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1.
以(R)-( )-香茅醇为原料,经溴化甲氧基化、消除、酸诱导环合三步反应合成了氧化玫瑰,三步总收率为75.6%。所得氧化玫瑰顺反异构体比例为70/30-75/25,可用于配制高级玫瑰香精。  相似文献   

2.
沙晋康  蔡琮莹 《有机化学》1993,13(2):162-165
叠氮基-丙二酸烷叉酯的分子内1,3-二极环加成和环翻转反应被用于制备异缩合杂环芳香吡咯的新方法, 报导了这一方法用于合成2,4-二氢吡咯[3,4-b]吲哚环系, 同样这一环系被用于椭园玫瑰树碱的全合成。  相似文献   

3.
玫瑰花具有重要的观赏和药用价值, 主要的化学成分有玫瑰精油、黄酮类、多糖类和酚酸类等, 具有心肌保护、抗氧化、抑菌、抗肿瘤、抗病毒、镇静催眠作用、调节血脂和降血糖等生物活性.玫瑰精油是高级香水、香料和化妆品不可取代的原料, 其提取工艺是工业研究的重点.对玫瑰花中的化学成分和生物活性进行了综述, 并重点总结了玫瑰精油的提取工艺、成分和生物活性, 为玫瑰花, 特别是玫瑰精油的研究和开发提供参考.  相似文献   

4.
用微波消解-火焰原子吸收光谱法测定了玫瑰枝条和叶片中5种微量元素元素(钙、铜、铁、锰、镁)的含量.结果表明,玫瑰枝条和叶片中含有较丰富的镁、钙、铁,铜、锰含量较低,该法灵敏度高、快速、准确,所测数据可为玫瑰枝叶的合理利用提供可靠依据.  相似文献   

5.
用微波消解一火焰原子吸收光谱法测定了玫瑰枝条和叶片中5种微量元素元素(钙、铜、铁、锰、镁)的含量。结果表明,玫瑰枝条和叶片中含有较丰富的镁、钙、铁,铜、锰含量较低,该法灵敏度高、快速、准确,所测数据可为玫瑰枝叶的合理利用提供可靠依据。  相似文献   

6.
羰基化反应生成酯类的研究进展   总被引:1,自引:1,他引:1  
吕士杰  刘全杰 《分子催化》1998,12(5):392-400
羧酸酯类是重要的化工产品.由于酯类化合物大都具有鲜花或水果型如丁香、玫瑰、茉莉、香蕉、菠萝、草莓等的香味而大量用于酒类、糕点食品、香皂、化妆品工业.高碳羧酸酯则用于做定香剂.酯类的传统制法是用羧酸、羧酸酐或酰氯与醇反应生成.某些酸较缺乏,酰氯价格也较...  相似文献   

7.
王伟峰  张瑛  杨军丽 《色谱》2020,38(10):1232-1237
玫瑰纯露是玫瑰提取精油后的重要副产物,是玫瑰精油的饱和水溶液,不仅含有植物水溶活性成分,同时也保留了精油的芳香成分,含有矿物养分,具有抗衰老、清除自由基,抗过敏、抗菌、消炎、防紫外线损伤等功效,是继玫瑰精油之后护肤领域重要的优势产品之一,但目前尚无关于其质量控制的标准,市售产品质量参差不齐。为此,该研究发展了一种胶束电动毛细管色谱法用于快速检测玫瑰纯露中的指标成分苯乙醇。在实验过程中分析物的定性通过标准物质加标及紫外吸收可见光谱图比对确认。实验对缓冲溶液中硼砂浓度、十二烷基硫酸钠(SDS)浓度、分离电压、进样条件、检测条件等影响检测的关键因素进行了考察。在优化条件(分离缓冲溶液10 mmol/L Na2 B2 O7 +15 mmol/L SDS,分离电压+20 kV,检测波长208 nm,进样5 kPa,5 s)下,玫瑰纯露样品在7 min内可以完成检测。本方法对苯乙醇检测的线性范围为0.50~1000 mg/L,线性相关系数(r 2 )为0.9990,检出限(LOD,S/N =3)为0.091 mg/L,定量限(LOQ,S/N =10)为0.35 mg/L,实际样品加标回收率为98.1%~102.7%(加标水平10、100、500 g/L),相对标准偏差(RSD)≤2.8%。结果表明,该方法为玫瑰纯露及其制品的质量控制提供了一种简便、快速、灵敏、稳定的分析方法。  相似文献   

8.
研究了利血平与玫瑰精B的显色反应,建立了测定利血平的高灵敏分光光度法。在酸性条件下,利血平的水解产物和玫瑰精B形成具有正、负吸收峰的红色离子缔合物,最大正吸收波长位于490 nm,最大负吸收波长位于520 nm,表观摩尔吸光系数(ε)分别为1.20×105L.mol-1.cm-1(正吸收)和1.83×105L.mol-1.cm-1(负吸收),利血平在0~5.0μg/mL范围内遵从比尔定律。若采用正、负峰叠加测定,灵敏度可达3.00×105L.mol-1.cm-1。探讨了适宜的反应条件、主要分析特性及方法的精密度和可靠性。该法可用于市售利血平注射液中利血平含量的测定。  相似文献   

9.
建立了毛细管电泳-激光诱导荧光法同时测定红枣中的罗丹明6G、藏红T、孟加拉玫瑰红和荧光桃红B四种工业染料的方法。对电泳介质的种类、浓度、p H值及分离电压和进样量等因素进行了优化。在0.01 mol·L-1硼砂-30%乙腈(p H=9.5)条件下,可在8 min内实现罗丹明6G、藏红T、孟加拉玫瑰红和荧光桃红B的分离检测。线性范围分别为7.2~407.2、70.2~350.8、101.8~1017.6和41.5~705.2 ng·m L-1,检出限分别为3.7、38.2、64.4和20.9 ng·m L-1,回收率分别为101.8%、98.3%、97.7%和103.0%。可用于红枣中四种工业染料的分离检测。  相似文献   

10.
蔡岩  苗志伟 《化学通报》2021,84(10):1108-1113,1119
玫瑰红景天具有上千年的药用历史,是我国传统中药中的瑰宝。大量研究表明,玫瑰红景天提取物对人体中枢神经系统、心血管系统以及内分泌系统具有保护和调节作用,尤其在抗疲劳、抗抑郁、抗肿瘤及提高人体免疫力等方面具有独特的药效。本文介绍了玫瑰红景天的药用开发历史及其特征活性成分的功能,以期提高人们对这种传统中药的认识,为进一步开发玫瑰红景天的药用功能提供借鉴和参考。  相似文献   

11.
pH异常变化与癌症和神经退行性等各种疾病相关,监测p H的变化对研究病理状况至关重要。本文设计合成了一种新型的p H荧光探针MC-p H。该探针最大发射波长在近红外区,可有效避免生物样品自身荧光。探针MC-p H中亚胺基团的质子化与非质子化是荧光开关的关键。在酸性溶液中,MC-p H以亚胺离子形式存在,最大吸收波长为617 nm,最大荧光发射波长为663 nm。随着p H逐渐升高,探针MC-p H主要以亚胺形式存在,617 nm处的特征吸收峰强度逐渐降低,并在467 nm处出现新的吸收峰,且663 nm处的荧光强度急剧降低直至消失。探针MC-p H可以监测溶液中p H的变化,线性范围为p H 3.0~8.0,不受其他常见干扰物的影响,且具有良好的细胞渗透性,可监测He La细胞内p H的变化。  相似文献   

12.
The influence of nutrient level, hours of fight and the flux of air by volume of solution on uptake of lead has been examined from batch growth experiments carried out with the alga Selenastrum capricornutum Printz. The organic matter released by the alga has been characterized in terms of absorbance at 285 nm, dissolved organic carbon and maximum intensity of fluorescence at the excitation peak. The lability of lead complexes formed with the alga exudates has been investigated in terms of differential pulse anodic stripping voltammetry (DPASV). It has been noticed that lead inhibits the division of the cells which become bigger in size but with less pigment per cell.  相似文献   

13.
We report the preparation of the methanolic extract (ME), and polar methanolic fraction (PMF) from the plant Hypericum perforatum L. The extracts contain various photosensitizing constituents such as naphthodianthrone derivatives (in 1.37% w/w), and chlorophylls (in 0.08% w/w). Upon light emission these constituents can be activated, providing photodynamic properties to the extracts, and making them a potent, new class, natural photosensitizers for use in photodynamic therapy (PDT), and photodynamic diagnosis (PDD). The absorbance spectra of the extracts are similar to the spectrum of hypericin, the main naphthodianthrone identified within, with two major bands at 548 and 590 nm. The fluorescence spectra in ethanol exhibit two main bands around 595 and 640 nm, in accordance with the spectrum of pure hypericin. The fluorescence intensity of PMF at 595 nm is only eight times less than the intensity of pure hypericin at the same wavelength, even though its hypericin concentration is only 0.57% w/w. The dependence of the PMF fluorescence signal on the pH of the medium, alone and in comparison with the signal of hypericin, has been investigated. PMF signal fades steadily, and smoothly both in acidic, and basic environment.  相似文献   

14.
铝试剂的荧光光谱与荧光量子产率   总被引:4,自引:0,他引:4  
首次研究了铝试剂的荧光光谱和荧光量子产率,发现pH3至pH12条件下,用紫外光照射铝试剂溶液可以产生荧光,最大激发波长和最大发射波长分别为297nm和409nm,荧光强度与铝试剂浓度之间存在良好的线性关系,线性范围为0.01~3μg/mL,检测下限为0.01μg/mL,以硫酸奎宁为参比,测得铝试剂的荧光量子产率为0.16。  相似文献   

15.
在pH 9.3的氨-氯化铵缓冲溶液中,铽(Ⅲ)能与依诺沙星、十二烷基硫酸钠(SDS)形成荧光配合物(λex=330 nm、λem=545 nm),SDS的存在能增强配合物的荧光强度。研究发现,在该反应体系中加入适量雷公藤红素溶液后,铽(Ⅲ)与依诺沙星络合物的激发、发射峰位置不变,但其荧光强度呈规律性下降。据此,建立了简单、快速、灵敏地测定雷公藤红素的荧光分析方法。雷公藤红素的浓度在5.2×10-6~8.4×10-5 mol/L范围内呈良好线性关系,方法的检出限为4.1×10-8 mol/L。  相似文献   

16.
In this paper, a new dual fluorescent N,N-dimethylaminonaphthalene derivative, sodium 4-(N,N-dimethylamino)naphthalene-1-sulfonate (SDMDNS), was reported. It was found that SDMDNS emits dual fluorescence only in highly polar solvent water but not in organic solvents such as methanol, dioxane and acetonitrile. Only a single broad band emission at ca. 420 nm was observed in the short wavelength region in organic solvents. The dual fluorescence of SDMDNS in water was found at 423 and 520 nm, respectively. Introduction of organic solvent as ethanol into aqueous solution of SDMDNS leads to blue shift of the long-wavelength emission, and this was evidently supported by introduction of cyclodextrin or surfactant in the aqueous solution. It indicates that a highly polar solvent was required to bring out dual fluorescence; furthermore, the short wavelength fluorescence is emitted from locally excited (LE) state and the long wavelength fluorescence is emitted from charge transfer (CT) state. The pH dependence of the dual fluorescence of SDMDNS demonstrates that the neutral form of the molecular has a higher ratio of CT band intensity to LE band. Temperature effect on the excited state of SDMDNS was also examined and gave stabilization enthalpy (-DeltaH ) of the CT reaction 8.7 kJ mol(-1).  相似文献   

17.
Huitink GM  Poe DP  Diehl H 《Talanta》1974,21(12):1221-1229
A satisfactory method for the preparation of Calcein Blue has been devised. Elemental analysis, equivalent weight by neutralization, and the NMR spectrum show the compound to be 4-methylumbelliferone-8-methyleneiminodiacetic acid·0·25H2O. The ultraviolet absorbance and fluorescence have been studied as a function of pH and, combined with potentiometric titration and solubility date, have yielded for the acid dissociation constants the values pK1 = 3·0, pK2 = 6·9, and pK3 = 11·3. These acid functions are identified respectively as carboxyl, phenol, and ammonium ion, the free Calcein Blue being a zwitter-ion. Calcein Blue fluoresces in both acidic and basic solution when excited at a suitable wavelength. The fluorescence of the doubly-charged anion formed on the neutralization of the phenol group, when excited at 360 nm, reaches a maximum at pH 9, and decreases to zero with the neutralization of the ammonium ion; the wavelength of maximum emission is 455 nm. In the presence of calcium, the fluorescence increases with alkalinity up to pH 9 and then remains constant. The calcium derivative is a 1:1 compound, formation constant 107·1. The fluorescence of Calcein Blue at all pH values is quenched by copper(II). The calcium derivative is changed on standing in highly alkaline solution, presumably by ring opening, to another fluorescent material; thus Calcein Blue, although satisfactory as an indicator, is not useful for the direct fluorometric determination of calcium.  相似文献   

18.
人血清蛋白-丙酮(乙醇)体系的荧光光谱及共振散射光谱特性  相似文献   

19.
Yang  Yao  Zhang  Shengrui 《分析试验室》2022,(9):1021-1024
Yellow-green fluorescent carbon dotsY-G-CDswas used as a fluorescent/colorimetric dual-mode nanoprobe for the detection of pH value in solution and fluorescent painting. The fluorescent intensity and absorbance of the nanoprobe showed strong pH dependence. The fluorescent intensity at 520 nm and the ratio of absorbance at 438 and 386 nm showed good linear relationships with the pH valuein the ranges of pH 5.9-7.7 and pH 5.9-8.0respectively. As a fluorescent nanoprobeY-G-CDs had good photo stability at pH 5.96.8 and 8.0and good reversibility between pH 5.9 and pH 7.7. The detection of pH value of solution was not affected by other interfering substances. In additionthe Y-G-CDs with excellent fluorescent performance have been successfully applied in fluorescent painting as a fluorescent ink. Under the irradiation of 365 nm UV lightthe drawing image emitted bright green fluorescence with clear outline. © 2022, Youke Publishing Co.,Ltd. All rights reserved.  相似文献   

20.
Diehl H  Horchak-Morris N 《Talanta》1987,34(8):739-741
The ultraviolet absorption spectum of an aqueous solution of highly-purified yellow fluorescein at ionic strength 0.10 has been measured at various pH values in the range from 0.15 to 8.70. The maxima at 227, 249 and 295 nm change little with pH, but the maximum found at 437 nm in acid medium changes greatly in absorbance and position on addition of alkali, resolving first into two maxima, at 455 and 475 nm, and finally becoming a single large maximum (at pH 8) at 490 nm. A unique feature of the absorption at 437 nm is that all four prototropic forms of fluorescein, H(3)Fl(+), H(2)Fl, HFl(-) and Fl(2-), absorb at this wavelength. The total absorbance at this wavelength first falls rapidly as the pH rises from 0.15, reaching a minimum at pH 3.63, then increases to a maximum at pH 5.3, and finally falls to steady value at pH > 8.0. The absorbance as a function of pH is defined by seven constants: three dissociation constants (K(H(3)Fl) = 6.61 x 10(-3), K(H(2)Fl) = 3.98 x 10(-5), K(HFl) = 4.36 x 10(-10)) and four molar absorptivities ((H(3)Fl) = 4.94 x 10(-4), (H(2)Fl) = 1.20(5) x 10(4), (HFl) = 2.16 x 10(4) and (Fl) = 7.61 x 10(3) 1.mole(-1).cm(-1)). Solutions of yellow fluorescein in water undergo rapid deterioration on exposure to daylight or fluorescent lighting but are stable in the dark.  相似文献   

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