title: Structural aspects of N-hydroxy-N'-aminoguanidine derivatives as inhibitors of L1210 cell growth and ribonucleotide reductase activity.
abstract: Previous studies have shown that N-hydroxy-N'-aminoguanidine (HAG) derivatives [RCH = NNHC(= NH)NHOH-tosylate] inhibit ribonucleotide reductase activity and block the growth of leukemia L1210 cells and human colon carcinoma, HT-29, cells in culture. In the current studies, the role of the side chains and the location of the bond of the side chain moiety to HAG were investigated using a new series of HAG derivatives which contained as the R-group--cyclohexyl, phenyl-, pyridyl- or napthyl moieties. The effects of these compounds as inhibitors of L1210 cell growth and ribonucleotide reductase activity were compared with the parent compound. N-hydroxy-N'-aminoguanidine was less inhibitory to ribonucleotide reductase activity and L1210 cell growth than hydroxyurea. The phenyl-HAG compounds which included 1-benzyloxybenzylidene- and 4-cyclohexylmethoxybenzylidene-HAG inhibited CDP reductase with IC50s which ranged from 50-110 microM. 1-Naphthylmethylene-HAG was more inhibitory than 2-naphthylmethylene-HAG and more inhibitory than the phenyl-HAG compounds. 2-Pyridylmethylene-HAG was more inhibitory than 3-pyridylmethylene- or 4-pyridylmethylene-HAG. While HAG inhibited CDP and ADP reductase activities essentially to the same extent, the HAG-derivatives inhibited ADP reductase activity to a greater extent than CDP reductase activity. Cyclohexylmethylene-HAG did not inhibit either L1210 cell growth or ribonucleotide reductase activity. There was good correlation between the inhibition of ribonucleotide reductase activity and L1210 cell growth by these HAG-derivatives. These data indicate that not only is the nature of the side chain substitution important, but also the location of the HAG-moiety on the ring position.
authors.affiliation: Department of Biochemistry, East Carolina University School of Medicine, Greenville, NC 27858.
authors.forename: J G
authors.initials: JG
authors.lastname: Cory
authors.forename: A H
authors.initials: AH
authors.lastname: Cory
authors.forename: N K
authors.initials: NK
authors.lastname: Raber
authors.forename: A
authors.initials: A
authors.lastname: Narayanan
authors.forename: S W
authors.initials: SW
authors.lastname: Schneller
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D006146:Guanidines / Q000737:chemistry / Q000494:pharmacology*; D007939:Leukemia L1210 / Q000188:drug therapy* / Q000473:pathology; D051379:Mice; D012264:Ribonucleotide Reductases / Q000037:antagonists & inhibitors*; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000201:enzymology / Q000473:pathology
chemical_list: D006146:Guanidines; C062817:N-hydroxy-N'-aminoguanidine; D012264:Ribonucleotide Reductases