Efficient Preparation of High-Purity Sulforaphene: Selective Immobilization of Myrosinase by Designing a Concanavalin A-Loaded Metal–Organic Framework

Isothiocyanates (ITCs) in cruciferous plants are natural active ingredients with cancer-preventive, anti-inflammatory, and antibacterial functions. ITCs are generated through the hydrolysis of glucosinolates by myrosinase (MYR). However, the presence of specifier proteins, especially epithionitrile-specifier proteins (ESPs), significantly impacts the yield, purification, and application of ITCs. Herein, we designed a metal–organic framework to selectively immobilize MYR by constructing a concanavalin A (ConA)-loaded ZIF-8 core. The 1.55-fold higher sulforaphane (SFE)-generation activity of ConA-MYR@ZIF-8 compared to ConA-free groups demonstrated the selectivity of ConA@ZIF-8 toward MYR. Impurities, including nitrile generated by ESP, were effectively excluded. ConA-MYR@ZIF-8 maintained over 93.9% activity after 1 week of storage at 4 °C and retained 77.9% activity after 20 cycles. SFE with 97.8% purity was prepared in a yield of 14.9 mg/(g·h) through enzymatic reactions coupled with real-time dichloromethane column extraction, achieving a recovery rate of 90.1%. This study provided new insights for the efficient preparation of SFE and other ITCs.