首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 859 毫秒
1.
3-甲基-3-氧杂丁环甲醇的阳离子型开环聚合   总被引:3,自引:0,他引:3  
三元和四元环醚具有较大的环张力而易于聚合.Vandenberg等[1]曾经以(i-Bu3)Al/H2O为引发剂,使3-甲基-3-(三甲基硅氧甲基)氧杂丁环进行开环聚合反应,合成的聚合物水解后得到线形的聚甲基羟甲基醚.本文以BF3·OEt2为引发剂,对3-甲基-3-氧杂丁环甲醇进行直接引发,实现了开环聚合反应,得到基本线形或轻度支化的聚醚多元醇.1 实验部分1.1 聚合物的合成 聚合装置同文献[1].所用试剂按文献[1]方法处理.向烧瓶中加入20mL的二氯乙烷和0.1mol3-甲基-3-氧杂丁环甲…  相似文献   

2.
以DMF作溶剂,在四丁基氟化铵 (TBAF)存在下,对甲基苯基三甲硅基醚(1)和4,4'-二氯二苯砜(2)于100 ℃反应1 h,合成了4,4'-二(4-甲基苯氧基)二苯砜(3),产率为92%;加入催化量的N-溴代丁二酰亚胺(NBS)并在光照条件下,与氧气反应得到中间体-4,4'-二(4-羧基苯氧基)二苯砜(4),其产率达90%;将化合物4与二氯亚砜反应合成目标产物4,4'-二(4-氯甲酰基苯氧基)二苯砜(5),总收率为74.5%(以对甲基苯基三甲硅基醚为基准计算).  相似文献   

3.
建立了池塘养殖水中丁香酚、甲基丁香酚和异丁香酚等3种丁香酚类麻醉剂的残留测定方法。采用正己烷提取,苯基固相萃取柱净化,气相色谱-三重四极杆串联质谱仪进行测定。结果显示,丁香酚、甲基丁香酚和异丁香酚检测限分别为0.05,0.03,0.13μg/L,定量限分别为0.17,0.10,0.43μg/L;在1~200μg/L质量浓度范围内,3种化合物线性良好,相关系数r>0.9996;丁香酚、甲基丁香酚和异丁香酚回收率范围分别为98.5%~101.6%,98.5%~104.6%和98.4%~101.3%,相对标准偏差范围分别为2.3%~5.3%,3.2%~4.1%和2.4%~3.6%。方法能够满足养殖水中丁香酚、甲基丁香酚和异丁香酚同时测定的需要。  相似文献   

4.
不同产地石菖蒲的挥发性成分研究   总被引:1,自引:0,他引:1  
采用气相色谱-质谱联用技术(GC-MS)对安徽安庆、浙江金华、河南嵩县和河南驻马店4个产地石菖蒲的挥发性成分进行了研究,共鉴定出45种化学成分,并测定了其相对含量.其中,相对含量大于1%的共有挥发性成分为β-细辛醚、γ-细辛醚、α-细辛醚和顺式-甲基异丁香酚.这4种共有挥发性成分的保留时间及相对含量可作为石菖蒲鉴别和质...  相似文献   

5.
藜芦醛(3,4-二甲氧基苯甲醛,又称甲基香兰素)是一种具有香荚兰(Vanilla beans)型香味的合成香料。在1875年已由Tiemann通过香兰素(Vanillin)的甲基化而制得。以后,Fichter和Briner又分别通过电化学氧化和臭氧化从异甲基丁香酚而获得。迄今关于藜芦醛的合成主要还是从香兰素的甲基化和在藜芦醚(Veratrole)上通过Gattermann反应引入甲酰基来制取。我们在国产香茅属植物精油的系统研究中,发现贵州罗甸野生的青香茅(Cymbopogon tortilis)精油中含有大约56%的甲基丁香酚。为了开展国产香茅油的综合利用,我们研究了从甲  相似文献   

6.
石芳  寿旦  金米聪  王宏伟  陈旭光  朱岩 《色谱》2022,40(2):139-147
随着麻醉剂广泛用于渔业生产过程和水产品运输等领域,建立水产品中麻醉剂残留的检测方法具有重要意义.由于水产品基质复杂且麻醉剂残留水平低,因此需要合适的前处理方法以提高检测灵敏度.该研究基于分散固相萃取-高效液相色谱,建立了一种同时检测水产品中普鲁卡因、丁氧卡因、三卡因、丁香酚、甲基丁香酚、异丁香酚、甲基异丁香酚7种麻醉剂...  相似文献   

7.
将丁香酚(Eul)与丙烯酸甲酯进行衍生化反应,合成了一种新型的丁香酚半抗原4-(4羟基-3-甲氨基苯基)-丁-2-烯酸(Eul-Aca)。采用活性酯法将丁香酚半抗原与乙二胺异硫氰酸荧光素(EDF)偶联,分别制备了同源和异源荧光示踪物。通过比较不同示踪物的抗体稀释度和灵敏度,优化反应时间等检测条件,建立了一种检测水产品中丁香酚的荧光偏振免疫分析法(FPIA)。结果表明:异源示踪物(Eul-AcaEDF)具有更优的检测灵敏度,抗体稀释度为1/200,反应时间仅需5 min。该方法的半抑制浓度(IC50)为11.2μg/L,检测线性范围为1.1~111.5μg/L,检出限(LOD)为0.24μg/L。实际样品中丁香酚的加标回收率为80.6%~107.4%,相对标准偏差(RSD)<15%。FPIA检测结果与气相色谱-质谱(GC-MS)法结果具有良好的一致性(r=0.993),适用于水产品中丁香酚的残留检测。  相似文献   

8.
多种谱学方法研究环氧乙烷/四氢呋喃共聚醚的热氧降解   总被引:2,自引:0,他引:2  
采用电子自旋共振(ESR)、傅里叶变换红外光谱(FT-IR)和多种核磁共振(NMR)技术研究了环氧乙烷/四氢呋喃共聚醚的热氧降解,表 征了近20种产物结构碎片,并对EO和THF两种链节的降解作了定量讨论。共聚醚的氧化降解发生在醚键氧碳上,遵循自由基氧化机理,最后形成大量的甲酸酯、碳酸酯等酯类以及甲基、亚甲二氧基和醇,此外还检测到过氧化氢和半缩甲醛结构。分析表明共聚醚中THF链节的降解程度明显大于EO链节,而且降解容易发生在两种链节交替连接处。抗氧剂2,6-二叔丁基-4-甲基酚(BHT)不仅降低了共聚醚的氧化降解程度,还改变了降解产物的结构分布,显著抑制了碳酸酯和亚甲二氧基结构的生成,相对增加了羟基和端甲基结构。  相似文献   

9.
以合成的一种新化合物三甘醇-二(2,2'-乙酰丙酮-4,4'-甲基)苯基醚作配体,在无水甲醇中合成了七种希土氯化物的配合物,确定其组成是LnLCl(Ln:La,Ce,Nd,Sm,Eu,Gd和Dy),L:三甘醇-二(2,2'-乙酰丙酮-4,4'-甲基)苯基醚。由IR,UV,TG-DTG和display status  相似文献   

10.
气相-质谱分析北细辛根和根茎中的挥发性成分   总被引:17,自引:0,他引:17  
张峰  王龙星  罗茜  肖红斌  梁鑫淼  蔡少青 《色谱》2002,20(5):467-470
 采用 质谱联用技术对北细辛根和根茎的挥发性成分进行分离分析 ,鉴定出了 36种化学成分 ,主要成分为十五烷、甲基丁香酚、黄樟醚、3 ,5 二甲氧基甲苯等。对照北细辛根和根茎的分析结果可以发现 ,两者的挥发性成分基本相同 ,但含量有较大差异 ,这为北细辛的临床合理用药及质量控制标准的确定提供了实验依据。  相似文献   

11.
Some constituents found in natural flavorings are known to exhibit toxic properties. We developed a rapid method for quantifying 12 flavor-related compounds in cigarette tobacco using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. Using selected ion monitoring, we quantified and positively identified coumarin; pulegone; piperonal and nine alkenylbenzenes, including trans-anethole, safrole, methyleugenol and myristicin in one or more brands of cigarettes. In 62% of 68 brands analyzed, we detected one or more of the flavor-related compounds ranging from 0.0018 to 43 microg/g. Toxic properties of these flavor-related compounds may constitute an additional health risk related to cigarette smoking.  相似文献   

12.
Alkenylbenzenes, including eugenol, methyleugenol, myristicin, safrole, and estragole, are potentially toxic phytochemicals, which are commonly found in foods. Occurrence data in foods depends on the quality of the analytical methodologies available. Here, we developed and compared modern reversed-phase high performance liquid chromatography (HPLC) and stacking-micellar electrokinetic chromatography (MEKC) methods for the determination of the above alkenylbenzenes in food flavouring ingredients. The analytical performance of HPLC was found better than the stacking-MEKC method. Compared to other HPLC methods found in the literature, our method was faster (total run time with conditioning of 15 min) and able to separate more alkenylbenzenes. In addition, the analytical methodology combining an optimized methanol extraction and proposed HPLC was then applied to actual food flavouring ingredients. This methodology should be applicable to actual food samples, and thus will be vital to future studies in the determination of alkenylbenzenes in food.  相似文献   

13.
The alkaloid accumulation dymanics in Veratrum lobelianum were investigated. Jervine was found from 0.02 to 0.11% in the subterranean part at all vegetation stages. The jervine content was greatest in subterranean plant organs, reaching a maximum (0.3%) during natural dying off of aerial organs. Jervine, a natural analog of serotonin, can be used as a specific fibroblast growth factor. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 57–59, January–February, 2006.  相似文献   

14.
Asymmetric curcumin analogues as potential anticancer compounds. The purpose of this study was to synthesize product 5-benzo[1,3]dioxol-5-yl-1-phenyl-penta-2,4-dien-1-one uses the method conventional and microwaves. Product 5-benzo[1,3]dioxol-5-yl-1-phenyl-penta-2,4-dien-1-one can be synthesized from the cullilawan oils with several stages, among others; isolation safrole, isomerization, oxidation and condensation reactions. Isolation of safrole from cullilawanoils performed using NaOH solution and purified using distillation fractionation pressure reduction produces 19.30% safrole are tested for purity by GCMS and for the identification of the structure is done by using FTIR and 1H-NMR. The safrole isomerization performed using KOH without solvent at a temperature of 120oC for 8 hours resulted isosafrole (91.53%) which consists of cis-isosafrol and trans-isosafrol. Oxidation isosafrole performed using KMnO4 in acidic conditions using a phase transfer catalyst tween 80 at a temperature of < 30oC and separation by silica gel resulted in 65.63% piperonal were tested with the GCMS and identification using FTIR and 1H-NMR. Products asymmetrical curcumin analogous made in the condition alkaline by conventional methods for three hours produce 99.55%, a method of microwaves in 140 watts for two minutes produce 82.82%.  相似文献   

15.
Safrole [5-allylbenzo[d][1,3]dioxole] was subjected to photochemical oxidation reaction with hydrogen peroxide in the presence of sodium lamp to give the corresponding epoxy derivative [5-oxiranylmethylbenzo[1,3]dioxole. The thermal oxidation of safrole with 3-chloroperoxybenzoic acid at room temperature gave the same epoxide derivative in quantitative yield. Antibacterial studies were carried out on safrole and its photoproducts (safrole epoxide and safrole hydroperoxide). The results revealed that safrole hydroperoxide was the most effective than safrole epoxide than safrole against Gram-positive bacteria Bacillus subtilis ATCC6633, Staphylococcus aureus ATCC25923, and Gram negative bacteria Escherichia coli ATCC25422. This result proved that safrole derivatives are beneficial to human health, having the potential to be used for medical purposes.  相似文献   

16.
建立了超声溶剂提取和分散液液微萃取(DLLME)相结合的提取、净化前处理技术,采用气相色谱-质谱法分析了烟用添加剂中的黄樟素、侧柏酮、龙蒿脑、胡薄荷酮、甲基丁香酚、香豆素、6-甲基香豆素和7-甲氧基香豆素8种烷基苯类香味有害物。对分散液液微萃取溶剂及其体积、分散剂及其体积、萃取时间等条件进行了优化。在最佳实验条件下,8种有害物的线性范围为0.4~928μg/L(r2≥0.998 9),检出限为0.04~0.24μg/L,定量下限为0.13~0.80μg/L,富集倍数为140~208倍,方法的加标回收率为90%~100%,相对标准偏差为2.4%~6.7%。与行业推荐的测定方法相比,该方法具有灵敏度高、富集效果好、回收率高等优点。  相似文献   

17.
Summary A method is described for the preparation of a safrole chemically bonded phase to silica gel. Its structure on silica has been investigated by FTIR, solid state FT-13CNMR and29SiNMR spectra. The safrole phase has strong -donor ligands on the silica surface so that the separation of nitroaromatic compounds can be demonstrated as a donor-acceptor complex-chromatographic separation in high-pressure liquid chromatography. A comparison of retentions on the safrole phase, 3-phenylpropylmethylsilyl phase and RP-18 is also described.

Teil 3: siehe [1]  相似文献   

18.
As part of our program to prepare substituted rtaphthoquinones with potential biological activity1 we have synthetized 6, 7-methyleriedioxy-3-alky 1 lawsones (5a-g) from natural safrole (1) and carboxylic' acids (~50% overall yield).  相似文献   

19.
Bioinsecticides are regarded as important alternatives for controlling agricultural pests. However, few studies have determined the persistence of these compounds in stored grains. This study aimed at optimizing and validating a fast and effective method for extraction and quantification of residues of safrole (the main component of Piper hispidinervum essential oil) in cowpea beans. It also sought to assess the persistence of this substance in the grains treated by contact and fumigation. The proposed method used headspace solid-phase microextraction (HS-SPME) and gas chromatography with a flame ionization detector (GC/FID). Factors such as temperature, extraction time and type of fiber were assessed to maximize the performance of the extraction technique. The performance of the method was appraised via the parameters selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy. The LOD and LOQ of safrole were 0.0057 and 0.019 μg kg−1, respectively and the determination coefficient (R2) was >0.99. The relative recovery ranged from 99.26 to 104.85, with a coefficient of variation <15%. The validated method was applied to assess the persistence of safrole residue in grains, where concentrations ranged from 1.095 to 0.052 µg kg−1 (contact) and from 2.16 to 0.12 µg kg −1 (fumigation). The levels measured up from the fifth day represented less than 1% of the initial concentration, proving that safrole have low persistence in cowpea beans, thus being safe for bioinsecticide use. Thus, this work is relevant not only for the extraction method developed, but also for the possible use of a natural insecticide in pest management in stored grains.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号