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Updated: Sep 15, 2025

2D-HELS MS Seq: A General LC-MS-Based Method for Direct and de novo Sequencing of RNA Mixtures with Different Nucleotide Modifications
05:41

2D-HELS MS Seq: A General LC-MS-Based Method for Direct and de novo Sequencing of RNA Mixtures with Different Nucleotide Modifications

Published on: July 10, 2020

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在反意义寡核酸中区分n-1定位异构体,使用正交的LCMS方法

Zifan Li1, Xiaoqing Kong1, Xiao Zhou1

  • 1Pharmaceutical Operations & Technology, Biogen, 225 Binney Street, Cambridge, Massachusetts 02142, United States.

Journal of the American Society for Mass Spectrometry
|July 16, 2025
PubMed
概括

鉴定治疗性寡核酸合成中的关键杂质是关键. 我们开发了方法来区分和量化NMA PS ASO中的特定删除杂质 (n-NMA 5-甲基细胞素),改善质量控制.

关键词:
脱硫处理是一种脱硫的方法.杂质杂质是一种杂质.这是一种寡核化物.位置性异构体的位置性异构体.双联质谱质量测量技术

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Stereoisomerism

Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
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¹H NMR Chemical Shift Equivalence: Enantiotopic and Diastereotopic Protons

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In chiral compounds such as 2-butanol, replacing the methylene hydrogens at C3 produces a pair of...
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Protons in identical electronic environments within a molecule are chemically equivalent and have the same chemical shift. The replacement test is a useful tool to identify chemical equivalence and predict NMR spectra. A substituent replaces each of the protons being examined and the resulting molecules are compared. If the same molecule is obtained, the protons are equivalent or homotopic. Replacement of any hydrogens in ethane by chlorine yields chloroethane because all six protons are...
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Stereoisomers

On the basis of mirror symmetry, stereoisomers of an organic molecule can be further classified into diastereomers and enantiomers. Diastereomers are stereoisomers that are not mirror images of each other. Substituted alkenes, such as the cis and trans isomers of 2-butene, are diastereomers, as these molecules exhibit different spatial orientations of their constituent atoms, are not mirror images of each other, and do not interconvert. Here, the interconversion is suppressed due to...
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Naming Enantiomers

The naming of enantiomers employs the Cahn–Ingold–Prelog rules that involve assigning priorities to different substituent groups at a chiral center. Each enantiomer, being a distinct molecule, is assigned a unique name by the Cahn–Ingold–Prelog (CIP) rules, also called the R–S system. The prefix R- or S- attached to the chiral centers in an enantiomer is dependent on the spatial arrangement of the four substituents on the chiral center. The R–S system...
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Stereoisomerism of Cyclic Compounds

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