Three pairs of enantiomeric dibenzo-α-pyrone derivatives (-) including two pairs of new racemates (±)-alternaone A () and (±)-alternaone B () and one new enantiomer (-)-alternatiol (), together with five known compounds (-) were isolated from the fungus ZHJG5. Their structures were confirmed by spectroscopic data and single-crystal X-ray diffraction analysis. All enantiomers were separated via chiral high-performance liquid chromatography, with their configurations determined by electronic circular dichroism calculation. Biogenetically, a key epoxy-rearrangement step was proposed for the formation of skeletons in -; (+) , (-)-, and presented moderate antibacterial inhibition on phytopathogenic bacteria pv. and pv. . In the antifungal test, compounds and showed a moderate protective effect against in vivo.
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http://dx.doi.org/10.1021/acs.jafc.0c04106 | DOI Listing |
J Org Chem
December 2024
Department of Pharmacy, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China.
Nine new structurally diverse filicinic acid-based meroterpenoids (-) with four kinds of carbon skeletons were isolated from the rhizomes of . Their structures, including the absolute configurations, were elucidated by comprehensive analysis of spectroscopic data, quantum chemical calculations, and single-crystal X-ray diffraction. Structurally, compounds - feature an unprecedented 6/6/5/6/6/6 hexacyclic system with a rare oxaspiro[4.
View Article and Find Full Text PDFJ Agric Food Chem
December 2024
College of Plant Protection, Southwest University, Chongqing 400715, China.
Etoxazole, a widely used mite growth inhibitor, contains a chiral center in its chemical structure, resulting in two mirror-image enantiomers. These enantiomers of etoxazole display significant differences in biological activity and environmental behavior. In bioassays conducted against , it was observed that S-etoxazole demonstrated approximately 279.
View Article and Find Full Text PDFChem Asian J
December 2024
Govt. Degree College for Men, Srikakulam, Department of Chemistry, Srikakulam, 532001, Srikakulam, INDIA.
The production of enantiomerically pure compounds remains a vital and valuable objective in modern organic chemistry due to their broad applications in fields such as biosensing, optics, electronics, photonics, catalysis, nanotechnology, and drug or DNA delivery. Optically pure α-hydroxy ketones, in particular, are key structural components in many drugs and natural products with significant biological activity. Among these, benzoin type α-hydroxy ketones, which possess two adjacent functional groups, a carbonyl and a hydroxy group, are especially important.
View Article and Find Full Text PDFChemistry
December 2024
Ulsan National Institute of Science and Technology, Chemistry, UNIST-gil 50, Bldg.108, Rm901-5, 44919, Ulsan, KOREA, REPUBLIC OF.
Nanographenes and polycyclic aromatic hydrocarbons, both finite forms of graphene, are promising organic semiconducting materials because their optoelectronic and magnetic properties can be modulated through precise control of their molecular peripheries. Several atomically precise edge structures have been prepared by bottom-up synthesis; however, no systematic elucidation of these edge topologies at the molecular level has been reported. Herein, we describe rationally designed modular syntheses of isomeric dibenzoixenes with diverse molecular peripheries, including cove, zigzag, bay, fjord, and gulf structured.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Sichuan University - Wangjiang Campus: Sichuan University, Chemistry, 29 Wangjiang Rd, 610064, Chengdu, CHINA.
Polyhydroxyalkanoates (PHAs) have attracted broad interest as promising sustainable materials to address plastic pollution and resource scarcity. However, the chemical synthesis of stereoregular PHAs via ring-opening polymerization (ROP) has long been an elusive endeavor. In this contribution, we exploited a robust spiro-salen yttrium complex (Y3) as the catalyst to successfully prepare syndiotactic PHAs with diverse pendent groups.
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