Effect of A-Ring Modifications on the DNA-Binding Behavior and Cytotoxicity of Pyrrolo[2,1-c][1,4]benzodiazepines
| Autor: | Philip Wilson Howard, Barbara Cacciari, David E. Thurston, Leoni A, D. S. Bose, Andrea Guiotto, Pier Giovanni Baraldi, Kelland Lr, Rault S, Foloppe Mp, Jenkins Tc |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Diazine
Pyrimidine Stereochemistry Imine Pyrrolobenzodiazepine Antineoplastic Agents Ether DNA Nucleic Acid Denaturation Chemical synthesis Benzodiazepines Inhibitory Concentration 50 Mice Structure-Activity Relationship chemistry.chemical_compound chemistry Drug Discovery Pyridine Tumor Cells Cultured Animals Humans Molecular Medicine Cattle Anthramycin Drug Screening Assays Antitumor |
| Zdroj: | Journal of Medicinal Chemistry. 42:1951-1964 |
| ISSN: | 1520-4804 0022-2623 |
| Popis: | Several A-ring-modified analogues of the DNA-binding antitumor agent DC-81 (5) have been synthesized in order to study structure-reactivity/cytotoxicity relationships. For two molecules (23 and 30) the modifications required the addition of a fourth ring to give the novel dioxolo[4,5-h]- and dioxano[5,6-h]pyrrolo[2,1-c][1, 4]benzodiazepin-11-one (PBD) ring systems, respectively. Another three analogues (34, 38, and 48) have the native benzenoid A-ring replaced with pyridine, diazine, or pyrimidine rings to give the novel pyrrolo[2,1-c][1,4]pyridodiazepine, pyrrolo[2,1-c][1, 4]diazinodiazepine, and pyrrolo[2,1-c][1,4]pyrimidinodiazepine systems, respectively. The other new analogues (16a,b) have extended chains at the C8-position of the DC-81 structure. During the synthesis of these compounds, a novel tin-mediated regiospecific cleavage reaction of the dioxole intermediate 18 was discovered, leading to the previously unknown iso-DC-81 (20). In addition, an unusual simultaneous nitration-oxidation reaction of 4-(3-hydroxypropoxy)-3-methoxybenzoic acid (8) was found to produce 3-(4-carboxy-2-methoxy-5-nitrophenoxy)propanoic acid (9), a key intermediate, in high yield. In general, the results of cytotoxicity and DNA-binding studies indicated that none of the changes made to the A-ring of the PBD system significantly improved either binding affinity or cytotoxicity in comparison to DC-81. This result suggests that the superior potency of natural products such as anthramycin (1), tomaymycin (2), and sibiromycin (3) is due entirely to differences in C-ring structure, and in particular exo or endo unsaturation at the C2-position and C2-substituents containing unsaturation. This study also provided information regarding the influence of A-ring substitution pattern on the relative stability of the interconvertible N10-C11 carbinolamine, carbinolamine methyl ether, and imine forms of PBDs. |
| Databáze: | OpenAIRE |
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