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Food Chemistry Sep 2024The wine market has always faced the problem of fraud, including the addition of exogenous sugar solutions to grape musts to increase the final alcohol content. Since in...
The wine market has always faced the problem of fraud, including the addition of exogenous sugar solutions to grape musts to increase the final alcohol content. Since in some countries the practice of chaptalization is prohibited (except by adding concentrated must) it is necessary to broaden the analytical techniques that allow the identification of this type of fraud. The aim of this study was to define an NMR-based sugar profile of genuine grape must to set concentration limits for each sugar as parameters of authenticity. Glucose, fructose, together with eleven minor sugars were quantified in 82 genuine Italian grape musts, developing an analytical procedure based on highly selective chemical shift filters followed by TOCSY. Alongside the characteristic myo- and scyllo-inositol, significant contents of mannose, galactose, and trehalose were also found. Otherwise, maltose, rhamnose, arabinose, sucrose and lactose are present in lower concentrations and show great concentration variability.
Topics: Vitis; Magnetic Resonance Spectroscopy; Wine; Sugars; Fruit
PubMed: 38657517
DOI: 10.1016/j.foodchem.2024.139374 -
Environmental Technology 2023In response to the intensification of eco-friendly routes as a strategy to access compounds of interest, extraction based on hydrothermal technologies is an efficient...
In response to the intensification of eco-friendly routes as a strategy to access compounds of interest, extraction based on hydrothermal technologies is an efficient method to obtain high yields of compounds present in lignocellulosic materials. Accordingly, this study investigated the effects of the combination of ultrasonic pretreatments (energy density, 1.23 × 10-37.6 × 10 J/cm; reaction time, 15 and 60 min) and subcritical water hydrolysis (SWH) (temperature, 220°C; flow rate, 10-30 mL/min; and reaction time, 0.5-15 min) on sugar yield profile from residual biomass of rice, soybean, and pecan. A characterization of the sugars present in the hydrolyzed solutions by high-performance liquid chromatography (HPLC) and a physicochemical evaluation of biomasses by Fourier-transform infrared spectroscopy (FT-IR) was performed. The highest yield reported were 23.8/100 g biomass, 14.4/100 g biomass, and 6.0/100 g biomass for pecan shell, rice shell, and soybean straw, respectively. Cellobiose, glucose, xylose, and arabinose were quantified by the HPLC, as well as inhibitors and organic acids. FT-IR indicated the compositions of the fresh and pretreated samples. Appropriately, the combined application of ultrasonic and SWH methods supported the valorization and optimization of high potential materials generated in agricultural processing.
Topics: Biomass; Ultrasonics; Hydrolysis; Water; Spectroscopy, Fourier Transform Infrared
PubMed: 35226584
DOI: 10.1080/09593330.2022.2048088 -
International Journal of Antimicrobial... Aug 2023Colistin resistance in carbapenem-resistant Klebsiella pneumoniae (CRKP) poses health challenges. To investigate the prevalence and molecular characteristics of...
Colistin resistance in carbapenem-resistant Klebsiella pneumoniae (CRKP) poses health challenges. To investigate the prevalence and molecular characteristics of colistin-resistant CRKP, 708 isolates were collected consecutively from 28 tertiary hospitals in China from 2018 to 2019, and 14 colistin-resistant CRKP were identified. Two-component systems (TCSs) related to colistin resistance (PmrA/B, PhoP/Q, and CrrA/B), the negative regulator mgrB gene and mcr genes, were analysed using genomic sequencing. The relative expression of TCSs genes along with their downstream pmrC and pmrK genes was determined using quantitative real-time PCR (qRT‒PCR). A novel point mutation in PhoQ was confirmed by site-directed mutagenesis, and the subsequent transcriptome changes were analysed by RNA sequencing (RNA-Seq). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used to detect modifications in lipid A. The results showed that only one isolate carried the mcr-8.1 gene, nine exhibited MgrB inactivation or absence, and three exhibited mutations in PmrB. One novel point mutation, L247P, in PhoQ was found to lead to a 64-fold increase in the minimum inhibitory concentration (MIC) of colistin. qRT‒PCR revealed overexpression of phoP/Q and pmrK in isolates with or without MgrB inactivation, and pmrB mutation resulted in overexpression of pmrA and pmrC. Furthermore, transcriptome analysis revealed that the PhoQ L247P novel point mutation caused upregulated expression of phoP/Q and its downstream operon pmrHFIJKLM. Meanwhile, the pmrA/B regulatory pathway did not evolve colistin resistance. Mass spectrometry analysis showed the addition of 4-amino-4-deoxy-L-arabinose (L-Ara4N) to lipid A in colistin-resistant isolates with absence of MgrB. These findings illustrate that the molecular mechanisms of colistin resistance in CRKP isolates are complex, and that MgrB inactivation or absence is the predominant molecular mechanism. Interventions should be initiated to monitor and control colistin resistance.
Topics: Humans; Colistin; Anti-Bacterial Agents; Klebsiella pneumoniae; Prevalence; Lipid A; Bacterial Proteins; Drug Resistance, Bacterial; Carbapenems; Microbial Sensitivity Tests; Klebsiella Infections
PubMed: 37276893
DOI: 10.1016/j.ijantimicag.2023.106873 -
Molecules (Basel, Switzerland) Jul 2023When added to mushroom growing substrates, edible and medicinal herbs affect the mushrooms' nutritional and medicinal value. In this study, polysaccharides (POP-I and...
When added to mushroom growing substrates, edible and medicinal herbs affect the mushrooms' nutritional and medicinal value. In this study, polysaccharides (POP-I and POP-I) were extracted and purified from oyster mushrooms grown on substrates supplemented with 0% and 15% Astragalus roots (P and P), respectively, and their chemical structure and immunobiological activities were compared. POP-I and POP-I were extracted using ultrasound-assisted hot water and deproteinized with the Sevage method, depigmented with 30% HO, desalted with dialysis, and purified using DEAE-52 cellulose and Sephadex G-100 dextran column chromatography. The molecular weight of POP-I and POP-I was 21,706.96 and 20,172.65 Da, respectively. Both were composed of monosaccharides -mannose, galacturonic acid, -glucose, -galactose, and -arabinose but in different molar ratios, and both were connected by a pyranoside linkage. POP-I consisted of higher contents of mannose, glucose, galactose and arabinose and lower content of galacturonic acid as compared to POP-I. Both POP-I and POP-I induced NO and TNF-α production but did not show cytotoxic effect or induce ROS generation in RAW264.7 cells. POP-I showed a stronger ability to promote NO and TNF-α production relative to POP-I. In vitro experiments showed that the immunomodulatory activity of POP-I and POP-I in RAW264.7 macrophages were mediated by the JNK/MAPK, Erk/MAPK, and NF-κB signaling pathways. The results would be helpful for elucidation of the health promoting mechanism of Astragalus oyster mushrooms as a source of neutraceuticals.
Topics: Pleurotus; Tumor Necrosis Factor-alpha; Hydrogen Peroxide; Renal Dialysis; Polysaccharides; Astragalus Plant
PubMed: 37446941
DOI: 10.3390/molecules28135280 -
Carbohydrate Research Jul 2023Type II arabinogalactans (AGs) are a highly diverse class of plant polysaccharides generally encountered as the carbohydrate moieties of certain extracellular... (Review)
Review
Type II arabinogalactans (AGs) are a highly diverse class of plant polysaccharides generally encountered as the carbohydrate moieties of certain extracellular proteoglycans, the so-called arabinogalactan-proteins (AGPs), which are found on plasma membranes and in cell walls. The basic structure of type II AG is a 1,3-β-D-galactan main chain with 1,6-β-D-galactan side chains. The side chains are further decorated with other sugars such as α-l-arabinose and β-d-glucuronic acid. In addition, AGs with 1,6-β-D-galactan as the main chain, which are designated as 'type II related AG' in this review, can also be found in several plants. Due to their diverse and heterogenous features, the determination of carbohydrate structures of type II and type II related AGs is not easy. On the other hand, these complex AGs are scientifically and commercially attractive materials whose structures can be modified by chemical and biochemical approaches for specific purposes. In the current review, what is known about the chemical structures of type II and type II related AGs from different plant sources is outlined. After that, structural analysis techniques are considered and compared. Finally, structural modifications that enhance or alter functionality are highlighted.
Topics: Galactans; Polysaccharides; Carbohydrates
PubMed: 37182471
DOI: 10.1016/j.carres.2023.108828 -
International Journal of Biological... Jul 2023Tumor-associated macrophages (TAMs) with an M2-phenotype mediate gemcitabine resistance to cancer by influencing the metabolic enzymes of gemcitabine and releasing...
Tumor-associated macrophages (TAMs) with an M2-phenotype mediate gemcitabine resistance to cancer by influencing the metabolic enzymes of gemcitabine and releasing competitive deoxycytidine (dC). Our previous studies showed that Danggui Buxue Decoction (DBD), a traditional Chinese medicinal recipe, enhances the anti-tumor activity of gemcitabine in vivo and alleviates gemcitabine-induced myelosuppression. However, the material basis and exact mechanism underlying its enhanced effects remain unclear. In this study, a bioactive polysaccharide consisting of arabinose, mannose, ribose, and glucose was isolated from DBD. In vivo results demonstrated that DBD crude polysaccharide (DBDP) ameliorated gemcitabine-induced immune system disorders. Moreover, DBDP improved the sensitivity of Lewis lung carcinoma-bearing mice to gemcitabine by reshaping the tumor-promoting M2-like macrophages into tumor-inhibiting M1-phenotypes. Furthermore, in vitro results further revealed that DBDP blocked the protective effects of TAMs and M2-macrophages against gemcitabine by inhibiting the excessive secretion of dC and decreasing the high expression of cytidine deaminase. In conclusion, our results demonstrated that DBDP, as the pharmacodynamic material basis of DBD, enhanced the anti-tumor activity of gemcitabine against lung cancer in vitro and in vivo, which was associated with remodeling of the M2-phenotype.
Topics: Mice; Animals; Gemcitabine; Tumor-Associated Macrophages; Drugs, Chinese Herbal; Lung Neoplasms; Polysaccharides
PubMed: 37245770
DOI: 10.1016/j.ijbiomac.2023.125063 -
Carbohydrate Polymers Nov 2023Cereal arabinoxylans (AXs) are complex polysaccharides in terms of their pattern of arabinose and ferulic acid substitutions, which influence their properties in...
Cereal arabinoxylans (AXs) are complex polysaccharides in terms of their pattern of arabinose and ferulic acid substitutions, which influence their properties in structural and nutritional applications. We have evaluated the influence of the molecular structure of three AXs from wheat and rye with distinct substitutions on the activity of β-xylanases from different glycosyl hydrolase families (GH 5_34, 8, 10 and 11). The arabinose and ferulic acid substitutions influence the accessibility of the xylanases, resulting in specific profiles of arabinoxylan-oligosaccharides (AXOS). The GH10 xylanase from Aspergillus aculeatus (AcXyn10A) and GH11 from Thermomyces lanuginosus (TlXyn11) showed the highest activity, producing larger amounts of small oligosaccharides in shorter time. The GH8 xylanase from Bacillus sp. (BXyn8) produced linear xylooligosaccharides and was most restricted by arabinose substitution, whereas GH5_34 from Gonapodya prolifera (GpXyn5_34) required arabinose substitution and produced longer (A)XOS substituted on the reducing end. The complementary substrate specificity of BXyn8 and GpXyn5_34 revealed how arabinoses were distributed along the xylan backbones. This study demonstrates that AX source and xylanase specificity influence the production of oligosaccharides with specific structures, which in turn impacts the growth of specific bacteria (Bacteroides ovatus and Bifidobacterium adolescentis) and the production of beneficial metabolites (short-chain fatty acids).
PubMed: 37659797
DOI: 10.1016/j.carbpol.2023.121233 -
Molecular Imaging and Biology May 2024A major obstacle to targeted cancer therapy is identifying suitable targets that are specifically and abundantly expressed by solid tumors. Certain bacterial strains...
PURPOSE
A major obstacle to targeted cancer therapy is identifying suitable targets that are specifically and abundantly expressed by solid tumors. Certain bacterial strains selectively colonize solid tumors and can deliver genetically encoded cargo molecules to the tumor cells. Here, we engineered bacteria to express monomeric streptavidin (mSA) in tumors, and developed a novel tumor pre-targeting system by visualizing the presence of tumor-associated mSA using a biotinylated imaging probe.
PROCEDURES
We constructed a plasmid expressing mSA fused to maltose-binding protein and optimized the ribosome binding site sequence to increase solubility and expression levels. E. coli MG1655 was transformed with the recombinant plasmid, expression of which is driven by the pBAD promotor. Expression of mSA was induced by L-arabinose 4 days after injection of bacteria into mice bearing CT26 mouse colon carcinoma cells. Selective accumulation of mSA in tumor tissues was visualized by optical imaging after administration of a biotinylated fluorescent dye. Counting of viable bacterial cells was also performed.
RESULTS
Compared with a conventional system, the novel expression system resulted in significantly higher expression of mSA and sustained binding to biotin. Imaging signals in tumor tissues were significantly stronger in the mSA-expressing group than in non-expressing group (P = 0.0005). Furthermore, the fluorescent signal in tumor tissues became detectable again after multiple inductions with L-arabinose. The bacterial counts in tumor tissues showed no significant differences between conditions with and without L-arabinose (P = 0.45). Western blot analysis of tumor tissues confirmed expression and binding of mSA to biotin.
CONCLUSIONS
We successfully engineered tumor-targeting bacteria carrying a recombinant plasmid expressing mSA, which was targeted to, and expressed in, tumor tissues. These data demonstrate the potential of this novel tumor pre-targeting system when combined with biotinylated imaging probes or therapeutic agents.
PubMed: 38814379
DOI: 10.1007/s11307-024-01915-z -
RSC Advances Oct 2023A flexible, efficient, and practical synthesis route was developed to synthesize an OSW-1 disaccharide. The synthesis took 13 steps from l-arabinose and d-xylose...
A flexible, efficient, and practical synthesis route was developed to synthesize an OSW-1 disaccharide. The synthesis took 13 steps from l-arabinose and d-xylose derivatives, and the overall yield was 7.2%. The region preferentially protects various d-xylose hydroxides because the TBS group selectively reacts with this hydroxide at low concentrations due to greater activity at the C-4 hydroxyl of d-xylose. Then, high efficiency selectively protects C-2 hydroxyl and C-3 hydroxyl of d-xylose, respectively. The first high yield of glycosylation on an OSW-1 synthesis disaccharide was achieved by taking sulfide donor 4 with β-PMP anomeric l-arabinose acceptor 12. The cytotoxicity reveals that the analogy has a high IC50 for a variety of cell types. This approach should provide a versatile way to modify OSW-1's disaccharide.
PubMed: 37876654
DOI: 10.1039/d3ra05748h -
Polymers Sep 2023Lotus flower polysaccharide (LFP) and lotus seedpod polysaccharide (LSP) were separated by water extract-alcohol precipitation, and their structures and biological...
Lotus flower polysaccharide (LFP) and lotus seedpod polysaccharide (LSP) were separated by water extract-alcohol precipitation, and their structures and biological activities were investigated. The results of monosaccharide composition showed that LFP and LSP were composed of nine monosaccharides, fucose, rhamnose, arabinose, glucose, galactose, mannose, fructose, galacturonic acid, and glucuronic acid, with the molar percentages of 0.18: 0.43: 2.26: 45.22: 32.14: 4.28: 8.20: 6.28: 1.01 and 2.70: 1.02: 8.15: 45.63: 20.63: 1.44: 2.59: 16.45. LSP and LFP exhibited molecular weights of 9.37 × 10 Da and 1.24 × 10 Da, respectively. SEM showed that LFP and LSP have similar structures; XRD analysis showed that both polysaccharides had crystalline structure and amorphous structure. The results of ABTS+, DPPH, hydroxyl radical scavenging experiment, and a reducing power experiment showed that LFP and LSP had good antioxidant capacity. Cell viability findings showed that polysaccharide concentrations of lotus flower and lotus seedpod could enhance cellular proliferation ranging from 25 to 400 μg/mL without cytotoxicity. By inducing the production of crucial proteins in the TLR4/NF-κB pathway, LFP and LSP were able to induce autophagy in RAW264.7, according to the results of the RT-PCR and Western blotting assays.
PubMed: 37765682
DOI: 10.3390/polym15183828