A facile synthesis of 4-hydroxy-2(E)-nonenal

A facile, efficient synthesis of 4-hydroxy-2(E)-nonenal is presented as an alternative to the approaches published previously, which either employed four to six separate steps or furnished low yields. The commercially available 3(Z)-nonenol was sequentially oxidized into 3,4-epoxynonanol by 3-chloroperoxybenzoic acid followed by oxidation of the alcohol by periodinane to afford 4-hydroxy-2(E)-nonenal by this two-step procedure in 48±7% yield.     

Convenient and efficient syntheses of 4-hydroxy-2(E)-nonenal and 4-oxo-2(E)-nonenal

Lipid peroxidation products 4-hydroxy-2(E)-nonenal (HNE) and 4-oxo-2(E)-nonenal (ONE) were conveniently synthesized using Wittig and Horner-Wardsworth-Emmons (HWE) reaction. Wittig or HWE reaction between an easily prepared phosphorane or phosphonate with glyoxal dimethyl acetal gave a protected 4-oxo-2(E)-nonenal. Hydrolysis gave 4-oxo-2(E)-nonenal, whereas reduction followed by hydrolysis gave 4-hydroxy-2(E)-nonenal.     

Effect of 4-hydroxy-2(E)-nonenal on soybean lipoxygenase-1

The oxidation of linoleic acid by soybean lipoxygenase-1 (LOX-1) was inhibited in a time-dependent manner by 4-hydroxy-2-(E)-nonenal (HNE). Kinetic analysis indicated the effect was due to slow-binding inhibition conforming to an affinity labeling mechanism-based inhibition. After 25 min of preincubation of LOX-1 with and without HNE, Lineweaver-Burk reciprocal plots indicated mixed noncompetitive/competitive inhibition. Low concentrations of HNE influenced the electron paramagnetic resonance (EPR) signal of 13(S)-hydroperoxy-9(Z), 11(E)-octadecadienoic acid (13-HPODE)-generated Fe³⁺-LOX-1 slightly, but higher concentrations completely eliminated the EPR signal indicating an active site hindered from access by 13-HPODE. HNE may compete for the active site of LOX-1 because its precursor, 4-hydroperoxy-(2E)-nonenal, is a product of LOX-1 oxidation of (3Z)-nonenal. Also, it was an attractive hypothesis to suggest that HNE may disrupt the active site by forming a Michael adduct with one or more of the three histidines that ligate the iron active site of LOX-1.     

Method for analysis of 4-hydroxy-2-(E)-nonenal with solid-phase microextraction

A simple analytical method for 4-hydroxy-2-(E)-nonenal (HNE) using solid-phase microextraction (SPME) fiber was developed. HNE or the derivative of HNE formed by reaction with 2,4-dinitrophenylhydrazine (DNPH) was extracted from the sample solution by immersing the SPME fiber into the solution, and the amount of HNE was quantified by HPLC. The extraction conditions of HNE and HNE-DNPH were examined, using standard solutions, with respect to fiber coating, NaCl concentration, rate of stirring, adsorption temperature, and adsorption time. The recovery of HNE reached 80%, and the quantification limits of HNE and HNE-DNPH using standard compounds were 14.1 pmol/10 mL and 486.5 fmol/10 mL, respectively. This method can be applied to the detection of HNE in oxidized oil or samples of porcine liver.     

Nickel extraction by 2-hydroxy-5-tert-butylbenzaldehyde oxime

Nickel extraction from aqueous solutions between pH 3 and 10 using 2-hydroxy-5-t-butylbenzaldehyde oxime was investigated. Iso-octane, octane, xylene and dichloro-ethane were used as diluents. It was found that nickel extraction is dependent upon the equilibrium pH, the mol ratio of oxime : nickel and the nature of the diluent. The composition of the nickel-oxime complex is in the ratio of 1:2. Extraction data, infrared spectra and cryoscopic measurements have shown the association of the oxime in the organic phase and the solvation of the nickel complex by the oxime molecules. The degree of solvation was found to be higher in dichloroethane than in octane.     

萃取剂2-羟基-5-壬基苯乙酮肟的合成

本文以4-壬基酚、乙酰氯、无水AlCl3和盐酸羟胺为主要原料合成了2-羟基-5-壬基苯乙酮肟（HNAO）。合成2-羟基-5-壬基苯乙酮（HNA）时，采用了-步法，以四氯乙烯为溶剂，n（4-壬基酚）：n（乙酰氯）：n（AlCl3）=1：2：1．2，加毕AlCl3后补加4-壬基酚物质量0．2倍的乙酰氯，回流温度下（120℃）反应6h。HNA收率为98．1％，纯度为79．5％。合成HNAO时，以蒸馏的HNA为原料，以甲苯为溶剂，导辛酸钠为相转移催化剂，n（HNA）：n（盐酸羟安）：n（碳酸钠）=1：1．3：0．85，75℃下反应4．5h。HNAO收率为97．9％，纯度为88．6％。FT—IR分析结果表明所得中间体及产物与HNA和HNAO特征相符。     

2-(2'-羟基-5'-异丙烯酸乙酯基苯基)-2H-苯并三唑的合成

以邻硝基苯胺和对羟基苯乙醇为原料,经过重氮化、偶合、还原和酯化合成了适合于工业化生产的2-(2′-羟基-5′-异丙烯酸乙酯基苯基)-2H-苯并三唑,其结构经核磁共振确证。     

2-羟基-4-甲氧基-5-磺酸基二苯甲酮的合成

采用间苯二甲醚为原料,经酰化、脱甲基、磺化一系列的反应合成2-羟基-4-甲氧基-5-磺酸基二苯甲酮,并对其物料配比、催化剂用量、反应温度以及反应时间等因素作了探索.结果表明酰化反应较佳条件为:以二氯甲烷为溶剂,n(间苯二甲醚)∶n(苯甲酰氯)∶n(无水AlCl3)=1∶1.05∶1.05,反应温度0～5℃,反应时间3 ...     

Differential toxicity of juglone (5-hydroxy-1,4-naphthoquinone) and related naphthoquinones to saturniid moths

The preferred hosts of the saturniid mothActias luna include members of the Juglandaceae, whose foliage contain the toxin juglone (5-hydroxy-1,4-naphthoquinone). The performance ofActias luna andCallosamia promethea was compared when fourth-instar larvae of each were fed birch foliage, a mutually acceptable food plant, or birth supplemented with 0.05% (w/w) juglone.A. luna fed juglone exhibited no changes in developmental time or mortality compared to a diet without juglone. In contrast, juglone-supplemented diets, when fed toC. promethea, caused negative growth rate, and a 3.6-fold decrease in consumption rate. The performance ofA. luna also was compared on birch and walnut; larvae developed and grew more rapidly on an all-walnut vs. an all-birch diet. To examine the effect of 1,4-naphthoquinone structure onA. luna survival, first instars were fed on birch supplemented with varying concentrations of juglone (J), menadione (M), plumbagin (P), or lawsone (L). In diets supplemented at 0.05% (w/w), none of the compounds produced effects significantly different from controls. In diets supplemented at 0.5% (w/w), the treatments produced significant toxic effects in the order P>M=L>J for mortality, and P>L>M=J for increased developmental time. Late-instarA. luna are clearly resistant to juglone compared toC. promethea, and early-instarA. luna are resistant to several related 1,4-naphthoquinones. These results suggest a chemical basis for host choice among saturniids. In addition, the luna-walnut system may be a valuable model for studying quinone detoxication.     

3—甲氧基—5—甲基水杨醛合成的新方法

一种较为理想的３－甲氧基－５－水杨醛的合成方法。以２－甲氧基－４－甲基苯酚为起始原料，酚羧基甲氧基甲醚化后，使苯环被选择性地锂化，然后在苯环的甲氧甲氧基邻位引入醛基。相应化合物的熔点和＾１ＨＮＭＲ化学位移。