杭州墨红净油挥发组份的研究

本文采用气相色谱—质谱联用技术,对杭州产的墨红花净油挥发组份进行分析,在90℃以下蒸馏液中,分离出54个组份,鉴定出其中30个,占总色谱峰面积的89.1％。主要成份为:β-苯乙醇(20.71％)、柠檬烯(12.49％)、苯甲醇(10.81％)、β-月桂烯(6.04％)、香茅醇(5.86％)、正乙醇(5.03％)、芳樟醇(3.84％)、2-异丙基甲苯(3.43％)、苯甲醛(2.42％)、丙酮(1.81％)、4-异丙基苯甲醇(1.57％)、甲酸苯乙酯(1.21％)和氧化芳樟醇(呋喃型,1.15％)等。     

珍稀濒危植物单性木兰种皮的挥发性成分分析

采用水蒸汽蒸馏法提取单性木兰种皮的挥发组分,用GC-MS分别定性定量分析了提取的油层精油和溶解在水中的化学成分。结果表明,挥发组分的提取率为4.2%,其中,油层精油得率为3.5%,主要成分中萜烯类化合物多,含量高,其中罗勒烯37.3%、D-苧烯9.03%、对-伞花烯8.10%、β-月桂烯7.79%、β-反-罗勒烯4.08%、对-孟-1-烯4.00%、α-侧柏烯3.11%;水层乙醚萃取率0.7%,其中α-松油醇6.13%、对-伞花烃5.57%、D-苧烯5.33%、6-甲基-3,5-庚二烯-2-酮4.44%、4-甲基-4-戊烯-2-酮4.16%。     

华山松球果挥发性萜类成分研究

选择7月份的华山松球果。用GC-MS分析了健康果和受害果萜类挥发物成分。结果表明,华山松球果挥发成分25种,其中单萜17种。倍半萜8种,7种主要成分均为单萜组分,它们是a-蒎烯、β-非兰烯／4-侧柏烯、β-蒎烯、β-香叶烯、D-柠檬烯和异松油烯。球果受害后,单萜、倍半萜种类没有变化,除β-蒎烯含量减少外,单萜总量和各组分的含量明显增加。其中β-非兰烯／4-侧柏烯含量增加最多;而倍半萜各组分相对含量变化很小。同时,比较了水蒸气蒸馏和二氯甲烷浸提的分析结果。认为水蒸气蒸馏法不适合华山松球果挥发成分的研究。     

佛手挥发油特征化学成分群GC-MS研究

目的:分析6个不同产地佛手挥发油的化学成分,确定其特征化学指标成分群.方法:采用水蒸气蒸馏法提取佛手挥发油.运用气相色谱质谱联用技术(GC-MS),结合计算机检索对其化学成分进行分离和鉴定,得到其共有的特征性化学成分群,用色谱峰面积归一化法计算各组分的相对含量.结果:从广东、四川、金华、广西、安徽佛手的挥发油中鉴定16种共有特征成分,按保留时间的先后顺序分别为:α-水芹烯、α-蒎烯、β-蒎烯、β-月桂烯、α-萜品油烯、邻伞花烃、柠檬烯、顺式-β-罗勒烯、反式-β-罗勒烯、γ-萜品烯、γ-萜品油烯、乙酸芳樟酯、顺式-水合桧烯、α-萜品醇、β-柠檬醛、α-柠檬醛,其占总峰面积的的比例大于82.9%;其中柠檬烯和γ-萜品烯是主要成分,两者峰面积占总峰面积的比例大于65%.结论:所建立的特征成分群能充分地袁征佛手挥发油化学组成,可以为佛手挥发油的质量评价提供参考.     

‘长营’橄榄果实挥发性成分分析

采用固相微萃取法和气相色谱-质谱联用法,对福建闽侯地区的优良橄榄品种'长营'橄榄(Canarium album'Changying')果实的香气成分进行分析,分离出22个峰,确认了22种化学物名称及其相对含量.结果表明:'长营'橄榄挥发油主要成分为石竹烯、八氢-7-甲基-3-亚甲基-4-异丙基-1H-五环[1,3]三环[1,2]苯、1,2,3,5,6,8a-六氢-4,7-二甲基-1-异丙基萘、古巴烯、α-石竹烯、丁基羟基甲苯、β-蒎烯、α-毕澄茄油烯等,其中石竹烯含量最高,达42.40%.比较'冬节圆'橄榄、'三棱'榄橄的挥发物成分,表明橄榄挥发物的主要成分为烯类,但成分各不相同.可见不同品种或不同产地的橄榄香气成分差异较大.     

腊梅花蕾挥发性化学成分分析

利用两种不同萃取条件的超临界CO2流体萃取法提取腊梅花蕾挥发油.应用GC-MS技术对两组挥发油成分进行分离和鉴定,分别分离得到两组挥发油中的39、41个色谱峰,通过NIST2005标准谱库检索和WLEY质谱库比较,共鉴定了其中45种化学成分.结果表明:腊梅花蕾挥发油主要成分为芳樟醇、邻苯二甲酸二辛酯、β-月桂烯、桧烯、橙花叔醇、苯甲醇、己酸乙酯、β-蒎烯和榄香醇;不同萃取条件下腊梅花蕾挥发油成分差异明显.     

脐橙果皮挥发油成分分析及在卷烟中的加香应用

为研究脐橙果皮挥发油化学成分及其对提高卷烟吸食品质效果,采用水蒸汽蒸馏法和超声波萃取法结合GC-MS对脐橙果皮挥发油成分进行分析和卷烟加香试验。鉴定出水蒸汽蒸馏法和超声波萃取法二者共有主要成分25种,超声波萃取法所得产物相对含量高于水蒸汽蒸馏法,前者方法较优。主要有柠檬烯,β-芳樟醇,β-月桂烯,6,6-二甲基-2-亚甲基二环庚烷,4(10)-侧伯烯,辛醛等。脐橙果皮挥发油具有明显降低卷烟刺激性、柔和烟香、改善口感和增加烟气甜润度等效果。     

不同品种番石榴花的挥发性成分分析

为探究番石榴(Psidium guajava)花挥发性成分组成,采用顶空/气相色谱-质谱联用技术对10个番石榴品种(‘翠玉’、‘帝王’、‘本土’、‘红叶’、‘粉红蜜’、‘珍珠’、‘西瓜’、‘水蜜’、‘木瓜’和‘红宝石’)花的挥发性成分进行鉴定分析。结果表明,10个品种共检出相对含量在0.1%以上的挥发性成分43种,包含共有成分10种,以萜烯类化合物(89.77%～97.40%)为主。β-石竹烯、β-罗勒烯、桉叶油醇和D-柠檬烯为花主要挥发性成分。影响品种间挥发性成分差异的成分主要有7种,分别为α-蒎烯、β-罗勒烯、D-柠檬烯、3-蒈烯、香树烯、β-长叶蒎烯和1-异丙基-4,7-二甲基-1,2,3,5,6,8a-六氢萘。按照香气相似性,‘翠玉’和‘帝王’归为一类,‘水蜜’和‘本土’归为一类,‘粉红蜜’、‘西瓜’、‘红叶’、‘木瓜’和‘红宝石’归为一类,‘珍珠’为单独一类。不同品种番石榴花挥发性成分存在相似性和差异性,为番石榴花混合采摘及后期个性化开发利用提供理论基础。     

SPME-GC/MS 联用分析六堡茶茶花香气成分

该研究采用顶空固相微萃取—气相色谱/质谱联用技术,对六堡本地三种茶树花的香气成分进行了分析。结果表明：大叶种茶树花中共鉴定出香气成分37种,主要为苯乙酮、4-甲基-1,5-庚二烯、苯甲酸甲酯、愈创木二烯、顺式芳樟醇氧化物、雪松烯、水杨酸甲酯、D-杜松烯、1-氨基-环戊醇、除虫菊酮,占总相对含量的89.48％;中叶种共鉴定出32种成分,主要为苯乙酮、紫苏烯、顺式-3-蒈烯、顺式α-榄香烯、苯甲酸乙酯、塞瑟尔烯、α-蒎烯、新丁香三环烯、衣兰烯、顺式芳樟醇氧化物,占总相对含量的83.88％;小叶种的茶树花中共鉴定出45种香气成分,主要为苯乙酮、紫苏烯、罗勒烯、顺式α-榄香烯、2-异丙基-5-甲基-9-亚甲基-二环[4.4.0]癸-1-烯、荜澄茄油烯醇、α-菖蒲二烯、α-红没药烯、衣兰烯、苯甲酸乙酯、白菖油萜和α-杜松烯,占总相对含量的82.34％。苯乙酮为三种茶树花共有的主要成分,分别占总相对含量的60.70％、42.46％和39.91％,这成分与其他成分一起构成了3个品种明显不同的茶树花花香。该研究结果为六堡茶树花的深加工提供了依据。     

基于保留指数的GC-MS分析毛蕊花挥发性成分

采用水蒸气蒸馏法采集毛蕊花中的挥发性成分,气相色谱/质谱联用技术(GC-MS)结合保留指数对其进行分析鉴定,共鉴定出38种主要的挥发性成分,含量较高的组分分别为柠檬烯26.57%、茴香酮24.81%、桉叶素7.24%、石竹烯氧化物5.91%和蒎烯4.72%。GC-MS结合保留指数对毛蕊花挥发性成分进行定性分析,使定性结果更为准确。     

Analysis of high-resolution melting (thermal dispersion) of DNA. Methods

We describe the capabilities of a method for obtaining high-resolution melting profiles of short, homogeneous DNAs using a thermo-differential absorbance technique. The absorbance difference of two identical DNA solutions, raised linearly in temperature and maintained at a constant temperature difference, is monitored using a double-beam spectrophotometer. A specially constructed temperature controller and cell holder enable the temperature of the DNA samples to be controlled and monitored directly. A heating rate of 6.75°C/hr has been found to give reproducible results at ionic strengths > 0.01M. A method of reconstructing the true derivative from experimental data using a Taylor series expansion is described and shown to work well when the difference in temperature between samples is in the range of 0.2°C. Reconstructed derivative profiles are further analyzed by deconvolution into distinct Gaussian components. The melting profile of PM-2 DNA is shown to consist of 14 components, while the much longer lambda DNA yields 55. Related techniques such as data management and analysis for the fractional G·C content of specific domains are also described.     

1H NMR Spectroscopy Profiling of Metabolic Reprogramming of Chinese Hamster Ovary Cells upon a Temperature Shift during Culture

We report an NMR based approach to determine the metabolic reprogramming of Chinese hamster ovary cells upon a temperature shift during culture by investigating the extracellular cell culture media and intracellular metabolome of CHOK1 and CHO-S cells during culture and in response to cold-shock and subsequent recovery from hypothermic culturing. A total of 24 components were identified for CHOK1 and 29 components identified for CHO-S cell systems including the observation that CHO-S media contains 5.6 times the level of glucose of CHOK1 media at time zero. We confirm that an NMR metabolic approach provides quantitative analysis of components such as glucose and alanine with both cell lines responding in a similar manner and comparable to previously reported data. However, analysis of lactate confirms a differentiation between CHOK1 and CHO-S and that reprogramming of metabolism in response to temperature was cell line specific. The significance of our results is presented using principal component analysis (PCA) that confirms changes in metabolite profile in response to temperature and recovery. Ultimately, our approach demonstrates the capability of NMR providing real-time analysis to detect reprogramming of metabolism upon cellular perception of cold-shock/sub-physiological temperatures. This has the potential to allow manipulation of metabolites in culture supernatant to improve growth or productivity.     

Growth temperature regulation of host-specific modifications of rhizobial lipo-chitin oligosaccharides: the function of nodX is temperature regulated

Lipo-chitin oligosaccharides (LCOs) are usually produced and isolated for structural analysis from bacteria cultured under laboratory rather than field conditions. We have studied the influence of bacterial growth temperature on the LCO structures produced by different Rhizobium leguminosarum strains, using thin-layer chromatographic, high-performance liquid chromatographic, and mass spectrometric analyses. Wild-type R. leguminosarum bv. viciae A1 was shown to produce larger relative amounts of nodX-mediated, acetylated LCOs at 12 degrees C than at 28 degrees C, indicating that the activity of nodX (a gene encoding an LCO O-acetyl transferase) is temperature dependent. Interestingly, symbiotic resistance genes sym1 and sym2 found in primitive pea cultivars are also temperature sensitive, only being active at low temperatures, at which they block nodulation by R. leguminosarum bv. viciae strains lacking nodX. We therefore propose that the gene-for-gene relationship between plant and bacterium has a temperature-sensitive mechanism as an adaptation to environmental conditions. An R. leguminosarum bv. trifolii strain was also shown to produce larger relative amounts of nodX-mediated, acetylated LCOs at 12 degrees C than at 28 degrees C. The major components synthesized by the two strains are produced at both temperatures but in different relative amounts, while some minor components are only produced at one of the two temperatures.     

连续温度变化对β-1,3-葡聚糖酶酶解酵母β-葡聚糖的影响

为了探索反应温度对产物组分的影响,利用自制连续变化的温度梯度实验装置,研究了22 ℃~60 ℃ (±0.1 ℃) 区间内温度对一内切β-1,3-葡聚糖酶酶解酵母β-葡聚糖的影响,获得了酶解过程多点温度特性数据。分析表明：该酶酶解酵母β-葡聚糖的活化能为84.17 kJ/mol;以产物积累表示的最适酶解温度随时间延长呈指数下降;酶解产物组分受温度的影响,低温较高温获得的寡糖链长,高温区大于46 ℃可以获得以昆布二糖、昆布三糖为主的组分,而低温区小于30 ℃可以获得昆布五糖及更大分子量的产物。研究结果可为寡糖     

Dynamic properties of the active site of azurin studied by the temperature dependence of the optical spectrum

Summary We report the optical absorption spectra of azurin (Pseudomonas aeruginosa) in the temperature range 290-20 K. The samples used are protein aqueous solutions containing 65% (by Vol.) glycerol as cryoprotectant. The measured spectra are deconvoluted in gaussian components and the temperature dependence of the zeroth, first and second moment of the observed bands is analyzed using the harmonic Franck-Condon approximation for the coupling between electronic transitions and nuclear vibrations. The analysis provides information on the stereodynamic properties of the active site of this protein. The possible functional relevance of these results is also suggested.     

西洋参有效成分与气候生态因子的关系

通过回归分析、灰色关联分析等方法系统地分析了气候生态因子对西洋参有效成分含量的影响,结果表明：温度和日照是影响西洋参总皂甙含量的主要气候因子;其总皂甙的含量与总氨基酸的含量呈显著负相关,故气候因子对二者的作用方向相反;影响西洋参醚浸出物、醇浸出物以及水溶性浸出物含量的主要气候因子均为气温日较差和日照时。     

Seasonal changes in light and temperature affect the balance between light harvesting and light utilisation components of photosynthesis in an evergreen understory shrub

In a temperate climate, evergreen species in the understory are exposed to large changes in photosynthetic photon flux density (PPFD) and temperature over the year. We determined the photosynthetic traits of leaves of an evergreen understory shrub Aucuba japonica at three sites at monthly intervals: understorys of a deciduous forest; an evergreen forest; and a gap in a mixed forest. This set up enabled us to separate the effects of seasonal change in PPFD and temperature on photosynthetic acclimation under natural conditions. The effects of PPFD and temperature were analysed by simple and multiple regression analyses. The amounts of light utilisation components (LU), represented by nitrogen and rubisco contents per area, were higher in winter, when temperature was low and PPFD was high. The LU relative to the amount of light harvesting components (LH), represented by chlorophyll a/b and rubisco/chlorophyll ratios, and the inverse of chlorophyll/nitrogen ratio were also higher in winter. We quantified the effects of PPFD and temperature on the LU and LH components. Across sites PPFD had stronger effects than air temperature, while within a site temperature had stronger effects on photosynthetic acclimation. We concluded that the photosynthetic apparatus is strongly affected by the prevailing PPFD at the time of leaf development. Within a given light regime, however, plants acclimated by increasing LU relative to LH primarily in response to temperature and to a lesser extent to PPFD.     

Effects of light dynamics on coral spawning synchrony

Synchrony of spawning in many hermatypic corals, typically a few nights after the full moon, is putatively dependent on solar and lunar light cycles in conjunction with other possible cues such as tides and temperature. We analyze here the contributions of separate components of light dynamics, because the effects of twilight and lunar skylight on coral spawning synchrony have previously been conflated and the alternative hypothesis that these components have differential contributions as proximate cues has not been tested. Moonlight-dependent changes in spectra during twilight, rates of decreasing twilight intensities, and changes in lunar photoperiod were experimentally decoupled using programmed light-emitting diodes and compared for their separate effects on spawning synchrony in Acropora humilis. Effects on synchrony under the control of synthetic lunar cues were greatest in response to changes in lunar photoperiod; changes in light intensities and spectra had lesser influence. No significant differences among treatment responses were found at the circa-diel time scale. We conclude that spawning synchrony on a particular lunar night and specific time of night is a threshold response to differential periods of darkness after twilight that is primarily influenced by lunar photoperiod and secondarily by discrete optical components of early nocturnal illumination.     

Shape and size variation on the wing of <Emphasis Type="Italic">Drosophila mediopunctata</Emphasis>: influence of chromosome inversions and genotype-environment interaction

The second chromosome of Drosophila mediopunctata is highly polymorphic for inversions. Previous work reported a significant interaction between these inversions and collecting date on wing size, suggesting the presence of genotype-environment interaction. We performed experiments in the laboratory to test for the joint effects of temperature and chromosome inversions on size and shape of the wing in D. mediopunctata. Size was measured as the centroid size, and shape was analyzed using the generalized least squares Procrustes superimposition followed by discriminant analysis and canonical variates analysis of partial warps and uniform components scores. Our findings show that wing size and shape are influenced by temperature, sex, and karyotype. We also found evidence suggestive of an interaction between the effects of karyotype and temperature on wing shape, indicating the existence of genotype-environment interaction for this trait in D. mediopunctata. In addition, the association between wing size and chromosome inversions is in agreement with previous results indicating that these inversions might be accumulating alleles adapted to different temperatures. However, no significant interaction between temperature and karyotype for size was found--in spite of the significant presence of temperature-genotype (cross) interaction. We suggest that other ecological factors--such as larval crowding--or seasonal variation of genetic content within inversions may explain the previous results.     

RETHINKING ACCLIMATION OF GROWTH AND MAINTENANCE RESPIRATION OF TOMATO IN ELEVATED CO2: EFFECTS OF A SUDDEN CHANGE IN LIGHT AT DIFFERENT TEMPERATURES

Aims Changes in light and temperature are among the most common and most profound environmental perturbations. The independent effects of light and temperature on photosynthesis and respiration are well studied in single leaves, but are less well studied in whole plants. The short and long term influence of light and temperature on carbon use efficiency is also poorly understood, and is commonly modeled to remain constant over a wide range of conditions. We sought to determine the primary effects of changing light at two growth temperatures on photosynthesis, respiration, and their balance, as defined by carbon use efficiency. Methods We separated respiration into growth and maintenance components using whole-canopy gas-exchange in an elevated CO₂ environment in a controlled environment, and supplemented that information with tissue analysis. Important findings Decreases in light level decreased carbon use efficiency through a reduction in the maintenance coefficient, increased the growth coefficient, and reduced partitioning of N in protein. Growth temperature did not significantly affect either maintenance or growth respiration coefficients, suggesting that long-term temperature responses can differ greatly from short-term observations.