[Identification of the functional activity of synthetic polyamine analogues using a biotest system based on highly proliferating cultured human cells].

A new biotest system was developed based on highly proliferating human cell cultures (lines LNCaP and PC-3). With the help of this system, two known synthetic polyamines--alpha-difluoromethylornithine (DFMO) and methylglioxalbis(guanylhydrason) (MGBG)--as well as four new synthetic analogues difenyl containing amines (DFCA-1-DFCA-4) with molecular weights of 725.5 (DFCA-1), 755.5 (DFCA-2), 655.5 (DFCA-3), and 681.5 Da (DFCA-4) were tested. In this biotest system, DFMO (0.1-400 microM) did not reveal functional activity, whereas for MGBG a cytotoxic effect was registered (100-200 microM). DFCA-1, DFCA-2, and DFCA-4 had a similar effect at concentrations of 10 microM and higher; DFCA-3, at a concentration of 50 microM and higher. Thus, DFCA-1 has a higher level of antiproliferating activity and may be considered as the most potent cytostatic agent.

Synthesis and preliminary antileukemic studies of cyclic mitoguazone analogues.

Analogues of mitoguazone bearing a terminal amidino group as a part of the seven-membered ring of 1,3-diazepine and six-membered ring of pyrimidine were prepared in order to evaluate in vivo antileukemic action towards L1210 leukemia in mice. Preliminary pharmacological screening showed that the investigated compounds increase the life span (T/C%) of the treated mice in comparison with the untreated animals. The strongest antineoplastic effect was exhibited by compound 8.

Biochemical and chemical characterization of trifluoromethylglyoxal bis(guanylhydrazone), a close analog of the antileukemic drug mitoguazone.

In order to study the structure-activity relationships of bis(guanylhydrazone) type polyamine antimetabolites, trifluoromethylglyoxal bis(guanylhydrazone) (CF3-GBG), a close analog of the antileukemic drug methylglyoxal bis(guanylhydrazone) (mitoguazone, MGBG) was synthesized according to a novel modification of previous methods, yielding single crystals. Single-crystal X-ray crystallography revealed the presence of an isomer different from the one detected in the case of MGBG and all other bis(guanylhydrazones) so far studied. In contrast to MGBG, CF3-GBG was shown to be a very weak inhibitor of yeast adenosylmethionine decarboxylase, being thus devoid of value as a polyamine antimetabolite. In addition, the compound did not have antiproliferative activity against mouse L1210 leukemia cells in vitro. As long as analogous isomers of the two compounds are not available, no conclusions can be drawn about the reasons lying behind the drastical differences between their biological properties.

Biochemical properties and crystal structure of ethylmethylglyoxal bis(guanylhydrazone) sulfate--an extremely powerful novel inhibitor of adenosylmethionine decarboxylase.

Ethylmethylglyoxal bis(guanylhydrazone) (EMGBG) sulfate, an analog of the well-known anti-leukemic drug methylglyoxal bis(guanylhydrazone), was synthesized. It was shown to be an extremely powerful competitive inhibitor of eukaryotic S-adenosylmethionine decarboxylase, with an apparent Ki value 12 nM. Thus, it appears to be the most powerful known inhibitor of the enzyme, being almost an order of magnitude more powerful than the corresponding ethylglyoxal derivative. It neither inhibited the proliferation of mouse L1210 leukemia cells in vitro, nor did it potentiate the growth inhibition produced by alpha-difluoromethyl ornithine. In this respect, its properties are closely related to those of dimethylglyoxal, ethylglyoxal and propylglyoxal bis(guanylhydrazones), while in striking contrast to those of the antiproliferative glyoxal and methylglyoxal analogs. EMGBG also inhibited intestinal diamine oxidase activity (Ki 0.7 microM). EMGBG sulfate was crystallized from water, giving orthorhombic crystals (space group Pbcn). Their crystal and molecular structure was determined by X-ray diffraction methods. The carbon-nitrogen double bonds between the ethylmethylglyoxal part and the aminoguanidine moieties were found to have the same configuration as they are known to have in the salts of glyoxal, methylglyoxal and propylglyoxal bis(guanylhydrazones). The glyoxal bis(guanylhydrazone) chain of the EMGBG cation deviated strongly from planarity, thus differing dramatically from the corresponding chains of the glyoxal, methylglyoxal and propylglyoxal analogs.

Biochemical characterization of propylglyoxal bis(guanylhydrazone). Facile synthesis of monoalkylglyoxal bis(guanylhydrazones).

Propylglyoxal bis(guanylhydrazone) sulfate, a novel analog of the well-known antileukemic drug methylglyoxal bis(guanylhydrazone), has been prepared from 2,2-dibromopentanal, and the compound has been characterized biochemically. Although it is a powerful inhibitor of S-adenosylmethionine decarboxylase, its Ki value (0.2 microM) is considerably higher than that of ethylglyoxal bis(guanylhydrazone) (0.06 microM). The compound is only poorly taken up by tumor cells, and its accumulation is not stimulated by a prior exposure of the tumor cells to difluoromethylornithine, a compound that causes polyamine depletion. Thus, the uptake characteristics of the compound are similar to those of ethylglyoxal bis(guanylhydrazone), but in striking contrast to those of methylglyoxal and glyoxal bis(guanylhydrazones). Since the configuration of the double bonds in glyoxal, methylglyoxal and propylglyoxal bis(guanylhydrazones) has been shown to be identical, the different uptake characteristics are probably only due to differences in side chain size and/or hydrophobicity.

[Synthesis and biological activity of 1,4-benzoquinone-guanylhydrazone-thiosemicarbazone analogs. 1. Substitution at the S atom]. / Zur Synthese und biologischen Wirksamkeit von Analogen des 1,4-Benzochinon-guanylhydrazon-thiosemicarbazons. 1. Mitteilung: Substitution am S-Atom.

The synthesis of S-substituted derivatives of 1,4-benzoquinone-guanylhydrazone-thiosemicarbazone is described. The obtained 1,4-benzoquinone-guanylhydrazone-S-alkyl (resp. aralkyl)-isothiosemicarbazones, in comparison with the unsubstituted standard compound, showed a significantly decreased biological activity against the murine leukemias L 1210 and P 388 as well as against the growth of several kinds of bacteria. Therefore the S-substitution seems not to be useful for reaching a maximum activity.

Trypanocidal 1,3-arylene diketone bis(guanylhydrazone)s. Structure-activity relationships among substituted and heterocyclic analogues.

Based on the antitrypanosomal activity of 1,3-diacetylbenzene bis(guanylhydrazone) (4) and 2,6-diacetylpyridine bis(guanylhydrazone) (17), a number of substituted and heterocyclic 1,3-arylene diketone bis(guanylhydrazone)s were prepared and tested against Trypanosoma brucei infections in mice. A wide range of ED50 values was observed among 5-substituted derivatives of 4. The 5-amino analogue 5 and 5-acetamido analogue 6 were about twice as active as 4. 1,3,5-Triacetylbenzene tris(guanylhydrazone) (12) was about 9 times as active as 4 and was approximately one-half as active as the currently used trypanocide diminazene aceturate in this test system. Other 5-derivatives had activity equivalent to or less than that of the parent compound 4. Three new heterocyclic analogues were all less active than 2,6-diacetylpyridine derivative 17 and benzene derivative 4. Ring substitution ortho to the guanylhydrazone side chains was invariably detrimental to activity. Side-chain homologues 1,3-dipentanoylbenzene bis(guanylhydrazone) and 1,3-diacetylbenzene bis(2-imidazolin-2-ylhydrazone) were essentially inactive.