Relation of Amino Acids to Trypanocidal Activity of Parasorbic Acid *

With techniques and materials previously described5 a number of lactones (both naturally occurring and synthetic), and some related compounds, have been shown to have definite in vitro trypanocidal activity. It was further shown that these compounds have therapeutic effect in vivo. The concept that specific chemical substances can interfere with the action of a chemotherapeutic agent provides an important starting point for the rational synthesis of biologically active compounds and the study of biochemorphology. Although the most important stimulus for this view came from the discovery of the striking relationship between PABA and the sulfonamides, there are many chemically unrelated substances which also interfere with sulfonamide activity. In fact, the earliest examples of drug antagonisms, between SHcompounds and arsenic or mercury, are clearly not between related chemical structures. The present studies deal with an attempt to relate the recently discovered trypanocidal activity of a group of compounds (represented by a typical member of the group-parasorbic acid) to some known metabolic function.