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1.
高效液相色谱测定血清中的非胆因醇甾醇   总被引:2,自引:0,他引:2  
本文介绍一种用高效液相色谱同时测定血清中24-脱氢胆固醇、7-烯胆甾烷醇、菜油甾醇、胆甾烷醇和β-谷甾醇的方法。血清加内标(6-氯豆甾醇)后用氢氧化钾醇溶液皂化,用正已烷提取其中的各种甾醇,将提出的甾醇衍生为苯氨基甲酸酯,用HPLC分离测定。本法样品处理简单,色谱分析时间短,批内和批间变异系数分别为2.2~3.8%和3.3~6.7%。本文也首报告我国成年人血清非胆固醇甾醇水平,5种甾醇血清深度的总  相似文献   

2.
植物甾醇.甾烷醇在自然界广泛分布,以游离型、脂肪酸酯或糖苷形式存在。植物甾醇.甾烷醇能抑制小肠内胆固醇的吸收,具有降低血清胆固醇的作用。由于其来源于天然植物,且吸收率很低,因此具有很高的安全性。本文对植物甾醇.甾烷醇的降血清胆固醇作用做一综述。  相似文献   

3.
疏花毛萼香茶菜中一新的对映-贝壳杉烷型二萜   总被引:1,自引:0,他引:1  
从疏花毛萼香茶菜(Isodon eriocalyx var.laxiflora)叶中分离得到一新的对映-贝壳杉烷型二萜,命名为疏花丁素(1),通过波谱方法鉴定了它的结构。此外,还分离得到6个已知对映-贝壳杉烷型二萜化合物:疏花甲素(2),毛萼晶A-C(3-5)和Q(6),毛萼乙素(7),以及cirsimaritin(8)和2α-羟基乌索酸(9)。  相似文献   

4.
倒心盾翅藤的化学成分研究   总被引:4,自引:0,他引:4  
从药用植物倒心盾翅藤(Aspidopterys obcordata Hemsl.)中首次分离得到5个化合物,通过波谱分析分别鉴定为木栓酮(1)、无羁萜-3β-醇(2)、二二烷酸甲酯(3)、10-二九烷醇(4)、豆甾醇(5)和daphnetin-8-glucopyranoside(6)。  相似文献   

5.
四川蜘蛛抱蛋的甾体皂甙   总被引:5,自引:0,他引:5  
从四川蜘蛛抱蛋(Aspidistra sichuanensis K。Y。Lang et Z。Y。Zhu)根状茎中分离得到三个甾体皂甙,经光谱和化学方法分别鉴定为22-甲氧基-5β-呋喃甾烷-1β,3β,4β,5β,26-五羟基26-O-β-D吡喃葡萄糖甙(1),蜘蛛抱蛋皂甙(2)和原蜘蛛抱蛋皂甙(3)。(1)是一个呋喃甾醇型单糖链的新皂甙,(3)是本植物的主要皂甙。  相似文献   

6.
山苦瓜中两个乌苏烷类新三萜   总被引:2,自引:0,他引:2  
从葫芦科植物山苦瓜(Monordicadiocica)干燥块根的浸膏中分得7个纯晶体,其中2个是乌苏烷新化合物;3-氧-苯甲酰-6-酮-乌苏酸和3-氧-苯甲酰-11-酮-乌苏酸,其余为已知物:α-菠甾醇,齐墩果酸,丝石竹皂甙元,常春藤皂甙元和硬脂酸。  相似文献   

7.
研究了胆固醇和三十烷醇对浮萍开花的影响。两种化合物在不影响营养生长的情况下都能显著地促进短日植物Lemnaaequinoctialis6746在长日照条件下的开花。胆固醇促进开花的有效浓度范围为10-8~10-6mol/L,三十烷醇促进开花的有效浓度范围为2.3×10-14~2.3×10-8mol/L。相反,在一定浓度范围内,两种化合物对长日植物L.gibbaG1在长日照条件下的开花则有抑制作用。这些实验结果表明,亲脂化合物能够影响浮萍的开花进程,但是对于长日植物的作用不同于短日植物。  相似文献   

8.
西北蔷薇果实化学成分的研究   总被引:6,自引:0,他引:6  
从西北蔷薇(Rosa davidii Crep.)果实中分得11个化合物,经波谱方法鉴定为:2α,3β,19β-三羟基-齐墩果烷-12-烯-28-酸(1)2α,3β-二羟基-乌苏烷-28(13)-内酯(2)、arjunic acid(3)、蔷薇酸(4)、2α,3β-二羟基乌苏酸(5)、齐墩果酸(6)、山奈素(6)、tiliroside(8)、槲皮素(9)、胡萝卜甙(10)和β-谷甾醇(11)。其中1和2为首次发现的新化合物。  相似文献   

9.
本文研究了柯萨基B3病毒(CoxsackievirusB3)对正常人PBMC白细胞介素一2受体(mIL一2R)表达的影响,结果实验组为89.83±7.03%,对照组为52.5±6.13%,表明CoxsackievirusB3能作用于PBMC,使其mIL一2R表达明显减少(P<0.01),由此影响IL-2发挥正常的生物学功能,如促使T细胞增殖,NK细胞活化等,本文认为mIL-2表达减少可能是CoxsackievirusB组病毒所致心肌炎患者细胞免疫功能异常的原因之一。  相似文献   

10.
云木香化学成分研究Ⅱ   总被引:2,自引:1,他引:1  
从丽江产云木香(SausrealappaC.B.Clarke)根中分离得到的另外7个化合物,它们分别是_孕甾烯醇酮(pregnenolone)(1),β-谷甾醇(β-sitosterol)(2),葫萝卜甙(daucosterol)(3),苯丙素甙(syringin)(4),木质素甙(1-hydroxypinoresinol-1-β-D-glucopyranoside)(5),油酸[(z,z)-9,12-octadecadienoicacid](6)和油酸-1,3-甘油二酯[(z,z)-9,12-octadecadienoicacid-2-hydroxy-1,3-propanedinylester](7).它们的结构通过波谱和化学的方法得到鉴定。其中化合物1作为天然产物首次从植物中分离得到,化合物3,4,5和7为首次从该植物中分离得到。  相似文献   

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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   

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17.
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   

18.
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   

19.
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   

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   

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