A shock Hugoniot compression curve for water has been measured up to less than 1 GPa. A plane and steady shock wave is produced in water by the flat plate impact of a projectile accelerated by a compressed gas gun. A new experimental procedure was proposed to detect the shock wave front sensitively, which makes it possible to measure shock Hugoniot in higher precision than the previous method. The present method is based on the very large pressure dependence of the refractive index of water upon compression. By using this method, the shock compression curve was determined within the precision of 2% to 3% of the estimated shock pressure. The precision is better than that of the previous data. It was confirmed that within the pressure range covered in this experiment, the shock-particle velocity Hugoniot can be described by a linear relation with a large slope. Shock Hugoniot states on the pressure-temperature plane were calculated by using the obtained Hugoniot data combined with the values of thermodynamical variables. Thermodynamic analysis of the shock compression process was developed to estimate the contributions of irreversible heating by shock compression.

The establishment of international monographs for herbs is in progress. Here, we propose both a marker compound and a method for its analysis for the identification of garlic bulbs and their products. The constituents in 26 kinds of fresh edible parts of Allium vegetables and three types of garlic preparations were analyzed. Sulfur compounds are the most characteristic constituents in garlic, but manufacturing processes of garlic products dramatically affect these constituents. Thus, no sulfur compound could be specified as a universal marker of identification applicable for any type of garlic. On the other hand, garlic contains other characteristic compounds, namely, saponins. After analyzing Allium vegetables and garlic preparations, we concluded that sapogenins, especially beta-chlorogenin, may be a viable candidate for identifying and distinguishing garlic from other Allium vegetables.

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The pharmacological effects of Oren-gedoku-to (OGT), a Japanese-Chinese traditional herbal medicinal mixture on lipid biosynthesis were investigated in cultured human hepatocyte HepG2 cells. The addition of OGT (0.5 and 4.2 mg/ml), which had no effect on cell proliferation and cellular protein content, caused a marked decrease in the cellular cholesterol content, particularly cholesteryl ester content following 24 h incubation. The incorporation of 14C-oleate into cellular cholesteryl ester fraction was also reduced remarkably during incubation for 6 and 24 h. The effects of OGT, its components and its main active chemicals on acyl-coenzyme A:cholesterol acyltransferase (ACAT) activity were studied in vitro to explore the mechanism by which OGT inhibits cholesteryl ester formation. The data confirmed that OGT, in a dose-dependent manner, and its components (Scutellaria baicalensis, Coptis japonica, Gardenia jasminoides and Phellodendron amurense) remarkably inhibit ACAT activity. Among the main active chemicals of OGT, baicalein, a kind of flavonoid, decreased ACAT activity in a dose-dependent fashion from the level of 10(-6)M. These results strongly suggest that OGT reduces the cholesteryl ester formation in human hepatocytes by inhibiting ACAT, and that baicalein may, in part, be responsible for ACAT inhibition.

A simple but novel compound, S-1-methoxy-1-(3,5-dimethoxy-4-hydroxyphenyl)ethane, was isolated as a moderately antioxidative compound from rape (Brassica campestris L. subsp. napus) oil cake together with 5 known compounds. Three of these compounds, indolacetonitrile, 4-hydroxyindolacetonitrile, and 4-hydroxyphenylacetonitrile, showed strong antioxidative activity evaluated by the ferric thiocyanate method.