速进行洗脱,可基本上将红车轴草异黄酮从树脂上解吸下来,异黄酮回收率为93.72%。     

大孔树脂吸附分离烟草绿原酸的研究

通过比较8种大孔吸附树脂对烟草绿原酸的吸附分离性能,筛选出适合分离烟草绿原酸的树脂,并对其动态吸附特性进行研究.结果表明,XDA-1树脂对烟草绿原酸不仅吸附量大,而且解吸率高,适合烟草绿原酸的分离富集.该树脂吸附分离烟草绿原酸的工艺参数为:上柱液浓度3.5 mg/mL,pH 3.0,流速3倍柱床体积/h;以6倍柱床体积的40%乙醇进行洗脱,解吸附效果最佳,绿原酸总回收率为80.06%,初步吸附分离得到的产品中绿原酸含量为39.20 g/100 g.     

AB-8大孔树脂纯化欧洲鳞毛蕨总黄酮的研究

目的:对AB-8大孔吸附树脂对欧洲鳞毛蕨总黄酮的纯化工艺条件进行了系统的研究。方法:采用静态和动态的吸附-解吸实验,利用紫外可见分光光度计测量欧洲鳞毛蕨总黄酮的含量,研究不同的工艺条件对总黄酮纯化的影响。结果:AB-8大孔树脂对欧洲鳞毛蕨总黄酮的饱和吸附量是25.53mg/g,洗脱率达到98.3%,提取液的pH值对树脂的吸附能力有很大的影响,当pH值为4.08(原液pH值)时树脂吸附能力达到最大。采用0.5mg/mL流速上样,1.2BV 30%和1BV 50%乙醇1.0 mg/mL流速洗脱可较好的分离纯化欧洲鳞毛蕨总黄酮。结论:AB-8大孔树脂是欧洲鳞毛蕨总黄酮纯化的理想吸附剂。     

大孔吸附树脂分离纯化番石榴叶总黄酮的研究

考察大孔吸附树脂吸附分离番石榴叶总黄酮的工艺条件.以静态饱和吸附量、静态洗脱率、动态饱和吸附量、动态洗脱率为考察指标,比较了D101、AB-8两种大孔树脂分离纯化番石榴叶总黄酮的优劣.又以总黄酮回收率为指标,对最佳树脂吸附工艺参数进行了研究.在考察的2种树脂中,AB-8型树脂最适于番石榴叶总黄酮的分离纯化,其工艺条件为:4倍树脂体积50%乙醇洗脱,速度2mL/min.树脂可重复使用4次.其平均总黄酮回收率为87.47%.所得总黄酮纯度为74.03%     

桑椹中黄酮类物质的大孔树脂纯化工艺

以桑椹中黄酮类物质的吸附量和解吸率为指标,对比分析HZ-801、HZ-816、HZ-818等12种大孔吸附树脂对桑椹提取液的分离纯化效果,优选出最佳树脂HZ-801并通过对上样液pH、上样液质量浓度、上样量、吸附流速、洗脱剂质量浓度、洗脱剂用量、洗脱流速等影响因素的考察,确定最优工艺:吸附阶段上样液pH=4,上样液质量浓度0.45mg/mL,上样量420mL,吸附流速120mL/h,动态吸附量(干树脂)25.34mg/g,吸附率84.25%;洗脱阶段的洗脱剂体积分数为60%乙醇,洗脱剂用量270mL,洗脱流速120mL/h。此优化工艺条件下的洗脱率为85.78%,总黄酮纯度从23.64%提高到82.36%。     

吸附树脂AB—8对甘草酸的吸附性能及其在提取纯化中的应用

考察了大孔吸附树脂AB-8对甘草酸的吸附性能和原液浓度pH值、流速、洗脱剂的种类对树脂吸附性能的影响。结果表明,AB-8树脂对甘草酸吸附量高,易于洗脱,分离效果较好,回收率较一般方法高,达70％～80％,纯度达90％以上。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.