Peat and peatified wood are significant carbohydrate resources in tropical rainforests. The carbohydrates of cellulose and hemicellulose are important sources of monosaccharides for both vital activities and industria...Peat and peatified wood are significant carbohydrate resources in tropical rainforests. The carbohydrates of cellulose and hemicellulose are important sources of monosaccharides for both vital activities and industrial applications, such as furan production of furfural and hydroxymethyl furfural. Hydrothermal treatment at 200°C and ultrasonic irradiation pretreatment were used to recover monosaccharides from the abovementioned resources. The monosaccharide recovery from peat was shown to be higher than that from peatified wood. The conversion to organic acids is considered to proceed rapidly because acids are always detected with monosaccharides. This conversion is outstripped by the organic acid-to-gas reaction for treatment times longer than 20 min. The monosaccharide recovery from peatified wood was improved by the ultrasonication pretreatment. It is considered that ultrasonic irradiation broke down lignin blockages, enabling water molecules to access the carbohydrates more easily in the subsequent hydrothermal treatment.展开更多
We developed an HPLC method for analysis of the monosaccharide composition of fucoidans.The fucoidan was hydrolyzed into monosaccharides with 2 mol/L trifluoroacetic acid.Using ribose as the internal standard,the mono...We developed an HPLC method for analysis of the monosaccharide composition of fucoidans.The fucoidan was hydrolyzed into monosaccharides with 2 mol/L trifluoroacetic acid.Using ribose as the internal standard,the monosaccharide derivatives,obtained with 1-Phenyl-3-methyl-5-pyrazolone(PMP),were separated by reverse-phase HPLC using a gradient elution process,and monitored by ultraviolet detection at 245 nm.In the concentration range of 0.1-2.0 mmol/L,the peak area of each monosaccharide had a good linear relationship with its concentration(r2>0.998).The average recoveries of mannose,rhamnose,glucuronic acid,glucose,galactose,xylose,and fucose were 86.2%,95.1%,62.5%,102.0%,94.8%,66.6%,and 105.1%,respectively.This method was accurate and had good reproducibility and could be used to determine the monosaccharide contents of fucoidans.展开更多
Irritable bowel syndrome (IBS) is a lifelong condition with a high prevalence among children and adults. As the diet is a frequent factor that triggers the symptoms, it has been assumed that by avoiding the consumptio...Irritable bowel syndrome (IBS) is a lifelong condition with a high prevalence among children and adults. As the diet is a frequent factor that triggers the symptoms, it has been assumed that by avoiding the consumption of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP), the symptoms might be improved. Therefore, in the past decade, low FODMAP diet has been intensively investigated in the management of IBS. The capacity of FODMAPs to trigger the symptoms in patients with IBS was related to the stimulation of mechanoreceptors in the small and large intestine. This stimulation appears as a response to a combination of increased luminal water (the osmotic effect) and the release of gases (carbon dioxide and hydrogen) due to the fermentation of oligosaccharides and malabsorption of fructose, lactose and polyols. Numerous studies have been published regarding the efficacy of a low FODMAP diet compared to a traditional diet in releasing the IBS symptoms in adults, but there are only a few studies in the juvenile population. The aim of this review is to analyze the current data on both low FODMAP diet in children with IBS and the effects on their nutritional status and physiological development, given the fact that it is a restrictive diet.展开更多
Fourier Transform Infrared Spectroscopy (FTIR) was used to quantify total monosaccharide content in the bacterium Enterobacter cloacae and several of its biofilm mutants. Bacterial biofilm samples were grown on trypti...Fourier Transform Infrared Spectroscopy (FTIR) was used to quantify total monosaccharide content in the bacterium Enterobacter cloacae and several of its biofilm mutants. Bacterial biofilm samples were grown on trypticase soy agar, and 30 μL aliquots of aqueous sample bacterial plus biofilm were deposited into the center of barium fluoride crystals and dried at 50°C for 1-hour before being scanned by FTIR. The total amounts of monosaccharides were estimated using the absorbance of the mono-saccharide peak, 1192 - 958 cm–1, and normalized using the amide II peak, 1585 - 1483 cm–1. This method provided a linear correlation between the absorbance of the monosaccharide peak and concentration of monosaccharide in standard monosaccharides, fructose, glucose, mannose, and rhamnose, over a concentration range of 0.5 - 2.0 mg/mL.展开更多
Oxyphosphorane reacted with glucose to give disaccharide which was confirmed by FAB-MS and 13C-NMR. The mechanism for formation of oligosaccharides through the participation of phosphorus was
Poly(phenylacetylene)s bearing monosaccharide pendant groups are synthesized in high yields by [Rh(nbd)Cl]2 catalyst. The polymers have high molecular weights and give satisfactory spectroscopic data corresponding to ...Poly(phenylacetylene)s bearing monosaccharide pendant groups are synthesized in high yields by [Rh(nbd)Cl]2 catalyst. The polymers have high molecular weights and give satisfactory spectroscopic data corresponding to their molecular structures. They are thermally quite stable (≥300℃) and show strong circular dichroism signals in the visible spectral region owing to the helicity of the polyene backbone. The monosaccharide-containing polyacetylenes are cytophilic and can stimulate the growth of living cells.展开更多
文摘Peat and peatified wood are significant carbohydrate resources in tropical rainforests. The carbohydrates of cellulose and hemicellulose are important sources of monosaccharides for both vital activities and industrial applications, such as furan production of furfural and hydroxymethyl furfural. Hydrothermal treatment at 200°C and ultrasonic irradiation pretreatment were used to recover monosaccharides from the abovementioned resources. The monosaccharide recovery from peat was shown to be higher than that from peatified wood. The conversion to organic acids is considered to proceed rapidly because acids are always detected with monosaccharides. This conversion is outstripped by the organic acid-to-gas reaction for treatment times longer than 20 min. The monosaccharide recovery from peatified wood was improved by the ultrasonication pretreatment. It is considered that ultrasonic irradiation broke down lignin blockages, enabling water molecules to access the carbohydrates more easily in the subsequent hydrothermal treatment.
基金Supported by the Key Technology Research & Development Program of Shandong Province (No 2007GG1005007)
文摘We developed an HPLC method for analysis of the monosaccharide composition of fucoidans.The fucoidan was hydrolyzed into monosaccharides with 2 mol/L trifluoroacetic acid.Using ribose as the internal standard,the monosaccharide derivatives,obtained with 1-Phenyl-3-methyl-5-pyrazolone(PMP),were separated by reverse-phase HPLC using a gradient elution process,and monitored by ultraviolet detection at 245 nm.In the concentration range of 0.1-2.0 mmol/L,the peak area of each monosaccharide had a good linear relationship with its concentration(r2>0.998).The average recoveries of mannose,rhamnose,glucuronic acid,glucose,galactose,xylose,and fucose were 86.2%,95.1%,62.5%,102.0%,94.8%,66.6%,and 105.1%,respectively.This method was accurate and had good reproducibility and could be used to determine the monosaccharide contents of fucoidans.
文摘Irritable bowel syndrome (IBS) is a lifelong condition with a high prevalence among children and adults. As the diet is a frequent factor that triggers the symptoms, it has been assumed that by avoiding the consumption of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP), the symptoms might be improved. Therefore, in the past decade, low FODMAP diet has been intensively investigated in the management of IBS. The capacity of FODMAPs to trigger the symptoms in patients with IBS was related to the stimulation of mechanoreceptors in the small and large intestine. This stimulation appears as a response to a combination of increased luminal water (the osmotic effect) and the release of gases (carbon dioxide and hydrogen) due to the fermentation of oligosaccharides and malabsorption of fructose, lactose and polyols. Numerous studies have been published regarding the efficacy of a low FODMAP diet compared to a traditional diet in releasing the IBS symptoms in adults, but there are only a few studies in the juvenile population. The aim of this review is to analyze the current data on both low FODMAP diet in children with IBS and the effects on their nutritional status and physiological development, given the fact that it is a restrictive diet.
文摘Fourier Transform Infrared Spectroscopy (FTIR) was used to quantify total monosaccharide content in the bacterium Enterobacter cloacae and several of its biofilm mutants. Bacterial biofilm samples were grown on trypticase soy agar, and 30 μL aliquots of aqueous sample bacterial plus biofilm were deposited into the center of barium fluoride crystals and dried at 50°C for 1-hour before being scanned by FTIR. The total amounts of monosaccharides were estimated using the absorbance of the mono-saccharide peak, 1192 - 958 cm–1, and normalized using the amide II peak, 1585 - 1483 cm–1. This method provided a linear correlation between the absorbance of the monosaccharide peak and concentration of monosaccharide in standard monosaccharides, fructose, glucose, mannose, and rhamnose, over a concentration range of 0.5 - 2.0 mg/mL.
文摘Oxyphosphorane reacted with glucose to give disaccharide which was confirmed by FAB-MS and 13C-NMR. The mechanism for formation of oligosaccharides through the participation of phosphorus was
基金This work was partially supported by the Research Grants Council of Hong Kong(Nos. 602706, HKU2/05C, 603505,603304, and 664903).
文摘Poly(phenylacetylene)s bearing monosaccharide pendant groups are synthesized in high yields by [Rh(nbd)Cl]2 catalyst. The polymers have high molecular weights and give satisfactory spectroscopic data corresponding to their molecular structures. They are thermally quite stable (≥300℃) and show strong circular dichroism signals in the visible spectral region owing to the helicity of the polyene backbone. The monosaccharide-containing polyacetylenes are cytophilic and can stimulate the growth of living cells.
