GC and GC-MS studies on the essential oil and thiophenes from Tagetes patula L.

Abstract

The production and the composition of the compounds (mono-, sesquiterpenes and acetylenic thiophenes) obtained by the steam distillation of Tagetes patula L. have been investigated. The volatile oil was produced by steam distillation. GC was carried out on three types of stationary phase using flame ionization and mass selective detection. Percentage data were calculated by the area normalization method with very good repeatability (RSD below 5%). Oils from flowerheads were rich in beta-caryophyllene (53.5%) and the leaves contained terpinolene in high concentration (21.1%). The main volatile component of the hairy roots and intact roots was 5(3-buten-1-ynyl)-2,2'-bithienyl (BBT) yielding 28.5% and 44.0% in the oils. Three new minor constituents were identified as alpha-guriunene, beta-caryophyllene and (E)-beta-farnesene. A flash chromatographic method was developed for the isolation of thiophenes from a solvent extract of intact roots. The collected fractions were screened by TLC and analyzed by GC-MS. Three thiophene fractions were obtained containing BBT, 5-(4-acetoxy-1-butynyl)-2,2'-bithienyl (BBTOAc) and 5-(4-hydroxy-1-butynyl)-2,2'-bithienyl (BBTOH).