A survey of metabolic changes in potato leaves by NMR-based metabolic profiling in relation to resistance to late blight disease under field conditions.

Non-targeted nuclear magnetic resonance (NMR)-based metabolic profiling was applied to potato leaves to survey metabolic changes associated with late blight resistance under field conditions. Potato plants were grown in an experimental field, and the compound leaves with no visible symptoms were collected from 20 cultivars/lines at two sampling time points: (i) the time of initial presentation of symptoms in susceptible cultivars and (ii) 12 days before this initiation. 1 H NMR spectra of the foliar metabolites soluble in deuterium oxide- or methanol-d4 -based buffers were measured and used for multivariate analysis. Principal component analysis for six cultivars at symptom initiation showed a class separation corresponding to their levels of late blight resistance. This separation was primarily explained by higher levels of malic acid, methanol, and rutin and a lower level of sucrose in the resistant cultivars than in the susceptible ones. Partial least squares regression revealed that the levels of these metabolites were strongly associated with the disease severity measured in this study under field conditions. These associations were observed only for the leaves harvested at the symptom initiation stage, but not for those collected 12 days beforehand. Subsequently, a simple, alternative enzymatic assay for l-malic acid was used to estimate late blight resistance, as a model for applying the potential metabolic marker obtained. This study demonstrated the potential of metabolomics for field-grown plants in combination with targeted methods for quantifying marker levels, moving towards marker-assisted screening of new cultivars with durable late blight resistance. Copyright © 2016 John Wiley & Sons, Ltd.

Isolation and identification of phenolic compounds accumulated in brown rice grains ripened under high air temperature.

This study aimed to examine the compounds increasing or decreasing in concentration in brown rice grains ripened under high air temperature during ripening using a heat-tolerant cultivar Fusaotome, a heat-intolerant cultivar Hatsuboshi, and an intermediate cultivar Koshihikari. 6-O-Feruloylsucrose (1), 3',6-di-O-sinapoylsucrose (2), 3'-O-sinapoyl-6-O-feruloylsucrose (3), 3',6-di-O-feruloylsucrose (4), cycloartenyl ferulate (5), and 24-methylenecycloartanyl ferulate (6) were isolated from the extracts of brown rice grains. The structures of the isolated compounds (1-6) were elucidated on the basis of spectroscopic analyses. The mean concentrations of compounds 2, 3, and 6 in the grains ripened under high air temperature were markedly higher than those ripened under normal air temperature. In contrast, the mean concentration of compound 5 in the grains ripened under high air temperature was markedly lower than those ripened under normal air temperature. Thus, compounds 2, 3, 5, and 6 constitute potential biomarkers of heat stress in the cultivars used. The mean concentrations of compound 4 in the grains of Fusaotome were the highest in all cultivars. In contrast, the mean concentration of compound 5 in the grains of Fusaotome was the lowest. Therefore, the unique composition of heat-tolerant Fusaotome combines a high concentration of compound 4 with a low concentration of compound 5.

Steroidal glycoalkaloid profiling and structures of glycoalkaloids in wild tomato fruit.

Steroidal glycoalkaloids (SGAs) constitute one of the main groups of secondary metabolites in tomato fruit. However, the detailed composition of SGAs other than α-tomatine, dehydrotomatine and esculeoside A, remains unclear. Comparative SGA profiling was performed in eight tomato accessions, including wild tomato species by HPLC-Fourier transform ion cyclotron resonance mass spectrometry (HPLC-FTICR/MS). On the basis of molecular formulae obtained from accurate m/z and fragmentation patterns by multistage MS/ MS (MS(n)), 123 glycoalkaloids in total were screened. Detailed MS(n) analysis showed that the observed structural diversity was derived from various chemical modifications, such as glycosylation, acetylation, hydroxylation and isomerization. Total SGA content in each tomato accession was in the range of 121-1986 nmol/gfr.wt. Furthermore, the compositional variety of SGA structures was distinctive in some tomato accessions. While most tomato accessions were basically categorized as α-tomatine-rich or esculeoside A-rich group, other specific SGAs also accumulated at high levels in wild tomato. Here, five such SGAs were isolated and their structures were determined by NMR spectroscopic analysis, indicating three of them were presumably synthesized during α-tomatine metabolism.

Monitoring of acrylamide concentrations in potato chips in Japan between 2006 and 2010.

Acrylamide levels in commercially available potato chips in Japan were monitored between August 2006 and June 2010 using the xanthydrol derivative gas chromatography-mass spectrometry (GC-MS) method. Seasonal and annual changes in acrylamide concentrations were determined. Nationwide bimonthly sampling of potato chips was carried out using a four-level design, and seasonal variations were detected in which the minimum acrylamide concentration was observed in August, and the maximum between February and June. Seasonal variations became less apparent after August 2008 as a result of annual effects and/or mitigation measures taken by the potato chip producers. Sampling uncertainties were separated into time-to-time, city-to-city, and lot-to-lot variation, and the largest variation was shown to be lot-to-lot including bag-to-bag.

The usefulness of bright light therapy for patients after oesophagectomy.

OBJECTIVES: The prevention of delirium is an important issue in the field of perioperative nursing. The objective of this study was to verify the usefulness of acute-stage bright light exposure on patients following oesophagectomy. METHODS: The participants were oesophagectomy patients that were removed from their ventilators the day after surgery. After extubation, we assigned the participants to either the exposure group or control group. At Day 2 after surgery, the exposure group underwent two hours of bright light exposure for four days. In both groups, we monitored physical activity and autonomic activity. In addition, we scored the participants on the NEECHAM Scale and evaluated their postoperative delirium and postoperative arrhythmia. RESULTS: On the nights of Days 4 and 5, the amount of activity of the exposure group was significantly lower and The sympathetic nervous index was significantly lower on the night of Day 5. The level of arrhythmia was lower in the exposure group and we observed a significant difference on the night of Day 4 and the daytime of Day 5 after surgery. The occurrence rate of postoperative delirium tended to be lower in the exposure group, but there was no significant difference. None of the participants in the exposure group had NEECHAM Scale scores below the cut-off value from the night of Day 4 onwards. CONCLUSION: We conclude that postoperative bright light exposure adjusted the sleep-wakefulness cycle and improved the bed rest of patients. It was also indicated that bright light therapy is useful for reducing postoperative delirium.

Bile acid-binding ability of kaki-tannin from young fruits of persimmon (Diospyros kaki) in vitro and in vivo.

The bile acid-binding ability of a highly polymerized tannin (kaki-tannin) extracted from dried-young fruits of persimmon (Diospyros kaki) was examined. The kaki-tannin was composed mainly of epicatechin, epigallocatechin, epicatechin-3-O-gallate and epigallocatechin-3-O-gallate. Bile acid-binding ability of kaki-tannin was examined against cholic acid, glycocholic acid, taurocholic acid and deoxycholic acid in vitro, and its effect on fecal bile acid excretion in mice was also examined. Although the bile acid-binding ability of kaki-tannin was weaker than that of cholestyramine, kaki-tannin adsorbed all the bile acids tested and significantly promoted fecal bile acid excretion in mice when supplied at 1% (w/w) in the diet.

Effects of transmaternal exposure to genistein in Hatano high- and low-avoidance rats.

Hatano high- and low-avoidance (HAA and LAA) rats are separated by breeding from Sprague-Dawley rats by high versus low rates of avoidance responses in a shuttle-box task. In addition, compared to HAA rats, LAA rats show lower running-wheel activity, later sexual maturation, 5-day estrous cycling, lower sperm motility, more pronounced immunological reactions, and are generally less reactive to stress. The present study was designed to compare the effects of transmaternal exposure to genistein on these characteristics between HAA and LAA rats. To this aim, litters from both strains were fostered onto Sprague-Dawley rats receiving genistein by gavage with 5 mg/animal/day from day 17 of pregnancy through day 21 of lactation. Inhibited growth after weaning and reduced uterine weight at weaning were observed in the LAA offspring reared by genistein-treated dams. IgM antibody production in response to sheep red blood cells was significantly decreased in the HAA offspring reared by genistein-treated dams. During restraint stress, the plasma concentration of corticosterone was significantly lower in the LAA offspring reared by genistein-treated dams. Strain-related differences were detected in shuttle-box avoidance performance, running-wheel activity, estrous cycling, and sperm motility. The results demonstrate that transmaternal exposure to genistein potentially affects the immunological and stress responses as well as the post-weaning growth of the offspring. It suggests that a comparative study using Hatano rats would be useful for studying the influence of endocrine active chemicals on the whole body systems.

Effects of phenolic compounds on the browning of cooked barley.

Barley grain products undergo browning when cooked. To evaluate effects of phenolic compounds on browning, various amounts of (+)-catechin, proanthocyanidins, or related phenolic compounds were added to aqueous barley extracts or barley pastes, which were heated at 90 degrees C for 1 or 2 h, respectively. In barley extract, (+)-catechin, procyanidin B3 (PCB3), prodelphinidin B3 (PDB3), and a trimer of gallocatechin-gallocatechin-catechin (PDT1) dose-dependently elevated absorbance at 420 nm after heating. PDB3 caused browning faster than PCB3 and (+)-catechin. In barley paste, PDB3 and PDT1 decreased the L* value and increased the a* and b* values of the paste dose-dependently after heating and PCB3 and (+)-catechin did so to a lesser extent. Caffeic acid promoted the browning in both of the extract and paste, while protocatechuic acid, eriodictyol, and (+)-taxifolin promoted it in the extract and myricetin and quercetin promoted it in the paste. Compounds promoting browning have catechol or pyrogallol structures in common.

Location of the auditory egocentre in the blind and normally sighted.

We estimated the location of the auditory egocentre in congenitally blind, late-onset blind, and normally sighted participants, using a revised auditory version of Howard and Templeton's method. The mean location of the auditory egocentre of the congenitally blind participants was found to be close to the midpoint of the interaural axis or the centre of head rotation. It was significantly different from those in the normally sighted and late-onset blind participants, whose mean location of the auditory egocentre was close to the midpoint of the interocular axis or visual egocentre.

Bitter gourd suppresses lipopolysaccharide-induced inflammatory responses.

Bitter gourd ( Momordica charantia L.) is a popular tropical vegetable in Asian countries. Previously it was shown that bitter gourd placenta extract suppressed lipopolysaccharide (LPS)-induced TNFalpha production in RAW 264.7 macrophage-like cells. Here it is shown that the butanol-soluble fraction of bitter gourd placenta extract strongly suppresses LPS-induced TNFalpha production in RAW 264.7 cells. Gene expression analysis using a fibrous DNA microarray showed that the bitter gourd butanol fraction suppressed expression of various LPS-induced inflammatory genes, such as those for TNF, IL1alpha, IL1beta, G1p2, and Ccl5. The butanol fraction significantly suppressed NFkappaB DNA binding activity and phosphorylation of p38, JNK, and ERK MAPKs. Components in the active fraction from bitter gourd were identified as 1-alpha-linolenoyl-lysophosphatidylcholine (LPC), 2-alpha-linolenoyl-LPC, 1-lynoleoyl-LPC, and 2-linoleoyl-LPC. Purified 1-alpha-linolenoyl-LPC and 1-linoleoyl-LPC suppressed the LPS-induced TNFalpha production of RAW 264.7 cells at a concentration of 10 microg/mL.

Analysis of acrylamide in green tea by gas chromatography-mass spectrometry.

Optimization of the solid-phase extraction cleanup procedure enabled the GC-MS analysis of acrylamide in tea samples without the interference of bromination by tea catechins. Although polyvinylpolypyrrolidone (PVPP) is available for removing tea catechins from tea extract, the peaks derived from PVPP had the same retention time as brominated acrylamide in mass chromatograms obtained by GC-MS. A considerable amount of acrylamide was formed at roasting temperatures of > or =120 degrees C; the highest acrylamide level was observed when tea samples were roasted at 180 degrees C for 10 min. Higher temperatures and longer processing times caused a decrease in the acrylamide content. Furthermore, an analysis of 82 tea samples showed that rather than the reducing sugar content, the asparagine content in tea leaves was a significant factor related to acrylamide formation in roasted products. The acrylamide level in roasted tea products was controlled by asparagine in the presence of reducing sugars.

Effects of storage temperature on the contents of sugars and free amino acids in tubers from different potato cultivars and acrylamide in chips.

To clarify the effects of storage temperature on potato components and acrylamide in chips, tubers from five cultivars were stored at various temperatures (2, 6, 8, 10, and 18 degrees C) for 18 weeks, and the contents of sugars, free amino acids in tubers, and acrylamide in chips after frying were analyzed. At temperatures lower than 8 degrees C, the contents of reducing sugars increased markedly in all cultivars, with similar increases in the acrylamide level and dark brown chip color. Free amino acids showed little change at the storage temperatures tested and varied within certain ranges characteristic of each cultivar. The contents of reducing sugars correlated well with the acrylamide level when the fructose/asparagine molar ratio in the tubers was <2. When the fructose/asparagine ratio was >2 by low-temperature storage, the asparagine content, rather than the reducing sugar content, was found to be the limiting factor for acrylamide formation.

Mulberry latex rich in antidiabetic sugar-mimic alkaloids forces dieting on caterpillars.

Since ancient times, mulberry leaves (Morus spp.) have been used to rear the silkworm Bombyx mori. Because the silkworm grows well on mulberry leaves, the toxicities and defensive activities of these leaves against herbivorous insects have been overlooked. Here we show that mulberry leaves are highly toxic to caterpillars other than the silkworm B. mori, because of the ingredients of the latex, a milky sap exuded from mulberry leaf veins. The toxicity of mulberry leaves was lost when the latex was eliminated from the leaves, and artificial diets containing latex showed toxicity. Mulberry latex contained very high concentrations of alkaloidal sugar-mimic glycosidase inhibitors reported to have antidiabetic activities, such as 1,4-dideoxy-1,4-imino-D-arabinitol, 1-deoxynojirimycin, and 1,4-dideoxy-1,4-imino-D-ribitol. The overall concentrations of these inhibitors in latex reached 1.5-2.5% (8-18% dry weight) in several mulberry varieties, which were approximately 100 times the concentrations previously reported from whole mulberry leaves. These sugar-mimic alkaloids were toxic to caterpillars but not to the silkworm B. mori, indicating that the silkworm can circumvent the mulberry tree's defense. Our results suggest that latex ingredients play key roles in defense of this tree and of other plants against insect herbivory, and they imply that plant latexes are treasuries of bioactive substances useful as medicines and pesticides.

Change in content of sugars and free amino acids in potato tubers under short-term storage at low temperature and the effect on acrylamide level after frying.

Changes in the sugar and amino acid contents of potato tubers during short-term storage and the effect on the acrylamide level in chips after frying were investigated. The acrylamide content in chips began to increase after 3 days of storage at 2 degrees C in response to the increase of glucose and fructose contents in the tubers. There was strong correlation between the reducing sugar content and acrylamide level, R(2)=0.873 for fructose and R(2)=0.836 for glucose. The sucrose content had less correlation with the acrylamide content because of its decrease after 4 weeks of storage at 2 degrees C, while the reducing sugar in potato tubers and the acrylamide in chips continued to increase. The contents of the four amino acids, i.e., asparatic acid, asparagine, glutamic acid and glutamine, showed no significant correlation with the acrylamide level. These results suggest that the content of reducing sugars in potato tubers determined the degree of acrylamide formation in chips. The chip color, as evaluated by L* (lightness), was correlated well with the acrylamide content.

Acrylamide in Japanese processed foods and factors affecting acrylamide level in potato chips and tea.

Acrylamide concentrations in processed foods sold in Japanese markets were analyzed by LC-MS/MS and GC-MS methods. Most potato chips and whole potato-based fried snacks showed acrylamide concentration higher than 1000 microg/kg. The concentrations in non-whole potato based Japanese snacks, including rice crackers and candied sweet potatoes, were less tha. 350 microg/kg. Those in instant precooked noodles were less than 100 microg/kg with only one exception. The effect of storage condition of potato tubers on acrylamide concentration in potato chips after frying was also investigated. Sugar content in the tubers increased during cold storage, and the acrylamide concentration increased accordingly. The concentrations of asparagine and other amino acids, however, did not change during the cold storage. High correlations were observed between the acrylamide content in the chips and glucose and fructose contents in the tubers. This fact indicated that the limiting factor for acrylamide formation in potato chips is reducing sugar, not asparagine content in the tubers. Effects of roasting time and temperature on acrylamide concentration in roasted green tea are also described.

Biotransformation of fucoxanthinol into amarouciaxanthin A in mice and HepG2 cells: formation and cytotoxicity of fucoxanthin metabolites.

Fucoxanthin, a major carotenoid in edible brown algae, potentially inhibits the proliferation of human prostate cancer cells via apoptosis induction. However, it has been postulated that dietary fucoxanthin is hydrolyzed into fucoxanthinol in the gastrointestinal tract before absorption in the intestine. In the present study, we investigated the further biotransformation of orally administered fucoxanthin and estimated the cytotoxicity of fucoxanthin metabolites on PC-3 human prostate cancer cells. After the oral administration of fucoxanthin in mice, two metabolites, fucoxanthinol and an unknown metabolite, were found in the plasma and liver. The unknown metabolite was isolated from the incubation mixture of fucoxanthinol and mouse liver preparation (10,000 g supernatant of homogenates), and a series of instrumental analyses identified it as amarouciaxanthin A [(3S,5R,6'S)-3,5,6'-trihydroxy-6,7-didehydro-5,6,7',8'-tetrahydro-beta,epsilon-carotene-3',8'-dione]. The conversion of fucoxanthinol into amarouciaxanthin A was predominantly shown in liver microsomes. This dehydrogenation/isomerization of the 5,6-epoxy-3-hydroxy-5,6-dihydro-beta end group of fucoxanthinol into the 6'-hydroxy-3'-oxo-epsilon end group of amarouciaxanthin A required NAD(P)+ as a cofactor, and the optimal pH for the conversion was 9.5 to 10.0. Fucoxanthinol supplemented to culture medium via HepG2 cells was also converted into amarouciaxanthin A. The 50% inhibitory concentrations on the proliferation of PC-3 human prostate cancer cells were 3.0, 2.0, and 4.6 microM for fucoxanthin, fucoxanthinol, and amarouciaxanthin A, respectively. To our knowledge, this is the first report on the enzymatic dehydrogenation of a 3-hydroxyl end group of xanthophylls in mammals.

Occurrence of antioxidant and radical scavenging proanthocyanidins from the Indian minor spice nagkesar (Mammea longifolia planch and triana syn).

Nagkesar (buds of Mammea longifolia) is extensively used in culinary preparations especially in spice blend in India. Previously thirteen compounds were identified from the medium polar fractions of methanol extract of buds of M. longifolia. In continuation of the study, the polar fraction of methanol extract exhibited stronger antioxidative and radical scavenging activities. An attempt was made to separate and identify the active compounds and found that those were proanthocyanidin oligomers with mean degree of polymerisation ranges from 2 to 10. This is the first report to indicate that Mammea buds contain antioxidant and radical scavenging procyanidin oligomers.

Prenylated flavanones isolated from flowers of Azadirachta indica (the neem tree) as antimutagenic constituents against heterocyclic amines.

Four prenylated flavanones were isolated from the methanol extract of the flowers of Azadirachta indica (the neem tree) as potent antimutagens against Trp-P-1 (3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole) in the Salmonella typhimurium TA98 assay by activity-guided fractionation. Spectroscopic properties revealed that those compounds were 5,7,4'-trihydroxy-8-prenylflavanone (1), 5,4'-dihydroxy-7-methoxy-8-prenylflavanone (2), 5,7,4'-trihydroxy-3',8-diprenylflavanone (3), and 5,7,4'-trihydroxy-3',5'-diprenylflavanone (4). All isolated compounds were found for the first time in this plant. The antimutagenic IC(50) values of compounds 1-4 were 2.7 +/- 0.1, 3.7 +/- 0.1, 11.1 +/- 0.1, and 18.6 +/- 0.1 microM in the preincubation mixture, respectively. These compounds also similarly inhibited the mutagenicity of Trp-P-2 (3-amino-1-methyl-5H-pyrido[4,3-b]indole) and PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine). All of the compounds 1-4 strongly inhibited ethoxyresorufin O-dealkylation activity of cytochrome P450 1A isoforms, which catalyze N-hydroxylation of heterocyclic amines. However, compounds 1-4 did not show significant inhibition against the direct-acting mutagen NaN(3). Thus, the antimutagenic effect of compounds 1-4 would be mainly based on the inhibition of the enzymatic activation of heterocyclic amines.

Effects of physiological changes in potato tubers (Solanum tuberosum L.) after low temperature storage on the level of acrylamide formed in potato chips.

Acrylamide in potato chips made from tubers stored at 2 or 20 degrees C for two weeks after harvest was analyzed by GC-MS. The acrylamide level in the former chips was higher than ten times of that in the latter, which was highly correlated with both glucose and fructose levels in the tubers.

Antimutagenicity of some edible Thai plants, and a bioactive carbazole alkaloid, mahanine, isolated from Micromelum minutum.

The antimutagenic activity against Trp-P-1 of methanolic extracts of 118 samples (108 species) of edible Thai plants was examined by the Ames Test. The activity was evaluated by the amount of plant extracts which suppressed 90% of the mutagenesis (ED90). Five plants, Micromelum minutum, Oroxylum indicum, Cuscuta chinensis, Azadirachta indica, and Litsea petiolata, exhibited significant activity with antimutagenic ED90 values lower than 5 microL/plate (0.1 mg of dry plant material equivalent). The activity-guided fractionation of the extract of M. minutum, which exhibited the highest antimutagenic activity in the screening, resulted in the isolation of an active principle, (+)-mahanine (1) as confirmed by its physicochemical properties. Compound 1 showed a wide variety of biological activity, including antimutagenicity against heterocyclic amines such as Trp-P-1 with an IC50 of 5.2 microM, cytotoxicity against a tumor cell line HL60 with a MIC100 of 4.0 microg/mL, and antimicrobial activity against Bacillus cereus and Staphylococcus aureus with MIC100 values of 6.25 and 12.5 microg/mL, respectively.