In this study, three new garcinoic acid dimers, δ,δ-bigarcinoic acid (), δ,δ-bi--garcinoic acid (), and γ,δ-bi--garcinoic acid (), and a new benzophenone derivative, (8)-4-geranyl-3,5-dihydroxybenzophenone (), as well as seven known compounds (-) were isolated from the seeds of . The structures of the new compounds were elucidated using MALDI-TOF-MS and spectroscopic data, including 1D and 2D NMR and electronic circular dichroism spectra. All of the isolated compounds were evaluated for their antimicrobial activity against two oral pathogens, and . Among them, and δ-garcinoic acid () exhibited antimicrobial activity against both of these microorganisms (MICs of 31.3-62.5 μM for and 15.6-31.3 μM for ). These results indicate that some chemical constituents in seeds have potential application in the prevention of oral diseases.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.jnatprod.9b01045 | DOI Listing |
Beilstein J Org Chem
December 2024
Department of Chemical and Geological Sciences, University of Cagliari, S.S. 554, bivio per Sestu, 09042 Monserrato (CA), Italy.
The rising popularity of bioconjugate therapeutics has led to growing interest in late-stage functionalization (LSF) of peptide scaffolds. α,β-Unsaturated amino acids like dehydroalanine (Dha) derivatives have emerged as particularly useful structures, as the electron-deficient olefin moiety can engage in late-stage functionalization reactions, like a Giese-type reaction. Cheap and widely available building blocks like organohalides can be converted into alkyl radicals by means of photoinduced silane-mediated halogen-atom transfer (XAT) to offer a mild and straightforward methodology of alkylation.
View Article and Find Full Text PDFFitoterapia
December 2024
Graduate School of Pharmaceutical Sciences, Tokushima University, Tokushima 770-8505, Japan. Electronic address:
Previously undescribed benzophenone rhamnosides, triadenosides A-F (1-6), were isolated from the aerial parts of Triadenum japonicum (Blume) Makino (Hypericaceae), where known compounds including benzophenone rhamnosides (7 and 8), benzophenone C-glucoside (9), flavonols and their glycosides (10-17), and biflavone (18) were also isolated and identified. Detailed spectroscopic analysis revealed that triadenoside A (1) was 2,3',5'-trihydroxy-4,6-dimethoxybenzophenone 2-O-α-L-rhamnopyranoside, while the absolute configuration of the rhamnosyl moiety was confirmed by HPLC analysis. Triadenosides B-E (2-5) were assigned as acetyl derivatives of 1 in their rhamnosyl moieties.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Photochemical deracemization has emerged as one of the most straightforward approaches to access highly enantioenriched compounds in recent years. While excited-state events such as energy transfer, single electron transfer, and ligand-to-metal charge transfer have been leveraged to promote stereoablation, approaches relying on hydrogen atom transfer, which circumvent the limitations imposed by the triplet energy and redox potential of racemic substrates, remain underexplored. Conceptually, the most attractive method for tertiary stereocenter deracemization might be hydrogen atom abstraction followed by hydrogen atom donation.
View Article and Find Full Text PDFChemistry
December 2024
Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
The dimeric calcium and magnesium hydrides, [(BDI)AeH] [BDI=HC{(Me)CNDipp}, Dipp=2,6-i-PrCH; Ae=Mg or Ca] do not react with PhGeH in non-coordinating solvent. Addition of THF, however, induces deprotonation and access to monomeric Ae-germanide complexes, [(BDI)Ae{GePh}(THF)], both of which have been structurally characterized. Although this process is facile when Ae=Ca, the analogous magnesium-based reaction requires heating to temperatures >100 °C, under which conditions germanide formation is complicated by THF ring opening and the generation of an alkaline earth germyl-C-terminated n-butoxide, [(BDI)Mg{μ-O(CH)GePh}].
View Article and Find Full Text PDFFront Microbiol
November 2024
College of Life Science, Shandong Normal University, Jinan, China.
Manganese (Mn) oxidation processes have garnered significant attention recently due to their potential for degrading organic pollutants. These processes are primarily catalyzed by Mn(II) oxidases. F01, an endophytic bacterium derived from wetland plants, has demonstrated Mn(II)-oxidizing capacity.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!