FIG. 1.

Structures of flavonoid dimers, flavonoid monomers with ethylene glycol linker and apigenin. The “n” is the number of ethylene glycol units present in the linker of the flavonoid dimers (9a to 9k-1). The “av” is the average number of ethylene glycol units used during flavonoid dimer synthesis. The “x” in 10a and 10b is the number of ethylene glycol units added to the flavonoid monomers (10a and 10b). 10a and 10b were used as controls. The synthesis of these compounds have been reported previously (8).