小果博落回中2种杀虫活性成分的分离及鉴定

以粘虫(Mythimna separata)3龄幼虫为试虫,采用生物活性示踪法从小果博落回(Macleaya microcarpa)乙醇提取物中分离纯化出2种活性成分,经MS1、H-NMR1、3C-NMR分析鉴定为二氢血根碱和二氢白屈菜红碱。采用小叶碟添加法测试了2种化合物对粘虫3龄幼虫的拒食及毒杀活性。结果表明,2种化合物对粘虫3龄幼虫均具有较高的拒食活性,48 h的拒食AFC50分别为0.168和0.231 mg.mL-1,同时,二氢血根碱对粘虫3龄幼虫具有一定的毒杀活性,96 h的LC50为0.085 mg.mL-1。分析认为二氢血根碱可能是小果博落回的主要杀虫活性成分之一。     

植物精油对几种害虫的毒杀活性

对 11科 15属 2 7种植物精油的杀虫活性做了测定。八角茴香果实、柠檬果实、细叶桉叶和留兰香叶精油对粘虫、小菜蛾、棉铃虫和玉米象有较强的熏蒸活性 ;精油稀释 10 0倍后 ,甜橙果实、玳玳花和砂地柏精油对粘虫的拒食活性最高 ;在 0 4% (w/w)剂量下 ,肉桂皮和八角茴香果实等 7种精油对玉米象的种群形成抑制率达 10 0 %。     

五种柏科植物挥发油成分的GC-MS分析

柏科植物是园林绿化中常用的常绿树种,具有种数多、分布广的特点。该研究采用水蒸气蒸馏法提取5种柏科植物叶片中的挥发油,利用气相色谱-质谱(GC-MS)与计算机检索联用技术对其化学成分进行分析和鉴定,并用面积归一法测定各组分的相对含量。结果表明:用水蒸气蒸馏法提取柏科植物挥发油得油率较高,除偃柏外4种柏树的得油率都在0.5%以上;5种柏科植物挥发油中共检测出了80种萜类物质,其中日本花柏中萜类物质最多含有54种,日本扁柏次之含有51种,柏木含有47种,线柏含有42种,偃柏则只含有35种;挥发油中含量较高的成分有乙酸龙脑酯、α-蒎烯、3-蒈烯、D-柠檬烯、松油烯-4-醇、桧烯和萜品油烯等,一些植物还含有龙脑、β-月桂烯、石竹烯、β-紫罗兰酮和Verticiol等一些重要的药用成分;柏科植物挥发油具有成分及相对含量差异大、成分较简单、化合物种类以萜烯类为主的特点。研究结果可为进一步开发利用柏科植物资源提供理论依据。     

小桐子果壳杀虫活性部位的分离及其HPLC MS分析

为寻找小桐子果壳的杀虫活性物质,以小桐子果壳乙醇粗提物的正丁醇萃取相为实验材料,对其采用硅胶柱反复柱层析,同时对各阶段分离产物进行活性追踪,筛选出具有杀虫作用的活性部位WD1,最后采用HPLC MS分析,初步鉴定出活性部位主体成分。结果表明,WD1活性组分在浓度为8 g?L 1时,对桃蚜(Myzus persicae）和菜青虫（Pieris rapae）的24 h（72 h）校正死亡率均大于70%,显示出极高的毒杀活性。通过对WD1进行HPLC MS分析,鉴定了含量较高的7个化合物,为总量的80.72%,初步鉴定为2a,3a,24 三羟基 12 20(30) 〖JP2〗二烯 28 乌索酸、环辛肽B、牡荆素、松香烷二萜、麻疯树酚酮A、Curcusone A或Curcusone B。     

粉红单端孢Trichothecium roseum对雄甾-4-烯-3,17-二酮的生物转化

雄甾-4-烯-3,17-二酮（4AD）是甾体化合物合成过程中的关键中间体,其羟化产物通常具有良好的药理活性或作为工业生产甾体药物的重要中间体。利用粉红单端孢Trichothecium roseum对4AD进行生物转化,从其发酵提取物中共分离鉴定了3个4AD羟基化产物：6β-羟基-雄甾-4-烯-3,17-二酮（6β-OH-4AD,1）,14α-羟基-雄甾-4-烯-3,17-二酮（14α-OH-4AD,2）,6β,14α-双羟基-雄甾-4-烯-3,17-二酮（6β,14α-di-OH-4AD,3）,表明T. roseum对4AD的C-6β位和C-14α位具有较强的羟化能力,其中14α-OH-4AD(2)可作为合成强心甾类化合物毛地黄毒素的重要中间体,6β,14α-di-OH-4AD(3)可作为合成具有抗肿瘤活性的14α-羟基-雄甾-4-烯-3,6,17-三酮的重要中间体。提供了1株能够高效制备活性甾醇中间体14α-OH-4AD和6β,14α-di-OH-4AD的菌株,同时可为研究其他甾醇药物奠定基础。     

大花美人蕉根的化学成分研究

为了解大花美人蕉(Canna generalis)的化学成分,从其根的乙醇提取物中分离得到8个化合物。通过波谱数据分析,分别鉴定为去氢催吐萝芙木醇(1)、3,4-二羟基苯甲酸乙酯(2)、咖啡酸乙酯(3)、豆甾-4,22-二烯-3,6-二酮(4)、豆甾-4-烯-3,6-二酮(5)、豆甾烷-3,6-二酮(6)、β-谷甾醇(7)和豆甾醇(8)。上述化合物均为首次从该植物中分离得到。     

链霉属放线菌Streptomyces antibioticus H12-15发酵物的化学成分研究

对采集于近南海红树林底泥的抗生链霉菌H12-15发酵物中的次级代谢产物进行分离纯化,经多种柱色谱技术得到10个化合物,通过波谱学方法并结合文献数据比对,鉴定所分离得到的化合物分别为:放线菌素X2(1)、放线菌素D(2)、羊毛甾醇(3)、4,4-二甲基酵母甾醇(4)、麦角甾醇过氧化物(5)、24-甲基-5α-胆甾基-7,22-二烯-3β,6α-二醇(6)、麦角甾-3β,5α,9α-三羟基-7,22-二烯-6-酮(7)、麦角甾-3β,5α,9α,14α-四羟基-7,22-二烯-6-酮(8)、5α,6α-环氧麦角甾-8,14,22-三烯-3β,7α-二醇(9)、β-谷甾醇(10),化合物3~10均为首次从海洋来源链霉菌中分离得到。运用MTT法对这10个化合物进行体外抗肿瘤细胞活性的筛选,其中,化合物1和2具显著生长抑制活性,其IC50值均小于1.6μg/mL;化合物9表现出一定的细胞毒活性。     

Studies on the chemical constituents of Kalimeris indica(Ⅱ)

采用冷渗漉提取的方法提取马兰的化学成分.经硅胶柱色谱和Sephadex LH-20进行分离纯化,通过理化方法和波谱数据分析进行结构鉴定.从80%乙醇冷渗漉提取物的水不溶物中分离并鉴定了12个化合物,分别为正十六烷酸(1)、6-羟基-桉烷-4(14)-烯(2)、β-谷甾醇(3)、α-菠菜甾醇(4)、香草醛(5)、β-20(21),24-二烯-达玛烷-3-酮(6)、豆甾醇(7)、木栓酮(8)、羽扇豆酮(9)、α-香树脂醇(10)、表木栓醇(11)、神经酰胺(12).化合物2、6、9、12均为首次从该种植物中分得.     

马兰化学成分研究 （Ⅱ）

采用冷渗漉提取的方法提取马兰的化学成分。经硅胶柱色谱和Sephadex LH-20进行分离纯化,通过理化方法和波谱数据分析进行结构鉴定。从80%乙醇冷渗漉提取物的水不溶物中分离并鉴定了12个化合物,分别为正十六烷酸(1)、6-羟基-桉烷-4(14)-烯(2)、β-谷甾醇(3)、α-菠菜甾醇(4)、香草醛(5)、β-20(21),24-二烯-达玛烷-3-酮(6)、豆甾醇(7)、木栓酮(8)、羽扇豆酮(9)、α-香树脂醇(10)、表木栓醇(11)、神经酰胺(12)。化合物2、6、9、12均为首次从该种植物中分得。     

脱氧鬼臼毒素对粘虫几种代谢酶系的影响

脱氧鬼臼毒素是砂地柏Sabina vulgaris Ant.中的主要杀虫活性成分之一。为探讨其作用机理,以叶碟饲喂法处理粘虫Mythimna separata Walker 4龄幼虫,测定了饲喂处理12h、24 h、36 h、48 h和72 h后试虫的羧酸酯酶（CarE）、酸性磷酸酯酶(ACP)、碱性磷酸酯酶(AKP)、谷胱甘肽S-转移酶（GSTs）和多功能氧化酶(MFO)的活性。结果表明：脱氧鬼臼毒素对粘虫羧酸酯酶的活性无明显影响;对酸性磷酸酯酶具有明显的抑制作用,且随着处理时间的延长,抑制作用增强;对碱性磷酸酯酶的影响较为复杂,表现为先抑制,后有所恢复,再被抑制的变化过程;对谷胱甘肽S-转移酶处理12 h后活性变化不明显,24 h后被抑制,36 h后逐渐激活,与对照差异极显著;对细胞色素P450酶系的O-脱甲基酶活性具有明显的抑制作用。     

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.