CHEMILUMINESCENCE IN THE PROCESS OF OXIDATIVE RING-OPENING OF PURPUROGALLINQUINONES

Abstract— The oxidation of purpurogalline (PPG) by alkaline solution of H₂O₂ pH 9–11 at 298°K is accompanied by chemiluminescence (CL) in the spectral range 400–600 nm with the maximum at 500 nm and quantum yield about 10^-6. The optimal concentrations of reactants with respect to maximal intensity are: 2 × 10^-4 M PPG, 10^-2 M NaOH, 1 M H₂O₂. Activation energy calculated from the maximum intensity of CL is 8.1×0.4 kcal/mole. Light emission occurs only when OH-groups of the phenolic ring of PPG undergo oxidation and the blue anion of o -PPG-quinone is formed. The rate that determines step in the reaction associated with luminescence is the nucleophilic attack of OOH^- ion on the blue anion of o -PPG-quinone. In this exergonic step (-ΔH = 63 to 230kcal/mole) the o - and/or p -quinone ring is opened and carbonyl derivatives of α-tropolone are produced. They display fluorescence in the region 400–600 nm. The fluorescence spectrum of the reaction mixture after oxidation of PPG is very close to that of CL. It is likely that carbonyl derivatives of α-tropolone are emitters of CL.     

CHEMILUMINESCENCE IN THE PHOTOOXIDATION OF HUMIC ACIDS*

Abstract— Photo-irradiation of aqueous basic solutions of soil humic acids and synthetic melanins with UV and visible light (Λ > 320 nm) under oxygen or nitrogen atmospheres generates electronic exicted states and radicals. These processes give rise to a long-lived chemiluminescence with emission maxima at 480–500, 570 and 615–650 nm, as well as a paramagnetic resonance (EPR) signal with g-value at 2.006 and ΔH～ 3Gs. Chemiluminescence intensity and EPR signals follow multistep kinetics. An increase of the ratio of OD at 260/400 nm and 400/600 nm and a decrease of amplitude of an EPR signal after prolonged photo-irradiation were observed. Long irradiation also causes a decrease of fluorescence intensity bands with maxima at 535 nm and 495 nm (Λ_ex 480 and 400 nm, respectively), and an increase of the short wavelength band with a maximum at 450 nm (Λ_ex 260 nm). The data indicate that a complex chain of reactions initiated by reactive species leads to the degradation of the aromatic core of the polymers. Oxygen efficiently enhances the chemiluminescence intensity and the rate of photodegradation. The mechanism of photodegradative oxidation and chemiluminescence probably involves an energy transfer process and singlet oxygen formation. The possibility of its occurrence in nature and its significance are discussed.     

FI-化学发光法测定吡哌酸

基于吡哌酸对Ce(Ⅳ) SO2-3化学发光体系有较强的增敏作用,结合流动注射分析技术,提出了吡哌酸的化学发光测定法。方法选择性好、灵敏度高。吡哌酸在1.0×10-7～1.0×10-5g·ml-1浓度范围内与化学发光分析信号呈线性关系,其检出限为4×10-8g·ml-1。对5.0×10-6g·ml-1的吡哌酸进行11次连续测定,相对标准偏差为2.5%。方法已成功地应用于片剂中吡哌酸含量的测定。     

THE CHEMILUMINESCENCE OF INDOLE DERIVATIVES IN DIMETHYL SULFOXIDE*

The chemiluminescent autoxidation of over fifty indoles has been measured in dimethyl sulfoxide (DMSO). The 3-alkylindole derivatives represent the brightest and most efficient members of this group. The chemiluminescence yield (per mole) of skatole is (1·5 ± 0·6) × 10^-3. The chemiluminescence spectrum of skatole is identical with the fluorescence spectrum of o-formamidoacetophenone in the same environment Similar results for 2,3-dimethylindole lead to the identification of the acylamide anion as the emitter in indole chemiluminescence. A peroxide ring cleavage excitation mechanism is proposed.     

CHEMILUMINESCENCE INDUCED BY OXIDATION OF TRYPTOPHAN BY SINGLET OXYGEN AND BY HYPOCHLOROUS ACID. IMPLICATIONS IN THE LUMINESCENCE EMITTED IN PHAGOCYTOSIS

Abstract— The mechanism of the chemiluminescence emitted during phagocytosis of opsonized zymosan was investigated. The use of an artificial system generating singlet oxygen permitted the distinction between the respective roles of O₂ and HOCl in the light production via the reactions with opsonized zymosan, amino-acids and peptides. The reaction of free hypochlorous acid, produced by the myeloperoxidase H₂ O₂-Cl- system, with free tryptophan appears to be a likely path for the production of chemiluminescence. Implications for the mechanism of in vivo chemiluminescence during phagocytosis are considered.     

PASSIVE AND ACTIVE ROLE OF FLUORESCERS IN THE CHEMILUMINESCENCE OF TETRAMETHOXYDIOXETANE

Abstract— Tests for the possible catalytic role of fluorescers in the chemiluminescent decomposition of dioxetanes are discussed and applied to the case of tetramethoxydioxetane. This dioxetane, which can undergo direct thermal decomposition yielding excited methyl carbonate with subsequent excitation of fluorescers (for example 9, 10-dibromoanthracene. DBA), is shown to be sensitive also to catalysis by fluorescers such as rubrene. 9, 10-diphenyl-anthracene (DPA) and 9, IOdicyanoanthracene (DCNA). The possibility of a charge-transfer mechanism of chemiluminescent catalysis is suggested.     

THE ROLE OF SUPEROXIDE AND SINGLET OXYGEN IN LIPID PEROXIDATION

Abstract— An investigation into the mechanism of lipid peroxidation catalyzed by xanthine oxidase showed a dependence upon superoxide, singlet oxygen and adenosine 5'-diphosphate chelated iron (ADP-Fe³⁺). In the absence of ADP-Fe³⁺ or in the presence of superoxide dismutase there is complete inhibition of enzymatic peroxidation. Initiation of peroxidation likely occurs through an ADP-perferryl ion complex formed by ADP-Fe³⁺ and superoxide. Use of the singlet oxygen trapping agent 2,5-diphenylfuran showed that singlet oxygen does not participate in the initiation of peroxidation but rather in the propagation of peroxidation. The mechanisms of NADPH-cytochrome P450 reductase-catalyzed and ADP-Fe²⁺ catalyzed lipid peroxidation parallel that of xanthine oxidase in that initiation occurs through a superoxide dismutase-sensitive reaction and that singlet oxygen is present during propagation of lipid peroxidation.     

THE QUANTUM YIELD OF THE CHEMILUMINESCENCE OF DIMETHYLBIACRIDYLIUM NITRATE AND THE MECHANISM OF ITS ENZYMICALLY INDUCED CHEMILUMINESCENCE*

Abstract— Quantum yields for dimethylbiacridylium ion chemiluminescence based on the amount of methyl acridone formed by treatment with either H₂O₂ or with xanthine oxidasehypoxanthine in 0.01 M Na₂CO₃ at pH 10.4 and at 25°C were found to lie between 0.011 and 0.020 with an average of about 0.016.In mixed solvents containing pyridine and water or alcohol and water the emission spectrum of chemiluminescence of dimethylbiacridylium ions as well as those of diniethylbiacridene and its oxide were found to be identical with or very similar to the fluorescence of methyl acridone in the same solvent.A mechanism involving two successive two equivalent reductions of the diniethylbiacridylium ion to dimethylbiacridan followed by a radical attack and auto-oxidation leading to a compound which can undergo a reverse aldol type reaction to yield one (or two) molecule of methylacridone and one of a somewhat more reduced form is suggested.The kinetic equation relating maximum intensity of chemiluminescence to dimethylbiacridylium ion, hypoxanthine, xanthine oxidase, H⁺ and O₂ concentrations was derived from the scheme suggested and found to fit satisfactorily the data obtained from a series of experiments in which the quantum yield was also obtained.     

氨基修饰超高交联树脂对单宁酸的吸附行为及机理研究

选用单宁酸作为天然有机酸中典型中分子、高水溶性有机酸,系统研究了氨基修饰超高交联树脂对单宁酸的吸附行为和机理.吸附等温线表明氨基修饰超高交联树脂WJN-08对单宁酸有较高的吸附容量,其静态饱和吸附量比传统商业吸附剂高15%以上;吸附表面分析表明离子键、π-π共轭作用和阳离子-π键是重要吸附作用力;吸附热力学试验表明树脂WJN-08吸附单宁酸是化学吸附主导,吸附焓变在20~22 kJ mol-1;吸附动力学试验表明树脂WJN-08吸附单宁酸速率同时受控于颗粒内扩散和膜扩散过程.动态小柱吸附-脱附实验表明树脂WJN-08对单宁酸有较好的吸附-脱附性能,饱和吸附量和穿透吸附量分别为24.43 mg g-1和19.56 mg g-1,脱附率为98.6%。     

CHEMILUMINESCENCE AND THE FORMATION OF SINGLET OXYGEN IN THE OXIDATION OF CERTAIN POLYPHENOLS AND QUINONES

Abstract— The possibility of ¹O₂ (¹Δ_g) participation in the oxidation of polyphenols and quinones has been investigated in two systems: (1) the system involving autooxidation leading to oxidative polymerization and destruction, and (2) the modified Trautz-Schorigin reaction, i.e. oxidation of polyphenols and HCHO with H₂O₂ in concentrated alkaline solutions. The red band with maximum at 635 nm observed in chemiluminescence of pyrocatechol, adrenaline, pyrogallol, gallic acid, adrenochrome and p -benzoquinone corresponds to the transition 2O₂(¹Δ_g) → 2O₂(³Σ^-_g). Emission bands in the range 475–540 nm arise from the superposition of the 2O₂(¹Δ_g) → 2O₂(³Σ^-_g) transition and radiative deactivation of excited oxidation products. In system (2) chemiluminescence has a broad band from 580 nm beyond 800 nm and much higher intensity than in system (1). Formaldehyde was found to enhance light emission in system (1) by a factor of about 30. The influence of solvents, including D₂O in which ¹O₂ has varying lifetimes, on kinetics of chemiluminescence as well as quenching effect of β-carotene, hydroquinone, cysteine, bilirubin and biliverdin strongly support the involvement of ¹O₂ in the chemiluminescence of both systems.     

THE CHEMILUMINESCENCE OF CERTAIN INDOLES*

Abstract— A series of twenty-four indoles and related compounds have been examined for chemiluminescent activity in aqueous solution and in dimethylsulfoxide. Seven compounds were found to chemiluminesce in the presence of base and peroxydisulfate in aqueous solution and eleven compounds gave chemiluminescence in dimethylsulfoxide with base using oxygen as the oxidizing agent. The relative intensities have been determined. There is no clear correlation between substitution patterns and the presence of chemiluminescence in either series. Some preliminary kinetic studies have been made on the indole system. Product studies indicate that the indole is degraded by at least two different pathways and that chemiluminescent process is probably only a small fraction of the total chemical change occurring.     

EFFECT OF IRON(III) ON CHEMILUMINESCENCE FROM THE NEUTRALIZATION REACTION OF NITRIC ACID and POTASSIUM HYDROXIDE

Low levels (around 90 μM) of iron(III) caused an increase in chemiluminescence (CL) from the neutralization reaction involving nitric acid and potassium hydroxide without use of any luminescent reagent. When oxygen was excluded from the reaction, a significant decrease in the CL emission was observed. This suggests that molecular oxygen present in the solutions may play an important role in the process of the iron-catalyzed CL induced by the neutralization reaction, which liberates a sufficient energy. Other experimental parameters like the influence of several other metal ions, counteranions and acid media were also examined. The results showed that the observed CL enhancement by iron(III) proved to become most remarkable under sporadical conditions alone, and the presence of small amounts (less than 0.20 mM) of sulfate ion increase the catalytic activity of iron(III). A possible mechanism involving transient formation of iron–radical complexes upon neutralization and subsequent reaction of the complexes with molecular oxygen is considered for the present CL reaction.     

STUDIES ON THE CHEMILUMINESCENCE OF LUMINOL IN DIMETHYLSULFOXIDE AND DIMETHYLSULFOXIDE-WATER MIXTURES*

Abstract— The absorption, fluorescence, and chemiluminescence (CL) characteristics of luminol have been studied in basic dimethylsulfoxide (DMSO) and various basic DMSO — water mixed solvents. It has been shown that the luminol dianion can be produced quantitatively in carefully deoxygenated ‘dry’ DMSO using potassium t-butyl alcoholate (BTO) as the base. A direct correlation has been found between the intensity of CL and the concentration of luminol dianion, Indicating that the dianion is the reactive species in the chemiluminescent reaction in DMSO. Increasing concentrations of water in the mixed solvents greatly reduced the CL intensity because of the decrease in luminol dianion concentration. Solvent effects on the fluorescence of 3-aminophthalic acid samples was noted and identified. Chemiluminescent spectra of luminol were run as a function of solvent composition, and compared with fluorescence spectra in the same media. The need for correcting these spectra for comparison was noted. Stopped flow kinetic studies were run in DMSO and DMSO-water mixtures. These data can be interpreted on the basis of two second-order steps and one first-order step in the reaction. The first-order step is probably last and probably arises from decomposition of a ‘peroxy’ intermediate. The rate constant for this step is k= 1·2±0·3×10^-1 sec^-1.     

偶合发光法测定熟肉制品中亚硝酸盐的含量

用亚硝酸盐把亚铁氰化钾氧化为铁氰化钾后,与鲁米诺、尿酸组成化学发光体系,建立了一种间接测定痕量亚硝酸盐的方法。探讨了酸度、反应物浓度、干扰离子等因素的影响。该方法的检出限为5.0×10~(11)g/mL,线性范围为1.0×10~(-9)～1.0×10~(-5)g/mL。对熟肉制品样品进行11次平行测定,回收率为92.8％～107.6％,测定结果的相对标准偏差为2.2％～3.9％。     

OXIDATION OF INDOLE-3-ACETIC ACID BY SONICATED NEUTROPHILS. PITFALLS IN CORRELATING EPR SIGNALS AND CHEMILUMINESCENCE

Abstract –The oxidation-peroxidation of indole-3-acetic acid by sonicated neutrophils, unlike the horseradish peroxidase-catalyzed process, features not only the skatole radical, but also a tertiary carbon-centered radical in the electron paramagnetic resonance (EPR) spectrum. Moreover, emission occurs only in the red.
From the present and earlier data it is concluded that the observation of the skatole radical does not necessarily indicate its involvement in the ¹Δ_gO₂ generating process. Also unlikely is a correlation between the tertiary carbon-centered radical and red emission.
Our results indicate that in general great care must be taken in attempting to correlate EPR signals with chemi-luminescence and with oxygen consumption.     

食品中苯甲酸、山梨酸含量测量不确定度的评估

对按照SN 04024—87方法测定食品中苯甲酸、山梨酸含量的测量不确定度进行评估。该测量方法为相对测量法，前处理等过程直接用B类评定比较困难，直接以多次重复测量数据为依据，即以A娄评定为主、B类评定为辅的方法，结果更为客观、准确，完全适合实际操作。     

PEROXIDASE INDUCED CHEMILUMINESCENCE IN THE OXIDATION OF PYROGALLOL AND PURPUROGALLIN. INFLUENCE OF AZIDE

Abstract— The chemiluminescence (CL) emitted during the peroxidase catalyzed oxidation of purpurogallin and pyrogallol depends on one and two molecules of enzyme, respectively. Using microperoxidase, CL with purpurogallin also depends on two molecules of enzyme (above 0.3 μ M enzyme). Sodium azide inhibits the CL emitted by all reactions depending on two molecules of enzyme but enhances the CL of reactions depending on one molecule of peroxidase (purpurogallin + 0.75 n M horseradish peroxidase). The formation of functional enzyme dimols during the oxidative process is discussed.     

聚乙烯醇／明胶复合型吸附树脂的合成及其对鞣酸的吸附性能

用反相悬浮聚合法合成了聚乙烯醇／明胶复合型吸附树脂,研究了该类树脂对鞣酸的吸附性能。结果表明,树脂中聚乙烯醇组分的引入,能有效地阻止明胶链之间氢键的形成,使树脂能通过氢键作用选择性吸附鞣质。模拟的应用实验说明,这类吸附树脂可用于某些中药剂型,如口服液,针剂生产中有害及不稳定成分鞣质的选择性去除。     

CHEMILUMINESCENCE FROM THE OXIDATION OF AUXIN DERIVATIVES

Abstract— The thiophenyl ester of indole-3-acetic acid and indole-3-acetonitrile produce chemiluminescence in aerated dimethylsulfoxide in the presence of potassium t -butoxide. The emitter is the aromatic aldehyde. In the case of acetonitrile, the other product expected from the cleavage of an intermediate dioxetane, cyanate/isocyanate, has also been identified. Other auxins also chemiluminesce under similar conditions, but the emitters have not been properly identified.
These systems are models for the peroxidase catalyzed oxidation of indole-3-acetic acid to indole-3-carboxaldehyde and as such support the earlier inference (Vidigal et al , 1975) that the excited aldehyde is generated in the enzymic process.
An additional result is the observation of an exciplex between excited indole-3-carboxaldehyde and the thiophenylester of indole-3-acetic acid. This appears to be the first case of chemical generation of an exciplex by a route other than radical ion reaction, presumably by the dioxetane route.