伏立康唑的波谱学特征和结构确证

目的:确定伏立康唑的化学结构。方法:通过红外光谱（IR）、高分辨质谱（HRMS）、核磁共振谱（NMR）、热重分析仪/差示扫描量热仪（TGA/DSC）、X-射线粉末衍射（PXRD）对伏立康唑进行结构表征。结果:对IR、HRMS、NMR检测结果进行解析和归属,确定了样品的分子结构;通过TGA/DSC和PXRD的检测结果分析,确定了样品为B晶型。结论:综合运用多种谱学方法确证了伏立康唑的结构,为其质量研究提供参考依据。     

盐酸雷洛昔芬结构确证的波谱学研究

确定了标题化合物的结构.采用红外光谱(IR)、紫外光谱(UV) 一维(1H、13C)和二维(1H-1H COSY、HMQC、HMBC)核磁共振光谱(NMR)、质谱(MS)对标题化合物进行结构确证,对所有的1HNMR和13CNMR谱进行了归属;讨论了红外吸收光谱峰所对应的官能团的振动形式,并详细分析了标题化合物MS中主要碎片离子的裂解途径.经波谱学研究确证了标题化合物的结构.     

左氧氟沙星有关物质的合成及其结构确证

介绍了左氧氟沙星3个有关物质及其合成方法,并对其进行了高分辨质谱(HRMS)和核磁共振谱(NMR)确证以及碳氢信号的归属,为左氧氟沙星质量研究提供了杂质对照品.     

米洛沙星的波谱特征与结构确证

采用紫外吸收光谱、红外光谱、质谱、核磁共振光谱和单晶X-射线衍射法对米洛沙星进行结构确证。讨论了紫外光谱和红外光谱的特征,详细归属了~1HNMR和~(13)CNMR谱信号,结合X-射线衍射分析结果,最终确证其分子结构。     

利奈唑胺的波谱学特征和结构确证

目的:确定利奈唑胺的化学结构.方法:通过紫外光谱(UV)、红外光谱(IR)、高分辨质谱(HRMS)、核磁共振谱、热分析(TGA/DSC)、粉末X-射线(PXRD)对利奈唑胺进行结构表征.结果:对UV、HRMS、NMR检测结果进行解析和归属,确定了样品的分子结构;通过IR、TGA/DSC和PXRD的检测结果分析,确定了样...     

加替沙星环合酯的波谱数据和结构确证

通过UV、IR、HRMS、NMR(1H NMR、13C NMR、DEPT135、1H-1H COSY、HMQC、HMBC、D2O)数据对合成加替沙星、巴洛沙星和莫西沙星的关键中间体加替沙星环进行结构表征,并对其核磁共振波谱进行了详细的解析和归属.综合运用多种谱学方法确证了其的结构,为其质量研究提供参考.     

三氯卡班的波谱学数据与结构确证

建立了一种仪器分析技术确证三氯卡班化学结构的方法。采用紫外光谱、红外光谱、高分辨质谱、核磁共振、热重分析、差示扫描量热法和单晶X-射线衍射法对三氯卡班进行结构表征。通过对紫外和红外光谱的特征峰解析、~1HNMR和~(13)CNMR谱信号的详细归属、热分析(TGA/DSC)结果解析以及X-射线衍射技术证明,最终确证了三氯卡班的分子结构。     

β-蒿甲醚的波谱数据和结构确证

通过高分辨质谱、核磁共振波谱、热分析、X射线粉末衍射对β-蒿甲醚进行了结构表征,确定了样品的分子结构和晶型。综合运用多种谱学方法确证了β-蒿甲醚的结构,为其质量研究提供参考。     

Synthesis and Structural Elucidation of NSC Auxiliary Dispersing Agents

The synthesis, characterization, structural elucidation, and application of the dispersant (NSC) obtained from condensation of β-naphthalene sulphonic acid and formaldehyde are described. The one pot process from naphthalene, sulphuric acid, and formaldehyde leads to reproducible condensate products with n = 13 and 14 naphthalene nuclei. The ¹H and ¹³C NMR spectra were recorded in D₂O (representative spherical shape) and DMSO (representative rod-like shape). Bleaching leads to the recovery of excellent super pure material.     

Structural Elucidation of Isomeric Bianthryls Generated from Anthracene Pyrolysis

Abstract

Among the primary products of anthracene pyrolysis at 1213 K are the six isomeric bianthryls, which we have analyzed by high performance liquid chromatography with diode-array detection (HPLC/DAD), ultraviolet spectroscopy, and gas chromatography-mass spectrometry (GC-MS). When separated by reverse-phase HPLC or GC, the isomers elute in the order A,B,C,D,E,F, and only the elution orders of isomers C and D are reversed in normal-phase HPLC. Analysis of our product mixture after spiking with a 9,9″-bianthryl reference standard shows that A is 9,9″-bianthryl. The distinctive ultraviolet spectrum of 2,2″-bianthryl, the only isomer whose anthracene moieties are coplanar, confirms the identity of F as this bianthryl. Theoretical and experimental information in the literature on the effect of substituents on anthracene's ultraviolet absorption spectrum provides valuable guidance in interpreting the ultraviolet spectra of the bianthryls. Certain features of these spectra, combined with the principles governing chromatographic elution order, lead to the identification of the remaining bianthryls as: B, 1,9″-bianthryl; C, 2,9″-bianthryl; D, 1,1″-bianthryl; and E, 1,2″-bianthryl.     

N-Fmoc-2-(正癸胺基)乙醛的波谱数据和结构确证

N-Fmoc-2-(正癸胺基)乙醛是合成特拉万星的侧链,通过紫外吸收光谱(UV)、红外吸收光谱(IR)、高分辨质谱(HRMS)、核磁共振波谱(1HNMR、13C NMR、DEPT135、1H COSY、HMQC、HMBC)对其进行了结构表征,并对其核磁共振波谱进行了详细的解析和归属.综合运用多种谱学方法确证了其的结构,...     

Structural Elucidation and Bioactivity of Biflavonoids from the Stems of Wikstroemia taiwanensis

Three new biflavonoids, wikstaiwanones A-C (1-3), along with four known compounds (4-7) were isolated from the stems of Wikstroemia taiwanensis (Thymelaeaceae). Their structures were elucidated by spectroscopic analysis. Compounds 4 and 5 showed antitubercular activity against Mycobacterium tuberculosis with MIC values of 15 μg/mL, respectively.     

Determination and Structural Elucidation of Triacylglycerols in Krill Oil by Chromatographic Techniques

The content of triacylglycerols (TAG) in krill oil is generally omitted from the labels of commercial supplements and unacknowledged in studies aimed at proving its health benefits. The present study demonstrates that TAG compounds, in addition to phospholipids and lysophospholipids, are an important lipid class in pure krill oil. The fatty acid composition of TAG molecules from krill oil and their distribution on the backbone of TAG structures were determined by gas chromatography and liquid chromatography tandem mass spectrometric, respectively. The content of omega 3 polyunsaturated fatty acids (n-3 PUFA) was similar to those reported in the literature for fish oil. It was estimated that 21 % of n-3 PUFA were at the sn-2 position of TAG structures. To our knowledge, this is the first determination and structural characterization of TAG in pure krill oil supplements.     

The Elucidation of Charge-Transfer-Induced Matrix Effects in Environmental Aerosols Via Real-Time Aerosol Mass Spectral Analysis of Individual Airborne Particles

Matrix effects in real-time aerosol mass spectrometry (RTAMS) were investigated using Standard Reference Materials (SRMs) obtained from the National Institute of Standards and Technology (NIST). Suppression of major component ions by much less concentrated species was observed. Attempts were made to mimic the ion suppression using binary systems but were unsuccessful. Data are presented that suggest the origin of the matrix effect is charge transfer induced neutralization in the ablation plume.