95034-05-2Relevant articles and documents
Gem-dimethyl peptide nucleic acid (α/β/γ-gdm-PNA) monomers: synthesis and the role ofgdm-substituents in preferential stabilisation ofZ/E-rotamers
Datta, Dhrubajyoti,Ganesh, Krishna,Kulkarni, Pradnya,Ramabhadran, Raghunath O.
, p. 6534 - 6545 (2021/08/03)
The flexible backbone of aminoethylglycine (aeg) PNA upon substitution becomes sterically constrained to enable conformational pre-organization for preferential binding to DNA or RNA. The bulkygem-dimethyl (gdm) substituent on carbons adjacent to thet-amide sidechain either at Cα (glycyl) or Cβ/Cγ (aminoethylene) sides may influence theZ/Erotamer ratio arising from a restricted rotation around thet-amide bond. Employing 2D NMR (NOESY), it is shown here that the Cα-gdm-PNA-T monomer exhibits exclusively theZ-rotamer, while the Cβ-gdm-PNA-T monomer shows only theE-rotamer. The unsubstitutedaeg-PNA-T and Cγ-gdm-PNA-T monomers display a mixture ofZ/Erotamers. The rotamers witht-amide carbonyl pointing towards thegem-dimethyl group always prevailed. The results are supported by computational studies that suggested that the preferred rotamers are the outcome of a net energetic benefit from the stabilising n-π* interactions of carbonyls (amide backbone andt-amide sidechain), and C-H?O interactions and the destabilising steric clash ofgem-dimethyl groups with the t-amido methylene group. TheE-rotamer structure in Cγ-gdmis also characterised by X-ray crystallography. The exclusiveE-rotamer for the Cβ-gdmmonomer seen in solution here is the first such example among several modified PNA monomers. Since the conformation of the sidechain is important for inducing base stacking and effective base pairing, the exclusiveE-rotamer in the Cβ-gdmmonomer may have significance in the properties of the derived PNA?:?DNA/RNA duplexes with allE-rotamers.
NITROGENOUS HETEROCYCLIC COMPOUND, PREPARATION METHOD, INTERMEDIATE, COMPOSITION AND USE
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Paragraph 0192, (2019/01/17)
Disclosed are a nitrogenous heterocyclic compound, intermediates, a preparation method, a composition and use thereof. The nitrogenous heterocyclic compound in the present invention is as shown in formula I. The compound has a high inhibitory activity towards ErbB2 tyrosine kinase and a relatively good inhibitory activity towards human breast cancer BT-474 and human gastric cancer cell NCI-N87 which express ErbB2 at a high level, and at the same time has a relatively weak inhibitory activity towards EGFR kinase. Namely, the compound is a highly selective small-molecule inhibitor targeted at ErbB2, and hence it has a high degree of safety, and can effectively enlarge the safety window in the process of taking the drug.
AN ADVANTAGEOUS PROCESS FOR PREPARING ANAGLIPTIN AND ITS NOVEL CRYSTALLINE FORM-H
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Page/Page column 14, (2016/12/22)
The present invention discloses the process for preparation of Anagliptin and its novel crystalline form-H.