Enantiomeric purity determination of acetyl-L-carnitine by reversed-phase high-performance liquid chromatography using chiral derivatization.

An indirect HPLC enantioseparation method for the determination of acetyl-D-carnitine (D-AC) in acetyl-L-carnitine (L-AC) was developed. L-AC was derivatized with a chiral amino compound which has a chromophore for UV detection. Six chiral amino compounds were examined as chiral derivatization reagents. Among them, enantiomers of acetylcarnitine derivatized with L-alanine-beta-naphthylamide (L-Ala-beta-NA) were successfully separated on an ODS column within 10 min with Rs = 1.94 and alpha = 1.10. Quantitation was achieved through UV detection at 254 nm. The derivatization reaction of L-AC with L-Ala-beta-NA was completed in less than 10 min at room temperature (ca. 20 degrees C). Validation data such as linearity, detection limit, and precision are also presented. The detection limit of D-AC in L-AC in this method was below 0.05% (visual evaluation). This method was found to be applicable as a practical quality control method for the enantiomeric purity determination of L-AC.

[Studies on the chemical constituents of Aconitum szechenyianum Gay].

Five constituents were isolated from Aconitum szechenyianum Gay. The structures of these compounds were identified as beta-sitosterol (I), aconitine (II), 3-acetylaconitine (III), songorine (IV) and a new compound whose structure was elucidated to be szechenyine (V) on the basis of UV, IR, 1HNMR, 13CNMR and Mass spectra.

A preparation and purification of [1-14C]acetylcarnitine.

[1-14C]Acetylcarnitine was prepared from [1-14C]acetate and L-carnitine using acetyl-CoA synthetase and carnitine acetyltransferase. The product was purified by ion-exchange and thin-layer chromatography. Conversion of [1-14C]acetate to [1-14C]acetylcarnitine was better than 90% and overall recovery of the pure product was greater that 80%.