Targeted enrichment of bruceine D from Brucea javanica by molecularly imprinted nanomagnetic sorbents

Abstract

This study aimed to develop and validate a novel method for targeted enrichment of bruceine compounds, whose structural complexity hinders both synthesis and conventional natural extraction. As a case study, bruceine D, a major antitumor component from Brucea javanica (Yadanzi in Chinese), was selected for enrichment using magnetic nanoparticles (MNPs) functionalized with molecularly imprinted polymers (MIPs). A comprehensive chemical profiling of the B. javanica extract was performed to identify bruceine D and its structural analogues. MNPs coated with bruceine D-MIPs (MMIPs) were synthesized and characterized using various techniques, including transmission electron microscopy to observe the morphology, scanning electron microscopy to analyze the surface structure, and Fourier-transform infrared spectroscopy to confirm the successful functionalization of MIPs on MNPs. The adsorption performance of MMIPs was assessed through static and dynamic adsorption experiments . Subsequently, the process was validated for selectivity, repeatability, and reusability. The adsorption data were modeled using the Freundlich isotherm and kinetic models to reveal the adsorption mechanism. Among multiple analogues, bruceine D was confirmed as a major constituent of the B. javanica extract. The MMIPs demonstrated superior morphology, crystallinity, and functional surface modification, leading to favorable adsorption characteristics. Compared to non-imprinted polymers, they exhibited significantly stronger adsorption intensity and selectivity for bruceine D due to a lower Freundlich isotherm constant (0.041 8) and a higher imprinting factor (1.69). The MMIPs showed excellent repeatability with a low relative standard deviation (0.75%) and maintained high extraction efficacy across multiple cycles. The MMIPs successfully isolated bruceine D from B. javanica extract, achieving a remarkable recovery yield (39.50 µg/g). This study demonstrated a novel application of molecular imprinting technology targeting bruceine compounds. In particular, the MMIP-based selective enrichment of bruceine D from B. javanica showed superior efficiency, selectivity, and adsorption capacity compared to conventional methods. This advancement holds significant implications for natural product isolation, offering a sustainable and green strategy in the pharmaceutical industry for the isolation of complex bioactive compounds for therapeutic use.