Extraction Methods And Antioxidant Effects Of Boswellia Papyrifera (Del.) Hochst Extracts

Frankincense is a famous ancient medicinal material with rich pharmacological activity and high research value.And so far there are few reports on the extraction methods,chemical composition and antioxidant effect of Boswellia papyrifera（Del.）Hochst.The study extracted the B.papyrifera（Del.）Hochst resin through three extraction methods,and the antioxidant efficacy of three extracts were evaluated in vitro and cellular level.Then the chemical components of three extracts were analyzed by GC-MS and UPLC&Q-TOF MS method,and the main active substance were preliminarily determined.The research can provide theoretical support for the development and application of B.papyrifera（Del.）Hochst extracts,which has important significance for its application in antioxidant cosmetics.The results can mainly conclude as follows:1.During the extraction of B.papyrifera（Del.）Hochst essential oil,prolong the extraction time can obtain higher yield of B.papyrifera（Del.）Hochst essential oil,and the optimized essential oil contains more anti-oxidant active substances.In the extraction process of ethanol extract,the solvent concentration has the greatest influence on the yield of ethanol extract.And the optimal extraction conditions were:100%ethanol,62.5 ^oC,2 h,with a 38.17%yield of ethanol extract.2.The main chemical components of the essential oil extracted by traditional hydrodistillation are（S,E）-8,12,15,15-Tetramethyl-4-methylene bicyclo[9.3.1]pentadeca-7,11-diene（28.70%）,acetic acid octyl ester（19.86%）,incensole isomer（14.36%）,incensole（9.08%）.The main components of the essential oil extracted by optimized hydrodistillation are（S,E）-8,12,15,15-Tetramethyl-4-methylenebicyclo[9.3.1]pentadeca-7,11-diene（19.65%）,incensole isomer（19.33%）,incensole（15.45%）,24-Norursa-3,12-dien-11-one（12.47%）.The main volatile components of the ethanol extracts are incensole（32.08%）,incensole isomer（21.71%）,（S,E）-8,12,15,15-Tetramethyl-4-methylenebicyclo[9.3.1]pentadeca-7,11-diene（12.56%）.The main non-volatile components of the ethanol extracts are elemonic acid,α-boswellic acid,β-boswellic acid,acetylβ-boswellic acid.3.The possible antioxidant active substance maybeα-pinene,octyl chloroformate,ethyl laurate,tetradecanoic acid ethyl ester,ethyl palmitate,aromadendrene,cembrene,cembrenol,incensole,incensole isomer,valerenol,24-Norursa-3,12-dien-11-one,α-amyrin andα-boswellia acid.And only the ethanol extracts containedα-boswellia acid.The antioxidant active substances in ethanol extracts accounted for 58.43%of the total content of volatile components,and 50.84%as well as 25.18%of the total content of volatile components in optimized and traditional essential oil were antioxidant active substances,respectively.4.In combination,the three extracts all have antioxidant capacity in vitro and in cellular level.And there were significance differences in the antioxidant capacity of three extracts in vitro.In the reducing power test,DPPH and super oxygen anion scavenging test as well as total antioxidant capacity test,the ethanol extracts showed a better performance,the next was the optimized essential oil and the traditional essential oil was the weakest.But in the hydroxyl scavenging test,the optimized essential oil showed the best,the ethanol extracts came second and the traditional essential oil was the weakest.In cellular level,three extracts can reduce the ROS content induced by H₂O₂ in HaCaT cells,and increase the proliferation rate of HSFB.And there was no significant difference in antioxidant capacity among three extracts.