Anti-hypertensive substances in fermented soybean,natto

Natto is a traditional Japenese fermented food made by fermenting boiled soy beans withBacillus natto. Its contents of inhibitors against the angiotensin converting enzyme (ACE, EC3.4.15.1) were investigated. Relatively strong inhibitory activity (IC₅₀:0.4 mg/ml, 11.8 inhibition units/g natto) was detected in natto extracts and the inhibitory activity observed in the viscous fraction was more potent than in the bean extract. Two groups of inhibitors in the viscous material, high and low molecular weight inhibitors, were resolved by dialysis test. The inhibitor of high molecular weight was a protein with low IC₅₀ value (0.12 mg/ml). The two types of low molecular weight inhibitors were detected in ethanol extracts (IC₅₀: 0.53 mg/ml and 0.95 mg/ml) and they were found to be stable over a wide range of pH and temperature up to 100°C. They were different in the mode of ACE inhibition. One is competitive, and the other noncompetitive against the hydrolysis of Bz-Gly-His-Leu by ACE.     

Amaranth as a rich dietary source of β-sitosterol and other phytosterols

The analysis of 4 commonly available amaranth varieties (Amaranthus K343, RRC1011, K433, K432) revealed the presence of all three major phytosterols (beta-sitosterol, campesterol, stigmas-terol) with a total sterol content being several fold higher than those found in other studied plants. Substantial differences in total phytosterol content and beta-sitosterol content were found between the amaranth varieties. The most commonly cultivated amaranth variety in the United States, i.e., Amaranthus K343 was found to possess the highest levels of phytosterols of the varieties tested. The possibility of screening for superior amaranth varieties with various health properties is outlined.     

On the fractionation of humic acids by a fractional precipitation technique

When humic acid is investigated from the standpoint of high polymer chemistry, its fractionation is one of the most important and interesting problems. In this paper, some experimental results will be reported on the fractionation of humic acid by the fractional precipitation technique proposed by SCHULZ (I), which had been successfully applied on a soil humic acid by KYUMA (2).     

Tomatidine, a tomato sapogenol, ameliorates hyperlipidemia and atherosclerosis in apoE-deficient mice by inhibiting acyl-CoA:cholesterol acyl-transferase (ACAT)

It was previously revealed that esculeoside A, a new glycoalkaloid, and esculeogenin A, a new aglycon of esculeoside A, contained in ripe tomato ameliorate atherosclerosis in apoE-deficent mice. This study examined whether tomatidine, the aglycone of tomatine, which is a major tomato glycoalkaloid, also shows similar inhibitory effects on cholesterol ester (CE) accumulation in human monocyte-derived macrophages (HMDM) and atherogenesis in apoE-deficient mice. Tomatidine significantly inhibited the CE accumulation induced by acetylated LDL in HMDM in a dose-dependent manner. Tomatidine also inhibited CE formation in Chinese hamster ovary cells overexpressing acyl-CoA:cholesterol acyl-transferase (ACAT)-1 or ACAT-2, suggesting that tomatidine suppresses both ACAT-1 and ACAT-2 activities. Furthermore, the oral administration of tomatidine to apoE-deficient mice significantly reduced levels of serum cholesterol, LDL-cholesterol, and areas of atherosclerotic lesions. The study provides the first evidence that tomatidine significantly suppresses the activity of ACAT and leads to reduction of atherogenesis.     

Induction of reactive oxygen generation and functional changes in mitochondria and their involvement in the development of bacterial rot in lettuce caused by Pseudomonas cichorii

Pseudomonas cichorii is the major causal agent of bacterial rot disease in lettuce, and apoptosis-like programmed cell death is closely associated with disease development. Depletion of cellular ATP and expression of the alternative oxidase gene was observed in lettuce leaves inoculated with P. cichorii suggesting mitochondrial dysfunction. Cytochemical observation showed production of reactive oxygen species in mitochondria of P. cichorii-inoculated lettuce leaf cells. Release of cytochrome c into the cytosol was also induced by inoculation with the bacterium. Superoxide production was observed in the mitochondrial fraction isolated from P. cichorii-infected leaves much more intense than water-treated leaves. Loss of swelling ability was also observed in the mitochondrial fractions following inoculation with P. cichorii. Intriguingly, inhibitors of the mitochondrial respiratory complex III prevented loss of swelling ability, whereas superoxide generation was scarcely affected by inhibitors of mitochondrial permeability transition in the mitochondrial fractions. Inhibitors of the mitochondrial respiratory complex III and mitochondrial permeability transition delayed not only P. cichorii-induced cell death, but also disease development. In contrast, P. cichorii-induced DNA fragmentation was not inhibited in the presence of either type of inhibitor. The findings suggest that mitochondria may play a crucial role in DNA fragmentation-independent cell death pathway(s).     

Spatiotemporal catch distribution of age-0 Pacific bluefin tuna Thunnus orientalis caught by the Japanese troll fishery in relation to surface sea temperature and seasonal migration

This study used a delta-lognormal model to analyze monthly catches of age-0 Pacific bluefin tuna by the troll fishery. The model included fixed effects of month, area, and month–area interaction, and random effects of port, year and port–year interaction. The catch patterns by month and area predicted by the statistical model (standardized catch) revealed that main fishing grounds along the Tsushima Warm Current generally shifted from north to south as the season turned from autumn to winter. In contrast, the standardized catch along the Kuroshio Current did not show such clear spatiotemporal patterns. The standardized catch along the Tsushima Warm Current is significantly associated with average monthly sea surface temperatures in the fishing grounds and consistent with migration routes revealed by tagging experiments in previous studies. These associations indicate the spatiotemporal catch pattern in the Tsushima Warm Current region partly reflects seasonal migration. Knowledge of the possible associations among fish migration, environmental factors and spatiotemporal distribution of the catch will contribute to future management of this species.     

Nickel-catalyzed carbonization of wood for coproduction of functional carbon and fluid fuels II: improved fuel quality of oil fraction and increased heating value of gas fraction

The yields and properties of oil and gas fractions coproduced during carbonization of larch wood loaded with Ni 2%, Ni 2%+Ca 1%, and Ni 4% and without catalyst (None) at 700°–900°C were examined to clarify the catalytic effect in terms of conversion into fluid fuels. The net calorific value of oil occurred mainly below 500°C and increased in the order None < Ni 2% < Ni 4% < Ni 2%+Ca 1%, while the yield decreased in this order. The same order held for the production of gases enriched with hydrogen at 500°–700°C. Even above 800°C, markedly promoted evolution of hydrogen took place for all catalyst systems. These observations confirmed the effectiveness of nickel-catalyzed carbonization at 900°C, particularly Ni 2%+Ca 1%, for both upgrading of oil and gaseous fractions, although the quality of oil was not satisfactory. The catalysis of nickel with and without calcium is discussed on the basis of the modified Broid-Shafizadeh scheme, and the scheme was altered to adapt to the high temperature region where oil was no longer produced. Part of this study was presented at the 14th Annual Meeting of the Japan Institute of Energy, Suita, August 2005, and at the 18th Symposium, Session D, of the Materials Research Society of Japan, Tokyo, December 2007     

Characterization of interactions between barley and various host-specific subgroups of Magnaporthe oryzae and M. grisea

The Magnaporthe oryzae–M. grisea species complex is composed of several host-specific subgroups, but does not contain a barley-specific subgroup. To characterize the relationship between barley and these subgroups, we inoculated 24 barley cultivars separately with each of 18 isolates from various hosts. The interactions between these cultivars and isolates included various reactions from nonhost-like immune responses to typical host responses. Evenly closely related isolates of the blast fungi caused such contrasting reactions. The immune responses of barley cultivars against a Setaria isolate, Si-1J, were examined in detail. An infection assay with near-isogenic fungal strains suggested that PWT1, which was first identified as a major gene conditioning the avirulence of Si-1J on wheat, was involved in the avirulence on two-thirds of the barley cultivars. At the cytological level, the immune responses were associated with both papilla formation and hypersensitive reaction (HR). Of these two, however, HR played a more critical role than papilla formation. Studying the interactions of barley with M. oryzae and M. grisea may reveal various steps in the process of host specialization of a parasite species and the concomitant evolution of host resistance.