We describe here the effects of metal complexation on the molecular recognition behavior of cavitands with quinoxaline walls. The nitrogen atoms of the quinoxalines are near the upper rim of the vase-like shape and treatment with Pd(II) gave 2:1 metal:cavitand derivatives. Characterization by H, C NMR spectroscopy, HR ESI-MS, and computations showed that the metals bridged adjacent quinoxaline panels and gave cavitands with C symmetry. Both water-soluble and organic-soluble versions were prepared and their host/guest complexes with alkanes, alcohols, acids, and diols (up to C12) were studied by H NMR spectroscopy. Analysis of the binding behavior indicated that the metals rigidified the walls of the receptive vase conformation and enhanced the binding of hydrophobic and even water-soluble guests, compared to related cavitands reported previously. The results demonstrated that the conformational dynamics of the cavitand were slowed by the coordination of Pd(II) and stabilized the host's complexes.
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http://dx.doi.org/10.1073/pnas.1909154116 | DOI Listing |
Chemistry
January 2025
University of Leipzig, Physics and Geoscience, Linnestr. 5, 4103, Leipzig, GERMANY.
The development of smart materials capable of separating dihydrogen isotopologues has risen recently. Among potential candidates, the flexible MIL-53 (Al) has been gaining attention due to its structural flexibility providing the so-called ''breathing mechanism'' that can be useful to separate hydrogen isotopologues selectively. In the present work, an in situ continuous wave electron paramagnetic resonance investigation has been proven as a sensitive technique to follow the isotopologue-selective adsorption-desorption of dihydrogen species on the paramagnetic metal-doped MIL-53 (Al0.
View Article and Find Full Text PDFEur Child Adolesc Psychiatry
January 2025
National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance Spectroscopy and Imaging, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, 430071, China.
Emerging evidence suggests aberrant functional connectivity (FC) of brain networks in children, adolescents, and adults with autism spectrum disorder (ASD). However, little is known about alterations of dynamic FC in toddlers with ASD. The aim of this study was to investigate the characteristics of brain network dynamics in ASD toddlers.
View Article and Find Full Text PDFToxics
December 2024
Department of Biological and Environmental Science and Technology (Di.S.Te.B.A.), University of Salento, Campus Ecotekne, Via Prov. Lecce-Monteroni, 73100 Lecce, Italy.
The various forms of anthropogenic pollution are regarded as a serious threat to marine coastal areas. The overproduction and mismanagement of petroleum derivatives, such as tar and plastics, have resulted in a significant correlation between these two pollutants. The aggregation of tar, microplastics (MPs), and natural materials can create plastitar blocks, which are common in coastal areas.
View Article and Find Full Text PDFTomography
January 2025
NextGen Precision Health, Department of Radiology, University of Missouri Columbia, 1030 Hitt Street, Columbia, MO 65201, USA.
: The increased SNR available at 7T combined with fast readout trajectories enables accelerated spectroscopic imaging acquisitions for clinical applications. In this report, we evaluate the performance of a Hadamard slice encoding strategy with a 2D rosette trajectory for multi-slice fast spectroscopic imaging at 7T. : Moderate-TE (~40 ms) spin echo and J-refocused polarization transfer sequences were acquired with simultaneous Hadamard multi-slice excitations and rosette in-plane encoding.
View Article and Find Full Text PDFMar Drugs
January 2025
Department of Chemistry, University of South Florida, 4202 E. Fowler Avenue, CHE205, Tampa, FL 33620, USA.
New technology has opened opportunities for research and exploration of deep-water ecosystems, highlighting deep-sea coral reefs as a rich source of novel bioactive natural products. During our ongoing investigation of the chemodiversity of the Irish deep sea and the soft coral we report 12 unreported cadinene-like functionalized sesquiterpenes, anthoteibinenes F-Q. The metabolites were isolated using both bioassay- and H NMR-guided approaches.
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