Specific inhibition of type II inosine monophosphate dehydrogenase activity of Tmolt4 T cell human leukaemia cells by 3-methoxy and di-benzohydroxamic acids, maleic hydrazide and malonic acids.
Small-molecular-weight benzohydroxamic and malonic acids and maleic hydrazide proved to be potent inhibitors of the activity of human Tmolt4 leukaemia Type II IMP (inosine monophosphate) dehydrogenase (IMPDH) activity. They were competitive inhibitors with respect to IMPDH demonstrating Ki values in the range 2.57-41.3 microM, less than half the values of the IC50 (microM) for the inhibition of Type II IMPDH. The IC50 microM values positively correlated with the ability of each compound to inhibit crude IMPDH activity, de-novo purine and DNA syntheses and growth of the T leukaemia cell line. Compounds were not inhibitors of Type I IMPDH. Type I IMPDH predominates in normal resting cells compared with Type II which is found in rapidly proliferating cells. Discovery of agents which would selectivity target IMPDH found in proliferating cells should eliminate any antineoplastic therapeutic toxic effects in normal cells of the body.
Hall
I H
IH
Division of Medicinal Chemistry and Natural Products, School of Pharmacy, University of North Carolina, Chapel Hill 27599-7360, USA.
Barnes
B J
BJ
Ward
E S
ES
Wheaton
J R
JR
Izydore
R A
RA
D000970:Antineoplastic Agents / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects*; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology*; D007168:IMP Dehydrogenase / Q000187:drug effects / Q000378:metabolism*; D007291:Inosine Monophosphate; D015458:Leukemia, T-Cell / Q000473:pathology; D008300:Maleic Hydrazide / Q000494:pharmacology; D008314:Malonates / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects
D000970:Antineoplastic Agents; D006877:Hydroxamic Acids; D008314:Malonates; D007291:Inosine Monophosphate; C030290:malonic acid; D007168:IMP Dehydrogenase; C006696:benzohydroxamic acid; D008300:Maleic Hydrazide