Six undescribed macrocyclic daphnane orthoesters, stelleratenoids A-F (1-6), were isolated from the roots of Stellera chamaejasme L. Their structures were elucidated by extensive spectroscopic analyses, including HRESIMS and NMR spectra. Compound 1 features an unusual terminal double bond at C-2/C-19 in the 1α-alkyldaphnane lactone skeleton.
View Article and Find Full Text PDFPear is one of the most popular fruits in the world. With the fruit ripening, a series of physiological changes have taken place in fragrant pear, but up to now, the research on the metabolism and biological activity of phenolic compounds in different growth stages of fragrant pear is still lacking. In this study, four kinds of Xinjiang pears were selected as research objects, and the changes of phenolic content, antioxidant capacity, cell protection and whitening activity during fruit development were analyzed.
View Article and Find Full Text PDFJ Asian Nat Prod Res
September 2021
During our continuous efforts to pursue antifungal agents, some calycanthaceous alkaloid analogs showed diverse and promising bioactivities. Therefore, 34 new calycanthaceous alkaloid derivatives were further prepared and screened for bioactivities. As a result of the evaluation against a great deal of plant pathogen fungi, bacteria and human pathogenic fungi, a majority of them displayed potent bioactivity.
View Article and Find Full Text PDFThree new withanolides (1-3), named as daturanolide A-C, along with six known withanolides (4-9) were isolated from the flowers of Datura metel L. Their structures with absolute configurations were elucidated by a series of spectroscopic methods, electronic circular dichroism (ECD) analyses, and X-ray crystallography. All the isolates were evaluated for cytotoxicity against five human cancer cell lines (HCT116, U87-MG, NCI-H460, BGC823, and HepG2), and 6 exhibited marked cytotoxicity.
View Article and Find Full Text PDFFischeriana A (1), a new meroterpenoid with a rare carbon skeleton, along with one of its known biosynthesis-related compounds 2,4-dihydroxy-6-methoxyacetophenone (2) and two known ent-abietane-type diterpenoids (3-4), were isolated from the roots of Euphorbia fischeriana. Their structures, including the stereochemistry, were elucidated using comprehensive spectroscopic methods, single-crystal X-ray diffraction, and electronic circular dichroism analysis. Compound 1 was found to be made up of an unusual heptacyclic ring system (6/6/5/5/5/6/6) featuring a modified ent-abietane diterpene with a phloroglucinol moiety.
View Article and Find Full Text PDFTwo new sesquiterpenoids, named 2α-hydroxyxylaranol B (1) and 4β-hydroxyxylaranol B (2), together with a known diterpenoid 3,4-seco-sonderianol (3) were isolated from the fermentation of endophytic fungus J3 of Ceriops tagal. Their structures were elucidated based on spectroscopic methods including 1D and 2D NMR (HMQC, (1)H-(1)H COSY and HMBC). All compounds were evaluated for their cytotoxic activities by MTT method, and compound 3 exhibited cytotoxic activities against K562, SGC-7901, and BEL-7402 cell lines.
View Article and Find Full Text PDF