天然产酮类化合物

)酮(Xanthone)又称苯骈色原酮,是一类黄色或无色的酚性化合物,具有与黄酮类(Flavonoids) 相似的颜色反应及色谱特性,因此曾被归入黄酮类讨论,但从其光谱特征看酮与黄酮是有区别的。 酮类在植物界的分布 酮类主要分布于龙胆科(Gentianaceae)、藤黄科(Guttiferae)、桑科(Moraceae)     

植物查尔酮异构酶研究进展

黄酮类化合物属于多酚类次生代谢物,具有广泛的药用价值。查尔酮异构酶（CHI）是黄酮类代谢途径中的一个关键酶,催化分子内环化反应,使双环的查尔酮转化为有生物学活性的三环（2S）-黄烷酮。植物体内的CHI活性与类黄酮物质的合成有着密切联系,CHI转基因研究对于提高植物类黄酮含量有重要意义。简要概述了查尔酮异构酶的结构特点、催化反应机理以及CHI转基因的研究进展。     

大叶藤黄叶片的化学成分及其抗氧化活性研究

为了解药用植物大叶藤黄(Garcinia xanthochymus)叶片的化学成分,采用UPLC-QTOF-MS从叶片中得到19个化合物,主要为双黄酮类、黄酮类和间苯三酚类化合物。采用色谱分离法从叶片的80%甲醇提取物中分离得到5个单体化合物,根据理化性质及波谱数据,分别鉴定为二氢山奈酚(1)、dulcisbiflavonoid A (2)、7-去甲基银杏双黄酮(3)、mono-[2-(4-carboxyphenoxycarbonyl)-vinyl]ester (4)、山奈酚(5)。化合物1和2为首次从大叶藤黄中分离得到,化合物3和4为首次从藤黄属植物中分离得到。化合物1和5清除DPPH自由基的IC50值分别为146.8和39.0μg/m L,表明其具有抗氧化活性。     

藤黄酸聚乳酸纳米粒的研制

以新型材料聚乳酸(PLA)为载体,研制出质量稳定的藤黄酸聚乳酸纳米粒(GA-PLA-NPs)乳液制剂,并对其安全性进行评价。采用改良的溶剂蒸发法制备藤黄酸聚乳酸纳米粒(GA-PLA-NPs);用透射电子显微镜（TEM）观察纳米粒的形态;用激光粒度分析仪测定其平均粒径大小和分布;经超速离心后用紫外分光光度计测定纳米粒的包封率与载药量;考察藤黄酸纳米粒的体外释放特性;经急性毒性实验考察藤黄酸纳米粒的安全性。得到确定处方工艺为：水相∶有机相为2∶1（v/v）,表面活性剂在有机相中的浓度为0.5%（w/v）,藤黄酸（GA）在有机相中的浓度为0.1%（w/v）,GA∶PLA为1∶4（w/w）。处方条件下制备的纳米粒平均粒径为51.36 nm;平均包封率与载药量分别为98.87%和13.3%;藤黄酸纳米粒的体外释药分为两相：突释期和缓释期;急性毒性试验测得藤黄酸纳米粒的ID50为26.3mg/kg。制备的藤黄酸聚乳酸纳米粒（GA-PLA-NPs）质量稳定、分散性良好。聚乳酸可能成为藤黄酸的新型载体。     

两种氮素形态对药用植物三叶青中黄酮类活性成分积累的影响及相关分子机制的初步探讨

以珍稀濒危药用植物三叶青（Tetrastigma hemsleyanum Diels et Gilg）为材料,通过遮荫条件下（30%自然光）的盆栽试验,研究了硝态氮（NO₃^--N）和铵态氮（NH₄⁺-N）两种不同氮素形态对其根和叶中黄酮类活性成分含量的影响并探讨其机制。结果表明：NO₃^--N处理后的三叶青叶中原花青素B1、芦丁、山柰酚-3-O-芸香糖苷、槲皮素、异槲皮苷、山柰酚的含量比NH₄⁺-N处理的高;其根中的原花青素B1、芦丁、山柰酚-3-O-芸香糖苷、槲皮素、异槲皮苷、山柰酚的含量比NH₄⁺-N处理的高。进一步的研究发现NO₃^--N处理过的三叶青其根、叶中与黄酮类化合物合成相关的酶苯丙氨酸解氨酶（PAL）、查尔酮合成酶（CHS）转录与表达水平高于NH₄⁺-N处理的三叶青。此外,NO₃^--N处理的三叶青叶、根中的PAL和CHS酶活性也高于NH₄⁺-N处理。利用PAL特异性抑制剂AOA处理后,AOA能显著抑制PAL酶活性（P<0.05）并导致黄酮类成分含量极显著下降（P<0.01）。综上所述,施用NO₃^--N更有益于三叶青黄酮类化合物的生物合成,其主要是通过增加PAL代谢途径关键酶的基因表达量进而提高其酶活性来增强黄酮类化合物的合成。     

金线莲里的活性成分

正金线莲为我国传统的名贵中草药,具有多种活性成分,素有"金草"之美誉。近年5来,"金线莲热"持续不下,价格也居高不下。那么,我们就金线莲活性成分来分析其为何如此"热"。黄酮类黄酮类化合物是一类具有2-苯基色原酮结构的化合物,广泛分布于自然界中,绝大多数植物体内都含有黄酮类化合物。在植物体中,黄酮类化合物常与糖结合成苷类,只有小部分以游离态(苷元)的形式存在。植物中的黄酮类化合物对于植物本身也具有重要的意义,在植物的生长、发育、开花、结果过程中均起着重要的作用,具有抗菌防病的功效。黄酮类化合物具有多种     

美洲曼密苹果树

美洲曼密苹果树汪开治曼密苹果又称黄果木（Ｍａｍｍｅａ）,隶属于藤黄科（即山竹子科）,该属共约４７种。我国有云南曼密苹果树１种,产于云南。美洲曼密苹果树（Ｍａｍｅｒｉｃａｎａ）为常绿乔木,产于西印度群岛和南美洲北部。热带美洲普遍栽培。花香。果实圆形,...     

湖北小连翘中化学成分的高效液相色谱与电喷雾离子化质谱联用分析

湖北小连翘(Hypericum hubeiense L.H.Wu et D.P.Yang)是2004年在我国发现的一个金丝桃属(Hypericum)植物(藤黄科)新种.利用高效液相色谱与质谱联用技术对该植物中主要化学成分进行了分离分析,初步鉴定出金丝桃素类、黄酮类等12种化学成分.同时,以金丝桃素为外标,采用HPLC法在590 nm波长下测定了金丝桃素类成分的含量.     

樱草杜鹃中的黄酮类化合物

从樱草杜鹃（Rhododendron primulaeflorum）地上部分的乙醇提取物中分离得到10个黄酮类化合物,经理化性质及波谱分析,鉴定为杜鹃素（1）、4’,5,7-三羟基-8-甲基黄烷酮（2）、二氢山柰酚（3）、异鼠李素（4）、槲皮素（5）、陆地棉苷（6）、瑞诺苷（7）、（2R,3R）－花旗松素-3—O-α-L-吡喃阿拉伯糖苷（8）、（2R,3S）-花旗松素-3—O-α-L-吡喃阿拉伯糖苷（9）、（2S,3R）－花旗松素－3－O－α－L－吡喃阿拉伯糖苷（10）。所有化合物均为首次从该植物中分得。     

红厚壳挥发油化学成分

红厚壳（Calophyllum inophyllum Linn．）,又名海棠果、胡桐等,为藤黄科（Guttiferae）红厚壳属（Calophyllum Linn．）植物,主要分布于中国海南岛。其果实和种子富含油脂,可制香料;植株根系发达,耐盐碱、抗风性强,可以在贫瘠干旱的海滨、山地中生长,具有良好的开发应用前景。在中国民间,红厚壳被用作治疗眼病、外伤出血、风湿骨痛、跌打损伤等。红厚壳属于半红树植物,可生长于海岸潮间带,     

十七种虫草的子实体培育研究

在过去的12年间,分离得到20余种虫草无性型,对其中十七种虫草无性型进行了人工诱发虫草子座的试验,结果表明:蜂头虫草Cordycepssphecocephala、亚黄蜂虫草C.oxycephala、蚂蚁草C.myrmecophila、蛹虫草C.militaris、拟细虫草C.gracilioides和布氏虫草C.brongniatii等6种人工培养的虫草观察到了成熟的子囊壳并弹射了子囊孢子;古尼虫草小孢变种C.gunniivar.minor、球孢虫草C.bassiana、戴氏虫草C.taii、蚁虫草C.formicarum、蝽虫草C.nutans、长座虫草C.longissima、台湾虫草C.formosana和双梭孢虫草近似种C.bifusisporaaff.长出了许多的未成熟的子座或孢梗束;而冬虫夏草C.sinensis、沫蝉虫草C.tricentri和细虫草C.gracilis未能培育出子实体。其中蚁虫草和亚黄蜂虫草的人工成功培育子实体为首次报道。     

中国靴耳属分类研究概况

对已报道的我国Crepidotus属种类进行了全面汇总,并概述了其分类研究现状。文献调查结果表明:国内已报道的该属种类名称共31个,包括30个种和1个变种,分布于全国26个省区。已报道的全部记录中,28个分类单元引证了标本,其余3个记录缺乏标本引证;7个记录的描述与国外权威描述存在差异,另有4个记录的报道未提供形态描述。淡紫靴耳不是Crepidotus属的成员,已被组合到其他属中。笔者接受"靴耳属"为Crepidotus属的汉语学名,并以此为属主名对属下的分类单元进行了全面修订。     

六种苏铁属植物的羽片比较解剖学研究

研究了锈毛苏铁（Cycas ferruginea),石山苏铁（C.miquelii),四川苏铁（C.szchuanensis),海南苏铁（C.hainanensis),仙湖苏铁（C.fairylakea)和贵州苏铁（C.guizhouensis)等六种苏铁属植物羽片的比较解剖学,结果显示锈毛苏铁与石山苏铁在下皮层厚壁细胞,海绵组织中含晶细胞,中脉隆起,叶缘形态,韧皮部形态及分泌道的有无等特征上具有较明显的差异,四川苏铁与海南苏铁和仙湖苏铁非常相近;海南苏铁与仙湖苏铁基本一致;贵州苏铁在中脉隆起,叶缘形态,韧皮部形态等方面与四川苏铁,海南苏铁及仙湖苏铁三者有差异。支持将锈毛苏铁,石山苏铁独立为种的观点,并认为海南苏铁与仙湖苏铁不能区分,四川苏铁与海南苏铁和仙湖苏铁具有较近的种系关系,贵州苏铁与其它种的种系关系相对较远。     

The surface wax composition of the exuviae and adults of Aleyrodes singularis

Long-chain aldehydes, alcohols, hydrocarbons and wax esters were major components of the external lipids of adult Aleyrodes singularis. In exuviae, acetate esters replaced the hydrocarbons as a major component. The major long-chain alcohol and aldehyde from adults were C32 and were essentially the exclusive components of the wax particles. The major alcohol from exuviae was C26 and the aldehydes were C26, C28, C30 and C32. The major acetate esters were C28 and C30 in both adults and exuviae. There were wax esters of similar carbon number in adults and exuviae although the exuviae had a greater amount of wax esters with unsaturated fatty acids. The fatty acid and alcohol composition of the wax esters differed markedly between adults and exuviae. Wax esters of adults had similar amounts of C16, C18, C20, C22 and C24 fatty acids while those from exuviae contained largely C16 and C18. The major alcohol in the wax esters of adults was C22 and those of exuviae were C26 and C28. The distribution of fatty acids and alcohols among wax esters of varying chain length also differed between adults and exuviae: in adults C22 was the major fatty acid found in the dominant wax ester, C44 and the C22 alcohol was the major alcohol and found in wax esters C42 and C44. In exuviae C16 and C18 were the major fatty acids found in most wax esters and a C28 alcohol was the major alcohol found in wax esters C44 and C46, the two dominant wax esters in exuviae. It was clear that the difference in chemistry of the wax esters between the adults and exuviae is not evident unless the acid and alcohol moieties are characterized.     

六种苏铁属植物的羽片比较解剖学研究

研究了锈毛苏铁（Cycas ferruginea）、石山苏铁（C. miquelii）、四川苏铁（C. szechuanensis）、海南苏铁（C. hainanensis）、仙湖苏铁（C. fairylakea）和贵州苏铁（C. guizhouensis）等六种苏铁属植物羽片的比较解剖学,结果显示锈毛苏铁与石山苏铁在下皮层厚壁细胞、海绵组织中含晶细胞、中脉隆起、叶缘形态、韧皮部形态及分泌道的有无等特征上具有较明显的差异;四川苏铁与海南苏铁和仙湖苏铁非常相近;海南苏铁与仙湖苏铁基本一致;贵州苏铁在中脉隆起、叶缘形态、韧皮部形态等方面与四川苏铁、海南苏铁及仙湖苏铁三者有差异。支持将锈毛苏铁、石山苏铁独立为种的观点,并认为海 南苏铁与仙湖苏铁不能区分。四川苏铁与海南苏铁和仙湖苏铁具有较近的种系关系,贵州苏 铁与其它种的种系关系相对较远。     

中国毛壳菌科研究Ⅰ. ——毛壳菌属的种

报道了毛壳菌属的十一个种,旋丝毛壳 Chaetomium bostrychodes,反卷毛壳 C. convolutum,舟形毛壳 C. cymbiforme,高大毛壳 C. elatum,粪生毛壳 C. funicola,球孢毛壳 C. globosporum,球毛壳 C. globosum,细丽毛壳 C. gracile,六孢毛壳 C. hexagonosporum,印度毛壳 C. indicum和近缘毛壳C. subaffine。其中包括四个中国新记录种:舟形毛壳 C. cymbiforme,球孢毛壳 C. globosporum,六孢毛壳 C. hexagonosporum和近缘毛壳 C. subaffine。根据我国的标本和菌种对新记录种作了描述,并附了显微照片。标本与菌种保存在西北农林科技大学真菌标本室 (HMUABO)。     

A phylogenetic study on galactose-containing Candida species based on 18S ribosomal DNA sequences

Phylogenetic relationships of 33 Candida species containing galactose in the cells were investigated by using 18S ribosomal DNA sequence analysis. Galactose-containing Candida species and galactose-containing species from nine ascomycetous genera were a heterogeneous assemblage. They were divided into three clusters (II, III, and IV) which were phylogenetically distant from cluster I, comprising 9 galactose-lacking Candida species, C. glabrata, C. holmii, C. krusei, C. tropicalis (the type species of Candida), C. albicans, C. viswanathii, C. maltosa, C. parapsilosis, C. guilliermondii, and C. lusitaniae, and 17 related ascomycetous yeasts. These three clusters were also phylogenetically distant from Schizosaccharomyces pombe, which contains galactomannan in its cell wall. Cluster II comprised C. magnoliae, C. vaccinii, C. apis, C. gropengiesseri, C. etchellsii, C. floricola, C. lactiscondensi, Wickerhamiella domercqiae, C. versatilis, C. azyma, C. vanderwaltii, C. pararugosa, C. sorbophila, C. spandovensis, C. galacta, C. ingens, C. incommunis, Yarrowia lipolytica, Galactomyces geotrichum, and Dipodascus albidus. Cluster III comprised C. tepae, C. antillancae and its synonym C. bondarzewiae, C. ancudensis, C. petrohuensis, C. santjacobensis, C. ciferrii (anamorph of Stephanoascus ciferrii), Arxula terrestris, C. castrensis, C. valdiviana, C. paludigena, C. blankii, C. salmanticensis, C. auringiensis, C. bertae, and its synonym C. bertae var. chiloensis, C. edax (anamorph of Stephanoascus smithiae), Arxula adeninivorans, and C. steatolytica (synonym of Zygoascus hellenicus). Cluster IV comprised C. cantarellii, C. vinaria, Dipodascopsis uninucleata, and Lipomyces lipofer. Two galactose-lacking and Q-8-forming species, C. stellata and Pichia pastoris, and 5 galactose-lacking and Q-9-forming species, C. apicola, C. bombi, C. bombicola, C. geochares, and C. insectalens, were included in Cluster II. Two galactose-lacking and Q-9-forming species, C. drimydis and C. chiropterorum, were included in Cluster III.     

Phosphatidylcholine bilayers: subtransitions in pure and in mixed lipids

Aqueous dispersions of C14, C16, C17 and C18 phosphatidylcholines (PC, where Cn denotes di-acyl of n carbons per chain), and mixtures of C14/C16PC and C16/C17PC were prepared and their thermal properties studied by differential scanning calorimetry (d.s.c.) after sample storage at 2-6 degrees C for up to 22 days. C16PC and C18PC display subtransitions at 22 degrees C and 29 degrees C, respectively, as previously reported by Chen et al. (Proc. Natl. Acad. Sci. U.S.A. 77 (1980) 5060-5063). C17PC shows two subtransitions at 21 degrees C and 26 degrees C, respectively, which are independent of each other. Although C16PC and C17PC individually develop subtransitions, an equimolar mixture does not. However, mixtures of C14/C16PC containing 10 or more mol% of C14PC do display a subtransition. These results underscore the primary dependence of subtransition formation in phosphatidylcholine dispersions on acyl chain structure.     

Analysis of human C8 with monoclonal antibodies. Characterization of a monoclonal antibody that recognizes free C8 alpha-gamma subunit

The eighth component of human C is essential for the formation of the membranolytic C attack complex. C8 has a unique structure in that two covalently linked chains, C8 alpha and C8 gamma, are associated non-covalently with the third chain, C8 beta. In order to study the structure and assembly of the C8 molecule, a panel of mAb has been produced against the C component C8. Eight of these mAb had reactivity to the C8 alpha-gamma subunit, whereas four reacted with C8 beta. One of the C8 alpha-gamma mAb, C8A2, had specificity for an epitope on the C8 alpha-chain and exhibited no cross-reactivity to any of the other terminal C components, including C8 beta. C8A2 inhibited the hemolytic activity of the C8 alpha-gamma subunit but had no effect on the activity of fluid phase whole C8 or C8 within membrane-bound C5b-8. Functional experiments suggest that C8A2 inhibits C8 alpha-gamma activity by interfering with its interaction with the C8 beta-chain. In an enzyme immunoassay using the C8A2 mAb, free C8 alpha-gamma subunit could be detected in both homozygous and heterozygous C8 beta-deficient serum. However, only low level binding was observed when homozygous C5- and C7-deficient sera were tested. Thus the mAb, C8A2, recognizes an epitope expressed on the C8 alpha-gamma subunit but not on intact C8 and can detect free C8 alpha-gamma in the presence of native C8.