Composition analysis,antioxidative and antibacterial activities comparison of agarwood oils extracted by supercritical and steam distillation / 中国中药杂志

Agarwood is a traditional and precious medicinal material and natural spice in China and other southeast Asian countries.As the head of all spices,agarwood has many pharmacological activities such as analgesia,antidiarrheal,anti-inflammatory and antibacterial effects. Due to its high price and scarce resources,there were just a few previous studies on it,mainly focusing on the chemical compositions of the agarwood essential oil and solvent extract mixture. The components of agarwood oils obtained by supercritical extraction and steam distillation were analyzed by using Gas Chromatography-Mass Spectrometer( GC-MS),and then the agarwood oils compositions and contents were compared between the traditional extraction method and the recently emerging supercritical extraction method. Antioxidant experiments of scavenging DPPH,ABTS,hydroxyl radical,total reducing power and MIC experiments of five kinds of tester strains such as staphylococcus aureus were combined to illustrate the differences between these two kinds of agarwood oils in terms of antioxidant and bacteriostatic activities. The results showed that the main components of agarwood oil were sesquiterpenoids( 68. 68%) in steam distillation extraction method,but sesquiterpenoids( 23. 78%) and chromones( 29. 42%) in supercritical extraction method. Fourteen common components included benzyl acetone,α-santalol,γ-eudesmol,agarospirol and guaiol etc. The antioxidant activity and inhibitory MIC of agarwood oils in supercritical extraction method were better than those in steam distillation method,and the inhibitory effect of agarwood oil on the growth of bacillus subtilis was found for the first time.

Correlations between antioxidant activities and contents of total flavonoids and total phenols of four extracts from Nervilia fordii / 中成药

AIM To investigate the correlations between antioxidant activities and contents of total flavonoids and total phenols of chloroform,ethyl acetate,n-butanol and ethanol extracts from Nervilia fordii (Hance) Schltr..METHODS The contents of total flavonoids and total phenols in four extracts from N.fordii were determined by AlCl3-HAc-NaAc coloration method and Folin-Ciocalteu colorimetric method,respectively.The antioxidant activities of extracts were evaluated by determining scavenging activities of DPPH radical,hydroxyl radical and ABTS radical,together with reducing power.Then the correlations between antioxidant activities and contents of two constituents were analyzed by SPSS17.0 software.RESULTS The antioxidant activities of four extracts from N.fordii all showed dose-effect relationships,that of ethyl acetate extract was the strongest,while that of ethanol extract was the weakest.They had some correlations with the content of total flavonoids (0.604 ＜ r ＜ 0.638) and significant correlations with the content of total phenols (r ＞ 0.977).CONCLUSION Ethyl acetate extract from N.fordii can be used for the development of natural antioxidants,and the content of total phenols is the main factor to influence its antioxidant activity.