黄花败酱黄酮类化合物的提取与分析

用70％乙醇提取黄花败酱黄酮类化合物,得到粗黄酮,经聚酰胺纯化,得到精制黄酮。结果表明：黄花败酱干粉中总黄酮含量为2．35％,粗黄酮、精制黄酮中黄酮含量分别为8．81％和21．39％。黄花败黄酮类化合物主要是黄酮和黄酮醇两类,其中含有芦丁成分。     

棘豆属植物Oxytropis pseudoglandulosa化学成分研究

从棘豆属植物O.pseudoglandulosa的地上部分中分离得到2个芳香性酰胺类化合物和3个黄酮类化合物,经波谱学方法鉴定为N-苯乙基苯甲酰胺(N-phenylethyl-Benzamide,1),N-(2-羟基,2-苯乙基)肉桂酰胺(N-(2-hydroxy-2-phenylethyl)cinnamamide,2),5-羟基,7-甲氧基二氢黄酮(5-hydroxy-7-methoxyflavanone,3),5-羟基,7-甲氧基黄酮(5-hydroxy-7-methoxyttavone,4),7-羟基二氢黄酮(7-hydroxyflavanone,5).其中3个黄酮类化合物均为首次从该植物中分得.     

芙蓉菊中黄酮类化学成分的研究

从菊科芙蓉菊属植物芙蓉菊的全草中分离得到六个黄酮类化合物,经光谱分析鉴定为:5,7-二羟基-3',4',5'-三甲氧基黄酮(1),粗毛豚草素(2),3',4'-二甲氧基-5',5,7,-三羟基黄酮(3),万寿菊黄索-3,6,7-三甲醚(4),石杉黄素(5),槲皮素-7-O-β-D.葡萄糖苷(6).这些黄酮类化合物皆为首次从该属植物中分离得到.     

益智茎叶中黄酮类化学成分研究

对益智茎叶中黄酮类化学成分进行研究,采用多种色谱方法进行分离纯化,运用多种谱学方法并结合理化性质对分离得到的化合物进行结构鉴定。结果从益智茎叶95%乙醇提取物中共分离得到11个黄酮类化合物,其中包括8个黄酮类化合物,分别鉴定为:良姜素(izalpinin)(1)、杨芽黄素(tectochrysin)(2)、白杨素(chrysin)(3)、芹菜素(apigenin)(4)、刺槐素(acacetin)(5)、5-羟基-4',7-二甲氧黄酮(5-hydroxy-4',7-dimethoxyflavone)(6)、山奈酚-4'-O-甲醚(kaempferol-4'-O-methylether)(7)、5,7,4'-三甲氧基黄酮(5,7,4'-trimethoxyflavone)(8)和3个二氢黄酮类化合物,分别鉴定为:乔松素(pinocembrin)(9)、球松素(pinostrobin)(10)和二氢山萘酚(dihydrokaempferol)(11)。所有化合物均为首次从该植物茎叶中分离得到,其中化合物6、8和10为首次从该属植物中分离得到。     

青橄榄总黄酮提取工艺及部分性质研究

目的：以青橄榄为原料研究提取分离黄酮类化合物的方法与条件,建立最佳提取工艺。方法：采用醇提法,通过单因素试验考察浸提溶剂浓度、浸提温度、浸提时间等三个因素对青橄榄中黄酮类化合物提取效率的影响,同时采用不同显色方法及紫外、红外测定其性质。结果：在单因素的基础上,通过正交试验L9（34）,得三因素中乙醇浓度的影响最大,并初步判断了提取物的性质。结论：青橄榄中黄酮类化合物最佳提取工艺为：乙醇浓度60%,浸提温度70℃,浸提时间120min,提取率达19.87mg/g。另外初步判断提取物中可能含有查尔酮类化合物。     

微波辅助提取荔枝核黄酮类化合物及其抗氧化性研究

研究微波辅助法提取荔枝核黄酮类化合物的工艺,考察了提取溶剂、微波功率、溶剂用量、辐射时间、提取次数等因素对提取的影响。通过正交实验确定最佳的提取参数为:60%乙醇作为提取溶剂,微波功率700 W,料液比1∶25,辐射时间150 s,提取一次。在此优化条件下用微波辅助,黄酮类化合物的得率为6.86%,提取物中黄酮含量达到36.7%。抗氧化性研究表明荔枝核黄酮类化合物有良好的抗氧化活性,能有效清除羟基自由基(OH.)和超氧阴离子自由基(O2-.)。     

海南黄芩中黄酮类化合物的分离与鉴定

目的:分离纯化海南黄芩中黄酮类化合物,并对其进行结构鉴定。方法:采用95%乙醇回流提取,醇提物用石油醚和氯仿萃取获得黄酮类化合物;采用岛津LC-10AD二元低压半制备液相色谱仪和Agilent半制备色谱柱(Phenyl,2.5 mm×25.0 cm,5μm)对氯仿萃取物进行分离纯化;采用高效液相色谱法对分离纯化获得的化合物进行纯度测定,并采用1H-NMR、13C-NMR波谱技术对其进行结构鉴定。结果:从海南黄芩中分离得到了5种化合物,纯度均大于95%,分别鉴定为5-羟基-7,8,2',6'-四甲氧基二氢黄酮、5,6,7-三羟基-2'-甲氧基黄酮、5,2'-二羟基-6,7-二甲氧基黄酮、黄芩素和黄芩素-7甲醚。结论:5种化合物均为首次从海南黄芩中分离得到,它们的获得丰富了海南黄芩化学成分组成,为其深入研究与开发提供了科学依据。     

麻栎叶黄酮的提取及其抗氧化活性研究

在单因素试验的基础上,对麻栎叶黄酮提取工艺进行优化,并研究了麻栎叶黄酮类化合物的抗氧化活性.结果显示,麻栎叶黄酮提取的最佳工艺是以60％乙醇为提取剂,提取物固液比1∶20,提取温度60℃,提取次数2次,微波功率640W、微波时间2 min,提取时间60 min,黄酮提取率为6.06 mg/g,回收率为96.5％.麻栎叶黄酮类化合物对自由基DPPH·、·OH以及亚硝酸盐的清除率分别达到97.7％、97.6％和94.4％.试验结果表明提取工艺合理,黄酮提取率高,麻栎叶黄酮提取液具有很好的抗氧化活性.     

黄芫花有效成分的研究

从黄芫花叶中所含黄酮类化合物中分离得5、7-二羟基,3'-甲氧基黄酮,4'-O-D 葡萄糖甙、5、7、4'-三羟基黄酮,3'-O-β-D 葡萄糖甙、5,7、3'、4'-四羟基黄酮,3-O-β-D 葡萄糖甙、5、7、3'、4'-四羟基黄酮-8-C-β-D 葡萄糖甙等四种黄酮甙;在醚溶性成分中分离得正三十一烷、三十烷醇、二十八烷醇及29-羟基二十九烷酮-3等四种成分。     

逆阿落中的黄酮化合物

从藏药逆阿落(Polygonum periginatoris Pauls)的乙酸乙酯提取物中分离得到四个黄酮化合物,通过波谱分析及化学方法鉴定了它们的结构,其中5,4’-二甲氧基．6,7-二氧亚甲基黄酮-3-0-β-芹糖(1→6)-β-葡萄糖甙(Periginatorine I)为新化合物,其余三个已知黄酮类化合物为首次从该植物中分离得到。     

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.