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The exceptional case of a natural compound that shows drastic absolute configuration variations within the same species was examined. Sequential samples of areolal () isolated from showed dextrorotatory (ee 32%), almost racemic (ee 4%), levorotatory (ee 82%), and again dextrorotatory (ee 10%) values. Enantiomeric compositions of this epoxythymol derivative were determined from individual plant specimens collected from the same geographical location over a 46-day period, which were processed using the same extraction and isolation methods. Detection of this unusual phenomenon was possible by analysis of NMR data recorded in the presence of BINOL as a chiral solvating agent. The absolute configuration of (-)-(8)-areolal followed from vibrational circular dichroism data of an enantiomerically enriched sample, while single-crystal X-ray diffraction and supramolecular analyses revealed interactions that diminish the crystal entropy in -. These results might be related with environmental factors and biochemical processes, suggesting the need of strict evaluations of enantiomeric composition of natural products that could be considered for human applications.
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http://dx.doi.org/10.1021/acs.jnatprod.9b00734 | DOI Listing |
Nat Aging
September 2025
Department of Clinical Molecular Biology, University of Oslo and Akershus University Hospital, Lørenskog, Norway.
Beyond their classical functions as redox cofactors, recent fundamental and clinical research has expanded our understanding of the diverse roles of nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP) in signaling pathways, epigenetic regulation and energy homeostasis. Moreover, NAD and NADP influence numerous diseases as well as the processes of aging, and are emerging as targets for clinical intervention. Here, we summarize safety, bioavailability and efficacy data from NAD-related clinical trials, focusing on aging and neurodegenerative diseases.
View Article and Find Full Text PDFEMBO Mol Med
September 2025
Institute for Regenerative Medicine, Medical Innovation Center and State Key Laboratory of Cardiovascular Diseases, Shanghai East Hospital, National Stem Cell Translational Resource Center & Ministry of Education Stem Cell Resource Center, Frontier Science Center for Stem Cell Research, School of Li
Primary microcephaly, a rare congenital condition characterized by reduced brain size, occurs due to impaired neurogenesis during brain development. Through whole-exome sequencing, we identified compound heterozygous loss-of-function mutations in CENTRIN 3 (CETN3) in a 5-year-old patient with primary microcephaly. As CETN3 has not been previously linked to microcephaly, we investigated its potential function in neurodevelopment in human pluripotent stem cell-derived cerebral organoids.
View Article and Find Full Text PDFNat Biomed Eng
September 2025
Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA.
Phenotype-driven approaches identify disease-counteracting compounds by analysing the phenotypic signatures that distinguish diseased from healthy states. Here we introduce PDGrapher, a causally inspired graph neural network model that predicts combinatorial perturbagens (sets of therapeutic targets) capable of reversing disease phenotypes. Unlike methods that learn how perturbations alter phenotypes, PDGrapher solves the inverse problem and predicts the perturbagens needed to achieve a desired response by embedding disease cell states into networks, learning a latent representation of these states, and identifying optimal combinatorial perturbations.
View Article and Find Full Text PDFRisk Anal
September 2025
School of Public Policy and Administration, Chongqing University, Chongqing, China.
Climate change is causing a significant increase in the number of compound extreme events that pose significantly greater threats to public safety. Chongqing is a megacity in southwestern China that took the brunt of temporally compounding events (TCEs) in the summer of 2022. We developed an approach based on the Intergovernmental Panel on Climate Change (IPCC) risk framework to assess the public health risks posed by TCEs.
View Article and Find Full Text PDFPhytochemistry
September 2025
State Key Laboratory of Phytochemistry and Natural Medicines, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China; Yunnan Characteristic Plant Extraction Laboratory Co. Ltd, Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Educa
Alstoniaschines A‒I (1‒9), nine previously alkaloids sharing five different skeletons were obtained from the leaves of Alstonia scholaris. The structures and absolute configurations were established by their extensive spectroscopic data analyses, including NMR, HRESIMS, X-ray crystallography data, and theoretical ECD calculations. Compounds 1, 2, 3, and 9 exerted significant protective effect against oxidative stress and inflammatory damage of podocytes induced by high glucose, manifesting as the increase of superoxide dismutase, catalase, glutathione peroxidase, alongside the reductions of malondialdehyde, nitric oxide, lactate dehydrogenase.
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