You are what you eat: native versus exotic Crotalaria species (Fabaceae) as host plants of the Ornate Bella Moth,Utetheisa ornatrix (Lepidoptera: Erebidae: Arctiinae)

Crotalaria plants and Utetheisa ornatrix are closely linked to each other: the larvae destroy the seeds, while the moth depends on hostplants for alkaloids. To better understand the ongoing co-evolution, the present study examines how native hostplants compare to exotic ones. Leaf-feeding on Crotalaria pumila, C. rotundifolia, and C. incana, native to the moth’s range, led to faster larval development than on the exotic C. lanceolata, C. spectabilis, and C. pallida. Seed-feeding on all species of Crotalaria led to accelerated larval development and a resultant larger adult moth, and correlates with a higher nitrogen content in the plant tissues. These results add a novel dimension to the previous studies of reproductive biology of this model organism. In controlled settings, mature larvae showed preference for leaves of C. spectabilis over those of other species, perhaps due to the higher alkaloid content. Differences in morphology and phenology of Crotalaria determine the ecology of U. ornatrix populations in Florida. The introduction of novel hostplants, on which U. ornatrix can have a significant negative effect and which are of concern to humans as invasive toxic weeds, has greatly expanded the niche occupied by this moth. Possible co-evolution of Utetheisa sensu lato and plant defences in the genus Crotalaria is discussed.     

利用植物次生代谢产物开发生物农药

叙述了甘肃地区杀虫植物资源的初步调查结果及具有杀虫作用的植物次生代谢物质生物碱的研究情况,并就这一领域的研究状况作了概要介绍。     

二萜类生物碱的药理作用及构效关系研究概况

二萜类生物碱是一类生物活性较强的植物成分，具有多种药理作用，但其往往又表现出不同程度的毒性，它们的结构和活性之间有着密切的关系，总结了二萜类生物碱的药理作用，并概述了其构效关系。     

Role of the δ 8 double bond of agroclavine in lysergic acid amide biosynthesis byClaviceps purpurea

Summary Agroclavine, given to actively-growing sclerotial tissue of a strain ofClaviceps purpurea which can not normally elaborate ergot alkaloids, was transformed by this tissue into lysergic acid amide with overall efficiency of approximataly 40%. By contrast, festuclavine (8, 9-dihydro-agroclavine) was not transformed, indicating specificity in the mechanism of lysergyl biosynthesis.     

Implication of C-5, C-6 unsaturation as a key structural factor in steroidal alkaloid-induced mammalian teratogenesis

Hamster teratogenicity induced upon oral administration of steroidal alkaloids (solanidanes, spirosolanes and jervanes) appears to relate very closely to the presence or absence of C-5, C-6 unsaturation in the alkaloid, which may be more important than molecular configuration at C-22 and placement of the nitrogen atom with regard to the plane of the steroid.     

蝙蝠葛酚性碱对胃癌细胞SGC-7901 COX-2表达的影响

为探讨蝙蝠葛酚性碱(PAMD)抗胃癌的作用机理,通过实时定量PCR观察PAMD对胃癌细胞株SGC-7901 COX-2 mRNA表达的影响.结果表明,PAMD各剂量组均能下调COX-2 mRNA的表达,其中PAMD(20)剂量组下调COX-2的作用有统计学差异,且优于阳性对照组.PAMD抗胃癌的作用机理可能与其抑制COX-2基因表达有关.     

福建三尖杉中生物碱的高效液相分离与鉴定

分别用半制备型、分析型反相高效液相色谱法(HPLC)对福建三尖杉中的生物碱进行分离和检测,并用液质联用(LC-MS)、核磁共振(NMR)等对纯化样品进行结构分析．实验得到了4种含量较高的三尖杉生物碱,并检测到了其他微量生物碱4个．其中,碱(m／z)344和碱(m／z)330与具有相同相对分子质量的已知生物碱的^1H NMR数据差异较大．与传统方法相比,反相HPLC分离检测方法简单高效,且对环境友好,对寻找新的微量化合物、提高资源利用率有重要意义．     

分光光度法测定川产乌头属植物总生物碱的含量

根据二帖类生物碱和酸性染料溴甲酚绿在酸性缓冲液中形成的络合物能被氯仿提取,并且提取液在415 nm处具有吸收值的原理,运用酸性染料比色法测定了四川境内乌头属植物总生物碱的含量.乌头碱的标准曲线范围是8.8-52.8μg/mL(r=0.999 87,n=6),其平均加样回收率为99.548%.该方法灵敏度高、简便、准确快速.     

金钗石斛中生物碱提取的动力学分析

将金钗石斛用氨水浸润后,以氯仿为溶剂,在不同液固比、不同提取时间和不同提取温度下提取生物碱,以Fick第二定律为依据,以提取生物碱质量浓度为检测指标,求解提取动力学的表观传质速率方程、速率常数k、相对萃余率和表观活化能Ea等数值,建立金钗石斛生物碱提取过程的动力学模型.结果显示:在液固比为60,提取温度为60℃,提取时间为90 min时,所提取的生物碱质量浓度较高,金钗石斛生物碱提取过程的动力学基本符合一级动力学方程,在不同影响因素下,表观传质速率ln[C_∞/(C_∞-C_0)]、相对萃余率与时间t均有比较好的线性关系,提取动力学方程的活化能Ea为55.075 k J/mol.由此知金钗石斛生物碱提取过程的关键控制步骤为溶质的内扩散步骤.