Protochlorophyllide Reductase III: Synthesis of a Protochlorophyllide-Dihydroflavin Complex
摘要:
Abstract— A mild and efficient method of linking a dihydroflavin to the C‐17 carboxylic acid side chain of protochlorophyllide, without degradation of the sensitive E ring or loss of magnesium, is described. The appended dihydroflavin was shown to quench the fluorescence of protochlorophyllide. In contrast, a dihydronicotinamide moiety was unable to effect fluorescence quenching. The relevance of these findings to a possible mechanism of action of the enzyme protochlorophyllide reductase is discussed.
Synthesis of substituted uracils by the reactions of halouracils with selenium, sulfur, oxygen and nitrogen nucleophiles under focused microwave irradiation
Undermicrowaveirradiation, the nucleophilic substitutionreactions of halouracils with selenium, sulfur, oxygen and nitrogen nucleophiles was complete within several minutes with yields up to 99%. The method using microwaveirradiation is superior to those conducted under conventional heating processes.
Inhibitors of Bacillus subtilis DNA polymerase III. Influence of modifications in the pyrimidine ring of anilino- and (benzylamino)pyrimidines
作者:Debra J. Trantolo、George E. Wright、Neal C. Brown
DOI:10.1021/jm00155a016
日期:1986.5
examined in several series of N6-substituted 6-aminopyrimidines. The presence of alkyl groups as large as n-butyl in the 3-position of 6-(5-indanylamino)uracil had no effect on inhibitor-enzyme binding. Substituents in the 4-position of a series of 2-amino-6-(benzylamino)pyrimidines had complex effects: alkoxy and phenoxy derivatives were less active than the parent 4-oxo (isocytosine) compound, but alkylphenoxy
Toxoflavins and Deazaflavins as the First Reported Selective Small Molecule Inhibitors of Tyrosyl-DNA Phosphodiesterase II
作者:Ali Raoof、Paul Depledge、Niall M. Hamilton、Nicola S. Hamilton、James R. Hitchin、Gemma V. Hopkins、Allan M. Jordan、Laura A. Maguire、Alison E. McGonagle、Daniel P. Mould、Mathew Rushbrooke、Helen F. Small、Kate M. Smith、Graeme J. Thomson、Fabrice Turlais、Ian D. Waddell、Bohdan Waszkowycz、Amanda J. Watson、Donald J. Ogilvie
DOI:10.1021/jm400568p
日期:2013.8.22
The recently discovered enzyme tyrosyl-DNA phosphodiesterase 2 (TDP2) has been implicated in the topoisomerase-mediated repair of DNA damage. In the clinical setting, it has been hypothesized that TDP2 may mediate drug resistance to topoisomerase II (topo II) inhibition by etoposide. Therefore, selective pharmacological inhibition of TDP2 is proposed as a novel approach to overcome intrinsic or acquired resistance to topo II-targeted drug therapy. Following a high-throughput screening (HTS) campaign, toxoflavins and deazaflavins were identified as the first reported sub-micromolar and selective inhibitors of this enzyme. Toxoflavin derivatives appeared to exhibit a clear structure-activity relationship (SAP.) for TDP2 enzymatic inhibition. However, we observed a key redox liability of this series, and this, alongside early in vitro drug metabolism and pharmacokinetics (DMPK) issues, precluded further exploration. The deazaflavins were developed from a singleton HTS hit. This series showed distinct SAR and did not display redox activity; however low cell permeability proved to be a challenge.
Annulation of 6-aminouracils with 2,3-dimethoxy- and 2-fluorobenzaldehydes and 2-chloro-7-methoxyquinoline-3-carbaldehyde
作者:R. G. Melik-Ohanjanyan、T. R. Hovsepyan、S. G. Israelyan、G. S. Karakhanyan、N. S. Minasyan
DOI:10.1134/s1070428015100152
日期:2015.10
6-R-Aminouracils reacted with 2,3-dimethoxybenzaldehyde to give 10-R-substituted 9-methoxy-5-deazaflavins. No expected 5-deazaflavins were obtained in analogous reactions of 2,3-dimethoxybenzaldehyde with 6-aminouracil hydrochlorides. On the other hand, the corresponding 5-deazaflavin and naphthyridine hydrochlorides were formed in the reactions of 6-aminouracil hydrochlorides with 2-fluorobenzaldehyde and 2-chloro-7-methoxyquinoline-3-carbaldehyde. The newly synthesized 9,10-substituted 5-deazaflavins and benzo[b]pyrimido[5,4-g][1,8]naphthyridines attract interest as potential biologically active substances and substrates for further structural modifications.
New Synthesis and Biologically Active Molecular Design of Deazapteridine-Steroid Hybrid Compounds
This paper describes a facile and general synthesis of a new class of the hybrid compounds (4, 5 and 16), possessing 5-deazapteridine and steroid in the same ring system, by condensation of 6-(monosubstituted amino)uracils (9) or 6-(monosubstituted amino)-2-phenylpyrimidin-4(3H)-ones (14) with 2-hydroxymethyleneandrostanolone (10) or 2-hydroxymethylenetestosterone (15) under heating in the presence of p-toluenesulfonic acid monohydrate and their potential unti-coccidiosis activities.