加速溶剂提取法提取娑罗子中的七叶皂苷

为了探讨快速溶剂提取法(ASE)提取娑罗子中七叶皂苷的可行性,并比较该方法与回流提取法和超声提取法的优越性。本文以娑罗子中的四种七叶皂苷的提取率为指标,以高效液相色谱法(HPLC)为检测方法,用单因素考察法对加速溶剂提取法从娑罗子中提取七叶皂苷的工艺条件进行优化。结果通过实验我们优选出加速溶剂提取法从娑罗子中提取七叶皂苷的最佳条件,即提取溶剂为70%甲醇,提取温度为100℃,静态提取时间为7 min,提取次数为1次。由此可以定论加速溶剂提取法可以快速、高效地提取娑罗子中的七叶皂苷类化合物。     

不同土壤水分条件对七叶一枝花光合特性及有效成分皂苷含量的影响

采用盆栽土壤水分胁迫试验方法,分析不同土壤水分含量（5．78％～21．32％）对珍稀濒危药用植物七叶一枝花（Parispolyphylla）光合特性和主要有效成分皂苷积累的影响,以期为人工栽培中水分的管理提供依据。结果表明,随着水分胁迫的加剧,叶绿素含量、最大净光合速率（Amax）和光饱和点（LSP）逐渐下降,而光补偿点（LCP）和暗呼吸速率（Rd）逐渐升高;根茎体内总皂苷含量则随土壤水分含量的降低先增加后降低,当土壤含水量为12．44％时皂苷含量最大（11．95％）。可见水分胁迫不利于七叶一枝花的光合作用,但适度水分胁迫可提高其皂苷含量。因此,人工栽培七叶一枝花时,前期需提供较充足水分以满足其营养生长,后期则可进行适当的水分胁迫,以提高皂苷含量。     

千金子不同极性部位对酪氨酸酶活性的影响

测定千金子醇提物不同极性部位对酪氨酸酶活性的影响。以L-酪氨酸为底物,采用比色法测定千金子不同极性部位对酪氨酸酶的抑制率。得到了千金子醇提物的乙酸乙酯相、正丁醇相和水相的半数抑制率(IC50值)分别为0.150 mg/mL,0.813 mg/mL,7.570 mg/mL,并对乙酸乙酯相进一步分离得到七叶内酯,其IC50值0.103 mg/mL。结果表明千金子中起到酪氨酸酶抑制性的物质为七叶内酯,主要分布在乙酸乙酯相中。为千金子中酪氨酸酶抑制性物质的筛选提供科学依据。     

温度对七叶一枝花光合特性及皂苷含量的影响

该研究以珍稀濒危药用植物七叶一枝花(Paris polyphylla)为材料,利用人工气候箱设置3个温度条件,即低温(10℃/16℃)、适温(18℃/24℃)、高温(26℃/32℃),采用盆栽法分析了不同温度条件对七叶一枝花光合特性和主要有效成分皂苷含量的影响。结果表明:(1)适温条件下,七叶一枝花叶绿素含量、最大光合速率、光饱和点、表观量子效率均高于低温和高温处理,而光补偿点、暗呼吸速率则低于两者。(2)适温条件下,七叶一枝花根茎体内皂苷含量最大,达到了4.33%,低温和高温处理下皂苷含量分别只有适温的42.26%和33.49%,氨基酸含量同样表现为适温处理下最大。(3)七叶一枝花有效成分含量与叶片叶绿素含量、光合速率呈显著正相关,而与呼吸速率呈显著负相关,说明温度直接影响植株的光合作用、呼吸作用,进而影响有效成分的积累。温度对七叶一枝花光合特性及有效成分的积累影响显著,22℃左右的平均温度(18℃/24℃)是七叶一枝花栽培的适宜温度,此温度有利于其生长及有效成分的积累,该研究结果为七叶一枝花人工栽培中温度的科学管理提供了依据。     

Aspergillus sp. EA-LJS80的分离及其发酵液提取物七叶皂苷C的生物活性

本研究从陕西留坝紫柏山采集的七叶树Aesculus chinensis根和茎中分离出一株具有高产七叶皂苷C的内生真菌,将其编号为EA-LJS80。利用ITS序列分析鉴定其种属并对其形态进行观察;采用紫外-可见分光光度计进行全波长扫描,确定其最大紫外吸收峰;采用HPLC测定七叶皂苷C的产量;采用滤纸片扩散法研究其发酵液提取物的抑菌活性;采用CCK-8法测定提纯后七叶皂苷对肺腺癌A₅₄₉细胞的增殖抑制率,探究其生物活性。结果显示,该菌株EA-LJS80为曲霉菌属Aspergillus真菌,最大紫外吸收波长为230nm,测得提纯后七叶皂苷C的产量为9.23mg/mL。生物活性实验表明：菌株EA-LJS80的发酵液提取物对大肠杆菌Escherichia coli等4种致病菌有明显的抑菌效果;经CCK-8法测定,提纯后的七叶皂苷对肺腺癌A₅₄₉细胞的增殖有明显的抑制作用。综上所述,菌株EA-LJS80具有产七叶皂苷活性,尤其是七叶皂苷C的产量较高,且其产生的七叶皂苷具有较高的生物活性,这对于改进七叶皂苷生产模式,提高生产效率具有重要意义,同时对于七叶皂苷C的进一步研究有一定的促进作用。     

七叶皂苷钠对一氧化碳中毒迟发性脑病大鼠模型细胞凋亡 及调控凋亡基因表达的影响

目的:探讨七叶皂苷钠对一氧化碳中毒迟发性脑病大鼠模型细胞凋亡及Caspase-3表达的影响。方法:将30只大鼠随机分为正常对照组、一氧化碳中毒迟发性脑病大鼠模型对照组和七叶皂苷钠治疗组,原位末端标记法(TUNEL)检测细胞凋亡,免疫组化法检测Caspase-3的表达。结果:治疗组大鼠脑细胞凋亡率及Caspase-3表达较迟发性脑病对照组显著降低(P<0.01)。结论:七叶皂苷钠对一氧化碳中毒迟发性脑病的脑保护作用机制可能与干预脑细胞凋亡相关基因表达并减少神经细胞凋亡有关。     

七叶皂苷对P-糖蛋白功能的影响

目的:探讨七叶皂苷时P-糖蛋白功能的影响.方法:构建稳定表达P-糖蛋白的LLC-PK1细胞系,以real-time RT-PCR和Western Blotting分析P-糖蛋白基因mRNA和蛋白表达,共聚焦显微镜观察P-糖蛋白细胞定位,流式细胞术检测细胞内罗丹明123荧光强度.结果:(1)P-糖蛋白在LLC-PK1细胞中稳定高表达;(2)转染细胞中P-糖蛋白定位在细胞膜上;(3)七叶皂苷抑制P-糖蛋白功能.细胞内罗丹明123荧光强度增加123%,但其抑制效果是维拉帕米的30%.结论:七叶皂苷抑制P-糖蛋白功能,但其抑制效果弱于维拉帕米.     

多叶重楼遗传多样性的RAPD分析

应用RAPD技术检测了多叶重楼(Paris polyphyfzo)2个变种4个居群的遗传多样性,并与1个凌云重楼(P．cronquistii)居群进行了比较。选择的16个随机引物在5个居群中共检测到246个多态位点。在居群水平上,滇重楼2个居群的多态位点百分比(PP鳓分别为57．43％和54．67%,Shannon指数分别为0．3080和0．2830;七叶一枝花2个居群的PPB分别为56．33％和57．75%,Shannon指数分别为0、3080和0．3293。在变种水平上,滇重楼的PPB为75．14％,Shannon指数为0．3922,遗传分化系数(Gst)为0．3085;七叶一枝花的PPB为80．31％,Shannon指数为0．3992,遗传分化系数(Gst)为0．3726;在种的水平PPB达92．05%,遗传分化系数Gst达0．5151。聚类分析显示滇重楼和七叶一枝花有较近的亲缘关系,而与凌云重楼遗传距离较远。此结果从分子水平上支持了过去将滇重楼和七叶一枝花划分为1个种下2个变种的形态分类观点。     

缘毛紫菀中的4个三萜皂苷

利用溶剂萃取,大孔树脂、硅胶和聚酰胺的色谱法,对缘毛紫菀的正丁醇萃取物的化学成分进行了研究,从中分离得到4个三萜皂苷,经1H-NMR、13C-NMR等现代波谱技术及化学方法分别鉴定为续断皂苷B(1)、臭瓜皂苷A(2)、三褶脉紫菀皂苷A(3)和东风菜皂苷A4(4)。化合物1为首次从该属植物中得到,化合物2、3和4为首次从缘毛紫菀中得到。     

七叶皂苷的药理作用与临床应用

娑罗子为七叶树科植物欧洲七叶树(Aesculus hippocastannum)、日本七叶树(Aesculus turbinata Blume)和中国天师栗(Aesculus Wilsonii Rehd)的果实或种子。欧洲七叶树,又名欧马栗(horse chestnut),其种子和幼枝的外皮可入药,在欧洲应用广泛,早在18世纪即用于解热,19世纪后期可用于治疗痔疮。七叶皂苷是从娑罗子(七叶树种子)中提取的主要活性成分,属于三萜皂苷类药物。它具有抗渗、消肿、改善血液循环、增加静脉张力、抑制胃排空、清除活性氧和抗肿瘤作用。临床上可广泛应用于慢性静脉功能不全,痔疮、水肿、哮喘等。本文对七叶皂苷的药理作用及其临床应用进行综述。     

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.