Two Metabolites with DNA-Binding Affinity from the Mangrove Fungus Xylaria sp (#2508) from the South China Sea Coast

A novel metabolite xylopyridine A (1), together with a known compound pyrocoll (2), was isolated from mangrove endophytic fungus Xylaria sp. (#2508) collected from the South China Sea coast. Their structures were established on the basis of spectroscopic analysis, especially 2D-NMR. Their affinities toward calf thymus (CT) DNA were studied by fluorescence quenching and spectrophotometric titration experiments. The results indicate that 1 showes strong DNA-binding affinity presumably via an intercalation mechanism, thus it is exploitable as strong DNA-binders.