Publications [#328158] of Warren S. Warren

Journal Articles
  1. Colell, JFP; Emondts, M; Logan, AWJ; Shen, K; Bae, J; Shchepin, RV; Ortiz, GX; Spannring, P; Wang, Q; Malcolmson, SJ; Chekmenev, EY; Feiters, MC; Rutjes, FPJT; Bl├╝mich, B; Theis, T; Warren, WS, Direct Hyperpolarization of Nitrogen-15 in Aqueous Media with Parahydrogen in Reversible Exchange., Journal of the American Chemical Society, vol. 139 no. 23 (June, 2017), pp. 7761-7767 [doi] .

    Signal amplification by reversible exchange (SABRE) is an inexpensive, fast, and even continuous hyperpolarization technique that uses para-hydrogen as hyperpolarization source. However, current SABRE faces a number of stumbling blocks for translation to biochemical and clinical settings. Difficulties include inefficient polarization in water, relatively short-lived 1H-polarization, and relatively limited substrate scope. Here we use a water-soluble polarization transfer catalyst to hyperpolarize nitrogen-15 in a variety of molecules with SABRE-SHEATH (SABRE in shield enables alignment transfer to heteronuclei). This strategy works in pure H2O or D2O solutions, on substrates that could not be hyperpolarized in traditional 1H-SABRE experiments, and we record 15N T1 relaxation times of up to 2 min.