入侵植物猫爪藤体外细胞毒活性成分的筛选分离

为了筛选分离入侵植物猫爪藤的细胞毒活性成分,采用MTT法以75%乙醇提取物的不同组分分别处理人肝癌细胞SMMC7721、Bel7402和正常肝细胞Chang Liver,对他们的体外增殖抑制率进行了研究。结果表明,总醇提物的氯仿组分对肝癌细胞表现出明显的体外增殖抑制作用,其次是石油醚组分。从氯仿萃取组分中分离出具有更强细胞毒活性的成分熊果酸。因此,入侵植物猫爪藤具有体外细胞毒活性,熊果酸是其体外细胞毒活性的主要成分之一。     

七种中草药提取物抗肿瘤活性部位的筛选研究初报

选取叶下珠、珠子草、千里光、鸦胆子、使君子、冬青和猫爪藤等7种中草药进行提取和初步分离,筛选出有抗肿瘤效果的活性部位,并对其进行初步分析。采用MTT法,以7种中草药醇提物的不同分离部位分别对人肝癌、胃癌、卵巢癌等肿瘤细胞株进行体外增殖抑制作用研究,并以人正常肝细胞株为模型对照跟踪筛选活性部位。结果表明,从7种中草药醇提物中,均获得对肿瘤细胞株具有体外增殖抑制作用的化学分离部位,其中叶下珠和珠子草的乙酸乙酯层和正丁醇层的活性最显著,千里光的乙酸乙酯层、鸦胆子的正丁醇层、使君子和冬青的氯仿层活性次之,猫爪藤氯仿层和冬青的乙酸乙酯层活性较差,其他部位无活性。     

国家Ⅰ级重点保护极危植物藤枣研究进展

国家Ⅰ级重点保护植物藤枣[Eleutharrhena macrocarpa(Diels)Forman]属防己科单种属植物,主要分布于云南南部地区。藤枣因其形态特征和分布式样在防己科植物中较为独特,具有重要的植物系统学和区系地理学研究价值。据相关文献记载,目前发现和记录的藤枣自然种群数量小于60株,种群处于极危状态,面临灭绝风险。国内外与藤枣相关的研究资料也相对匮乏。为及时拯救和关注这一濒危物种,该文在前贤研究的基础上,总结报道了藤枣的分类学简史、科学研究价值、自然种群数量、濒危状况、生物多样性保护地位、区系分布、模式标本认定等方面的最新研究进展,提出了近期的研究目标。期望能对藤枣的准确鉴定、精准调查和进一步深入研究提供基础信息和理论参考。     

金钟藤分类考证及补充描述

旋花科植物金钟藤在中国华南地区已蔓延暴发成为"森林杀手",已引起各界的高度关注。该文对金钟藤的系统归隶、基名与异名、模式标本、分类文献,以及相关种进行考证和分析,澄清了一些误解和标本鉴定的错误,论证了金钟藤变种黄毛金钟藤在中国仅产于广西,而云南产的黄毛金钟藤实为铜钟藤,并把Merremia biosiana var.sumatrana van Ooststr.作黄毛金钟藤的新异名处理。     

永瓣藤濒危因素探讨

水瓣藤（MonimopetalumchinenseRehd．）是卫矛科（Celastraceae）的一个单种属植物,被列为国家二级珍稀濒危保护树种。永瓣藤濒危的因素主要是：（1）种子萌发障碍;（2）传粉受精不良,胚珠通常败育,结实率偏低;（3）种子成熟后胚因休眠或失水而失活;（4）人类活动对自然生态环境的严重干扰和破坏。本文提出了消除威胁生物多样性的社会因素、加强亚热带阔叶林生态系统的保护、重视自然保护区以外的就地保护工作、深入研究迁地保护的有效方法等保护策略。     

省藤组织培养的植株再生

省藤通常指棕榈科白藤属(Calamus L.)植物,该植物茎的商品名字称藤条,具有广泛的用途,主要用于编织藤器、家具和各种用具及工艺品,它是热带地区的一种经济价值很高的植物。 省藤通常用种子繁殖,但种子数量很有限,且容易丧失发芽力。由于热带雨林的严重破坏,省藤的品种及数量越来越少,有被灭绝的危险。而且,省藤同一品种的植株之间     

南山藤属植物化学成分及生物活性研究进展

萝藦科南山藤属植物广泛分布于亚洲和非洲南部,全株药用,临床应用广泛。化学结构类型包括甾体、苯丙素、寡糖等,其中C21甾体类成分为该属植物中主要化学结构类型,并具有抗肿瘤、抗抑郁、抗炎及免疫调节等作用。本文对南山藤属植物化学成分及生物活性进行综述,以期为更好地开发和利用南山藤属植物资源提供参考。     

中国千金藤属植物化学分类概况

探讨了各结构类型的异喹啉类生物碱在千金藤属植物中的分布规律及千金藤属植物的亲缘关系,在较原始的类群中,生物碱的结构类型和数量均较少,而在较进化的类群中内,其结构类型得到较大的发展,化合物的数量也相对增多,显示异喹啉类生物碱的结构类型及数量与属内植物群的进化有一定的对应关系,一些结构类型特化的生物碱和在植物界中分布极为狭窄的化学成分对亚属下各植物组的划分起着重要作用。     

植物小开放阅读框编码肽的研究进展

小开放阅读框（small open reading frame,sORF）一般指基因组中能够编码长度在100个氨基酸左右或以内短肽的开放阅读框。它们广泛存在于植物基因组,却因编码短肽而常被基因组注释忽视。随着翻译组学和蛋白质组学测序技术的发展,具有翻译活性的sORF被证实广泛存在于植物基因组,且参与植物生长发育等重要过程的调控。该文归纳了近些年来植物领域sORF的一些研究进展,主要包括sORF的来源与分类、信息学预测方法和生物学功能等,并基于此对植物sORF未来的研究方向进行了展望。     

蒜香藤叶挥发油的化学成分

蒜香藤（Pseudocalymma alliaceum Sandw．）又名紫铃藤,为紫葳科（Bignoniaceae）常绿藤状灌木,原产于南美洲的圭亚那和巴西。蒜香藤花、叶在搓揉之后,有浓浓的大蒜香味,其叶深绿富有光泽,花形大而优美,中国许多地方已引种栽培,一般作为篱笆、围墙美化或凉亭、棚架装饰之用。蒜香藤具有浓郁的蒜香,甚至可作为蒜的替代物用于烹饪。但有关其叶挥发性成分研究尚未见报道。本文利用气相色谱-质谱联用技术（GC—MS）分析了西双版纳植物园引种栽培的蒜香藤叶挥发油的化学成分,以期为合理开发和利用蒜香藤植物资源提供科学依据。     

The leaf-tying moth Hypocosmia pyrochroma (Lep., Pyralidae), a host-specific biological control agent for cat's claw creeper Macfadyena unguis-cati (Bignoniaceae) in Australia

Abstract:  Cat's claw creeper, Macfadyena unguis-cati , a major environmental weed in coastal and sub-coastal areas of Queensland and New South Wales, Australia is a target for classical biological control. Host specificity of Hypocosmia pyrochroma Jones (Lep., Pyralidae), as a potential biological control agent was evaluated on the basis of no-choice and choice larval feeding and survival, and adult oviposition preference tests, involving 38 plant species in 10 families. In no-choice tests, larval feeding and development occurred only on cat's claw creeper. In choice tests, oviposition and larval development was evident only on cat's claw creeper. The results support the host-specificity tests conducted in South Africa, and suggest that H. pyrochroma is a highly specific biological control agent that does not pose any risk to non-target plants tested in Australia. This agent has been approved for field release by relevant regulatory authorities in Australia.     

Metabolic engineering of seeds can achieve levels of omega-7 fatty acids comparable with the highest levels found in natural plant sources

Plant oils containing ω-7 fatty acids (FAs; palmitoleic 16:1Δ(9) and cis-vaccenic 18:1Δ(11)) have potential as sustainable feedstocks for producing industrially important octene via metathesis chemistry. Engineering plants to produce seeds that accumulate high levels of any unusual FA has been an elusive goal. We achieved high levels of ω-7 FA accumulation by systematic metabolic engineering of Arabidopsis (Arabidopsis thaliana). A plastidial 16:0-ACP desaturase has been engineered to convert 16:0 to 16:1Δ(9) with specificity >100-fold than that of naturally occurring paralogs, such as that from cat's claw vine (Doxantha unguis-cati). Expressing this engineered enzyme (Com25) in seeds increased ω-7 FA accumulation from <2% to 14%. Reducing competition for 16:0-ACP by down-regulating the β-ketoacyl-ACP synthase II 16:0 elongase further increased accumulation of ω-7 FA to 56%. The level of 16:0 exiting the plastid without desaturation also increased to 21%. Coexpression of a pair of fungal 16:0 desaturases in the cytosol reduced the 16:0 level to 11% and increased ω-7 FA to as much as 71%, equivalent to levels found in Doxantha seeds.     

Mycobacterium fortuitum subspecies acetamidolyticum, a new subspecies of Mycobacterium fortuitum

Mycobacterium fortuitum subspecies acetamidolyticum is a new subspecies of M. fortuitum and has an intermediate growth rate. It is a nonphotochromogenic mycobacterium. It does not utilize glutamate but utilizes acetamide as a simultaneous nitrogen and carbon source. It is able to utilize acetate, malate, pyruvate, fumarate, glucose, fructose, and n-propanol as the sole sources of carbon in the presence of ammoniacal nitrogen, but does not utilize them in the presence of glutamate-nitrogen. It is easily differentiated from all rapidly growing mycobacteria by its inability to utilize glutamate as a simultaneous nitrogen and carbon source, and from all slowly growing mycobacteria by its capacity to utilize acetamide as a simultaneous nitrogen and carbon source. Its mycolic acid pattern is different from that of M. fortuitum. However, its deoxyribonucleic acid showed 94% relatedness with that of M. fortuitum. In view of the above findings, it has been designated as a new subspecies of M. fortuitum. The organism was isolated from sputum of a 56-year-old patient with lung disease and is considered to be a lung pathogen. The type strain is ATCC 35931 (NCH E11620).     

扁苞蕗蕨和长柄蕗蕨的细胞分类学研究

本文首次报道了四川产扁苞蕗蕨和长柄蕗蕨的染色体及孢子发生情况。它们的染色体数目分别为 n=26和n=28,都是有性生殖的二倍体。染色体基数26在蕗蕨属的发现进一步证明了它和膜蕨属、厚壁蕨属的密切亲缘关系。这两种蕗蕨的孢子囊通常形成128个孢子及少数256个孢子的情况被描述,它们应该被看成是有性生殖真蕨,尤其是在膜蕨科和薄囊真蕨中的其他较原始的类群中的正常的孢子发生路线。     

Purification and properties of pyruvate kinase from Thermoplasma acidophilum

Thermoplasma acidophilum is a thermoacidophilic archaebacterium occupying a paradoxical place in phylogenetic trees (phenotypically it is a thermoacidophile but phylogenetically it classifies with the methanogens). To better understand its phylogeny, the pyruvate kinase from this organism is being investigated as a molecular marker. The enzyme has been purified and has a native M(r) of 250,000. It consists of four, apparently identical subunits each of M(r) 60,000. No remarkable kinetic differences have been found between this thermophilic enzyme and its mesophilic counterparts other than its greater thermostability. Its amino acid composition has been determined and some partial sequencing has been done.     

Freshwater Pearl mussels of the genus Margaritifera (Mollusca: Bivalvia) described as M. elongata (Lamarck, 1819) and M. borealis (Westerlund, 1871) should be classified with M. margaritifera (Linnaeus, 1758)

The shells of Pearl mussels from the basins of the Solza, Keret’, and Umba rivers flowing into the White Sea have been measured to determine the ratio of shell convexity to its maximum height. This ratio is the main character that, according to Bogatov et al. (2003), allows one to distinguish between three species of the genus Margaritifera: M. margaritifera, M. elongata, and M. borealis. It has been found that the above ratio gradually increases as the shell grows. Therefore, this character is unsuitable for species diagnosis, the more so that no hiatus in it between the three forms of pearl mussels has been revealed in any of the samples studied. On this basis, it may be concluded that Northern Europe, including Russia, is inhabited by only one species of pearl mussels, M. margaritifera.