Abstract
A method for the enantiomeric determination of 2,7,8‐trimethyl‐2‐(β‐carboxyethyl)‐6‐hydroxy chroman (LLU‐α, γ‐CEHC) in rat plasma was developed using high‐performance liquid chromatography (HPLC) with a fluorimetric derivatization with 4‐N, N‐dimethylaminosulfonyl‐7‐piperazino‐2,1,3‐benzoxadiazole (DBD‐PZ) followed by O‐acetylation with acetyl chloride. The proposed HPLC system used two non‐chiral columns (phenyl and octadecylsilica) and a chiral column (a modified cellulose type), which were connected via two column‐switching valves. A derivatized sample prepared from rat plasma was first separated on the phenyl column, and the fraction including LLU‐α derivative was introduced to the octadecylsilica column to quantify the concentration of the mixture of S‐ and R‐LLU‐α. Finally, the LLU‐α derivative was directly injected into the chiral column to obtain the ratio of the enantiomers. The proposed HPLC system was applied to the enantiomeric determination of LLU‐α in plasma after intravenous administration of racemic LLU‐α. S‐LLU‐α was eliminated faster than R‐LLU‐α, and its concentration in plasma decreased to one‐third at 2 min after dosing. Copyright © 2001 John Wiley & Sons, Ltd.
Abbreviations used:
DBD‐PZ
4‐N,N‐dimethylaminosulfonyl‐7‐piperazino‐2,1,3‐benzoxadiazole
DPDS
2,2′‐dipyridinyl disulfide
LLU‐α, γ‐CEHC
2,7,8‐trimethyl‐2‐(β‐carboxyethyl)‐6‐hydroxy chroman
TFA
trifluoroacetic acid
TPP
triphenylphosphine