摘要
RA-MMIPs were synthesized using a multi-monomer strategy. • RA-MMIPs showed fast adsorption, high absorption amount, good selectivity to RA and reusability. • RA-MMIPs could efficiently isolated rosmarinic acid and its analogues from Orthosiphon aristatus . • The isolates exhibited enhanced antioxidant activity than the original extract. In this study, rosmarinic acid-magnetic molecularly imprinted nanoparticles (RA-MMIPs) were synthesized using a multi-monomer strategy and characterized through nine methods. Adsorption/desorption evaluation showed a series of advanced properties, like fast adsorption equilibrium (120 min), high adsorption amount (311.38 mg/g), and good reusability (>7 cycles) compared with previously reported adsorbents. These was from the multi-interactions with rosmarinic acid, such as borate ester covalent bond, hydrogen bond, cation-π interaction, etc. RA-MMIPs showed favorable selectivity for rosmarinic acid over its analogues, including gallic acid, chlorogenic acid, caffeic acid, and ferulic acid with selectivity coefficients of 3.10, 6.82, 3.88 and 3.69, respectively. Finally, RA-MMIPs were successfully used to selectively separate rosmarinic acid and its analogues with 98.04% adsorption rate from Orthosiphon aristatus extract. Antioxidant assays of purified rosmarinic acid and its analogues revealed that the IC 50 values for DPPH and ABTS radical scavenging decreased to 12.563 ± 0.561 μg/mL and 24.403 ± 2.602 μg/mL, which were significantly lower than those of the original extract (69.208 ± 2.380 μg/mL and 94.772 ± 0.272 μg/mL). The FRAP absorbance at 700 nm increased from 0.117 ± 0.001 to 0.365 ± 0.003, further confirming the enhanced antioxidant activity. The efficient molecularly imprinted adsorbent of RA-MMIPs provided a novel approach for selectively acquiring highly potent antioxidant compounds from complex natural products. Download: Download high-res image (271KB) Download: Download full-size image
危险品化学品经营许可证（带存储）