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71.
Doping control in sport is mandatory to detect and to control the use of prohibited substances. Due to the growing number of targets, the analysis of doping compounds and their metabolites is carried out using established screening methods. However, detection of anabolic steroids with 4,9,11-triene structure in urine is problematic, so it is necessary to improve the methods.We review the state of the art in doping-control analysis of 4,9,11-trien-3-one steroids, providing an overview of the screening and confirmatory methods developed for these analytes in human urine. First, we review chromatographic techniques. We discuss difficulties in the derivatization of those compounds prior to gas chromatography analyses. In recent years, liquid chromatography has been the preferred technique in drug testing in sport, due to the reduced sample pre-treatment, improved limits of detection and comprehensiveness. We also report on advances and limitations of immunochemical techniques for the analysis of this group of substances. 相似文献
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73.
本文对月光花素甲(Calonyctin A)的整体分子结构分析加以完善并进行总结。前文报道月光花素甲是两个分子量相差28a.m.u的糖甙类同系物分子的混合物。这两个分子(简称M_1和M_2)分别称为月光花素甲(Ⅰ)与月光花素甲(Ⅱ)(Calonyctm A_1,CalonyctinA_2),分子量分别为938与910。它们分别含 相似文献
74.
M. Lamidi T. Martin-Lopez E. Ollivier F. Crespin-Maillard L. Nze Ekekang G. Balansard 《Chromatographia》1995,41(5-6):581-584
Summary A reversed-phase HPLC determination of 11 saponins and an alkaloid glycoside inNauclea diderrichii bark is described. Quantitative analysis of quinovic acid 3-0-α-L-rhamnopyranoside which is one of the main saponins was
determined, using Chrysanthelline A as internal standard. The complete separation was achieved in 47 minutes. The method of
quantification was validated. 相似文献
75.
一种新的测定一维同核全相关的NMR技术 总被引:7,自引:3,他引:4
提出一种新的基于MDY混合脉冲的可测定一维同核全相关的核磁共振技术.称为一维自旋回波MDY相干转移(lD-SEMDY)实验.结果表明.它具有下列突出优点:一是不用Z-滤波技术就可以得到纯吸收型的一维全相关谱(lD-TOCSY).与同类技术相比,操作简便.可节省测定时间.应用范围较广;二是所测定亚谱中的信号归属通过改变混合时间和延迟时间可以得到确定;三是相干转移非常有效.远程磁化转移信号的灵敏度比较高,对弱偶合的自旋体系也可进行测定.以甙类化合物为例讨论了它在谱峰高度重叠的有机结构测定中的应用. 相似文献
76.
Jun Gang YIN 《中国化学快报》2006,17(11):1457-1459
A new flavanone (2S)-5, 7, 2', 5'-tetrahydroxy-flavanone 1 together with a new flavanone glycoside (2S)-5, 7, 2', 5'-tetrahydroxy-flavanone 7-O-13-D-glucopyranoside 2, were isolated from the dry roots of Scutellaria baicalensis. Their structures were elucidated on the basis of spectroscopic data. 相似文献
77.
ShuJieHOU ChuanChunZOU PingShengLEI DeQuanYU 《中国化学快报》2005,16(5):593-596
Using thioglycosides as donors, trimethylsilyl trifluoromethanesulfonate (TMSOTf) and N-iodosuccinimide(NIS) as promoter, a modified procedure for the glycosylation of spirostanol was developed. A series of saponins were synthesized in mild condition with excellent yields. 相似文献
78.
79.
80.
Dennis W. Bennett Tasneem A. Siddiquee Kristen L. Murphy Daniel T. Haworth Zhengjie He William A. Donaldson 《Journal of chemical crystallography》2003,33(11):897-902
The X-ray crystal structure of the title compound, as crystallized from methanol–methylene chloride was determined. The asymmetric unit contains two steroid molecules, which differ primarily in the orientation of the aromatic rings of the benzyl ethers. The title compound crystallizes in the noncentrosymmetric space group P2(1), with a = 7.558(2), b = 16.673(3), c = 18.735(4) Å, = 97.610(10)°, and D
calc = 1.268 g cm–1 for Z = 4. 相似文献