Storage Stability and Thermal Stability of Hordeumin,an Anthocyanin Pigment from Barley

Hordeumin stored at –40 to –80^oC in 1% HCI–methanol suffered neither from color reduction nor discoloration. After heating at 80°C for 60 min, hordeumin showed a pigment retention rate of 100%. This characteristic is because the pigment is a composite high-molecular weight compound consisting of anthocyanins and polyphenols, It was determined, however, that discoloration and browning occurred more rapidly than color reduction during storage and heating of the pigment.     

Antimutagenicity of the purple pigment, hordeumin, from uncooked barley bran-fermented broth

The novel purple pigment hordeumin, an anthocyanin-tannin pigment, was produced from barley bran-fermented broth. The mutagenicity or antimutagenicity of hordeumin was investigated according to the Ames method, an indication of the safety of food, using Salmonella typhimurium TA98. Despite the presence of S-9 mix, hordeumin was not mutagenic. On the other hand, hordeumin effectively decreased a reverse mutation from Trp-P-1, Trp-P-2, IQ, and B[a]P. Furthermore, hordeumin also decreased the reverse mutation from dimethyl sulfoxide extracts of grilled beef.     

Effects of pH and light on the storage stability of the purple pigment, hordeumin, from uncooked barley bran fermented broth

The pigment retention rate of hordeumin was higher than that of two standard anthocyanidins, cyanidin and delphinidin, when hordeumin and anthocyanidins were dissolved in Walpole buffer (pH 1.0) and stored. Moreover, when pigment solutions were stored at 15 degrees C under light irradiation, the pigment retention rate of the hordeumin solution became higher than those of standard anthocyanidins (2 to 10 times) as the storage period increased. Comparing various pH buffers (MacIlvaine buffer, pH 2.2 to 7.0), the pigment retention rate of hordeumin at pH 5.0 was highest. Furthermore, the half-life of hordeumin at pH 5.0 was increased from 9 days to 17.5 days when nitrogen gas was bubbled into the hordeumin solution. We considered that the storage stability of hordeumin is higher than standard anthocyanidins because hordeumin is a complex with anthocyanin, tannin, and protein.     

Effects of pH and Light on the Storage Stability of the Purple Pigment,Hordeumin, from Uncooked Barley Bran Fermented Broth

The pigment retention rate of hordeumin was higher than that of two standard anthocyanidins, cyanidin and delphinidin, when hordeumin and anthocyanidins were dissolved in Walpole buffer (pH 1.0) and stored. Moreover, when pigment solutions were stored at 15°C under light irradiation, the pigment retention rate of the hordeumin solution became higher than those of standard anthocyanidins (2 to 10 times) as the storage period increased. Comparing various pH buffers (MacIlvaine buffer, pH 2.2 to 7.0), the pigment retention rate of hordeumin at pH 5.0 was highest. Furthermore, the half-life of hordeumin at pH 5.0 was increased from 9 days to 17.5 days when nitrogen gas was bubbled into the hordeumin solution. We considered that the storage stability of hordeumin is higher than standard anthocyanidins because hordeumin is a complex with anthocyanin, tannin, and protein.     

Production of purple pigment from green malt and dry malt grains by fermentation without steaming

Summary A large amount of high-molecular-mass anthocyanin pigment was produced by fermentation of malt grains without steaming, in which the malts were used as raw materials. The formation of a purple pigment from green malt was the most prominent from all malt grains tested. The precursor of the purple pigment was presumed to be a polyphenol (proanthocyanidin). When malt was used as the raw material, it allowed the production of pigment without using the glucoamylase preparation that is used for the fermentation of barley bran. In addition, the pigment was produced even from dry malt that had been treated with heat (80°C).     

STIMULATORY PROPERTIES OF FILTRATE FROM THE GREEN ALGA HORMOTILA BLENNISTA. II. FRACTIONATION OF FILTRATE1,2

This investigation reports on the fractionation of filtrate from the green alga Hormotila blennista known to contain autostimulatory properties. Acid, basic, and volatile acid filtrate extracts reduced the lag time of H. blennista at low concentrations. Whole filtrate did not express those lag time reducing capacities which were demonstrated in filtrate extracts. Glycolic acid was identified in both the acid and volatile acid extracts. Growth rate stimulation could not be demonstrated with any filtrate extract. Stimulatory properties of filtrate were shown to be dialyzable and heat labile. It was suggested that heat-labile low molecular weight organic extracellular products are responsible for the growth rate stimulatory property of filtrate. Although dialysis and heat treatments of filtrate removed growth rate stimulation, filtrate properties capable of extending final population levels were retained. High molecular weight heat-stable extracellular products appear to be at least partially responsible for these extended growth levels.     

Direct mass spectrometry approaches to characterize polyphenol composition of complex samples

Lower molecular weight polyphenols including proanthocyanidin oligomers can be analyzed after HPLC separation on either reversed-phase or normal phase columns. However, these techniques are time consuming and can have poor resolution as polymer chain length and structural diversity increase. The detection of higher molecular weight compounds, as well as the determination of molecular weight distributions, remain major challenges in polyphenol analysis.Approaches based on direct mass spectrometry (MS) analysis that are proposed to help overcome these problems are reviewed. Thus, direct flow injection electrospray ionization mass spectrometry analysis can be used to establish polyphenol fingerprints of complex extracts such as in wine. This technique enabled discrimination of samples on the basis of their phenolic (i.e. anthocyanin, phenolic acid and flavan-3-ol) compositions, but larger oligomers and polymers were poorly detectable. Detection of higher molecular weight proanthocyanidins was also restricted with matrix-assisted laser desorption ionization (MALDI) MS, suggesting that they are difficult to desorb as gas-phase ions. The mass distribution of polymeric fractions could, however, be determined by analyzing the mass distributions of bovine serum albumin/proanthocyanidin complexes using MALDI-TOF-MS.     

Correlation between Plant Growth Regulator Release Rate and Bioactivity for the Series of Newly Synthesized Phytoactive Polymers

Phytoactive polymers are high molecular weight systems in which a plant growth regulator (PGR) unit is attached to the polymeric chain by a hydrolyzable chemical bond. The release rate of the PGR is linked to the biological activity of the phytoactive polymer and can be controlled by properties inherent in the whole macromolecular system. In this study the correlation of biological activity and plant growth regulator hydrolytic release rate was investigated for the series of newly synthesized 2,4-dichlorophenoxyacetic acid (2,4-D) polymeric esters. The polymers synthesized differ in their molecular weight, side group structure, and 2,4-D residue content. The influence of these polymer characteristics on the 2,4-D hydrolytic release was investigated, and it was demonstrated that hydrolysis rate substantially depends on the polymer molecular weight, side group structure, and 2,4-D residue content. It was also demonstrated that phytoactive polymer bioactivity depends on the hydrolysis rate of the polymers, and in dependence of this parameter can provide stimulating or inhibiting activity. Biological activity was illustrated by the elongation of wheat and barley coleoptiles.     

Proanthocyanidins from Barley Bran Potentiate Retinoic Acid-induced Granulocytic and Sodium Butyrate-induced Monocytic Differentiation of HL60 Cells

Polyphenol extract from barley bran (BPE) induced nitro blue tetrazolium (NBT) reducing activity and alpha-naphthyl butyrate esterase activity in HL60 human myeloid leukemia cells. Because BPE induced the biochemical markers of HL60 cell differentiation, we investigated the effects of proanthocyanidins isolated from BPE on the HL60 cell differentiation of HL60 cells. Prodelphinidin B-3, T1, T2, and T3 induced 26-40% NBT-positive cells and 22-32% alpha-naphthyl butyrate esterase-positive cells. Proanthocyanidins potentiated retinoic acid (all-trans-retinoic acid)-induced granulocytic and sodium butyrate-induced monocytic differentiation in HL60 cells.     

青稞麸皮油脂肪酸成分分析及其对高血脂症大鼠脂质代谢的影响

为了开发利用资源丰富的青稞麸皮,分析了青稞麸皮油的脂肪酸组成并研究了其对高血脂症大鼠的降血脂作用.通过GC-MS分析,从青稞麸皮油中检测到了10种脂肪酸,并发现其亚油酸含量为75.08%.在青稞麸皮油降血脂实验中,选用24只雄性SD大鼠随机分为空白对照组、高脂模型组和青稞麸皮油组,除空白对照组饲喂普通饲料外,其余各组饲喂高脂饲料并进行干预实验比较.3周后,高脂模型组血清TC、TG、LDL-C和AI 4项指标均显著高于空白对照组(P＜0.05或P＜0.01),而HDL-C/TC显著降低(P＜0.05);青稞麸皮油组的血清TC、TG、LDL-C和AI 4项指标均显著低于高脂模型组(P＜0.05或P＜0.01),而HDL-C/TC显著升高(P＜0.05).结果表明青稞麸皮油对大鼠的高血脂症和动脉硬化的形成有明显的抑制作用,而造成这一结果的原因可能是青稞麸皮油中的高亚油酸含量.     

Hydrolysis of wheat bran and straw by an endoxylanase: production and structural characterization of cinnamoyl-oligosaccharides.

Hydrolysis of wheat bran and wheat straw by a 20.7 kDa thermostable endoxylanase released 35 and 18% of the cell-wall xylan content, respectively. Separation of the cinnamoyl-oligosaccharides (accounting for 6%) from the bulk of total oligosaccharides was achieved by specific anion-exchange chromatography. The cinnamoyl-oligosaccharides were further purified by preparative paper chromatography (PPC) and their molecular weight was determined by MALDI-TOF mass spectrometry. The partially purified hydrolysis end-products contained from 4 to 16 and from 4 to 12 pentose residues for wheat bran and straw, respectively, and only one cinnamic acid per molecule. The primary structure of the new feruloyl arabinoxylopentasaccharide from wheat bran hydrolysis, which has been determined using 2D NMR spectroscopy, is O-beta-D-xylopyranosyl-(1-->4)-O-[5-O- (feruloyl)-alpha-L-arabinofuranosyl-(1-->3)]-O-beta-D-xylopyranosy l-(1-->4) -O-beta-D-xylopyranosyl-(1-->4)-D-xylopyranose.     

Photoactive Subunits of Protochlorophyll(ide) Holochrome

A stable, soluble, and photoactive protochlorophyll(ide) complex has been extracted from dark-grown barley (Hordeum vulgare L.) leaves with buffer containing saponin and glycerol. After ammonium sulfate precipitation, the redissolved pigment complex was partially purified by chromatography on Sephadex gels in the presence of saponin. With the assumptions that the pigment complex from barley has the same shape and density as the proteins used for calibration, its molecular weight is 63,000. Photoactive protochlorophyll(ide) complex isolated from bean (Phaseolus vulgaris L.) and chromatographed by the same procedures has an aparent molecular weight of 100,000 or greater. No chromatographic separation of photoactive and inactive protochlorophyll(ide) complexes was observed. Photoconversion of protochlorophyll(ide) to chlorophyll(ide) did not change the chromatographic behavior of the pigment complex.     

Effect of polyphenol content on the hydrolysis and fermentation of grain sorghum starch

The high polyphenol content of birdproff grain sorghum has been associated with impaired nutritional quality of the grain and with reduced brewing value of birdproof grain sorghum malt due to enzyme inhibition. In this investigation, high polyphenol grain sorghum was evaluated as a feedstock for fermentation ethanol production using NaOH pretreatment to inactivate the polyphenolic compounds prior to hydrolysis with commercial amylases. The polyphenolic inhibition of starch hydrolysis was minimal at a grain sorghum slurry concentration of 20% dry solids, but became pronounced at slurry concentrations of 28% and higher. At these high slurry concentrations the liquefaction and subsequent saccharification and fermentation were markedly improved by alkaline pretreatment. The highest ethanol concentration (12·3%, vol/vol), coupled with the best starch conversion efficiency to ethanol (83·5%), was obtained with a 28% grain sorghum slurry using a partial simultaneous saccharification and fermentation procedure. The residual fermented solids had a crude protein content of 45·4%. Tannic acid decreased yeast cell viability in synthetic media, but had no effect on the hydrolysis or fermentation of grain sorghum starch.     

Manufacture and prebiotic potential of oligosaccharides derived from industrial solid wastes

The solid waste obtained in malting industries when dehulling barley grains, which was mainly made up of barley husks, spent grains and grain fragments, was subjected to a double hydrothermal processing under selected conditions. The liquor from the second stage (containing xylooligosaccharides, XOS) was refined by membrane and ion exchange processing (with or without a previous endoxylanase treatment to reduce the XOS molecular weight). Three XOS concentrates with different purity and/or molecular weight distribution were fermented in vitro with faecal inocula to assess their prebiotic potential. Succinate, lactate, formiate, acetate, propionate and butyrate were generated in fermentations, confirming the prebiotic potential of the various products assayed. The purity of XOS concentrates did not play a significant role in fermentation, whereas the sample with shorter average degree of polymerization presented a faster fermentation kinetics and led to the highest concentration of lactic acid.     

Structural analysis of novel bioactive acylated steryl glucosides in pre-germinated brown rice bran

Previous studies from our laboratory indicated that pre-germinated brown rice (PR) contained certain unknown bioactive lipids that activated two enzymes related to diabetes: Na+/K+ATPase and homocysteine-thiolactonase. In this paper, we report on the isolation and structural characterization of the activator lipids from PR bran as acylated steryl glucosides (ASGs). The activator lipid was isolated by silica gel column chromatography, and its chemical structure was determined by NMR, GC-MS, and tandem mass spectrometry. We demonstrated that the bioactive component consists of a mixture of acylated steryl beta-glucosides. Delta8-cholesterol and 2-hydroxyl stearic acid were identified as constituents of ASGs. The steryl glucosides (SGs) subsequent to alkaline hydrolysis lost this enzyme activator activity. Soybean-derived ASGs were not active. This activity may be quite peculiar to PR-derived ASGs. Our findings suggest that the molecular species of ASG may play an important contributing role in the anti-diabetic properties of a PR diet.     

Effects of tannins and related polyphenols on methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) often acquires multi-drug resistance and is involved in many cases of disease in hospitals. We investigated natural substances directly effective against MRSA or that influence antibiotic resistance. Aloe-emodin, an anthraquinone, and several licorice flavonoids showed potent antibacterial effects against MRSA. Like some hydrolysable tannins (corilagin and tellimagrandin I) and a tea polyphenol [(-)-epicatechin gallate], the licorice flavonoid licoricidin also restored the effects of oxacillin, a beta-lactam antibiotic against MRSA. Further study revealed that theasinensin A, a polyphenol formed from (-)-epigallocatechin gallate, proanthocyanidins obtained from fruits of Zizyphus jujuba var. inermis, and polymeric proanthocyanidins from fruit peels of Zanthoxylum piperitum also suppressed the antibiotic resistance of MRSA.     

Brilliant skyblue pigment formation from gardenia fruits

It is well known that blue pigment is formed by the reaction of amino acids with genipin, the hydrolyzate of geniposide from gardenia fruits. We studied the effect of the amino acid on blue pigment formation and found a linear relationship between the molecular weight of the neutral amino acid and the λ_max of the blue pigment formed. Thin layer chromatographic analysis revealed brilliant skyblue components of the blue pigments formed from glycine, alanine, leucine, phenylalanine and tyrosine. Furthermore, a brilliant skyblue color was obtained by a reverse phase column chromatography (HP-20) of blue pigments formed from glycine, leucine and phenylalanine. The λ_max of these purified pigments lay above 600 nm, and the peaks were sharper than those of crude pigments. After standing for two weeks at 40°C in 40% ethanol solution, the brilliant skyblue pigment formed from genipin and glycine remained stable, losing none of its initial absorbance.     

Purification and characterization of tannase from Paecilomyces variotii: hydrolysis of tannic acid using immobilized tannase

An extracellular tannase (tannin acyl hydrolase) was isolated from Paecilomyces variotii and purified from cell-free culture filtrate using ammonium sulfate precipitation followed by ion exchange and gel filtration chromatography. Fractional precipitation of the culture filtrate with ammonium sulfate yielded 78.7% with 13.6-folds purification, and diethylaminoethyl–cellulose column chromatography and gel filtration showed 19.4-folds and 30.5-folds purifications, respectively. Molecular mass of tannase was found 149.8 kDa through native polyacrylamide gel electrophoresis (PAGE) analysis. Sodium dodecyl sulphate–PAGE revealed that the purified tannase was a monomeric enzyme with a molecular mass of 45 kDa. Temperature of 30 to 50°C and pH of 5.0 to 7.0 were optimum for tannase activity and stability. Tannase immobilized on alginate beads could hydrolyze tannic acid even after extensive reuse and retained about 85% of the initial activity. Thin layer chromatography, high performance liquid chromatography, and ¹H-nuclear magnetic resonance spectral analysis confirmed that gallic acid was formed as a byproduct during hydrolysis of tannic acid.     

Generation of purpura-producing principle from pneumococcal cell walls.

The in vitro kinetics of muramic acid-alanine bond hydrolysis and pneumococcal purpura-producing principle generation by incubation of Streptococcus pneumoniae cell wall preparations with the bacterial autolysin N-acetylmuramyl-L-alanine amidase were similar. The generated purpura-producing principle preparation had a weight-average molecular weight of ca. 2.6 X 10(7) and possessed the glycan and teichoic acid constituents of the pneumococcal cell wall. The results support the idea that the pneumococcal purpura-producing principle is a high-molecular-weight, glycan-teichoic acid fragment released by hydrolysis of the muramic acid-alanine bonds in the bacterial cell wall.     

Messenger and ribosomal RNA hydrolysis by ribonucleases I. The action of two barley leaf ribonucleases on the messenger and ribosomal RNA of isolated polysomes

When barley (Hordeum vulgare L.) leaf polysomes are incubatedwith two RNase fractions (the pH 5 insoluble and soluble RNases)under limit digestion conditions, the two enzymes exhibit characteristicpreference for messenger and ribosomal RNA (mRNA and rRNA) hydrolysis.The pH 5 insoluble RNase from a cultivar of barley, Prior, andthe corresponding enzyme from two near-isogenic lines (M1622and M1623) cleave polysomal mRNA at specific sites and generatepolysome profiles that are unique to the cultivar. By contrast,the soluble RNase from barley leaves, although a typical endoribonuclease,catalyzes no detectable hydrolysis of polysomal mRNA. Both of these barley leaf RNases hydrolyze rRNA when eitherpolysomes or monosomes are treated with these enzymes. Withpolysomes as substrate, the pH 5 insoluble RNase hydrolyzesthe high molecular weight RNA component of both large and smallsubunits of chloroplast and cytoplasmic ribosomes. The solubleRNase preferentially hydrolyzes the high molecular weight RNAcomponent of the small subunit of chloroplast and cytoplasmicribosomes. Analytical gel electrophoresis of the RNA of theRNase-treated monosomes has revealed that both enzymes hydrolyzerRNA into very small fragments. However, despite scission inrRNA at multiple sites, the RNase-treated monosomes remain activein polyuridylate-directed polyphenylalanine synthesis. (Received January 31, 1980; )