A CONVERGENT SYNTHESIS OF（E．E，E）－3，7，13－TRIMETHYL－6－（i－PROPENYL）－7，14－DIHYDROXY－2，8，12－TETRADECATRIEN－1－METHYLAL

ＡＣＯＮＶＥＲＧＥＮＴＳＹＮＴＨＥＳＩＳＯＦ（Ｅ．Ｅ，Ｅ）－３，７，１３－ＴＲＩＭＥＴＨＹＬ－６－（ｉ－ＰＲＯＰＥＮＹＬ）－７，１４－ＤＩＨＹＤＲＯＸＹ－２，８，１２－ＴＥＴＲＡＤＥＣＡＴＲＩＥＮ－１－ＭＥＴＨＹＬＡＬ￥ＹｉｑｉａｎＷａｎ；ＪｉｎｇＹ...     

ASYMMETRIC SYNTHESIS ⅩⅩⅧ: ENANTIOSELECTIVE REDUCTION OF AROMATIC KETONES CATALYZED BY NEW CHIRAL CATALYST-(4R,8R,9S)-CAMPHANE[8,9-b]-1,3,2-OXATHIOBOROLIDINE

ＡＳＹＭＭＥＴＲＩＣＳＹＮＴＨＥＳＩＳⅩⅩⅧ：ＥＮＡＮＴＩＯＳＥＬＥＣＴＩＶＥＲＥＤＵＣＴＩＯＮＯＦＡＲＯＭＡＴＩＣＫＥＴＯＮＥＳＣＡＴＡＬＹＺＥＤＢＹＮＥＷＣＨＩＲＡＬＣＡＴＡＬＹＳＴ－（４Ｒ，８Ｒ，９Ｓ）－ＣＡＭＰＨＡＮＥ［８，９－ｂ］－１，３，...     

质谱与生命科学

本文以实验表明了谱学，特别是快原子轰击质谱（ＦＡＢ－ＭＳ）、电喷雾电离质谱（ＥＳＩ－ＭＳ）、串联质谱（ＭＳ－ＭＳ）以及有底物的激光解吸电离飞行时间质谱（ＭＡＬＤＩ－ＴＯＦ－ＭＳ）等技术在解决生物物质－肽－蛋白质等的一级结构难题中的特定作用，而这些结构难题往往是常规的生物不方法－Ｅｄｍａｎ降解法、ＤＮＡ转泽法等所无能为力的。虽然文中讨论的例子仅涉及到肽、蛋白质的结构修饰，同理，它也可以广泛应用于其他     

海绵Spongia sp.化学成分的研究（I）

应用气相色谱－质谱联用技术从海绵Ｓｐｏｎｇｉａ ｓｐ．中分离鉴定出４个化学成分：１．－氯－２,２－二对氯苯基乙烯（ＤＤＭＵ,Ｉ）、１,１－二氯－２,２－二对氯苯基乙烯（ＤＤＥ,Ⅱ）、１,１－二氯－２,２－二对氯苯乙烷（ＤＤＤ,Ⅲ）和角鲨烯（Ⅳ）。前３个化合物是首次从Ｓｐｏｎｇｉａ属海绵中分离得到。     

有机锡化合物的电喷雾电离质谱

报道了一系列有机锡ＲＲＰ（Ｓ）ＳＳｎ（Ｃｙ）３化合物的电喷雾电离质谱（ＥＳＩ－ＭＳ）及碰撞诱导解离质谱（ＣＩＤ－ＭＳ）,总结了其谱图特征,讨论了其碎裂机理,为该类化合物的鉴定提供了依据。     

STUDIES ON THE ADDITION REACTION OF GRIGNARD REAGENTS TO α－CINNAMOYLKETENE（1，3－PROPYLENE）DITHIOACETALS

ＳＴＵＤＩＥＳＯＮＴＨＥＡＤＤＩＴＩＯＮＲＥＡＣＴＩＯＮＯＦＧＲＩＧＮＡＲＤＲＥＡＧＥＮＴＳＴＯα－ＣＩＮＮＡＭＯＹＬＫＥＴＥＮＥ（１，３－ＰＲＯＰＹＬＥＮＥ）ＤＩＴＨＩＯＡＣＥＴＡＬＳＱｕｎＸｉｎｇＦＡＮＧ；ＣｈｕｎＬＩＮ；ＳｈｕＪｉａＺＨＡＮＧ；...     

胺固化端环氧基二硅氧烷动力学及性能研究

合成了１，３－二甲基－１，３－二乙基－１，３－双［３－（２，３－环氧丙氧基）丙基］二硅氧烷（ＴＥＤＳ）．对其与二正丁胺的模型反应、与ＤＤＭ（４，４’－二氨基二苯基甲烷）的固化反应劝力学研究表明，反应对ＴＥＤＳ为一级反应．ＴＥＤＳ改性环氧Ｅ—５１体系的动态力学性能、冲击性能和形态结构的研究表明，随改性体系中ＴＥＤＳ含量的增加，体系的玻璃化温度是线性下降、冲击强度增大、冲击试样的断裂面渐渐显现出韧性断裂的特征．     

α-呋喃酯类化合物在EI电离条件下的质谱特征

总结和归属了α－呋喃甲酸酯、α－呋喃甲醇酯、α－呋喃丙烯酸酯以及α－呋喃环在电子电离质谱（ＥＩＭＳ）中的主要裂解方式和特征,给出各化合物主要碎片离子的来源和结构。上述３类不同α－呋喃酯在ＥＩＭＳ中的基峰离子分别为９５、８１和１２１。α－呋喃离子是３类α－呋喃酯的共同碎片离子,由其裂解产生的２９、３８和４１的碎片离子也是３类α－呋喃酯的共同特征离子     

1—酰氧（胺）—2,8,9—三氧杂—5—氮杂—1—锡杂三环（3.3.3.0^1. …

合成了１４个新化合物，１－酰氧（胺）基－２，８，９－三氧杂－５－氮杂－１－锡杂三环（３．３．３．０＾１．５）十一烷，由ＩＲ，＾１ＨＮＭＲ，＾１３ＣＮＭＲ和＾１１９ＳｎＮＭＲ及元素分析确定其结构，该类化合物在ＣＤＣｌ３中可能形成六配位化合物，而在ＤＭＳＯ中，溶剂分子参与Ｓｎ原子配位，聚合体解聚为六配位化合物。     

含MoFe3Se4类立方烷核芯簇合物的合成与结构表征

室温下［Ｅｔ_４Ｎ］_２ＭｏＳｅ_４, ＦｅＣｌ_２和 Ｒ_２ＮＣＳ_２Ｎａ在 ＤＭＦ和 ＣＨ_３ＣＮ混合溶剂中反应,得到含ＭｏＦｅ_３Ｓｅ_４核芯的Ｍｏ－Ｆｅ－Ｓｅ簇合物ＭｏＦｅ_３Ｓｅ_４（μ－Ｒ_２ＮＣＳ_２）_２（Ｒ_２ＮＣＳ_２）_４（Ｒ２＝Ｍｅ_２（１）,Ｅｔ_２（２）,Ｃ_４Ｈ_８（３））．化合物２的单晶Ｘ射线衍射分析表明,其分子结构为２个桥式和４个螫合Ｅｔ_２ＮＣＳ_２~－配体包围的一个扭曲类立方烷Ｍ_４Ｓｅ_４簇核对３个化合物的ＣＶ进行了表征,它们在ＤＭＳＯ溶液中的电化学行为表现出了多电子可逆的传递过程．     

长链不饱和醇的能量分辨质谱

本文用CH4作反应气的化学电离法（CIMS）在三级串连四极质谱仪上完成了四对十四碳不饱和醇蒸发量构体的能量分辩质谱研究。目标化合物的CIMS极其相似，它们各自的准分子离子[M-I]^ 的碰撞活化分解谱也差别不大，但在0-50eV的能量分辨质谱显示了顺、反异构信息，文中讨论了导致顺、反异构体的能量分辨质谱差异的原因。     

Analysis of a series of isomeric oligosaccharides by energy‐resolved mass spectrometry: a challenge on homobranched trisaccharides

Glycans exist as part of glycoproteins and glycolipids, which are involved in a variety of biological functions. The analysis of glycan structures, particularly that of structural isomers, is fundamentally important since isomeric glycans often show distinct functions; however, a method for their structural elucidation has not yet been established. Anomeric configurations, linkage positions and branching are the major factors in glycans and their alteration results in a large diversity of glycan structures. The analysis of vicinally substituted oligosaccharides is extremely difficult because the product ions formed in tandem mass spectrometry (MS/MS) often have the same m/z values. In our endeavor to address the issue, we analyzed a series of homo‐substituted trisaccharides consisting only of glucose by collision‐induced dissociation (CID), especially energy‐resolved mass spectrometry (ERMS). It was found that these structurally related glycans could be distinguished by taking advantage of differences in their activation energies in ERMS. Copyright © 2009 John Wiley & Sons, Ltd.     

Energy‐resolved mass spectrometry for differentiation of the fluorine substitution position on the phenyl ring of fluoromethcathinones

A reliable method for structural analysis is crucial for the forensic investigation of new psychoactive substances (NPSs). Towards this end, mass spectrometry is one of the most efficient and facile methods for the identification of NPSs. However, the differentiation among 2‐, 3‐, and 4‐fluoromethcathinones (o‐, m‐, and p‐FMCs), which are ring‐fluorinated positional isomers part of the major class of NPSs referred to as synthetic cathinones, remains a challenge. This is mostly due to their similar retention properties and nearly identical full scan mass spectra, which hinder their identification. In this study, we describe a novel and practical method for differentiating the fluorine substitution position on the phenyl ring of FMCs, based on energy‐resolved mass spectrometry (ERMS) using an electron ionization‐triple quadrupole mass spectrometer. ERMS measurements showed that the three FMC positional isomers exhibited differences in relative abundances of both the fluorophenyl cation (m/z 95) and the fluorobenzoyl cation (m/z 123). The logarithmic plots of the abundance ratio of these two cations (m/z 95 to m/z 123) as a function of the collision energy (CE) followed the order of o‐FMC < p‐FMC < m‐FMC at each CE, which allowed the three isomers to be unambiguously and reliably differentiated. The theoretical dissociation energy calculations confirmed the relationship obtained by ERMS analyses, and additional ERMS measurements of methylmethcathinone positional isomers showed that the differences in abundance among the FMCs were attributed to the differences in their collision‐induced dissociation reactivities arising from the halogen‐induced resonance effects on the phenyl ring. Moreover, the method for differentiation described herein was successfully applied to the actual samples containing seized drugs. We expect that the described methodology will also contribute significantly to the reliable and accurate structural identification of NPSs in the fields of therapeutic, clinical, and forensic toxicology.     

Distinguishing isomeric pyridylaminated high-mannose (Man7) oligosaccharides based on energy-resolved mass spectra

Analysis of posttranslational modifications of proteins is an important issue for understanding the relationship between protein structure and function. Micro-scale analytical methods capable of elucidating glycan structures are therefore gaining attention in connection with proteomics research. Recent efforts directed toward this goal have successfully distinguished and in some cases identified glycan structures based on collision-induced dissociation (CID) analysis. Despite these advancements, the identification of isomeric glycans such as high-mannose-type oligosaccharides, Man(7)GlcNAc(2), that are closely related structurally, is not yet possible. Using energy-resolved mass spectrometry (ERMS), we found that these isomers could be distinguished by comparing the intensities of certain fragment ions. ERMS is useful because the data obtained can be treated quantitatively. Furthermore, it was found that discrimination can be easily achieved by analyzing only the energy-resolved mass spectra of the sodiated isomeric compounds at the stage of MS(2). Thus, the importance and usefulness of ERMS, which provide the factor of activation energy under CID, in analyzing isomeric molecules are clearly shown.     

Identification of position isomers by energy‐resolved mass spectrometry

This study reports an energy‐resolved mass spectrometric (ERMS) strategy for the characterization of position isomers derived from the reaction of hydroxyl radicals (^●OH) with diphenhydramine (DPH) that are usually hard to differentiate by other methods. The isomer analogues formed by ^●OH attack on the side chain of DPH are identified with the help of a specific fragment ion peak (m/z 88) in the collision‐induced dissociation (CID) spectrum of the protonated molecule. In the negative ion mode, the breakdown curves of the deprotonated molecules show an order of stability (supported by density functional theory (DFT) calculations) ortho > meta > para of the positional isomers formed by the hydroxylation of the aromatic ring. The gas phase stability of the deprotonated molecules [M ? H]^? towards the benzylic cleavage depends mainly on the formation of intramolecular hydrogen bonds and of the mesomeric effect of the phenol hydroxyl. The [M ? H]^? molecules of ortho and meta isomers result a peak at m/z 183 with notably different intensities because of the presence/absence of an intramolecular hydrogen bonding between the OH group and C9 protons. The ERMS approach discussed in this report might be an effective replacement for the conventional methods that requires very costly and time‐consuming separation/purification methods along with the use of multi‐spectroscopic methods. Copyright © 2015 John Wiley & Sons, Ltd.     

Positional isomer differentiation of synthetic cannabinoid JWH‐081 by GC‐MS/MS

Like many new designer drugs of abuse, synthetic cannabinoids (SC) have structural or positional isomers which may or may not all be regulated under law. Differences in acute toxicity may exist between isomers which impose further burden in the fields of forensic toxicology, medicine and legislation. Isomer differentiation therefore becomes crucial from these standpoints as new designer drugs continuously emerge with just minor positional modifications to their preexisting analogs. The aim of this study was to differentiate the positional isomers of JWH‐081. Purchased standard compounds of JWH‐081 and its positional isomers were analyzed by gas chromatography‐electron ionization‐mass spectrometry (GC‐EI‐MS) first in scan mode to investigate those isomers who could be differentiated by EI scan spectra. Isomers with identical or near‐identical EI spectra were further subjected to GC‐tandem mass spectrometry (MS/MS) analysis with appropriate precursor ions. EI scan was able to distinguish 3 of the 7 isomers: 2‐methoxy, 7‐methoxy and 8‐methoxy. The remaining isomers exhibited near‐identical spectra; hence, MS/MS was performed by selecting m/z 185 and 157 as precursor ions. 3‐Methoxy and 5‐methoxy isomers produced characteristic product ions that enabled the differentiation between them. Product ion spectrum of 6‐methoxy isomer resembled that of JWH‐081; however, the relative ion intensities were clearly different from one another. The combination of EI scan and MS/MS allowed for the regioisomeric differentiation of the targeted compounds in this study. Copyright © 2015 John Wiley & Sons, Ltd.     

GC/MS and ESI/MS identification of the new generation plasticizers - cis and trans isomers of some 1,2-cyclohexane dicarboxylic acid di(n- and isononyl) esters

1,2-Cyclohexane dicarboxylic acid diisononyl ester is also known as diisononyl cyclohexane-1,2-dicarboxylate (DINCH) is a complex mixture of the hydrogenation products of diisononyl benzene-1,2-dicarboxylate (DINP). They are the new generation plasticizers used instead of the dialkyl benzene-1,2-dicarboxylate in order to improve the flexibility of polymers (mainly PVC) and strongly reduce the toxic effects on human health during their release from polymers to the environment. The identification of these compounds was done by syntheses of some DINCH constituents, i.e. cis and trans isomers of three di(n- and isononyl) cyclohexane-1,2-dicarboxylates, such as di(3,5,5-trimethylhexyl) cyclohexane-1,2-dicarboxylates, di(2-methyloctyl) cyclohexane-1,2-dicarboxylates and dinonyl cyclohexane-1,2-dicarboxylates by catalytic hydrogenation of appropriate DINP and their analyses by gas chromatography – mass spectrometry (GC/MS) and electrospray - mass spectrometry (ESI/MS) methods. Both GC data (values of the retention times t_R and arithmetic retention indices I_A) and mass spectra obtained for these isomers allowed to determine their chemical structures. ESI/MS mode of analysis of these compounds gives the knowledge about their mass fragmentation without the differentiation between individual cis and trans isomers.     

Development of a mass spectrometric hydroxyl‐position determination method for the hydroxyindole metabolites of JWH‐018 by GC‐MS/MS

One of the many issues of designer drugs of abuse like synthetic cannabinoids (SCs) such as JWH‐018 is that details on their metabolism has yet to be fully elucidated and that multiple metabolites exist. The presence of isomeric compounds poses further challenges in their identification. Our group has previously shown the effectiveness of gas chromatography‐electron ionization‐tandem mass spectrometry (GC‐EI‐MS/MS) in the mass spectrometric differentiation of the positional isomers of the naphthoylindole‐type SC JWH‐081, and speculated that the same approach could be used for the metabolite isomers. Using JWH‐018 as a model SC, the aim of this study was to differentiate the positional isomers of its hydroxyindole metabolites by GC‐MS/MS. Standard compounds of JWH‐018 and its hydroxyindole metabolite positional isomers were first analyzed by GC‐EI‐MS in full scan mode, which was only able to differentiate the 4‐hydroxyindole isomer. Further GC‐MS/MS analysis was performed by selecting m/z 302 as the precursor ion. All four isomers produced characteristic product ions that enabled the differentiation between them. Using these ions, MRM analysis was performed on the urine of JWH‐018 administered mice and determined the hydroxyl positions to be at the 6‐position on the indole ring. GC‐EI‐MS/MS allowed for the regioisomeric differentiation of the hydroxyindole metabolite isomers of JWH‐018. Furthermore, analysis of the fragmentation patterns suggests that the present method has high potential to be extended to hydroxyindole metabolites of other naphthoylindole type SCs in identifying the position of the hydroxyl group on the indole ring. Copyright © 2016 John Wiley & Sons, Ltd.     

利用HPLC-ESI-MS/MS区分黄芩中黄酮C-苷异构体的研究

采用HPLC-ESI-MS/MS联用技术区分了黄芩中两种互为同分异构体的黄酮C-苷类化合物5,7-OH-6-C-阿拉伯糖-8-C-葡萄糖黄酮和5,7-OH-6-C-葡萄糖-8-C-阿拉伯糖黄酮.阐述了黄酮C-苷类化合物同分异构体的电喷雾串联质谱(ESI-MSⁿ)的特征碎裂规律,证明了[M-H-60]^-,[M-H-90]^-及[M-H-120]^-离子是其特征离子.实验结果表明,对于C-6位五碳糖取代和C-8位六碳糖取代的黄酮C-苷二级串联质谱产生的[M-H-60]^-离子(^0,3₅X),其丰度一般大于50%;而对于C-6位六碳糖取代和C-8位五碳糖取代的黄酮C-苷二级串联质谱产生的[M-H-60]^-离子(^0,3₅X),其丰度一般小于50%.据此可区分两种互为同分异构体的黄酮C-苷类化合物.     

HPLC-MS法分离与表征微囊藻毒素

蓝藻水华对淡水湖泊的污染近年来逐渐加剧,其释放的主要有害物质为微囊藻毒素.藻毒素异构体的分离与制备研究对供水安全具有重要的意义.从滇池蓝藻中提取了微囊藻毒素的几种常见异构体并采用高效液相色谱手段对各异构体进行了分离.探讨了不同色谱条件对分离结果的影响,其中的5种异构体得到了很好地分离,使用HPLC-MS对3种含量较多的...