小分子螺吡喃光致变色化合物合成研究进展

螺吡喃是一类研究较为广泛的有机光致变色化合物,在光信息记录与存储、分子开关、军事伪装等领域有着巨大的应用潜力。本文以关注小分子螺吡喃化合物的合成路线为目的,综述了螺吡喃、螺硫代吡喃、螺硒代吡喃的合成方法,介绍了超声波、微波技术在螺吡喃化合物合成中的应用,指出了小分子螺吡喃类化合物合成领域尚待加强的几个研究方向。     

卟啉化合物的合成方法综述

由于卟啉及其金属化合物在生物化学、医学领域、分析化学、合成化学、材料科学等领域中的应用都有了迅速的发展。所以对卟啉类化合物的研究具有重要意义。本文详细的介绍了卟啉卟啉化合物的合成方法。     

卟啉化合物的应用与合成研究进展

卟啉化学是现代化学领域中重要的研究分支之一。概述卟啉化合物在医学、化学、生物学、材料学、能源等领域的应用;同时还介绍了卟啉化合物的合成方法。     

3-氟-4-碘二苯醚的合成

标题化合物是合成觉醒促进剂、Lp-LPA2抑制剂、酪氨酸激酶抑制剂等药物的重要中间体。因此,在医药领域有着重要的地位。虽然,标题化合物在医药领域应用较为广泛,但化合物的合成工艺未见文献报道。通过大量的实验研究与工艺优化,最终形成了以4-溴-2-氟苯胺为原料,经保护、成醚、脱保护和Sandmeyer反应得到目标化合物的最佳工艺条件。该合成路线具有原料简单易得、合成条件安全易操作、产率较高的优点,总收率为87%,适合工业化生产,为其工业化合成降低成本,也为该化合物的研究与发展提供了推动作用。     

卟啉化合物的合成与应用研究进展

卟啉化学是现代化学领域中重要的研究分支之一,文章综述了卟啉化合物的合成方法,以及卟啉化合物在生物医学、材料科学及催化化学等领域的应用.     

金属卟啉化合物合成研究初探简

金属卟啉化学是现代化学研究的热点领域之一.本文简述了金属卟啉化合物的结构和性质,对“两步法”合成金属卟啉进行了探究,即先用经典Adler法合成卟啉母体化合物,然后再采用液相法或固相法合成金属卟啉化合物.     

腙类化合物的合成及应用研究

腙类化合物在药物、农药等领域发挥着越来越重要的作用,其合成方法也日益受到重视。本文对近年来腙类化合物的合成方法研究进展进行了分类归纳总结,着重展示了肼、重氮化合物以及含氮杂环化合物在腙合成中的应用。     

酶法合成精细化学品与药物

酶促催化合成精细化学品及药物是有机合成在化学领域的一个重大进展,酶法合成在手性化合物、药物、功能生物分子、非天然化合物、精细化学品及其中间体等方面具有明显的优势和应用前景。     

基于卟啉的药物活性化合物的合成研究进展

综述了十几年来基于卟啉的药物活性物质的设计思路和合成方法,重点介绍了基于卟啉的光敏剂及二元活性化合物的合成.同时,展望了卟啉类药物活性化合物合成领域的未来发展趋势.     

芳基异硫氰酸酯的合成与应用

芳基异硫氰酸酯是一类应用极为广泛的有机中间体和重要试剂,用于合成多种含氮、含硫、或含氧等杂环化合物,广泛应用于农药、医药和精细化工等领域。其合成方法及应用受到化学家的广泛重视。文章综述了芳基异硫氰酸酯的多种合成方法及其在化合物合成、医药方面的应用。     

异硫氰酸酯的制备及应用

本文综述了异硫氰酸酯的实验室制备方法,并介绍了其在杂环化合物合成及生物技术等方面的应用。     

Isothiocyanates from enzymatic hydrolysis ofLesquerella seed meals

Enzymatic hydrolyzates from seed meals of 17 species of the genusLesquerella, family Cruciferae, were examined for thiooxazolidones and volatile isothiocyanates. Quantitative estimates of the total volatile isothiocyanates, calculated as butenyl, ranged from 0.6 to 13.0 mg per g of solvent-extracted meal. No thiooxazolidone was found. By means of paper chromatography, melting point, and X-ray patterns of the thiourea derivatives, the volatile isothiocyanates, 3-methylthiopropyl-, 4-methylthiobutyl-, and 6-methylthiohexyl-, were shown to be present in the hydrolyzates from three species. Evidence for identity of isothiocyanates in hydrolyzates from the remaining species was obtained by paper chromatography of the thiourea derivatives. Presented in part to the American Chemical Society, Chicago, Ill., September 3–8, 1961. A laboratory of the Northern Utilization and Development Division, Agricultural Research Service, U.S.D.A.     

Microdetermination of the major individual isothiocyanates and oxazolidinethione in rapeseed

A method has been developed for the quantitative determination of the major individual thioglucosides (as their aglycones) in rapeseed on a micro scale. The thioglucosides in the meal were hydrolyzed with myrosinase (B.C. 3.2.3.1, thioglucoside glucohydrolase), and the released aglycones were extracted with methylene chloride. The 3-butenyl and 4-pentenyl isothiocyanates were determined by gas-liquid chromatography. The 5-vinyl-2-oxazolidinethione was determined on an aliquot of the same extract by ultraviolet absorption. Five to 20 milligrams of seed or meal were used, and one operator could analyze 24 samples per day. The standard deviation was ±3% for the isothiocyanates and ±6% for the oxazolidinethione. The limit of detection was 0.1 mg per gram of meal for the isothiocyanates and 0.3 mg per gram of meal for the oxazolidinethione. Small amounts of phenylethyl isothiocyanate and two unidentified isothiocyanates were also found.     

异硫氰酸酯的制备及应用

异硫氰酸酯作为一类重要的有机合成中间体,其制备及应用受到广泛关注。笔者综述了异硫氰酸酯的多种制备方法及其在化合物合成、生物技术方面的应用,并对糖基异硫氰酸酯这类特殊的异硫氰酸酯的应用作了较详尽的阐述。     

Isothiocyanates Stimulating Oviposition by the Diamondback Moth, Plutella xylostella

Recognition of cabbage as a host plant for the diamondback moth (DBM) has previously been shown to depend on compounds that are extracted by soaking intact foliage in chloroform. Analysis of such chloroform extracts by open column chromatography has now resulted in the isolation of highly active fractions that elicit oviposition on treated filter papers. Further separation of these fractions by high-performance liquid chromatography revealed the presence of two distinct groups of active compounds that may be classified as volatile and non-volatile. The two prominent volatile components were separated and identified by mass spectrometry as the isothiocyanates, iberin (3-methylsulfinylpropyl isothiocyanate) and sulforaphane (4-methylsulfinyl-3-butenyl isothiocyanate). Subsequent bioassays of a range of isothiocyanates showed that iberin and sulforaphane were the most active of those tested. Other isothiocyanates with sulfur in the side chain were also active, whereas alkyl and phenyl isothiocyanates had only limited activity. In electrophysiological experiments, electroantennograms (EAGs) indicated positive responses of moth antennae to the isothiocyanates that were most active in behavioral assays. Since sulforaphane has been identified as a major inducer of anticarcinogenic activity in mouse tissue, a synthetic analog (exo-2-acetyl-5-isothiocyanatonorbornane) that shows similar inducer activity was tested on DBM. This bicyclic analog was highly active in both behavioral and EAG assays, suggesting similarity in receptor sites for the two types of biological activity.     

Effect of some isothiocyanates on the hydrogenation of canola oil

Sulfur compounds were added to refined and bleached canola oil before hydrogenation in the form of allyl, heptyl and 2-phenethyl isothiocyanates, and the effects on hydrogenation rate, solid fat content and percentagetrans fatty acids were determined. The poisoning effect was most pronounced with allyl isothiocyanate and least with phenethyl isothiocyanate. As the amount of added sulfur increased, the hydrogenation rate decreased. Of the three isothiocyanates used, allyl isothiocyanate caused formation of larger amounts oftrans isomers. An increased sulfur level in the oil resulted in increased solid fat content andtrans isomer level. Allyl isothiocyanate also caused formation of larger amounts of solid fat than other isothiocyanates at all levels of sulfur addition.     

A role for isothiocyanates in plant resistance against the specialist herbivore Pieris rapae

We experimentally reanalyzed the classic interaction between Pieris rapae, a specialist lepidopteran herbivore, and isothiocyanates (mustard oils) that are characteristic phytochemicals of the Brassicaceae. Previous investigations have suggested that P. rapae is unaffected by isothiocyanates. Using whole plants, root extracts, and a microencapsulated formulation of allyl isothiocyanate, we now show that isothiocyanates reduce herbivore survival and growth, and increase development time, each in a dose-dependent manner. Neither the substrate allyl glucosinolate, nor myrosinase, the enzyme that results in the breakdown of glucosinolates, negatively affected P. rapae. Thus, we present strong evidence for a role for isothiocyanates in plant resistance against the specialist herbivore P. rapae.     

Determination of volatile sulfur compounds in canola oil

A simple and sensitive method for the quantitative determination of volatile isothiocyanates in canola oil has been developed. The method is based on the specific absorbance of isothiocyanates in the infrared region. The results obtained were confirmed by gas liquid chromatography using a flame photometric detector. The various volatile isothiocyanates isolated from the oil were allyl isothiocyanate, 3-butenyl isothiocyanate, 4-pentenyl isothiocyanate and 2-phenethyl isothiocyanate. Their identities were confirmed by mass spectroscopy and by retention times. The recoveries of sulfur from volatile sulfur compounds by this method ranged from 93.6% to 101.1% when compared to the amount determined by gas liquid chromatography. The coefficients of variability of volatile sulfur compounds in canola oils ranged from 1.7% to 3.2%. The sulfur content represented by the volatile sulfur compounds comprised 21.7% of the sulfur determined by the Raney nickel method for crude oil, 36.6% for refined oil and 22.7% for refined, bleached and deodorized oil.     

An HPLC method for simultaneous quantitation of individual isothiocyanates and oxazolidinethione in myrosinase digests of rapeseed meal

A simple, rapid and precise method for simultaneous quantitation of individual isothiocyanates and oxazolidinethione inmyrosinase digests of rapeseed meal has been developed. The method consists of inactivation of native myrosinase activity present in the seedmeal, followed by digestion with mustard myrosinase (thioglucoside glucohydrolase, EC 3.2.3.1) to hydrolyze rapeseed glucosinolates quantitatively to isothiocyanates and oxazolidinethione. These hydrolytic products are extracted in methylene chloride as soon as they are formed and finally resolved by a reverse phase high pressure liquid chromatography (HPLC) technique on a μ Bondapak C₁₈ column using aqueous acetonitrile as solvent and an ultraviolet (UV) absorbance detector set at 254 nm. The lower limits of quantitation by this method in a single aliquot applied to the column were 0.2 μg for the isothiocyanates and 0.01 μg for the oxazolidinethione. Recoveries of allyl isothiocyanate, oxazolidinethione and sinigrin added toB. juncea, prior to digestion, were quantitative and averaged at 94.5, 93.0 and 91.2 percent with standard deviations of 1.5, 3.3 and 2.8 percent, respectively. The butenyl and pentenyl isothiocyanates and oxazolidinethione in Tower (B. napus) and Candle (B. campestris) rapeseeds, and allyl isothiocyanate inB. juncea were the major hydrolytic products of glucosinolates. The identity of peaks corresponding to these compounds on a HPLC chromatogram was confirmed by mass spectroscopy.     

Effect of Visual Cues and a Mixture of Isothiocyanates on Trap Capture of Cabbage Seed Weevil, Ceutorhynchus assimilis

The effect of trap design, trap color, and a mixture of isothiocyanates on the capture of Ceutorhynchus assimilis (Paykull) was studied in a series of field experiments. Unbaited yellow water traps, a yellow sticky box trap, and a yellow sticky card trap, mounted vertically, or at 45° to the vertical with the yellow card facing upwards were effective for capturing seed weevils, but a horizontal yellow sticky card trap caught few. White, green, and black traps were unattractive. During migratory periods, trap catch could be enhanced two to four times with a lure consisting of a mixture of allyl, 3-butenyl, 4-pentenyl, and 2-phenylethyl isothiocyanates, but this bait did not attract in a trap with ineffective design. The sticky card trap, mounted at 45° to the vertical and baited with the isothiocyanate mixture, may be useful for monitoring movement of C. assimilis during migratory periods. However, during the colonization phase, lures of either a mixture of isothiocyanates or of allyl isothiocyanate alone were not attractive.