Hiromitsu Aoki

Carotenoid Pigments in GAC Fruit (Momordica cochinchinensis SPRENG)

The carotenoids in Gac fruit (Momordica Cochinchinensis spreng) were analysed by high-performance liquid chromatography (HPLC), and the concentrations of β-carotene, lycopene, zeaxanthin and β-cryptoxanthin were measured. Lycopene was found to be predominantly present in the Gac seed membrane at a concentration of up to 380 μg/g of seed membrane. The concentration of lycopene in the Gac seed membrane was about ten-fold higher than that in known lycopene-rich fruit and vegetables, indicating that Gac fruit could be a new and potentially valuable source of lycopene.

Absence of liver tumor promoting effects of annatto extract (norbixin), a natural carotenoid food color, in a medium-term liver carcinogenesis bioassay using male F344 rats

Modifying potential of annatto extract (norbixin) on liver carcinogenesis was investigated in male F344/DuCrj rats initially treated with N-nitrosodiethylamine (DEN). Two weeks after a single dose of DEN (200 mg/kg, intraperitoneally), rats were given annatto extract at dietary levels of 0, 0.03, 0.1 and 0.3%, or phenobarbital sodium at 0.05% as a positive control for 6 weeks. All animals were subjected to partial hepatectomy at week 3, and were killed at week 8. There were no deaths related to annatto extract ingestion, and the treatment had no effects on body weights, or food and water consumption. Statistically significant increases of absolute and relative liver weights were apparent in the 0.1 and 0.3% groups. However, annatto extract did not significantly increase the quantitative values for glutathione S-transferase placental form positive liver cell foci observed after DEN initiation, in clear contrast to the positive control case. The results thus demonstrate that annatto extract at a dietary level of 0.3% (200 mg/kg/day) lacks modifying potential for liver carcinogenesis in our medium-term bioassay system.

Analytical and Preparative Separation of Kaoliang and Lac Colors by pH‐Zone‐Refining CCC

Abstract The natural coloring agents Kaoliang and Lac colors were separated using pH‐zone‐refining countercurrent chromatography (pH‐z‐CCC) on an analytical or preparative scale. The main components of Kaoliang color have been reported to be apigeninidin and luteolinidin, however, the structures of other compounds present in the color have not been elucidated as it is difficult to separate the compounds using conventional chromatographic techniques. Therefore, the separation of this color was done by pH‐z‐CCC that isolated three compounds. LC/MS and 1H‐NMR analyses were used to determine the structures established as a halogenated phenyl compound, p‐coumaric acid and methylated apigenin. Lac color mainly consists of four anthraquinone derivatives, named laccaic acid A, B, C, and E. These four laccaic acids were separated on a large scale by pH‐z‐CCC. Purified Lac color (1 g) was submitted to pH‐z‐CCC with tridodecylamine as a ligand, and produced 790 mg, 41 mg, 109 mg, and 6 mg of laccaic acid A, B, C, and D, respectively, with a minimum purity of 96%.