MedChemExpress (MCE) - Stable Isotope-labeled Compounds

Different kinds of isotope atoms | High isotopic enrichment

Isotope-labeled compounds are chemical substances in which some atoms in their molecules are replaced by isotope atoms. MCE isotope-labeled compounds are all stable, and thus are non-radioactive. Stable Isotope-Labeled Compounds are mainly a series of labeled compounds which contains deuterium (2H, D), carbon-13 (13C), nitrogen-15 (15N), oxygen-18 (18O), etc. These compounds are excellent tools for identifying and understanding tracers, biological and chemical processes, for quantitative analysis, to explore metabolic pathways, to improve drug pharmacokinetics etc.

About Isotope-Labelling of Compounds...

Isotopes of hydrogen

MCE 1H, 2H and 3H Isotope labelled compounds

Isotopes are atoms of an element that have the same number of protons but different numbers of neutrons, giving them slightly different weights. Hydrogen has three isotopes: hydrogen (1H), deuterium (2H), tritium (3H), all of which contains 1 proton, but each contains 0, 1, and 2 neutrons and its atomic mass is 1, 2, 3 respectively. Deuterium (2H) is a stable isotope atom of hydrogen (1H) whereas tritium (3H) is a radioactive isotope. 

Isotope labelling of Sorafenib

Isotope labelling: Sorafenib

The chemical behaviour of a compound labeled with stable isotopes is usually indistinguishable from that of the parent. For example, in Donafenib (Sorafenib-d3), the three hydrogens on the methyl group were replaced by deuterium, and clinical trial indicated that Donafenib (Sorafenib-d3) has a favourable safety profile and notable anti-cancer efficacy for treating advanced hepatocellular carcinoma than Sorafenib.

Competitive Advantages of MCE Stable Isotope-Labeled Compounds

  • Different kind of Isotope Atoms: 2H (D), 13C, 15N, 17O & 18O, 34S, 10B
  • High Isotopic Enrichement: >98%
  • High Purity: >98%
  • Novel / Unique Isotope Labeled Compounds
  • > 6000 Isotope-labelled compounds available
  • Customization

Applications of Stable Isotope-Labeled Compounds

Pharmaceutical Research

In theory, incorporating „heavy hydrogen“ into small molecules improves hal-life of a drug and its toxicity profile. For example, Deutetrabenazine (Austedo®) is the world’s first deuterated drug, for the treatment of Huntington’s-disease-related movement disorders. Compared to tetrabenazine, Deutetrabenazine has a unique pharmacokinetic profile with more consistent systemic exposure, less frequent dosing and a potentially more favorable safety / tolerability profile.

  • Optimization of the pharmacokinetic properties
  • Reduction of toxicity
  • Increase in bioactivity
  • Reduction of epimerization
  • Mechanism of action
  • PET tracers
Isotope-labeled compounds for DrugDesign

Metabolic Research

Stable isotope labeling is an effective method for identifying drug metabolites because it can retain the physical and chemical properties and are easily detected by mass spectrometry. Jixia Yang et al. used 13C and 15N isotope labeled indolinone derivatives which successfully detected seven metabolites by UPLC/Q TOF MS in metabolic studies performed in hepatocytes, providing the important information to develop alpha-synuclein aggregate inhibitors.


Mass spectrometry ( MS )-based quantitative proteomic methods employ stable isotope-labeling to introduce signature mass tags to proteins that can be used by a mass spectrometer to quantify each analyte.


Using Tetraplex Stable-Isotope Coded Tags in mass spectrometric glycomics, and differentiating glycan structural isomers based on the tandem mass spectra of each composition using nanospray ionization, Michael J. Bowman et al. demonstrated the value of the tetraplex stable isotope tagging approach for producing high-quality glycomics, compositional profiling and fine structure analysis.

Standards for Environmental Analysis

PCBs and PBDEs are well-known man-made organohalogen compounds as environmental pollutants. Chenchen Huang et al. developed a compound-specific (Cl/Br-CSIA) using the GC-qMS method for the detection of PCBs and PBDEs, which are toxic to human health and are frequently detected in various abiotic and biotic media. It is also a promising tool for assessing the sources and transformation processes of PCBs and PDBEs in the environment.

Clinical Research

Advances in mass spectrometry ( MS )-based disease biomarker discoveries are continuously expanding the clinical diagnostics landscape. An important advantage of using stable isotopes is that these tracers are not radioactivity (such as the 13C urea breath test).

Biomolecular NMR

The advent of multidimensional (2D-4D) NMR, together with the widespread use of uniform isotopic labeling of proteins and RNA with the NMR-active isotopes, 15N and 13C, opened the door to detailed analysis of macromolecular structure, dynamics, and interactions of smaller macromolecules (<~25 kDa).

Trace Element Analysis

Linards Klavins et al. studied the trace element concentration and stable isotope ratio analysis in blueberries and bilberries across the world; the results demonstrated the detectable differences between macro- and microelement values in bilberries. This method could be utilized as an authenticity testing tool for berry origins.

Isotope-labeled compounds for Trace Analysis

Trace Element Analysis. Light stable element isotope (g13C,g15Ng18O) ratio values in blueberries from different countries.

Available isotope-labeled compounds for different research area

According to the functional groups and functions in stable isotope labeled compounds,  there are different applications in research area