An isolate, diphysin, from the bark of the decay-resistant Costa Rican
tree Dyphysa robinioides was shown to be a dimer (at C-3) of ihydro-4
-(4'-hydroxyphenyl)-5,7-dihydroxycoumarin. Diphysin is an isomer of th
e previously known C-3 dimeric flavanone chamaejasmin, which was also
found in the bark along with isovitexin.