Cytotoxic lignans from the roots and rhizomes of Diphylleia sinensis, a China's endemic plant species.

Eight novel arylnaphthalide lactone lignans, designated as diphylignan A-H (1-8), and a new dibenzyltyrolactone lignan, designated as diphylignan I (9), were isolated from the roots and rhizomes of Diphylleia sinensis, along with two additional novel natural products (11 and 14) and four known metabolites (10, 12, 13, 15). The structural and stereochemical characterization of these compounds was accomplished using NMR spectroscopy and electronic circular dichroism (ECD) analysis. The cytotoxic activities of all isolated compounds were assessed against A-549 and SMMC-7721 cell lines.

Lignans from the Roots and Rhizomes of and Their Cytotoxic Activities.

One new dibenzyltyrolactone lignan dysoslignan A (), three new arylnaphthalide lignans dysoslignan B-C (-), along with fourteen known metabolites (-), were isolated from the roots and rhizomes of . Their structures and stereochemistry were determined from analysis of NMR spectroscopic and circular dichroism (CD) data. Compound represents the first report of naturally occurring arylnaphthalide lignan triglycoside.

Dysosmaflavonoid A-F, new flavonols with potent DPPH radical scavenging activity from Dysosma versipellis.

Six new flavonols, including four glucosylated flavonols (dysosmaflavonoid A-D), one phenylpropanoid-substituted flavonol (dysosmaflavonoid E), and one phenyl-substituted flavonol (dysosmaflavonoid F), together with five known analogues, were isolated from the roots and rhizomes of Dysosma versipellis. Their structures were elucidated by comprehensive analysis of their NMR, IR, UV, HRESIMS, and HPLC data. The antioxidant activities of all isolated compounds were examined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay.

Structurally diverse biflavonoids from and their bioactivity.

Five pairs of new biflavonoid enantiomers, (±)-dysosmabiflavonoids A-E (1-5), two new biflavonoids, dysosmabiflavonoids F-G (6-7), and four biosynthetically related precursors (8-11) were isolated from the roots and rhizomes of . Their structures were elucidated by extensive spectroscopic analysis, including HR-ESI-MS and 2D NMR. Their absolute configurations were determined by comparison of the calculated and experimental ECD spectra.