Two new germacrane-type sesquiterpenoids from resin of Commiphora mukul Quality analysis and evaluation of myrrh Comparison between SEF-C02 extraction and traditional Methods for extracting essential oil components in myrrh Quality analysis and evaluation of myrrh Studies on the Constituents of Essential Oil of Imported Myrrh and Gum Opoponax Resource and ecological distribution of ectomycorrhizal fungi under pine forests of Huangshan Mountain district Comparison between SEF-CO2 extraction and traditional methods for extracting essential oil components in myrrh