Abstract: | In a previous article we have reported our finding of an unknown vitamin derivative in the serum of cancer patients and in rats transplanted by a malignant tumor. Analysis of this compound extracted from serum of cancer patients, was carried out by I.R., U.V., mass spectrography and nuclear magnetic resonance (N.M.R.) determination. This analysis led us to the conclusion that the compound was a ketone derivative of D3 vitamin: 1-ceto-24-methyl-25-hydroxycholecalciferol, provisionally designated D3C. Enzymatic pathways involved in the biosynthesis of this substance and its possible role in normal and pathological cell division are discussed. |