A rapid optimization method for Sepbox system separation using HPTLC: an application of Cerbera manghas L. separation†

The rapid isolation of natural products and efficient drug screening are pivotal in expediting drug development. Techniques ranging from traditional open column chromatography to medium-pressure liquid chromatography (MPLC), and the latest Sepbox technology, have been developed to accelerate separation processes and streamline drug development timelines. The Sepbox system combines two-dimensional high-performance liquid chromatography (2D-HPLC) and solid-phase extraction (SPE) technologies, coupled with UV and evaporative light scattering detection (ELSD) systems, offering various column options to cater to diverse sample requirements. Furthermore, the Sepbox system automates and expedites sample fractionation into numerous fractions, facilitating subsequent high-throughput screening and analysis. Despite previous emphasis on 2D-HPLC development, optimizing separation conditions with the Sepbox system poses challenges due to the requirement for substantial sample and solvent quantities, limiting its practicality compared to conventional methods. Hence, this study employed eight standard compounds to explore the correlation between retention factor (R_f) values obtained from high-performance thin-layer chromatography (HPTLC) plates and retention times on the Sepbox main column. Mass spectrometry was utilized to confirm the retention times of the standard compounds. The findings yielded a conversion equation between HPTLC R_f values and Sepbox main column retention times, thereby enhancing the separation efficiency of Sepbox 2D-2000 system. Finally, the efficacy of this method was validated using Cerbera manghas leaf crude extracts and its purified compounds, demonstrating the rapid optimization of suitable elution conditions for the Sepbox 2D-2000 system using HPTLC.