桂皮活性成分的微波萃取工艺与抗氧化作用

Microwave Extraction Process and Anti-oxidization of Active Components from Cinnamomi Cortex

摘要:

本文研究了桂皮活性成分的微波萃取工艺及抗氧化能力与活性成分的相关性。以DPPH自由基清除率和总还原能力（FRAP）为评价指标，以化学抗氧化剂二丁基羟基甲苯(BHT)、乙氧喹(EMQ)为阳性对照，在单因素试验的基础上通过正交试验优化桂皮的微波萃取工艺；建立提取物UPLC分离方法并建立UPLC-DPPH谱效关系阐述提取物抗氧化能力与活性成分的相关性。结果表明，以70%乙醇按10:1 mL/g液料比于65 ℃下微波萃取10 min，桂皮提取物的DPPH清除率高达92.18%、FRAP值32.90 μmol/L，其抗DPPH自由基能力（IC50 55.0 mg/L）是BHT（IC50 390 mg/L）的7倍与EMQ相当（IC50 55.0 mg/L）。对10批桂皮提取物的UPLC-DPPH谱效关系分析结果显示其抗DPPH自由基能力是桂皮醛、香豆素等多种活性成分共同作用的结果，而并非与桂皮醛的含量线性相关，说明仅仅以桂皮醛评价桂皮药材的质量是不全面的。

Abstract:

The microwave extraction process， the correlation of antioxidant abilities and active components from Cinnamomi cortex were investigated in this study. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging rate and ferric reducing antioxidant power (FRAP) were used as the evaluation indexes. The chemical antioxidants butylated hydroxytoluene (BHT) and ethoxyquine (EMQ) were used as positive control. Based on the single-factor tests, the microwave extraction process of active components from Cinnamon cortex was optimized by orthogonal experimental design. The ultra performance liquid chromatography (UPLC) separation method was established for active components extracted from Cinnamomi cortex and the correlation of antioxidant capacity of the extract and active components was elucidated by UPLC-DPPH coupled method. The results showed that the optimized extraction process of Cinnamomi cortex was as follows: ethanol 70%, ratio of liquid-solid was 10:1 (mL/g), extracting temperature 65℃ and extraction time 10 min. And the extracts obtained from Cinnamomi cortex showed much higher DPPH radical scavenging rate of 92.18% and FRAP value of 32.90 μmol/L. The IC50 of Cinnamomi cortex extract on DPPH radical scavenging rate was 55.0 mg/L, which was almost equal to seven times of that of BHT (IC50=390 mg/L) and equivalent to that of EMQ (IC50=55.0 mg/L). Analysis of DPPH radical scavenging rates and UPLC chromatograms of 10 batches of Cinnamomi cortex extracts showed that the anti-DPPH free radicals were due to the interaction of various active components such as cinnamaldehyde and coumarin, but not linearly related to the content of cinnamaldehyde. It was not comprehensive to evaluate the quality of Cinnamomi cortex only with cinnaldehydum.