Oyster Extract "Research" for your good health!

The 19th Symposium on Trace Nutrients Research(2002)
Special Session Kyoto, May 25, 2002

ThemeReporterPositionP
Special Session
Nutrition Delivery System - A New Concept of Iron Fortification in Foods -
Lekh Raj Juneja, Noboru Sakaguchi Nutritional Foods Division Taiyo Kagaku Co., Ltd. Japan 1-

Proceedings

NOThemeReporterPositionP
1 Evaluation of absorption processes of vanadium compounds by ESR Jun Fugono, Hiroyuki Yasui, and Hiromu Sakurai Dep. of Analytical and Bioinorganic Chemistry, Kyoto Pharmaceutical Univ. 11-
2 Role of NifS homologs in selenium metabolism Hisaaki Mihara(1),Shin-ichiro Kato(1),Gerard M. Lacourciere(2),Thressa C. Stadtman(2),Tatsuo Kurihara(1),Umechiyo Tokumoto(3),Yasuhiro Takahashi(3),and Nobuyoshi Esaki(1) (1)Institute for Chemical Research, Kyoto University
(2)Laboratory of Biochemistry, NHLBI, National Institutes of Health
(3)Department of Biology, Graduate School of Science, Osaka University
15-
3 Effect of iron and aluminum on growth of unicellular eukaryote Euglena gracilis Z Chie Higashio(1),Masahiro Kohno(2),Tetsuya Suzuki(1) (1) Graduate School of Fisheries Science, Hokkaido University
(2) Department of Environmental Systems Engineering, Kochi University of Technology
19-
4 Comparative study on the growth inhibition and metabolism of sodium arsenite in Euglena gracilis strains Z and SMZ Akiko Suzuki (1),Toshikazu Kaise(2),Masumi Watanabe(1) and Tetsuya Suzuki(1) (1) Graduate School of Fisheries Science, Hokkaido University
(2) Department of Environmental Systems Engineering, Kochi University of Technology
23-
5 Arsenic Metabolites Excreted into the Human Urine after Hijiki Intake Masayuki Katayama(1),Yohko Sugawa-Katayama(2),Chie Sakiyama(2),Yukie Kouya(2),Chiduru Furukawa(2)and Ken'ichi Hanaoka(3) (1)Osaka Prefecture University
(2)Department of Human Health Science, Graduate School of Human Environment Sciences, Fukuoka Women's University
(3)Department of Food Science and Technology, National Fisheries University
27-
6 The reproductive toxicity of organotin on the mammalian species Hirofumi T. Suzuki, Yasuko Otani, Chiharu Ono,Nao Murayama, Chikako Yamaguchi,Maiko Kuroda, Rieko Oba, Yasuaki Arakawa Department of Hygiene & Preventive Medicine, Faculty of Health Science, The University of Shizuoka 35-
7 Effects of low level tributyltin chloride on DNA in Euglena gracilis Z and SMZ strains Tomo Kawamura(1),Takahiko Higasa(2),Mikio Fujioka (3), Mari Ohta(1),Masumi Watanabe(1) and Tetsuya Suzuki(1) (1) Hokkaido University, Graduate School of Fisheries Science
(2) Kyoto University, Graduate School of Agricultural Science
(3) Kyoto University, Graduate School of Medical Science
39-
8 Characteristics of Zinc-rich Fraction Prepared from Oyster Munehiro Yoshida(1),Noboru Hirata(1),Sachiko Kitani(1),Yoshikazu Matsuda(2) (1) Laboratory of Food and Nutritional Sciences, Faculty of Engineering, Kansai University
(2) Japan Clinic Co., Kyoto, Japan
43-
9 Suppression of UVA-induced skin damage by topical application of zinc(II) chloride -In vivo real-time chemiluminescent assay- Hiroyuki Yasui and Hiromu Sakurai Department of Analytical and Bioinorganic Chemistry, Kyoto Pharmaceutical University 47-
10 Influence of NaFeEDTA and ferrous sulfate on the absorption of trace elements in rats everted intestinal segments Kaori Igarashi(1,2),Yukiko Nakanishi(1),Rieko Hirunuma(2),Shuichi Emoto(2),Shuichi Kimura(1) (1) Graduate School of Human Life Sciences, Showa Women's University
(2) RIKEN
51-
11 Preparation and characterization of antibody against glycyl-L-histidyl-L-lysine-copper (II) complex Takaji Sato,Tomoko Haraguchi, Yoshihiro Saito and Masahiko Chikuma Osaka University of Pharmaceutical Sciences 55-
12 Dietary Intakes of Folate In Young Women Kazu Suzuki(1),Yuuko Higasine(2),Yosiko Itou(3),Yukiko Yamada(1),Sakiyo Koseki(1),Toyoko Okuda(4) (1)Seibo Jogakuin Junior College
(2)Osaka Shoin Women's College
(3)Osaka Aoyama Junior College
(4)Osaka Kyoiku Universityy
59-
13 Gender differences in Vitamin K of rat plasma and brain Atsuko Takeda(1,2), Hidekazu Hiraike (1,3), Naoki Hatsuda(3), Natsumi Ueno(1), Masayo Imanishi(1), Ryuji Takeda(1), Takahisa Takeda(1,3), Hiroshi Tamai(2), Mieko Kimura(1,3) (1)Takeda Research Institute of Life Science
(2)Osaka Medical College
(3)Graduate School of Medicine, Kyoto University
67-
14 Change of free amino acid and mineral contents during the maturation of Murasakizukin, immature black soybean. Onkoo Rhee(1),Takeshi Kawai(2),Hideki Tsuboi(3),Masao Wada(1),Kenji Sato(1),Takahisa Minamide(1),Kimiko Ohtani(1) (1)Department of Food Sciences and Nutritional Health, Kyoto Prefectural University
(2) Kyoto Prefectural Agricultural Research Institute
(3)Hitachi Science Systems. Ltd.
71-
15 Antioxidant action of xanthurenic acid : Inhibition of lipid peroxidation and protection for NADP-isocitrate dehydrogenase Keiko Murakami, Toshiko Makino, Miyako Haneda and Masataka Yoshino Department of Biochemistry, Aichi Medical University School of Medicine 77-
16 Zinc-containing Thermostable Alcohol Dehydrogenase with Low Substrate Specificity, and Aldehyde Dehydrogenase from Psychrophile, Cytophaga sp. KUC-1: Characterization and Application to Alcohol Determination Takayuki Kazuoka,Ikuo Muraoka,Yoshihiro Yoshida,Noriyuki Kanzawa,Noriaki Arakawa, Tadao Oikawa and Kenji Soda Faculty of Engineering, Kansai University 83-

SUMMARY 1

NO 19-1
Theme Evaluation of absorption processes of vanadium compounds by ESR
Reporter Jun Fugono, Hiroyuki Yasui, and Hiromu Sakurai
Position Department of Analytical and Bioinorganic Chemistry, Kyoto Pharmaceutical University
Volume The 19th Symposium on Trace Nutrients Research(2001)
P P.11-18
Summary Vanadium with insulinomimetic action exists as vanadyl and vanadate species in nature. Recently, vanadyl sulfate (VOSO4) and sodium vanadate (NaVO3) have been examined clinically to find whether they improve human diabetes mellitus (DM). In 2001, it was reported that DM has been improved by the treatment of VOSO4, in which plasma vanadium level during VS treatment was found to correlate with insulinomimetic activity. Therefore, we studied the absorption processes of VOSO4 and NaVO3 with respect to total vanadium as well as vanadyl levels in the blood by using electron spin resonance (ESR). Four blood concentration curves for the two compounds exhibited two absorption maxima, indicating that more than two absorption sites of ionic vanadium compounds exist in the gastro intestine. Bioavailability of NaVO3 was higher than that of VOSO4, indicating vanadyl is less toxic than vanadate

SUMMARY 2

NO 19-2
Theme Role of NifS homologs in selenium metabolism
Reporter Hisaaki Mihara(1), Shin-ichiro Kato(1), Gerard M. Lacourciere(2), Thressa C. Stadtman(2), Tatsuo Kurihara(1), Umechiyo Tokumoto(3), Yasuhiro Takahashi(3), and Nobuyoshi Esaki(1)
Position (1)Institute for Chemical Research, Kyoto University
(2)Laboratory of Biochemistry, NHLBI, National Institutes of Health
(3)Department of Biology, Graduate School of Science, Osaka University
Volume The 19th Symposium on Trace Nutrients Research (2002)
P P.15-18
Summary Three NifS-like proteins, IscS, CSD, and CsdB, from Escherichia coli catalyze the removal of sulfur and selenium from L-cysteine and L-selenocysteine, respectively, to form L-alanine. These enzymes are proposed to deliver a sulfur atom for iron-sulfur cluster, thiamin, 4-thiouridine, biotin, and molybdopterin. It was reported that selenium mobilized from free selenocysteine is incorporated specifically into a selenoprotein and tRNA in vivo, supporting the involvement of the NifS-like proteins in selenium metabolism. We here report evidence that a strain lacking IscS is incapable of synthesizing mnm5se2U and its precursor mnm5s2U in tRNA, suggesting that the sulfur atom released from L-cysteine by the action of IscS is incorporated into mnm5s2U. The lack of IscS also caused a significant loss of the selenium-containing formate dehydrogenase H. Together, these results suggest a dual function of IscS in sulfur and selenium metabolism.

SUMMARY 3

NO 19-3
Theme Effect of iron and aluminum on growth of unicellular eukaryote Euglena gracilis Z
Reporter Chie Higashio(1), Masahiro Kohno(2), Tetsuya Suzuki(1)
Position (1) Graduate School of Fisheries Science, Hokkaido University
(2) Department of Environmental Systems Engineering, Kochi University of Technology
Volume The 19th Symposium on Trace Nutrients Research (2002)
P P.19-22
Summary Iron (Fe), an important essential trace element, causes oxidative stress in excess. Aluminum (Al), one of the most abundant elements in nature, also impairs plant growth. Al is recently suspected to cause degenerative nerve diseases in mammals. Al has been reported to enhance Fe-induced oxidative injuries in mammals. The present study was undertaken to assess whether similar adverse effect would be observed in the unicellular algae and protist, Euglena gracilis Z. The effect of single or combined exposure of Fe and Al from 0 to 5.0 mM on cell growth was examined. In comparison to the growth of E. gracilis in the Koren-Hutner medium [KH] containing 0.16 mM Fe2+ as the control, that in the KH without Fe was ca 25% less than the control. Addition of Fe2+ from 0.31 to 5.0 mM inhibited the cell growth dose dependently. Meanwhile, single addition of Al3+ from 0 to 5.0 mM also suppressed the growth above 0.16 mM, however, it was not dose dependent. Moreover, complex addition of Al3+ and Fe2+ from 0.16 to 5.0 mM for each element increased suppression of the cell growth than Fe and alone. Possible reasons for growth suppression by Fe and Al are discussed .

SUMMARY 4

NO 19-4
Theme Comparative study on the growth inhibition and metabolism of sodium arsenite in Euglena gracilis strains Z and SMZ
Reporter Akiko Suzuki (1), Toshikazu Kaise(2), Masumi Watanabe(1) and Tetsuya Suzuki(1)
Position (1)Hokkaido University, Graduate School of Fisheries Sciences, Division of Life Sciences
(2) Tokyo University of Pharmacy and Life Sciences
Volume The 19th Symposium on Trace Nutrients Research(2002)
P P.23-26
Summary Animals and plants differently respond to inorganic arsenite. In the present study, the authors examined the toxicity of sodium arsenite on the growth of an algae Euglena gracilis Z and its achlorophyllous mutant SMZ strains. The metabolism of sodium arsenite in Z and SMZ strains was also investigated by HPLC/ICP-MS. Comparing cell growth, Z strain was retarded under 0.25 to 0.5 mM, while the growth of SMZ retarded above 1mM indicating difference of cellular response between photosynthetic strain and non-photosynthetic strain. HPLC/ICP-MS analysis identified methyl arsenic acid, dimethyl arsenic acid, and trimethylarsine oxide in both the strains suggesting similar metabolic pathway in Euglena gracilis as reported in higher organisms.

SUMMARY 5

NO 19-5
Theme Arsenic Metabolites Excreted into the Human Urine after Hijiki Intake
Reporter Masayuki Katayama(1), Yohko Sugawa-Katayama(2), Chie Sakiyama(2), Yukie Kouya(2), Chiduru Furukawa(2) and Ken'ichi Hanaoka(3)
Position (1)Osaka Prefecture University
(2)Department of Human Health Science, Graduate School of Human Environment Sciences, Fukuoka Women's University
(3)Department of Food Science and Technology, National Fisheries University
Volume The 19th Symposium on Trace Nutrients Research(2002)
P P.27-33
Summary We intended to investigate effects of Hijiki intake on biochemical modification of the arsenic ingested by the human body. The 24 hour-urine was collected either before or after starting the Hijiki-diet, and urinary arsenic components were analyzed with an HPLC/ICP-MS instrument. Some differences in the urinary arsenic components were observed between before and after starting the Hijiki diet, but the differences were not the same in each individual, probably owing to different physiological or biochemical conditions.
Keywords: Arsenic metabolism, Hizikia fusiforme Okam., Human urine, Arsenite, HPLC/ICP-MS analysis, Neutron activation analysis, Methylarsonic acid, Dimethylarsinic acid, Arsenobetaine.

SUMMARY 6

NO 19-6
Theme The reproductive toxicity of organotin on the mammalian species
Reporter Hirofumi T. Suzuki, Yasuko Otani, Chiharu Ono, Nao Murayama, Chikako Yamaguchi, Maiko Kuroda, Rieko Oba, Yasuaki Arakawa
Position Department of Hygiene & Preventive Medicine, Faculty of Health Science, The University of Shizuoka
Volume The 19th Symposium on Trace Nutrients Research(2002)
P P.35-38
Summary Oroganotin compounds have been widely used as antifouling paints for ships. However, once these compounds are released into the aquatic environment, they act as environmental hazards. One of the well-known effects of organotin compounds is the endocrine-disrupting activity on marine snails. Tributyltin chloride (TBTC) has been shown to induce imposex in female gastropods, producing male genitals to female ones. However, the effects of organotin compounds on the reproduction of mammal are largely unknown. Here we demonstrate the toxicity of TBTC on mammalian reproduction. Histopatholotical examination of testes of rats treated with TBTC showed the loss of interstitial tissue. Histochemical staining showed the accumulation of organotin in the interstitial tissue. As there are leydig cells responsible for the production of androgens in the interstitial tissue, we examined the concentration of testosterone in the blood. The concentration of testosterone was decreased significantly by the TBTC administration. These results indicate that TBTC can act as toxicant to the mammalian reproduction system by damaging the leydig cells in the interstitial tissue and by which disturbing the production of testosterone.

SUMMARY 7

NO 19-7
Theme Effects of low level tributyltin chloride on DNA in Euglena gracilis Z and SMZ strains
Reporter Tomo Kawamura(1), Takahiko Higasa(2), Mikio Fujioka (3), Mari Ohta(1), Masumi Watanabe(1) and Tetsuya Suzuki(1)
Position (1) Hokkaido University, Graduate School of Fisheries Science
(2) Kyoto University, Graduate School of Agricultural Science
(3) Kyoto University, Graduate School of Medical Science
Volume The 19th Symposium on Trace Nutrients Research(2002)
P P.39-42
Summary Tributyltin chloride (TBTCl) has been widely used as marine anti-fouling and caused serious toxicity to organisms. In this study, effects of low concentration TBTCl exposure to Euglena gracilis Z and SMZ, particularly, on cell growth and DNA strand were examined. The inhibition of cell growth for 3 days exposure to TBTCl was observed dose dependently from 1 to 4μM in both the strains. Comet assay showed DNA strand breaks at 1μM TBTCl exposure in both the strains. These results suggest that micro-molar TBTCl exposure inhibited cell growth and induced DNA breaks to E. gracilis Z and SMZ. Key words: Tributyltin chloride (TBTCl), comet assay, DNA strand breaks

SUMMARY 8

NO 19-8
Theme Characteristics of Zinc-rich Fraction Prepared from Oyster
Reporter Munehiro Yoshida(1), Noboru Hirata(1), Sachiko Kitani(1), Yoshikazu Matsuda(2)
Position (1) Laboratory of Food and Nutritional Sciences, Faculty of Engineering, Kansai University
(2) Japan Clinic Co., Kyoto, Japan
Volume The 19th Symposium on Trace Nutrients Research(2002)
P P.43-46
Summary We have already obtained zinc-rich fraction (ZRF) from boiled oyster by extraction with 0.1 N HCl followed by neutralization and heating (patent No. 3267962). In the present study, to evaluate a nutritional availability of the ZRF, several characteristics of the ZRF were investigated. An insolubilization of zinc in the 0.1 N HCl-extract of boiled oyster was promoted with an elevation of pH. In particular, a rapid insolubilization was observed at pH 6.5 to 7.5 independently to the insolubilization of ninhydrin positive substances. This indicates that zinc recovered into the ZRF by the neutralization is mostly present as zinc hydroxide. Zinc in the ZRF was more soluble in solutions containing citrate or casamino acids than zinc as a form of zinc carbonate. Zinc in the ZRF could be solubilized by digest of protein or organic acids in a digestive tract; intestinal absorption of zinc in the ZRF may be higher than that of zinc carbonate

SUMMARY 9

NO 19-9
Theme Suppression of UVA-induced skin damage by topical application of zinc(II) chloride -In vivo real-time chemiluminescent assay-
Reporter Hiroyuki Yasui and Hiromu Sakurai
Position Department of Analytical and Bioinorganic Chemistry, Kyoto Pharmaceutical University
Volume The 19th Symposium on Trace Nutrients Research(2002)
P P.47-49
Summary Recent increase of ultraviolet (UV) lights owing to the increase of ozone hole may induce enhancement of the skin damage in all living systems on the earth. The harmful effects of UV exposure on the skin are supposed to associate with the generation of reactive oxygen species (ROS), however, no direct proof of ROS production in the skin under UV exposure was established. Recently, we reported first the in vivo detection and imaging of ROS generation in the skin of live hairless animals following UVA exposure, using both the sensitive chemiluminescent probe (CLA) and the ultralow-light imaging apparatus with a CCD camera. It was proposed that ·O2- is formed spontaneously and 1O2 is generated by UVA exposure in the skin of live mice. The method was applied to find suppressive agents against skin damage by UVA exposure. The topical application of zinc(II) chloride suppressed the ROS generation induced by UVA exposure even after the removal of Zn(II) from the skin. The mechanism for suppression of skin damage by Zn(II) is now under investigation.

SUMMARY 10

NO 19-10
Theme Influence of NaFeEDTA and ferrous sulfate on the absorption of trace elements in rats everted intestinal segments
Reporter Kaori Igarashi(1,2), Yukiko Nakanishi(1), Rieko Hirunuma(2), Shuichi Emoto(2), Shuichi Kimura(1)
Position (1) Graduate School of Human Life Sciences, Showa Womenfs University
(2) RIKEN
Volume The 19th Symposium on Trace Nutrients Research(2002)
P P.51-53
Summary The high incidence of iron deficiency in developing countries is attributed to the bioavailability of iron derived from staple food. Iron fortification has been implemented to improve iron deficiency in many countries. Sodium iron ethylenediaminetetraacetic acid (NaFeEDTA), a metal chelator, is one of the food additives for iron fortification. On the other hand, it is possible that EDTA may bind to metals and influence their absorption because of its chelating property. Thus, to investigate the effects of NaFeEDTA and ferrous sulfate on the absorption of trace elements, we determined the uptake of trace elements in rats everted intestinal segments. The result suggests that NaFeEDTA is increased the intestinal absorption of iron, zinc and cobalt, and less affected by tannic acid on the absorption of these elements

SUMMARY 11

NO 19-11
Theme Preparation and characterization of antibody against glycyl-L-histidyl-L-lysine-copper (II) complex
Reporter Takaji Sato, Tomoko Haraguchi, Yoshihiro Saito and Masahiko Chikuma
Position Osaka University of Pharmaceutical Sciences
Volume The 19th Symposium on Trace Nutrients Research(2002)
P P.55-58
Summary Antiserum against gly-L-his-L-lys (GHK) -Cu2+ complex has been generated using BSA-GHK-Cu2+ conjugate as an immunogen, and an EIA for the determination of GHK-Cu2+ has been developed. The standard curve allows the determination of 8x10-7 to 1x10-5 of GHK-Cu2+. The EIA method was applied to the determination of GHK-Cu2+ spiked in rat plasma. Recoveries were satisfactory from o-phenanthroline treated rat plasma whereas they were low from untreated rat plasma. The antiserum can bind to not only GHK-Cu2+ but also GHK, though the affinity is higher for the former than for the latter

SUMMARY 12

NO 19-12
Theme Dietary Intakes of Folate In Young Women
Reporter Kazu Suzuki(1), Yuuko Higasine(2), Yosiko Itou(3), Yukiko Yamada(1), Sakiyo Koseki(1),Toyoko Okuda(4)
Position (1)Seibo Jogakuin Junior College
(2)Osaka Shoin Women's College
(3)Osaka Aoyama Juniror College
(4)Osaka Kyoiku University
Volume The 19th Symposium on Trace Nutrients Research(2002)
P P.59-66
Summary Folate deficiency has recently drawn attention as a risk factor that causes fetal malformation. We conducted a dietary survey using a measuring method on female students to investigate the state of nutrient intake, and folate intake in particular. The female students had a low energy intake of 1,550±450 kcal, which accounted for 86% of the dietary energy allowance for women in their twenties. The female students' intakes of many vitamins and minerals were also much lower than the respective dietary allowances. Their intakes of protein and lipid accounted for 97% and 114% of the dietary allowances, respectively. The rates of meeting the intake targets classified by food group for men and women in their twenties were low for many food groups. However, the mean folate intake was 223±105 g, accounting for 112% of the dietary folate allowance in women in their twenties. This finding indicated that a dietary folate allowance of 200μg for women in their twenties could be consumed from the ordinary diet practically taken by the female students.
The former Ministry of Health and Welfare recommended that pregnant women take 400μg folate from meals and 400μg from nutrition supplementary food during before one month and the third month of pregnancy to reduce the risk of developing fetal neural tube defects. It has been reported, however, that few women in the fertile age take nutrition supplementary food. Therefore, we analyzed the food dietary constitution that allows folate intake of 400μg or 800μg from diet. It was demonstrated that consumption of 200 g of green vegetables and 200 g of other vegetables allowed folate intake of 400μg, and that consumption of 450 g of green vegetables and 200 g of other vegetables with green tea as something to drink allowed a folate intake of 800μg just from the diet.

SUMMARY 13

NO 19-13
Theme Gender differences in Vitamin K of rat plasma and brain
Reporter Atsuko Takeda(1,2),Hidekazu Hiraike (1,3),Naoki Hatsuda(3), Natsumi Ueno(1), Masayo Imanishi(1), Ryuji Takeda(1), Takahisa Takeda(1,3), Hiroshi Tamai(2), Mieko Kimura(1,3)
Position (1)Takeda Research Institute of Life Science
(2)Osaka medical college
(3)Graduate School of Medicine, Kyoto University
Volume The 19th Symposium on Trace Nutrients Research(2002)
P P.67-70
Summary It is a well-known fact that neonatal and infantile vitamin K deficiencies cause melena neonatorum and intracranial haemorrhagic disorders. These disorders occur more frequently in breast-fed babies than in bottle-fed babies. It is thought that these disorders are caused by vitamin K deficient diet of their mothers. But there are still many unclear parts about the role of vitamin K. In this study, vitamin K1 and MK-4 concentrations in plasma and brain of rat were measured and compared with difference of gender. Vitamin K1 and MK-4 concentrations were measured by the method using two columns switching HPLC system. In plasma of control rat, the concentration of MK-4 in female rat (0.138±0.027ng/ml) was significantly high compared with male rat (0.020±0.010ng/ml). But there was no significant difference between the concentrations of K1 in female rat (0.076±0.024ng/ml) and of male rat (0.180±0.057ng/ml). In plasma of minko rat, the concentration of MK-4 in female rat (0.133±0.024ng/ml) was significantly high compared with male rat (0.075±0.008ng/ml), and the concentration of K1 in female rat (0.098±0.021ng/ml) was significantly high compared with male rat (0.045±0.008ng/ml). In brain of control rat, the concentration of MK-4 in female rat (25.28±3.69ng/g) was significantly high compared with male rat (11.36±1.02ng/g). But there was no significant difference between the concentrations of K1 in female rat (0.483±0.014ng/g) and of male rat (0.392±0.048ng/g). In brain of minko rat, the concentration of MK-4 in female rat (26.43±0.86ng/ml) was significantly high compared with male rat (14.76±0.40ng/g), and the concentration of K1 in female rat (0.395±0.024ng/ml) was significantly high compared with male rat (0.329±0.017ng/g). These results suggest that MK-4 may be the predominant form of vitamin K and concentrations in rats are affected by gender. Gender differences must be taken into account in establishing the nutrient requirement for vitamin K.

SUMMARY 14

NO 19-14
Theme Change of free amino acid and mineral contents during the maturation of Murasakizukin, immature black soybean.
Reporter Onkoo Rhee(1), Takeshi Kawai(2), Hideki Tsuboi(3), Masao Wada(1), Kenji Sato(1), Takahisa Minamide(1), Kimiko Ohtani(1)
Position (1)Department of Food Sciences and Nutritional Health, Kyoto Prefectural University
(2) Kyoto Prefectural Agricultural Research Institute
(3)Hitachi Science Systems. Ltd.
Volume The 19th Symposium on Trace Nutrients Research (2002)
P P.71-75
Summary The change of free-amino acid and mineral contents during the maturation of Murasakizukin, immature black soybean (Glycine Max Merrill,Forma Kuromame Makino) were examined. The contents of free-amino acids, especially asparagine, γ-Aminobutyric acid(GABA), glutamic acid and alanine, were high in the early stage of maturation, but they decreased according with to maturation. The GABA content of the early stage of Murasakizukin was 15 times high, comparing with that of yellow soybean. Mineral contents were increased according with to maturation. Especially magnesium content (mean content of all stages of maturation) was 4 times high in Murasakizukin compared with that of yellow soybean. In the view points as functional foods, the best season of Murasakizukin were thought to be the early stage of maturation.

SUMMARY 15

NO 19-15
Theme Antioxidant action of xanthurenic acid : Inhibition of lipid peroxidation and protection for NADP-isocitrate dehydrogenase
Reporter Keiko Murakami, Toshiko Makino, Miyako Haneda and Masataka Yoshino
Position Department of Biochemistry, Aichi Medical University School of Medicine
Volume The 19th Symposium on Trace Nutrients Research (2002)
P P.77-82
Summary Vitamin B6 deficiency increases the lipid peroxidation and the synthesis of xanthurenic acid from tryptophan. Antioxidant properties of xanthurenic acid were examined in relation to the coordination of transition metals. Xanthurenic acid inhibited the formation of thiobarbituric acid-reactive substances as a marker of iron-mediated lipid peroxidation, and copper-dependent oxidation of low density lipoprotein. NADP-isocitrate dehydrogenase and malic enzyme, principal NADPH-generating enzymes for antioxidant defense system, was inactivated by reduced iron, and xanthurenic acid protected the enzyme from this inactivation. Xanthurenic acid may participate in the enhanced regeneration of reduced glutathione by stimulating NADPH supply. Xanthurenic acid further enhanced the autooxidation of Fe2+ ion. Other tryptophan metabolites such as kynurenic acid and quinaldic acid did not inhibit the lipid peroxidation and the inactivation of NADP-isocitrate dehydrogenase, and showed little or no effect on the Fe2+ autooxidation. Antioxidant properties of xanthurenic acid are related to the metal-chelating activity and probably to the enhanced oxidation of reduced transition metals as prooxidant.

SUMMARY 16

NO 19-16
Theme Zinc-containing Thermostable Alcohol Dehydrogenase with Low Substrate Specificity, and Aldehyde Dehydrogenase from Psychrophile, Cytophaga sp. KUC-1: Characterization and Application to Alcohol Determination
Reporter Takayuki Kazuoka, Ikuo Muraoka, Yoshihiro Yoshida, Noriyuki Kanzawa, Noriaki Arakawa, Tadao Oikawa and Kenji Soda
Position Faculty of Engineering, Kansai University
Volume The 19th Symposium on Trace Nutrients Research(2002)
P P.83-86
Summary The over expression systems of Cytophaga alcohol dehydrogenase and aldehyde dehydrogenase in Escherichia coli were constructed, and both enzymes were purified to homogeneity. The alcohol dehydrogenase contained 2 g-atoms of zinc per subunit, but the aldehyde dehydrogenase was independent of any metals. Both enzymes showed low substrate specificities. They showed thermo stability, although were produced by a psychrophilic bacterium: the half-life times of Cytophaga alcohol dehydrogenase and aldehyde dehydrogenase were over 200 and 65 min at 50oC, respectively. The Km value of Cytophaga alcohol dehydrogenase is 40-50 times lower than that of the Saccharomyces enzyme, and the kcat/Km value of the Cytophaga enzyme is much higher than that of the Saccharomyces enzyme. Ethanol was determined with about 175 times less Cytophaga alcohol dehydrogenase than the Saccharomyces enzyme. The addition of Cytophaga aldehyde dehydrogenase led to an increase in sensibility.

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