Extraction Process Optimization, Composition Analysis of Essential Oil from Chimonanthus nitens Oliv and Its Antioxidant Activity

Objective: The present study aimed to optimize the extraction process and evaluate the constituents, antioxidant properties of essential oil from Chimonanthus nitens Oliv. Methods: The microwave-assisted steam distillation extraction of essential oil from Chimonanthus nitens Oliv was optimized by orthogonal design, and the extraction rate of the essential oil from Chimonanthus nitens Oliv was employed as the index to evaluate the optimum process. Subsequently, gas chromatography-mass spectrometry (GC-MS) was applied to determine the chemical components of the essential oil of Chimonanthus nitens Oliv. In addition, the antioxidant activity of the essential oil was evaluated by taking 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical, reducing power and chelating ability of metal ions as indicators. Results: The optimal extraction extraction conditions were microwave time 10 min, ratio of material to liquid 1:25 g/mL, steam distillation time 5 h. In this contions, the extraction rate of the essential oil from Chimonanthus nitens Oliv was 1.7792%. Furthermore, a total of 21 chemical compounds were identified in the essential oil of Chimonanthus nitens Oliv, which contained lipids and terpenoid, among them, (1-methyl-4-propyl-1-ene-2-cyclohexyl) acetate was 50.67%, followed by α-pinene (6.92%), α-terpinyl acetate (5.77%), humulene epoxide II (3.96%), pseudolimonen (3.21%) and germacrene D (3.12%). Moreover, antioxidant activity analysis indicated that the essential oil from Chimonanthus nitens Oliv possessed certain antioxidant activity. Briefly, the IC₅₀ of the essential oil ivolved in the DPPH free radical scavenging assay, was 81.6 mg/mL. Furthermore, the reduction force of the essential oil could be achieved to the level of the positive control group, when its concentration was 10 mg/mL, and the half inhibition concentration of the chelating ability of metal ions was 17.16 mg/mL. Conclusion: In this paper, the microwave-assisted steam distillation extraction of essential oil from Chimonanthus nitens Oliv was optimized, the chemical components of the essential oil of Chimonanthus nitens Oliv was analyzed by GC-MS, and its antioxidant activity was demonstrated in this work.