埃及产百里香和牛至精油、提取物的抗氧化和抗菌活性研究

Antioxidant and antimicrobial activities of essential oils and extracts of thyme (Thymus vulgaris L.) and oregano (Origanum vulgare L.) plants grown in egypt

[目的]本文对埃及产的百里香(Thymus vulgaris L.)和牛至(Origanum vulgare L.)的化学成分、抗氧化和抗菌活性进行了研究。[方法]本文采用GC-MS法和福林酚方法对样品中的化学成分和多酚物质进行了分析,同时使用DPPH试剂和抑菌圈实验评价样品的抗氧化和抗菌效果。[结果]埃及产百里香精油中主要含有百里香酚(45.19%)、p-伞花烃(13.59%)、香芹酚(7.65%)和松油烯(6.82%),牛至精油中主要有香芹酚(52.46%)、松油烯-4-醇(7.43%)、顺-β-萜品醇(5.64%)和松油烯(4.73%)。百里香和牛至的精油中的多酚含量分别为228.78 mg/g和129.43 mg/g,表现出显著的DPPH自由基清除能力,而残渣中的多酚含量相对较少(123.68 mg/g和138.26 mg/g),但抗氧化能力要更强。在抗菌能力方面,两种提取物均对Klebsiella pneumonia(35.8±0.89)mm和(37±0.47)mm的抑制能力最强,而百里香和牛至的精油则分别对Rhodotorula mucilaginosa(25.7±0.27)mm和Aspergillus flavus(16.5±0.24)mm。[结论]埃及产百里香和牛至均具有明显的抗氧化和抗菌活性。

[Objective]The chemical compositions as well as the antioxidant and antimicrobial activities of thyme(Thymus vulgaris L.)and oregano(Origanum vulgare L.)cultivated in Egypt were evaluated.[Methods]GC-MS and Folin-Ciocalteau method were used to analyze the compositions of the essecntial oils and total phenolic of extracts and essential oils from the two plants,respecitively.Then DPPH radical scavenging assay and Bactericidal test were used to evaluate the antioxidant and antimicrobial activities of the samples.[Results]The results indicated that the major constituents of the thyme essential oil were thymol(45.19%),p-cymene(13.59%),carvacrol(7.65%)andγ-terpinene(6.82%),while carvacrol(52.46%),terpine-4-ol(7.43%),terpineol,cis-β(5.64%)andγ-terpinene(4.73%)were the major components of oregano essential oil.The essential oils of thyme and oregano contained appreciable levels of total phenolic contents(228.78 mg/g and 129.43 mg/g)and showed good activity in DPPH radical scavenging with IC50(68.95 mg/mL and 96.47 mg/mL).Both extracts contained lower total phenolic contents(123.68 mg/g and 138.26 mg/g)than the essential oils but exhibited very strong DPPH radical scavenging capacity with IC50(0.438 mg/mL and 0.984 mg/mL,respectively).In addition,extracts and the essential oils exerted great antimicrobial effects against human and plant pathogenic microorganisms.Klebsiella pneumonia was the most sensitive microorganism of oregano and thyme extracts(200μg/mL)with(35.8±0.89)mm and(37±0.47)mm inhibition zones,respectively.Thyme essential oil had the highest effect on Rhodotorula mucilaginosa with(25.7±0.27)mm,while oregano(16.5±0.24)mm on Aspergillus flavus.[Conclusion]Thyme and oregano extracts and essential oils represent good natural sources of antioxidant and offer strong antimicrobial properties against human and plant pathogenic microorganisms.