New isocoumarin and stilbenoid derivatives from the tubers of Sparganium stoloniferum (Buch.-Ham.).

A new isocoumarin derivative 8,5'-dihydroxy-6'-methoxy-4-phenyl-5,2'-oxidoisocoumarin (1) and a new stilbenoid derivative methyl 5-hydroxy-2-(2-hydroxyphenyl)benzofuran-4-carboxylate (2) together with nine known compounds (3-11) were isolated from the tubers of Sparganium stoloniferum Buch.-Ham.. Another stilbenoid derivative (3) and a xanthone (4) were identified as new natural products and compounds 5-10 were obtained for the first time from the genus Sparganium. All their structures were elucidated by comprehensive spectroscopic analysis and comparison with available literature information.