UV-guided isolation of polyynes and polyenes from the roots of Codonopsis pilosula

The UV-guided isolation of polyacetylenes from the crude extract of Codonopsis pilosula has successfully led to the characterization of five new polyynes, pilosulynes A-E (1-5), and two new polyenes, pilosulynes F and G (6 and 7), as well as five known analogues (8-12). Their structures were determined by spectroscopic methods, including ICD and 1D/2D NMR experiments. The absolute configurations of the 6,7-diol moiety of the isolated compounds were determined by the Snatzke's method, which revealed an induced circular dichroism after the addition of dimolybdenum tetraacetate in DMSO. Compound 6 exhibited anti-HCV activity in the HCVcc infection assay with an EC₅₀ value of 47.2 μM.