Relayed hyperpolarization from para-hydrogen improves the NMR detectability of alcohols

Abstract

NMR signal strength improvements delivered through hyperpolarisation via para-hydrogen enable the facile detection of alcohols.

Optimisation of pyruvate hyperpolarisation using SABRE by tuning the active magnetisation transfer catalyst

“…Many studies have varied the temperature to achieve a substrate exchange rate optimum for SABRE magnetisation transfer. 34,41,60 To this end, solutions of 1a, 6 equivalents of sodium pyruvate-1,2-[ 13 C 2 ], and 4 equivalents of the sulfoxides I-III, IV-VII, shown in Fig. 3, were shaken with 3 bar p-H 2 in methanol-d 4 at three different temperatures.…”

“…39 A related technique, SABRE-Relay, has allowed the hyperpolarisation of a wide range of non-ligating substrates that contain functional groups which can receive hyperpolarised protons through exchange from a suitable carrier. 40,41 When applied to sodium pyruvate-1-[ 13 C] this approach readily delivers 50-fold 13 C enhancements. 40 However, rapid in situ condensation of pyruvate with the amine carrier forms products of the type [IrIJH) 2 IJη 2 -αcarboxyimine)IJamine)IJNHC)] which deactivate the system to further pyruvate polarisation.…”

Benchtop NMR analysis of piperazine‐based drugs hyperpolarised by SABRE

“…Resultant SABRE-based experiments again yielded no hyperpolarisation. It is likely that in order to hyperpolarise this molecule, especially as it possesses a piperazine ring rather than an N-heterocycle, SABRErelay [6,7,21] may need to be employed in order to facilitate polarisation.…”

Rapid13C NMR hyperpolarization delivered frompara-hydrogen enables the low concentration detection and quantification of sugars

“…The isotopologue d 22 -5 further improved the signal enhancement to 257 AE 2 which is consistent with effects of deuteration reported elsewhere. 67,72 The corresponding 2 H labelled isotopomer of 6 was unable to be synthesised however we would expect a similar improvement in glucose polarization. In a second step, ve different NH carriers were tested with d 22 -5, ammonia (NH 3 ), benzylamine (BnNH 2 ), benzyl-d 7 -amine (d 7 -BnNH 2 ), phenethylamine (PEA) and phenethyl-1,1,2,2-d 4amine (d 4 -PEA).…”

“…Currently this mechanism has been shown to extend the range of molecules amenable to SABRE to include alcohols, amines, amides, carboxylic acids, phosphates, and carbonates. [64][65][66][67] In this work, we illustrate the rst in depth study of the hyperpolarization of 13 C NMR glucose and fructose via the SABRE-Relay method. We discuss the enhancement levels that can be obtained and demonstrate the viability of this simple method for tautomeric analysis and quantication of low mM concentrations of glucose.…”