Yukio Saito

Some Phytochemicals and Related Compounds in Vegetables as Potent Inhibitors of Human DNA Topoisomerase II

An established human DNA topoisomerase II inhibitory assay is described, and the screening results for some phytochemicals in vegetables and related compounds that may useful for chemoprevention through food are reported. The assay requires a small amount of sample and is rapid compared to bioassays using cell lines or animals. The topoisomerase II inhibitory assay is useful for screening compounds in vegetables. More than 80 compounds were screened, and 28 compounds were found to be potent inhibitors at the 10 μg/ml level. Many of the phytochemicals commonly found in vegetables are thus useful for chemoprevention.

Studies on Paraffinic Hydrocarbons in Foods and Human Adipose Tissue

In order to make clear the pollution of the marine environment by petroleum, the present study was carried out on paraffine hydrocarbons. As one of the indices of food contaminations by petroleum, the background contents of the hydrocarbons in fishes, meats, and human adipose tissue were determined by using a modified method consisting of chromate oxidation, Florisil column chromatography and FID-gas chromatography. Paraffine hydrocarbons were detected from all of the fishes except shrimps and shortnecked clams. Large amount of pristane was found in sardine, mackerel-pick, and mackerel, as well as some other kinds of normal paraffine hydrocarbons. The peak patterns of the hydrocarbons in every fish and shell fish tested could be devided roughly into 4 groups. Levels of the hydrocarbon accumulation in the marine fishes were generally higher than those in the fresh ones. The peak patterns of the paraffine hydrocarbons in beef, pork, chicken, and chicken liver were characteristic, respectively, but the contents of total paraffine hydrocarbons were in the similar levels. In the meats, the paraffine hydrocarbons with higher molecular weight were detected on gas chromatograms. In human adipose tissue, pristane, n-nonacosane, and n-hentriacontane were observed from all the samples on gas chromatograms with the peaks of a series of paraffine hydrocarbons. The peak patterns of the tissues were quite different from those of the fishes and the meats. (Received November 4, 1976)

Mutagenicity test of rapeseed frying oils

自動フライヤーにてさつま揚を0, 3, 9, 25及び66日間フライした菜種油について, 経日的な変異原活性の測定を行った. 変異原活性は Ames らの Salmonella typhimurium TA98, TA100, TA97, TA102及び小田らのβ-ガラクトシダーゼ活性を指標としたTA1535/pSK1002を用いて検索した. いずれの試料に関しても変異原活性は認められなかった. しかしPOVが8.9と最も高い9日目の菜種油ではβ-ガラクトシダーゼ活性が対照より約1.8倍高かった.

Determination of Diethylene Glycol in Wine by Use of an Extrelut Column

The determination of diethylene glycol (DEG), added illegally to some imported wines, was investigated. The usage of the Extrelut-20 column, filled up with diatomaceous earth, was useful in eliminating interfering substances and water for analyses of many samples without column damage in gas-liquid chromatography (GLC) and for GC/MS measurement with a capillary column. The detection limit of DEG was 5ppm in wine by this method, involving clean-up and GLC with a 20% PEG 20M column or a wide-bore capillary column coated with 50% phenyl methyl silicon. The method was also useful for analysis of DEG in other beverages such as grape juice.