Simultaneous determination of β-elemene, curcumol, germacrone and neocurdione in olatile oil of Curcuma phaeocaulis and vinegar products by GC-MS Comparison on four sesquiterpenes in volatile oil of differently-processed Curcuma Rhizoma Determination of curdione, curcumol, germacrone, and β-elemene in processed Curcumae Rhizoma from different habitats Studies on Chemical Constituents of Curcuma aromatica Salisb. Chemical constituents in roots and rhizomes of Curacuma aromatica Comparison of content of curdione, curcumol, germacrone and β-elemene in different varieties of vinegar backed Rhizoma Curcuma Comparison on four sesquiterpenes in volatile oil of differently-processed Curcuma Rhizoma