Bioactive coumarin derivatives from the fern Cyclosorus interruptus

Three new coumarin derivatives, compounds 1-3, three new furanocoumarins, c ompounds 4-6, and a novel dioxocane derivative, compound 7,were isolated fr om the fern Cyclosorus interruptus (Willd.) H. Ito. Based on spectrometric and spectroscopic analysis (FAB or EI mass spectrometry as well as 1D and 2 D NMR experiments) their structures were characterised as 5,7-dihydroxy-6-m ethyl-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-d ihydro-furo[2,3-h]-1-benzopyran-2-one (5), 8-benzyl-5,8 beta ,9 alpha -trih ydroxy-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 n ames interruptins A-F. Compounds 1, 5/6 and 7 showed antibacterial activity while compounds 1 and 2 were cytotoxic to a KB cell line.