Low-level long-range H-1-N-15 heteronuclear shift correlation at natural abundance using a combination of 2D and selective 1D NMR methods with submicro NMR probe technology

There has been burgeoning interest in the utilization of N-15 as a structur al probe. A growing body of reports have appeared using gradient long-range H-1-N-15 heteronuclear shift correlation experiments at natural abundance. The majority of studies have reported data acquired using conventional 5 m m NMR probe technology, which has mandated the use of sizable samples to ma intain appropriate working concentrations to keep data acquisition times ma nageable. This paper reports the combined utilization of gradient 2D and se lective 1D H-1-N-15 GHMBC NMR methods in conjunction with SMIDG (submicro i nverse-detection gradient) NMR probe technology at 600 MHz which allows the acquisition of high quality, long-range natural abundance H-1-N-15 heteron uclear shift correlation data on samples as small as 1 mu mol in 22h and 0. 5 mu mol over a long weekend (84h). In contrast, using 2D NMR methods alone , data on a 1 1 mu mol sample of strychnine acquired over a weekend (65h) a re still of marginal quality. Copyright (C) 1999 John Wiley & Sons, Ltd.