title: Novel dihydrofolate reductase inhibitors. Structure-based versus diversity-based library design and high-throughput synthesis and screening.
abstract: Novel 2,4-diaminopyrimidines bearing N,N-disubstituted aminomethyl residues at the 5-position were designed as dihydrofolate reductase (DHFR) inhibitors. These compounds were obtained by treatment of 1-[(2,4-diamino-5-pyrimidinyl)methyl]pyridinium bromide with secondary amines in a polar solvent and in the presence of triethylamine at room temperature. The procedure was found to be very efficient and suitable for application in high-throughput synthesis. In addition, we found that high-throughput screening for enzymatic and in vitro antibacterial activity could be performed on crude reaction mixtures, thus avoiding any purification step. Over 1200 proprietary secondary amines were selected for high-throughput synthesis, based on structural and diversity-related criteria, and the resulting products were submitted to high-throughput screening. A greater number of hits, and significantly more active compounds, were obtained through structure-based library design than through diversity-based library design. Different classes of inhibitors of DHFR were identified in this way, including compounds derived from di-, tri-, and tetracyclic amines. In general, these products showed high activity against the enzymes derived from both TMP-sensitive and TMP-resistant Streptococcus pneumoniae. Some compounds possessed appreciable selectivity for the bacterial over the human enzyme, whereas other compounds were not at all selective. In most cases, active enzyme inhibitors also displayed antibacterial activity.
authors.affiliation: Preclinical Research, F. Hoffmann-La Roche Ltd., CH-4070 Basle, Switzerland. pierre.wyss@morphochem.ch
authors.forename: Pierre C
authors.initials: PC
authors.lastname: Wyss
authors.forename: Paul
authors.initials: P
authors.lastname: Gerber
authors.forename: Peter G
authors.initials: PG
authors.lastname: Hartman
authors.forename: Christian
authors.initials: C
authors.lastname: Hubschwerlen
authors.forename: Hans
authors.initials: H
authors.lastname: Locher
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Marty
authors.forename: Martin
authors.initials: M
authors.lastname: Stahl
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D020650:Combinatorial Chemistry Techniques; D018360:Crystallography, X-Ray; D024881:Drug Resistance, Bacterial; D005493:Folic Acid Antagonists / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011743:Pyrimidines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects; D013296:Streptococcus pneumoniae / Q000187:drug effects; D013329:Structure-Activity Relationship; D013762:Tetrahydrofolate Dehydrogenase / Q000737:chemistry* / Q000378:metabolism; D014295:Trimethoprim / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D005493:Folic Acid Antagonists; D011725:Pyridines; D011743:Pyrimidines; D014295:Trimethoprim; D013762:Tetrahydrofolate Dehydrogenase