内生芬芳镰刀菌Dzf2中两个抗菌活性成分(英文)

采用活性追踪的方法从盾叶薯蓣内生芬芳镰刀菌Dzf2中分离到两个抗菌活性成分,通过物理化学性质和波谱学特征鉴定为镰刀菌酸(1)和9,10-脱氢镰刀菌酸(2)。采用多孔板-MTT-比色法和孢子萌发法测定了化合物的抗菌活性。镰刀菌酸和9,10-脱氢镰刀菌酸对供试细菌的半抑制浓度(IC50)值为35.35μg/mL至171.29μg/mL;对稻瘟菌孢子萌发的IC50值分别为28.83μg/mL和27.06μg/mL。     

水葫芦内生拟枝孢镰刀菌SC1608的次生代谢产物

研究了一株水生植物水葫芦内生拟枝孢镰刀菌Fusarium sporotrichioides SC1608大米发酵物的抗真菌活性次生代谢产物,从中共分离获得6个化合物,经高分辨质谱、三重四极杆质谱和核磁共振谱分析,分别鉴定为4个鞘糖脂类化合物:asperamide B(1)、asperamide D(2)、asperam...     

紫珠的松香烷型二萜成分研究

从紫殊全草的乙醇提取物的氯仿部分中分得5个松香烷型二萜,经光谱数据分别鉴定为脱氢枞酸(1)、7β-羟基-脱氢枞酸(2)、7α-羟基-脱氢枞酸(3)、7-羰基-脱氢枞酸(4)和18-羧基-6,8,11,13-松香烷酸。以上化台物均为首次从该植物中分得。     

毛咀地星的抗氧化、抗菌和抗肿瘤活性和化学成分研究

毛咀地星是一种药用蘑菇,为了进一步开发利用毛咀地星,该研究探讨了毛咀地星乙醇提取物的抗氧化、抗菌和抗肿瘤活性,并采用硅胶柱色谱、制备薄层色谱和重结晶等方法,对毛咀地星乙醇提取物进行分离纯化,研究了其化学成分。结果表明:毛咀地星乙醇提取物多酚含量为10.53μg·mg~(-1),DPPH和·OH自由基清除能力的IC50值分别为91.35和148.76μg·m L~(-1);乙醇提取物对金黄葡萄球菌、大肠杆菌和枯草芽抱杆菌均无抑制作用;乙醇提取物在浓度为1 mg·m L~(-1)时,对燕麦镰刀菌的抑制率为36.11%;乙醇提取物在浓度为200μg·m L~(-1)时,对BG-803、NCI-H502和MDA-MB-231肿瘤细胞的抑制率分别为18.87%、17.71%和41.23%。并从乙醇提取物中分离纯化到6个化合物,根据理化性质和波谱数据分析,化合物结构分别鉴定为5α,8α-过氧化麦角甾-6,9(11),22-三烯-3β-醇(1)、5α,8α-过氧化麦角甾-6,22-二烯-3β-醇(2)、D-阿拉伯糖醇(3)、L-谷氨酸(4)、麦芽糖(5)和蔗糖(6),以上化合物均为首次从该菌中分离得到。     

盐地碱蓬内生菌Neocamarosporium sp. ZLM-26次级代谢产物

本研究对盐地碱蓬内生菌Neocamarosporium sp. ZLM-26的活性次级代谢产物进行了挖掘。采用薄层色谱、硅胶柱色谱、高效液相色谱等分离方法,从该菌株大米培养基发酵产物的乙酸乙酯萃取物中分离得到6个单体化合物,经波谱学解析和文献数据对比,鉴定6个化合物分别为：5-butyl-6-(hydroxymethyl)-2H-pyran-2-one(1)、(7S)-xylariolide E(2)、(6S)-xylariolide D(3)、diaporpyrone A(4)、4-hydroxybenzaldehyde(5)和2-(2-hydroxyethyl) phenol(6)。分别采用CCK-8法和96孔板法评估了6个化合物的抗肿瘤和抗菌活性。结果显示,6个化合物(50 μmol/L)对胰腺癌细胞株SW1990、PANC-1的增殖无明显抑制作用;而化合物4对大肠杆菌有较好的增殖抑制活性,化合物5、6对铜绿假单胞菌有较好的增殖抑制活性。化合物1为1个新的天然产物,本研究首次报道了其核磁数据和抗菌活性。此外,化合物1–4均为首次从新凸轮孢菌属真菌中分离得到。     

人面果抗氧化活性成分研究

采用DPPH法对人面果树皮和根部不同溶剂提取物进行抗氧化活性研究.结果表明人面果树皮乙酸乙酯提取物的抗氧化活性最强.运用正相和反相硅胶柱层析对人面果树皮乙酸乙酯提取物进行分离纯化,用波谱技术(1D和2D NMR)分析鉴定出2个xanthone类化合物:1,5-dihydroxy-3-methoxyxanthone(1)和2,5-di-hydroxy-1-methoxyxanthone(2),化合物1和2均为首次从该植物中发现.对化合物1和2进行抗氧化活性研究,结果表明化合物1和2显示了一定的抗氧化活性.     

樟子松针叶化学成分研究

该研究以采自黑龙江省齐齐哈尔市的樟子松(Pinus sylvestris)针叶为对象,采用溶剂提取法对樟子松针叶中的化学成分进行提取,应用硅胶柱色谱、制备薄层色谱和高效液相色谱等现代色谱技术对提取浸膏中的化学成分进行分离和纯化,运用质谱,核磁(1H-NMR和13C-NMR)等波谱技术,鉴定了化合物结构,并对提取浸膏的抑菌活性进行了测试。结果表明:从樟子松针叶提取物中分离得到15个化合物,分别鉴定为松叶酸(1)、松叶酸甲酯(2)、18α-acetoxylabd-8(17)-en-15-oic acid (3)、4-eplimbricataloic acid (4)、15-乙基-18-松叶酸甲酯(5)、15-acetoxy-labda-8(17),13E-dien-18-al (6)、7β-羟基脱氢枞酸(7)、7α-羟基脱氢枞酸(8)、endo-peroxide (9)、α-杜松醇(10)、β-谷甾醇(11)、邻苯二甲酸二丁酯(12)、7R,11R-phytol (13)、正二十四烷醇(14)、N-octacosan7β-ol (15)。其中,化合物9,13,14和15为首次从该属植物中分离得到。抑菌活性结果表明,正己烷萃取浸膏在浓度为5~100 mg·mL~(-1)时对大肠杆菌和枯草芽孢菌的抑菌率分别为53%~71%和56%~70%,在浓度为50 mg·mL~(-1)和100 mg·mL~(-1)时对金黄色葡萄球菌的抑菌率分别为51%和69%。该研究课题进一步明确了樟子松针叶中的化学成分,为其活性测试及应用研究提供依据。     

朴树内生镰刀菌HU0174抗真菌次生代谢产物研究

通过硅胶柱层析、大孔吸附树脂柱层析和高效液相制备等色谱技术从一株朴树内生镰刀菌Fusarium sp.HU0174的大米发酵物中分离得到一个新的环酯肽:acuminatum D(1)和6个已知化合物:acuminatums A～C(2～4)、白僵菌素(5)、白僵菌酮(6)和吲哚-3-羧酸(7),运用NMR和MS等谱学方法鉴定了它们的化学结构。采用滤纸片琼脂扩散法测试表明环酯肽类化合物1～4对柑橘绿霉和新月弯孢霉两株植物致病真菌具有明显的体外抑制活性,初步阐明了镰刀菌HU0174的抗真菌活性物质基础。     

一株茄病镰刀菌的代谢产物研究

一株茄病镰刀菌（Fusarium solani）固体发酵培养物经柱层析分离得到10个化合物。通过波谱分析,分别鉴定为对羟基苯甲酸甲酯（1）、水杨酸甲酯（2）、水杨酸戊酯（3）、香草乙酮（4）、草夹竹桃苷（5）、2-甲氧基-4-乙烯苯基-β-D-吡喃葡萄糖苷（6）、1-O-β-D-glucopyranosyl-(2S,3R,8E)-2-[(2R)-2-hydroxylpalmitoylamino]-8-octadecene-1,3-diol（7）、1-O-β-D-glucopyranosyl-(2S,3R,4E,8E)-2-[(2R)-2-hydroxyhexadecanoylaino]-8-octadecene -1,3-diol （8）、脑苷脂D（9）和脑苷脂C（10）。所有化合物均为首次从茄病镰刀菌中分离得到,其中化合物6首次作为天然产物报道。     

链霉菌KIB-H1556次级代谢产物抗植物真菌活性研究

对曼陀罗(Datura stramonium L.)根际链霉菌Streptomyces sp.KIB-H1556的次级代谢产物进行研究,利用硅胶柱色谱、凝胶柱色谱和半制备HPLC等分离手段对其发酵产物进行分离纯化,采用MS和NMR等波谱学手段并结合文献数据鉴定了3个单体化合物的结构,分别为:Bafilomycin D(1)、Bafilomycin B1(2)和Bafilomycin B2(3)。初步抗植物病原真菌活性筛选发现化合物2和3具有广谱抗真菌活性,尤其对玉米病原真菌的抑制活性显著,可作为玉米病原真菌病害的潜在生物防治剂。     

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.