蝉虫草样品的分级萃取与化学成分分析

利用索氏萃取技术,依次采用石油醚、乙酸乙酯、丙酮、无水乙醇和甲醇等5种溶剂对蝉虫草纯粉进行分级萃取,运用傅里叶变换红外光谱分析法和气相色谱-质谱联用技术对5级萃取物进行分析鉴定。傅里叶变换红外光谱分析显示萃取物中含有与烯烃类、羧酸类、酯类、醇类和酮类等化合物相关的C-H、C=O、C-O和C=C等官能团。气相色谱-质谱联用技术共鉴定出有机小分子化合物34种,以酯类和脂肪酸类为主,多为碳链长度为15-20的长链脂肪酸及对应的酯,其中十八碳不饱和脂肪酸相对含量高达28.95%;分别存在于两种或以上萃取物中的有机化合物共有11种;仅存于石油醚萃取物中的化合物6种,乙酸乙酯萃取物中3种,丙酮萃取物中2种,无水乙醇萃取物中6种,甲醇萃取物中6种。在一定极性范围内,利用溶剂的极性梯度变化,可实现蝉虫草中活性物质的按极性梯度分离;采用分级萃取技术可有效分离蝉虫草中部分化学成分。鉴定结果充实了蝉虫草中化合物的种类资源,为蝉虫草中活性物质谱图库的完善、构效关系的建立及蝉虫草产品的利用开发提供支撑。

Fractional extraction and identification of the chemical components from Cordyceps cicadae product

Pure powder of Cordyceps cicadae was extracted with petroleum ether, ethyl acetate, acetone, absolute ethanol and methanol by use of Soxhlet extraction method. Five extractable portions (E₁, E₂, E₃, E₄ and E₅) were obtained and analyzed by Fourier transform infrared spectrometry (FTIR) and gas chromatography-mass spectrometry (GC/MS). The functional groups such as C-H, C=O, C-O and C=C were observed in FTIR spectra of five extract portions. In total, 34 compounds were identified for E₁-E₅ by using GC/MS. These compounds were dominated by fatty acids and their corresponding esters, especially long-chain fatty acid and their corresponding esters with carbon atoms of 15-20. The content of unsaturated fatty acid with C18 was up to 28.95%. Eleven compounds were detected in two or more extract portions. Six compounds were detected in E₁, 3 compounds in E₂, 2 compounds in E₃, 6 compounds in E₄ and 6 compounds in E₅. Within a certain polarity range, the active substances of Cordyceps cicadae can be extracted according to the polarity gradient of solvents. The chemical components can be effectively separated by fractional extraction. The results provide theoretical support for the establishment of the spectral library of active substances and relationship between chemical structure and medicinal efficacy of Cordyceps cicadae products and comprehensive utilization and development of Cordyceps cicadae production.