微波照射下膦酰基/硫甲基烯酮硫代缩醛和N-取代膦酰 基/硫甲基硫代碳酸酯的 合成

在微波照射下方便、高收率地合成了新奇的膦酰基杂环的合成子-膦酰基/硫甲基烯酮硫代缩醛和N-取代膦酰基/硫甲基硫代碳酸酯,实验表明微波照射大大加快了反应速率和提高了反应产率。     

O-芳基苯基硫代膦酰肼及其旋光活性腙

某些膦酰肼及其衍生物只有生物活性。本文通过O-芳基苯基硫代膦酰氯与50％水合肼反应合成了O-芳基苯基硫代膦酰肼(Ⅰ),在有些反应中还分离到N,N′-双[O-芳基苯基硫代膦酰基]肼(Ⅱ)。Ⅰ与(-)-薄荷酮反应得旋光活性薄荷酮腙(Ⅲ),由于磷原子是手性的,产物为非对映异构体。     

2-(芳氧基苯基硫代膦酰基)-1,2,3σ^2-二氮磷杂环戊二烯的合成

研究了芳氧基苯基硫代膦酰基酮腙与三氯化磷的环化反应, 成功地合成了2-N上带有硫代膦酰基的3-氯1,2,3-二氮磷杂环戊烯(3)及二配位磷化物2-硫代膦酰基1,2,3σ^2-二氮磷杂环戊二烯(4)。     

N′-叔丁基-N-取代酰基(硫)脲类化合物的合成及生物活性测定

将叔丁基引入到酰基 (硫 )脲骨架中 ,设计合成了 8个未见文献报道的N′ 叔丁基 N 取代酰基脲及N′ 叔丁氨基羰基 N 取代酰基硫脲类化合物 ,其结构经元素分析、IR和1 HNMR得到确证 .初步的生物活性测试结果表明部分化合物具有较好的除草活性     

含二茂铁基的硫代碳酰腙和缩氨基硫脲的合成

硫代碳酰腙和氨基硫脲衍生物具有一定的生理活性,可作为某些金属离子的特效试剂,本文报道在乙醇-醋酸介质中通过取代氨基硫脲,硫代碳酰腙与不同的二茂铁衍生物缩合,合成了新的缩氨基硫脲和硫代碳酰腙衍生物.     

1-异烟酰基-4-芳酰基氨基硫脲化合物的研究

进一步研究了卤代芳酰异硫氰与异烟酰肼反应,制得一系列1-异烟酰基-4-卤代芳酰基氨基硫脲,并观察了这些新药物的抗结核菌性能,其中以1-异烟酰基-4-对碘苯甲酰基-氨基硫脲抗结核菌作用最强。     

N,N′-硝基苯酰基取代苯酰氨基硫脲的合成与生物活性

酰氨基硫脲类化合物不仅具有广谱抗菌性能,还具有极好的杀虫和植物生长调节活性[1～3],因而引起许多国内外学者对硫脲类化合物的合成及其化学结构与生物活性关系方面的研究[4～8].为了进一步研究不同的取代基团对此类化合物生物活性的影响,作者用硝基苯酰基异硫氰酸酯与芳基酰肼加成制得相应的N,N′-硝基苯酰基取代苯酰氨基硫脲(Ⅲ),并初步测定了它们抑制大肠杆菌和枯草杆菌生长的生物活性.这些化合物尚未见文献报道.     

N,N'-甲撑-双(2-氨基-5-硫酮-1,3,4-噻二唑)及其有关化合物的~(15)N 核磁共振研究

近几年~(?)N—NMR 已成为研究含氮有机化合物和生物分子化学的有力工具。它虽有信噪比低的致命弱点,但又有化学位移变化范围大、对电子效应和环境效应敏感的优点。在本文中,我们利用天然丰度的~(?)N-NMR 对 N,N′-甲撑-双(2-氨基-5-硫酮-1,3,4-噻二唑)(1)及其中间体及原料2-氨基-5-硫酮-1,3,4-噻二唑(2)、氨基硫脲(3)、双硫脲(4)进行了结构分析     

1—苯乙酰基—4—芳酰基氨基硫脲的合成及其在碱催化下的环化反应

1-酰基-4-芳基氨基硫脲类化合物在碱性条件下环化为具有广泛生物活性的3-取代基-4-芳基-1,2,4-三唑啉-5-硫酮的反应报道甚多,但1,4-位都含羰基的酰氨基硫脲在碱性条件下环化反应迄今报道较少。我们曾研究了1-[5-(α-萘)-2H-四唑-2-乙酰基]-4-芳酰基氨基硫脲和1-(α-萘乙酰基)-4-芳酰基氨基硫脲在碱催化下环化为3-取代基-4-芳酰基-1,2,4-三唑啉-5-硫酮的反应,它们在低浓度下均有一定的生物活性。本文研究了1-苯乙酰基-4-芳酰基氨基硫脲1_(a～m)在1mol/L K_2CO_3溶液催化下的环化反应,得到环化产物3-苄基-4-芳酰基-1,2,     

5-取代苯胺基-6-苯基-1, 2, 4-三嗪-3-硫酮的合成

苯甲酰基-N-取代苯基硫代甲酰胺和氨基硫脲反应, 首先在酸性介质中形成缩氨基硫脲, 然后在碱性介质(pH=8~9)中环化, 生成5-取代苯胺基-6-苯基-1, 2, 4-三嗪-3-硫酮。本文合成10个新的该类杂环化合物。     

Optimization of matrix-assisted laser desorption/ionization time-of-flight collision-induced dissociation using poly(ethylene glycol)

Details of the optimization of the collision-induced dissociation (CID) process, using a collision cell on a matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometer, are described using poly(ethylene glycol) 1000 (PEG 1000) as a model analyte. The effects of collision gas identity (helium, air, and argon), as well as collision gas pressure, on the resulting MS/MS data were investigated. With PEG 1000, helium was found to give the best results with respect to signal-to-noise (S/N) ratio. The optimum pressure for each gas was found to be in the range where the precursor ion signal was attenuated to approximately 30-50% for helium and 40-60% for argon. The effect of cation choice (Li, Na, and K) on the CID of PEG was also studied. CID spectra were produced for each, but PEG cationized with lithium was found to produce the spectra with the highest S/N ratio. The MALDI-TOF CID spectra that were generated for PEG were compared with the high-energy and low-energy MS/MS spectra obtained from a sector mass spectrometer and from a triple quadrupole mass spectrometer, respectively. The results observed for PEG confirm that CID on a MALDI-TOF mass spectrometer is a high-energy MS/MS technique.     

Structure Analysis and Ion Abundance in CID- MS- MS Spectra of Isomeric Oligosaccharides Using Quadrupole Time-of- flight Mass Spectrometry: Distinguishing between Isomeric Oligosaccharides

N - Linked oligosaccharide were analyzed by using electrospray ionization (ESI) quadrupole time - of- fight mass spectrometry(Q - Tof MS).The isomers showed the same MS and collisioninduced desociation(CID) MS - MS spectra in the m/z values because the sequence of the sugar residues was the same.But the relative ion abundance of the specific fragment ion was greatly different between the isomers.So, the isomeric oligosacchariedes were distinguished by using the ion abundance in their CID -MS - MS spectra.Discussing the ion abundance in accurate level, quantitative analysis of the mixtures of isomers were also performed.     

Synthesis of benzofurazan derivatization reagents for carboxylic acids in liquid chromatography/electrospray ionization-tandem mass spectrometry

The applicability of benzofurazan derivatization regents to carboxylic acids analysis in LC/ESI-MS/MS (high-performance liquid chromatography/electrospray ionization tandem mass spectrometry) was examined. The product ion spectra of DAABD-AE {4-[2-(N,N-dimethylamino)ethylaminosulfonyl]-7-(2-aminoethylamino)-2,1,3-benzoxadiazole}, DAABD-PZ {4-[2-(N,N-dimethylamino)ethylaminosulfonyl]-7-N-piperazino-2,1,3-benzoxadiazole}, DAABD-PiCZ {4-[4-carbazoylpiperidin-1-yl]-7-[2-(N,N-dimethylamino)ethylaminosulfonyl]-2,1,3-benzoxadiazole}, DAABD-ProCZ {4-[2-carbazoylpyrrolidin-1-yl]-7-[2-(N,N-dimethylamino) ethylaminosulfonyl]-2,1,3-benzoxadiazole} and DAABD-Apy {4-[2-(N,N-dimethylamino)ethylaminosulfonyl]-7-(3-aminopyrrolidin-1-yl)-2,1,3-benzoxadiazole}, and their acetylated compounds were obtained. An intense fragment ion at m/z 151 corresponding to (dimethylamino)ethylaminosulfonyl moiety was observed in each spectra, suggesting that these reagents were suitable for ESI-MS/MS analysis. DAABD-AE, DAABD-APy and DAABD-PZ were applied to the analysis of octanoic acid and it was found that DAABD-AE and DAABD-APy gave high signal intensity suitable for LC/ESI-MS/MS.     

1，3，2—二氮磷杂环戊烷类化合物的合成

为了寻找新的除草剂,我们研究了N,N′-二取代苯磺酰乙二胺与不同类型磷化合物的反应(图1)。实验表明取代乙二胺不能与亚磷酸酯反应,而与亚磷酰胺反应,发现产物及其硫化物具有一定的除草活性。     

Investigation of the copper binding site on the human islet amyloid polypeptide hormone

The metal ion binding sites of human islet amyloid polypeptide (hIAPP) have been investigated to explain the biological activity difference in the fibril formation process. The structures of [hIAPP...Cu (or Al)](n+) and [hIAPP17-30...Cu]2+ complex were investigated by electrospray ionization-mass spectrometry (ESI-MS). The fragmentation patterns of [hIAPP...Cu [or Al)](n+) and [hIAPP17-30...Cu]2+ complex were analyzed by tandem mass spectrometry (MS/MS) and multi-stage mass spectrometry (MS3) spectra. The [hIAPP+Cu+H]3+, [hIAPP+Al+H]4+ and [hIAPP17-30+Cu]2+ complexes were observed in MS spectra. The Cu binding site of hIAPP is suggested to be the N22-F-G-A-I26 part for the [hIAPP+Cu+H]3+ gas-phase complex. The original hIAPP conformation was supposed to be changed by the interaction between the Cu ion and the N22-F-G-A-I26 part in the [hIAPP+Cu+H]3+ gas-phase complex.     

Separation and identification of DMPO adducts of oxygen-centered radicals formed from organic hydroperoxides by HPLC-ESR,ESI-MS and MS/MS

Many electron spin resonance (ESR) spectra of 5,5-dimethyl-1-pyrroline N-oxide (DMPO) radical adducts from the reaction of organic hydroperoxides with heme proteins or Fe(2+) were assigned to the adducts of DMPO with peroxyl, alkoxyl, and alkyl radicals. In particular, the controversial assignment of DMPO/peroxyl radical adducts was based on the close similarity of their ESR spectra to that of the DMPO/superoxide radical adduct in conjunction with their insensitivity to superoxide dismutase, which distinguishes the peroxyl adducts from the DMPO/superoxide adduct. Although recent reports assigned the spectra suggested to be DMPO/peroxyl radical adducts to the DMPO/methoxyl adduct based on independent synthesis of the adduct and/or (17)O-labeling, (17)O-labeling is extremely expensive, and both of these assignments were still based on hyperfine coupling constants, which have not been confirmed by independent techniques. In this study, we have used online high performance liquid chromatography (HPLC or LC)/ESR, electrospray ionization-mass spectrometry (ESI-MS) and tandem mass spectrometry (MS/MS) to separate and directly characterize DMPO oxygen-centered radical adducts formed from the reaction of Fe(2+) with t-butyl or cumene hydroperoxide. In each reaction system, two DMPO oxygen-centered radical adducts were separated and detected by online LC/ESR. The first DMPO radical adduct from both systems showed identical chromatographic retention times (t(R) = 9.6 min) and hyperfine coupling constants (a(N) = 14.51 G, a(H)(beta) = 10.71 G, and a(H)(gamma) = 1.32 G). The ESI-MS and MS/MS spectra demonstrated that this radical was the DMPO/methoxyl radical adduct, not the peroxyl radical adduct as was thought at one time, although its ESR spectrum is nearly identical to that of the DMPO/superoxide radical adduct. Similarly, based on their MS/MS spectra, we verified that the second adducts (a(N) = 14.86 G and a(H)(beta) = 16.06 G in the reaction system containing t-butyl hydroperoxide and a(N) = 14.60 G and a(H)(beta) = 15.61 G in the reaction mixture containing cumene hydroperoxide), previously assigned as DMPO adducts of t-butyloxyl and cumyloxyl radical, were indeed from trapping t-butyloxyl and cumyloxyl radicals, respectively.     

Mass spectral characterization of tetracyclines by electrospray ionization,H/D exchange,and multiple stage mass spectrometry

Electrospray ionization (ESI) and collisionally induced dissociation (CID) mass spectra were obtained for five tetracyclines and the corresponding compounds in which the labile hydrogens were replaced by deuterium by either gas phase or liquid phase exchange. The number of labile hydrogens, x, could easily be determined from a comparison of ESI spectra obtained with N2 and with ND3 as the nebulizer gas. CID mass spectra were obtained for [M + H]+ and [M - H]- ions and the exchanged analogs, [M(Dx) + D]+ and [M(Dx) - D]- , and produced by ESI using a Sciex API-III(plus) and a Finnigan LCQ ion trap mass spectrometer. Compositions of product ions and mechanisms of decomposition were determined by comparison of the MS(N) spectra of the un-deuterated and deuterated species. Protonated tetracyclines dissociate initially by loss of H2O (D2O) and NH3 (ND3) if there is a tertiary OH at C-6. The loss of H2O (D2O) is the lower energy process. Tetracyclines without the tertiary OH at C-6 lose only NH3 (ND3) initially. MSN experiments showed easily understandable losses of HDO, HN(CH3)2, CH3 - N=CH2, and CO from fragment ions. The major fragment ions do not come from cleavage reactions of the species protonated at the most basic site. Deprotonated tetracyclines had similar CID spectra, with less fragmentation than those observed for the protonated tetracyclines. The lowest energy decomposition paths for the deprotonated tetracyclines are the competitive loss of NH3 (ND3) or HNCO (DNCO). Product ions appear to be formed by charge remote decompositions of species de-protonated at the C-10 phenol.     

Synthesis,Crystal Structure and Photophysical properties of a Novel Molecule Containing a Triarylamine and an Oxadiazole Units

2-{3-[2-（4-N,N-Di-p-tolylaminophenyl)ethenyl]phenyl}-5-(4-bromophenyl)-1,3,4-oxadiazole(1) containing triarylamine and 2,5-diaryl-1,3,4-oxadiazole units was prepared by hornerWitting reactions.The structure of the compound was confirmed by ^1H NMR,IR ,MS and elemental analyses.The crystal structure of 1 was determined by X-ray diffraction analysis.UV absorpiton spectra and photoluminescent spectra were measured.     

The structure of the FeNO group in two metastable states (MS1 and MS2) of the nitroprusside anion in Na2[Fe(CN)5NO].2H2O. Infrared spectra and quantum chemistry calculations for the normal and the 15NO and N18O isotopic substituted substance

Low temperature infrared spectra of light induced metastable states MS1 and MS2 of the nitroprusside anion in Na(2)[Fe(CN)(5)NO].2H(2)O, isotopically normal and substituted with (15)NO and N(18)O, are presented and discussed. As a consequence of the relatively high population of the MS2 state achieved by further irradiation with 1064 nm light of samples previously irradiated with 488.0 nm light, new bands were seen for the first time, and others, previously reported, were confirmed. The comparison of the spectral data obtained for the FeNO moiety of the isotopically normal as well as of the (15)NO and N(18)O substituted anion with the results of quantum chemical (DFT) calculations support the assignment of the bands which appear after successive irradiations to MS1, the linear Fe(eta(1)-ON) linkage isomer, and to MS2, the side-bound Fe(eta(2)-NO) isomer.     

Investigations of preferential solvation on 1,4-dimethoxy-3-methyl anthracene-9,10-dione

Synthesis, spectroscopic and thermal studies of some complexes of a new N(2)-Schiff base ligand of N(1),N(2)-bis((E)-2-methyl-3-phenylallylidene)ethane-1,2-diamine (L) with a general formula of MLX(2) (M = Zn(II), Cd(II) and Hg(II); X = Cl(-), Br(-), I(-), SCN(-) and N(3)(-)) are described. The ligand and its complexes were characterized by elemental analysis, molar conductance, UV-vis spectra, FT-IR spectra, MS, (1)H NMR and (13)C NMR spectra. The conductivity measurement as well as spectral data indicated that the complexes are non-electrolyte. (1)H and (13)C NMR spectra have been studied in DMSO-d(6) and/or CDCl(3). The thermal behavior of the complexes shows weight loss by decomposition of the anions and ligand segments in the subsequent steps. Activation thermodynamic parameters of decomposition such as E*, ΔH*, ΔS* and ΔG* were calculated from TG curves.