Advances in applications of metal-organic frameworks for selective separation of target substances from natural sources

Natural compounds exhibit diverse biological activities and play a pivotal role in pharmaceutical, functional food, and cosmetic industries. Their extraction frequently suffers from low efficiency and depends on toxic reagents, hence, greener separation approaches are highly desirable. Metal-organic frameworks (MOFs) have emerged as promising porous materials to address these issues, offering distinct advantages in the selective capture of target molecules and the mitigation of matrix interference. This review critically evaluates the applications of MOFs and MOF-based composites, including those incorporating molecularly imprinted polymers (MIPs) and graphene, in the separation of nine classes of bioactive compounds and toxic ingredients from natural sources. Special emphasis is placed on the structure-function relationships governed by metal nodes, organic linkers, and their coordination environments, which collectively dictate binding affinity and selectivity. These insights provide a roadmap for the rational design of MOFs tailored to specific target analytes. The review concludes with a forward-looking perspective on future research directions and potential technological advancements in this rapidly evolving field.