脱油油樟叶总酚提取纯化工艺优化及体外抗氧化研究

Optimization of Extraction and Purification Process of Total Phenols from Deoiled Cinnamomum longepaniculatum camphor Leaves and its Antioxidant Study in Vitro

关键词:  油樟叶  总酚  提取  纯化  大孔树脂  抗氧化

Key words:  Cinnamomum longepaniculatum  total phenols  extract  purification  macroporous resin  antioxidant

摘要:

摘要：目的 优选脱油油樟叶总酚的提取纯化工艺，考察纯化前后的抗氧化活性，为油樟合理开发和利用提供依据。方法 在单因素实验基础上结合正交试验法，优选提取工艺;采用大孔吸附树脂法，优选纯化工艺;并采用DPPH、ABTS+法及总还原能力测定比较总酚纯化前后的体外抗氧化活性。结果 总酚最佳提取工艺：液料比30 mL·g-1，乙醇浓度50%，回流时间120min，温度90℃，次数2次，脱油油樟叶总酚提取量为15.63 mg·g-1。最佳纯化工艺：采用HPD-600树脂，上样液浓度0.5g·L-1，上样液pH3.0，上样量2.5BV，上样流速1mL·min-1，6BV蒸馏水除杂，乙醇洗脱浓度为60%,洗脱液pH7.0，洗脱流速1 mL·min-1，收集4BV洗脱液，总酚含量由12.51%提升至26.40%。纯化后总酚体外抗氧化能力良好，DPPH、ABTS+自由基清除能力IC50值分别为(38.07±0.66) mg·L-1、(14.28±0.19) mg·L-1，总还原能力为纯化前的1.68倍。结论 该工艺方法稳定可行，适合工业生产，具有简便、快速、准确等优点，为油樟的进一步研究及开发奠定基础。

Abstract:

ABSTRACT: OBJECTIVE To explore the optimal process of extraction and purification of total phenols from deoiled Cinnamomum longepaniculatum camphor leaves, and to evaluate the antioxidant activity in vitro before and after purification, so as to provide the theoretical basis for rational development and utilization of Cinnamomum longepaniculatum camphor. METHODS The L18(37)orthogonal experiment was carried out on the basis of five-single factor and three-level experiments, such as concentration of ethanol(A), ratio of liquid-material(B), extraction temperature(C), extraction time(D), and extraction times(E). The extraction process of total phenols was optimized, by taking the amount of total phenols extraction as the process investigation index. Taking the adsorption and desorption performance under dynamic and static conditions as the investigation index of the total phenols purification process, the purification process of total phenols was optimized by macroporous resin. With vitamin C as positive control, the antioxidant activity in vitro of total phenols before and after purification was evaluated by DPPH radical scavenging, ABTS+ radical scavenging, and determination of total reducing capacity. RESULTS The best extraction technology conditions of total phenols were as follows: ratio of liquid-material 30mL?g-1, concentration of ethanol 50%, extraction time 120min, extraction temperature 90℃, extraction 2 times. Under such conditions, the extraction amount of total phenols from deoiled Cinnamomum longepaniculatum camphor leaves was 15.63 mg·g-1. HPD-600 type macroporous resin showed the best purifying profile. The best purification technology conditions were as follows: the concentration of sample solution was 0.5 g?L-1, the sample solution pH value was3.0, the sample volume was2.5BV, the sample flow rate was1 mL·min-1, the impurity was removed by 6BV distilled water, the elution concentration of ethanol was 60%, the eluate pH value 7.0, the elution flow rate 1 mL·min-1, 4BV eluent was collected and the total phenols assay was increased from 12.51% to 26.40%. The purified total phenols showed excellent antioxidant activity in vitro. The scavenging effect of total phenols after purification on DPPH and ABTS+free radicals increased with the increase of total phenols concentration. The IC50 values of DPPH radical scavenging activity of total phenols before and after purification were (68.31 ±1.96) mg·L-1 and (38.07 ±0.66) mg·L-1, respectively. The IC50 values of ABTS+ radical scavenging activity of total phenols before and after purification were (23.88 ±1.66) mg·L-1and (14.28 ±0.19) mg·L-1, respectively. The absorbance values of the total reducing capacity of total phenols before and after purification were (1.57 ±0.01) and (2.64 ±0.02), respectively, which was 1.68 times higher than that before purification. The scavenging effect of total phenols before and after purification on DPPH, ABTS+ free radical scavenging, and total reducing capacity were weaker than that of Vc. CONCLUSION The process is stable and feasible, suitable for industrial production, and has the advantages of simplicity, rapidity, and accuracy, which lays a foundation for further research on Cinnamomum longepaniculatum camphor and the development of natural antioxidants.