Structural characterization of the molten globule and native states of ovalbumin: A H NMR study

2009 ◽  
Vol 50 (6) ◽  
pp. 465-474 ◽  
Author(s):  
MASARU SOGAMI ◽  
SEIICHI ERA ◽  
TAIHEI KOSEKI ◽  
NAOKI NAGAI
2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Chuanjiang Li ◽  
Hui Wang ◽  
Manuel Juárez ◽  
Eric Dongliang Ruan

Maillard reaction is a nonenzymatic reaction between reducing sugars and free amino acid moieties, which is known as one of the most important modifications in food science. It is essential to characterize the structure of Amadori rearrangement products (ARPs) formed in the early stage of Maillard reaction. In the present study, the Nα-acetyl-lysine-glucose model had been successfully set up to produce ARP, Nα-acetyl-lysine-glucose. After HPLC purification, ARP had been identified by ESI-MS with intense [M+H]+ ion at 351 m/z and the purity of ARP was confirmed to be over 90% by the relative intensity of [M+H]+ ion. Further structural characterization of the ARP was accomplished by using nuclear magnetic resonance (NMR) spectroscopy, including 1D 1H NMR and 13C NMR, the distortionless enhancement by polarization transfer (DEPT-135) and 2D 1H-1H and 13C-1H correlation spectroscopy (COSY) and 2D nuclear overhauser enhancement spectroscopy (NOESY). The complexity of 1D 1H NMR and 13C NMR was observed due to the presence of isomers in glucose moiety of ARP. However, DEPT-135 and 2D NMR techniques provided more structural information to assign the 1H and 13C resonances of ARP. 2D NOESY had successfully confirmed the glycosylated site between 10-N in Nα-acetyl-lysine and 7′-C in glucose.


Biochemistry ◽  
2005 ◽  
Vol 44 (20) ◽  
pp. 7490-7496 ◽  
Author(s):  
Yeoun Jin Kim ◽  
Young A Kim ◽  
Nokyoung Park ◽  
Hyeon S. Son ◽  
Kwang S. Kim ◽  
...  

1993 ◽  
Vol 71 (3) ◽  
pp. 377-383 ◽  
Author(s):  
Monique Fréchette

We have investigated the reaction between La(NO3)3•6H2O and 2,2′-bipyridine (bipy) in acetonitrile by means of 139La, 17O, 13C, and 1H NMR spectroscopy. The 139La spectra show up to three different sites with variable intensities attributed to solvated La(III) ions and to two complex species with one or two bipy moieties in the La(III) coordination sphere. 17O NMR indicates that during the complexation reaction, the coordinated water is totally displaced from the coordination sphere whereas the nitrate groups remain coordinated. Proton NMR data confirm the water expulsion. In addition, the proton chemical shifts of bipy, in comparison with the 13C NMR data, clearly show an anisotropic shielding when two bipy are coordinated to La(III). Therefore, the two bipy molecules are in close proximity in the coordination sphere. From the NMR results it has been shown that, during the complexation process, five different La(III) species are formed: [La(NO3)3(CH3CN)4], [La(NO3)3(CH3CN)3(H2O)], [La(NO3)3(bipy)(CH3CN)2], [La(NO3)3(bipy)(CH3CN)-(H2O)], and [La(NO3)3(bipy)2]. Each La(III) complex has a coordination member of 10, with NO3− and bipy acting as chelating ligands. Furthermore, the structure of the La(NO3)3(bipy)2 complex in solution shows similarities with the solid state compound. Finally, comparisons are made with the La(III) complexes previously obtained with 1,10-phenanthroline.


2019 ◽  
Vol 28 (5) ◽  
pp. 952-963 ◽  
Author(s):  
Amrita Roy ◽  
Sun Qingxiang ◽  
Chapeaurouge Alex ◽  
Nandhakishore Rajagopalan ◽  
Chacko Jobichen ◽  
...  

1995 ◽  
Vol 249 (1) ◽  
pp. 215-228 ◽  
Author(s):  
Mikio Kataoka ◽  
Ichiro Nishii ◽  
Tetsuro Fujisawa ◽  
Tatzuo Ueki ◽  
Fumio Tokunaga ◽  
...  

Author(s):  
Pham Thu Thuy ◽  
Pham Chien Thang ◽  
Nguyen Viet Ha ◽  
Trieu Thi Nguyet

The curcumin derivative 4’,4’’-dibenzoylcurcumin (HL) was synthesized by the reaction between curcumin and benzoyl chloride in the presence of pyridine as a supporting base. The composition and structure of HL were characterized by spectroscopic methods such as IR, 1H and 13C NMR spectroscopy. Reactions of HL and transition metal ions, such as Fe3+ and Cu2+, in mixtures of CH3OH and CH2Cl2 gave rise to the corresponding complexes, compositions and structural features of which were studied by thermal analysis and IR spectroscopy. The results strongly suggested the obtained complexes with the compositions of [FeL3] and [CuL2]. In such compounds, metal ions coordinates with the deprotonated ligands L– through the donor sets (O,O) of the keto-enol moieties. Keywords: Curcumin, 4’,4’’-dibenzoylcurcumin, β-diketone, Fe(III) complexes, Cu(II) complexes. References [1] A. Goel, A.B. Kannumakkara, B.B. Aggarwal, Curcumin as “Curecumin”: From Kitchen to Clinic, Biochem. Pharmacol. 75 (2008) 787-809. https://doi.org/10.1016/j.bcp.2007.08.016.[2] T. Esatbeyoglu, P. Huebbe, I.M.A. Ernst, D. Chin, A.E. Wagner, G. Rimbach, Curcumin - From Molecule to Biological Function, Angew. Chem. Int. Ed. 51 (2012) 5308-5332. https://doi.org/ 10.1002/anie.201107724.[3] K. Priyadarsini, The Chemistry of Curcumin: From Extraction to Therapeutic Agent, Molecules 19 (2014) 20091-20112. https://doi.org/10.3390/ molecules191220091.[4] S. Wanninger, V. Lorenz, A. Subhan, F.T. Edelmann, Metal complexes of curcumin – synthetic strategies, structures and medicinal applications, Chem. Soc. Rev. 44 (2015) 4986-5002. https://doi.org/10.1039/C5CS00088B.[5] J. Wang, D. Wei, B. Jiang, T. Liu, J. Ni, S. Zhou, Two copper(II) complexes of curcumin derivatives: synthesis, crystal structure and in vitro antitumor activity, Transition Met. Chem. 39 (2014) 553-558. https://doi.org/10.1007/s11243-014-9831-z.[6] R. Pettinari, F. Marchetti, C. Pettinari, F. Condello, A. Petrini, R. Scopelliti, T. Riedel, P.J. Dyson, Organometallic rhodium(III) and iridium(III) cyclopentadienyl complexes with curcumin and bisdemethoxycurcumin co-ligands, Dalton Transactions 44 (2015) 20523-20531. https://doi.org/10.1039/C5DT03037D.[7] P.T. Thùy, P.C. Thắng, N.H. Huy, N.V. Hà, T.T. Nguyệt, Synthesis, structural characterization of 4,4’-diacetylcurcumin and its complexes with Fe(III), Co(II) (in Vietnamese), Vietnam Journal of Chemistry 55 (2017) 33-37. [8] P.C. Thắng, P.T. Thùy, T.T.K. Ngân, L.C. Định, Đ.T. Đạt, T.T. Nguyệt, Synthesis, structural characterization of 4’,4’’-dimethoxy-4-methylcurcumin and evaluation of its complexation with Co2+ and Cu2+ (in Vietnamese), Vietnam Journal of Chemistry 56 (2018) 113-117. [9] P.T. Thùy, P.C. Thắng, V.T.B. Ngoc, T.T. Nguyệt, Synthesis and structural characterization of a heteroleptic Pd(II) complex with 4,4’-diacetylcurcumin (in Vietnamese), Vietnam Journal of Chemistry 56 (2018) 119-123. [10] K. Singletary, C. MacDonald, M. Iovinelli, C. Fisher, M. Wallig, Effect of the beta-diketones diferuloylmethane (curcumin) and dibenzoylmethane on rat mammary DNA adducts and tumors induced by 7,12-dimethylbenz[a] anthracene, Carcinogenesis 19 (1998) 1039-1043. https://doi.org/10.1093/carcin/ 19.6.1039.[11] F. Payton, P. Sandusky, W.L. Alworth, NMR Study of the Solution Structure of Curcumin, J. Nat. Prod. 70 (2007) 143-146. https://doi.org/10. 1021/np060263s.  


The Analyst ◽  
2016 ◽  
Vol 141 (18) ◽  
pp. 5390-5397 ◽  
Author(s):  
Benqing Zhou ◽  
Mingwu Shen ◽  
István Bányai ◽  
Xiangyang Shi

The internal spatial structures of PEGylated polyethylenimine-entrapped gold nanoparticles can be effectively analyzed via advanced NMR techniques.


2005 ◽  
Vol 60 (9) ◽  
pp. 945-950 ◽  
Author(s):  
Jorge R. Angulo-Cornejo ◽  
Ketty Ayala-León ◽  
Gabriel García Herbosa ◽  
José V. Cuevas ◽  
Virginia Diez ◽  
...  

The synthesis of N-[4-(2-hydroxyethyl)-1,2,4-oxathiazinan-3-ylidene]-benzamide (2a) and N-[4- (2-hydroxyethyl)-1,2,4-oxathiazinan-3-ylidene]-2-fluorobenzamide (2b) by oxidation of the corresponding 1,1-bis(2-hydroxyethyl)-3-aroylthioureas with potassium iodate in aqueous solution is reported. Variable temperature 1H NMR spectra of 2a prove that the heterocyclic 1,2,4-(O, S,N) sixmembered ring is involved in a dynamic chair-boat conformational interconversion. Molecular mechanic calculations show that the chair conformation is more stable than the boat conformation by 3.0 kcal/mol. The synthesis of the adduct [(2a)·0.5 HgCl2] 3 as well as the X-ray structural characterization of 2a and 3 are also reported.


1994 ◽  
Vol 33 (14) ◽  
pp. 3169-3176 ◽  
Author(s):  
Luisa Schenetti ◽  
Giuliano Bandoli ◽  
Alessandro Dolmella ◽  
Guendalina Trovo ◽  
Bruno Longato

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