排序方式: 共有32条查询结果,搜索用时 31 毫秒
1.
ValeryN. Kalinin IgorV. Shishkov SergeyK. Moiseev ElviraE. Shults GenrikhA. Tolstikov NataliaI. Sosnina PavelV. Petrovskii KonstantinA. Lyssenko Helmut Schmidhammer 《Helvetica chimica acta》2006,89(5):861-869
In a search for starting materials for the preparation of 7,8‐fused morphine alkaloid derivatives, 8‐[(1E‐2‐phenylethenyl]codeinone dimethyl ketal ( 4 ) and 8‐[(1E‐2‐phenylethenyl]codeine ( 5 ) were prepared. These dienes were used as substrates in the Diels–Alder reactions. Compound 5 formed the ‘normal’ adduct 12 with N‐phenylmaleimide, while compound 4 behaved in reactions with dienophiles as the ‘masked’ diene 11 , a 8‐[(1E)‐2‐phenylethenyl]‐substituted thebaine, yielding the corresponding 19‐substituted 6,14‐endo‐etheno‐6,7,8,14‐tetrahydrothebaines. Specifically, reaction of 4 with methyl vinyl ketone gave rise to 19‐[(1E)‐phenylethenyl]thevinone ( 14 ) whose structure was elucidated by an X‐ray diffraction analysis. The thebaine derivative 11 was also prepared from 4 . 相似文献
2.
A kinetic method for the determination of codeine, based on its inhibitor action on the catalytic decomposition of hydrogen peroxide by cobalt(II), is presented. It has been found that the effect of codeine is most pronounced in the presence of 5% v/v ethylene glycol. The reaction is followed photometrically. Codeine can be determined in concentrations ranging from 0.80×10–5
M to 2.4×10–5
M. The method has been applied to the determination of codeine in pharmaceutical preparations. 相似文献
3.
Summary The behaviour of codeine reineckate and codeine tetraphenylborate membrane electrodes has been observed with a respectiveNernstian response of 58 and 56 mV/decade for 9.3×10–5–1.3×10–3
M codeine sulfate solutions. The workingpH ranges were 5–8 and 4–8, respectively. The selectivity towards sugars, amines, amino acids, cations, and some pharmaceutical compounds was found to be satisfactory. The isothermal temperature coefficient was 0.0014 V/°C. The electrodes were applied successfully for the determination of codeine in some pharmaceutical dosage forms with a relative standard deviation range of 0.16–0.30% and an average recovery of 98.6±0.6%.
Herstellung und Charakterisierung einer codeinselektiven Elektrode
Zusammenfassung Das Verhalten von Codeinreineckat- und Codeintetraphenylboratmembranelektroden in 9.3×10–5–1.3×10–3 M Codeinsulfatlösungen wurde untersucht (Nernstscher Response: 58 bzw. 56 mV/Dekade). Der verwendetepH-Bereich für die beiden Elektroden war 5–8 bzw. 4–8. Ihre Selektivität gegenüber Zuckern, Aminen, Aminosäuren, Kationen und einigen pharmazeutisch aktiven Verbindungen ist zufriedenstellend. Der isotherme Temperaturkoeffizient beträgt 0.0014V/°C. Die Elektroden wurden erfolgreich zur Bestimmung von Codein in einigen pharmazeutischen Präparaten eingesetzt (relative Standardabweichung: 0.16–0.30%).相似文献
4.
人体血中吗啡浓度的GC/MS测定法 总被引:4,自引:0,他引:4
本实验采用磷酸可待因作内标,经液相萃取、乙酸酐衍生化处理后,用GC/MS的选择离子定量模型(SIM)测定肿瘤病人体内吗啡的血药浓度。方法的最低检出限为0.95ng/mL,在1.0~60.0ng/mL的浓度范围内,标准曲线呈良好的线性,r>0.998,日内日间误差小于9.0%,回收率达96%,已成功地应用在8例肿瘤病人口服30mg吗啡控释片的药代动力学的研究上。 相似文献
5.
Qilin Li Prof. Dr. Hongbin Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(46):16379-16382
In this paper, a new strategy towards the synthesis of codeine and morphine is reported. This new approach features a cascade cyclization to construct the dihydrofuran ring, and an intramolecular palladium catalyzed C?H olefination of unactivated aliphatic alkene to install the morphinan ring system. 相似文献
6.
高效毛细管电泳法测定罂粟壳中生物碱的含量 总被引:12,自引:2,他引:10
采用高效毛细管电泳法测定罂粟壳中可待因、吗啡和罂粟碱的含量,结果表明可待因的加样回收率为96.61%,吗啡为95.90%,罂粟碱为95.37%。方法简便、准确、重现性好,可作为生物碱的质量控制方法。 相似文献
7.
人尿液中麻黄碱和可待因的液-液-液微萃取/高效液相色谱法测定 总被引:2,自引:0,他引:2
建立了液-液-液微萃取与高效液相色谱联用技术快速分析尿样中麻黄碱和可待因的方法.优化得到的最佳萃取条件:萃取溶剂为80μL苯,接受相为1.0μL 0.2 mol·L-1的HCI,搅拌速率为80 r·min-1,萃取时间为40 min.在该条件下.获得了高的富集因子(大于117倍).方法的线性范围为麻黄碱0.05-10mg·L-1,可待因0.10-10 mg·L-1,相关系数(r)大于0.997,检出限分别为0.025 mg·L-1和0.05 mg·L-1,相对标准偏差小于9%.该方法能有效地去除尿样中的干扰物质,有机溶剂消耗少,萃取效率高,可同时测定尿样中麻黄碱和可待因. 相似文献
8.
Younes Valadbeigi Vahideh Ilbeigi Maryam S. Mirsharifi 《Journal of mass spectrometry : JMS》2020,55(10)
Atmospheric pressure chemical ionizations (APCIs) of morphine, codeine, and thebaine were studied in a corona discharge ion source using ion mobility spectrometry (IMS) at temperature range of 100°C–200°C. Density functional theory (DFT) at the B3LYP/6‐311++G(d,p) and M062X/6‐311++G(d,p) levels of theory were used to interpret the experimental data. It was found that in the presence of H3O+ as reactant ion (RI), ionization of morphine and codeine proceeds via both the protonation and carbocation formation, whereas thebaine participates only in protonation. Carbocation formation (fragmentation) was diminished with decrease in the temperature. At lower temperatures, proton‐bound dimers of the compounds were also formed. Ammonia was used as a dopant to produce NH4+ as an alternative RI. In the presence of NH4+, proton transfer from ammonium ion to morphine, codeine, and thebaine was the dominant mechanism of ionization. However, small amount of ammonium attachment was also observed. The theoretical calculations showed that nitrogen atom of the molecules is the most favorable proton acceptor site while the oxygen atoms participate in ammonium attachment. Furthermore, formation of the carbocations is because of the water elimination from the protonated forms of morphine and codeine. 相似文献
9.
《Analytical letters》2012,45(5):641-652
Abstract A rapid, simple and specific procedure for the simultaneous assay and determination of enantiomeric purity of pharmaceutical grade cocaine hydrochloride and codeine tablets is described. The procedure is as accurate, faster and more specific than the U. S. P. or N. F. methods. 相似文献
10.
Surface ionization of the opium alkaloids morphine, codeine, thebaine, papaverine, and narcotine was investigated by mass spectrometry. It was shown that the alkaloid molecules were ionized with high efficiency through surface ionization. The mass spectra of morphine, codeine, and thebaine exhibited series of lines for quasimolecular ions with elimination of up to nine H atoms from the opiates that was accompanied by heterogeneous aromatization of the rings and their skeletal rearrangement. The results were compared with GC-MS data from electron ionization. 相似文献