不同超声辅助提取桂花黄酮及其抑菌性

Different ultrasound-assisted extraction processes of Osmanthus fragrans flavonoids and its antifungi activitiy

摘要:

为了探究桂花黄酮的最佳提取工艺及其对白色念珠菌的抑菌效果进行了以下实验：对超声提取法、超声辅助酶提取法和超声辅助双水相提取法提取桂花黄酮的提取率进行比较，选择提取率最高的方法，进行了单因素和响应面的工艺优化实验；采用超高效液相色谱-串联质谱（UPLC-MS/MS）对四个品种的桂花黄酮化合物进行了单体成分的鉴定；并测定了四个品种桂花黄酮对白色念珠菌的最小抑菌浓度（MIC）及其对菌体细胞膜完整性和生物膜形成的影响。结果表明，经超声提取桂花黄酮的提取率最高，经单因素和响应面实验优化后，其最佳提取条件为温度50 ℃，液固比17 mL/g，乙醇浓度52%，在此条件下，金桂、银桂、丹桂、四季桂的提取率分别为13.88%、8.79%、13.16%和10.28%；四种桂花黄酮对白色念珠菌的抑菌效果不同。其中，金桂的效果最好，MIC值为1.5 mg/mL，能够显著提高白色念珠菌细胞膜的通透性，导致细胞内容物流出，抑制生物膜的形成，抑制率最高可达46.59%。

Abstract:

In order to investigate the optimal extraction process of Osmanthus fragrans flavonoids and their antifungal effect on Candida albicans (C. albicans), the following experiments were conducted. The extraction rates of Osmanthus fragrans flavonoids by ultrasonic extraction, ultrasonic-assisted enzyme extraction and ultrasonic-assisted double aqueous phase extraction were compared, the method with the highest extraction rate was selected for process optimization experiments of single factor and response surface; the components of four varieties of Osmanthus fragrans flavonoids were identified by liquid chromatography-mass spectrometry (UPLC-MS/MS). The inhibition effects of four varieties of Osmanthus fragrans flavonoids on C. albicans in terms of minimum inhibitory concentration (MIC), cell membrane integrity and biofilm formation were determined. The results showed that after the single-factor and response surface optimization experiments, the best extraction process of cinnamon flavonoids was 50 ℃, the liquid-solid ratio was 17 mL/g, and the ethanol concentration was 52%, and the best extraction rate were 13.88% for Thunbergii group, 8.79% for Latifolius group, 13.16% for Aurantiacus group, and 10.28% for Semperflorens group under these conditions. Under these conditions, the extraction rates of thunbergii group, latifolius group, aurantiacus group and semperflorens group were 13.88%, 8.79%, 13.16% and 10.28%, respectively. The antifungal effect of different varieties of Osmanthus fragrans flavonoids on C. albicans was different, among which, Osmanthus fragrans var. thunbergii had the best antifungal effect with MIC value of 1.5 mg/mL, which could significantly improve the permeability of the cell membrane of C. albicans within 24 h, leading to the efflux of cell contents, and the inhibition rate of biofilm formation could reach up to 46.59%. Therefore, cinnamon flavonoids can be studied and developed as natural antibacterial agents in depth.