不同采摘月份木姜子果挥发性成分测定

Determination of Volatile Components of Litsea euosma Fruit in Different Harvest Months

【目的】测定不同采摘时期的木姜子果挥发性化学成分。【方法】以5、6和7月蒙自清香木姜子果为材料,采用油浸提(热浸提和冷浸提)、超声波辅助浸提和水蒸气蒸馏法3种方法提取木姜子果精油;采用顶空进样法加热提取木姜子挥发性成分,并对其进行气相色谱—质谱(GC-MS)分析;结合计算机检索技术对其化学成分进行分离和鉴定,应用色谱峰面积归一化法测定各组分的相对百分含量。【结果】筛选出制备木姜子精油的最佳工艺为:水蒸气蒸馏法,时间3 h,料液比1∶4(g∶mL)。采用该方法从5、6和7月木姜子果中分别分离和鉴定出化合物32、49和98种,分别占检出总量的78.36%、87.49%和98.04%。其中,5月果萜烯类和醇类成分和含量较多,分别占总百分含量的45.97%和26.14%;6月果萜烯类和醛类成分和含量较多,分别占总量的33.29%和34.39%;7月果主要挥发性成分是醛类,占总量的53.74%。【结论】5、6和7月木姜子果提取的精油所含挥发性化学成分和含量不同。5月果主要挥发性化学成分是萜烯类;6月果主要挥发性成分是萜烯类及醛类;7月果主要挥发性成分是醛类,且倍半萜类化合物含量增加。

[Purpose]The volatile components in Litsea euosma were determined at different picking periods.[Method]The essential oil was extracted from the fruits of L.euosma harvested in May,June and July by three methods,such as oil extraction(heat extraction and cold extraction),ultrasonic assisted extraction and steam distillation.The volatile components were extracted by headspace sampling.And its chemical components were separated and identified by the gas chromatography-mass spectrometry(GC-MS)combined with searches technology of computer.The relative contents in the volatile oil were determined by area normalization method.[Result]The optimal method for preparing the essential oil was as follows:steam distillation,time 3 h,and the solid-liquid ratio was 1∶4(g∶mL).Using the method of steam distillation,totally 32,49 and 98 volatile components were identified in the oil derived from three peaking periods,respectively,accounting for 78.36%,87.49%and 98.04%of the total detection.In May,there were more terpenes and alcohols that accounting for 45.97%and 26.14%of the total content.In June,fruit terpenes and aldehydes had more components and contents,accounting for 33.29%and 34.39%of the total content.The main volatile component of July fruit is aldehydes,accounting for 53.74%of the total percentage.[Conclusion]It was found the volatile chemical constituents and contents of the essential oil extracted from L.euosma were different in three picking periods.In May,the volatile chemical constituents were terpenes,while in June,were terpenes and aldehydes.In July,the volatile chemical constituents were aldehydes and the content of sesquiterpenes increased.