Yoko Kawasaki

IC/ICP-MSによるパン中臭素酸カリウムの特異的分析法

A sensitive method for detecting bromate in bread by ion chromatography with inductively-coupled plasma mass spectrometry (IC/ICP-MS) was developed. Bromate was extracted from bread with water. The clean-up procedure included a 0.2 micron filter, a C18 cartridge for defatting, a silver cartridge to remove halogen anions, a centrifugal ultrafiltration unit to remove proteins, and a cation-exchange cartridge to remove silver ions. A 500 microL sample solution was applied to IC/ICP-MS. The detection limit and the quantitation limit of bromate in the solution were 0.3 ng/mL and 1.0 ng/mL, expressed as HBrO3, respectively, which corresponded to 2 ng/g and 5 ng/g, respectively, in bread. Recovery of bromate was about 90%, and the CV was about 2%. Based on the detection limit in solution and recovery from bread, the detection limit of bromate in bread was estimated to be 2 ng/g.

Oxomollugin, a potential inhibitor of lipopolysaccharide-induced nitric oxide production including nuclear factor kappa B signals

Mollugin, a naphthoquinone derivative, was reported to possess various biological activities such as anti-inflammatory and anti-tumor activity. Mollugin isolated from Rubia tinctorum roots inhibited lipopolysaccharide-induced nitric oxide (NO) production in RAW264.7 macrophages. However, mollugin synthesized for further investigation of its anti-inflammatory mechanism showed weak activity in addition to unstable assay results. From the result of analysis on a degradation product of mollugin, oxomollugin was found to be the main active substance of mollugin degradation, showing a potent inhibitory activity on NO-production including nuclear factor kappa B signals.

Syntheses and anti-inflammatory activity of azamollugin derivatives

Oxomollugin (2) is a degradation product of mollugin (1) and a potent inhibitor of NO-production including nuclear factor kappa B signals. In our endeavor to develop a potent anti-inflammatory compound, we synthesized several aza-derivatives of oxomollugin (2) and evaluated their NO-production inhibitory activity. Azamollugin (3) showed a potent inhibitory activity, and its activity (IC50 0.34μM) was proved to be more potent than that of oxomollugin (2, IC50 1.3μM).