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1.
Int J Biol Macromol ; 279(Pt 4): 135544, 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39265912

RESUMEN

Apricot pectin polysaccharides' fine structure was performed using HPSEC, HPAEC-PAD, GC-MS, NMR and FTIR spectroscopies. Purified pectin fraction (F1AP) was composed of D-galacturonic acid, L-rhamnose, D-arabinose and D-galactose, Mw âˆ¼ 1588 kDa. F1AP was eluted by water and with 0.2 M NaCl from DEAE Sepharose fraction resulting in two distinct fractions, F1AP1 and F1AP6, with different structures, molecular weights, and conformations, providing insights into their structural diversity. F1AP1 neutral properties were related to its association with protein. F1AP1 had a backbone of (1 â†’ 4)-linked-D-galacturonic acid and (1 â†’ 2)-linked-L-rhamnopyranosyl residues branched with arabinogalactan including multiple glycosidic linkages of T-α-Araf, 3-α-Araf, 5-α-Araf, T-α-Arap, 2-α-Arap, t-Galp, 2-Galp, 3-Galp, 4-Galp, 6-Galp, 2,4-Galp, 3,4-Galp, 3,6-Galp and 4,6-Galp side chains, having methyl and acetylated groups, and a high molecular weight (1945 kDa). The Mark-Houwink exponent was 0.276, indicating a compact spherical conformation. While the other F1AP6 fraction consists predominately of less methylated HG regions of pectin polysaccharides. The molar mass of this fraction was 117.5 kDa, which adopted a stiffer and random coil conformation. This knowledge allows us to evaluate how the balance of chemical structure and physical properties of the two pectin domains may manifest itself in the isolated structure of apricot pectin and its applications.

2.
Int J Biol Macromol ; : 135310, 2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39270904

RESUMEN

Sulfation of polysaccharides can affect their biological activity by introducing sulfate groups. Skin burns occur regularly and have a great impact on normal survival. In this study, sulfated arabinogalactan (SAG) was prepared by sulfation, and polyvinyl alcohol (PVA) was used to prepare hydrogels for the treatment of scalded skin in mouse. The results show that the main chain of SAG consists of →3-ß-D-Galactose (Gal)-(1, →3, 6)-ß-D-Gal-(1 and →4)-ß-d-Glucose (Glc)-(1. The chain is a neutral polysaccharide composed of T-ß-L-Arabinose (Araf)-(1→, with a molecular weight of 17.9 kDa. At the same time, PVA + SAG hydrogel can promote the scald repair of mouse skin by promoting collagen deposition and angiogenesis, and regulating the TLR4/MyD88/NF-κB signaling pathway. Interestingly, the effect of SAG on promoting the repair of scald wounds is enhanced after AG is derivatized by sulfation. Therefore, the preparation of SAG by sulfation can promote scald repair, and has great application potential in the field of food and medicine.

3.
Front Bioeng Biotechnol ; 12: 1461343, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39170060

RESUMEN

The arabinogalactan in the representative softwood biomass of larch was degraded using an environmentally friendly hydrogen peroxide and vitamin C (H2O2-VC) system to improve its immunomodulatory activity. Through the H2O2-VC degradation mechanism, hydroxyl radicals are generated, which then target the hydrogen atoms within polysaccharides, resulting in the breaking of glycosidic bonds. Given the impact of oxidative degradation on polysaccharides, we identified three specific arabinogalactan degradation products distinguished by their arabinosyl side chain compositions. The primary structures of the degradation products were investigated using Fourier-transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. Congo red staining showed that the degradation products were absent in the triple-helix structure. The results of the in vitro immunological experiments indicated that an appropriate reduction in the molar ratio of arabinose to galactose enhanced the immunostimulatory effects on RAW 264.7 cells. In addition, the immunostimulatory pathway mediated by arabinogalactan was explored by toll-like receptor 4 (TLR4) inhibitor (TAK-242) These findings provide novel insights into the understanding of the relationship between the structure of arabinogalactan and its biological activity.

4.
Int J Biol Macromol ; 279(Pt 3): 134616, 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39127280

RESUMEN

Arabinogalactan exhibits many biological activities, which is the candidate for functional food ingredients. However, there is limited research on the arabinogalactan from Moringa Oleifera leaf, and its structure needs to be more accurately characterized. This study investigated structural characteristics and immunomodulatory activity of a high-purity polysaccharide from Moringa oleifera leaf (i.e. MOLP-PE) to further explore arabinogalactan from Moringa Oleifera leaf and its potential application area. The results showed that MOLP-PE was a unique type II arabinogalactan: the main chain consisted of → 3, 4)-α-D-Galp-(1→, →3)-ß-D-Galp-(1→ and →2, 4)-ß-D-Rhap-(1→, with branches at the C-4 position of →3, 4)-α-D-Galp-(1→ and →2, 4)-ß-D-Rhap-(1→, consisting of →5)-α-L-Araf-(1→, →3)-α-L-Araf-(1→, →6)-ß-D-Galp-(1→ and →4)-ß-D-GalpA-(1→. Compared with arabinogalactan from larch, galactan and arabinan, MOLP-PE exhibited stronger ability in stimulating proliferation, phagocytosis and cytokines release of macrophages and bound with Toll-like receptor 4 closer via more binding sites, which might be due to its higher contents of 1,3-linked-Galp and 1,5-linked-Araf. These findings elucidated that MOLP-PE, as type II arabinogalactan with a unique structure, could be exploited as an immunomodulatory food ingredient.

5.
Plant Sci ; 348: 112231, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39154893

RESUMEN

In angiosperms, ovules give rise to seeds upon fertilization. Thus, seed formation is dependent on both successful ovule development and tightly controlled communication between female and male gametophytes. During establishment of these interactions, cell walls play a pivotal role, especially arabinogalactan-proteins (AGPs). AGPs are highly glycosylated proteins decorated by arabinogalactan side chains, representing 90 % of the AGP molecule. AGP glycosylation is initiated by a reaction catalysed by hydroxyproline-O-galactosyltransferases (Hyp-GALTs), specifically eight of them (GALT2-9), which add the first galactose to Hyp residues. Five Hyp-GALTs (GALT2, 5, 7, 8 and 9) were previously described as essential for AGP functions in pollen and ovule development, pollen-pistil interactions, and seed morphology. In the present work, a higher order Hyp-GALT mutant (23456789) was studied, with a high degree of under-glycosylated AGPs, to gain deeper insight into the crucial roles of these eight enzymes in female reproductive tissues. Notably, the 23456789 mutant demonstrated a high quantity of unfertilized ovules, displaying abnormal callose accumulation both at the micropylar region and, sometimes, throughout the entire embryo sac. Additionally, this mutant displayed ovules with abnormal embryo sacs, had a disrupted spatiotemporal distribution of AGPs in female reproductive tissues, and showed abnormal seed and embryo development, concomitant with a reduction in AGP-GlcA levels. This study revealed that at least three more enzymes exhibit Hyp-O-GALT activity in Arabidopsis (GALT3, 4 and 6), and reinforces the crucial importance of AGP carbohydrates in carrying out the biological functions of AGPs during plant reproduction.


Asunto(s)
Arabidopsis , Galactosiltransferasas , Óvulo Vegetal , Arabidopsis/crecimiento & desarrollo , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/enzimología , Galactosiltransferasas/metabolismo , Galactosiltransferasas/genética , Óvulo Vegetal/crecimiento & desarrollo , Óvulo Vegetal/genética , Semillas/crecimiento & desarrollo , Semillas/genética , Semillas/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Reproducción , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Mucoproteínas/metabolismo , Mucoproteínas/genética
6.
New Phytol ; 243(6): 2385-2400, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39031531

RESUMEN

Changes in the plant microbiota composition are intimately associated with the health of the plant, but factors controlling the microbial community in flowers are poorly understood. In this study, we used apple flowers and fire blight as a model system to investigate the effects of floral microbiota and microbial competition on disease development and suppression. To compare changes in microbial flora with the RNA expression patterns of plants, the flower samples were collected in three different flowering stages (Bud, Popcorn, and Full-bloom). Using advanced sequencing technology, we analyzed the data and conducted both in vitro and in vivo experiments to validate our findings. Our results show that the Erwinia amylovora use arabinogalactan, which is secreted on the flowers, for early colonization of apple flowers. Pantoea agglomerans was more competitive for arabinogalactan than E. amylovora. Additionally, P. agglomerans suppressed the expression of virulence factors of E. amylovora by using arabinose, which is a major component of arabinogalactan, which induces virulence gene expression. The present data provide new insights into developing control strategies for diverse plant diseases, including fire blight, by highlighting the importance of nutrients in disease development or suppression.


Asunto(s)
Erwinia amylovora , Flores , Galactanos , Malus , Microbiota , Enfermedades de las Plantas , Malus/microbiología , Erwinia amylovora/patogenicidad , Erwinia amylovora/fisiología , Enfermedades de las Plantas/microbiología , Flores/microbiología , Galactanos/metabolismo , Nutrientes/metabolismo , Pantoea/fisiología , Pantoea/genética , Pantoea/patogenicidad , Arabinosa/metabolismo , Factores de Virulencia/genética
7.
J Exp Bot ; 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38980746

RESUMEN

Plant cell walls are complex, multifunctional structures, built up of polysaccharides and proteins. The configuration and abundance of cell wall constituents determine cellular elongation and plant growth. The emphasis of this review is on rice, a staple crop with economic importance, serving as model for grasses/cereals. Recent advancements have contributed to a better understanding of the grass/cereal cell wall. This review brings together the current knowledge about the organisation and metabolism of the rice cell wall, and addresses gaps and missing information connected to the cell wall of rice and the enzymes involved. Several cell wall fractions, including cellulose, mixed-linkage glucans and glucuronoarabinoxylans, are well-understood in rice and other grasses/grains. Conversely, there are still open questions and missing links when it comes down to xyloglucans, glucomannans, pectin, lignin and arabinogalactan proteins. There is still a large and untapped potential to identify carbohydrate-active enzymes (CAZymes), to characterise their activity and to elucidate their involvement in the metabolism of the mentioned cell wall fractions. With this review, we demonstrate the current state and demarcate the research areas with potential for further investigations.

8.
Int J Biol Macromol ; 275(Pt 1): 133535, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38945318

RESUMEN

Petroleum-based packaging materials are nondegradable and unsustainable and thus are harmful to the environment. Renewable packaging films prepared from bio-based raw materials are promising alternatives to petroleum-based packaging materials. In this study, colorless and transparent bio-based films were successfully cast using a solution containing a mixture of arabinogalactan (AG) and poly (vinyl alcohol) (PVA). Vanillin was incorporated into the mixture to endow the films with UV-shielding, antioxidant, and antibacterial properties. The morphological, physical, antioxidant, and antibacterial properties of the blend films were then characterized. At an AG:PVA weight ratio of 1:3, and the vanillin content was 0.15 %, the tensile strength of the AG/PVA/Vanillin (APV) films reached ~28 MPa, while their elongation at break reached ~475 %. The addition of vanillin significantly affected the antioxidant and antibacterial properties of the blend films, which exhibited superb UV barrier capacity. The APV films exhibited extremely low oxygen transmittance, delaying the onset of mold/rot in strawberries and reducing their weight loss. Because of the heat sealability of the blend films, they can be used for encapsulating various substances, such as concentrated laundry liquid. Moreover, the blend films were recyclable and biodegradable. Thus, these films have great potential for applications that require sustainable packaging.


Asunto(s)
Antibacterianos , Antioxidantes , Galactanos , Alcohol Polivinílico , Rayos Ultravioleta , Alcohol Polivinílico/química , Antioxidantes/química , Antioxidantes/farmacología , Antibacterianos/química , Antibacterianos/farmacología , Galactanos/química , Benzaldehídos/química , Calor , Resistencia a la Tracción
9.
Int J Biol Macromol ; 273(Pt 2): 133061, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38866272

RESUMEN

Secondary lymphedema is a chronic and incurable disease lacking satisfactory therapeutic drugs. It primarily results from lymphatic vessel dysfunction resulting from factors such as tumor-related surgery, injury, or infection. Promoting lymphangiogenesis and lymphatic vessel remodeling is crucial for restoring tissue fluid drainage and treating secondary lymphedema. In this study, we discovered that the oral administration of a type-II arabinogalactan (CAPW-1, molecular weight: 64 kDa) significantly promoted lymphangiogenesis and alleviated edema in mice with secondary lymphedema. Notably, the tail diameter of the CAPW-1200 group considerably decreased in comparison to that of the lymphedema group, with an average diameter difference reaching 0.98 mm on day 14. CAPW-1 treatment also reduced the average thickness of the subcutaneous area in the CAPW-1200 group to 0.37 mm (compared with 0.73 mm in the lymphedema group). It also facilitated the return of injected indocyanine green (ICG) from the tail tip to the sciatic lymph nodes, indicating that CAPW-1 promoted lymphatic vessel remodeling at the injury site. In addition, CAPW-1 enhanced the proliferation and migration of lymphatic endothelial cells. This phenomenon was associated with the activation of the toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway, thereby promoting the expression of vascular endothelial growth factor-C (VEGF-C), which can be abolished using a TLR4 antagonist. Despite these findings, CAPW-1 did not alleviate the symptoms of lymphedema or restore lymphatic drainage in VEGFR3flox/flox/Prox1-CreERT2 mice. In summary, CAPW-1 alleviates secondary lymphedema by promoting lymphangiogenesis and lymphatic vessel remodeling through the activation of the TLR4/NF-κB/VEGF-C signaling pathway, indicating its potential as a therapeutic lymphangiogenesis agent for patients with secondary lymphedema.


Asunto(s)
Galactanos , Linfangiogénesis , Vasos Linfáticos , Linfedema , Receptor Toll-Like 4 , Animales , Linfangiogénesis/efectos de los fármacos , Ratones , Linfedema/tratamiento farmacológico , Linfedema/metabolismo , Linfedema/etiología , Vasos Linfáticos/efectos de los fármacos , Vasos Linfáticos/metabolismo , Galactanos/farmacología , Galactanos/química , Receptor Toll-Like 4/metabolismo , Transducción de Señal/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , FN-kappa B/metabolismo , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Movimiento Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Masculino
10.
Polymers (Basel) ; 16(11)2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38891405

RESUMEN

Arabinogalactan (AG), extracted from larch wood, is a ß-1,3-galactan backbone and ß-1,6-galactan side chains with attached α-1-arabinofuranosyl and ß-1-arabinopyranosyl residues. Although the structural characteristics of arabinogalactan II type have already been studied, its functionalization using 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) oxidation remains a promising avenue. In this study, the oxidation of AG, a neutral polysaccharide, was carried out using the TEMPO/NaBr/NaOCl system, resulting in polyuronides with improved functional properties. The oxidation of AG was controlled by analyzing portions of the reaction mixture using spectrophotometric and titration methods. To determine the effect of the TEMPO/NaBr/NaOCl system, air-dried samples of native and oxidized AG were studied by Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy, as well as by gel permeation chromatography. Compounds that model free (1,1-diphenyl-2-picrylhydrazyl (DPPH)) and hydroxyl radicals (iron(II) sulfate, hydrogen peroxide, and salicylic acid) were used to study the antioxidant properties. It was found that, in oxidized forms of AG, the content of carboxyl groups increases by 0.61 mmol compared to native AG. The transformation of oxidized AG into the H+ form using a strong acid cation exchanger leads to an increase in the number of active carboxyl groups to 0.76 mmol. Using FTIR spectroscopy, characteristic absorption bands (1742, 1639, and 1403 cm-1) were established, indicating the occurrence of oxidative processes with a subsequent reduction in the carboxyl group. The functionality of AG was also confirmed by gel permeation chromatography (GPC), which is reflected in an increase in molecular weights (up to 15,700 g/mol). A study of the antioxidant properties of the oxidized and protonated forms of AG show that the obtained antioxidant activity (AOA) values are generally characteristic of polyuronic acids. Therefore, the TEMPO oxidation of AG and other neutral polysaccharides can be considered a promising approach for obtaining compounds with the necessary controlled characteristics.

11.
Int J Mol Sci ; 25(11)2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38892273

RESUMEN

The genus Utricularia (bladderworts) species are carnivorous plants that prey on invertebrates using traps with a high-speed suction mechanism. The outer trap surface is lined by dome-shaped glands responsible for secreting water in active traps. In terminal cells of these glands, the outer wall is differentiated into several layers, and even cell wall ingrowths are covered by new cell wall layers. Due to changes in the cell wall, these glands are excellent models for studying the specialization of cell walls (microdomains). The main aim of this study was to check if different cell wall layers have a different composition. Antibodies against arabinogalactan proteins (AGPs) were used, including JIM8, JIM13, JIM14, MAC207, and JIM4. The localization of the examined compounds was determined using immunohistochemistry techniques and immunogold labeling. Differences in composition were found between the primary cell wall and the cell secondary wall in terminal gland cells. The outermost layer of the cell wall of the terminal cell, which was cuticularized, was devoid of AGPs (JIM8, JIM14). In contrast, the secondary cell wall in terminal cells was rich in AGPs. AGPs localized with the JIM13, JIM8, and JIM14 epitopes occurred in wall ingrowths of pedestal cells. Our research supports the hypothesis of water secretion by the external glands.


Asunto(s)
Pared Celular , Mucoproteínas , Proteínas de Plantas , Pared Celular/metabolismo , Mucoproteínas/metabolismo , Proteínas de Plantas/metabolismo , Lamiales/metabolismo , Inmunohistoquímica
12.
Int J Mol Sci ; 25(12)2024 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-38928328

RESUMEN

Species in the genus Utricularia are carnivorous plants that prey on invertebrates using traps of leaf origin. The traps are equipped with numerous different glandular trichomes. Trichomes (quadrifids) produce digestive enzymes and absorb the products of prey digestion. The main aim of this study was to determine whether arabinogalactan proteins (AGPs) occur in the cell wall ingrowths in the quadrifid cells. Antibodies (JIM8, JIM13, JIM14, MAC207, and JIM4) that act against various groups of AGPs were used. AGP localization was determined using immunohistochemistry techniques and immunogold labeling. AGPs localized with the JIM13, JIM8, and JIM14 epitopes occurred in wall ingrowths of the pedestal cell, which may be related to the fact that AGPs regulate the formation of wall ingrowths but also, due to the patterning of the cell wall structure, affect symplastic transport. The presence of AGPs in the cell wall of terminal cells may be related to the presence of wall ingrowths, but processes also involve vesicle trafficking and membrane recycling, in which these proteins participate.


Asunto(s)
Pared Celular , Mucoproteínas , Proteínas de Plantas , Mucoproteínas/metabolismo , Proteínas de Plantas/metabolismo , Pared Celular/metabolismo , Tricomas/metabolismo , Hojas de la Planta/metabolismo , Lamiales/metabolismo
13.
Nat Prod Res ; : 1-6, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38766905

RESUMEN

Bristled ferula (Ferulopsis hystrix (Bunge) Pimenov) is a perennial plant belonging to the Apiaceae family, and its aqueous extract is utilised in Eastern medicine to treat digestive system diseases. In this study, water-soluble polysaccharides from F. hystrix were isolated for the first time, and the basic polymer FH-3 was separated and characterised. FH-3 was found to contain arabinose and galactose in a 1:5 ratio, with a molecular weight of 52.3 kDa. Methylation analysis confirmed the structure of FH-3 to be arabino-3,6-galactan. Administration of FH-3 at 10 and 30 mg/kg doses in rats with drug-induced gastropathy effectively limited the development of large and strip-like erosions in the gastric mucosa. FH-3 prevented the development of oxidative stress, normalising malondialdehyde (MDA) and catalase (CAT) and reducing glutathione (GSH) serum levels. Arabinogalactan FH-3 is a new gastroprotective and antioxidant plant component in F. hystrix roots, offering promising prospects for treating stomach diseases.

14.
Front Plant Sci ; 15: 1365490, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38571716

RESUMEN

Arabinogalactan proteins (AGPs) are proteoglycans with an unusual molecular structure characterised by the presence of a protein part and carbohydrate chains. Their specific properties at different stages of the fruit ripening programme make AGPs unique markers of this process. An important function of AGPs is to co-form an amorphous extracellular matrix in the cell wall-plasma membrane continuum; thus, changes in the structure of these molecules can determine the presence and distribution of other components. The aim of the current work was to characterise the molecular structure and localisation of AGPs during the fruit ripening process in transgenic lines with silencing and overexpression of SlP4H3 genes (prolyl 4 hydroxylase 3). The objective was accomplished through comprehensive and comparative in situ and ex situ analyses of AGPs from the fruit of transgenic lines and wild-type plants at specific stages of ripening. The experiment showed that changes in prolyl 4 hydroxylases (P4H3) activity affected the content of AGPs and the progress in their modifications in the ongoing ripening process. The analysis of the transgenic lines confirmed the presence of AGPs with high molecular weights (120-60 kDa) at all the examined stages, but a changed pattern of the molecular features of AGPs was found in the last ripening stages, compared to WT. In addition to the AGP molecular changes, morphological modifications of fruit tissue and alterations in the spatio-temporal pattern of AGP distribution at the subcellular level were detected in the transgenic lines with the progression of the ripening process. The work highlights the impact of AGPs and their alterations on the fruit cell wall and changes in AGPs associated with the progression of the ripening process.

15.
Int J Biol Macromol ; 268(Pt 1): 131837, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38663707

RESUMEN

Delayed wound healing is often caused by bacterial infections and persistent inflammation. Multifunctional materials with anti-bacterial, anti-inflammatory, and hemostatic properties are crucial for accelerated wound healing. In this study, we report a biomacromolecule-based scaffold (ArCh) by uniquely combining arabinogalactan (Ar) and chitosan (Ch) using a Schiff-based reaction. Further, the optimized ArCh scaffolds were loaded with Glycyrrhizin (GA: anti-inflammatory molecule) conjugated NIR light-absorbing Copper sulfide (CuS) nanoparticles. The resultant GACuS ArCh scaffolds were characterized for different wound healing parameters in in-vitro and in-vivo models. Our results indicated that GACuS ArCh scaffolds showed excellent swelling, biodegradation, and biocompatibility in vitro. Further results obtained indicated that GACuS ArCh scaffolds demonstrated mild hyperthermia and enhanced hemostatic, anti-oxidant, anti-bacterial, and wound-healing effects when exposed to NIR light. The scaffolds, upon further validation, may be beneficial in accelerating wound healing and tissue regeneration response.


Asunto(s)
Materiales Biocompatibles , Quitosano , Galactanos , Andamios del Tejido , Cicatrización de Heridas , Quitosano/química , Quitosano/farmacología , Cicatrización de Heridas/efectos de los fármacos , Andamios del Tejido/química , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Galactanos/química , Galactanos/farmacología , Regeneración/efectos de los fármacos , Ratones , Antibacterianos/farmacología , Antibacterianos/química , Ratas , Humanos
16.
Carbohydr Polym ; 333: 121974, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38494227

RESUMEN

Astragalus membranaceus polysaccharide (APS) possesses excellent immunomodulatory activity. However, there are several studies on the structural characterization of APS. Here, we aimed to elucidate the repeating units of polysaccharides (APS1, 106.5 kDa; APS2, 114.5 kDa) obtained from different Astragalus membranaceus origins and further investigated their immunomodulatory activities. Based on structural analysis, types of the two polysaccharides were identified as arabinogalactan-I (AG-I) and arabinogalactan-II (AG-II), and co-elution of arabinogalactans (AGs) and α-glucan was observed. The backbone of AG-I was 1,4-linked ß-Galp occasionally substituted by α-Araf at O-2 and/or O-3. AG-II was a highly branched polysaccharide with long branches of α-Araf, which were attached to the O-3 of 1,6-linked ß-Galp of the backbone. The presence of AGs in A. membranaceus was confirmed for the first time. The two polysaccharides could promote the expression of IL-6, IL-1ß and TNF-α in RAW264.7 cells via MAPKs and NF-κB signaling pathways. The constants for APS1 and APS2 binding to Toll-like receptor 4 (TLR4) were 1.83 × 10-5 and 2.08 × 10-6, respectively. Notably, APS2 showed better immunomodulatory activity than APS1, possibly because APS2 contained more AGs. Hence, the results suggested that AGs were the vital components of APS in the immunomodulatory effect.


Asunto(s)
Astragalus propinquus , Galactanos , Galactanos/farmacología , Galactanos/química , Polisacáridos/farmacología , Polisacáridos/química , Transducción de Señal
17.
Polymers (Basel) ; 16(5)2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38475399

RESUMEN

Novel copper-containing bionanocomposites based on the natural raw arabinogalactan have been obtained as universal effective agents against phytopathogen Clavibacter sepedonicus and development stimulants of agricultural plants. Thus, the use of such nanosystems offers a solution to the tasks set in biotechnology while maintaining high environmental standards using non-toxic, biocompatible, and biodegradable natural biopolymers. The physicochemical characteristics of nanocomposites were determined using a number of analytical methods (elemental analysis, transmission electron microscopy and spectroscopic parameters of electron paramagnetic resonance, UV-visible, etc.). The results of the study under the influence of the nanocomposites on the germination of soybean seeds (Glycine max L.) and the vegetation of potatoes (Solanum tuberosum L.) showed the best results in terms of biometric indicators. It is especially worth noting the pronounced influence of the nanocomposite on the development of the root system, and the increase in the mass of the potato root system reached 19%. It is also worth noting that the nanocomposites showed a stimulating effect on the antioxidant system and did not have a negative effect on the content of pigments in potato tissues. Moreover, the resulting bionanocomposite showed a pronounced antibacterial effect against the phytopathogenic bacterium. During the co-incubation of phytopathogen Clavibacter sepedonicus in the presence of the nanocomposite, the number of cells in the bacterial suspension decreased by up to 40% compared to that in the control, and a 10% decrease in the dehydrogenase activity of cells was also detected.

18.
Int J Biol Macromol ; 265(Pt 2): 130859, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38490389

RESUMEN

In this study, crude polysaccharide (LAG-C) and homogeneous arabinogalactan (LAG-W) were isolated from Qinling Larix kaempferi of Shaanxi Province. Bioactivity assays showed that LAG-W and LAG-C enhanced the phagocytic ability, NO secretion, acid phosphatase activity, and cytokine production (IL-6, IL-1ß, and TNF-α) of RAW264.7 macrophages. Notably, LAG-W exhibited a significantly stronger immunomodulatory effect than LAG-C. The primary structure of LAG-W was characterised by chemical methods (monosaccharide composition, methylation analysis, and alkali treatment) and spectroscopic techniques (gas chromatography-mass spectrometry, high-performance liquid chromatography-mass spectrometry, and 1D/2D nuclear magnetic resonance). LAG-W was identified as a 22.08 kilodaltons (kDa) neutral polysaccharide composed of arabinose and galactose at a 1:7.5 molar ratio. Its backbone consisted of repeated →3)-ß-Galp-(1→ residues. Side chains, connected at the O-6 position, were mainly composed of T-ß-Galp-(1→ and T-ß-Galp-(1→6)-ß-Galp-(1→ residues. And it also contained small amounts of T-ß-Arap-(1→, T-α-Araf-(1→6)-ß-Galp-(1→6)-ß-Galp-(1→, and T-α-Araf-(1→3)-α-Araf-(1→6)-ß-Galp-(1→ residues. By structurally and functionally characterising L. kaempferi polysaccharides, this study opens the way for the valorisation of this species.


Asunto(s)
Larix , Galactanos/farmacología , Galactanos/química , Polisacáridos/farmacología , Polisacáridos/química , Espectroscopía de Resonancia Magnética
19.
Protoplasma ; 261(5): 911-926, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38499789

RESUMEN

Alterations in cell wall composition imply in new structural and functional traits in gall developmental sites, even when the inducer is a sucking exophytophagous insect with strict feeding sites as the aphid associated to Malus domestica Borkh. This host plant is an economically important, fruit-bearing species, susceptible to gall induction by the sucking aphid Eriosoma lanigerum Hausmann, 1802. Herein, the immunocytochemical detection of arabinogalactan-proteins (AGPs), pectins, and hemicelluloses using monoclonal antibodies was performed in samples of non-galled roots and stems, and of root and stem galls on M. domestica. The dynamics of these cell wall components was discussed under the structural and functional traits of the galls proximal, median, and distal regions, according to the proximity of E. lanigerum colony feeding site. In the proximal region, the epitopes of AGPs and homogalacturonans (HGs) are related to cell growth and divisions, which result in the overproduction of parenchyma cells both in root and stem galls. In the proximal and median regions, the co-occurrence of HGs and arabinans in the cell walls of parenchyma and secondary tissues favors the nutrient flow and water-holding capacity, while the xylogalacturonans and hemicelluloses may function as additional carbohydrate resources to E. lanigerum. The immunocytochemical profile of the cell walls support the feeding activity of E. lanigerum mainly in the gall proximal region. The similarity of the cell wall components of the gall distal region and the non-galled portions, both in roots and stems, relates to the decrease of the cecidogenetic field the more distant the E. lanigerum colony is.


Asunto(s)
Pared Celular , Inmunohistoquímica , Malus , Raíces de Plantas , Tallos de la Planta , Tumores de Planta , Pared Celular/química , Pared Celular/metabolismo , Animales , Raíces de Plantas/parasitología , Tallos de la Planta/química , Tumores de Planta/parasitología , Mucoproteínas/metabolismo , Áfidos/fisiología , Polisacáridos/metabolismo , Polisacáridos/química , Proteínas de Plantas/metabolismo , Proteínas de Plantas/química , Pectinas/metabolismo
20.
Methods Mol Biol ; 2791: 71-80, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38532093

RESUMEN

Immunocytochemical studies of the cell wall are used to visualize specific epitopes of pectins, arabinogalactan proteins, hemicelluloses, extensins, and other wall components using specific primary antibodies. This reaction, combined with calcofluor staining, allows to comprehend how the cell wall is rebuilt during the protoplast culture. In this protocol, the method of immunostaining using antibodies against cell wall components based on Fagopyrum esculentum and Fagopyrum tataricum protoplasts is described.


Asunto(s)
Fagopyrum , Pared Celular , Pectinas
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