An achiral chromophore can acquire a chiral spectroscopic signature when interacting with a chiral environment. This so-called induced chirality is documented in electronic or vibrational circular dichroism, which arises from the coupling between electric and magnetic transition dipoles. Here, we demonstrate that a chiroptical response is also induced within the electric dipole approximation by observing the asymmetric scattering of a photoelectron ejected from an achiral chromophore in interaction with a chiral host. In a phenol-methyloxirane complex, removing an electron from an achiral aromatic π orbital localised on the phenol moiety results in an intense and opposite photoelectron circular dichroism (PECD) for the two enantiomeric complexes with (R) and (S) methyloxirane, evidencing the long-range effect (~5 Å) of the scattering chiral potential. This induced chirality has important structural and analytical implications, discussed here in the context of growing interest in laser-based PECD, for in situ, real time enantiomer determination.
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http://dx.doi.org/10.1038/s41467-023-42002-1 | DOI Listing |
Phytochemistry
January 2025
CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Nanhai Road 7, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Wenhai Road 1, Qingdao 266237, China; University of Chinese Academy of Sciences, Yuquan Road 19A, Beijing 100049, China. Electronic address:
Six previously undescribed spiromeroterpenoids, chermesins I-N (1-6), were isolated and identified from the marine-sourced fungus Penicillium chermesinum AS-400. Their structures were determined by nuclear magnetic resonance and mass spectroscopic data, and the relative and absolute configurations were confirmed based on nuclear Overhauser effect spectroscopic experiments, electronic circular dichroism (ECD) calculations and X-ray crystallographic analysis, and by comparisons of ECD Cotton effects with those of known congeners as well. Structurally, compound 1 represents the first example of spiromeroterpenoid demethylated at C-4.
View Article and Find Full Text PDFBioorg Chem
December 2024
Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, PR China. Electronic address:
Nidustrin A (1), the first cysteine-retained emestrin featuring a unique sulfur-containing 18-membered macrocyclic lactone, along with four biogenetically related compounds (2-5), and one known analogue secoemestrin C (6), were isolated from the large-scale culture of Aspergillus nidulans, an endophytic fungus derived from the Whitmania pigra. Compounds 2 and 3 represent the second examples of noremestrin besides the previously reported noremestrin A, and the single crystal X-ray diffraction analysis of compound 2 provided solid evidence for the intriguing skeleton of noremestrin. Their structures were determined by extensive spectroscopic data, electronic circular dichroism calculations, and single-crystal X-ray diffraction.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Jinan University, State Key Laboratory of Bioactive Molecules and Druggability Assessment, CHINA.
Secupyritines A‒C are unique polycyclic Securinega alkaloids isolated from medicinal plant Flueggea suffruticosa. They feature a distinctive 6/6/6/5/6 fused pentacyclic ring system with a highly strained 2-oxa-6-aza[4.4.
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.
View Article and Find Full Text PDFBioorg Chem
December 2024
Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Medicinal Chemistry, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address:
In this study, novel 2-styrylquinoline derivatives possessing a planar aromatic system and a flexible side chain with an amino substituent were designed and synthesized as DNA-intercalating antitumor agents. The cytotoxic activity of the synthesized compounds was evaluated against four cancer cell lines including MCF-7 (breast cancer cells), A549 (lung epithelial cancer cells), HCT116 (colon cancer cells) and normal cell line L929 (mouse fibroblast cell line). The results displayed that the anti-cancer activity of the target quinolines is sensitive to the lipophilic nature of the C-6 and C-7 quinoline substituents.
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