Five new tetralones, daldiniones A−E (1−5), three new chromones, 7-hydroxy-5-methoxy-2,3-dimethylchromone (9), 5-methoxy-2-propylchromone (10), and 7ethyl-8-hydroxy-6-methoxy-2,3-dimethylchromone (11), and two new lactones, helicascolides D and E (16 and 17), together with nine known metabolites (6−8, 12−15, and 18− 19) were isolated from the mangrove-derived fungus Daldinia eschscholtzii HJ004. The structures and absolute configurations of the new compounds were determined by analyzing MS and NMR data and utilizing GIAO based 13 C NMR chemical shift calculations and quantum chemical electronic circular dichroism (ECD) calculations. Compounds 9, 13, and 18 showed inhibitory activities against α-glucosidase with IC 50 values of 13, 15, and 16 μM, respectively.
Two new compounds penibenzophenones A-B (1-2), and the synthetic α,β-unsaturated amide alkaloid (E)-tert-butyl(3-cinnamamidopropyl)carbamate (4), newly identified as a natural product, alone with three known ones (3, 5-6) were isolated from the EtOAc extract of the endophytic fungus Penicillium citrinum HL-5126 isolated from the mangrove Bruguiera sexangula var. rhynchopetala collected in the South China Sea. Compound 1 was a chlorinated benzophenone. The structures of 1-6 were elucidated by extensive NMR spectral interpretation, MS data and X-ray analysis. The new compound 2 displayed cytotoxic activity against human A549 cell lines with an IC value of 15.7 μg/mL, and 1 showed antibacterial activity against Staphylococcus aureus with a MIC value of 20 μg/mL.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.