A multipurpose, fast scan spectrophotometer for measuring turbid (biological) materials

A new optical spectrophotometer has been developed, based on a recently patented monochromator for spectral measurements of clear and, in particular, of turbid materials in the millisecond time range. The number of optical and mechanical components of the spectrophotometer has been reduced to a minimum, resulting in excellent light throughput, a low stray-light level, low cost, compactness and rigidity. The spectrophotometer has been designed for all kinds of spectral measurements such as absorption, transmission, reflection and luminescence/radiation in a single-beam mode as documented by several examples. In principle, there is no restriction of wavelengths, ranging from UV to NIR and up to the IR range. As many functions as possible are relocated from the hardware to the software part of the design, which allows for extraordinary flexibility and simplicity. An appropriate computer program providing data acquisition, control and calibration functions as well as real-time display of spectra has been developed on the basis of a compiler language; indispensable “fast routines” are written in assembler language.Presented at the joint meeting of the German Botanical Society and the German Zoological Society entitled: Spectroscopy and Optical Techniques in Animal and Plant Biology, Münster, 30th Sept-3rd October 1996     

雪松不同部位中原花青素的含量测定及其清除DPPH自由基的活性

雪松(Cedrus deodara)是松科(Pianaceae)雪松属(Cedrus)树种的泛称,为广泛分布于喜马拉雅山脉的常绿树种,包括雪松(C.deodara)、黎巴嫩雪松(C.libani)、短叶雪松(C.brevifolia)和北非雪松(C.atlantica)等。雪松的针叶药用历史悠久,主要化学成分为黄酮类、苯丙素类、有机酸类、三萜类、甾体类、多糖及针叶胶等,具有抗肿瘤、抗氧化、改善记忆、抗菌及抗病毒等多种功效。为了测定雪松不同部位中原花青素的含量,并考察其清除DPPH自由基活性的能力,该研究以Fe3+离子为催化剂,用正丁醇-盐酸法分别测定雪松松针、花序、小枝、木质部、树皮中原花青素的含量,并对不同部位提取液清除DPPH自由基的能力进行测定。结果表明:松针、花序、木质部、树皮、小枝中原花青素的含量分别为12.93%、12.93%、6.41%、12.00%、3.37%,在质量浓度(以生药计)为0.8 mg·m L-1时,其对DPPH自由基的清除率均达到或接近90%。该研究结果提示雪松各个部位的原花青素含量丰富,其提取液的体外抗氧化活性很高,这为雪松的进一步开发利用提供了很好的参考价值。     

In vitro anti-oxidant activity, fluorescence quenching study and structural features of carbohydrate polymers from Phyllanthus emblica

The water-extracted carbohydrate polymers (WE) of Phyllanthus emblica are analyzed using chemical, chromatographic, and spectroscopic methods. Anion-exchange-chromatography of WE yielded four fractions (F1-F4) with different chemical compositions and all of them contain phenolics. The major fraction F4 possesses 50% polysaccharide and 26% phenol, and is a glycoconjugate. The antioxidant capacities of WE and F4 are comparable to standard anti-oxidants. Notably, activities of F1-F4 correlate with their phenol content. Evidence for the complexation of F4 with bovine serum albumin is presented by fluorescence quenching measurement. The results also indicate conformational change of protein at high carbohydrate polymer concentration.     

黄喉鹀的羽色与雄鸟质量相关性分析

在国内首次利用光纤光谱仪对鸟类的羽色进行量化和分析.对黄喉鹀Emberiza elegans雌、雄鸟羽色的差异以及雄鸟羽色与雄鸟质量的相关性分析结果表明,黄喉鹀雌、雄鸟在人眼看来相同的黄色羽和白色羽部分,在紫外光色度上却存在显著差异,雄鸟紫外光色度高于雌鸟;雄鸟的质量与脸部黑色羽的亮度、可见光色度和色调呈显著正相关,雌...     

一些孟加拉当地产水果的抗氧化活性

研究了A.heterophyllus,A.squamosa,T.bellirica,S.samarangense,A.carambolaand O.europ水果的抗氧化活性。首先将这些成熟的水果切成小片,然后用日光晒干,最后用研磨器磨成粉末。这些水果粉末用99·99%的乙醇进行乙醇提取。这些提取物的活性通过其清除稳定的1,1-diphenyl-2-picrylhydrazyl(DPPH)自由基的能力进行测定。实验结果表明,所有A.heterophyllus,A.squamosa,T.bellirica,S.samarangense,A.carambolaand O.europa这些水果的乙醇提取物都具有抗氧化活性,这些水果的乙醇提取物的的IC50值分别是410,250,34,200,30和76μg/mL。其中A.carambola具有最高的抗氧化活性,其次是T.bellirica,O.europa,S.samarangense,A.squamosa和A.heterophyllus。结果表明A.carambola,T.bellirica和O.europa对人体健康是非常有益的。     

纳米级壳寡糖/DNA复合物的制备和性能研究

同甲壳素和壳聚糖这种生物大分子相比,壳寡糖具有许多独特的功能性质,如水溶性、保湿性、抗菌性、抗肿瘤和免疫促进性等。以数均分子量为5000的壳寡糖作为研究模型,根据凝胶电泳和紫外光谱分析,提出纳米级壳寡糖与pEGFPC-1质粒能通过静电结合或物理包裹形成复合物从而对DNA进行保护,同时证明形成壳寡糖/DNA复合物后,壳寡糖能够极大地提高DNA的贮存稳定性和结构稳定性;而DNaseI酶解实验也显示纳米级壳寡糖在合适比例下DNA有良好的保护作用,使其不被DNaseI降解,证明了纳米级壳寡糖应用于基因治疗载体的可行性与安全性。     

Demonstration of a highly-sensitive portable double-flash kinetic spectrophotometer for measurement of electron transfer reactions in intact plants

A highly sensitive, portable spectrophotometer for use in measuring flash-induced absorbance changes in intact leaves is demonstrated. The design of the instrument is modified for whole plant use from that suggested by Joliot and Joliot (Biochim. Biophys. Acta 765, 210–218). The spectrophotometer uses trifurcated light guides to deliver measuring and actinic beams to two comparable areas of the leaf. The measuring beam is provided by a series of short, relatively intense light pulses from a xenon flashlamp in place of the constant weak measuring beam used in conventional machines. The use of a flash measuring beam and differential detection allows for a high signal-to-noise ratio (noise levels of 10^-5A) without significant actinic effects. The time resolution of the instrument is 2 sec and the noise level is independent of the experimental time range. The instrument is battery or mains powered, computer operated, and has a liquid crystal display for computer-user interface and dialogue, and to show the kinetic traces graphically. Wavelength selection is provided by interchangeable interference filters. The instrument can communicate with a laboratory-based computer, receiving programming information and sending experimental data to be processed and plotted. The instrument is demonstrated by following the kinetics of the electrochromic shift, the change in redox states of cytochrome f and the b cytochromes in an intact cucumber leaf, and in the same leaf after infiltration with DCMU.     

黑斑蛙过氧化物酶活性测定条件的研究

本文报道了测定黑斑蛙过氧化物酶活力的两套方法.应用细胞组织化学的方法,对黑斑蛙的肝组织过氧化物酶的原位染色,以显示过氧化物酶在细胞中的分布.此外,还探讨了一种新的过氧化物酶活性检测方法,以联苯胺为底物,利用分光光度法测定反应液的吸光度,以吸光度的变化速率来表征过氧化物酶的活力.通过试验确定了该方法适宜的工作条件,包括酶浓度、温度、pH值等,得到酶活性变化的相关数据.     

分光光度法测定苦参中微量元素铜的含量

采用分光光度法测定了苦参中微量元素铜的含量,探讨了测定条件,并与火焰原子吸收光度法进行了对比。结果表明,两种方法的测定结果吻合,平均回收率分别为95.2%和101.6%,相对标准偏差分别为1.82%和1.10%,结果可靠,特别是分光光度法仪器价格低,操作简便,适用范围广,可用于实际样品的测定。