Coupling countercurrent chromatography to mass spectrometry to resolve natural products complex mixtures.

Countercurrent chromatography coupled with mass spectrometry (CCC-MS) has become a powerful tool for analysing complex natural product mixtures. This method provides high resolution, minimal sample loss, and versatility for both preparative and analytical applications. CCC, a liquid-liquid chromatography technique, excels in managing the inherent complexity of metabolomes, while MS offers sensitive detection and structural elucidation. The evolution of CCC-MS has faced early challenges, particularly regarding interfacing and ionisation efficiency. However, its development has propelled advancements such as reduced-pressure ionisation methods (e.g., ESI, APCI) and offline hyphenation strategies. Recent applications have demonstrated its effectiveness in metabolite profiling, isolating target compounds, and bio-guided fractionation, which contribute to the discovery of novel metabolites and their biological activities. Despite ongoing challenges in data analysis, improvements in data processing tools and molecular networking platforms are enhancing compound annotation and discovery. Overall, CCC-MS continues to be a critical asset in natural product research, providing valuable insights into the structural diversity of bioactive compounds.