鹰嘴豆芽素A糖苷类衍生物的合成及其结构表征

为了改善鹰嘴豆芽素A代谢稳定性,提高其生物利用度,本文以乙酰溴代糖和鹰嘴豆芽素A为原料,采用相转移催化法在鹰嘴豆芽素A 7位羟基处引入糖苷,合成12个鹰嘴豆芽素A糖苷类衍生物,方法简单,条件温和,产率较高。产物结构通过1H NMR、13C NMR、IR和ESI-MS分析确认,为进一步对其进行生物活性研究奠定了基础。     

萌芽鹰嘴豆主要异黄酮变化规律及分布研究

目的：考察鹰嘴豆萌芽过程中鹰嘴豆芽素A和芒柄花素含量的变化规律及豆芽不同部位2种成分含量的差异。方法：将鹰嘴豆在22 ℃萌芽,分别于萌芽的0、1、2、3、5、7、9d取样品测定鹰嘴豆芽素A和芒柄花素含量,取萌芽7d鹰嘴豆,分别取其子叶、胚根和胚芽测定上述2种成分含量,分析2种成分含量变化规律和豆芽不同部位含量差异。 结果：鹰嘴豆芽素A 和芒柄花素含量自发芽后呈现不断增长的趋势,第3～7d增长迅速、第7～9d后增速放缓,不同部位含量大小依次为胚根＞胚芽＞子叶。结论：鹰嘴豆萌芽过程中鹰嘴豆芽素A和芒柄花素含量呈不断上升趋势,成分主要集中在胚根和胚芽中。     

鹰嘴豆芽素A对耐甲氧西林金黄色葡萄球菌外排系统的抑制作用

【目的】MRSA外排系统是其对多种药物耐药性的主要原因,为此研究鹰嘴豆芽素A对MRSA外排系统的抑制作用。【方法】以MRSA41577为供试菌株,通过二倍稀释法、双平板法和荧光分光光度法测定鹰嘴豆芽素A对MRSA41577的抑制作用及其对外排系统的影响;通过RT-PCR检测加药前后MRSA41577外排蛋白norA的表达量;SDS-PAGE检测加药前后与MRSA41577外排相关蛋白的变化,并用液相色谱质谱仪进行鉴定确认。【结果】鹰嘴豆芽素A本身无抑菌活性,但鹰嘴豆芽素A和环丙沙星联合作用后,MRSA41577对环丙沙星的敏感性显著提高,其中40μg/mL的鹰嘴豆芽素A能使环丙沙星对MRSA41577的MIC从64μg/mL降低到8μg/mL,且作用强度与药物浓度呈正相关。经鹰嘴豆芽素A处理MRSA41577后,菌体内环丙沙星的蓄积量随着药物处理时间的增加而增加,在处理15min时与对照组相比,菌体内环丙沙星蓄积量增加了83%(P﹤0.01),与阳性对照利血平的作用效果相当。鹰嘴豆芽素A能降低MRSA41577的norA表达量,与对照组相比,鹰嘴豆芽素A和环丙沙星作用MRSA41577 16h后,norA的相对表达量降低了65%,其抑制效果优于阳性对照利血平的48%。SDS-PAGE电泳结果显示,鹰嘴豆芽素A作用MRSA4157716h后,与对照组相比菌体的蛋白谱带发生了明显的变化,其中与外排系统相关的蛋白除norA蛋白明显减少外,ABC转运体ATP结合蛋白也明显减少。【结论】鹰嘴豆芽素A是MRSA41577的外排泵抑制剂,其作用机制是通过降低MRSA41577菌体内norA基因的表达量,进而减少norA蛋白的表达量,来抑制MRSA41577对环丙沙星等药物的排出而恢复其对药物的敏感性。     

离子液体微波辅助提取降香檀叶中鹰嘴豆芽素A和染料木素

以降香黄檀可再生资源——叶子为原料,利用离子液体微波辅助提取技术对鹰嘴豆芽素A和染料木素进行提取。通过单因素实验,3因素3水平的BBD(Box Behnken design)实验,对提取条件进行优化,确定了离子液体微波辅助提取降香檀叶中鹰嘴豆芽素A(biochanin A)和染料木素(genistein)的最佳提取工艺条件：1.00 mol·L^-1［C₄MIM］Br,提取温度为56℃,液固比18∶1,提取时间为11 min,提取功率300 W。在最佳提取条件下,鹰嘴豆芽素A和染料木素平均提取率分别可达1.598和0.939 mg·g^-1。     

花梨木叶中鹰嘴豆芽素A的提取工艺研究

以花梨木的可再生资源—叶子为原料,利用微波辅助酶提取技术进行提取,在单因素试验的基础上对提取条件进行了考察,根据BBD(Box-Behnken design)实验设计原理,采用3因素3水平的响应面分析法,以花梨木叶子中主要异黄酮鹰嘴豆芽素A(biochanin A)为指标,对提取过程进行优化,得到最佳工艺参数为:提取时间15 min,微波辐射功率300 W,提取温度34℃,pH值5.2,酶的加入量3.5 mg.g-1。在最佳提取条件下,鹰嘴豆芽素A的提取率可达1.579 mg.g-1。     

鹰嘴豆种质资源对Ascochyta rabiei的抗性评价及遗传多态性分析

以25 个鹰嘴豆品系为试验材料,通过叶面喷雾的方式进行Ascochyta rabiei菌悬液室内外人工接种,评价不同鹰嘴豆种质资源的抗病性;同时利用RAPD方法进行基因型鉴定,采用NTSYSpc 2.10t软件对分子标记结果进行遗传相似性的统计分析并建立各品系间的亲缘关系聚类图,探讨不同鹰嘴豆品系对A.rabiei抗性与遗传多态性间的关系。通过室内和田间鹰嘴豆抗A.rabiei鉴定结果综合分析表明：在25个鹰嘴豆供试品系中,“系选 03”和“216”品系均表现出稳定抗性特性;北园春品系表现出稳定中抗特性。通过RAPD多态性引物对这25 个供试品系进行PCR扩增,共获得129 个扩增条带,其中多态性条带共有67 条,多态性比例达51.94%,遗传相似系数为0.3731-0.9254。结合抗病性和遗传多态性,经方差分析表明,本研究所采用的鹰嘴豆品系对A.rabiei的抗性强弱与其遗传相似性之间无显著相关性。     

苏木化学成分的研究(Ⅰ)

从苏木(Caesalpinia sappan L.)70%乙醇提取物分离得到了8个化合物,利用现代波谱学方法鉴定其结构分别为5,7-二羟基-4′-甲氧基二氢异黄酮(1),鹰嘴豆芽素A(2),3,7,3′,4′-Tetrahydroxyflavanone(3),(αR)-α,3,4,2′,4′-Pentahydroxydihydrochalcone(4),Sappanone B(5),7,3′,4′?三羟基二氢异黄酮(6),7,3′,4′?三羟基二氢黄酮(7),7,3′,4′-三羟基异黄酮(8)。其中化合物1~4、6~8为首次从该属植物中分得的。     

鹰嘴豆素A对病理脱发模型小鼠毛发生长影响的初步研究

本文初步研究了鹰嘴豆素A对毛发生长的影响和机制。实验分为空白对照组、脱发模型组、鹰嘴豆素A组和米诺地尔组。以睾酮诱导的C57BL/6小鼠为脱发模型,通过对比空白对照组与其毛长、毛重以及皮肤中毛囊的差异性来判断脱发模型是否构建成功,对比两组之间激素含量的差异以研究此脱发模型对激素的影响;对比鹰嘴豆素A组与脱发模型组毛长、毛重、皮肤中毛囊和血液中激素含量的差异性来研究鹰嘴豆素A对脱发小鼠毛发生长情况和激素水平的影响;利用体外微量酶反应体系研究鹰嘴豆素A对5α-还原酶活性的抑制作用。结果显示,与空白对照组相比,脱发模型组小鼠毛长、毛重、毛囊数目显著减少,血液中雄激素含量显著升高;与脱发模型组相比,鹰嘴豆素A组小鼠毛长、毛重、毛囊数目显著增加,血液中雄激素含量显著降低。鹰嘴豆素A具有一定抑制5α-还原酶活性,相对抑制率达到50%的浓度(IC50)为94.45±6.92μmol/L。结果表明脱发模型构建成功,鹰嘴豆素A对毛发生长具有一定的促进作用,其机制可能与睾酮的转化过程或抑制5α-还原酶活性有关。     

鹰嘴豆铁蛋白提取工艺优化研究

本研究以鹰嘴豆为原料,研究了缓冲液种类、缓冲液pH值、料液比、盐析盐种类、盐浓度等因素对鹰嘴豆铁蛋白提取率、总蛋白提取率及干重的影响。在单因素实验的基础上,以L9(34)正交实验方法优化鹰嘴豆铁蛋白提取工艺。结果表明:各因素对鹰嘴豆铁蛋白提取率的影响顺序依次为:料液比盐浓度温度pH。最优提取工艺为:料液比1∶4,浓度为70 mmol/L MgCl2盐析,温度50℃,KH2PO4-NaOH缓冲液pH 7.5,最优提取率为0.002643%。     

萆薢类药材的HPLC指纹图谱研究

应用HPLC方法测定了薯蓣属根状茎组10种1亚种1变种植物23个样本,建立了萆薢类药材总皂苷元粗提物的HPLC指纹图谱.色谱柱为Zorbax Eclipse XDB-C_(18)柱(4.6×250 mm,5 μm),流动相为乙腈-水,柱温30℃,检测波长为203 nm.结果表明,用上述条件所建立的指纹图谱共标示出7个共有峰,且可较全面地反映萆薢类药材的皂苷元类成分,为萆薢类药材薯蓣属根状茎组植物鉴别及质量控制提供一种方法.     

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.