The absence of the diet-derived 7-deazapurine, queuine in artificial liquid diets

Queuine is a derivative of guanine found in the transfer RNAs of most organisms including man. Higher mammals cannot synthesize queuine and must obtain it either from their diets or intestinal microflora. Tumor cells often contain much less queuine in their transfer RNAs than do normal cells. Cancer patients are frequently fed artificial liquid diets or are nourished by chemically defined intravenously administered liquids. In this report we present the results of our examination of five common artificial nutrition preparations obtained from a hospital pharmacy with respect to their content of queuine.