排序方式: 共有72条查询结果,搜索用时 15 毫秒
1.
Zhang Guanshi Zhang Jialing DeHoog Rachel J. Pennathur Subramaniam Anderton Christopher R. Venkatachalam Manjeri A. Alexandrov Theodore Eberlin Livia S. Sharma Kumar 《Metabolomics : Official journal of the Metabolomic Society》2020,16(1):1-12
Metabolomics - Food and dietary ingredients have significant effects on metabolism and health. To evaluate whether and how different diets affected the serum lipidomic profile of dogs. Sixteen... 相似文献
2.
Rioli V Gozzo FC Heimann AS Linardi A Krieger JE Shida CS Almeida PC Hyslop S Eberlin MN Ferro ES 《The Journal of biological chemistry》2003,278(10):8547-8555
Endopeptidase 24.15 (EC; ep24.15), neurolysin (EC; ep24.16), and angiotensin-converting enzyme (EC; ACE) are metallopeptidases involved in neuropeptide metabolism in vertebrates. Using catalytically inactive forms of ep24.15 and ep24.16, we have identified new peptide substrates for these enzymes. The enzymatic activity of ep24.15 and ep24.16 was inactivated by site-directed mutagenesis of amino acid residues within their conserved HEXXH motifs, without disturbing their secondary structure or peptide binding ability, as shown by circular dichroism and binding assays. Fifteen of the peptides isolated were sequenced by electrospray ionization tandem mass spectrometry and shared homology with fragments of intracellular proteins such as hemoglobin. Three of these peptides (PVNFKFLSH, VVYPWTQRY, and LVVYPWTQRY) were synthesized and shown to interact with ep24.15, ep24.16, and ACE, with K(i) values ranging from 1.86 to 27.76 microm. The hemoglobin alpha-chain fragment PVNFKFLSH, which we have named hemopressin, produced dose-dependent hypotension in anesthetized rats, starting at 0.001 microg/kg. The hypotensive effect of the peptide was potentiated by enalapril only at the lowest peptide dose. These results suggest a role for hemopressin as a vasoactive substance in vivo. The identification of these putative intracellular substrates for ep24.15 and ep24.16 is an important step toward the elucidation of the role of these enzymes within cells. 相似文献
3.
Moreira MF Dos Santos AS Marotta HR Mansur JF Ramos IB Machado EA Souza GH Eberlin MN Kaiser CR Kramer KJ Muthukrishnan S Vasconcellos AM 《Insect biochemistry and molecular biology》2007,37(12):1249-1261
An insoluble white substance was prepared from extracts of eggshells of Aedes aegypti, the yellow fever mosquito and dengue vector. Its infrared and proton NMR spectra were similar to that of standard commercial chitin. This putative chitin-like material, also obtained from ovaries, newly laid and dark eggs, was hydrolyzed in acid and a major product was identified by HPLC to be glucosamine. The eggshell acid hydrolysate was also analyzed by ESI-MS and an ion identical to a glucosamine monoprotonated species was detected. The presence of chitin was also analyzed during different developmental stages of the ovary using a fluorescent microscopy technique and probes specific for chitin. The results showed that a chitin-like material accumulates in oocytes during oogenesis. Streptomyces griseus chitinase pre-treatment of oocytes greatly reduced the chitin-derived fluorescence. Chitinase activity was detected in newborn larvae and eggs prior to hatching. Feeding experiments indicated that the chitin synthesis inhibitor lufenuron inhibited chitin synthesis, either when mosquitoes were allowed to feed directly on lufenuron-treated chickens or when an artificial feeding system was used. Lufenuron inhibited egg hatch, larval development and reduced mosquito viability. These data demonstrate for the first time that (1) a chitin-like material is present in A. aegypti eggs, ovaries and eggshells; (2) a chitin synthesis inhibitor can be used to inhibit mosquito oogenesis; and (3) chitin synthesis inhibitors have potential for controlling mosquito populations. 相似文献
4.
5.
6.
Daniela M. Tomazela Gunter Ebeling Marcos N. Eberlin Jairton Dupont 《Inorganica chimica acta》2004,357(8):2349-2357
Electrospray (ESI) mass spectra analysis of acetonitrile solutions of a series of neutral chloro dimers, pincer type, and monomeric palladacycles has enabled the detection of several of their derived ionic species. The monometallic cationic complexes Pd[κ1-C,κ1-N,κ1-S-C(CH3S-2-C6H4)C(Cl)CH2N(CH3)2]+ (1a) and [Pd[κ1-C,κ1-N,κ1-S-C(CH3S-2-C6H4)C(Cl)CH2N(CH3)2](CH3CN)]+ (1b) and the bimetallic cationic complex [κ1-C,κ1-N,κ1-S-C(CH3S-2-C6H4)C(Cl)CH2N(CH3)2]Pd-Cl-Pd[κ1-C,κ1-N,κ1-S-C(CH3S-2-C6H4)C(Cl)CH2N(CH3)2]+ (1c) were detected from an acetonitrile solution of the pincer palladacycles Pd[κ1-C,κ1-N,κ1-S-C(CH3S-2-C6H4)C(Cl)CH2N(CH3)2](Cl) 1. For the dimeric compounds {Pd[κ1-C,κ1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2](μ-Cl)}2 (2, Y=H and 3, CF3), highly electronically unsaturated palladacycles [Pd[κ1-C,κ1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2]+ (2d, 3d) and their mono and di-acetonitrile adducts, namely, [Pd[κ1-C,κ1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2](CH3CN)]+ (2e, 3e) and [Pd[κ1-C,κ1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2](CH3CN)2]+ (2f and 3f) were detected together with the bimetallic complex [Pd[κ1-C,κ1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2]-Cl-Pd[κ1-C,κ1-N-C(Y-2-C6H4)C(Cl)CH2N](CH3)2]+ (2a, 3a) and its acetonitrile adducts [κ1-C,κ1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2](CH3CN)Pd-Cl-Pd[ κ1-C,κ1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2]+ (2b, 3b) and [κ1-C,κ1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2](CH3CN)Pd-Cl-Pd[κ1-C, κ1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2(CH3CN)]+ (2c, 3c). The dimeric palladacycle {Pd[κ1-C,κ1-N-C(CH3O-2-C6H4)C(Cl)CH2N(CH3)2](μ-Cl)}2 (4) is unique as it behaves as a pincer type compound with the OCH3 substituent acting as an intramolecular coordinating group which prevents acetonitrile full coordination, thus forming the cationic complexes [(C6H4(o-CH3O)CC(Cl)CH2N(CH3)2-κO,κC,κN)Pd]+ (4b), [(C6H4(o-CH3O)CC(Cl)CH2N(CH3)2- κO,κC,κN)Pd(CH3CN)]+ (4c) and [(C6H4 (o-MeO)CC(Cl)CH2N(CH3)2-κO, κC,κN)Pd-Cl-Pd(C6H4(o-CH3O)CC(Cl)CH2N(CH3)2-κO,κC,κN)]+ (4a). ESI-MS spectra analysis of acetonitrile solutions of the monomeric palladacycles Pd[κ1-C,κ1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2](Cl)(Py) (5, Y=H and 6, Y=CF3) allows the detection of some of the same species observed in the spectra of the dimeric palladacycles, i.e., monometallic cationic 2d-3d, 2e-3e and {Pd[κ1-C,κ1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2](Py)}+ (5a, 6a) and {Pd[κ1-C,κ1-N-C(Y-2-C6H4)C(Cl)CH2N(CH3)2](CH3CN)(Py)}+ (5b, 6b) and the bimetallic 2a, 3a, 2b, 3b, 2c and 3c. In all cationic complexes detected by ESI-MS, the cyclometallated moiety was intact indicating the high stability of the four or six electron anionic chelate ligands. The anionic (chloride) or neutral (pyridine) ligands are, however, easily replaced by the acetonitrile solvent. 相似文献
7.
Gallardo GL Butler M Gallo ML Rodríguez MA Eberlin MN Cabrera GM 《Phytochemistry》2006,67(21):2403-2410
In a screening for antimicrobial metabolites, amides of D-allo- and L-isoleucine derivatives were isolated from the culture of a marine strain of Acremonium furcatum. Structural elucidation of these compounds was performed by analysis of spectroscopic data and confirmed by synthesis. All of the compounds, natural and synthetic intermediates, were bioassayed against bacteria and phytopathogenic fungi, with many showing remarkable antifungal activities. 相似文献
8.
Silva GH Teles HL Zanardi LM Marx Young MC Eberlin MN Hadad R Pfenning LH Costa-Neto CM Castro-Gamboa I da Silva Bolzani V Araújo AR 《Phytochemistry》2006,67(17):1964-1969
Five cadinane sesquiterpenes derivatives were isolated by bioassay-guided fractionation from Phomopis cassiae, an endophytic fungus isolated from Cassia spectabilis. The structures of the two diastereoisomeric 3,9,12-trihydroxycalamenenes (1, 2); 3,12-dihydroxycalamenene (3); 3,12-dihydroxycadalene (4) and 3,11,12-trihydroxycadalene (5) were established on the basis of analyses of 1D and 2D NMR and HRTOFMS experiments. Antifungal activity of the isolates was evaluated against Cladosporium sphaerospermum and Cladosporium cladosporioides, revealing 5 as the most active compound. 相似文献
9.
10.
Structural and functional characterization of myotoxin, Cr-IV 1, a phospholipase A2 D49 from the venom of the snake Calloselasma rhodostoma 总被引:1,自引:0,他引:1
V.L. Bonfim L.A. Ponce-Soto D. Martins de Souza G.H.M.F. Souza P.A. Baldasso M.N. Eberlin S. Marangoni 《Biologicals》2008,36(3):168-176
A new D49 PLA(2) was purified from the venom of Calloselasma rhodostoma after two chromatographic steps. Molecular exclusion chromatography was done through a Protein-Pack 300 SW column (0.78 cm x 30 cm), eluting with 0.25 M ammonium bicarbonate, pH 7.9, at a flow rate of 0.3 ml/min. Reverse-phase HPLC was then performed on mu-Bondapack C-18. The sample was determined to have a molecular mass of 13,870.94 Da MALDI-TOF by mass spectrometry, and the amino acid composition showed that Cr-IV 1 presented a high content of Lys, Tyr, Gly, Pro, and 14 half-Cys residues, typical of a basic PLA(2). Cr-IV 1 presented a sequence of 122 amino acid residues: DLWEFGQMILKETGSLPFPY YTTYGCYCGV GGRGGKPKDA TDRCCFVHDC CYGKLTGCPK TNDRYSYSRL DYTIVCGEGG PCKQICECDK AAAVCFRENL RTYNKKYRYHLKPFCKEPAE TC and a calculated pI value of 8.0. Cr-IV 1 had PLA(2) activity in the presence of a synthetic chromogenic substrate (4-nitro-3-(octanoyloxy)benzoic acid) and showed a rapid cytolytic effect on mouse skeletal muscle myoblasts and myotubes in culture. In mice, Cr-IV 1 induced myonecrosis and edema upon intramuscular and intravenous injections, respectively. The LD(50) of Cr-IV 1 was determined to be 0.07 mg/k body weight by intracerebroventricular (i.c.v.) injection. The combination of structural and functional information obtained herein classifies Cr-IV 1 as a new member of the D49 PLA(2) family, as it presents the typical behavior of a phospholipase A(2) from this family. 相似文献