H and C nuclear magnetic resonance (NMR) chemical shifts of a tetrakis monoterpene indole alkaloid alasmontamine A with a molecular formula of C H N O have been calculated at the PBE0/pcSseg-2//pcseg-2 level of theory on M06-2X/aug-cc-pVDZ geometry. In the course of the preliminary conformational search, six true minimum energy conformers were identified that can contribute to the actual conformation of this huge alkaloid. Calculated chemical shifts generally demonstrated a good agreement with available experimental data characterized with a corrected mean absolute error of 0.10 ppm for the range of about 7 ppm for protons and 1.1 ppm for the range of about 160 ppm for carbons.
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http://dx.doi.org/10.1002/mrc.5256 | DOI Listing |
Nat Commun
January 2025
School of Environmental and Chemical Engineering, Wuyi University, Jiangmen, PR China.
Developing efficient strategies for the deoxygenative functionalization of carbonyl compounds is crucial for enhancing the effective utilization of biomass and the upgrading of chemical feedstocks. In this study, we present an elegant cathodic reduction strategy that enables a tandem alkylation/dearomatization reaction between quinoline derivatives and aryl aldehydes/ketones in a one-pot process. Our approach can be executed via two distinct paths: the aluminum (Al)-facilitated spin-center shift (SCS) path and the Al-facilitated direct deoxygenation path.
View Article and Find Full Text PDFBioresour Technol
January 2025
University of Zagreb Faculty of Chemical Engineering and Technology, Marulićev trg 19, HR-10000 Zagreb, Croatia. Electronic address:
Efforts to reduce the impact of chemical processes on the environment are leading to a shift to enzymatic alternatives, with laccases standing out for their versatile substrate oxidation capabilities. This study addresses the improvement of biocatalytic reactions by deep eutectic solvents (DES), in particular DES-based aqueous two-phase systems (ATPS) for the extraction of biomolecules. Continuous laccase extraction from crude samples was achieved using a DES-based ATPS, which was first optimized in a batch extractor and later intensified in a microextractor.
View Article and Find Full Text PDFStem Cells
January 2025
Bioengineering Graduate Program, University of Notre Dame, Notre Dame, 46556 IN, USA.
Myocardial infarction can lead to the loss of billions of cardiomyocytes, and while cell-based therapies are an option, immature nature of in vitro-generated human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iCMs) is a roadblock to their development. Existing iPSC differentiation protocols don't go beyond producing fetal iCMs. Recently, adult extracellular matrix (ECM) was shown to retain tissue memory and have some success driving tissue-specific differentiation in unspecified cells in various organ systems.
View Article and Find Full Text PDFJ Cereb Blood Flow Metab
January 2025
Department of Neurology and Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, Tennessee, USA.
Current metabolomics technologies can measure hundreds of chemical entities in tissue extracts with good reliability. However, long-recognized requirements to halt enzyme activities during the initial moments of sample preparation are usually overlooked, allowing marked postmortem shifts in levels of labile metabolites representing diverse pathways. In brain many such changes occur in a matter of seconds.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
State Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum (Beijing), Beijing 102249, China.
The Bohai oilfield is characterized by severe heterogeneity and high average permeability, leading to a low water flooding recovery efficiency. Polymer flooding only works for a certain heterogeneous reservoir. Therefore, supplementary technologies for further enlarging the swept volume are still necessary.
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