Leveraging the HMBC to Facilitate Metabolite Identification

Authors

Fatema Bhinderwala, University of Nebraska - Lincoln, University of Pittsburgh School of MedicineFollow
Thao Vu, University of Nebraska-Lincoln, Colorado School of Public Health
Thomas G. Smith, University of Nebraska-Lincoln
Julian Kosacki, University of Nebraska-Lincoln
Darrell D. Marshall, University of Nebraska-Lincoln
Yuhang Xu, University of Nebraska-Lincoln, Bowling Green State University
Martha D. Morton, University of Nebraska–LincolnFollow
Robert Powers, University of Nebraska - LincolnFollow

Document Type

Article

Date of this Version

3-18-2024

Citation

Anal Chem. 2022 November 29; 94(47): 16308–16318. doi:10.1021/acs.analchem.2c02902.

Comments

HHS Public Access.

Abstract

The accuracy and ease of metabolite assignments from a complex mixture are expected to be facilitated by employing a multi-spectral approach. The 2D ¹H-¹³C HSQC and 2D ¹H-¹H-TOCSY are the experiments commonly used for metabolite assignments. The 2D ¹H-¹³C HSQC-TOCSY and 2D ¹H-¹³C HMBC are routinely used by natural products chemists but have seen minimal usage in metabolomics despite the unique information, the nearly complete ¹H-¹H and ¹H-¹³C and spin systems provided by these experiments that may improve the accuracy and reliability of metabolite assignments. The use of a ¹³C-labeled feed stock such as glucose is a routine practice in metabolomics to improve sensitivity and to emphasize the detection of specific metabolites but causes severe artifacts and an increase in spectral complexity in the HMBC experiment. To address this issue, the standard HMBC pulse sequence was modified to include carbon decoupling. Non-uniform sampling was also employed for rapid data collection. A dataset of reference 2D ¹H-¹³C HMBC spectra were collected for 94 common metabolites. ¹³C-¹³C spin connectivity was then obtained by generating a covariance pseudo-spectrum from the carbon-decoupled HMBC and the