By the addition of different amount of [ds.DNA], two different behavior were observed; hypochromic effect
that is due to the interaction of electronic state of binding chromophore and ds.DNA bases (I* of the binding drugs and I of the nucleotide bases couple) which ultimately reduces the probability of transition and hence hypochromic effect
observed in both the ferrocene derivatives.
While the addition of piperidine in the solution causes hypochromic effect
along with red shifting was observed (~10 nm).
Secondly, the alkaline extract exerted a marked hypochromic effect
on the yellow chromogen, again minimizing interference without the need to include a correction factor.
The intercalative binding of drug with DNA is associated with hypochromic effect
and a large red shift while the groove binding and electrostatic interaction may be associated with hypochromic and/or hyperchromic effect.
The absorption spectra help in suggesting the groove binding of the compounds as hyperchromic effect is usually associated with the groove binding of the compounds and hypochromic effect
may be associated with intercalative and/or groove binding .
In contrast, the signal at = 268 nm exhibited hypochromic effect
(decrease in absorbance) when the concentration of CTAB was increased in a solution containing constant amount of 5-FU.
The self-organization of adenosine 5'-triphosphate and adenosine 5'-diphosphate in aqueous solution as determined from ultraviolet hypochromic effects