Spectroscopic probe of distribution of the non-intercalating drug netropsin between DNA and heparin.

Circular dichroism has been used as a monitoring tool to probe the distribution of the non-intercalating drug netropsin (NTPS) between the two biomolecules DNA and heparin. The stoichiometry of the interaction of the individual biomolecules and the drug is determined from conductometric titrations; the titration in each case shows two breaks corresponding to two stoichiometries of interaction. Though netropsin is non-intercalating, DNA wins over heparin in binding the drug due to strong hydrogen bonding capability of NTPS in the minor grooves of DNA through its greater than NH donor groups. Potential hydrogen bond breakers like KF and urea reduce the induced dichroism of NTPS-DNA system, probably dislodging some drug from DNA through hydrogen bond breaking.

Synthesis of novel furan containing DNA minor groove binding oligopeptides related to netropsin for pharmaceutical interest

Certain oligopeptides, structurally related to the antiviral antitumor antibiotic netropsin, have been synthesized. The pyrrole units have been replaced by a furan or difuran moiety. One of the amidines moieties of netropsin has been replaced by certain alicyclic and /or aromatic secondary amines to examine the effect of such structural modification on the antitumor activity of oligopeptides. Eight new compounds were tested for in-vitro cytotoxic activity against Ehrlich ascites carcinoma