Bioactive coumarin derivatives from the fern Cyclosorus interruptus

Three new coumarin derivatives, compounds 1-3, three new furanocoumarins, compounds 4-6, and a novel dioxocane derivative, compound 7,were isolated from the fern Cyclosorus interruptus (Willd.) H. Ito. Based on spectrometric and spectroscopic analysis (FAB or EI mass spectrometry as well as 1D and 2D NMR experiments) their structures were characterised as 5,7-dihydroxy-6-methyl-4-phenyl-8-(3-phenylpropionyl)-1-benzopyran-2-one (1), 5,7-dihydroxy-6-methyl-4-phenyl-8-(3-phenyl-trans-acryloyl)-1 -benzopyran-2-one (2), 5,7-dihydroxy-8-(2-hydroxy-3-phenylpropionyl)-6-methyl-4-phenyl-1-benzopyran-2-one (3), 8-benzyl-5,8-dihydroxy-6-methyl-4-phenylfuro[2,3-h]-1-benzopyran-2,9-dione (4), 8-benzyl-5,8 beta-,9 beta -trihydroxy-6-methyl-4-phenyl-8,9-dihydro-furo[2,3-h]-1-benzopyran-2-one (5), 8-benzyl-5,8 beta ,9 alpha -trihydroxy-6-methyl-4-phenyl-8,9-dihydro-furo[2,3-h]-1-benzopyran-2-one (6) and 5,11-dihydroxy-6-methyl-4-phenyl-11-(1-phenylmethyl)-7,10-dioxocane [5,6-h]-1-benzopyran-2,12-dione (7). For these compounds we propose the trivial names interruptins A-F. Compounds 1, 5/6 and 7 showed antibacterial activity while compounds 1 and 2 were cytotoxic to a KB cell line.