Signal and Time Resolved Information Experiment (SATIRE): An NMR Supersequence for Monitoring Complex Environmental and Biological Processes without ¹³ C Enrichment

Complex NMR process monitoring often requires chemical shift dispersion afforded by 2D NMR and high temporal resolution of ¹H NMR in the same experiment. However, interleaving conventional 1D and 2D experiments leaves "time gaps" in each data set. This work presents the Signal And TIme Resolved information Experiment (SATIRE), an NMR supersequence that uses the leftover ¹H magnetization (98.9%) not used in the HSQC to collect ¹H NMR data within the same scan, using a single receiver. The approach is designed for those interested in monitoring complex systems that have a low signal-to-noise ratio (SNR). For example, if a researcher monitored living organisms for 24 h by ¹H NMR alone there may not be enough spectral dispersion for assignment. The low SNR would necessitate a long HSQC, potentially doubling the required NMR time. Conversely, with SATIRE the HSQC would be collected essentially for "free" at the same time as the ¹H data are collected. In SATIRE, the signal-to-noise ratios of the HSQC and ¹H are identical to the standalone experiments and are designed to permit relative quantitation in the ¹H data. Because the data are collected as a pseudo-3D experiment, it is also possible to extract individual shorter time scale HSQC or ¹H NMR spectra around time points of interest, SNR permitting. The approach is introduced and then demonstrated on benchtop NMR to monitor sucrose hydrolysis and finally at high field (500 MHz) to follow anoxic stress <i>in vivo</i>. In summary, SATIRE allows simultaneous acquisition of 1D and 2D NMR without compromising either data set and supports complex process monitoring in any application at natural abundance.