Investigation of adsorption behavior and scale up for hydroxysafflor yellow A purification from Safflower: a case study

Given the complexity of natural extracts, multiple purification steps are often required to satisfy strict purity requirements for the isolated product. In this context, mathematical modeling could be a useful tool to evaluate the feasibility of large-scale purification and to find optimal elution conditions without relying on the traditional trial-and-error method. In this work, the thermodynamic behavior of Hydroxysafflor yellow A (HSYA), the primary bioactive pigment in the safflower plant, has been modeled and simulated under gradient elution conditions in analytical scale to find optimal parameters for its isolation under preparative scale. Adsorption isotherm parameters were determined through the so-called inverse method in the analytical scale and further confirmed in the preparative scale. The general rate model accurately predicted elution profiles by considering all mass transfer resistances between the stationary and mobile phases, with excellent agreement between simulated and experimental data. It resulted that the optimization of process operating variables led to an increase of the HSYA purity from 20% (crude extract) to 80% (after enrichment), and further purified to 95% using reversed-phase preparative chromatography. The proposed workflow offers a scalable and sustainable strategy for purifying a natural compound using enrichment and subsequent purification techniques.