Effect of Ionic Strength on Porphyrin Drugs Interaction with Quadruplex DNA Formed by the Promoter Region of C-myc and Bcl2 Oncogenes

Table 1

UV-Vis absorption titration parameters for TMPyP4, TMPyP3, and TMPyP2 with four different Bcl2 and C-myc G-quadruplex DNA. Soret band hypochromicity is calculated using the formula: % Hypochromicity =[(€_free−€_bound)/€_free]×100. €_free and €_bound are the extinction coefficient of free and bound porphyrin, respectively.

S. No.	Name of quadrupelx DNA and cationic porphyrin	Soret band shift (nm)	Isobestic point (nm)	Percentage hypochromicity
1.	27Bcl2-TMPyP4	423–441	435.5	59.7%
2.	27Bcl2-TMPyP3	417–431	426.5	41.5%
3.	27Bcl2-TMPyP2	No shift	422.0	23.0%
4.	C-myc-TMPyP4	423–439	432.2	52.3%
5.	C-myc-TMPyP3	417–429	425.3	39.5%
6.	C-myc-TMPyP2	No shift	421.7	14.7%