58 D.S. Lamani et al.
1/(εb − εf ) and an intercept y equal to 1/Kb(εb − εf ), where Kb is the ratio of the slope to the
intercept y.
5.2. Viscosity measurements
Viscosity measurements were carried out using a semimicro-dilution capillary viscometer at room
temperature. Each experiment was performed three times and an average flow time was calculated.
Data were presented as (η/ηo) versus binding ratio, where η is the viscosity of DNA in the presence
of complex and ηo is the viscosity of DNA alone (29).
5.3. Thermal denaturation
Melting studies were carried out by monitoring the absorption of CT-DNA (50 μM) at 260 nm
at various temperatures in the presence (5–10 μM) and absence of each complex. The melting
temperature (Tm) at which 50% of the double-stranded DNA becomes single-stranded and the
curve width (σT), the temperature range between 10% and 90% noticed absorption increases
occurred and calculated as reported (30).
Acknowledgements
D.S.L. thanks the Indian Institute of Science, Bangalore, and Karnataka University, Dharwad, for providing spectral data
and Cochin University, Sophisticated Test & Instrumentation Center, Kochi, Kerala, for the elemental analysis facility,
and we also thank Kuvempu University for awarding a research fellowship.
References
(1) Selvi, S.T.; Mohan, P.S. Spectrosc. Lett. 2002, 35, 439–445.
(2) Toth, J.; Blasko, G.; Dancso, A.; Toke, L.; Nyerges, M. Synth. Commun. 2006, 36, 3581–3589.
(3) (a) Raghavendra, M.; Bhojya Naik, H.S.; Sherigara, B.S. Arkivoc 2006, 15, 153–159; (b) Prakash Naik, H.R.; Bhojya
Naik, H.S.; Ravikumar Naik, T.R.; Raja Naik, H.; Lamani, D.S.; Aravind, T. J. Sulfur Chem. 2008, 29, 583–592.
(4) Loaiza-Rodriguez, P.; Quintero, A.; Rodríguez-Sotres, R.; Solano, J.D.; Lira-Rocha, A. Eur. J. Med. Chem. 2004,
39, 5–10.
(5) Gawande, N.G.; Shingare, M.S. Indian J. Chem. 1987, 26B, 387–389.
(6) Brickner, S.J.; Hutchinson, D.K.; Barbachyn, M.R.; Manninen, M.N.; Ulanowicz, D.A.; Garmon, S.A.; Grega, K.C.;
Hendges, S.K.; Troops, D.S.; Ford, C.W.; Zurenko, G.E. J. Med. Chem. 1996, 39, 673–679.
(7) Look, G.C.; Schullek, J.R.; Homes, C.P.; Chinn, J.P.; Gordon, E.M.; Gallop, M.A. Bioorg. Med. Chem. Lett. 1996,
6, 707–712.
(8) Singh, M.P.; Joseph, T.; Kumar, S.; Lown, J.W. Chem. Res. Toxicol. 1992, 5, 597–607.
(9) TilakaRaj, T.; Ambekar, S.Y. J. Chem. Res. 1988, 50, 537–551.
(10) TilakaRaj, T.; Ambekar, S.Y. J. Chem. Eng. Data 1988, 33, 530–531.
(11) Thulstrup, P.W.; Thormann, T. Biochem. Biophy. Res. Commun. 1999, 254, 416–421.
(12) Barreca, M.L.; Chimirri, A.; Luca, L.D.; Monforte, A.; Monforte, P.; Rao, A.; Zappala, M.; Balzarini, J.; De Clercq,
E.; Pannecouque, C.; Witvrouw, M. Bioorg. Med. Chem. Lett. 2001, 1793–1796.
(13) (a) Lamani, D.S.; Venugopala Reddy, K.R.; Bhojya Naik, H.S.; Savyasachi, A.; Naik, H.R. Nucleos. Nucleot.
Nucl. Acids 2008, 27, 1197–1210; (b) Prakash Naik, H.R.; Bhojya Naik, H.S.; Ravikumar Naik, T.R.; Naik, H.R.;
Raghavendra, M.; Aravinda, T.; Lamani, D.S. Phosphorus Sulfur Silicon Relat. Elem. 2009, 184, 2109–2114.
(14) (a) Nandeshwarappa, B.P.; Aruna Kumar, D.B.; Bhojya Naik, H.S.; Mahadevan, K.M. J. Sulfur Chem. 2005, 27,
373; (b) Ramesh, S.; Bhojya Naik, H.S.; Harish Kumar, H.N. J. Sulfur Chem. 2007, 28, 573–579.
(15) Nandeshwarappa, B.P.;ArunaKumar, D.B.; Kumaraswamy, M.N.; RaviKumar,Y.S.; BhojyaNaik, H.S.; Mahadevan,
K.M. Phosphorus Sulfur Silicon. Relat. Elem. 2006, 181, 1545–1556.
(16) (a) Lamani, D.S.; Venugopala Reddy, K.R.; Bhojya Naik, H.S.; Prakash Naik, H.R.; Sridhar, A.M. J. Macromol.
Sci., Part A 2008, 45, 857–864; (b) Shahabuddin, S.; Gopal, M.; Sathees, M.; Raghavan, C. J. Cancer. Mol. 2007, 3,
139–146.
(17) (a) Prakash Naik, H.R.; Bhojya Naik, H.S.; Ravikumar Naik, T.R.; Raja Naik, H.; Lamani, D.S.;Aravind, T. J. Sulfur
Chem. 2008, 29, 583–592; (b) Prabhakara, M.C.; Basavaraju, B.; Bhojya Naik, H.S. Bioinorg. Chem. Appl. 2007,
320, 3649.
(18) Homes, C.P.; Chinn, J.P.; Look, C.G.; Gordon, E.M.; Gallop, M.A. J. Org. Chem. 1995, 60, 7328–7333.