Carbohydrate Peaks Research Articles

Cross-Polarization/Magic Angle Spinning (CP/MAS) 13C Nuclear Magnetic Resonance (NMR) Analysis of Chars from Alkaline-Treated Pyrolyzed Softwood

Pyrolysis chemistry of alkaline-treated loblolly pine is investigated in this study. The pyrolysis experiments were accomplished under an argon atmosphere at 200−400 °C, to determine the effect of alkaline treatment on the char formation. Solid-state cross-polarization/magic angle spinning (CP/MAS) 13C nuclear magnetic resonance (NMR) spectroscopy was used to characterize the chars of the treated and untreated loblolly pine. These studies showed that, in the samples treated with NaOH, there is a shift in the chemical composition of the thermally modified char from cellulosic/hemicellulosic structures to more aryl C structures. At 300 °C, carbohydrate peaks were still present in the char of untreated wood but not in the char of the alkaline-treated wood. This indicated that the addition of NaOH enhanced the thermal degradation of the sugars in the pine sawdust. Our studies also showed that there was an emergence of an aliphatic peak around 12 ppm in the treated pine, which is absent in the spectra of the u...

The use of FTIR microscopy for evaluation of herpes viruses infection development kinetics

The kinetics of Herpes simplex infection development was studied using an FTIR microscopy (FTIR-M) method. The family of herpes viruses includes several members like H. simplex types I and II (HSV I, II), Varicella zoster (VZV) viruses which are involved in various human and animal infections of different parts of the body. In our previous study, we found significant spectral differences between normal uninfected cells in cultures and cells infected with herpes viruses at early stages of the infection. In the present study, cells in cultures were infected with either HSV-I or VZV and at various times post-infection they were examined either by optical microscopy or by advanced FTIR-M. Spectroscopic measurements show a consistent decrease in the intensity of the carbohydrate peak in correlation with the viral infection development, observed by optical microscopy. This decrease in cellular carbohydrate level was used as indicator for herpes viruses infection kinetics. This parameter could be used as a basis for applying a spectroscopic method for the evaluation of herpes virus infection development. Our results show also that the development kinetics of viral infection has an exponential character for these viruses.

Developing mouse embryos progressively eliminate microinjected trehalose

Developing mouse embryos progressively eliminate microinjected trehalose

Molecular fractionation of starch by density-gradient ultracentrifugation

Amylose and amylopectin in corn and potato starches were fractionated by centrifugation at 124,000 g for 3–72 h at 40 °C in a gradient media, Nycodenz, based on their sedimentation rate differences. The fractions were collected from a centrifuge tube, and then analyzed by the phenol–sulfuric acid method and iodine-binding test. Amylopectin, a large and highly branched starch molecule, migrated faster than amylose and quickly reached its isopycnic point with a buoyant density of about 1.25 g/mL, exhibiting a sharp and stable carbohydrate peak. Amylose, which is a relatively small and linear molecule, however, migrated slowly in a broad density range and continued moving to higher density regions, eventually overlapping with amylopectin peak as the centrifugation continued. This could indicate that the buoyant density of amylose is similar to that of amylopectin. Under centrifugal conditions of 3 h and 124,000 g, amylose and amylopectin molecules were clearly separated, and the presence of intermediate starch molecules (11.5 and 7.7% for corn and potato starch, respectively) was also observed between amylose and amylopectin fractions. The amylose content of corn and potato starches was 22.6 and 21.1%, respectively, based on the total carbohydrate analysis after the ultracentrifugation for 3 h. In alkaline gradients (pH 11 or 12.5), the sedimentation rate of starch molecules and the buoyant density of amylopectin were reduced, possibly due to the structural changes induced by alkali.

Organic and inorganic compound variations in haemolymph, epidermal tissue and cuticle over the molt cycle in Scyllaserrata (Decapoda)

Analysis of organic and inorganic compounds in haemolymph, epidermal tissue and cuticle, allowed the correlation of their content variation during the molt cycle in Scylla serrata (Decapoda). The extrusion of carbohydrate, chitin, H 2O- and NaOH-soluble proteins of the epidermal tissue from D2 stage on suggested an early formation of the organic fraction in the new cuticle. The additional secretion of HCl-soluble protein, glycosaminoglycans, calcium, phosphorus and sulfur in D2–D3 stages suggests mineral nucleation shortly before or at ecdysis. This is consistent with the dominant content of proteins and chitin associated with peaks of carbohydrates and GAG-sulfur groups detected in the cuticle immediately after ecdysis. Furthermore, the maximal phosphorus content at this moment suggests calcium, magnesium and manganese phosphate deposits. After an intense accumulation of calcium, chitin and sharp decrease of protein from A to B stages, a constant rate of their deposition in intermolt and dissolution in premolt occurred. The variations concerning proteins, carbohydrates, glycosaminoglycans, calcium, magnesium and sulfur in the haemolymph, before and after ecdysis, suggest a transitory phenomenon for calcium binding and releasing. Other major elements such as, sodium, potassium and chloride may function as osmotic regulators in the haemolymph and in epidermal compartments. The copper profile presented an indicator role for variations of osmolality over the molt cycle.

Waterborne and Surface-Associated Carbohydrates as Settlement Cues for Larvae of the Specialist Marine Herbivore Alderia modesta.

Larvae of the specialist marine herbivore Alderia modesta (Opisthobranchia: Ascoglossa) metamorphose in response to a chemical settlement cue from the alga Vaucheria longicaulis, the obligate adult prey. Bioactivity coeluted with both high and low molecular weight carbohydrates in solution, and with insoluble high molecular weight carbohydrates associated with the algal cell wall. Larvae metamorphosed in response to water conditioned by V. longicaulis, as well as to frozen and homogenized algal tissue. The inducer was efficiently extracted from the algae with boiling water, but after all soluble activity was extracted, residual tissue still induced larval settlement. Ethanol precipitation of a boiled-water extract followed by gel filtration chromatography showed that the precipitate contained carbohydrates of >100,000 Da molecular weight, while the supernatant contained only low molecular weight carbohydrates (<2,000 Da); in both cases all activity was associated with the carbohydrate peak. An aqueous-insoluble 4% NaOH extract was chromatographed in 7 M urea to yield a bioactive high molecular weight carbohydrate peak. Activity was not affected by proteinase K or mild acid hydrolysis, but was significantly decreased by periodate treatment. The results indicate that larvae of A. modesta metamorphose in response to both water-soluble and surface-associated carbohydrates of V. longicaulis, and that the soluble cue exists as both high and low molecular weight isoforms.

The structural composition of humic compounds as indicator of organic carbon sources

Various analytical techniques ( 13C-NMR, FTIR, elemental analysis) have been used to study the structures of humic compounds present in the sediments of Martignano lake located 50 km from Roma city (Italy). The total amount of humic compounds present in the upper layer of sediments is practically constant; instead, considering humic (HA) and fulvic acids (FA) separately, it can be noticed that while HA increase remarkably from A 1 to A 3, FA diminish, probably as a result of the continuous transformation of algal debris, present in large amount in A 1, from compounds which are in an early stage of decomposition to more highly degraded organic matter. In deeper layers the percentage both of HA and FA is constant and slightly lower than that found in the upper layer, except for two sampling points. In these stations the amount of both HA and FA are very high and the carbohydrate peak areas of HA and FA increase along with the depth, reflecting the presence of a well localized source of organic carbon or different environmental conditions.

Estimation of Yeast Glycogen Content from the Mid-Infrared Spectra of Yeast

The mid-infrared spectra of dried yeast samples taken from various stages of the fermentation process were recorded. Because differences were small, the second derivatives of the absorbance spectra were taken to enhance spectral features. Differences noted in the carbohydrate peak regions were related to the relative concentrations of yeast glycogen (energy reserve carbohydrate) and yeast mannan (structural cell wall carbohydrate). The absorbance ratios of glycogen peaks to those of mannan were calculated from the second derivative spectra and were correlated to glycogen values for the same set of yeasts assayed by an enzymatic method. The infrared method offers the advantages of being more rapid and simpler to perform than are enzymatic methods.

Estimation of Yeast Glycogen Content from the Mid-Infrared Spectra of Yeast

The mid-infrared spectra of dried yeast samples taken from various stages of the fermentation process were recorded. Because differences were small, the second derivatives of the absorbance spectra were taken to enhance spectral features. Differences noted in the carbohydrate peak regions were related to the relative concentrations of yeast glycogen (energy reserve carbohydrate) and yeast mannan (structural cell wall carbohydrate). The absorbance ratios of glycogen peaks to those of mannan were calculated from the second derivative spectra and were correlated to glycogen values for the same set of yeasts assayed by an enzymatic method. The infrared method offers the advantages of being more rapid and simpler to perform than are enzymatic methods.

A Kinetic Analysis of the Changes in Infra-Red Spectra of Mechanical Pulps During Irradiation

Photo-induced colour reversion of unbleached thermomechanical pulp under UV irradiation at 320 nm was studied by FT-IR transmission spectroscopy. The changes of peak heights against the irradiation time were analyzed assuming concurrent first-order reaction processes with slow and fast reaction rates, where r S and r F are slow and fast reaction rates, respectively. The values of r S were larger for peaks due to lignin than for peaks due to carbohydrates (cellulose and hemicellulose), and the slow process predominates for both lignin and carbohydrate peaks. Carbohydrate CH bonds decreased more quickly than CO bonds in carbohydrates during irradiation; r S for the peak assignable to carbohydrate sugar ring stretching is very small. Three newly generated peaks at 2981, 1723, and 1190 cm -1 are attributed to lignin break-down products: they are assignable to CH 2 symmetric (in >CH=CH 2 ) or CH 3 asymmetric stretching vibrations, to non-conjugated carbonyl vibrations, and to C-O stretching of free phenol units, respectively. Weight loss of the sample was observed during irradiation

Extraction, purification procedures and HPLC-RI analysis of carbohydrates in olive (Olea europaea L.) plants

Qualitative and quantitative analyses of carbohydrates in olive (Olea europaea L.) tissues have been carried out by HPLC-RI. Sample purification was by two successive solid-liquid extractions to remove completely plant phenolics and pigments. Five carbohydrate peaks; sucrose (stachyose + raffinose + sucrose), glucose, galactose, fructose (fructose + myo-inositol) and mannitol were detected when plant extracts were run on a Sugar SC 1011 column operating at 75°C, using water as eluent 0.5 ml min−1. The use of two serial Sugar SC 1011 columns operating at 90°C and eluting the plant extracts with H2O−CH3CN (95/5 v/v) enables identification and quantification of nine carbohydrates, including tetra and tri-saccharides.

Partial characterization of a non-proteinaceous suppressor of non-specific elicitors from Cladosporium fulvum (syn. Fulvia fulva)

It is our working hypothesis that suppression of the activity of glycoprotein non-specific elicitors (NSE) from fungal cell walls is required in establishment of basic compatibility in the Cladosporium fulvum-tomato system. A suppressor of NSE-induced necrosis on tomato leaves was partially purified from intercellular fluid (IF) obtained from C. fulvum infected, or uninoculated, leaves. The suppressor was stable to treatment with heat, protease, glucosidase, galactosidase, laminarinase, periodate, and mild acid (0·1 N HCl) and base (0·01 N NaOH). Addition of the chelators, EDTA (15 mM) or EGTA (2 mM), to IF resulted in a marked reduction in suppressor activity. Suppressor activity was partially reduced by dialysis of IF, but activity was lost upon dialysis by prior treatment of IF with urea, or with protease which was then inactivated by heating. Activity of a low molecular weight suppressor, partially purified by dialysis and Sephadex G-25 column chromatography, corresponded with a carbohydrate peak. Pectinase or pectinase-generated oligogalacturonides from polypectate suppressed activity of NSE. However, incubation of NSE with pectinase, followed by heat treatment before assay, did not affect NSE activity. It is suggested that low molecular weight suppressor molecules may originate from action of pectolytic enzymes on host cell walls. In addition to these low molecular weight suppressor, native IF, but not heat treated IF, contained proteins that on in vitro incubation with NSE slowly reduced its ability to induce necrosis.

FRUCTANS ISOLATED FROM FLOWERS AND STEMS OF CHRYSANTHEMUM MORIFOLIUM

In order to more fully understand flower growth and development, we are interested in carbohydrate partitioning and metabolism in floricultural crops. In recent work with Chrysanthemum, we noted the occurrence of several early-eluting carbohydrate peaks (as detected by HPLC with a resin-based column in the calcium form). These peaks were present in flowers and stems, and in lesser amounts in leaves. Acid hydrolysis of the unknowns liberated large amounts of fructose and much smaller amounts of glucose, indicating that these peaks are fructans, or medium chain-length fructose polymers. Fructans represented 10% and 25% of the carbohydrate in a 12:5:3 methanol: chloroform: water extract of leaves and stems, respectively. Flower petals were extracted with 95%. ethanol, then with water. Fructans accounted for more than 40'% of the water soluble carbohydrate in flower bud tissue. It is likely that fructans serve as a major reserve carbohydrate in Chrysanthemum. Additional studies are underway to better characterize flower petal fructans, and to understand their role in flower development.

Effects of metalaxyl on elicitor activity, stimulation of glyceollin production and growth of sensitive and tolerant isolates of Phytophthora megasperma f.sp. glycinea

Mutants of Phytophthora megasperma f.sp. glycinea races 1,4 and 6, tolerant to high concentrations of metalaxyl (50- > 500 μg ml −1), were isolated from colonies irradiated with ultraviolet light. When these metalaxyl-tolerant isolates were used to inoculate hypocotyls of compatible soybeans treated with metalaxyl, a majority caused symptoms typical of compatible interactions with rapidly spreading lesions and low levels of glyceollin. This contrasted with the restricted brown lesions with high glyceollin content that developed following inoculation with the parent (metalaxyl-sensitive) isolates. However, a few of the mutant isolates that tolerated 500 μg metalaxyl ml −1 in vitro were sensitive (⩽ 10 μg ml −1) in inoculated plants and caused restricted brown lesions. Comparisons were made of the release of elicitors of glyceollin into culture fluids of a metalaxyl sensitive and a tolerant isolate following addition of metalaxyl to the culture medium. Elicitor activity was increased significantly by metalaxyl treatment in culture fluids of the sensitive isolate but not in those of the tolerant isolate. After fractionation by gel filtration most elicitor activity was detected in fractions corresponding to the second of two carbohydrate peaks. In general, these results are consistent with the possibility that in infected plants, at marginally inhibitory concentrations of metalaxyl, release of elicitors from fungal hyphae may stimulate host-defence responses in otherwise compatible interactions.

テッポウユリの雌ずい物質が花柱内での花粉管伸長に及ぼす影響と受粉による花柱内物質の変動

When stigmatic sap or stylar sap collected by centrifugation was placed on the stylar canals of bisected pistils of Lilium longiflorum, or when pollen grains were pre-soaked in the stigmatic sap, growth of pollen tubes in the style was accelerated even inn self-combination.When stylar sap collected from cross-pollinated styles was placed on the stylar canals of the bisected pistils, the growth of incompatible pollen tubes was significantly promoted more than by the placement of the sap from non- or self-pollinated styles.Changes in constituents of the stylar sap after pollination were also examined. Protein content in the sap decreased in the upper 4/5 of the style in 24 hrs after pollination. Stylar sap eluted through Sephadex G-150 column showed two peaks of carbohydrates, i.e., a broad band of high molecular weight and a narrow band of low molecular weight. After cross-pollination, both peaks were lowered, while after self-pollination only the peak of low molecular weight was lowered.These results suggest that the movement of stylar sap from the stylar tissue to the stylar canal is different between self- and cross-combinations, and that the inhibitory substance for the pollen tubes is absent even in self-combination, and that certain proteoglycans are related to self-incompatibility.

High-resolution solid-state 13C nuclear magnetic resonance of bacterial spores: identification of the alpha-carbon signal of dipicolinic acid

Natural-abundance solid-state 13C nuclear magnetic resonance spectra were obtained for bacterial spores for the first time by using the technique of cross-polarization magic-angle-spinning nuclear magnetic resonance spectroscopy. A resonance at about 150 ppm, detectable in spore samples having a Mn content of less than 0.05%, was consistent with an identification as the alpha-carbon signal of calcium dipicolinate; this signal was missing from a spore sample treated with acid to release dipicolinate and from a spore coat preparation. Carbohydrate peaks were particularly intense in spores and coat preparations of Bacillus macerans. Signals ascribable to beta-hydroxybutyrate were prominent in a B. cereus sample.

Protein—carbohydrate complexes in gluten: Fractionation and proximate composition

The proportions and compositions of carbohydrates associated with the alcohol-soluble (gliadin) and the alcohol-insoluble (glutenin) fractions of a gluten preparation were determined. The alcohol-soluble fraction contained 0·6% (w/w) carbohydrate comprising 55·5% galactose, 20·7% glucose, 16·1% arabinose, 6·2% mannose and 1·2 % xylose. The alcohol-insoluble fraction contained 17·0% carbohydrate comprising 97% glucose and only trace amounts of arabinose, xylose, galactose and mannose. The soluble and the insoluble fractions contained 90 and 83% protein respectively. Gel filtration chromatography of the soluble fraction on Sephadex G-200 resulted in five protein peaks and one carbohydrate peak. The carbohydrate component was eluted with the highest mol. wt. protein peak (at the void volume) and contained 2·9% (w/w) of carbohydrate. The monosaccharide composition of this peak was similar to that of the alcohol-soluble fraction but contained somewhat higher levels of galactose and lower levels of glucose and arabinose. The monosaccharide compositions of the gluten sub-fractions suggested a degree of specificity in the assocation of the non-starch carbohydrates with gluten since the predominant non-starch polysaccharides in flour are arabino-xylans. Polyacrylamide gel electrophoresis at pH 3·1 confirmed that the protein in the carbohydrate-containing peak (Peak I) of the soluble fraction was of high apparent mol. wt. Sodium dodecyl sulfate—polyacrylamide gel electrophoresis of unreduced and reduced fractions showed that peak I contained protein bands normally associated with the glutenin fraction.

Polysaccharide of the slime glycolipoprotein of Pseudomonas aeruginosa.

The polysaccharide moiety was isolated by mild acid hydrolysis from the slime glycolipoprotein of Pseudomonas aeruginosa strain BI. After gel filtration, the polysaccharide obtained from the Carbohydrate peak fractions was found to be lipid- and protein-free. Analyses indicated that the polysaccharide contained the carbohydrate components of the parent glycolipoprotein. Molecular size of the polysaccharide was estimated by gel filtration as 70,000 to 100,000. The polysaccharide showed no indications of toxicity in mice at doses far in excess of the lethal dose for the parent glycolipoprotein, nor did the mice develop the leukopenia that characteristically follows intraperitoneal injection of glycolipoprotein. The polysaccharide acted as an inhibitor of indirect hemagglutination of glycolipoprotein-coated erythrocytes in the presence of anti-glycolipoprotein serum; however, it was not antigenic itself in rabbits. Coupled with methylated bovine serum albumin, the polysaccharide continued to lack the leukopenic and toxic properties of the parent glycolipoprotein, but the coupled polysaccharide was capable of stimulating indirect hemagglutinating antibody against both the polysaccharide and the glycolipoprotein coating erythrocytes. Moreover, the antibody to the coupled polysaccharide protected mice against challenge with lethal doses of viable P. aeruginosa with the same effectiveness as anti-glycolipoprotein serum.

Dissolved carbohydrate and microbial ATP in the North Atlantic: concentrations and interactions

A selective and sensitive spectrophotometric assay for monosaccharide (MCHO) before and after a hydrolysis step has permitted the estimation of total carbohydrate (TCHO) and of polysaccharide (PCHO) by difference. The concentrations and diel variations of MCHO, TCHO, PCHO, and dissolved organic carbon (DOC) were estimated on some 90 samples obtained at 15 stations between Rhode Island and Spain. DOC ranged from 570 to 1330 μg C 1 −1 with a mean of 940 μg C 1 −1. MCHO, calculated as hexose, ranged from 65 to 356 μg 1 −1 (mean 163 μg 1 −1), accounting for 3.5 to 13.2% of the DOC. TCHO varied from 175 to 583 μg 1 −1 (mean 348 μg 1 −1), 8.0 to 24.5% of the DOC. PCHO ranged from 0 to 379 μg 1 −1 (mean 184 μg 1 −1), up to 16.0% of the DOC. MCHO, TCHO, and PCHO were positively correlated with DOC at the 0.01 level. PCHO as a % of TCHO decreased significantlyfrom 69% in coastal to 37% in mid-ocean samples. The vertical distribution of the microbial plankton smaller and larger than 3 μm was determined at 12 of the stations by ATP assay on samples sequentially filtered through Nuclepore membranes. Living biomass for the bacterioplankton (0.2 to 3.0 μm) calculated from the ATP concentration ranged from 1 to 55 μg C 1 −1 (approx 10 4 to 10 6 bacterial cells ml −1) and accounted for 3 to 80% of the total living biomass in the microbial plankton, averaging 30% in the photic and 40% in the aphotic zone. Vertical profiles of bacterial and protist ATP at six stations are compared with those for dissolved carbohydrates, DOC, chlorophyll a, phaeopigments, dissolved oxygen, and temperature. These include four diel drift stations in which a daylight sampling was followed by a predawn resampling on the following day. Carbohydrate peaks were often associated with accumulations of organisms in the > 3- μm size fraction, which were low in chlorophyll a, possibly indicative of collections of protozooplankton. During the day there was evidence of net release of carbohydrate at the depth of the chlorophyll a maxima at oceanic stations but not at neritic stations. Appreciable bacterioplankton maxima (0.2 to 3.0 μm ATP) occurred most often with carbohydrate minima.

Distribution of polysaccharide components of human gastric juice in the electrophoretic partition

A large pool of non-dialyzable solids of normal acid gastric juice was fractionated by paper electrophoresis. Over 350 electrophoretic strips were cut into 5 mm segments and after elution were analyzed for proteins, hexoses, hexosamine, fucose, sialic and uronic acids, and sulfates. The results obtained were correlated with mean electrophoretic patterns of the same gastric juice pool stained by amido black and PAS stains, traced, and analyzed by means of Gaussian curves. Three main protein peaks were found, which were localized in the areas corresponding to that of: (1) pepsin, (2) mucosubstances M2 and M3 (in which albumin is also located) and (3) X1 (where γ-globulin is present). Only one major carbohydrate peak was found, coinciding with that traced by electrophoresis and corresponding to the area of mucosubstance M3, which, on Gaussian curve analysis shows the presence of many components. The carbohydrate spectrum along the electrophoretic partition of the normal gastric juice also changes markedly, and points in the same direction. The anodic area contains highest concentration of sialic acid and hexoses and lower-most of hexosamine and fucose. The central area, which coincides with the carbohydrate peak, contains highest concentrations of hexosamine and fucose and is low in sialic acid. The cathodic area has highest concentration of hexoses, and lowermost of sialic acid, hexosamine and fucose. Sulfates form three peaks, of which the highest is located in the most anodic area, where no proteins and PAS-stainable carbohydrates are detected. The complexity of the distribution of sugars along the electrophoretic partition of the normal acid gastric juice suggests the presence of several carbohydrate materials and proteins of different composition. This indicates the inadequacy of any chemical analysis of the total non-fractionated acid gastric juice. The prevention of proteolysis by means of neutralization of gastric juice in vivo and in vitro simplifies the analytical problems but introduces an artifact which does not exist under physiological conditions in the normal stomach.