In vitro system for detection of antimetabolites of specific amino acids.

An in vitro system was developed to detect antimetabolites in fermentation liquors of soil microorganisms. This system effectively uncovers antimetabolites of purines and pyrimidines and of selected amino acids with established differences in their biosynthesis by normal cells versus certain malignant cells. Currently these amino acids include: L-asparagine, L-aspartic acid, L-glutamine, L-cysteine (cystine), L-methionine, L-arginine, L-histidine, L-tyrosine, L-phenylalanine, L-tryptophan, L-threonine, and L-serine. It is expected that these antimetabolites could be useful either alone or in combination with specific depleting enzymes in the treatment of malignancies where such an imbalance was established.