Preparative HPLC is a profitable technique for receiving usable amounts of substances
from various mixtures. The work presents two ramentaceone isolation procedures from
a chloroform extract obtained from Drosera aliciae Raym.-Hamet (Droseraceae) cultured in vitro using normal- and reversed-phase preparative liquid chromatography (NP-, RP-PLC).
A LiChroprep RP-18, 12µm, 250×16.8mm column and mixture of methanol: water 8:2 v/v
as solvent were used in the reversed phase mode. Samples of plant extracts were also
separated using a LiChrosorb silica gel column (200×16.8mm, 10µm) and a mixture of
n- hexane/methyl t-butyl ether 9:1 v/v was used as mobile phase (NP-PLC). The mobile
phase flow rate was 7 mL/min (in the reversed phase mode) and 5mL/min (in the normal
phase mode). The HPLC column was backflushed after elution of ramentaceone in each
analysis to remove strongly adsorbed compounds. Step elution is an alternative to
backflush, however, it requires activation of the PLC column. For a specified purity
of products the maximum level of column overloading, efficiency of process and productiveness
of PLC- columns were compared. The process efficiency was defined as an amount of
received substance in a unit of time. Under the NP-PLC conditions we received about
10mg ramentaceone of 99,80% purity in one experiment and under the RP-PLC conditions
2mg of 92,50% purity. Run time was 60min and 40min for NP-PLC and RP-PLC, respectively.
Productiveness of the PLC- column was defined as an amount of substance of maximum
purity received in unit of time in relation to column cross section area. Productiveness
of NP-PLC column was found to be 4,5µg/cm2min, concerning the the RP-PLC column it was only 1,3µg/cm2min.
Acknowledgements: State Committee for Scientific Research, Grant No KBN 0430/P04/2004/26
