Time-dependent density functional theory (TDDFT) calculations of electronic circular dichroism (ECD) are widely used to determine absolute configurations (ACs) of chiral molecules. Two very popular DFT exchange-correlation functionals, one hybrid (B3LYP) and one long-range corrected (CAM-B3LYP), along with a hierarchical sequence of basis sets were investigated, and the ECD spectra predicted for eight alkenes and compared to gas-phase experimental spectra. Little variation in predicted ECD spectra was found with the basis set size enlargement, but the sensitivity to the functional is greater. Good agreement was obtained only with the CAM-B3LYP functional, leading to the conclusion that TDDFT calculations of ECD spectra can routinely provide reliable ACs if and only if an appropriate functional is used. For camphene, twistene, syn-(E)-bisfenchylidene, and phyllocladene, solvent effects were estimated.
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http://dx.doi.org/10.1002/chir.22384 | DOI Listing |
J Adv Res
January 2025
State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Avenida da Universidade, Taipa, Macao 999078, China; Guangdong-Hong Kong-Macau Join Laboratory for Pharmacodynamic Constituents of TCM and New Drugs Research, University of Macau, Avenida da Universidade, Taipa, Macao 999078, China; Department of Pharmaceutical Sciences and Technology, Faculty of Health Sciences, University of Macau, Avenida de Universidade, Taipa, Macao 999078, China. Electronic address:
Introduction: Non-alcoholic fatty liver disease (NAFLD) acts as the primary contributor to non-alcoholic steatohepatitis, fibrosis, cirrhosis, and potentially hepatocellular carcinoma. The flowers of Chrysanthemum indicum, a traditional edible medicinal herb, have been widely used in China for more than 2000 years. However, the function of C.
View Article and Find Full Text PDFFitoterapia
January 2025
Institute of Microbial Pharmaceuticals, College of Life and Health Sciences, Northeastern University, Shenyang 110819, China; Key Laboratory of Bioresource Research and Development of Liaoning Province, College of Life and Health Sciences, Northeastern University, Shenyang 110819, China. Electronic address:
Fifteen new aliphatic metabolites, 2-methylpyrimidin-4(3H)-ones (1,2), 2-methoxy-2-methyl-1,2-dihydro-3H-pyrrol-3-ones (4a/4b, 5a/5b), butyrolactones (6-9), and aliphatic metabolites (16-20) as well as known pyridin-2(1H)-one (3) and butyrolactone analogues (10-15) were obtained from the fermentation broth of Streptomyces antifungus isolated from the forest soil sample collected in Tengchong, China. Pyrimidin-4(3H)-one derivatives (1, 2) with an individual 2-methylpyrimidin-4(3H)-one skeleton is a kind of rarely reported compound and were firstly obtained from natural source. The structures of the new metabolites were elucidated by comprehensive spectroscopic analysis including data from experimental and calculated ECD spectra as well as Mosher's reagent derivative method.
View Article and Find Full Text PDFSci Rep
January 2025
Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, Poznan, 61 614, Poland.
The embellishing of the macrocycle core with sulfur substituents of varied sterical requirements changes the structural dynamics of chiral, triangular polyimines. Despite their formal high symmetry, these compounds adopt diverse conformations, in which the macrocycle core represents a non-changeable unit. DFT calculations reveal that the mutual arrangement of sulfur-containing substituents is controlled mainly by sterical interactions.
View Article and Find Full Text PDFPhytochemistry
January 2025
School of Pharmacy, Henan University of Chinese Medicine, Zhengzhou, 450046, PR China; The Engineering and Technology Center for Chinese Medicine Development of Henan Province, Zhengzhou, 450046, PR China; Collaborative Innovation Center for Chinese Medicine and Respiratory Diseases By Henan Province and Ministry of Education of China, Zhengzhou, 450046, PR China. Electronic address:
From the tuber of Alisma orientale (Sam.) Juzep. (Alismataceae), twenty-four compounds were isolated, including six (1, 2, 3, 10, 14, and 17) that were not yet characterized.
View Article and Find Full Text PDFNat Comput Sci
January 2025
AI for Science (AI4S)-Preferred Program, Peking University Shenzhen Graduate School, Shenzhen, China.
Electronic circular dichroism (ECD) spectra contain key information about molecular chirality by discriminating the absolute configurations of chiral molecules, which is crucial in asymmetric organic synthesis and the drug industry. However, existing predictive approaches lack the consideration of ECD spectra owing to the data scarcity and the limited interpretability to achieve trustworthy prediction. Here we establish a large-scale dataset for chiral molecular ECD spectra and propose ECDFormer for accurate and interpretable ECD spectrum prediction.
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