From Retrospective Assessment to Prospective Decisions in Natural Product Isolation: HPLC-SPE-NMR Analysis of Carthamus oxyacantha

Abstract

An extract of Carthamus oxyacantha (wild safflower) was investigated using two approaches: a traditional, nontarget fractionation by VLC and HPLC, and the hyphenated technique HPLC-PDA-HRMS-SPE-NMR followed by targeted isolation of selected constituents for inclusion in a screening library of pure natural products. While the nontarget fractionation involved considerable time spent on pursuing fractions containing well-known or undesired compounds, the hyphenated analysis was considerably faster and required less solvent and other consumables. The results were used to design and execute an optimized, HPLC-HRMS-guided, targeted isolation scheme aiming exclusively at a series of identified spiro compounds. Thus, HPLC-PDA-HRMS-SPE-NMR is a dereplication technique of choice, allowing economical acquisition of comprehensive data about compounds in crude extracts, which can be used for rational, prospective decisions about further isolation efforts. A total of 15 compounds were identified in the extract. Six spiro compounds, of which four have not previously been characterized, and tracheloside (a lignin glucoside) are presented with assigned 1H and 13C chemical shifts.

Cholinesterase inhibitors isolated from bilberry fruit

“…In contrast, it could also be the wellknown 4-(β-D-glucopyranosyloxy)-3-methoxybenzoic acid (Fig. 2g), previously isolated from Carthamus oxyacantha (Johansen, Wubshet, Nyberg, & Jaroszewski, 2011). It is important to note that ion 353 Da was also eluted at 7.5 min.…”

Characterization of Antileishmanial Compounds from Lawsonia inermis L. Leaves Using Semi-High Resolution Antileishmanial Profiling Combined with HPLC-HRMS-SPE-NMR

“…While the commonly used hyphenation of high-performance liquid chromatography coupled with high-resolution mass spectrometry (HPLC-HRMS) is a fast and sensitive technique, it has several limitations when it comes to full structural elucidation of complex natural products. Especially promising is therefore the additional hyphenation of HPLC and HPLC-HRMS with solid-phase extraction and nuclear magnetic resonance spectroscopy, i.e., HPLC-(HRMS)-SPE-NMR (Lambert et al, 2005; Johansen et al, 2011), which allows full structural identification of complex natural products directly from crude extracts. As HPLC-HRMS-SPE-NMR only allows for chemical analysis, the recent combination with semi-high-resolution and/or high-resolution bioactivity profiling, i.e., microfractionation in microplates followed by bioassaying to yield a semi-high or high-resolution inhibition profile, is one of the most promising technological developments within bioanalytical plant research.…”

Molecular Networking as a Dereplication Strategy

“…3 Current dereplication strategies include hyphenated techniques, such as HPLC-MS, HPLC-NMR, HPLC-NMR-MS, and HPLC-SPE-NMR, 4-6 or bioactivity fingerprints, such as cytological profiling or BioMAP. 7,8 The common denominator of these strategies is the attempt to exploit the fact that structurally similar or identical molecules share similar physical characteristics, such as UV-vis profiles, chromatographic retention times, MS, NMR chemical shifts, or biological properties.…”