ABSTRACT
High-performance liquid chromatographic and TLC methods were developed for the determination of desacetylvinblastine amide base (vindesine), a chemically modified Catharanthus alkaloid presently in clinical evaluation. Both methods permit the detection of 6,7-dihydrovindesine and vindesine Nb'-oxide, the principal by-product in the chemical conversion of vinblastine to vindesine. The methods are applicable to both the sulfate salts and the free bases of the chemical substances described.
Subject(s)
Vinca Alkaloids/analysis , Chromatography, High Pressure Liquid , Chromatography, Thin Layer , MethodsABSTRACT
Exploration of the effects of "minor" structural differences on the antitumor activity and toxicity of dimeric Catharanthus alkaloids resulted in the preparation of deacetylvinblastine amide (vindesine, VDS) from either vinblastine (VLB) or deacetylvinblastine. Adequate amounts of vindesine for biological testing were prepared by preferential hydrazinolysis of the C23-ester in the vindoline moiety of VLB, followed by hydrogenolysis of the resulting deacetylvinblastine hydrazide. Vindesine in its activity spectrum against rodent tumor systems resembles vincristine (VCR) rather than its parent VLB, while its neurotoxic potential appears to be less than that of VCR. The experimental models developed to estimate this potential include in vitro measurements of axoplasmic transport effects in the cat sciatic nerve and the estimation of neuromuscular disturbances in chickens and monkeys by vindesine in comparison with VCR. A radioimmunoassay for VLB, VCR, and VDS, developed by means of deacetylvinblastine acid azide, has been used to study the pharmacokinetics of vindesine in man. The clinical investigation of vindesine is in progress. Deacetylvinblastine, in contrast to earlier reports, showed activity against several murine tumor systems.
