New Zealand mānuka (Leptospermum scoparium) honey is known to exhibit non-peroxide antibacterial activity caused by the active ingredient methylglyoxal which arises by chemical conversion of dihydroxyacetone during honey maturation. This study determines whether methylglyoxal and dihydroxyacetone are present in Australian Leptospermum honeys. This research developed a rapid and sensitive high-performance liquid chromatographic method for the concurrent analysis of methylglyoxal and dihydroxyacetone in honeys. Both compounds were quantified as their O-(2, 3, 4, 5, 6-pentafluorobenzyl) hydroxylamine. HCl derivatives on single run reversed phase high-performance liquid chromatography with diode array detection. Four species of monofloral Leptospermum honeys sourced from Northern Rivers Region, New South Wales, Australia contained methylglyoxal and dihydroxyacetone. The highest methylglyoxal concentrations were found in Leptospermum polygalifolium honeys.
Journal of Pharmacognosy and Phytotherapy / Vol. 4, No. 1, pp.6-11