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11.
采用NIR法和化学计量学方法构建了银杏叶片中的总黄酮醇苷和萜类内酯含量的定量分析模型。通过PLS建立数学模型,并对预测集样品进行预测。39份样品经交叉验证建立校正模型,RSMECV分别为0.104和0.063。R分别为0.978 8和0.961 9。用13份样品进行预测,R达0.919 9和0.931 8,RSMEP分别为0.107和0.105。该方法简便快速,结果准确,可应用于不同批次银杏叶片样品的进行快速检查或质量控制。 相似文献
12.
The variation of the brominated indole and diterpenoid content within single and different colonies of the bryozoan Flustra foliacea was investigated. The secondary metabolite profile and concentrations of individual components of F. foliacea samples were established using GC-MS. Samples from 17 different collecting sites were analyzed. The alkaloid and diterpene composition of F. foliacea varied greatly depending upon the site of collection. Investigation of F. foliacea samples from a single site (Helgoland, North Sea) over a period of time showed that the alkaloid and diterpenoid profile remained constant, however concentrations of individual components varied significantly. The alkaloid and diterpenoid composition of different segments of a single colony was found to be constant. Only small differences could be detected in the essential oil composition of different colonies and segments of single colonies of F. foliacea. Two of the F. foliacea alkaloids were found in the gastropods Hydrobia ulva and Gibbula cinerea, and one alkaloid in the common starfish Asteria rubens, all collected from the surface of the bryozoan. 相似文献
13.
In this paper, we fabricated hierarchical self-assembled hollow rose-like flower microspheres (HRFM) and hollow burr-like flower microspheres (HBFM) hydroxyapatite (HAP) using dehydroabietyl phosphate tri-ester (DDPT) as an organic phosphorus source, a regulating agent, and a soft template simultaneously via a one-step solvothermal method. The HBFM and HRFM have been explored for their application in drug delivery, using doxorubicin (DOX) as a drug model. The formation mechanisms of HRFM and HBFM were proposed on the basis of the electrostatic potential diagrams and self-assembled behavior of DDPT organic molecule. After the rosin-based terpene functional groups were incorporated, both HRFM and HBFM exhibited low cytotoxicity against Hela cell, pH-dependent sustained drug release properties, and high drug loading capacity. The drug-loading capacities of HBFM and HRFM were 116.6?mg?g?1 and 148.3?mg?g?1, respectively. Thus, the as-prepared HRFM and HBFM are promising for the applications in drug delivery. 相似文献
14.
This study quantifies emissions of hydrocarbon terpenes from the drying of sawdust in packed moving bed dryers, through the production chain to the finished pellets, and determines the parameters suitable for emission control. The terpene content in softwood sawdust and pellets was analyzed using gas chromatography. The distribution of VOC emissions over the bed was measured with a flame ionization detector. After drying, 30–40% of the initial terpenes remain in the wood, 20–30% remain after grinding, and 10–15% remain after pelleting. Dryer emissions correlate with residence time and final sawdust moisture content. Pellet press emissions correlate with pellet moisture content. 相似文献
15.
川渝地区野生大茶树的挥发性组分及萜烯指数分析 总被引:1,自引:0,他引:1
为分析川渝地区野生大茶树挥发性组分及其亲缘关系,利用同时蒸馏- 萃取(SDE)法对川渝地区野生大茶树资源茶鲜叶加工的烘青绿茶挥发性组分进行萃取,经GC-MS 技术进行分析,共检测出71 个化合物。其中含有芳樟醇及其氧化物、香叶醇、橙花醇、α- 萜品醇等醇类化合物,有β- 水芹烯、β- 香叶烯、柠檬烯、α - 雪松烯、石竹烯、α- 法呢烯等萜烯类化合物,有β- 柠檬醛、苯甲醛、(E)-2- 己烯醛等醛类物质,有棕榈酸甲酯、邻苯二甲酸二丁酯等酯类化合物,有顺- 茉莉酮、α- 紫罗酮等5 种绿茶典型的香气化合物,还有胺、烃、萘、蒽、酸等。萜烯指数(TI)分析表明,野生大茶树TI 高于野生大茶树子一代及福鼎大白茶。萜烯指数的变化可以作为鉴定茶树资源的分类依据之一。 相似文献
16.
17.
GENOMIC HARDWIRING AND PHENOTYPIC PLASTICITY OF TERPENOID-BASED DEFENSES IN CONIFERS 总被引:8,自引:0,他引:8
Over evolutionary history, conifers have faced a myriad of threats from phloem- and xylem-feeding insects, defoliating insects, and fungal pathogens. Among the trees defenses, terpenoids appear to play a major role by harming, disabling, deterring, repelling, or otherwise reducing the fitness of potential invaders. Each of the three classes of terpenoids in conifers, monoterpenes, sesquiterpenes, and diterpenes, are composed of a large number of representative compounds. In most cases, the presence of a particular terpenoid compound in the oleoresin or volatile emissions from a specific conifer can be accounted for by the expression of one of many committed terpene synthase (TPS) genes. However, while each TPS may produce one or a few major products, many produce a variety of minor products with relatively constant component ratios in the product blends. TPS genes exist in conifers in large and functionally diverse, yet monophyletic, gene families. Within these gene families, new biochemical functions of TPS appear to have evolved by gene duplication and changes in the amino acid sequence of the enzymes active site. In addition, TPS genes may be differentially expressed prior to, during, and following attack by insects or pathogens. Thus, while the production of any particular terpenoid is hardwired into a conifers genome, these trees have the capacity to change the mixture of terpenoids in oleoresin secretions and volatile emissions. Anatomical changes may also accompany induced terpenoid production, supplementing the plasticity of the molecular and biochemical events. 相似文献
18.
19.
α-蒎烯阳离子聚合工艺的改进 总被引:2,自引:0,他引:2
以A lC l3/SbC l3为催化剂,用SbC l3逐步滴加方式,通过两步聚合工艺制备了α-蒎烯树脂。通过正交实验,对α-蒎烯调控聚合的各影响因素进行了研究。结果表明,与传统的一步聚合工艺相比,该工艺在保持单体高转化率的同时,使聚合反应变缓,避免了由于反应过快而引起的聚合产物中低聚体含量高,Mn下降的现象;有效提高了聚合物的软化点;降低了聚合物的色值。在优化工艺条件下,催化剂用量比传统工艺减少30%以上,制得的α-蒎烯树脂软化点为138℃(环球法),色泽3(铁钴色),得率达81.0%,软化点提高8℃以上,色泽降低2级以上。产品各项指标均超过了我国行业标准LY/T1453—1999特级水平。 相似文献
20.
Tornambé G Cornu A Pradel P Kondjoyan N Carnat AP Petit M Martin B 《Journal of dairy science》2006,89(6):2309-2319
Changes of terpene content in milk from cows grazing natural diversified upland pasture were examined in this observational trial. A homogeneous plot divided into 2 subplots was used from May 31 to July 1, 2003 (first growth) and again from October 1 to October 7, 2003 (vegetative regrowth). Each subplot was grazed by 6 dairy cows in 2 ways: strip grazing (SG), with new allocations of pasture strips at 2-d intervals, and paddock grazing (PG). The PG subplot was divided into 3 paddocks and the cows were moved to a new paddock on June 13 and June 24, 2003. Milk from the 6 cows was collected twice a week, pooled, and used for terpene analyses by dynamic headspace gas chromatography-mass spectrometry system. Twenty mono- and 23 sesquiterpenes desorbing from the milk fat were separated. The most abundant monoterpenes were β-pinene, α-pinene, γ-terpinene, limonene, α-tujene, terpinolene, and α-phellandrene. The most abundant sesquiterpenes were β-caryophyllene, α-copaene, β-cedrene, transmuurola-4-(14)-5-diene, β-bisabolene, and δ-cadinene. Both mono- and sesquiterpenes in SG milk increased across time with an 8-fold increase in total terpenes in milk from the beginning to the end of June. In parallel, dicotyledons, including the main terpene-rich plants, increased from 17 to 31% of total biomass of the vegetation and the development of Dactylis glomerata progressed from boot to ripening stage. The terpenes in PG milk were equivalent to those in SG milk for the first paddock at the beginning of June and remained constant or doubled for the sum of mono- and sesquiterpenes, respectively. The lower variability of the PG milk terpene content could be related to the opportunity that PG cows had to choose ingested herbage, whereas the SG cows had limited choice within the smaller allocated pasture strips. Milk from cows grazing regrowth pastures in October contained low levels of terpenes, and values were similar for PG and SG milks. Change in the sum of monoterpenes is representative of changes for most monoterpenes (except for limonene) and, conversely, the change in the sum of sesquiterpenes mainly reflected changes in β-caryophyllene and α-copaene. In addition to effects of botanical composition of pasture, it appears that terpene content in milk may vary according to factors linked to grazing management that need more intensive study. Nevertheless, current results raise questions about the precision of terpenes as feed tracers. 相似文献