Application of capillary-scale NMR for the structure determination of phytochemicals.
Employing a capillary-scale NMR probe enables the miniaturisation of structure determination and de-replication of purified natural products from plants using only 5-100 microg of material. Approximately 5 microg are required to perform one-dimensional proton and two-dimensional homonuclear (COSY and NOESY) NMR experiments; some 30 microg are needed to acquire HMQC- or HSQC-NMR spectra; ca. 75-100 microg are necessary to measure HMBC-NMR spectra; and around 200 microg of a compound are needed to perform 13C- and DEPT-NMR experiments. In order to illustrate the integration of the outputs from high-throughput natural product chemistry methods with the capabilities of the state-of-the-art CapNMR technology, the preparation of a natural product library from the extract of Penstemon centranthifolius, and the subsequent isolation, purification and structure determination of six known iridoid glycosides with 25-300 microg of material are presented.
Hu
Jin-Feng
JF
Lead Discovery and Rapid Structure Elucidation Group, Sequoia Sciences Inc., 11199 Sorrento Valley Road, Suite H, San Diego, CA 92121, USA. jhu@sequoiasciences.com
Garo
Eliane
E
Yoo
Hye-Dong
HD
Cremin
Peadar A
PA
Zeng
Lu
L
Goering
Matt G
MG
O'Neil-Johnson
Mark
M
Eldridge
Gary R
GR
D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification; D039823:Iridoids / Q000737:chemistry* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008904:Miniaturization / Q000379:methods*; D015394:Molecular Structure; D032263:Penstemon / Q000737:chemistry*
D006027:Glycosides; D039823:Iridoids