Microwave-Assisted Extraction of Ricinine from <i>Ricinus communis</i> Leaves

• Main Authors: Liliane Nebo, Rosa M. Varela, João B. Fernandes, Miguel Palma
• Format: Article
• Language: English
• Published: MDPI AG 2019-10-01
• Series: Antioxidants
• Subjects: microwave assisted-extraction; ricinine; <i>ricinus communis</i>; uplc; response surface methodology
• Online Access: https://www.mdpi.com/2076-3921/8/10/438

The alkaloid ricinine (3-cyano-4-methoxy-N-methyl-2-pyridone) is found in different parts of the <i>Ricinus communis</i> plant and is known to possess several bioactive properties, including strong antioxidant activity. In this study, a new microwave-assisted extraction (MAE) method was developed for the recovery of ricinine from <i>R. communis</i> leaves. The extraction variables studied were extraction temperature (between 125 &#176;C and 175 &#176;C), microwave power (between 500 W and 1000 W), extraction time (between 5 min and 15 min), extraction solvent (between 10% and 90% of EtOAc in MeOH), and solvent-to-sample ratio (between 25:1 mL and 50:1 mL of solvent per gram of the sample). On studying the effects of extraction variables, both solvent and liquid-to-solid ratio were found to exhibit the highest effects on ricinine recovery. A fast (15 min) microwave-assisted extraction method was developed (high temperatures can be applied because the stability of ricinine is proven in the literature), allowing for the recovery of ricinine from <i>R. communis</i> leaves. The study revealed that <i>R. communis</i> leaves had almost 1.5 mg g^&#8722;1 (dried weight) of ricinine.