Separation of a triterpenoid saponin mixture from Maesa lanceolata: semipreparative reversed-phase wide pore high performance liquid chromatography with temperature control

A mixture of triterpenoid saponins derived from the dried leaves of Maesa l anceolata was separated, without structure deterioration, in its components . Seven fractions (I-VII) of high molecular weight (1234-1358) saponins wer e obtained on a semipreparative scale using wide pore reversed-phase high p erformance liquid chromatography with an acetonitrile-trifluoroacetic acid (500:0.3 w/w-)-water-trifluoroacetic acid (391:0.3, w/w) gradient from 35 t o 56% in 30 min. The mobile phase was cooled in an ice bath (0 degrees C) d uring chromatography in order to prevent bubble formation and to improve th e quality of the separation. Freeze-dried fractions IV, V, VI and VII were further separated using solvent systems developed for each of the fractions . Fourteen pure triterpenoid saponins were isolated in this way and their m olar weight determined. (C) 1998 Elsevier Science B.V. All rights reserved.