7-epi-sesquithujene (1) is a bicyclic sesquiterpene isolated from phoebe oil, an essential oil of the Brazilian walnut tree, Phoebe porosa. It is also produced by stressed ash trees and has been shown to elicit strong electrophysiological responses on emerald ash borer, Agrilus planipennis, antennae. In the course of the development of a synthetic 7-epi-sesquithujene lure for field testing against the emerald ash borer, we found that the absolute configuration of this compound had not been determined. We isolated >95% pure 7-epi-sesquithujene from phoebe oil via successive fractionation and conventional and argentation (HPLC) chromatographies. The specific optical rotation of this compound matched that of a synthetic product of known configuration. We also synthesized two other stereoisomers of sesquithujene and developed a chiral GC method to separate all four. Based on the specific rotation, stereoselective syntheses, and chiral GC analyses, 7-epi-sesquithujene present in phoebe oil and white ash was found to have the 2S,6S,7R absolute configuration.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/np200098z | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Chiroptical spectroscopy complemented by quantum chemical calculations accurately predicts the absolute configuration of P-chirogenic compounds.
Spectrochim Acta A Mol Biomol Spectrosc
January 2025
Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 160 00 Prague, Czech Republic. Electronic address:
Model P-chirogenic phosphonates derived from isopinocampheol, offering an excellent experimental system for studying chirality on the phosphorus chiral center, were studied using a set of chiroptical methods including ECD, VCD and ROA. Thanks to their rigidity, limiting the number of possible conformers, we successfully correlated the experimental UV-vis/ECD, IR/VCD and Raman/ROA results with DFT calculations. This allowed us to confidently assign the absolute configuration of our models, and our assignment is consistent with X-ray diffraction (XRD) data.
View Article and Find Full Text PDFSmoking Cessation Interventions in the Lung Cancer Screening Setting: A Randomized Clinical Trial.
JAMA Intern Med
January 2025
Department of Behavioral Science, The University of Texas MD Anderson Cancer Center, Houston.
Importance: The optimal configuration of a smoking cessation intervention in a lung cancer screening (LCS) setting has not yet been established.
Objective: To evaluate the efficacy of 3 tobacco treatment strategies of increasing integration and intensity in the LCS setting.
Design, Setting, And Participants: In this randomized clinical trial, LCS-eligible current smokers were randomized into 3 treatments: quitline (QL), QL plus (QL+), or integrated care (IC).
Discovery of potent antiosteoporotic cyclic depsipeptides with an unusual nitrile hydroxy acid from Microascus croci.
Bioorg Chem
January 2025
National Center for Screening New Microbial Drugs, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, PR China. Electronic address:
Two cyclic octadepsipeptides, microascusins A and B (1 and 2), were identified from the marine sponge-associated Microascus croci IMB19-064 co-cultivated with Escherichia coli. Their structures and conformations in solution were determined by comprehensive spectroscopic data analysis. The absolute configurations of amino and hydroxy acids were determined by the advanced Marfey's and O-Marfey's methods, respectively, as well as chiral-phase HPLC analysis.
View Article and Find Full Text PDFTerpenes from and the evaluation of their potential anti-inflammatory activity.
Nat Prod Res
January 2025
Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Characteristic Plant Extraction Laboratory, Yunnan Key Laboratory of Research and Development for Natural Products, State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, School of Medicine, School of Pharmacy and School of Chemical Science and Technology, Yunnan University, Kunming, P. R. China.
Two undescribed compounds, including one monoterpene () and one sesquiterpene (), together with eleven known compounds were isolated from . The structures of the isolated compounds were determined by comprehensive spectroscopic analysis; the absolute configurations of these compounds were determined by ECD calculation. Some of the compounds were tested for anti-inflammatory activity.
View Article and Find Full Text PDFNeuroprotective Indole Alkaloids from the Soil-Derived Fungus sp. XZ8.
J Nat Prod
January 2025
Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry and Pharmacy, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China.
A chemical investigation of the soil-derived fungus sp. XZ8 led to the isolation of five new indole alkaloids, trichindoles A-E (-), with diverse architectures, along with seven known analogues (-). Their structures were elucidated by extensive spectroscopic data analysis, and their absolute configurations were determined by single-crystal X-ray diffraction and modified Mosher's method.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!