title: Application of capillary-scale NMR for the structure determination of phytochemicals.
abstract: 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.
authors.affiliation: Lead Discovery and Rapid Structure Elucidation Group, Sequoia Sciences Inc., 11199 Sorrento Valley Road, Suite H, San Diego, CA 92121, USA. jhu@sequoiasciences.com
authors.forename: Jin-Feng
authors.initials: JF
authors.lastname: Hu
authors.forename: Eliane
authors.initials: E
authors.lastname: Garo
authors.forename: Hye-Dong
authors.initials: HD
authors.lastname: Yoo
authors.forename: Peadar A
authors.initials: PA
authors.lastname: Cremin
authors.forename: Lu
authors.initials: L
authors.lastname: Zeng
authors.forename: Matt G
authors.initials: MG
authors.lastname: Goering
authors.forename: Mark
authors.initials: M
authors.lastname: O'Neil-Johnson
authors.forename: Gary R
authors.initials: GR
authors.lastname: Eldridge
mesh_terms: 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*
chemical_list: D006027:Glycosides; D039823:Iridoids