... and acceptor, N is the refractive index ofthe med-ium, F is the fluorescence quantum yield ofthe donor in the absence ofthe acceptor and J is the overlap integralbetween the donor fluorescence ... ofthe emission spectrum ofthe donor with the absorption spectrum ofthe acceptor. The energy transferefficiency E is related to the distance (r0) between acceptorand donor, and also to the ... genistein. The A and Crings ofthe isoflavones are similar to the A and B rings of oestra-diol. The actual distance between the two hydroxyl groups on both the molecules is nearly identical; these...