Abstract
Quinolylmethylisothioronium salts (1a and 4a) cleave DNA upon irradiation. The cleavage is more than 10-fold enhanced by piperidine treatment and subsequently shows a high preference for guanines. Photolysis of 1a, 2a and 4a in water at lambda greater than 300 nm resulted in photoheterolysis. Irradiation of 1a in 2-propanol gave only products from photohomolysis, irradiation of 1a in methanol and 2a and 4a in 2-propanol resulted in products from both photoheterolysis and photohomolysis. Quantum yields for the disappearance of 1a in water and 2-propanol were determined. The presence or absence of oxygen had no effect in water, whereas oxidation products were observed upon irradiation in methanol and 2-propanol in the presence of oxygen. The guanine specific DNA photoreaction is proposed to take place by alkylation at N7 via the quinolylmethyl carbocation and thus to represent a photoalkylation.
| Original language | English |
|---|---|
| Journal | Photochemistry and Photobiology |
| Volume | 53 |
| Issue number | 3 |
| Pages (from-to) | 299-305 |
| Number of pages | 7 |
| ISSN | 0031-8655 |
| Publication status | Published - Mar 1991 |
Keywords
- Base Sequence
- DNA/radiation effects
- Guanine
- Indicators and Reagents
- Isothiuronium/analogs & derivatives
- Molecular Sequence Data
- Photochemistry
- Plasmids/radiation effects
- Ultraviolet Rays