20443-03-2

Synthetic ways to introduce functional groups (CO 2 Me, CO 2 H, OCH 2 CO 2 H, OCH 2 C≡CH, CH 2 OH, CH 2 Cl, CH 2 N 3) into the pyridine ring of pyridine-containing azacrown compounds are described. These groups were introduced at position-4 of the pyridine ring, while keeping the macrocyclic carboxylate groups available for metal chelation. The derivatives were obtained by macrocyclization reaction of 4-substituted, trimethyl pyridine-2,4,6-tricarboxylate or by modification of methyl ester group in pyridine fragment of macrocycles. Obtained derivatives can be applied for preparing radiotherapeutic agents by conjugation to different vector biomolecules for targeted drug delivery to cancer cells without damaging healthy tissue.

The mitochondrial DNA G-quadruplex (mtDNA G4) is a potential regulatory element for the regulation of mitochondrial functions; however, its relevance and specific roles in diseases remain largely unknown. Here, we engineered a set of chemical probes, incl

The invention belongs to the technical field of membrane separation, and more specifically relates to picolinamide oligomers, a preparation method and applications thereof. The picolinamide oligomerscomprise the following characteristics: 1. the oligomers

An "S3N-ligand azo-dye" conjugate has been synthesised with a view to the development of a sensor for heavy metal ions. Complexation of this system with Ag(i), Hg(ii) and Cu(ii) salts has been investigated and an X-ray structure has been obtained for a Hg(ii) complex. Complexation of the conjugated dye to these metals results in a bathochromic shift in the absorption maximum of the azo dye, an effect which is most pronounced for Cu(ii).

The reaction between 3,6,9-trithia-1(2,6)-pyridinacyclodecaphane and representative group 10 and 11 metal salts [Cu(NO3)2, NiCl2 or Ag(CF3CO2)] afforded 1:1 complexes, which in the case of CuII and AgI were characterised by single-crystal X-ray crystallography. The catalytic activity of these complexes in A3-coupling reactions between aldehydes, terminal alkynes and amines was assessed in both protic (water) and aprotic (toluene) media. These A3-reactions prove to be more efficient, proceed with lower catalyst loadings and with faster reaction rates, when conducted in a focused microwave reactor as compared to the same reactions promoted by standard, thermal, modes of activation.

The invention provides Pyridostatin compounds, and a preparation method and application thereof. The structural formula of the Pyridostatin compounds is disclosed as Formula I. The compounds and pharmaceutically acceptable salts thereof have favorable antitumor activity for human lung cancer and human colon cancer.

The G-quadruplexes located in the P1 promoter of B-cell lymphoma-2 (Bcl-2) gene are implicated to regulate Bcl-2 expression. Here, we designed a new pyridostatin analog named PDF, which exhibited high specificity and stabilizing effect toward G-quadruplexes. The luciferase assay demonstrated that PDF could significantly suppress Bcl-2 transcriptional activation in human laryngeal squamous carcinoma cells (Hep-2) cells. Besides, PDF also induced cell apoptosis in vitro assays. These results provide an excellent G-quadruplex specific ligand as an efficient Bcl-2 inhibitor. These results also implicate that PDF may be a potential anticancer drug to head neck cancer.

G-quadruplex as a therapeutic target to develop novel anti-cancer agents has attracted a growing interest. Among all the ligands of G-quadruplexes, pyridostatin derivatives play a very important role. Here, we first reported the recognition of the fundamental skeleton pyridostatin I, which was simply synthesized. Compared to pyridostatin II comprising terminal amino groups, pyridostatin I selectively stabilized intramolecular anti-parallel telomeric G-quadruplex by raising the melting temperature about 20 °C at 295 nm of H22, while pyridostatin II preferred to stabilize intermolecular parallel telomeric G-quadruplex by raising the melting temperature about 25 °C at 265 nm of H7, maybe due to the suited size measurements between G-quadruplex hosts and pyridostatin guests. MTT assays indicated that pyridostatin II had better cytotoxic effects against HCT-8 and A549 cell lines obviously, indicating positively charged side chains may be required for improving the water solubility and cellular uptake of the apolar central skeleton.

We have previously reported potent substrate-based pentapeptidic BACE1 inhibitors possessing a hydroxymethylcarbonyl isostere as a substrate transition-state mimic. While these inhibitors exhibited potent activities in enzymatic and cellular assays (KMI-4

We describe a novel synthetic small molecule which shows an unprecedented stabilization of the human telomeric G-quadruplex with high selectivity relative to double-stranded DNA. We report that this compound can be used in vitro to inhibit telomerase activity and to uncap human POT1 (protection of telomeres 1) from the telomeric G-overhang. We also show that the small molecule G-quadruplex binder induces a partial alteration of shelterin through POT1 uncapping from telomeres in human HT1080 cancer cells and the presence of γH2AX foci colocalized at telomeres. Copyright

Bis-tetraazamacrocycles such as the bicyclam AMD3100 are a class of potent and selective anti-HIV-1 and HIV-2 agents that inhibit virus replication by binding to the chemokine receptor CXCR4, the co-receptor for entry of X4 viruses. With the aim of optimi

A series of macrocyclic polyether-diester ligands containing a proton-ionizable 4-hydroxypyridine subcyclic unit has been prepared.These new macrocyclic ligands form stable complexes with both alkylammonium perchlorate salts and with alkylamines.The crystal structure for one of these complexes with an alkylamine shows that the hydroxy proton has been donated to the amine with the resultant formation of a 4-pyridone unit.Chiral dimethyl- and diphenyl-substituted macrocycles containing the 4-hydroxypyridine subcyclic unit exhibit chiral recognition for the enantiomers of 2-(1-naphthyl)ethylamine and their hydrogen perchlorate salts.