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Miral Dizdaroglu Dieter Henneberg Clemens Von Sonntag 《Journal of mass spectrometry : JMS》1974,8(1):335-345
Aldoses, ketoses, deoxy-aldoses, deoxy-keto-aldoses, lactones, deoxy-lactones and other similar compounds are readily reduced by NaBD4 to the corresponding polyalcohol. Their trimethylsilyl ethers show characteristic mass spectra which allow firm assignments of the position of deuteration and hence of the nature of the starting sugar compound. The g.c./m.s. coupling technique even allows trace analysis since full information can be derived from the most intense fragments of the mass spectra. 相似文献
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Weak anion-exchange and reversed-phase high-performance liquid chromatographic methods for peptide separations were compared using a tryptic digest of "rat small myelin basic protein". In these experiments, a number of tryptic peptides that were not resolved on the reversed-phase column could be separated on the weak anion-exchange column, and in other instances, as might be expected, reversed-phase chromatography provided better resolution of certain peptides than did the weak anion-exchange method. The results obtained strongly suggest that the combined use of these two methods of separation, which utilize different selectivities, can provide an excellent improvement in resolving power for a number of peptide separations. 相似文献
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Synthesis,characterization and biological application of cyclometalated heteroleptic platinum(II) complexes
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A series of square planar cyclometalated heteroleptic platinum(II) complexes of the type [(C^N)Pt(O^O)] [where, O^O is a β‐diketonato ligand of acetylacetone (acac), C^N = cyclometalating 7‐(4‐fluorophenyl)‐5‐phenylpyrazolo[1,5‐a]pyrimidine (L1), 7‐(4‐chlorophenyl)‐5‐phenylpyrazolo[1,5‐a]pyrimidine (L2), 7‐(4‐bromophenyl)‐5‐phenylpyrazolo[1,5‐a]pyrimidine (L3), 7‐(4‐methoxyphenyl)‐5‐phenylpyrazolo[1,5‐a]pyrimidine (L4), 5‐phenyl‐7‐(p‐tolyl)pyrazolo[1,5‐a]pyrimidine (L5)] have been design, synthesized and characterized. All compounds have been screened for biological studies like in vitro antibacterial, in vitro cytotoxicity, cellular level cytotoxicity, absorption titration, viscosity measurements, fluorescence quenching analysis, molecular docking and DNA nuclease. The intrinsic binding constants (Kb) of compounds with HS‐DNA has been obtained in range of 2.892–0.242 × 105 M?1. All the compounds bound with HS DNA by partial intercalative mode of binding. MIC study has been carried out against Gram(+ve) and Gram(?ve) bacterial species. In vitro cytotoxicity against brine shrimp lethality bioassay has been also carried out. The LC50 values of the ligands and complexes have been found in range of 56.49–120.22 μg/mL and 6.71–11.96 μg/mL, respectively. 相似文献
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Design,synthesis, pharmacological evaluation and DNA interaction studies of binuclear Pt(II) complexes with pyrazolo[1,5‐a]pyrimidine scaffold
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Miral V. Lunagariya Khyati P. Thakor Bhargav N. Waghela Chadramani Pathak Mohan N. Patel 《应用有机金属化学》2018,32(4)
Substituted pyrazolo[1,5‐a]pyrimidine ligands were synthesized by cyclization, using 3‐(thiophen‐2‐yl)‐1H‐pyrazol‐5‐amine with substituted enones (3‐phenyl‐1‐(pyridin‐2‐yl)prop‐2‐en‐1‐one) in presence of KOH and DMF as solvent to form cyclic aromatic compounds. The substituted pyrazolo[1,5‐a] pyrimidine based binuclear PtII complexes containing neutral tetradentated ligands have general formula [Pt2(5a–5f)Cl4], (where, (5a ‐5f) = pyrazolo[1,5‐a] pyrimidine ligand). This compounds were characterized by physicochemical and spectroscopic method like elemental analyses, UV‐Visible, FT‐IR, EDX, TGA, molar conductivity, magnetic susceptibility measurements, mass spectroscopy, 1H and 13C NMR method. The square planar geometry was predicted by electronic spectral study. All PtII compounds were evaluated by antimicrobial assay, in vitro brine shrimp assay, in vivo cellular level bioassay using S. Pombe cells and anti‐tuberculosis study. LC50 (50% lethal concentration) values of compounds are observed between 6.450 ‐ 102.07 μg/mL. UV‐vis absorption titration, competitive displacement assay, molecular docking and viscosity measurement were carried out to examine the binding type and binding strength of complexes. The binding studies suggest partial intercalative binding mode of the complexes and the observed binding constant (Kb) values are found in the order of 6d > 6b > 6c > 6a > 6e > 6 f. The anti‐proliferative cytotoxicity of the synthesized PtII complexes (6a‐6f) were tested against the HCT‐116 (Human Colorectal Carcinoma) cancer cell line. 相似文献
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Jaruga P Jabil R McCullough AK Rodriguez H Dizdaroglu M Lloyd RS 《Photochemistry and photobiology》2002,75(2):85-91
A DNA glycosylase specific for UV radiation-induced pyrimidine dimers has been identified from the Chlorella virus Paramecium Bursaria Chlorella virus-1. This enzyme (Chlorella virus pyrimidine dimer glycosylase [cv-pdg]) exhibits a 41% amino acid identity with endonuclease V from bacteriophage T4 (T4 pyrimidine dimer glycosylase [T4-pdg]), which is also specific for pyrimidine dimers. However, cv-pdg possesses a higher catalytic efficiency and broader substrate specificity than T4-pdg. The latter excises 4,6-diamino-5-formamidopyrimidine (FapyAde), a UV radiation- and hydroxyl radical-induced monomeric product of adenine in DNA. Using gas chromatography-isotope-dilution mass spectrometry and y-irradiated DNA, we show in this work that cv-pdg also displays a catalytic activity for excision of FapyAde and, in addition, it excises 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyGua). Kinetic data show that FapyAde is a better substrate for cv-pdg than FapyGua. On the other hand, cv-pdg possesses a greater efficiency for the extension of FapyAde than T4-pdg. These two enzymes exhibit different substrate specificities despite substantial structural similarities. 相似文献
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Characterization of free radical-induced damage to DNA by the combined use of enzymatic hydrolysis and gas chromatography-mass spectrometry 总被引:1,自引:0,他引:1
M Dizdaroglu 《Journal of chromatography. A》1986,367(2):357-366
The use of gas chromatography-mass spectrometry (GC-MS) for characterization of free radical-induced base damage to DNA is presented. Damage introduced to DNA by reactive oxygen species such as hydroxyl radicals appears to play an important role in mutagenesis, carcinogenesis and aging. Elucidation of the chemical nature of such DNA lesions is necessary for the assessment of their biological consequences and enzymatic repair. DNA exposed to radiation-generated hydroxyl radicals in aqueous solution was hydrolyzed to 2'-deoxyribonucleosides with a mixture of DNase I, venom and spleen exonucleases and alkaline phosphatase. The hydrolysate was subsequently trimethylsilylated and analyzed by GC-MS. A large number of DNA lesions were separated and identified. Mass spectra obtained were interpreted on the basis of the typical fragmentation pathways of trimethylsilylated nucleosides. The use of GC-MS with selected-ion monitoring facilitated the detection of these lesions at the very low quantities and radiation doses (below 10 Gray) that might be relevant to those in biological systems. 相似文献
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Miral Dizdaroglu Dieter Henneberg Clemens Von Sonntag Man Nien Schuchmann 《Journal of mass spectrometry : JMS》1977,12(12):772-776
Aldosuloses and dialdoses are readily converted to the corresponding acyclic methyloxime trimethylsilyl derivatives which give characteristic mass spectra. The gas chromatography mass spectrometry coupling technique also allows trace analysis since full information can be derived from the most intense fragment ions of the mass spectra which mainly arise from fragmentations β and δ to the O-methyloxime group. 相似文献
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