Cu2+对喜树愈伤细胞中喜树碱合成的影响

喜树碱是一种从木本植物喜树(Camptothecaacuminata)中分离得到的抗癌活性物质,通过细胞培养合成喜树碱是喜树碱生产的一条重要途径。研究Cu~(2 )对喜树愈伤细胞培养中喜树碱积累的影响,结果表明,在B5培养基中添加0.008mg/mLCuCl2时,对喜树愈伤细胞的生长没有明显影响,但是对喜树愈伤细胞合成喜树碱的促进作用最强,喜树碱含量比未诱导前增加了约30倍。Cu~(2 )阻止培养细胞后期过氧化物酶活力的下降,并抑制花青素的生成。与黑暗培养相比,光照条件下添加Cu~(2 )更利于喜树愈伤细胞诱导合成喜树碱。     

不同产地和生长季节喜树叶中喜树碱含量测定

喜树(Camptotheca acuminata)是我国特有抗癌植物。本文通过测定不同产地的喜树幼嫩叶和成熟叶中喜树碱含量表明,均以四川都江堰所产喜树叶中喜树碱含量最高。不同生长月份的喜树嫩叶中喜树碱含量成一条单峰曲线,以7月喜树嫩叶中喜树碱的含量最高。     

犬蝠对小果野芭蕉的取食及种子传播

2004年9月到12月,在西双版纳热带植物园沟谷雨林内,通过详细的野外观察和雾网实验以及种子的定时收集方法,对犬蝠(Cynopterussphinx)取食小果野芭蕉(Musaacuminata)的行为及规律进行了研究。发现在夜晚24:00以前,犬蝠取食小果野芭蕉有明显的2个活动高峰,分别发生在20:30和22:30左右,这一结果与雾网采样结果较为一致。在研究期间的雨季(9-10月)和干季(11-12月),犬蝠平均被捕获量为2.2±0.3只/d、1.4±0.3只/d,二者之间没有显著的差异;同时这两个季节收集的种子团数量分别为9.0±1.1个/d和7.2±1.4个/d,也没有显著差异。犬蝠对小果野芭蕉种子的传播受生境影响较为显著,各样地间种子传播的结果大不相同;地点和季节对犬蝠传播种子也不存在交互影响。犬蝠对小果野芭蕉种子的传播距离为50-200m,是小果野芭蕉有效的种子传播者     

Six New Pentacyclic Triterpenoids from the Fruit of Camptotheca acuminata

Six new pentacyclic triterpenoids were isolated from the fruit of Camptotheca acuminata. The chemical structures of the new compounds were elucidated by extensive spectroscopic analysis including HR‐ESI‐MS, IR, UV, 1D‐ and 2D‐NMR. Moreover, the antibacterial activities of compounds 1 , 2 , 4 , 5 , and 6 were evaluated against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Dickeya zeae. All these tested compounds showed moderate antibacterial activity against Bacillus subtilis and Dickeya zeae.     

喜树的分泌结构及其与喜树碱积累的关系(英文)

为了揭示喜树碱(camptothecin,CPT)在喜树(Camptotheca acuminata Decne.)中的积累部位及积累规律,运用组织化学技术和高效液相色谱技术对喜树茎、叶中喜树碱的积累部位和含量进行了相关性分析。结果发现两类分泌结构与喜树碱积累密切相关:一类是分布于幼茎和幼叶表面的单细胞腺毛;另一类是分布于喜树幼茎和幼叶中的由1～2层细胞包围而成的分泌道。由此推断,喜树中的分泌结构为喜树碱的主要积累部位。     

Plant regeneration via somatic embryogenesis of <Emphasis Type="Italic">Camptotheca acuminata</Emphasis> in temporary immersion system (TIS)

The present study describes a protocol for plant regeneration via somatic embryogenesis in temporary immersion system (TIS) for Camptotheca acuminata. Somatic embryos were induced by culturing hypocotyl segments from 14-day-old in vitro grown C. acuminata seedlings in TIS. Hypocotyl segments were placed in culture vessels modified with a mechanical device to support the fixation of explants. Cultures were maintained under a 16 h photoperiod with a light intensity of 60 μmol m⁻² s⁻¹ PPF at 25 ± 1°C. After 16 weeks of incubation embryogenic calli were formed above the edge of the mechanical device in the basal Murashige and Skoog (MS) medium containing 35 g l⁻¹ sucrose and without hormonal supplementation. For plantlet regeneration, somatic embryos at cotyledonary stage were cultured in three different concentrations of 6-benzylamino-purine (0.5, 1.0 and 1.5 mg l⁻¹ BAP) and in plant growth regulator (PGR) free medium. In general, 0.5 mg l⁻¹ BAP was found to be the most effective concentration for growth and development of Camptotheca embryos in TIS. Conversion of somatic embryos into plantlets was also successfully achieved on sterile substrates moistened with 0.5 mg l⁻¹ BAP. Plantlets derived from cotyledonary embryos were rooted in vitro with 0.5 mg l⁻¹ indole-3-butyric acid (IBA) before transfer to ex vitro conditions.     

喜树果中喜树碱和10-羟基喜树碱的匀浆提取工艺

以喜树果为原料,对匀浆法提取喜树碱和10-羟基喜树碱的工艺进行了研究,确定了最佳的工艺条件：提取溶剂为体积分数55％的乙醇,匀浆时间为8min,料液比为1：15（g／mL）。在此工艺条件下,喜树碱和10-羟基喜树碱的提取率分别为0．801‰和0．546‰。将该法与超声提取、回流提取、常温冷浸提取、水浴振荡提取进行了比较,结果表明,匀浆提取具有得率高、省时间等方面的优势,是一种高效提取喜树碱和10．羟基喜树碱的方法。     

Characteristics of the microbial community in rhizosphere of Camptotheca acuminata cultured with exotic invasive plant Eupatorium adenophorum

The traditional culture-dependent plate counting and culture-independent small-subunit-ribosomal RNA gene-targeted molecular techniques, Single-Strand Conformation Polymorphism (SSCP) and terminal Restriction Fragment Length Polymorphism (tRFLP) combined with 16S rDNA clone library were adopted to investigate the impacts of secretion from Camptotheca acuminata (abbreviated to Ca) roots on the quantities and structure of eukaryotic microbes and bacteria in the rhizosphere, and the possibility that Ca controls exotic invasive plant Eupatorium adenophorum (Ea). The counting results indicated that the number of bacteria increased in turn in rhizospheres of Ea, Ca-Ea mixed culture and Ca, while that of eukaryotic microbes decreased. PCR-SSCP profiles showed eukaryotic microbial bands (corresponding to biodiversity) in rhizosphere of Ea were more complex than those of Ca and CE. Meristolohmannia sp., Termitomyces sp. and Rhodophyllus sp. were the dominant populations in the rhizosphere of Ca. Bacterial terminal restriction fragments (TRFs) profiles showed no difference among three kinds of rhizospheres, and the sequences of the 16S rDNA clone library from Ca rhizospheres were distributed in 10 known phyla, in which phylum Proteobacteria were the absolute dominant group and accounted for 24.71% of the cloned sequences (δ-Proteobacteria accounted for up to 17.65%), and phyla Acidobacteria and Bacteroidetes accounted for 16.47% and 10.59% of the cloned sequences, respectively. In addition, high performance liquid chromatography detected a trace amount of camptothecin and hydroxycamptothecin in the rhizospheric soil of Ca and CE, but examined neither camptothecin nor hydroxycamptothecin in rhizospheric soil of Ea. Therefore, invasion and diffusion of Ea evidently depended on distinguishing the eukaryotic community structure, but not on that of the bacterial pattern. Ca was able to alter the eukaryotic community structure of invasive Ea by secreting camptothecin and hydroxycamptothecin into rhizospheres, and may benefit the control of overspread of Ea. This study provided theoretical evidence for rhizospheric microbial aspects on substituting Ca for Ea. Supported by the Excellent Young Teacher’s Innovation Foundation of Northeast Forestry University to Yang FengJian, the Key Research Fund of Ministry of Education of China (Grant No. 104191) and the Forestry Noxious Plant Investigation Fund of State Forestry Administration of China to Zu YuanGang