Variations in Essential Oil Yield, Composition, and Antioxidant Activity of Different Plant Organs from Blumea balsamifera (L.) DC. at Different Growth Times

Blumea balsamifera, also named Ainaxiang, is widely used as an ancient medicinal herb in tropical and subtropical Asia. It is rich in essential oils. In this work the essential oils of B. balsamifera from different plant organs and in different months were extracted, and then analyzed by gas chromatography-mass spectrometry. The results showed that essential oil yield of young leaves was the highest (0.65 mL/100 g), followed by mature leaves (0.57 mL/100 g), and the oil yield was higher in October (0.47 mL/100 g) than other months. A total of 44 compounds were identified, representing 92.64%-96.71% of the oil. Eighteen common chemical components were found among the six plant organs, representing >80% of the oil constituents. l-borneol was the main ingredient in leaves, and its content was the highest in senescent leaves and in December. In the essential oils of young shoots and young stems, the main component was dimethoxydurene. Antioxidant activity was also determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and beta-carotene bleaching (BCB) assays. The results indicated that the beta-carotene bleaching activity was far stronger than the DPPH radical-scavenging capacity, and the young leaves and young shoots showed stronger antioxidant activity. Dimethoxydurene, beta-caryophyllene, and beta-caryophyllene play a positive role in good antioxidant activity, while beta-eudesmol, phytol, and tetradecanal play a negative role. The antioxidant activity revealed in this study might help in developing this promising bioresource for use in the medicinal and cosmetic industries.