An overview is presented of gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS), the two major hyphenated techniques employed in metabolic profiling that complement direct 'fingerprinting' methods such as atmospheric pressure ionization (API) quadrupole time-of-flight MS, API Fourier transform MS, and NMR. In GC/MS, the analytes are normally derivatized prior to analysis in order to reduce their polarity and facilitate chromatographic separation. The electron ionization mass spectra obtained are reproducible and suitable for library matching, mass spectral collections being readily available. In LC/MS, derivatization and library matching are at an early stage of development and mini-reviews are provided. Chemical derivatization can dramatically increase the sensitivity and specificity of LC/MS methods for less polar compounds and provides additional structural information. The potential of derivatization for metabolic profiling in LC/MS is demonstrated by the enhanced analysis of plant extracts, including the potential to measure volatile acids such as formic acid, difficult to achieve by GC/MS. The important role of mass spectral library creation and usage in these techniques is discussed and illustrated by examples.
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http://dx.doi.org/10.1093/jxb/eri069 | DOI Listing |
Nat Comput Sci
January 2025
AI for Science (AI4S)-Preferred Program, Peking University Shenzhen Graduate School, Shenzhen, China.
Electronic circular dichroism (ECD) spectra contain key information about molecular chirality by discriminating the absolute configurations of chiral molecules, which is crucial in asymmetric organic synthesis and the drug industry. However, existing predictive approaches lack the consideration of ECD spectra owing to the data scarcity and the limited interpretability to achieve trustworthy prediction. Here we establish a large-scale dataset for chiral molecular ECD spectra and propose ECDFormer for accurate and interpretable ECD spectrum prediction.
View Article and Find Full Text PDFJ Am Soc Mass Spectrom
January 2025
Mass Spectrometry Data Center, Biomolecular Measurement Division, National Institute of Standards and Technology (NIST), Gaithersburg, Maryland, 20899, United States.
PLoS One
January 2025
School of Information and Technology, Wenzhou Business College, Wenzhou, Zhejiang, China.
Liver cancer is the sixth most frequent malignancy and the fourth major cause of deaths worldwide. The current treatments are only effective in early stages of cancer. To overcome the therapeutic challenges and exploration of immunotherapeutic options, broad spectral therapeutic vaccines could have significant impact.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Emory University School of Medicine, Atlanta, GA, USA.
Background: The microtubule-associated Tau gene (MAPT) undergoes alternative splicing to produce isoforms with varying combinations of microtubule-binding region (MTBR) repeats (3R, 4R). The MTBR is the predominant region that forms paired helical filaments and neurofibrillary tangles fibrils in disease. Alzheimer's disease (AD) is a mixed Tauopathy containing both 3R and 4R isoforms.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
University of California San Francisco, San Francisco, CA, USA.
Background: Neural circuit hyperexcitability and impaired excitation-to-inhibition (E/I) activity is believed to be a key contributor to synaptic and network degeneration in Alzheimer's disease (AD). Extensive preclinical research on transgenic animal models of AD have demonstrated neuronal and circuit level E/I imbalance mediated by amyloid-beta (Aβ) and tau proteins. Synaptic and network deficits are also integral changes of aging.
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