Isolation and identification of flavonoids from <i>Coreopsis lanceolata</i> L. petals

<div><p>The methanol extract of <i>Coreopsis lanceolata</i> L. petals was acid-hydrolysed, and 7,3′,4′-trihydroxy-8-methoxyflavanone (<b>1</b>) and 6,3′,4′-trihydroxy-7-methoxyaurone (leptosidin) (<b>2</b>) were successfully isolated. The structure of compound <b>1</b> is designated to flavanone based on X-ray crystallographic analysis and NMR spectroscopic analysis. Compound <b>1</b> showed high-antioxidant effects based on diphenylpicrylhydrazyl radical scavenging assay (94.3% scavenging rate) and superoxide dismutase-like activity assay (23.9% inhibition rate).</p></div

Convenient Synthesis of 1-(Trimethylsilyl)- and 1-(Trimethylstannyl)vinylphosphonates

<div><p></p><p>Dimethyl 1,1-bis(trimethylsilyl)methylphosphonate and dimethyl 1-(trimethylsilyl)-1-(trimethylstannyl)methylphosphonate were succeeded to react with aromatic aldehydes in the presence of methyl benzoate as additive to give the corresponding vinylphosphonates in moderate yields.</p></div