Kinds Of Monosaccharides Research Articles

Effect of Monosaccharides Including Rare Sugars on the Bilayer Phase Behavior of Dimyristoylphosphatidylcholine

We observed bilayer phase transitions of dimyristoylphosphatidylcholine (DMPC) in aqueous solutions of four kinds of monosaccharides, namely, D-glucose, D-fructose, D-allose and D-psicose, using differential scanning calorimetry (DSC). D-allose (C3-epimer of D-glucose) and D-psicose (C3-epimer of D-fructose) are rare sugars. We performed DSC measurements using two types of sugar-containing sample dispersions of the DMPC vesicles: one is a normal sample dispersion with no concentration asymmetry between the inside and outside of the vesicles and the other is an unusual sample dispersion with a concentration asymmetry. DSC measurements using normal sample dispersions with different sugar concentrations revealed that the temperatures and transition enthalpies of the pre- and main transition of the DMPC bilayer membrane did not significantly depend on the sugar concentration for all monosaccharides. DSC measurements using the unusual sample dispersions demonstrated that the concentration asymmetry caused the splitting of the endothermic peak of the main transition similarly irrespective of the sort of monosaccharides present. From all these DSC results, we conclude that (i) most monosaccharide molecules exist in the bulk water phase, (ii) no specific interaction depending on the molecular structure of each monosaccharide directly occurs between the DMPC and each monosaccharide molecule, and (iii) almost all the effects of the monosaccharides observed in this study are understandable as the general colligative properties of solutions.

Comparison of Polygonatum sibiricum Polysaccharides Found in Young and Mature Rhizomes.

The main active component of Polygonatum sibiricum (P. sibiricum) rhizome is Polygonatum sibiricum Polysaccharide (PsP) with antioxidant function. At present, only the mature rhizome of P. sibiricum is used to extract PsP, while the young rhizome of by-product is discarded directly as waste, resulting in significant wastage of P. sibiricum resources. We used ultrasound-assisted extraction-deep eutectic solvents (UAE-DESs) method to extract PsP of young and mature rhizomes, respectively. The extraction rate, structure composition and antioxidant ability of PsP between young and mature rhizomes were compared, so as to provide references for comprehensive utilization of P. sibiricum resources. The PsP extraction rate (33.88 ± 1.95%) of young rhizome was close to that (45.08 ± 1.92%) of mature rhizomes. The main component (PsP-2) of the PsP in young rhizome contained six kinds of monosaccharides, which belonged to acidic polysaccharides. The above characteristics of the PsP of young rhizome were similar to those of mature rhizome. The PsP of young rhizome also exhibited similar biological activity to that of the mature rhizome, which indicated even more advantages in DPPH free radical scavenging ability. The results of this study support the utility of the young rhizome, consequently helping to avoid unnecessary waste and provide reference for comprehensive utilization of P. sibiricum.

An acidic heteropolysaccharide rich in galactose and arabinose derived from ginger: Structure and dynamics

Polysaccharide is one of the most important constituents of ginger, exhibiting extensive bioactivities. However, the structures of ginger polysaccharides are poorly understood and remain to be explored. In this study, a polysaccharide UGP1 was isolated from ginger and then a series of chemical, spectroscopic, chromatographic and thermal methods were applied to determine the properties and structure of it. In addition, the digestion and fecal fermentation processes of UGP1 were also investigated. Results showed that the saccharide content of UGP1 was 91.11% ± 0.42% and UGP1 was revealed to be an acidic heteropolysaccharide with helix structure comprised of six kinds of monosaccharide, including galactose, arabinose, rhamnose, glucose, mannose and glucuronic acid, among which galactose (29.32%) and arabinose (19.55%) accounted for the highest proportion. Specifically, in the backbone of UGP1 existed the →4)-α-D-GlcpA-(1→, →3)-α-L-Rhap-(1→, →4,6)-β-D-Galp-(1→, →6)-β-D-Galp-(1→, →3,6)-β-D-Manp-(1→ and →3)-β-D-Glcp-(1→ residues and in the branch chains of UGP1 located the α-L-Araf-(1→ and α-D-Glcp-(1→ residues. Besides, UGP1 was almost not digested by saliva and gastrointestinal tract but could be fermented by gut microbiota into short chain fatty acids (SCFA), containing acetic acid, propionic acid, n-valeric acid and a bit of i-butyric acid and n-butyric acid, which might mediate the interactions between gut microbiota and organisms and thus regulate the health of the human body. The current study reveals the structure of another ginger polysaccharide and helps understand its physiological process, lays the structural foundation of its activities and provides possibility for developing UGP1 into a novel prebiotic.

Mimicking the light harvesting system for sensitive pattern recognition of monosaccharides

Boronate affinity-based indicator displacement assay is a promising approach to develop high performance saccharide sensors. However, it is difficult to improve the sensitivity of saccharide sensors in aqueous solutions due to the highly hydrophilic and hydromimetic nature of saccharides. Inspired by the fact that the natural photosynthesis system uses densely packed dyes with a high energy donor to acceptor ratio to improve the light harvesting efficiency, an enhanced FRET complex named 4Esculetin-BAAP was designed with four coumarin units as the energy donor and one porphyrin moiety as the acceptor. The desired sensor array 4EBSA was then readily constructed by simple dissolving complex 4Esculetin-BAAP in PBS solutions with three different pH values. With this light harvesting mimic strategy, sensor array 4EBSA was determined to be accurate and sensitive for pattern recognition of 7 kinds of monosaccharides in a wide concentration range in both PBS and even 10% serum. Moreover, 4EBSA was successfully applied for distinguishing glucose and its phosphorylated product in mixed form in serum samples with a sensitivity of 0.01 mM and visualized identification of unknown monosaccharide samples.

Characterization ofl-fucose isomerase fromPaenibacillus rhizosphaeraeto producel-fuculose from hydrolyzed fucoidan and commercial fucose

l-Fuculose is a valuable rare sugar that is used to treat a variety of ailments, including HIV, cancer, Hepatitis B, human lysosomal disease (fucosidosis), and cardio-protective medications. The enzymatic approach for the production of l-fuculose using l-fucose as a substrate would be an advantageous method with a wide range of industrial applications. The objective of this study is the characterization of recombinant l-fucose isomerase from Paenibacillus rhizosphaerae (Pa-LFI) for the production of l-fuculose from an inexpensive and natural source (fucoidan) as well as its comparison with commercial l-fucose (Sigma-Aldrich). Fucoidan, a fucose-containing polysaccharide (FPs), was isolated from Undaria pinnatifida, subsequently hydrolyzed, and characterized before the enzymatic production of l-fuculose. The results elaborate that FPs contain 35.9% of fucose along with other kinds of monosaccharides. The purified Pa-LFI exhibited a single band at 65 kDa and showed it as a hexamer with a native molecular mass of 396 kDa. The highest activity of 104.5 U mg-1 of Pa-LFI was perceived at a temperature of 50°C and pH 6.5 in the presence of 1 mM of Mn2+. The Pa-LFI revealed a melting temperature (Tm) of 75°C and a half-life of 12.6 h at 50°C. It exhibited that Pa-LFI with aldose substrate (l-fucose), has a stronger isomerizing activity, disclosing Km,kcat, and kcat/Km 86.2 mM, 32 831 min-1, and 335 min-1 mM-1, respectively. After reaching equilibrium, Pa-LFI efficiently catalyzed the reaction to convert l-fucose into l-fuculose and the conversion ratios of l-fuculose from 100 g L-1 of FPs and commercial fucose were around 6% (5.6 g L-1) and 30% (30.2 g L-1), respectively. According to the findings of the current study, the Pa-LFI will be useful in the manufacturing of l-fuculose using an effective and easy approach that produces no by-products.

Structural characterization and immune-enhancing activity of a novel acid proteoglycan from Black soybean

Black soybean ( Glycine max (L.) merr), as an edible seed of the leguminous plant, possesses a high amount of proteins and carbohydrates. However, few studies have been conducted on the protein-polysaccharide polymer (proteoglycan) in Black soybean. Here, we aim to characterize the proteoglycan in Black soybean. Firstly, a crude extract from Black soybean was obtained by water extraction and alcohol precipitation. Then, DEAE-52 cellulose and Sephadex G-100 column chromatography were used to isolate proteoglycans in the crude extract, and a novel proteoglycan named BBWPS2 was obtained. Moreover, the chemical analysis showed that BBWPS2 was a proteoglycan of 2.02 × 10 5 Da, and composed of 7 kinds of monosaccharides and 16 kinds of amino acids. β -elimination reaction identified the carbohydrate chain was connected to peptide chain with O- glycosidic bonds. Finally, the immunomodulatory tests indicated that BBWPS2 can significantly promote the primary splenocyte proliferation and activate mouse peritoneal macrophages to produce TNF-α. Subsequent pathway studies revealed that BBWPS2 activated macrophages through the mannose receptor-mediated NF-κB/MAPK signaling pathway. Our work indicated that BBWPS2 from Black soybean could be explored as a promising natural immunopotentiator in food and pharmaceutical industries.

Seasonal dynamics of the physicochemical properties of biological crusts exopolysaccharides and the microbial community structure

Exopolysaccharides (EPS), an important substance of cyanobacteria in resisting stresses, are the main form of carbon storage in biocrusts and play an important role in material cycling and stability of biocrusts. In this study, the biocrusts in different seasons (January, April, July, October) were collected from Gurbantunggut Desert, and the dynamics of EPS content, composition, morphological characteristics and microbial community structures were analyzed. The results showed that: 1) The excretion of EPS showed obvious seasonal dynamics. The EPS contents in January, April, July and October were 81.72, 52.46, 76.77, 70.54 μg·cm-2, and the chlorophyll a contents were 2.7, 4.94, 4.2 and 5.98 μg·cm-2, respectively. Cyanobacteria allocated more fixed organic carbon to EPS in winter and summer, and more to their own biomass accumulation in spring and autumn. 2) EPS in biocrusts of each season was composed of seven kinds of monosaccharides. The sum of relative mole percentages of glucose and galactose was 46%-56%, much higher than the other five monosaccharides. The monosaccharide compositions of EPS were significantly affected by temperature and precipitation. There was no significant difference in the Fourier infrared spectra of EPS in biocrusts across different seasons. 3) The observation results of atomic force microscope showed that more filamentous and thick rope-like structures occurred in EPS in July and October, while the EPS showed block-like morphology in January and April. 4) The results of 16S rDNA high-throughput sequencing showed that Cyanobacteria and Microcoleus were the dominant bacterial phyla and genus in biocrusts in all the four seasons, with significantly higher relative abundance than other bacterial phyla and genera. The relative abundance of Proteobacteria was significantly positively correlated with the relative mole percentages of fucose and galactose, indicating that the composition of monosaccharides affected heterotrophic bacteria in crusts. In deserts, environmental factors such as temperature and moisture changed significantly across seasons. The physicochemical properties of biocrust exopolysaccharides and the seasonal dynamics of bacterial communities were controlled by multiple factors, such as temperature, moisture, and light.

Ophiocordyceps lanpingensis polysaccharides alleviate chronic kidney disease through MAPK/NF-κB pathway

Ethnopharmacological relevanceOphiocordyceps lanpingensis (O. lanpingensis) is a traditional ethno-medicine distributed in Eastern Himalayas, which has been used by local minorities to prevent and treat urinary diseases for hundreds of years. However, the corresponding active components and related pharmacological mechanism of such medication are not clear yet. Aims of the studyThis study was performed to investigate the effects and potential mechanisms of O. lanpingensis polysaccharides (OLP) in the treatment of chronic kidney disease (CKD) based on our previous research results. Materials and methodsMethylation analysis was used to investigate the monosaccharide composition and glycosidic linkages in OLP. The animals were divided into the control group, CKD model group, losartan group and three different doses of OLP groups. The CKD mouse model was established by the adenine gavage. The histological changes of renal tissue were observed by Hematoxylin-eosin and Masson staining. Biochemical indicators, including blood urea nitrogen (BUN), serum creatinine (Scr), serum phosphorus (P), plasma calcium (Ca), reactive oxygen species (ROS), superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and malondialdehyde (MDA) were measured to evaluate the alleviation of CKD by OLP. Moreover, the expression levels of a series of cytokines related to the inflammation, apoptosis and fibrosis were analyzed to explore the possible mechanisms of OLP to treat CKD. ResultsOLP is composed of three kinds of monosaccharides. There are eight kinds of glycosidic linkages in OLP, among which →4)-Glcp-(1→ is the main linkage. OLP could significantly attenuate CKD in mice and the tubulointerstitial damage was recovered to almost normal after the treatment of OLP. Compared with the CKD model group, the levels of Scr, BUN, MDA, P in OLP treatment groups were significantly decreased; and the levels of SOD and Ca were increased after OLP treatment. Furthermore, OLP could reduce the oxidative stress of the renal tissues, decrease the expression levels of pro-inflammatory factors through TLR4-mediated MAPK and NF-κB pathway, inhibit the apoptosis of renal cells by MAPK pathway, and relieve the renal fibrosis by down-regulating the expression of TGF-β1. ConclusionsOLP is composed of three kinds of monosaccharides and →4)-Glcp-(1→ is the main glycosidic linkage in the polysaccharide. OLP could ameliorate CKD in mice by declining the oxidative stress, inflammation, apoptosis and fibrosis in the kidneys. The study provided some evidences for the potential application of OLP in alleviating CKD.

Curled Flag Leaf 2, Encoding a Cytochrome P450 Protein, Regulated by the Transcription Factor Roc5, Influences Flag Leaf Development in Rice.

Moderate curling generally causes upright leaf blades, which favors the establishment of ideal plant architecture and increases the photosynthetic efficiency of the population, both of which are desirable traits for super hybrid rice (Oryza sativa L.). In this study, we identified a novel curled-leaf mutant, curled flag leaf 2 (cfl2), which shows specific curling at the base of the flag leaf owing to abnormal epidermal development, caused by enlarged bulliform cells and increased number of papillae with the disordered distribution. Map-based cloning reveals that CFL2 encodes a cytochrome P450 protein and corresponds to the previously reported OsCYP96B4. CFL2 was expressed in all analyzed tissues with differential abundance and was downregulated in the clf1 mutant [a mutant harbors a mutation in the homeodomain leucine zipper IV (HD-ZIP IV) transcription factor Roc5]. Yeast one-hybrid and transient expression assays confirm that Roc5 could directly bind to the cis-element L1 box in the promoter of CFL2 before activating CFL2 expression. RNA sequencing reveals that genes associated with cellulose biosynthesis and cell wall-related processes were significantly upregulated in the cfl2 mutant. The components of cell wall, such as lignin, cellulose, and some kinds of monosaccharide, were altered dramatically in the cfl2 mutant when compared with wild-type “Jinhui10” (WT). Taken together, CFL2, as a target gene of Roc5, plays an important role in the regulation of flag leaf shape by influencing epidermis and cell wall development.

Antioxidant and anti-ageing effects of enzymatic polysaccharide from Pleurotus eryngii residue

The wide industrial cultivation of Pleurotus eryngii (P. eryngii) has resulted in the massive production of mushroom residues (MR) with low-efficiency utilization. In the present study, the P. eryngii enzymatic residue polysaccharide (PERP) was obtained from the P. eryngii residues. The characterization analysis showed that PERP was polysaccharides comprised of five kinds of monosaccharides with molecular weight of 2.05 × 103 Da. PERP also showed rough surface and appeared as spherical structure dispersed in aqueous solution. The animal experiment analysis demonstrated that PERP exhibited potential anti-ageing effects on the brain, liver, kidney and skin, possibly by scavenging reactive radicals, improving the antioxidant status, supressing lipid peroxidation, enhancing organ functions and ameliorating histopathological damage. These results may provide a reference for the efficient utilization of P. eryngii residues in exploring MR-derived functional foods or drugs that delay the ageing process.

Isolation and structural elucidation of a low-molecular-weight polysaccharide from the roots of Panax ginseng C. A. Meyer

A low-molecular-weight polysaccharide named MCGP-L was extracted and purified from the roots of Mountain cultivated ginseng (Panax ginseng C. A. Meyer). The polysaccharide MCGP-L was purified by molecular exclusion chromatography using the Sephadex G-25 column. The average molecular weight of MCGP-L was estimated to be 3 × 103 kDa. Monosaccharide composition analysis showed MCGP-L was composed of three kinds of monosaccharide: D-glucose, D-galactose and D-mannose. The physicochemical properties and structural characteristics of MCGP-L were investigated by the combination of chemical and instrumental analysis such as methylation analysis, High Performance Gel-Permeation Chromatography (HPGPC), High Performance Liquid Chromatography (HPLC) and Nuclear Magnetic Resonance (NMR). The backbone of MCGP-L was composed of (1→4)-linked-α-D-Glcp residues and with branch chain substituted at O-6 position of (1→4,6)-linked-α-D-Glcp. The branch chain consists of →6)-α-D-Galp-(1→, →2)-α-D-Manp-(1→ and β-D-Glcp-(1→.

A comparison between Hydrochloric acid and Trifluoroacetic acid in hydrolysis method of exopolysaccharide from Ophiocordyceps sinensis in Monosaccharide composition analysis by GC-FID

The monosaccharide composition is one of the crucial factors affecting the bioactivity of exopolysaccharide (EPS) in Cordyceps species. Therefore, many scientists have studied, analyzed monosaccharide composition and structure of EPS from Cordyceps species, especially Ophiocordyceps sinensis (O. sinensis). This study aimed to compare hydrochloric acid (HCl) with trifluoroacetic acid (TFA) in the EPS hydrolysis process in monosaccharide composition analysis by Gas Chromatography with Flame-Ionization Detection (GC-FID). The hydrolysis is a crucial step in forming the acetyl derivative, which helps the GC-FID technique to have good results in monosaccharide composition analysis. The results showed that hydrolysis with HCl gave a higher hydrolysis efficiency and was more suitable than hydrolysis by TFA in pretreatment to EPS for GC-FID. Hydrolysis results were analyzed through thin-layer chromatography and high-performance liquid chromatography (HPLC), then Acetyl derivatives were produced and finally analyzed by GC-FID to determine the monosaccharide composition of EPS. For EPS hydrolyzed by HCl, the analytical results presented that this sample had 6 kinds of monosaccharides, including rhamnose, arabinose, xylose, mannose, glucose, and galactose; the most monosaccharide was glucose. The EPS hydrolyzed by TFA only detected three kinds of monosaccharides, including mannose, arabinose, and galactose, mainly mannose. The study has set a foundation for further analysis of monosaccharide composition and structure of EPS from O. sinensis.

Comparative study on the monosaccharide compositions, antioxidant and hypoglycemic activities in vitro of intracellular and extracellular polysaccharides of liquid fermented Coprinus comatus

Polysaccharides were one of the important active ingredients of medical fungi, on account of its unique role caused the widespread concern of researchers at home and abroad. Currently, the structure and antioxidant activity of Coprinus comatus (C. comatus) fruit bodies polysaccharides have been reported. However, there is no article on the simultaneous study of intracellular and extracellular polysaccharides of liquid fermented C. comatus (IPs, EPs) so far. Hence, this paper innovatively investigated the monosaccharide compositions, antioxidative activities and inhibition of α-amylase activity in vitro of IPs and EPs. In this study, we adopted the PMP pre-column derivatization combined with HPLC method to determine the monosaccharide compositions of the IPs and EPs. Besides, the total antioxidant capacity, DPPH radical scavenging capacity, ·OH radical scavenging ability and inhibition effect on α-amylase in vitro of crude polysaccharides (ICPs, ECPs) and deproteinized polysaccharides (IDPs, EDPs) were severally compared. Only three kinds of monosaccharides were detected in IPs. Among the monosaccharides tested, the EPs contained five kinds, of which galactose and xylose accounted for a large proportion. ICPs showed better antioxidant activity and inhibition of α-amylase activity. This article innovatively studied the IPs and EPs, which could lay the foundation for the deep development of C. comatus.

Physicochemical characterization and antioxidant activity of cell-bound exopolysaccharides from Lactobacillus fermentum S1 obtained by two extraction methods

Abstract This study investigated the physicochemical characteristics and antioxidant activities of cell-bound exopolysaccharides (c-EPS) from Lactobacillus fermentum S1 extracted using either phenol (CFP) or ethylenediaminetetraacetic acid (CFE). The extraction products, CFP and CFE, were homogeneous polysaccharides with molecular weights of 2.89 × 105 and 2.44 × 105 Da, respectively. Both CFP and CFE were composed of five kinds of monosaccharides. They had a main chain of β-D-Glcp-(1→2), α-L-Rhap-(1→2), β-D-Galp-(1→3), α-D-Glcp-(1→3), α-D-Galp-(1→3) and β-L-Rhap-(1→3,4) residues, and a tail of α-D-Manp-(1→) residue, but with different molar ratios. Trace amounts of D-Galp-(1→) and L-Araf-(1→2,5) residues were randomly distributed in the sugar chains. Although both CFP and CFE were in triple-helical conformation, they differed from each other in relation to surface morphology and thermal properties. The two c-EPS had different performances in radical scavenging and ferric reducing antioxidant power assays in vitro. The antioxidant capacity of both c-EPS extracts was confirmed in vivo using Caenorhabditis elegans, whose total antioxidant capacity and total superoxide dismutase activity increased after c-EPS treatment. Overall, the extraction method significantly affected the structure and biological activity of c-EPS. Moreover, the potent antioxidant activities of CFP and CFE support their use as natural antioxidants in dietary supplements or food additives.

Polysaccharides from the Edible Mushroom Agaricus bitorquis (Quél.) Sacc. Chaidam Show Anti-hypoxia Activities in Pulmonary Artery Smooth Muscle Cells.

Three kinds of new water-soluble polysaccharides (FA, FB and FC) were isolated from wild mushroom Agaricus bitorquis (Quél.) Sacc. Chaidam by the classical method “water extraction and alcohol precipitation” and purified by column chromatography. The Mw of FA, FB and FC ranged from 5690 Da to 38,340 Da. The three polysaccharide fractions in the fruiting body were mainly composed of 4 kinds of monosaccharides, including glucose, galactose, mannose, and arabinose, among which glucose and galactose were the major monosaccharides. The FTIR and NMR spectroscopy indicated that the skeleton of three fractions composed of a (1→4)-α-D-glycosidic backbone containing α-D-mannopyranose. In vitro anti-hypoxia activity data showed that three polysaccharide fractions possessed a significant effect on inhibiting PASM cells apoptosis under hypoxia. Among them, FC at the concentration of 200 µg/mL revealed a significant anti-hypoxia effect. These results revealed that the intracellular polysaccharides possessed potent anti-hypoxic activity, which might be related to inhibiting LDH and NADPH oxidase expression and promoting the formation of 5-hydroxytryptamine, dopamine, endothelins, acetylcholine. More importantly, FC showed good performance inducing KV1.5 expression and prohibiting KIR6.2 formation at protein level.

Endogenous calcium attenuates the immunomodulatory activity of a polysaccharide from Lycium barbarum L. leaves by altering the global molecular conformation

A heteropolysaccharide, LP5, was purified from Lycium barbarum L. leaves. It was identified as a calcium-rich polysaccharide (8.6 mg calcium/g) with a molecular weight of 2.50 × 105 Da. The polysaccharide was composed of six kinds of monosaccharides, of which mannose and xylose are the main components. And it contains 16.37% glucuronic acid. Studies on RAW264.7 cells demonstrated that this polysaccharide exhibited potent immunomodulatory activity, including an increase in phagocytic activity, as well as the release of both nitric oxide and cytokines. However, after the depletion of calcium, the polysaccharide exhibited greater immunomodulatory activity (p < 0.05). Further conformation analysis confirmed that the polysaccharide changed from a compact spherical conformation to a random coil structure in aqueous solution after the depletion of calcium, which resulted in increased immunomodulatory activity by LP5.

Isolation and Structural Characterization of a Second Polysaccharide from Bulbs of Lanzhou Lily.

In this study, a second water-soluble polysaccharide (designated as LDP-2) was isolated from the bulbs of Lanzhou Lily (Lilium davidii var. unicolor). Based on monosaccharide composition and methylation analysis, its structural features were investigated using a variety of characterizations, such as size-exclusion chromatography combined with laser light scattering (SEC-LLS), gas chromatography-mass spectroscopy (GC-MS), infrared (IR) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. The results demonstrate that LDP-2 is a homogeneous heteropolysaccharide (molecular weight 6.2 × 104Da), which includes four kinds of monosaccharides (Lyx, Man, Glc, and Gal in an approximate weight ratio of 6.74: 6.28: 76.50: 10.48). Furthermore, its morphology, thermal behavior, and preliminary hypoglycemic activities were also investigated.

Polysaccharides from the peels of Citrus aurantifolia induce apoptosis in transplanted H22 cells in mice

In this study, an acidic polysaccharide (CAs) was extracted and purified from the peels of Citrus aurantifolia by Sephadex G-150. HPGPC showed the molecular weight of CAs was about 7.94×106Da. Ion chromatography (IC) analysis showed CAs was mainly composed of rhamnose (Rha), arabinose (Ara), galactose (Gal), glucose (Glu), mannose (Man) and galacturonic acid (GalA), with the molar ratio of 0.67: 7.67: 10.83: 3.83: 4.00: 1.00. 1H and 13C NMR spectra of CAs also identified the presence of five kinds of monosaccharides and galacturonic acid. Moreover, the antitumor activity of CAs was evaluated in mice transplanted H22 hepatoma cells. It was shown that CAs dose-dependently suppressed tumor cells growth with few toxic effects on host. Further investigations revealed that CAs increased the levels of tumor infiltrating CD8+ T lymphocytes, blocked tumor cell cycle in S phase, down-regulated anti-apoptotic protein Bcl-xL and Mcl-1 expression, and led to the activation of caspase 3. These results suggested that CAs had capacity of inducing tumor cells apoptosis in vivo, and it supported considering CAs as an adjuvant reagent in hepatocellular carcinoma treatment.

Structure Elucidation of a Polysaccharide from Umbilicaria esculenta and Its Immunostimulatory Activity.

Umbilicaria esculenta has been used as a tonic food in China for several centuries owing to its pleasant flavor and health benefits. In this study, a water soluble polysaccharide, which we designated as UP2, with an average molecular weight of 3.33 × 105 Da, was isolated from U. esculenta cultivated in the Huangshan Mountain, by consecutive hot water extraction and anion-exchange chromatography. Gas chromatography analysis indicated that UP2 contained three kinds of monosaccharides, including mannose, glucose, and galactose at a molar ratio of 1.7:1.0:1.2. Linkage analysis of UP2 revealed the presence of (1 → 6)-linked glucosyl, (1 → 3,6)-linked glucosyl, t-linked galactosyl, (1 → 6)-linked galactosyl and (1 → 6)-linked mannosyl at a molar ratio of 0.7:4.6:4.1:2.2:9.1. Structural analysis determined that UP2 possessed a backbone consisting of (1 → 6)-linked β-D-glucopyranosyl and (1 → 6)-linked α-D-mannopyranosyl residues, which substituted at the O-3 position of (1 → 6)-linked β-D-glucopyranosyl residues by branches of (1 → 6)-linked α-D-galactopyranosyl and 1-linked β-D-galactopyranosyl residues. Immunostimulatory activity analysis showed that UP2 could stimulate the proliferation of RAW264.7 cells in a dose-dependent manner, and all the samples (20–500 μg/mL) were found to enhance nitric oxide production. The highest phagocytic activity of UP2 was observed at 200 μg/mL. Thus, UP2 may be a potential source of biological and pharmacological agents.

Chromatographic analysis and preparation of l-arabinose from corncob by acid hydrolysis

l-arabinose, a kind of rare sugar, which has already become newly developed functional saccharide with many beneficial biomedical and health effects. In this study, we carried out several experiments to analyze the component of hydrolyzed corncob. Components in the hydrolysate were detected by the methods of ultraviolet spectrogram, HPLC, TLC and High-efficient Thin Layer scanning analysis. The hydrolysis temperature, holding time, concentration of oxalic acid and solid-liquid ratio were investigated as objects by single factor experiments. The results showed that the content of saccharides in the hydrolysate of corncob was up to 72.70%. Three kinds of monosaccharide (d-xylose, l-arabinose, d-glucose) were detected by HPLC analysis and the relative amount of the above three saccharides were 32.8%, 31.4% and 35.7%, respectively. The optimum conditions were: temperature 90°C, holding time 5h, concentration of oxalic acid 6%, solid-liquid ratio 1:12, and the highest l-arabinose yield was 14.89%.