共查询到20条相似文献,搜索用时 125 毫秒
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核磁共振在抗生素药物定量分析中的应用 总被引:18,自引:1,他引:17
随着核磁共振仪器的逐渐普及与实验技术的不断发展,在抗生素药物分析中核磁共振波谱(NMR)除了用于化合物的结构测定外,日益成为药物定量分析的一种重要手段,有些已被作为药物分析的法定方法[1]。 与其它波谱方法相同,核磁共振定量分析是通过比较特定的吸收峰的强度实现的。因此,只要样品中每个组分有1个或1组特征互不重叠的吸收峰,都有可能用核磁共振波谱法进行定量分析。 NMR方法的灵敏度虽不如红外、紫外光谱或高效液相色谱,其优点为可同时测定药物制剂中的多种有效成分,具有简单、准确、专一性高和不破坏样品等优点。不仅已被用于定量测定大量的药理活性药物,对于药物制剂分析,赋形剂一般不干 相似文献
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南海叶状牡丹珊瑚化学成分的研究 总被引:1,自引:0,他引:1
从中国南海叶状牡丹珊瑚中分离出两个化合物。经紫外(UV)、红外(IR)、核磁共振光谱(^1HNMR,^13CNMR)、质谱(EIMS,HRMS)等波谱分析,确定其结构为:3-甲基-6-氨基嘌呤和胆甾醇。 相似文献
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随着现代科学技术的发展,各种新的测试手段的提高,使波谱解析在天然化合物结构测定中起着越来越重要作用,已成为我们认识微观分子的最重要手段之一[1-4],它也是我院药学类、中药类及研究生等专业学生必需学习的一门重要专业基础课程,其教学任务主要是讲述紫外光谱、红外光谱、核磁共振和质谱的基本原理与一般解析方法,熟悉紫外与共轭系统,红外与官能团,氢谱与质子状态,碳谱与碳骨架,质谱与分子量之间的关系,通过教与学, 相似文献
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The emergence of chemically masked illicit drugs represents a challenge to global initiatives that are working to prevent their manufacture and distribution. Targeted analytical techniques currently used by law enforcement to identify unknown materials rely on spectroscopic and spectrophotometric databases that do not currently include some of these compounds, making their identification challenging. This study aimed to update compound spectral libraries to aid in the rapid detection and identification of these masked drugs, as well as to provide insight into their synthetic procedures. Five commonly employed protecting groups, acetyl, p‐tosyl, methoxycarbonyl, Fmoc, and t‐Boc, were appended to pseudoephedrine, ephedrine, methamphetamine, and MDMA. Characterization was carried out using NMR, GC‐MS, FTIR, high‐resolution LC‐MS/MS, and common screening color tests. Some of the methoxycarbonyl and t‐Boc derivatives and all of the Fmoc derivatives showed partial or full thermal degradation or rearrangement during GC‐MS analysis, while LC‐MS/MS analysis did not always show characteristic fragmentation that would allow unambiguous assignment of the structure. Restricted rotation in some of the derivatives meant that NMR assignments could only be made using NMR spectra acquired at elevated temperature. Therefore, GC‐MS and LC‐MS/MS analyses serve complementary roles for these derivatives, with NMR providing confirmation of structure for the pure materials if necessary. 相似文献
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雷尼替丁枸橼酸铋的合成及其表征 总被引:2,自引:0,他引:2
以盐酸雷尼替丁为原料,经碱化制得雷尼替丁(碱基),再与枸橼酸铋反应制得消化性溃疡治疗药-雷尼替丁枸橼酸铋。经元素分析、红外光谱、核磁共振谱、质谱等确证了结构。 相似文献
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Detailed studies on the 13C and 1H NMR spectra of chromomycins A2 and A3, olivomycins A and B, and their derivatives clarified the assignment of many signals which had been unassigned or erroneously reported in the literatures. The revised assignments for chromomycin A3 and olivomycin A include the assignment of a key 13C signal used to discuss the saccharide linkage in question. Structure analyses based on the revised assignments support the alpha,1----3-bond between components of the disaccharide moiety in the molecules. Some general information useful for structure analysis of saccharides is also reported. 相似文献
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E Borowski J Golik J Zieliński L Falkowski P Ko?odziejczyk J Pawlak 《The Journal of antibiotics》1978,31(2):117-123
The complete structure of mycoheptin, a heptaene macrolide antifungal antibiotic, has been established as I by chemical degradation methods and MS and 1H NMR analysis of the products. 相似文献
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在筛选免疫抑制剂的过程中,得到具有免疫抑制剂活性的化合物SIIA9268A,经理化性质和光谱分析(IR、UV、1H-NMR、13C-NMR、APT、1H-1HCOSYNMR、13C-1HCOSYNMR、EI-MS),得知该化合物属于新型大环内酯类,与rapamycin同质。 相似文献
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A new compound, methyl 3-(4'-hydroxyphenethylamino)-1,4-dihydro-1,4-dioxonaphthalene-2-carboxylate (1) was isolated from Chirita eburnea. Its structure was elucidated on the basis of 1D NMR, 2D NMR and MS analysis. 相似文献