Potential antitumor agents via inhibitors of L-asparagine synthetase: substituted sulfonamides and sulfonyl hydrazides related to glutamine.

A series of 4-(substituted aminosulfonyl)- and 4-(substituted hydrazinosulfonyl)-2-aminobutanoic acids, compounds structurally related to glutamine, was synthesized as potential inhibitors of L-asparagine synthetase and subjected to screening as antitumor agents. Target amino acids were obtained by condensation of a blocked reactive sulfonyl chloride with the appropriate amine or hydrazide, followed by deblocking with hydrogen--palladium or liquid hydrogen fluoride--anisole. Neither the target compounds nor their protected precursors inhibited the enzyme from L5178Y/AR or prolonged the life of mice with P-388 lymphocytic leukemia. However, DL-4,4'-dithiobis[2-(benzyloxycarbonylamino)butanoic acid], an intermediate in the synthesis of the target amino acids, exhibited 90% inhibition of L-asparagine synthetase at 10 mM.