南海软海绵Halichondria sp.化学成分研究

为了寻找有生物活性的次生代谢产物,对从采集自中国南海的软海绵(Halichondria sp.)进行了化学成分研究,从中共分离得到了9个化合物,并对部分化合物进行了抗菌活性测试。根据现代波谱技术并结合文献数据,鉴定化合物的结构为:1,2,3,4-四氢-3-羧基-2-卡波林(1),色氨酸(2),环(异亮氨酸-脯氨酸)(3),开环(脯氨酸-缬氨酸)(4),环(丙氨酸-脯氨酸)(5),胆甾醇(6),二-(2-乙基己基)邻苯二甲酸酯(7),邻苯二甲酸正丁异丁酯(8)和邻苯二甲酸二异丁酯(9)。     

毛果巴豆根的化学成分研究

对大戟科巴豆属植物毛果巴豆的根进行化学成分研究,并利用多种色谱方法分离得到11个化合物,根据理化性质和波谱学手段鉴定了结构。它们分别是3-乙酰高根二醇(1),3-乙酰齐墩果酸(2),ilexgenin A (3),(24S)-24-ethylcholesta-3β,5α,6β-triol(4),邻苯二甲酸二丁酯(5),邻苯二甲酸二异丁酯(6),邻苯二甲酸正丁异丁酯(7),Aralia cerebroside(8),熊果酸(9),β-谷甾醇(10),胡萝卜苷(11)。所有化合物均为首次从该植物中分离得到。     

海莲内生真菌Pestalotiopsis clavispora代谢产物研究

从海莲内生真菌Pestalotiopsis clavispora发酵液乙酸乙酯萃取物中分离得到9个化合物。根据波谱数据,化合物1－9结构分别鉴定为：3β,22β,24-三羟基齐墩果-12-烯,乌苏酸,3-羟基-4-甲氧基苯乙烯,邻苯二甲酸二异丁酯,3,4-二羟基苯乙醇,对羟基苯乙醇,3β-羟基-5α,8α-过氧化麦角甾-6,22-二烯,麦角甾-4,6,8(14),22-四烯-3-酮,胸苷。9个化合物均为首次从该内生真菌中分离得到。     

阳春砂仁的化学成分研究

从阳春砂仁Amomum villosum Lour.中分离得到14个化合物,经理化常数和波谱分析鉴定其结构分别为槲皮素(1)、槲皮苷(2)、异槲皮苷(3)、香草酸(4)、3,4-二羟基苯甲酸(5)、β-谷甾醇(6)、胡萝卜苷(7)、豆甾醇(8)、麦角甾醇(9)、麦角甾-7,22-二烯-3β,5α,6β-三醇(10)、硬脂酸(11)、棕榈酸(12)、白附子脑苷B(13)和虎杖苷(14)。其中,化合物1、9、10、13和14为首次从该种植物中分离得到。     

虎皮小牛肝菌的化学成分研究

采用硅胶、RP-18、Sephadex LH-20等多种材料进行分离纯化,通过理化方法和波谱分析进行结构鉴定,从虎皮小牛肝菌(Boletinus pictus)子实体的氯仿/甲醇(1:1,v/v)提取部位中分离并鉴定了9个化合物,它们分别为:亚油酸甲酯(1)、9(Z)-十八烷烯酸(2)、麦角甾-5,7,22-三烯-3β-醇(3)、麦角甾-4,6,8(14),22-四烯-3-酮(4)、麦角甾-7,22-二烯-3β,5α,6β,9α-四醇(5)、邻苯二甲酸二丁酯(6)、邻苯二甲酸二异丁酯(7)、烟酰胺(8)和尿嘧啶核苷(9).所有化合物均是首次从虎皮小牛肝菌中得到.     

紫苏内生真菌Aspergillus sp.12Y03化学成分研究

采用硅胶柱层析和Sephadex LH-20凝胶柱层析等分离方法,从紫苏内生真菌Aspergillus sp.12Y03发酵产物中分离鉴定了10个化合物,经现代光谱学技术鉴定为:环-(脯氨酸-甘氨酸)(1)、环-(脯氨酸-丝氨酸)(2)、环-(丝氨酸-4-OH-脯氨酸)(3)、环-(丙氨酸-4-OH-脯氨酸)(4)、环-(苯丙氨酸-甘氨酸)(5)、环-(丙氨酸-甘氨酸)(6)、亚油酸(7)、α-亚麻酸(8)、cerevisterol(9)和22E,24R-5α,6α-环氧麦角甾-8(14),22-二烯-3β,7α-二醇(10),均为首次从该菌种中分离得到,化合物3和4具有中等强度的海虾致死活性。     

南海软海绵Halichondria sp.化学成分研究

利用硅胶柱色谱、Sephadex LH-20、ODS柱色谱和HPLC等手段对南海软海绵Halichondria sp.化学成分进行分离纯化,从中分离得到了7个化合物。通过通过理化性质、波谱分析方法结合文献对照,鉴定了化合物的结构分别为:4α-Isocyanogorgon-11-Ene(1),homoverrucosanol(2),neoverrucosanol(3),5α,6α-环氧-(22E)-麦角甾-8,14,22-三烯-3β,7α-二醇(4),5α,8α-过氧-(22E,24R)-麦角甾-6,22-二烯-3β-醇(5),(22E,24R)-麦角甾-7,22-二烯-3β,5α,6α,9α-四醇(6),3β,5α,9α,14β-四羟基-(22E)-麦角甾-7,22-二烯-6-酮(7)。以上7个化合物都是首次从该属海绵中分离得到。对7个化合物进行了体外毒性实验,化合物1和3对HeLa肿瘤细胞株显示较弱的细胞毒性,其IC50值为33.7μM和43.8μM.     

极地真菌Geomyces sp.3-1次级代谢产物的研究

采用硅胶柱层析、ODS反相硅胶柱层析、凝胶柱层析和高效液相HPLC等色谱技术,对极地真菌Geomyces sp.3-1的发酵液提取物进行分离纯化,共得到8个化合物,通过波谱解析结合理化性质并比较相关文献,确定化合物为:paulownin(1)、demethylincisterol A3(2)、ergosta-7,22-dienen-3,6-dione(3)、citreoanthrasteroid B(4)、19-norergosta-5,7,9,22-tetraene-3β-ol(5)、(22E)-5α,8α-epidioxyergosta-6,22-dien-3β-ol(6)、(3β,5α,6β,22E)-6-methoxyergosta-7,22-diene-3,5-diol(7)和ergosta-7,22-dien-3β-ol(8)。其中,化合物2~7均是首次从Geomyces属真菌中获得,化合物2有较好的抗菌和细胞毒活性。     

缘毛紫菀化学成分研究

目的:对藏紫菀来源之一——缘毛紫菀(Aster souliei Franch.)的头状花序的化学成分进行研究。方法:采用硅胶柱层析、凝胶柱层析以及制备型液相等方法分离化学物,并采用光谱学方法进行结构鉴定。结果:从缘毛紫菀中分离鉴定了9个化合物,分别为黄酮类的槲皮素(1)、芹菜素(2)、山柰酚(3)、柚皮素(4)、芹菜素-7-O-β-D-吡喃葡萄糖苷(5)、芹菜素-7-O-β-D-吡喃葡萄糖醛酸苷(6);植物甾醇类的β-谷甾醇(7)、β-胡萝卜苷(8)、α-菠甾醇-3-O-β-D-吡喃葡萄糖苷(9)。结论:化合物4、9为该植物中首次分离得到。     

内生条纹拟盘多毛孢发酵液中细胞毒活性成分研究

从条纹拟盘多毛孢Pestalotopsis virgatula发酵液中分离得到8个化合物,其结构分别被鉴定为：2-(1-甲氧基-1-H-吲哚-3-基)乙醇 (1),2-(1-甲氧基-1-H-吲哚-3-基)乙酸 (2),3β-羟基-5α,8α-过氧化麦角甾-6,22-二烯 (3),麦角甾-4,6,8(14),22-四烯-3-酮 (4),对羟基苯乙醇 (5),邻苯二甲酸二异丁酯 (6),(E)-3-(4-羟基-3-甲氧苯基)败脂酸 (7) 和丁二酸 (8),化合物1–8均为首次从该菌种中分离得到。利用MTT法测试了化合物1 和2对5种人体肿瘤细胞的细胞毒活性,结果显示化合物1和2对5株肿瘤细胞株均具有一定选择性抑制活性。     

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.