Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 67 , Issue 6
Showing 1-39 articles out of 39 articles from the selected issue
Analytical Chemistry Regular Papers
  • Jae Han SHIM, Mi Hyun LEE, Mi Ra KIM, Chang Joo LEE, In Seon KIM
    2003 Volume 67 Issue 6 Pages 1342-1348
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      Simultaneous detection of the fluoroquinolone antibiotics ciprofloxacin, enrofloxacin, ofloxacin, and norfloxacin in eggs by a combination of supercritical fluid extraction (SFE) and high pressure liquid chromatography (HPLC) was studied. Lipid matrices that have been considered to result in poor extraction and isolation of fluoroquinolones in eggs were removed first by SFE with supercritical CO2 alone, and then the fluoroquinolones were extracted by SFE with supercritical CO2 containing 20% (v/v) methanol for HPLC analysis. A time-course study of the extraction of lipid matrices of eggs suggested that the SFE method successfully removed the matrices within 20 min. When the fluoroquinolones added to control eggs were extracted by SFE, the extraction efficiency was similar to that by the solvent extraction method, giving the recovery percentages from 83 to 96% in a 40 min-extraction time. The fluoroquinolones extracted from eggs by SFE were analyzed simultaneously by HPLC equipped with a fluorescence detector with detection sensitivity at about 10 ppb for the detection limit. The standard calibration profiles of fluoroquinolones showed linear responses to HPLC, showing more than 0.995 for the mean r2 value. This is the first report of the simultaneous measurement of fluoroquinolones in eggs by a combination of SFE and HPLC. Using the SFE method allowed us to avoid extensive sample preparation such as solvent extraction and chromatographic cleanup that are basically required in extraction of fluoroquinolones.
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  • Kosuke NISHI, Mikio TAKAI, Kosuke MORIMUNE, Hideo OHKAWA
    2003 Volume 67 Issue 6 Pages 1358-1367
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      Four anti-bisphenol A monoclonal antibodies (mabs) were obtained and each characterized by an enzyme-linked immunosorbent assay (ELISA). Among these mabs, BBA-2187 was the most reactive towards bisphenol A. The quantitation limit of the ELISA assay for bisphenol A was 0.13 ng/ml, which is more sensitive than the other immunoassays reported. Then, the cDNA clones encoding variable heavy and variable light chains of these four mabs were isolated, and used for construction of four single-chain Fv (scFv) antibody genes, which were expressed in Escherichia coli cells. The reactivity of four scFv antibodies towards bisphenol A in ELISA was comparable to those of the parent mabs. The most sensitive assay was achieved with BBA-2187scFv. Its cross-reactivity to the related compounds was similar to that of the parent mab. Based on the reactivity of heterologous combinations of VH and VL fragments, it was found that the unique structure of the framework region 2 in the VL of BBA-2187 appeared to be important for specific assembly together with the VH.
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Organic Chemistry Regular Papers
  • Mitsuru ITO, Hideshi OKUI, Harumi NAKAGAWA, Shigeru MIO, Ayako KINOSHI ...
    2003 Volume 67 Issue 6 Pages 1230-1238
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      A series of 5-spirocyclohexyl-3-(2,6-dimethylphenyl)-1,5-dihydro-2H-pyrrol-2-one derivatives (3) with various substituents on the spirocyclohexyl ring was synthesized and evaluated for its insecticidal activity against the aphid, Myzus persicae. Substituents at the 1- and 4-positions of the dihydropyrrole ring were also varied to optimize the activity. An investigation of the structure-activity relationship revealed that methoxy, alkoxyalkoxy, ethylenedioxy and methoxyimino groups were favorable as substituents at the 4-position of the spirocyclohexyl ring. The activity was optimized by the respective substitution of a methoxy or methoxymethoxy moiety and cyclopropylcarbonyloxy group at the 1- and 4-positions of the dihydropyrrole ring.
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  • Shigeki JIN, Midori YOSHIDA, Takashi NAKAJIMA, Akio MURAI
    2003 Volume 67 Issue 6 Pages 1245-1249
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      It was found that the content of antifungal compounds p-coumaroylagmatine [1-(trans-4′-hydroxycinnamoylamino)-4-guanidinobutane] and p-coumaroyl-3-hydroxyagmatine [1-(trans-4′-hydroxycinnamoylamino)-3-hydroxy-4-guanidinobutane] in the crown of winter wheat (Triticum aestivum L. cv Chihokukomugi) significantly increased under snow cover. This finding suggests that the accumulation of these hydroxycinnamic acid amides was caused by winter stress and related to protecting the plant against snow mold under snow cover.
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Organic Chemistry Notes
Biochemistry & Molecular Biology Regular Papers
  • Yuuki ASAI, Kazuya YAMADA, Toyoaki WATANABE, Vincent W. KENG, Tamio NO ...
    2003 Volume 67 Issue 6 Pages 1272-1277
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      M2-type pyruvate kinase (M2-PK) mRNA is produced from the PKM gene by an alternative RNA splicing in adipocytes. We found that insulin increased the level of M2-PK mRNA in 3T3-L1 adipocytes in both time- and dose-dependent manners. This induction did not require the presence of glucose or glucosamine in the medium. The insulin effect was blocked by pharmacological inhibitors of insulin signaling pathways such as wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3K), and PD98059, an inhibitor of mitogen-activated protein kinase (MAPK) kinase. A stable reporter expression assay showed that the promoter activity of an about 2.2-kb 5′-flanking region of the rat PKM gene was stimulated by insulin, but the extents of these stimulations were lower than those of the mRNA stimulation. Thus, we suggest that insulin increases the level of M2-PK mRNA in adipocytes by acting at transcriptional and post-transcriptional levels through signaling pathways involving both PI3K and MAPK kinase.
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  • Daisuke YASOKAWA, Takeshi SHIMIZU, Ryoji NAKAGAWA, Takayuki IKEDA, Koj ...
    2003 Volume 67 Issue 6 Pages 1319-1326
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      From a Corticium rolfsii cDNA library, a clone homologous to other fungal cellobiohydrolase (CBH1) genes was isolated using the polymerase chain reaction. In the nucleotide sequence, one 1.6 kb long open reading frame coding for a polypeptide of 530 amino acid residues was detected which showed 64% identity with CBH1 of Phanerochaete chrysosporium. With expression of the 1.8 kb cDNA using the Aspergillus oryzae expression system, we detected microcrystalline cellulose (Avicel) hydrolyzing activity in the culture supernatant. The secreted protein, accompanied by the activity, was 89 kDa by SDS-polyacrylamide gel electrophoresis.
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  • Teruhiko IDE, Sang-Ho BAIK, Takao MATSUBA, Shigeaki HARAYAMA
    2003 Volume 67 Issue 6 Pages 1335-1341
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      The four peptides interacting with H7 flagellin of Escherichia coli were selected from a phage display library. The library was selected four times, and the interacting phage peptides were competitively eluted with H7 flagellin. An enzyme-linked immunosorbent assay (ELISA) showed that these peptides were reactive with the H7 flagellin in a dose-dependent manner. Among them, a D1 phage clone showed the highest binding affinity to the H7 flagellin. We synthesized the D1 peptide (LHIHRPTLSIQG) corresponding to the peptide-encoding region of the D1 phage clone. The synthetic peptide showed micro-molar affinity (EC50 value=1.9 μM) for the H7 flagellin. Furthermore, this D1 peptide interacted more specifically with the H7 flagellin than with the other flagellins (H1, H5, H12, or H23) of E. coli. In situ hybridization clearly showed that the peptide only detected those cells harboring the H7 flagellin gene (fliC). The peptide may specifically bind to the H7 flagellin on the cell surface. These results suggest that the phage-display technique could be used as a tool for identifying peptides as an alternative to using a ligand as a diagnostic reagent in food products or in clinical testing.
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  • Hiroto SHINOMIYA, Kozo NAGAI, Hajime HIRATA, Naoto KOBAYASHI, Hitoshi ...
    2003 Volume 67 Issue 6 Pages 1368-1375
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      We previously identified a 65-kDa protein (p65) that was phosphorylated in activated macrophages. It has turned out to be a murine homologue of human L-plastin, which was identified as a novel protein in human cancer cells. p65/L-plastin is characterized by a series of Ca2+-, calmodulin-, and actin-binding domains, and is thought to play a crucial role in leukocytes and cancer cells. We have expressed a recombinant (r) p65/L-plastin in Escherichia coli that binds to β-actin and prepared high-titer antibodies using large amounts of the protein as immunogen. Anti-rp65/L-plastin antibodies recognize native p65/L-plastin as well as rp65/L-plastin and have enabled us to detect the fine structures of intracellular p65/L-plastin, and it was found that its localization was extensively changed by stimulation with bacterial components. We further developed an enzyme-linked immunosorbent assay system and a flow cytometry method using these reagents, which made it possible to measure antibodies, including autoantibodies, against p65/L-plastin and to evaluate the maturation-dependent expression of the protein in leukocytes.
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  • Yoko ITO, Munehiko ASAYAMA, Makoto SHIRAI
    2003 Volume 67 Issue 6 Pages 1382-1390
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      We characterized the function of the −35 hexamer in the promoter and an element just upstream, UPE, in the expression in a unicellular cyanobacterium, Microcystis aeruginosa K-81, of the light-responsive gene psbA2, which encodes a reaction center key protein for photosynthesis. A series of mutants with mutations at the −35 hexamer (−35 to −30) and a novel conserved upstream element (UPE: −45 to −36, +1 referring to the transcription start point) were constructed. Expression of the mutants was examined in vivo and in vitro by analyses using a β-galactosidase assay, primer extension, and a DNA-mobility shift assay with RNA polymerases. Results indicated that the −35 hexamer and its proximal UPE act as effective cis-elements for the light-responsive and/or basal transcription, respectively. A model of the 5′-upstream region with cis- and possible trans-acting factors is presented for the psbA regulatory system.
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Biochemistry & Molecular Biology Notes
Food & Nutrition Science Regular Papers
  • Masaki MIYAKE, Norie ARAI, Shimpei USHIO, Kanso IWAKI, Masao IKEDA, Ma ...
    2003 Volume 67 Issue 6 Pages 1199-1205
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      A number of agents have been reported to influence osteoblastic differentiation and to prevent and treat bone loss. We found that kaempferol, a flavonoid identified in extracts of the medicinal plant, Polygonum tinctorium. Lour, had stimulatory effects on the differentiation and mineralization of the murine pre-osteoblastic cell line, MC3T3-E1. After enhancing the alkaline phosphatase activity, significant augmentation of calcification by kaempferol was observed between concentrations of 10 and 20 μM, without any marked effect on cell proliferation. When kaempferol was combined with ipriflavone, which is clinically applied to treat bone loss, calcification was synergistically augmented, suggesting that these two flavonoids may have different mechanisms of action.
      These results suggest that kaempferol may be a promising agent for the prevention or treatment of bone loss, especially when combined with ipriflavone.
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  • Naohiko INOUE, Kyoko KURODA, Akio SUGIMOTO, Takami KAKUDA, Tohru FUSHI ...
    2003 Volume 67 Issue 6 Pages 1206-1214
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      The effect of jasmine tea odor on the autonomic nervous system was investigated by a power spectral analysis of the heart rate variability. We assigned eight volunteers to two groups with either a predilection for or antipathy toward the jasmine tea odor. We tested both high- and low-intensity jasmine tea odors. The low-intensity odor was produced by diluting 20-fold the jasmine tea used for the high-intensity odor test. The low-intensity odor produced an increase in parasympathetic nervous activity in both the predilection and antipathy groups. The high-intensity odor produced an increase in parasympathetic nervous activity in the predilection group, but an increase in sympathetic nervous activity in the antipathy group. The odor of Chinese green tea, a basic ingredient of jasmine tea, produced no effects similar to those of the jasmine tea odor. These results suggest that the jasmine tea odor activated the parasympathetic nerve, whereas the higher-intensity odor activated the sympathetic nerve in those subjects who disliked the odor.
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  • Gow-Chin YEN, Pin-Der DUH, Hui-Ling TSAI, Shih-Li HUANG
    2003 Volume 67 Issue 6 Pages 1215-1222
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      The pro-oxidative properties of the four flavonoids, quercetin, morin, naringenin and hesperetin, in human lymphocyte system were investigated. Naringenin and hesperetin accelerated the oxidation of deoxyribose induced by Fe3+/H2O2 in a concentration range of 0–200 μM, but quercetin and morin decreased it when the concentration was greater than 100 μM. The generation of hydrogen peroxide and the superoxide anion and the production of TBARS in lymphocytes were increased with increasing concentration of a flavonoid. Cell membrane protein thiols of the lymphocytes decreased when treated with the four flavonoids. Quercetin and hesperetin had no significant effect (p>0.05) on the activity of glutathione reductase, but morin and naringenin could inhibit the activity of the enzyme at a concentration of 200 μM, when compared to the control group. The glutathione S-transferase activity was slightly decreased by treatment with each of the four flavonoids only at a concentration of 200 μM. Therefore, the DNA damage in lymphocytes induced by the flavonoids in the model system might have been due to their stimulation of oxidative stress in the lymphocytes, which resulted in the decrease of cell membrane protein thiols, increase of lipid peroxidation in cell membrane and in the influence of the antioxidative enzyme activities.
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  • Masao GOTO, Satoshi HACHIMURA, Akio AMETANI, Takehito SATO, Yoshihiro ...
    2003 Volume 67 Issue 6 Pages 1223-1229
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      To study how intestinal intraepithelial lymphocytes (IEL) are affected by orally ingested antigen, the phenotypes and responses of the IEL in mice expressing a transgenic T cell receptor αβ (TCR αβ) specific for ovalbumin (OVA) were analyzed after feeding OVA. In the OVA-fed mice, the abundance of αβ-IEL as a proportion of the total IEL population increased and the frequency of CD4+ cells increased within the TCR αβ+ IEL population. CD4+ IEL from OVA-fed transgenic mice proliferated in vitro more markedly in response to antigen stimulation than IEL from mice fed the control diet. These results indicate that antigen-specific proliferation of CD4+ IEL was amplified as a result of oral administration of antigen.
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  • Shoko KOBAYASHI, Jun WATANABE, Eri FUKUSHI, Jun KAWABATA, Mitsutoshi N ...
    2003 Volume 67 Issue 6 Pages 1250-1257
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      Some spices showed high inhibitory activity against ovalbumin permeation through Caco-2 cell monolayers. Pimentol from allspice, rosmarinic acid and luteolin-7-O-β-glucuronide from thyme, quercetin-3-O-β-glucuronide from coriander and rutin from tarragon were identified as the active principles. A structure-activity relationship study among the active isolates and their related compounds indicated that the presence of a catechol structure played an important role in the inhibitory activity of each compound.
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  • Yasuhiko SHIMADA, Akihiro YAMAKAWA, Tatsuya MORITA, Kimio SUGIYAMA
    2003 Volume 67 Issue 6 Pages 1258-1266
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      Eritadenine, a hypocholesterolemic factor of Lentinus edodes mushroom, has a wide range of effects on lipid metabolism such as an increase in the liver microsomal phosphatidylethanolamine (PE) concentration, a decrease in the liver microsomal Δ6-desaturase activity, and an alteration of the fatty acid and molecular species profile of liver and plasma lipids. In this study, the time-dependent effects of dietary eritadenine on several variables concerning lipid metabolism were investigated in rats to clarify the sequence of metabolic changes caused by eritadenine, with special interest in the association of the liver microsomal phospholipid profile and the activity of Δ6-desaturase. The effect of dietary eritadenine on the abundance of mRNA for Δ6-desaturase was also investigated. When the time required for a half-change of variables was estimated during the first 5 days after the change from the control diet to the eritadenine-supplemented (50 mg/kg) diet, the change rates of the variables were fastest in the following order: alteration of the liver microsomal phospholipid profile>decrease in liver microsomal Δ6-desaturase activity>alteration of the fatty acid and molecular species profiles of microsomal and plasma phosphatidylcholine (PC)>decrease in the plasma cholesterol concentration. There was a significant correlation between the Δ6-desaturase activity and liver microsomal PE concentration, but not PC concentration, or the proportion of PC and PE or the PC/PE ratio. The suppression of Δ6-desaturase activity by dietary eritadenine was accompanied by a significant reduction in the abundance of mRNA for the enzyme. These results suggest that dietary eritadenine might suppress the activity of liver microsomal Δ6-desaturase by altering the microsomal phospholipid profile, as represented by an increase in PE concentration, and that the effect of eritadenine is mediated by the regulation of gene expression.
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  • SUPRIYADI , Masayuki SUZUKI, Shuiqin WU, Naomi TOMITA, Akira FUJITA, N ...
    2003 Volume 67 Issue 6 Pages 1267-1271
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      The methyl esters of carboxylic acids are characteristic olfactory volatile compounds for the sweet aroma of snake fruit, (Salacca edulis, Reinw) cv. Pondoh. Although methanol was not detected as a volatile constituent, the crude enzymes showed activity to synthesize the methyl esters in the presence of acyl-CoA and methanol. Therefore, the biosynthetic origin of methanol was investigated, resulting in the detection of pectin methyl transferase activity in the flesh. This pectin methyl transferase activity increased during fruit maturation, in parallel with the level of methanol originating from hand-squeezed juice and with the methyl esters extracted from flesh of the fruit. Based on these results, the origin of methanol was confirmed to be the methyl esters of pectins. The crude enzyme also catalyzed the formation of methyl hexanoate, one of the esters of the fruit, in the presence of methyl pectins and hexanoyl-CoA that were used as precursors for a model reaction.
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  • Megumi KUBA, Kumi TANAKA, Shinkichi TAWATA, Yasuhito TAKEDA, Masaaki Y ...
    2003 Volume 67 Issue 6 Pages 1278-1283
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      Angiotensin I-converting enzyme (ACE) inhibitory activity was observed in a tofuyo (fermented soybean food) extract with an IC50 value of 1.77 mg/ml. Two ACE inhibitors were isolated to homogeneity from the extract by adsorption and gel filtration column chromatography, and by reverse-phase high-performance liquid chromatography (HPLC). The purified substances reacted with 2,4,6-trinitrobenzensulfonic acid sodium salt. The amino acid sequences of these inhibitors determined by Edman degradation were Ile-Phe-Leu (IC50, 44.8 μM) and Trp-Leu (IC50, 29.9 μM). The Ile-Phe-Leu sequence is found in the α- and β-subunits of β-conglycinin, while the Trp-Leu sequence is in the B-, B1A- and BX-subunits of glycinin from soybean. Both of the peptides are non-competitive inhibitors. The inhibitory activity of Trp-Leu was completely preserved after a treatment with pepsin, chymotrypsin or trypsin. Even after successive digestion by these gastrointestinal proteases, the activity remained at 29% of the original value.
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  • Ho-Jin HEO, Young-June PARK, Young-Min SUH, Soo-Jung CHOI, Mi-Jeong KI ...
    2003 Volume 67 Issue 6 Pages 1284-1291
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      We screened 50 Korean traditional natural plants to measure the activation effect on choline acetyltransferase and attenuation of scopolamine-induced amnesia. The methanolic extracts from Zizyphus jujuba among the tested 50 plants, showed the highest activatory effect (34.1%) on choline acetyltransferase in vitro. By sequential fractionation of Zizyphus jujuba, the active component was finally identified as cis-9-octadecenoamide (oleamide). After isolation, oleamide showed a 65% activation effect. Administration of oleamide (0.32%) to mice significantly reversed the scopolamine-induced memory and/or cognitive impairment in the passive avoidance test and Y-maze test. Injection of scopolamine to mice impaired performance on the passive avoidance test (31% decrease in step-through latency), and on the Y-maze test (16% decrease in alternation behavior). In contrast, mice treated with oleamide before scopolamine injection were protected from these changes (12–25% decrease in step-through latency; 1–10% decrease in alternation behavior). These results suggest that oleamide should be a useful chemo-preventive agent against Alzheimer's disease.
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  • Byung-Keun YANG, Jun-Bo PARK, Chi-Hyun SONG
    2003 Volume 67 Issue 6 Pages 1292-1298
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      The hypolipidemic effect of an exo-biopolymer produced from a submerged mycelial culture of Hericium erinaceus was investigated in dietary-induced hyperlipidemic rats. Hypolipidemic effects were proportionally increased with the increasing concentration of the exo-biopolymer for oral administration. The exo-biopolymer, at the dose of 200 mg/kg body weight, substantially reduced the plasma total cholesterol (32.9%), LDL cholesterol (45.4%), triglyceride (34.3%), phospholipid (18.9%), atherogenic index (58.7%), and hepatic HMG-CoA reductase activity (20.2%). It increased the plasma HDL cholesterol level (31.1%) as compared to the control group. The molecular mass of this exo-biopolymer measured by HPLC was under 40 kDa. Total sugar and protein contents were 91.2 and 8.8%, respectively. The sugar and amino acid compositions of the exo-biopolymer were analyzed in detail.
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  • Thanakorn WEANGSRIPANAVAL, Noriko NOMURA, Tatsuya MORIYAMA, Nobuo OHTA ...
    2003 Volume 67 Issue 6 Pages 1299-1304
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      A 45 kDa protein, which is recognized by IgE antibodies in sera of food-allergic patients, was purified and characterized as an allergenic protein from the tomato. The IgE-binding protein purified from tomato extract was found to be a glycoprotein with a molecular weight of approximately 45,000, an isoelectric point of 4.2, and no free N-terminal amino group. Furthermore, it was shown that the purified protein had peroxidase activity. From the amino acid sequence of a peptide fragment prepared by lysylendopeptidase digestion, the allergenic protein was identified to be the tomato suberization-associated anionic peroxidase 1 known as one of the pathogenesis-related proteins widely distributed in plants. These properties suggested the protein isolated from tomato to be a new allergenic protein in plant foodstuffs.
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  • Yoko SAKAI, Tetsuo MURAKAMI, Yukiko YAMAMOTO
    2003 Volume 67 Issue 6 Pages 1305-1311
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      This study was designed to show the effects of onion on blood pressure in NG-nitro-L-arginine methyl ester (L-NAME) induced-hypertensive rats and stroke prone spontaneously hypertensive rats (SHRSP) using dried onion at 5% in their diets. For the experiment with L-NAME induced-hypertensive rats, male 6-weeks-old Sprague-Dawley rats were given tap water containing L-NAME to deliver 50 mg/kg BW/day. In this experiment, we found distinct antihypertensive effects of onion on the L-NAME induced-hypertensive rats and the SHRSP. Dietary onion decreased the thiobarbituric acid reactive substances (TBARS) in plasma in these hypertensive rats. Also, onion increased the nitrate/nitrite (products of nitric oxide (NO)) excreted in urine and the NO synthase (NOS) activity in the kidneys in SHRSP. These results suggested that the increased NO caused by the greater NOS activity, and additionally by the increased saving of NO by the antioxidative activity of onion, was one of the cause of the antihypertensive effect of onion in SHRSP. In the L-NAME induced hypertensive rats, onion did not significantly block the inhibition of NOS activity by L-NAME, and decreased nitrate/nitrite excretion in urine was not restored. The mechanism of the antihypertensive effect of onion probably involves increased saving of NO by antioxidative activity of onion in L-NAME induced-hypertensive rats.
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  • Hideo SATSU, Tatsuya YOKOYAMA, Nobumasa OGAWA, Yoko FUJIWARA-HATANO, M ...
    2003 Volume 67 Issue 6 Pages 1312-1318
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      The effect of neuronal cells on the functional properties of intestinal epithelial cells was examined by using an in vitro coculture system. Two cell lines, Caco-2 and PC12, were respectively used as intestinal epithelial and enteric neuronal cell models. Coculture of differentiated Caco-2 cells with PC12 caused a significant decrease in the transepithelial electrical resistance (TER) value of the Caco-2 monolayer. The permeability to lucifer yellow (LY) was also significantly increased, suggesting that the tight junction (TJ) of the Caco-2 monolayers was modulated by coculturing with PC12. To identify the TJ-modulating factor presumably secreted from PC12, the effects of the major neurotransmitters on the TER value and LY transport were examined, but no influence was apparent. The TJ-modulating effect of PC12 was prevented by exposing PC12 to cycloheximide, suggesting that new protein synthesis in PC12 was necessary for this regulation.
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  • Shuji ADACHI, Hanaho IMAOKA, Yuri HASEGAWA, Ryuichi MATSUNO
    2003 Volume 67 Issue 6 Pages 1376-1381
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      Microcapsules of a water-in-oil-in-water (W/O/W) emulsion, which contained a hydrophilic substance, 1,3,6,8-pyrenetetrasulfonic acid tetrasodium salt (PTSA), in its inner aqueous phase, was prepared by hot-air-drying or freeze-drying the emulsion using a single-droplet-drying method. Pullulan, maltodextrin, or gum arabic was used as a wall material, and the oily phase was tricaprylin, oleic acid, olive oil, or a mixture of tricaprylin and olive oil. An encapsulation efficiency higher than 0.95 was reached except for the microcapsules prepared using gum arabic and oleic acid. The hot-air-dried microcapsules were generally more stable than the freeze-dried microcapsules at 37°C and various relative humidities. The stability was higher for the microcapsules with tricaprylin as the oily phase than for the microcapsules with oleic acid. The higher stability of the microcapsules with tricaprylin would be ascribed to the lower partition coefficient of PTSA to the oily phase. There was a tendency for the stability to be higher at lower relative humidity for both the hot-air- and freeze-dried microcapsules. The volumetric fraction of olive oil in its mixture with tricaprylin did not significantly affect either the encapsulation efficiency or the stability of the hot-air-dried microcapsules.
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Food & Nutrition Science Notes
Microbiology & Fermentation Technology Regular Papers
  • Jiraporn THANIYAVARN, Niran ROONGSAWANG, Takayuki KAMEYAMA, Mitsuru HA ...
    2003 Volume 67 Issue 6 Pages 1239-1244
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      A biosurfactant-producing strain, Bacillus licheniformis F2.2, was isolated from a fermented food in Thailand. The strain was capable of producing a new biosurfactant, BL1193, as well as two kinds of popular lipopeptide biosurfactants, plipastatin and surfactin. Mass spectrometry and FT-IR analysis indicated that BL1193 had a molecular mass of 1,193 Da with no peptide portion in the molecule. While plipastatin and surfactin were abundantly produced in a nutrient YPD medium, BL1193 was produced only in a synthetic DF medium containing no amino acids. According to an oil displacement activity test, the specific activity of BL1193 (6.53 kBS units/mg) is equivalent to that of surfactin (5.78–6.83 kBS units/mg).
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  • Tadashi WADA, Masao OHGUCHI, Yoshio IWAI
    2003 Volume 67 Issue 6 Pages 1327-1334
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      We found a bacterium that converts sucrose to a useful material, using about 6,000 samples of bacteria isolated from soil. This bacterium, Bacillus sp. 217C-11, was identified according to Bergey's manual, and produced a highly efficient enzyme that converted sucrose into inulin. So, the enzyme was purified to homogeneity through five chromatographic steps, to identify its enzymatic properties. The molecular mass of the enzyme was estimated to be 45,000, and this enzyme was a monomer protein (by SDS-PAGE). The optimum pH and temperature of this enzyme were 7–8 and 45–50°C, respectively. The enzyme reacted only with sucrose, but did not with other disaccharides, fructooligosaccharides and inulin. This paper will show that our enzyme is a novel one, which is different from the other well-known enzymes concerned in inulin production.
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  • Rika NOBE, Yoichi SAKAKIBARA, Nobuhiro FUKUDA, Naoto YOSHIDA, Kihachir ...
    2003 Volume 67 Issue 6 Pages 1349-1357
    Published: 2003
    Released: June 30, 2003
    JOURNALS FREE ACCESS
      At least three extracellular laminaran hydrolases which hydrolyzed laminaran (β-1,3:1,6-glucan) from Eisenia bicyclis were secreted in wheat bran solid medium by Trichoderma viride U-1. These three enzymes, lam AI, AII, and B, were purified to electrophoretic homogeneity. Their molecular masses were estimated to be 70.1, 70.4, and 45.0 kDa for lam AI, AII, and B, respectively, by SDS-PAGE. Whereas both lam AI and AII could hydrolyze laminarin from Laminaria digitata, lam AII showed higher activity against Laminaria laminarin rather than Eisenia laminaran. On the other hand, lam B preferentially hydrolyzed pustulan, a β-1,6-glucan. Laminarioligosaccharide was hydrolyzed by lam AI and AII but not B, whereas gentiooligosaccharide was hydrolyzed by only lam B. It showed that lam AI and AII were specific for β-1,3-linkages, but lam B was specific for β-1,6-linkages. These results indicated that T. viride U-1 has a multiple glucanolytic enzyme system.
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Microbiology & Fermentation Technology Notes
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