scholarly journals Unveiling the formation 1 : 2 supramolecular complexes between cucurbit[7]uril and a cationic calix[4]arene derivative

2019 ◽  
Vol 55 (92) ◽  
pp. 13828-13831 ◽  
Author(s):  
Márcia Pessêgo ◽  
Johan Mendoza ◽  
José Paulo da Silva ◽  
Nuno Basílio ◽  
Luis Garcia-Rio
Keyword(s):  
Isothermal Titration Calorimetry ◽  
Supramolecular Complexes ◽  
Titration Calorimetry ◽  
Cone Conformation ◽  
Arene Derivative ◽  
Esi Ms ◽  
H Nmr ◽  
Dosy Nmr

The formation of host–guest complexes between cucurbit[7]uril (CB7) and a tetracationic calix[4]arene derivative in the so-called cone conformation was investigated by 1H NMR, DOSY NMR, isothermal titration calorimetry and ESI-MS.

scholarly journals Study of the host–guest interaction between N,N′-bis[4-(dimethylaminophenyl)methyl]butane-1,4-diamine and the cucuribit[n]urils (n = 6, 7)

2019 ◽  
Vol 43 (37) ◽  
pp. 14938-14943 ◽  
Author(s):  
Zhiyou Xiao ◽  
Yang Zhou ◽  
Weitao Xu ◽  
Timothy J. Prior ◽  
Bing Bian ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Isothermal Titration Calorimetry ◽  
Absorption Spectroscopy ◽  
Electronic Absorption ◽  
Electronic Absorption Spectroscopy ◽  
Titration Calorimetry ◽  
H Nmr

Interaction of the cucuribit[n]urils (n = 6 or 7) and the guest N,N′-bis[4-(dimethylaminophenyl)methyl]butane-1,4-diamine (G) has been studied in aqueous solution by 1H NMR and electronic absorption spectroscopy and Isothermal Titration Calorimetry.

Enantioselective Recognition of Chiral Guests by the Water-Soluble Chiral Keplerate {Mo132} Spherical Capsule with 30 Inner Lactate Ligands

2019 ◽  
Author(s):  
Nancy Watfa ◽  
Weimin Xuan ◽  
Zoe Sinclair ◽  
Robert Pow ◽  
Yousef Abul-Haija ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Chiral Recognition ◽  
Association Constants ◽  
Water Soluble ◽  
Enantioselective Recognition ◽  
H Nmr ◽  
Dosy Nmr ◽  
Spherical Capsule ◽  
Surface Pores ◽  
Guest Chemistry

Investigations of chiral host guest chemistry are important to explore recognition in confined environments. Here, by synthesizing water-soluble chiral porous nanocapsule based on the inorganic metal-oxo Keplerate-type cluster, {Mo<sub>132</sub>} with chiral lactate ligands with the composition [Mo<sub>132</sub>O<sub>372</sub>(H<sub>2</sub>O)<sub>72</sub>(<i>x-</i>Lactate)<sub>30</sub>]<sup>42-</sup> (<i>x</i> = D or L), it was possible to study the interaction with a chiral guest, L/D-carnitine and (<i>R</i>/<i>S</i>)-2-butanol in aqueous solution. The enantioselective recognition was studied by quantitative <sup>1</sup>H NMR and <sup>1</sup>H DOSY NMR which highlighted that the chiral recognition is regulated by two distinct sites. Differences in the association constants (K) of L- and D-carnitine, which, due to their charge, are generally restricted from entering the interior of the host, are observed, indicating that their recognition predominantly occurs at the surface pores of the structure. Conversely, a larger difference in association constants (K<i><sub>S</sub></i>/K<i><sub>R</sub></i> = 3) is observed for recognition within the capsule interior of (<i>R</i>)- and (<i>S</i>)-2-butanol.

Effects of Saccharomyces Cerevisiae Strains on Chemical Profiles of Cabernet Sauvignon Wines: Based on the Combined Results of 1H NMR, HS-SPME/GC-MS and HPLC-DAD-ESI-MS/MS

2018 ◽  
Vol 18 (2) ◽  
pp. 115-131
Author(s):  
Liang Heng-Yu ◽  
Su Ning ◽  
Guo Kun ◽  
Wang Yuan ◽  
Yang De-Yu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Principal Component ◽  
Grape Juice ◽  
Pilot Scale ◽  
Ethyl Esters ◽  
Cabernet Sauvignon ◽  
Esi Ms ◽  
H Nmr ◽  
Chemical Profiles ◽  
Indigenous Yeasts

Five Saccharomyces cerevisiae strains (Chinese indigenous yeasts SC5, WC5, SC8, CC17 and commercial starter F15) were inoculated into Cabernet sauvignon grape must and fermented at pilot scale. For the first time, combination of 1H NMR, HS-SPME/GC-MS and HPLC-DAD-ESI-MS/MS metabonomic profiling techniques was performed to analyze the global chemical fingerprints of sampled wines at the end of alcoholic and malolactic fermentation respectively, then 13 non-volatile flavor compounds, 52 volatile organic aromas and 43 polyphenolic molecules were identified and determined correspondently. All principal component analysis (PCA) of two fermentation stages based on the analytical results of 1H NMR, HS-SPME/GC-MS and HPLC-DAD-ESI-MS/MS divided these strains into three clusters: (1) SC5 and SC8, (2) WC5 and F15 and (3) CC17. The wine fermented by indigenous yeast, CC17, showed a very unique chemical profile, such as low pH and high color intensity, reduced amino acids (including proline) and the lowest total higher alcohols levels, most of the fixed acids, glycerol, ethyl esters and anthocyanins concentrations. The statistical results indicate that CC17 strain possesses very special anabolism and catabolism abilities on such substances in grape juice and has potentiality to produce characteristic wines with high qualities.

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