DNA-Directed Alkylating Agents. 7. Synthesis, DNA Interaction, and Antitumor Activity of Bis(hydroxymethyl)- and Bis(carbamate)-Substituted Pyrrolizines and Imidazoles

• Published in: Journal of medicinal chemistry Vol. 41; no. 24; pp. 4744 - 4754
• Main Authors: Atwell, Graham J, Fan, Jun-Yao, Tan, Karin, Denny, William A
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 19.11.1998; Amer Chemical Soc
• Subjects: Alkylation; Animals; Antineoplastic agents; Antineoplastic Agents, Alkylating - chemical synthesis; Antineoplastic Agents, Alkylating - chemistry; Antineoplastic Agents, Alkylating - metabolism; Antineoplastic Agents, Alkylating - pharmacology; Base Sequence; Biological and medical sciences; Carbamates - chemical synthesis; Carbamates - chemistry; Carbamates - metabolism; Carbamates - pharmacology; Chemistry, Medicinal; Cross-Linking Reagents - chemical synthesis; Cross-Linking Reagents - chemistry; Cross-Linking Reagents - metabolism; Cross-Linking Reagents - pharmacology; DNA - chemistry; DNA - metabolism; DNA Primers; DNA, Superhelical - chemistry; DNA, Superhelical - metabolism; Drug Screening Assays, Antitumor; Electrophoresis, Agar Gel; General aspects; imidazoles; Imidazoles - chemical synthesis; Imidazoles - chemistry; Imidazoles - metabolism; Imidazoles - pharmacology; Kinetics; Leukemia P388 - pathology; Life Sciences & Biomedicine; Medical sciences; Molecular Sequence Data; Pharmacology & Pharmacy; Pharmacology. Drug treatments; Polymerase Chain Reaction; Pyrroles - chemical synthesis; Pyrroles - chemistry; Pyrroles - metabolism; Pyrroles - pharmacology; pyrrolizines; Science & Technology; Structure-Activity Relationship; Tumor Cells, Cultured; DEOXYRIBONUCLEIC-ACID; DESIGN; CARMETHIZOLE HYDROCHLORIDE; LIGANDS; SEQUENCE SPECIFICITY; ANALOGS; NITROGEN-MUSTARD; REACTIVITY; TARGETED ANILINE MUSTARD; BINDING; Antineoplastic agent; Nitrogen heterocycle; Acridine derivatives; P388-Leukemia; Cytotoxicity; Molecular interaction; Crosslink agent; Organic carbamate; Structure activity relation; Established cell line; Bicyclic compound; Aromatic compound; Mechanism of action; Chemical synthesis; Tumor cell; Sequence specificity; Minor groove; Benzene derivatives; Quinoline derivatives; Tricyclic compound; In vitro; Primary alcohol; Alkylating agent; Biological fixation; DNA; Benzamide derivatives
• ISSN: 0022-2623; 1520-4804
• DOI: 10.1021/jm9803119

A series of bis(hydroxymethyl)-substituted imidazoles, thioimidazoles, and pyrrolizines and related bis(carbamates), linked to either 9-anilinoacridine (intercalating) or 4-(4-quinolinylamino)benzamide (minor groove binding) carriers, were synthesized and evaluated for sequence-specific DNA alkylation and cytotoxicity. The imidazole and thioimidazole analogues were prepared by initial synthesis of [(4-aminophenyl)alkyl]imidazole-, thioimidazole-, or pyrrolizine dicarboxylates, coupling of these with the desired carrier, and reduction to give the required bis(hydroxymethyl) alkylating moiety. The pyrrolizines were the most reactive alkylators, followed by the thioimidazoles, while the imidazoles were unreactive. The pyrrolizines and some of the thioimidazoles cross-linked DNA, as measured by agarose gel electrophoresis. Strand cleavage assays showed that none of the compounds reacted at purine N7 or N3 sites in the gpt region of the plasmid gpt2Eco, but the polymerase stop assay showed patterns of G-alkylation in C-rich regions. The corresponding thioimidazole bis(carbamates) were more selective than the bis(hydroxymethyl) pyrrolizines, with high-intensity bands at 5‘-NC*C*N, 5‘-NGC*N and 5‘-NC*GN sequences in the PCR stopping assay (* indicates block sites). The data suggest that these targeted compounds, like the known thioimidazole bis(carbamate) carmethizole, alkylate exclusively at guanine residues via the 2-amino group, with little or no alkylation at N3 and N7 guanine or adenine sites. The cytotoxicities of the compounds correlated broadly with their reactivities, with the bis(hydroxymethyl)imidazoles being the least cytotoxic (IC50s >1 μM; P388 leukemia) and with the intercalator-linked analogues being more cytotoxic than the corresponding minor-groove-targeted ones. This was true also for the more reactive thioimidazole bis(carbamates) (IC50s 0.8 and 11 μM, respectively), but both were more active than the analogous “untargeted” carmethizole (IC50 20 μM). The bis(hydroxymethyl)pyrrolizine analogues were the most cytotoxic, with IC50s as low as 0.03 μM.