Abstract
Reversed-phase high Performance liquid chromatography (C18-HPLC) was used to separate
and quantitate all the detectable alkyl and alkenyl thiosulfinates, including configurational
isomers, of garlic homogenates. Pure thiosulfinates were synthesized or isolated and
identified by 1H-NMR, and their extinction coefficients determined. Some configurational isomers
required Separation by silica-HPLC. Five previously unreported thiosulfinates have
been found, four of which contain the trans-1-propenyl group and increase several-fold to over half the content of allicin upon
storage of garlic bulbs at 4°C with a concomitant decrease in a γ-glutamyl peptide.
The variation in thiosulfinate yield between different countries, stores, bulbs, cloves,
and storage times was investigated. A method for standardizing the quantitation of
allicin yield from garlic is proposed and compared to other methods of allicin analysis.
Key words
Allicin - alkyl and alkenyl thiosulfinates -
Allium sativum
- garlic - RP-HPLC
