首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 406 毫秒
1.
Folin-Ciocalteu比色法测定铜藻中褐藻多酚含量的研究   总被引:1,自引:0,他引:1  
以没食子酸为标准品,使用福林酚(Folin-Ciocalteu)试剂,通过紫外-可见分光光度法,对铜藻中褐藻多酚的含量进行了测定。结果表明,测定波长为760 nm,显色试剂Folin-Ciocalteu的用量为1.25 m L,0.1 g/m L Na2CO3溶液用量为4.0 m L,定容至10 m L,显色温度为30℃,反应时间为60 min,多酚含量在15~50μg/m L范围内与吸光度呈良好线性关系,回归方程为Y=0.0138X+0.0267,R2=0.9993。本测定方法的平均回收率为96.18%,相对标准偏差(RSD)为2.44%。该方法的稳定性、重现性、精密度以及加标回收率的相对标准偏差均符合要求,可用于铜藻中褐藻多酚含量的测定。按照本方法测定铜藻中褐藻多酚的平均含量为17.36 mg/g(RSD=1.25%)。  相似文献   

2.
Folin-Ciocalteu比色法测定桦褐孔菌多酚的条件优化   总被引:2,自引:1,他引:2  
以没食子酸为标准品,通过正交试验和单因素实验研究了Folin-Ciocalteu 比色法测定桦褐孔菌中多酚含量的适宜条件。结果表明,优化后的显色条件为Folin-Ciocalteu试剂用量0.3mL、10% Na2CO3溶液0.6mL,25℃时避光反应30min,于750nm处测定其吸光值。多酚质量浓度在0.0032-0.0256mg/mL范围内与吸光值有良好的线性关系。根据拟合的线性回归方程对桦褐孔菌多酚进行定量测定,野生桦褐孔菌和人工培养桦褐孔菌中多酚含量最高分别为(72.05±0.08)mg/g、(52.76±0.06)mg/g(n=6)。不同加标水平的加标回收率测定实验获得的平均回收率为98.95%,RSD为1.27%。该法测定桦褐孔菌多酚具有快速、准确,稳定性强,重现性好,精密度高的特点,可应用于实际样品的测定。  相似文献   

3.
Folin-ciocalteu比色法测桑叶中多酚含量   总被引:3,自引:0,他引:3  
采用以没食子酸为标准,研究了Folin-ciocalteu比色法测定桑叶中多酚含量的适宜条件。结果表明,桑叶提取液在Folin-ciocalteu试剂2.0 mL、20%Na2CO3溶液5.0 mL、反应温度30℃、反应时间2 h的条件下,测定其760 nm处的吸光值,多酚浓度在10.0~100.0 mg/L范围内与吸光值呈良好的线性关系;稳定性、精密度、重现性和回收率实验的相对标准偏差为0.2969%~2.502%。该法是一种简便、快速、准确测定桑叶多酚含量的可靠方法。  相似文献   

4.
研究了以没食子酸为标准品,采用Folin-Ciocalteu比色法,测定花椒多酚含量的适宜条件。结果表明:当Folin-Ciocalteu试剂与10%Na2CO3溶液之比为1∶2(V∶V),Folin-Ciocalteu试剂体积为4 mL,反应温度为25℃,反应时间为120 min时,多酚含量在1~6μg/mL范围内与吸光值呈良好的线性关系。测定了4种花椒中的多酚含量,四川青花椒多酚含量最高。  相似文献   

5.
分析测定了不同生长时期蜜楝花及果实中吴茱萸生物碱及吴茱萸内酯含量及其积累变化。色谱条件为:色谱柱为Inertsil ODS-3C_(18)柱(4.6×150 mm,5μm),以乙腈-四氢呋喃-水(41∶1∶58)为流动相,流速1.0 mL/min,检测波长225 nm,柱温30℃。蜜楝中吴茱萸内酯在49.65~248.25μg/mL范围内呈良好的线性关系,Y=1955.4X-5577.3(R~2=0.9996),平均加样回收率102.70%,RSD为3.00%(n=6);吴茱萸碱在8.88~88.80μg/mL范围内呈良好的线性关系,Y=89913X+73191(R~2=0.9990),平均加样回收率103.99%,RSD为2.18%(n=6),吴茱萸次碱在8.25~49.49μg/mL范围内呈良好的线性关系,Y=56127X-51856(R~2=0.9990),平均加样回收率103.50%,RSD为1.48%(n=6)。随着发育阶段的推移,蜜楝花、果实中吴茱萸碱、吴茱萸次碱及吴茱萸内酯的含量逐渐增加,在近成熟的果实中三种成分含量最高。研究结果表明,蜜楝果实中生物碱和吴茱萸内酯的含量丰富,可作为提取制备吴茱萸生物碱及吴茱萸内酯成分的一种植物资源,具有很好的开发利用价值。  相似文献   

6.
本文报道了溶石胶囊中威灵仙总皂苷的含量测定方法。用铁线莲皂苷Ⅰ为对照品,采用香草醛一硫酸为显色剂,475nm波长处检测。浓度在22.40~201.60μg/mL范围内呈现良好的线性关系,其回归方程为Y=213.2X-2.311,相关系数R=0.9993,加样回收率为100.31%RSD=1.02%。本方法简便,快速,灵敏,适用于该制剂的质量控制。  相似文献   

7.
建立反相高效液相色谱法(RP-HPLC)测定chiisanoside和chiisanogenin的定量分析方法,利用最优色谱条件对十种中韩五加属植物叶中的三萜chiisanoside和chiisanogenin进行定量分析.研究结果表明,最佳色谱条件为:ODS-C18色谱柱(250mm×4.6mm,5μm);流动相:乙腈-水(55:45);检测波长:205 nm;柱温:40℃;流速:1.0 mL/min.Chiisanoside和chiisanogenin线性范围和回归方程分别为16.5~ 181.5 μg/mL,Y=5498356X-9738(r=0.9995)和4.88~78.0 μg/mL,Y=5753131X-8289 (r=0.9979),加样回收率分别为98.87%(标准偏差为1.14%)和98.83%(标准偏差为0.72%).  相似文献   

8.
HPLC法测定葛花中鸢尾苷的含量   总被引:1,自引:0,他引:1  
目的:测定8个产地葛花中鸢尾苷的含量,建立葛花中鸢尾苷含量测定的HPLC方法。方法:采用GRACEC18(250mm×4.6mm,5μm)色谱柱,流动相为乙腈-水梯度洗脱,流速为0.8mL/min,紫外检测波长为265nm;柱温为室温。结果:鸢尾苷的峰面积(Y)与浓度(X)在11.8~236.4μg/mL范围内具有良好线性关系,Y=34920X-1156.5,r=0.9995(n=7);平均加样回收率为103.66%,RSD〈2%(n=9);测得8批不同产地的葛花药材中鸢尾苷含量在37.00~113.1mg/g。结论:建立了高效液相色谱法测定葛花中鸢尾苷含量的方法,该法准确、可靠,可用于葛花中主要成分鸢尾苷的含量测定;不同产地葛花中均检测到鸢尾苷,但其含量有一定区别。  相似文献   

9.
目的:建立天胡荽属植物的积雪草苷和羟基积雪草苷HPLC含量分析的方法,为开发利用天胡荽属植物药用资源奠定基础。方法:以积雪草苷和羟基积雪草苷为指标成分,采用高效液相色谱法,以Symmetry C18(4.6 mm×250 mm,5μm)为色谱柱;乙腈-水(29∶71,v/v)为流动相;流速0.8 mL/min;柱温30℃;检测波长210 nm,外标法进行测定。结果:积雪草苷的回归方程为:Y=34 958X+154 822 R2=0.999 1(n=8),羟基积雪草苷的回归方程为:Y=114 318X-21 002 R2=0.999 2(n=8),结果表明线性关系与分离度良好,平均加样回收率为99.98%、100.53%,RSD为1.86%、2.31%。结论:该方法稳定性、重复性良好,可做为天胡荽属药用资源的评价方法之一,实验结果为野生与栽培资源的开发与利用奠定了基础。  相似文献   

10.
本文建立了积雪草总苷转化产物中积雪草酸B单葡萄糖苷、羟基积雪草酸单葡萄糖苷和积雪草酸单葡萄糖苷含量的测定方法。采用Agilent 1100 Series高效液相色谱仪,Welch Materials,XB-C18(250 mm×4.60 mm,5μm)色谱柱,流动相为乙腈-4 mmol/Lβ-CD溶液(1~15 min:26∶74;15~45 min:28∶72;45~60 min:29∶71,磷酸调节至pH 2.8)梯度洗脱,流速为1.0 mL/min,柱温为30℃,检测波长为204 nm的方法。积雪草酸B单葡萄糖苷、羟基积雪草酸单葡萄糖苷和积雪草酸单葡萄糖苷依次在0.6~6.0μg、1.24~12.4μg和1.34~13.4μg范围内线性关系良好,Y=335.19X-4.7855(r=0.9999)、Y=303.61X-15.208(0.9998)和Y=281.77X-16.357(0.9999);平均加样回收率(n=6)依次为97.59%、100.19%和100.33%,RSD分别为1.70%、0.91%和0.45%。方法学研究结果表明该方法准确、可靠,适用于积雪草总苷转化产物中积雪草酸B单葡萄糖苷、羟基积雪草酸单葡萄糖苷和积雪草酸单葡萄糖苷的含量测定。  相似文献   

11.
12.
13.
14.
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.  相似文献   

15.
16.
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.  相似文献   

17.
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.  相似文献   

18.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
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  相似文献   

19.
20.
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.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号