Formation and Reactions of N7-Aminoguanosine and Derivatives
摘要:
Arylamines are mutagens and carcinogens and are thought to initiate tumors by forming adducts with DNA. The major adducts are C-8-guanyl, and we have previously suggested a role for guanyl-N-7 intermediates in the formation process. N-7-Aminoguanosine (Guo) was synthesized and characterized, with the position of the NH2 at N7 established by two-dimensional rotating frame Overhauser enhancement NMR spectroscopy. In DMF, N-7-NH(2)Guo formed C-8-NH(2)Guo and the cyclic product C-8:5'-O-cycloGuo. In aqueous media, these products were formed along with 8-oxo-7,8-dihydroGuo, N-7-NH(2)guanine, and a product characterized as a purine 8,9-ring-opened derivative (N-aminoformamidopyrimidine). The rate of aqueous decomposition of N-7-NH(2)Guo increased with pH, with a t(1/2) of 10 h at pH 7 and a t(1/2) of 2 h at pH 9. The rate of migration of NH2 from N7 to C8 is fast enough to explain the formation of C-8-NH(2)Guo from the reaction of 2,4-dinitrophenoxyamine with Guo but not the formation of C-8-(arylamino)Guo in the reaction of Guo with aryl hydroxylamine esters; however, the fluorenyl moiety may facilitate the proposed rearrangement by stabilizing an incipient negative charge in the transfer. In the reaction of Guo with N-hydroxy-2-aminofluorene and acetylsalicylic acid, a peak with the mass spectrum expected for N-7-(2-aminofluorenyl)Guo was detected early in the reaction and was distinguished from C-8-(2-aminofluorenyl)Guo. NMR experiments with [8-C-13]Guo also provided some additional support for transient formation of N-7-(2-aminofluorenyl)Guo. We conclude that a guanyl-N-7 intermediate is reasonable in the reaction of activated arylamines with nucleic acids, although an exact rate of transfer of an N-7-arylamine group to the C8 position has not yet been quantified. The results provide an explanation for the numerous products associated with modification of DNA by activate arylamines. However, the contribution of "direct" reaction at the guanine C8 atom cannot be excluded.
Heterocyclic GTP Cyclohydrolase 1 Inhibitors For the Treatment of Pain
申请人:Blagg Julian
公开号:US20120252791A1
公开(公告)日:2012-10-04
The present invention relates to the field of small molecule heterocyclic inhibitors of GTP cyclohydrolase (GCH-I), or a tautomer, prodrug, or pharmaceutically acceptable salt thereof. The invention also features pharmaceutical compositions of the compounds and the medical use of these compounds for the treatment or prevention of pain (e.g., inflammatory pain, nociceptive pain, functional pain, or neuropathic pain).
US8912318B2
申请人:——
公开号:US8912318B2
公开(公告)日:2014-12-16
[EN] CELL PENETRATING PEPTIDE INHIBITORS OF P53-MDM2 INTERACTION<br/>[FR] INHIBITEURS PEPTIDIQUES DE PÉNÉTRATION CELLULAIRE DE L'INTERACTION P53-MDM2
申请人:SORRENTO THERAPEUTICS INC
公开号:WO2018138673A1
公开(公告)日:2018-08-02
Provided are compounds having the Formula I or II: (I); or (II); and pharmaceutically acceptable salts thereof, pharmaceutical compositions thereof, and their use in the treatment of cancers.