Three new diketopiperazine alkaloids, including two oxepine-containing diketopiperazines, chrysopiperazines A and B ( and ), and one quinazoline-containing diketopiperazine, chrysopiperazine C (), together with three known analogues (, , and ), were isolated from the gorgonian-derived fungus. The relative and absolute configurations of C-3 and C-15 in and , C-3 and C-14 in were established by NOE modified Marfey's analysis and electronic circular dichroism (ECD) calculations. Particularly, the absolute configurations of C-19 in and , which was very challenging to be identified due to the flexible conformation in a short aliphatic chain, were successfully determined by the vibrational circular dichroism (VCD) method, supplying with a reliable and optional method to define the absolute configurations. Additionally, this is the first report on oxepine-containing diketopiperazines from the genus .
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6562614 | PMC |
| http://dx.doi.org/10.3390/md17050250 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Five new indole diterpenoids, shearinines U-Y (2-6), and the known compound 22,23-dehydro-shearinine A (1) were isolated from cultures of the entomogenous fungus sp. Their structures were elucidated primarily by NMR experiments. The absolute configurations of 2-6 were assigned by electronic circular dichroism calculations, respectively.
View Article and Find Full Text PDFA Cedrane and a Fusarin from the Algicolous Fungus Fusarium graminearum 12Ⅱ2N and Response to Mycoparasitism.
Chem Biodivers
January 2025
Yantai Institute of Coastal Zone Research, Coastal biology and Bioresource Utilization, 17 Chunhui Road, 264003, Yantai, CHINA.
The fungal genus Fusarium is a treasure-trove of structurally diverse secondary metabolites, contributed greatly by marine-derived strains. A new cedrane sesquiterpene, fusacedrol (1), and a new fusarin member, fusarin M (2), were isolated from F. graminearum 12Ⅱ2N that was isolated as an endophyte from the marine brown alga Sargassum sp.
View Article and Find Full Text PDFDiscovery of highly oxygenated cytochalasans with antiproliferative activity from an endophytic fungus Boeremia exigua.
Bioorg Chem
January 2025
Anhui Province Key Laboratory of Bioactive Natural Products, School of Pharmacy, Anhui University of Chinese Medicine, Hefei 230012 China; Science & Technology Industrial Parks of Anhui University of Chinese Medicine, Hefei 230012 China. Electronic address:
Eleven cytochalasans (1-11), including six undescribed analogues (1-3 and 5-7) and a new natural product (4), were obtained from the endophytic fungus Boeremia exigua. Their structures and absolute configurations were determined by a combination of extensive spectroscopic techniques, electron circular dichroism (ECD), and single-crystal X-ray diffraction. Boerelasin E (1) represented the first cytochalasan possessing a cis-configured Δ double bond.
View Article and Find Full Text PDFCarbohydrate-active enzyme-catalyzed stereoselective glycosylation of complex natural product glycosides.
Enzyme Microb Technol
January 2025
Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610213, China. Electronic address:
Natural products and their derivatives are precious resources with extensive applications in various industrial fields. Enzymatic glycosylation is an efficient approach for chemical structure diversification and biological activity alternation of natural products. Herein, we reported a stereoselective glycosylation of complex natural product glycosides catalyzed by two carbohydrate-active enzymes (CAZys).
View Article and Find Full Text PDFSpin-Orbit Coupling and Admixture Coefficients in SA-CASSCF and MS-CASPT2, and Triplet Excitation Yield Simulated via Trajectory Surface Hopping and Calibrated SA-CASSCF in 1,2-Dioxetane Derivatives.
J Phys Chem A
January 2025
Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States.
The energy gaps, spin-orbit coupling (SOC), and admixture coefficients over a series of the configurations are evaluated by the SA-CASSCF/6-31G, SA-CASSCF/6-31G*, SA-CASSCF/ANO-RCC-VDZP, and MS-CASPT2/ANO-RCC-VDZP to reveal the extent of the inaccuracy of the SA-CASSCF. By comparing the mean absolute errors for the energy gaps and the admixture coefficient magnitudes (ACMs) measured between the SA-CASSCF/6-31G, SA-CASSCF/6-31G*, or SA-CASSCF/ANO-RCC-VDZP and the MS-CASPT2/ANO-RCC-VDZP, the SA-CASSCF/6-31G is selected as the electronic structure method in the nonadiabatic molecular dynamics simulation. The major components of the ACMs of the SA-CASSCF/6-31G and MS-CASPT2/ANO-RCC-VDZP are identified and compared; we find that the ACMs are underestimated by the SA-CASSCF/6-31G, which is verified by the reasonable triplet quantum yield simulated by the trajectory surface hopping and the calibrated SA-CASSCF/6-31G.
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!