An automated preparative liquid chromatography platform for repetitive purification of coumarins from Cortex Fraxini...

Purification in the industry often requires repeated purification of large volume sample using a fixed chromatographic process. Therefore, this study aimed to design an automated chromatographic system which is able to process virtually unlimited sample volume using the minimalism principle. An automated repetitive purification liquid chromatography (ARP-LC) system was developed using active-pump-based sampling and cyclic operational control. The system demonstrated exceptional precision, with injection reproducibility yielding RSD ≤ 1.32% in peak area and retention time stability of ≤ 0.69% RSD. When applied to the purification of coumarins from Cortex Fraxini extract, the system efficiently processed 4 L of the sample, yielding 11 distinct fractions in only seven consecutive runs. Subsequent activity-guided purification identified several high-purity coumarin compounds exhibiting significant antioxidant (EC₅₀ values as low as 5 μg/mL) and antibacterial activities. The ARP-LC system showcases high robustness, scalability, and compatibility with medium- to high-pressure chromatographic modes, providing an efficient and reproducible platform for the large-scale purification of complex natural products with clear implications for pharmaceutical development and industrial applications.