Abstract
The procedure for allicin synthesis could be improved. The time for HPLC analysis
of allicin was shortened by the application of different isocratic elution systems.
Calibration was performed by use of an allicin/silica gel adsorbate as external standard
and its allicin content could be confirmed by different methods. L-(+)-Alliin was synthesized and applied as external standard for the quantitative
determination of alliin by HPLC. Diastereoisomers had been separated by repeated recrystallization.
Fresh Allium sativum bulbs from different origins were analyzed with respect to allicin content after
complete enzymatic conversion of alliin; allicin contents found were in the range
of 0.4%. The corresponding alliin contents were in the range of 0.9%. For a comparative
evaluation of the alliin- and the allicin-HPLC determination methods, commercially
available garlic preparations were analyzed, demonstrating that both methods are appropriate.
However, the application of the HPLC system for allicin determination, in addition
to providing information on the alliin-dependent allicin-generating capacity, enables
the simultaneous quantification of allicin transformation products, such as ajoenes,
dithiins, and alkyl sulfides. It was found that, for quantitative GLC analysis of
allicin, allicin has to be used as an external standard.
Key words
Allium sativum
- allicin - alliin - HPLC - quantitative analysis
