祁白术生物活性物质及其抗氧化、抑菌能力研究

摘要

研究祁白术甲醇粗提物及其不同极性萃取相的总酚、总黄酮含量及抗氧化、抑菌活性,考察总酚、总黄酮含量与抗氧化活性的相关性,并采用气相色谱-质谱联用(GC-MS)分析醇提物中的主要化学成分.结果表明,祁白术不同极性萃取相(正己烷相、二氯甲烷相、乙酸乙酯相、正丁醇相和水相)的总酚、总黄酮含量及其抗氧化、抑菌能力存在显著差异(P＜0.05).乙酸乙酯相的总酚和总黄酮含量最高,分别为(139.45±0.19) mg TA/g和(21.28±2.28) mgQE/g.乙酸乙酯相表现出最强的还原能力[(38.95±1.66) mg Vc/g]、ABTS自由基清除能力[(302.42±7.51) mg Vc/g]、DPPH自由基清除能力[(51.61±2.59) mg Vc/g].祁白术的总酚、总黄酮含量均与还原能力、ABTS自由基清除能力及DPPH自由基清除能力呈显著正相关(P＜0.05).甲醇粗提物及正己烷相、二氯甲烷相对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌和绿脓杆菌均具有不同程度的抑制作用,其中正己烷相的抑菌活性最为显著,其对4种受试菌的最小抑菌浓度均为1 mg/mL.GC-MS分析了醇提物的主要化学成分,共鉴定出18种化合物,以酚、醇、烯、酮类化合物为主,主要成分有3,3'二氨基-4,4'-二羟基联苯(33.47％)、β桉叶醇(28.33％)、β-愈创木烯(5.91％)、3,3,5,6,7-五甲基-1-茚满酮(4.70％)等.%The total contents of phenolics and flavonoids and the relativeantioxidant and antibacterial activities in different polarity fractions from Atractylodes macrocephala Koidz grown in Qimen (Qi Baizhu) were evaluated.The correlation between total phenolic,flavonoid contents and the antioxidant activities were analyzed.The main constituents of methanol crude extract were identified by gas chromatography-mass spectrometry (GC-MS).The results showed that there were significant differences in the contents of total phenolics and flavonoids,antioxidant and antibacterial activities among different polarity fractions including n-hexane,dichloromethane,ethyl acetate,n-butanol and water fractious (P ＜ 0.05).The ethyl acetate fraction had the highest contents of total phenolics [(139.45 ± 0.19) mg TA/g] and total flavonoids [(21.28± 2.28) mg QE/g].Moreover,it exhibited the strongest reducing power [(38.95-t-1.66) mg Vc/g],ABTS radical scavenging ability [(302.42± 7.51) mg Vc/g],and DPPH radical scavenging ability [(51.61±2.59) mg Vc/g].The contents of total phenolics and flavonoids demonstrated significant correlations with antioxidant activity (P＜0.05).The methanol extract,n-hexane and dichloromethane fractions exerted potent inhibitory effects on E.coli,S.aureus,B.subtilis and P.aeruginos.Hexane fraction presented the best antibacterial effect,and its minimum inhibitory concentration against four common bacterial strains was 1 mg/mL.The methanol crude extract was analyzed by GC-MS,and eighteen compounds were identified,including phenols,alcohols,alkenes and esters,and the major constituents were found to be 3,3'-diamino-4,4'-dihydroxybiphenyl (33.47％),β-eudesmol (28.33％),β-guaiene (5.91 ％),and 3,3,5,6,7-pentame-thyl-2 H-inden 1-one (4.70 ％).