GC-MS studies of thiophenes in the supercritical fluid CO_2 and solvent extracts of tagetes patula L.

摘要

The intact plant parts and genetically modified hairy root clone #TpA6 of Tagetes patula were extracted with supercritical fluid CO_2 extraction (SFE) and a conventional solvent extraction. SFE optimization included the variation of fluid CO_2 pressure, dynamic time, and the addition of methanol modifier co-solvent. The four characteristic thiophene metabolites, 5-(3-buten-1-ynyl)-2,2′-bithienyl (BBT), 2,2′:5′,2″- terthiophene (α-T), 5-(4-acetoxy-1-butynyl)-2,2′-bithienyl (BBTOAc), and 5-(3,4-diacetoxy-1-butynyl)-2,2′-bithienyl [BBT(OAc)_2], were analysed by GC-MS. The proposed SFE method allowed the selective extraction of thiophenes in 60 min dynamic time with supercritical CO_2 without modifier co-solvent, at 30 MPa and 40 °C. The SFE and the reference solvent extraction yielded similar results. The SFE of intact roots and flowers yielded 717 ± 31.3 and 480 ± 26.6 μg g~(-1) α-T, respectively, while the leaves did not contain considerable amounts of thiophenes. Remarkable amounts of BBT, BBTOAc, and BBT(OAc)_2 were characteristic of the SFE of hairy root cultures.