Tumour inhibiting methylhydrazino compounds such as 1-methyl-2-benzyl-hydrazine phosphate and 1-methyl-2-( p-isopropylcarbamoyl-benzyl)-hydrazine hydro-chloride in aqueous solution in the presence of molecular oxygen cause a degradation of deoxyribonucleic acid (DNA), whereby the DNA molecule is split into smaller fragments without substantial destruction of its double helix structure. This degradation is inhibited by catalase, by peroxydase and by cysteamine, whereas cysteine has only a minor influence. The degrading action on DNA of the methylhydrazino compounds is due to the formation of hydrogen peroxide during their autoxidation. From experimental evidence it is concluded that hydrogen peroxide is formed by a chain reaction with free radicals as intermediates. In the course of autoxidation of the methylhydrazino compounds, strong reducing agents are formed which can cause the formation of OH radicals from hydrogen peroxide. As is known, the latter radicals are very reactive and can cause the degradation of DNA. DNA can be used as a reagent for indicating the presence of OH radicals. It cannot be claimed at present that an attack on DNA is the deciding factor for the cytotoxic effect of the methylhydrazino compounds.

Der pro-oxydative Effekt tumorhemmender Methylhydrazin-Verbindungen

A demonstration of the vacuome and the Golgi apparatus as independent cytoplasmic components in the fresh eggs of the frog

Both giant and small unilamellar vesicles of functionalized surfactant 1 (potassium O,O‘-didodecylphosphorodithioate) were subjected to oxidation, which converts 1 into disulfide-linked dimer 4 [bi...

Oxidative destruction of vesicles of a functionalized surfactant

Hydroxyapatite and calcium hydrophosphate peroxo solvates were synthesized and characterized by IR spectroscopy, powder X-ray diffraction, and TGA to be used as biocompatible and antibacterial medicaments in manufacturing calcium phosphate bioceramics for implantations in orthopedics and dentistry. A wide range of hydrogen peroxide percentages in stable mixtures of mCa5(PO4)3(OH) + nCaHPO4 · H2O2 · H2O (ranging from 0.5 to 18%) allows composites to be prepared with a tailored active oxygen content.

Syed Husain

Papers

Perphosphoric acids and perphosphates