白皮松针叶内皮层中具凯氏带的证据

利用荧光显微镜对白皮松（Pinus bungeana Zuce.)针叶内皮层结构进行深入观察,确认内皮层径向壁和横向壁上具有能够激发荧光的带状结构;用纤维素酶和果胶酶对内皮层充分酶解分离后,首次从叶中得到类似于根部内皮层特有的网状结构。应用傅立叶变换红外光谱分光术（FTIR）对网状结构进行化学成分鉴定,其吸收光谱的分析结果表明,针叶内皮层细胞壁带状结构部分含有木质素,木栓质,纤维素和细胞壁蛋白等,而这些成分与针叶维管组织的成分不尽相同,上述证据表明,白皮松针叶内皮层细胞壁具有与根部内皮层相似的凯氏带结构。     

白皮松针叶内皮层在盐胁迫中的屏障作用研究

应用荧光显微技术、傅里叶变换显微红外光谱分析(FTIR)、扫描电镜及X-射线能谱微区分析等手段,对白皮松(Pinus bungeana)子叶、初生叶及2a生针叶内皮层细胞径向壁的显微结构特征、化学成分,以及在叶子横切面上Na和Cl的微区分布进行分析。通过荧光显微观察发现,白皮松子叶内皮层不具凯氏带,而初生叶及2a生针叶均存在凯氏带加厚现象。根据FTIR的检测结果显示:子叶内皮层细胞径向壁不含木栓质或极少,2a生针叶内皮层细胞径向壁木栓质含量高于初生叶。对相应区域的X射线微区分析表明,子叶内皮层对Na和Cl在质外体运输中不起障碍作用,而初生叶与2a生针叶内皮层阻碍Na和Cl以质外体途径进入维管组织。研究结果表明:具凯氏带加厚的内皮层细胞壁中木栓质含量决定其在质外体运输过程中的生理功能。     

FT-IR光谱在电离辐射作用于微生物研究中的应用

傅里叶变换红外光谱(Fourier transform infrared spectroscopy,FT-IR)是一种很有用的生物分析检测技术,通过FT-IR光谱技术可以得到有关蛋白质、脂类、核酸和多糖等微生物和细胞各类组成成分的信息。基于同步辐射光源的显微FT-IR光谱具有更高的空间分辨率和更快的测量速度,因而在生物学研究中具有进行快速、实时、动态和无损检测等优势。本文介绍了FT-IR光谱技术在微生物及电离辐射作用于微生物引起的生物学效应研究中的应用,并对该领域未来研究的发展趋势进行了展望。     

傅里叶变换红外技术研究Cl~-通过红细胞膜带Ⅲ蛋白时的构象变化

用傅里叶变换红外光谱技术研究Ｃｌ-通过完整红细胞、红细胞血影、重组带Ⅲ蛋白脂质体三种体系中的膜带Ⅲ蛋白时的二级结构变化。结果证明：Ｃｌ~-通过膜带Ⅲ蛋白,导致其ａ-螺旋增加,β-结构减少,以扫描隧道显微术直接观察到Ｃｌ~-通过前后、膜带Ⅲ蛋白的分子形态有改变。     

基于FTIR的三倍体罗汉果花粉直感效应研究

以四个品系的三倍体罗汉果雌株为材料,用五种不同的二倍体雄花分别对其授粉,利用傅里叶变换红外光谱法(FTIR)测定了其子代果实的红外光谱,并运用主成分分析和聚类分析研究了授粉雄花对子代果实化学成分的影响。结果表明:不同雄花授粉后,雌株F302、F323和F322各子代果实红外光谱中1 050 cm-1波数附近甜苷物质特征吸收峰的峰高有显著或极显著差异,雌株F311子代无籽果实的差异不显著;同时五种授粉雄花分别对雌株F302、F323、F322和F311子代果实在主成分二维投影图和聚类图中的排序也有明显的影响,但对不同品系雌株子代果实的排序影响不同,从而说明三倍体罗汉果的甜苷物质含量和整体成分含量均有较为明显的花粉直感效应,并且存在品种特异性。     

7份不同产地野生甜茶FTIR指纹图谱及其甜茶苷含量比较分析

本研究运用傅里叶变换红外光谱法,采集7份不同产地甜茶叶片的FTIR图谱,结合相关性系数和二阶导数方法对其红外光谱特征进行指认,并比较各供试甜茶的红外指纹图谱及甜茶苷含量间差异。研究结果表明,依据不同产地甜茶红外指纹图谱特征,可以将其归结为3大类Ⅰ类包括:金秀、荔浦、平南、象州及永福等地的甜茶,相关系数在0.992～0.999间;Ⅱ类包括第Ⅰ类型以外的广西其它采集地区的甜茶,相关性系数主要集中在0.984～0.990之间;Ⅲ类包括广东分布区,该区甜茶与广西分布区甜茶的相关系数均在0.986以下。供试甜茶与甜茶苷标准品的光谱特征比较结果表明,不同产地甜茶甜茶苷含量有较大差异。其中,广西金秀和广西平南产的甜茶叶片中甜茶苷含量最高,广西岑溪产的甜茶叶片中甜茶苷含量最低。所以,运用FTIR技术可以对不同产地甜茶进行分析并快速鉴别出不同产地甜茶中甜茶苷含量差异。本研究结果对广西地区甜茶的引种驯化和合理开发利用有一定指导意义。     

姜科植物的FTIR鉴别分类研究

红外光谱图峰形峰位大体一致,所含化学成分基本相同,是由碳水化合物、蛋白质、脂类等生物大分子振动谱带构成。该研究采用傅里叶变换红外光谱技术结合聚类分析,对姜科植物姜亚科2族6属29种植物进行光谱测试,分析比较姜科同族不同属和同属不同种植物在红外谱图上表现出的差异。将1800~1000 cm-1进行二阶导数处理,并对差异较大的1750~1400、1200~1000 cm-1两个波段分别进行比较分析,用吸光度比值A1516/A3424、A1449/A3424来反映二苯基庚烷和姜辣素的相对含量,再将二阶导数据进行系统聚类。结果表明：姜科植物的主要化学成分姜辣素与二苯基庚烷类化合物的相对含量在族属间和属种间有差异,两种化合物的相对含量在同族不同属植物中差别很大,在同属不同种植物中大体一致;姜科植物的糖类化学成分以单糖和多糖为主;在族属级的水平分类中,2族6属姜科植物的分类与传统分类结果基本吻合,并从光谱角度建议心叶凹唇姜的族级分类应该深入研究。通过研究可知,傅里叶变换红外光谱技术结合聚类分析法可以应用于姜科植物的分类。该研究结果为姜科植物的分类系统学提供了参考。     

盐酸比哌立登与人血清蛋白的相互作用研究

目的:研究盐酸比哌立登(BH)与人血清蛋白(HSA)的相互作用,为阐明其在体外的代谢过程、作用机理提供理论依据。方法:本研究采用紫外-可见分光光度法、荧光光谱法、傅里叶变换红外光谱(FTIR)法及分子对接模拟等方法,在不同温度下,测定BH与HAS的紫外吸收光谱变化、结合常数、结合位点,蛋白质二级结构变化和分子模拟对接情况。结果:在25℃时,BH与HSA的结合常数KA为2.71×10~3 L/mol,结合位点数目是0.86;在37℃时,结合常数KA为1.58×10~3 L/mol,结合位点数目为0.82。BH使得HSA的荧光波长向短波长方向蓝移;BH可导致HSA的α-螺旋向无规卷曲的转变。结论:BH与HAS通过氢键和范德华力相互作用,导致HSA酪氨酸残基周围内环境被破坏,环境极性减弱,疏水性增加,同时还会导致HSA荧光静态猝灭。     

坡度和埋深对橡胶林凋落叶分解及红外光谱特征的影响

橡胶树凋落叶在橡胶林生态系统养分循环中起着重要的作用,研究凋落叶的分解和养分释放特性及其影响因素,对资源的循环利用及指导高效施肥具有重要意义。在海南省天然橡胶主产区选取橡胶林地进行凋落叶原位分解试验,研究坡度和埋深对橡胶树凋落叶干物质分解特性、养分元素释放规律及其物质成分红外光谱特征的影响。结果表明,凋落叶分解速率明显受到坡度和深度的影响;分解9个月后,干物质残留率高低顺序为坡地覆盖(39.6%)平地覆盖(26.8%)平地埋深(11.2%)坡地埋深(6.9%);凋落叶的损失符合Olsen指数衰减模型(P0.01),各处理凋落叶干物质分解95%所需要的时间分别为29.3、20.5、12.8和13.2个月;各处理C/N比从最初的25.1下降到12.7、14.4、16.2和16.9。分解期间各处理养分残留率差异显著(P0.05);分解9个月后,坡地覆盖处理S-I养分元素C、N、P、K、Ca、Mg的残留率最高,分别为10.9%、21.6%、10.7%、9.7%、10.4%、7.9%,而坡地埋深处理S-II最低,分别为3.8%、6.5%、3.4%、2.3%、0.8%、2.1%。傅里叶红外光谱(FTIR)分析显示,凋落叶分解前后在3387 cm~(-1)、1734 cm~(-1)处的吸收峰强度明显减弱,表明纤维素、半纤维素、木质素、多糖、脂肪族等碳水化合物遭到分解;1050 cm~(-1)处的吸收峰向低频方向位移了17 cm后变为1033 cm~(-1),表明分解破坏了凋落叶原有的可溶性糖和纤维素C—C键和C—O键伸缩振动。综上所述,埋深处理有利于加速凋落叶物质分解和养分元素释放速率;建议橡胶树生产中将凋落叶与表土混合或压青处理,提高橡胶林养分循环效率。     

N+注入选育白腐菌及其降解油菜秸秆木质纤维素的研究

以白腐菌WY01为出发菌,利用N＋注入技术选育出一株遗传性状稳定的漆酶高产诱变菌株WY02,经过60 d的发酵培养,其产酶量由出发菌的13.75 U/g增加到52.5 U/g,即产酶量提高了2.82倍;诱变菌株WY02对油菜秸秆中的木质素、半纤维素和纤维素的降解率分别为54.1%,39.1%,32.8%,用红外光谱法（IR）分析经诱变菌株降解后的油菜秸秆中木质素官能团的变化,用于阐明诱变菌株对油菜秸秆中木质素的生物降解机制。结果表明：油菜秸秆经白腐菌诱变菌株降解后,其木质素含量明显降低。木质素与苯环相连的C=O键、木质素侧链上CH2结构以及木质素单体（紫丁香基和愈创木基）被部分降解,木质素的苯环结构遭到一定程度的破坏。     

华山松大小蠹及其伴生蓝变真菌对华山松木质部危害的解剖学特征

为揭示华山松大小蠹和伴生蓝变真菌引起秦岭华山松枯萎的机制,选择秦岭北坡沣峪林场境35年树龄的健康华山松Pinus armandi为研究对象,对接种华山松大小蠹Dendroctonus armandi及与其伴生的蓝变真菌Ceratocystis polonica引起的寄主树木木质部形态变化进行了解剖观察。结果表明：接种致病性蓝变真菌C. polonica 1周后的4株华山松 的木质部组织内,蓝变区域显著增加,4～6周后蓝变区域不再增加; 而在接种无菌琼脂的2株对照华山松的木质部组织内,没有检测到蓝变区域。研究结果提示蓝变真菌C. polonica是致死秦岭华山松的重要病原菌,该伴生菌随华山松大小蠹入侵健康寄主华山松木质部组织,在木质部定居并分解木质部,堵塞树脂道,致使寄主华山松树脂代谢和水分代谢紊乱。该研究结果表明,虽然华山松大小蠹长期以来被认为是致死华山松的毁灭性小蠹虫,但是其共生蓝变真菌C. polonica对成熟华山松的致害作用不应该被忽视。     

华山松叶绿素荧光诱导动力学参数的地理变异及其与树高生长的关系

 利用叶片体内荧光测定技术,检测了南北5个地区华山松种源的荧光诱导动力学参数。结果表明,南方种源具有较强的最大荧光(Fm)和可变荧光(Fv),其光系统Ⅱ(PSⅡ)的潜在活性(Fv／Fo)与原初光能转换效率(Fv／Fm)也明显高于北方种源,并与其树高生长成正相关。另一方面,北方种源的非光化学荧光猝灭系数(QN)比南方种源要大,与它们的树高生长成反相关,而与纬度成正相关。这些实验结果说明,利用荧光诱导动力学技术,可以检测华山松的生长量潜力,在华山松种源选择中有较大的应用前景。     

Vibrational spectroscopy to study the properties of redox-active tyrosines in photosystem II and other proteins

Tyrosine radicals play catalytic roles in essential metalloenzymes. Their properties—midpoint potential, stability…—or environment varies considerably from one enzyme to the other. To understand the origin of these properties, the redox tyrosines are studied by a number of spectroscopic techniques, including Fourier transform infrared (FTIR) and resonance Raman (RR) spectroscopy. An increasing number of vibrational data are reported for the (modified-) redox active tyrosines in ribonucleotide reductases, photosystem II, heme catalase and peroxidases, galactose and glyoxal oxidases, and cytochrome oxidase. The spectral markers for the tyrosinyl radicals have been recorded on models of (substituted) phenoxyl radicals, free or coordinated to metals. We review these vibrational data and present the correlations existing between the vibrational modes of the radicals and their properties and interactions formed with their environment: we present that the ν_7a(C-O) mode of the radical, observed both by RR and FTIR spectroscopy at 1480-1515 cm⁻¹, is a sensitive marker of the hydrogen bonding status of (substituted)-phenoxyl and Tyr, while the ν_8a(C-C) mode may probe coordination of the Tyr to a metal. For photosystem II, the information obtained by light-induced FTIR difference spectroscopy for the two redox tyrosines Tyr_D and Tyr_Z and their hydrogen bonding partners is discussed in comparison with those obtained by other spectroscopic methods.     

Geographical Variation in the Characteristics of Absorption Spectra and Fluorescence Spectra of Pinus armandi

By measuring the derivative absorption spectra of chloroplasts of different populations of Pinus armandi Franch., it was found that southern populations maintained higher absorption at 680 nm than at 670 nm, but some of the northern populations deviated the maximum absorption from 680 nm to 670 nm, which indicated that the activity of PS Ⅱ in some of the northern populations declined. Clear geographical differences also have been found in the positions of emission peaks of PS Ⅰ and PS Ⅱ in the fluorescence emission spectra at 77 K. Analysis of the fluorescence excitation spectra at 77 K revealed geographical changes in the absorption.status of Chl a. Besides, the experimental results indicated that the intact needles of Pinus armandi are not ideal materials to be used in detecting the geographical variation in photochemical reaction process because the presence of thicker coat, resin etc. can conceal the spectral differences in different populations.     

傅里叶变换红外光谱(FTIR)技术对滇龙胆组织培养的研究

野生药用植物资源的不断减少,使得寻找其原植物的合适替代品显得尤为重要。利用组培材料代替野生药用植物作为药源已取得重大进展,但利用傅里叶变换红外光谱(Fourier transform infrared spectroscopy,FTIR)技术筛选合适的组培材料作为野生药用植物替代资源方面的应用鲜有报道。本研究采用FTIR结合偏最小二乘判别分析(partial least squares discriminant analysis,PLS-DA)对滇龙胆组织培养形成的愈伤组织(肉质部、茎、叶)、增殖苗(肉质部、茎、叶)、生根苗(根、茎、叶)进行比较。结果显示:(1)从原始FTIR光谱图上看,滇龙胆肉质部和根部峰形相似,茎和叶峰形相似;(2)二阶导数光谱图扩大了样品间的差异。在龙胆苦苷的主要吸收峰1612 cm-1附近,吸收峰强度依次为:生根苗叶增殖苗叶和生根苗茎增殖苗茎愈伤组织叶,愈伤组织茎及肉质部、增殖苗肉质部和生根苗根部在该处无吸收峰;(3)PLS-DA得分图表明,同一组培阶段相同组织部位样品聚集在一起,而愈伤组织、增殖苗、生根苗及其各组织部位能够较好的分开。其中:肉质部、根部与茎叶之间距离较远,表明其化学成分和含量可能差异较大;肉质部和根部样品间距离较近,茎和叶样品间距离也较近。二阶导数光谱图显示,组培材料有望代替其原植物满足药用需求;若以龙胆苦苷含量为评价对象,生根苗叶则可能具有更大的开发潜能,有望代替野生滇龙胆以缓解其资源稀缺局面。本研究结果表明,采用傅里叶变换红外光谱法可以简便有效地对药用植物不同组培阶段不同组织部位的替代潜力及开发利用进行初步评估。     

Evaluation of the biological stability of waste during landfill stabilization by thermogravimetric analysis and Fourier transform infrared spectroscopy

This study seeks to assess the biological stability of landfilled municipal solid waste (MSW) based on the changes in organic matter, as revealed by thermogravimetric analysis and Fourier transform infrared (FTIR) spectroscopy. Derivate thermogravimetry profiles (DTG) showed a reduction in peak intensity at 200-350 °C (DTG2), while an increase in peak intensity and a shift towards higher temperature at 400-600 °C (DTG3). The decrease in the peak intensity of the aliphatic methylene at 2920 and 2850 cm(-1), and the increase of aromatic substances and polysaccharide at 1640 cm(-1) in the FTIR spectra also confirm the changes. Well-fitted correlations of the peak intensity ratio (2920/1640) and peak area ratio (DTG2/DTG3) to C/N ratio were also established, confirming that the 2920/1640 and the DTG2/DTG3 ratios can be considered as reliable parameters for tracking the biological stability of MSW during landfill stabilization.     

Effect of crown ethers on structure, stability, activity, and enantioselectivity of subtilisin Carlsberg in organic solvents.

Colyophilization or codrying of subtilisin Carlsberg with the crown ethers 18-crown-6, 15-crown-5, and 12-crown-4 substantially improved enzyme activity in THF, acetonitrile, and 1,4-dioxane in the transesterification reactions of N-acetyl-L-phenylalanine ethylester and 1-propanol and that of (+/-)-1-phenylethanol and vinylbutyrate. The acceleration of the initial rate, V(0), ranged from less than 10-fold to more than 100-fold. All crown ethers activated subtilisin substantially, which excludes a specific macrocyclic effect from being responsible. The secondary structure of subtilisin was studied by Fourier-transform infrared (FTIR) spectroscopy. 18-Crown-6 and 15-crown-5 led to a more nativelike structure of subtilisin in the organic solvents employed when compared with that of the dehydrated enzyme obtained from buffer alone. However, the high level of activation with 12-crown-4 where this effect was not observed excluded overall structural preservation from being the primary cause of the observed enzyme activation. The conformational mobility of subtilisin was investigated by performing thermal denaturation experiments in 1,4-dioxane. Although only a small effect of temperature on subtilisin structure was observed for the samples prepared with or without 12-crown-4, both 18-crown-6 and 15-crown-5 caused the enzyme to denature at quite low temperatures (38 degrees C and 56 degrees C, respectively). No relationship between this property and V(0) was evident, but increased conformational mobility of the protein decreased its storage stability. The possibility of a "molecular imprinting" effect was also tested by removing 18-crown-6 from the subtilisin-18-crown-6 colyophilizate by washing. V(0) was only halved as a result of this procedure, an effect insignificant compared with the ca. 80-fold rate enhancement observed prior to washing in THF. This suggests that molecular imprinting is likely the primary cause of subtilisin activation by crown ethers, as recently suggested.