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To investigate the structure of the aflatoxin gene cluster in Aspergillus oryzae, 39 strains belonging to this species were examined for the existence of pksA, fas1A, aflR and vbs, and the results compared with those for ver-1 obtained previously. These five genes are involved in aflatoxin biosynthesis in Aspergillus parasiticus. The strains examined were categorized into three groups; group 1, having the five homologs; 2, having ver-1 and vbs; and 3, having vbs homologs. Long-PCR analysis of the regions between the five homologs in A. oryzae IFO 4135, coupled with Southern-hybridization analysis, shows that those homologs are clustered with the same arrangement as in A. parasiticus. These results suggest that directed deletions of the cluster occur in A. oryzae strains. The possible breakpoints of the deletions in the strains of group 2 and 3 were estimated.

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A mandarin-type citrus fruit, ponkan (Citrus reticulata), was processed by in-line, chopper pulper, and hand-press extractions to investigate the effect of extraction method on the concentrations of bioactive compounds in processed juice. Concentrations of polymethoxylated flavones (tangeretin, nobiletin, and sinensetin) and beta-cryptoxanthin in juice, and inhibitory activities against arachidonate cyclooxygenase and lipoxygenases of the juice extract were analyzed. The juice processed by hand-press extraction contained the largest amounts of nobiletin (3.56 mg/100 mL), tangeretin (4.10 mg/100 mL), and sinensetin (0.13 mg/100 mL). Concentrations of beta-cryptoxanthin were 0.66, 0.59, 0.55, and 0.50 mg/100 mL in chopper pulper, in-line (5/64 in.), in-line (8/64 in.) and hand-press juices, respectively. Both extracts of in-line juices showed greater inhibitory activity toward platelet 12-lipoxygenase than the others. The inhibitory effect of hand-press juice extract on platelet cyclooxygenase activity was remarkable among juice extracts. All juice extracts effectively inhibited polymorphonuclear 5-lipoxygenase activity at nearly the same rate.

The production of angiotensin I converting enzyme (ACE) inhibitory peptides by autolysis reactions from wheat milling byproducts was investigated. Milled whole grain, bran, shorts, and red dog acquired ACE inhibitory activity though water soaking treatment. Among the milled fractions, the preparation of shorts exhibited the strongest inhibitory activity (IC50 = 0.08 mg protein/mL) followed by that of bran, red dog, and whole grain in decreasing order. The production of ACE inhibitory peptides was almost completely inhibited by pepstatin A, indicating the contribution of aspartic proteases. The optimal pH for acquiring ACE inhibitory activity of the byproduct fraction (mixtures of bran and shorts) was 3.2. The level of inhibitory activity rose with increasing temperature up to 40 degrees C. The inhibitory activity reached a maximal level after a 12 h reaction time and maintained the same level up to 24 h at 40 degrees C, pH 3.2. From the hydrolysate of the byproduct fraction, six peptides were isolated by several steps of chromatography, and their amino acid sequences were Leu-Gln-Pro, Ile-Gln-Pro, Leu-Arg-Pro, Val-Tyr, Ile-Tyr, and Thr-Phe. Thus, wheat milling byproducts have the possibility to become an effective source for ACE inhibitory peptides.

The content of insoluble bound phenolic acids in pearled barley was determined by an analytical system consisting of alkaline hydrolysis extraction, high-performance liquid chromatographic separation and electrochemical detection. Insoluble bound phenolic acids in five pearled cultivars and fifteen breeding lines of barley comprised ferulic acid (4.3-34.2 mg/100 g dry matter), sinapic acid (0.025-0.445 mg/100 g), caffeic acid (0.002-0.016 mg/100 g). Soluble free polyphenols comprised procyanidins (12.2-80.3 mg/100 g), catechin (0.1-28.2 mg/100 g), and total pholyphenol comprised 152.4-324.0 mg-gallic acid equivalents/100 g. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity for the barley samples ranged from 403 to 1501 μmol-Trolox equivalents/100 g whereas those of oxygen radical absorbance capacity (ORAC) ranged from 1050 to 3816 μmol-Trolox equivalents/100 g. High correlation (0.980, p<0.01) was found between the DPPH and ORAC assays. Total polyphenol contents positively correlated with the DPPH (0.875, p<0.01) and ORAC (0.881, p<0.01) assays. The correlation coefficient between insoluble bound phenolic acids and total polyphenol contents was higher than that between soluble free polyphenols and total polyphenol contents. Taken together, the insoluble bound phenolic acids appear to greately contributed to the antioxidant activity in pearled barley.Keywords: barley, antioxidant, insoluble bound phenolic acid, DPPH, ORAC *To whom correspondence should be addressed. E-mail: hohta@nakamura.ac.jp IntroductionCancer mortality rates due to gastric and uterine cancer are decreasing in Japan, while the cancer mortality rates due to lung, colon and breast cancer are on the rise (Ramarathnam et al., 1997). The steady decline in the incidence of gastric cancer in Japan is attributed to a change in eating habits from the traditional Japanese diet to the Western diet. Epidemiological studies indicate that a high consumption of whole cereal products reduce the risk of cardiovascular diseases and certain cancers (World Cancer Research Fund, 1997; Joint WHO/FAO Expert Consultation, 2003). These effects have been ascribed to dietary fibers and phenolic compounds, including procyanidins and cinnamic acids (Bonoli, 2004). Phenolic compounds have been shown to have strong antioxidant activities in vitro and in vivo associated with their ability to scavenge free radicals to break radical chain reactions and to chelate metals. A wide range of antioxidant components with a phenolic structure such as benzoic and cinnamic derivatives, flavonols, chalcones, and flavones (Hernanz et al., 2001; McMurroufh & Madigan, 1996;Goupy et al., 1999) have been found in both their free and bound forms in cereals. The major free phenolic compounds include procyanidins and flavonoids and the major bound phenolic compounds include hydroxycinnamic acid derivatives such as caffeic, p-coumaric and ferulic acids a DGU-14A degasser, a SCL-10A system controller, an SIL-10AXL auto injector, a CTO-10A column oven, a GL Sciences ED 623 ele...

Inhibitory activities of the albedo extracts of 42 species and cultivars of the genus Citrus and those of two Fortunella and one Poncirus species against rat platelet cyclooxygenase and lipoxygenase were screened. Among the species investigated, the extract of Lumie (Citrus lumia) was shown to possess the highest inhibitory activity against cyclooxygenase (IC50 = 24 μg/mL), and that of Shuto (Citrus aurantium) was the highest against lipoxygenase (IC50 = 56 μg/mL). The albedo extracts of citrus from the same taxonomic group appeared to have similar inhibitory tendencies toward these enzymes. The flavedo extract of ripe lumie inhibited cyclooxygenase to the same degree as the albedo, more than the pulp extract. The flavedo, pulp, and juice extracts of ripe Ponkan (C. reticulata) also inhibited lipoxygenase in addition to the albedo extract. Both the flavedo and albedo tissues were shown to be effective sources of inhibitory compounds against cyclooxygenase and lipoxygenase. Keywords: Citrus; platelet cyclooxygenase; platelet lipoxygenase; arachidonic acid