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The light emission from bleomycin + Fe2++ O2 and bleomycin + Fe3++ H2O2 has been studied. Chemilumines-cence kinetics and fluorescence spectra were measured. The fluorescence spectra were time-dependent exhibiting maxima at 350 and 400 nm when Xeu. = 313 nm, and 430, 450 and 520 nm for Arac = 366 ran.The obtained results indicate that during oxidative degradation of bleomycin new fluorescing products are formed, which undergo chemiexcitation.

The peroxidation of DOPA in the presence of iron salts, haemin and cytochrome c was investigated using a chemiluminescent method.The spectral distribution of chemiluminescence and fluorescence were measured. The chemiluminescence spectra revealed one broad blue band and bands with maxima at 580, 640 and 700 run.Light emission was inhibited by singlet oxygen quenchers and HO radical inhibitors (5,5-dimethylcyclohexandione - 1,3; tyrosine, histidine, thiourea and mannitol).The light emission from 1O2-pairs seems to be partially responsible for the chemiluminescence observed during oxidative degradation of DOPA in the presence of Fe2+. A mechanism for the 1O2 generation is proposed.

This study was undertaken to establish the mechanism of the chemiluminescence in oxidation of doxycycline by H2O2. The spectral distribution of chemiluminescence and fluorescence were measured. The chemiluminescence spectrum revelated one broad blue-green band and bands with maxima at 580, 640 and 700 nm. The blue-green band matched the fluorescence bands whereas the bands at 580 nm, 640 and 700 nm were similar to those observed for singlet molecular oxygen. The effect of singlet oxygen quenchers on the chemiluminescence spectra was studied. A mechanism for the generation of electronically excited products of the doxycycline oxidation is proposed.

The anticancer drugs: adriamycin, farmorubicin and mitomycin C greatly enhance the generation of hydroxyl radicals (HO.) from H2O2 in the presence of Co(II) ions (CoCl2) at pH 7.4 and 8, as measured by the deoxyribose assay. Catalase, hydroxyl radical scavengers (mannitol, cysteine, glutathione, thiourea, lactic dehydrogenase) inhibited the degradation of deoxyribose confirming that HO-radicals are responsible for the degradation of the carbohydrate.

Catecholamines were found to increase deoxyribose degradation by the bleomycin - Fe(III) + H2O2 system. Catalase, superoxide dismutase and hydroxyl radical scavengers such as mannitol, cysteine, glutathion and histidine inhibited the degradation of deoxyribose, suggesting that hydroxyl radicals are responsible for the oxidative damage of the carbohydrate.

The autoxidation and oxidation of doxycycline in the presence of hydrogen peroxide were investigated using spectrophotometric and chemiluminescent methods.The effects of reagent concentrations, pH, 1O2-quenchers and oxygen free radicals scavengers on the light emission were measured.The results show that electronically excited products and reactive oxygen species are directly involved in the oxidation process.

Catecholamines (adrenaline, noradrenaline, dopamine, isoprotenerol) and DOPA greatly accelerate the generation of hydroxyl radicals from H2O2in the presence of Fe‐ions as studied by the deoxyribose assay.Hydroxyl radical scavengers (formate, methanol, mannitol, cysteine, glutathione, histidine) and catalase inhibited the degradation of deoxyribose confirming that HO‐radicals are responsible for the degradation of the sugar.

The effect of the Superoxide radical (O2-)-, hydroxyl radical (HO')-inhibitors, singlet oxygen (1O2)-quenchers and catalase on the light emission during autoxidation reaction of oxytetracycline was measured. The influence of the 1O2-quenchers was investigated quantitatively and the rate constants were established.