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Centrifugal partition chromatography (CPC) and all countercurrent separation apparatus provide chemists with efficient ways to work with complex matrixes, especially in the domain of natural products. However, despite the great advances provided by these techniques, more efficient ways of analyzing the output flow would bring further enhancement. This study describe a hyphenated approach made by coupling NMR with CPC through a hybrid-indirect coupling made possible by using a solid phase extraction (SPE) apparatus intended for high-pressure liquid chromatography (HPLC)-NMR hyphenation.

Dimeric stilbene glucosides 1–3 [two diastereomers of (−)-gnemonoside A (1a and 1b), (−)-gnemonoside C (2), and (−)-gnemonoside D (3)] as well as a mixture of the two enantiomers of gnetin C (4) were isolated from the rhizomes of Gnetum africanum. The two enantiomers of gnetin C, (+)-4 and (−)-4, were obtained from the aglycones of 1a and 1b, respectively. The configurations of these stilbenoids were investigated by NMR and vibrational circular dichroism (VCD) experiments.

Countercurrent chromatography techniques are increasingly used in the fractionation and purification steps of natural products due to their excellent versatility and efficiency. However, one of the major bottlenecks in liquid-liquid chromatography is the solvent system selection. In this work, a NMR-based analysis of complex solvent mixtures was developed for biphasic system selection and modification. This allowed us to develop more versatile separation conditions, such as gradients. Additionally, we hyphenated our countercurrent chromatography device with NMR and mass spectrometry.