A Convenient Synthesis of Monocationic 1-[(Cyclic Amidino)methyl]thymines

Selective cytostatic and cytotoxic anticancer effects of bisfunctional agents: A strategy for the design of DNA binding agents

Various agents have been synthesized and proved useful for the National Cancer Institute's anticancer testing as potential new drugs, but most agents suffer side effects from their limited selectivity against cancer cells over healthy ones. Therefore, this paper attempts to describe drugs in terms of the level of tumor cell selectivity which they possess to define the features of molecules that are essential for useful cytotoxicity. Selected cyclic amidinothymine analogues (NSC 697864, NSC 697865, and NSC 697869) have nanomolar inhibitory activities against leukemia cell lines: CCRF-CEM, HL-60(TB), while bisfunctional cancer fighters NSC 702408 and NSC 702409, showing larger numbers of cytostatic and cytotoxic effects, in an extended conformation would probably adopt a similar to NSC 715653 conformation leaving both opposite H-bond donor groups at the same distance to interact with DNA in a similar way. Such specific interactions (cell line selectivity to unique mutated patterns) lower considerably the observed dose-response concentrations. This in vitro selectivity is shown to translate into in vivo efficacy indicated by the inflection in the cumulative testing curve.

The usefulness of cyclic diamidines with different core-substituents as antitumor agents

A series of related polycationic compounds has been screened for potential antitumor activity by the NCI's in vitro testing (one dose primary anticancer assay and the NCI-60 full panel screening). The GI50 values of triazines 3 and 4 are on average 1.9 microM and 2.4 microM, respectively. Furan 8 deserves mention too (1.9 microM). The biological test results showed that carbazole 10 possessed cytotoxic activity in the nanomolar range, much better than the other compounds tested, only against several cancer cell lines: CCRF-CEM, HL-60(TB), MOLT-4, NCI-H522, COLO 205, SF-268, but the average GI50 value was higher (15 microM). The activity appears closely dependent on the core-shape and length of the bisimidazoline molecules (important for both high cytotoxicity and DNA binding). The mechanism of DNA minor-groove binding of diamidines 1-12, based on the anticancer parameters, is highly probable.

Mild method for the conversion of amides to thioamides

Aqueous ammonium sulfide was found to be an ideal substitute for hydrogen sulfide for the thiolysis of activated amides. High yields of the corresponding thioamides were obtained for a broad range of substrates, using two different procedures that are both operationally simple and inexpensive, as well as amenable to large-scale preparation. Preliminary results indicate that aqueous ammonium sulfide may also replace hydrogen sulfide in the synthesis of thionoesters from amides.

Nonnucleoside HIV-1 reverse transcriptase inhibitors: Part I. Synthesis and structure-activity relationship of 1-alkoxymethyl-5-alkyl-6-naphthylmethyl uracils as HEPT analogues

1-alkoxymethyl-5-alkyl-6-naphthylmethyl uracils, which are novel 1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine (HEPT) analogues, were synthesized for evaluation as selective and potent nonnucleoside human immunodeficiency virus (HIV)-1 reverse transcriptase inhibitors. The anti-HIV-1 activity of these compounds was assayed in vitro using HIV-1 infected MT-4 and CEM bioassays. The EC50, CC50 and SI were recorded and calculated. The appropriate position, especially in the 1-position of the naphthyl ring, led to dramatic increases in potency, in both MT-4 and CEM cellular assays. The most important compounds in this series, 1-ethoxymethyl-5-isopropyl-6-(1-naphthylmethyl)thymine 8l (IC50=17 nM, CC50=38332 nM, SI=2229) and 1-benzyloxymethyl-5-ethyl-6-(1-naphthylmethyl)thymine 8n (IC50=17 nM, CC50=32560 nM, SI=1889) were significantly more potent than HEPT (EC50=7.0 microM, CD50=740 microM) in the anti-HIV-1 in vitro cellular assay.