Isolation of bioactive components from Flaveria bidentis (L.) Kuntze using high-speed counter-current chromatography and time-controlled collection method

Semipreparative high-speed counter-current chromatography (HSCCC) by time-controlled collection method was successfully applied for isolation and purification of α-terthienyl, 5-(3-buten-1-ynyl)-2,2'-bithienyl, and 5-(3-penten-1-ynyl)-2,2'-bithienyl from Flaveria bidentis (L.) Kuntze for the first time. The two-phase solvent system composed of n-hexane and acetonitrile at the volume ratio of 1:1 (v/v) was used for the semipreparative HSCCC. The 5.2 mg α-terthienyl, 2.2 mg 5-(3-buten-1-ynyl)-2,2'-bithienyl, and 4.3 mg 5-(3-penten-1-ynyl)-2,2'-bithienyl with the purity of 99.9, 90.2, and 92.1% were produced from 265.6 mg crude extract, respectively, and 5-(3-penten-1-ynyl)-2,2'-bithienyl was first isolated from Flaveria bidentis (L.) Kuntze. The structures of the separated compounds were identified by electrospray-ionization mass spectrometry and proton and carbon nuclear magnetic resonance ((1)H- and (13)C-NMR).