Tropomyosin(TM)is the predominant allergenic protein in shrimp,which has induced IgE-mediated food allergy reactions.In this study,Lit v 1 was purified from Penaeus vannamei muscles,which were glyco sylated by pectic ...Tropomyosin(TM)is the predominant allergenic protein in shrimp,which has induced IgE-mediated food allergy reactions.In this study,Lit v 1 was purified from Penaeus vannamei muscles,which were glyco sylated by pectic oligosaccharides.The results showed that di-galacturonic acid(DGA)and galacturonic acid(GA)induced the unfolding of the primary protein structure of TM,and changedα-helical structure,and IgE binding capacity.In addition,compared with TM-sensitized BALB/c mice,GA-modified TM(GA-TM)and DGA-modified TM(DGA-TM)were insufficient to stimulate sensitization,and significantly reduced the hypersecretion of IgE,IgG1,HIS,and IL-4,up-regulated IgG2a and IFN-y levels to improve imbalanced Th1/Th2,Treg/Th17 immunity,and promoted mRNA expression of tight junction proteins.Together,this study confirmed that glycosylation modification alleviated sensitization by altering TM structure,reducing IgE binding allergic inflammatory response,and regulating cytokine immune balance.Overall,these results indicated that glycosylation modification was a promising method for decreasing the allergenic reactivity of allergic proteins.展开更多
Pectin is a natural polysaccharide with a complex structure consisting of linear and branched regions rich in galacturonic acid.The growing interest in orange peel pectin can be attributed to its abundant supply.Accor...Pectin is a natural polysaccharide with a complex structure consisting of linear and branched regions rich in galacturonic acid.The growing interest in orange peel pectin can be attributed to its abundant supply.According to statistics,about 10 million tons of orange peel waste are produced worldwide each year.Traditionally,the extraction and utilization of pectin have focused on its gelling,thickening,and stabilizing properties in food.However,as more and more research teams have found that pectin has good biocompatibility,biodegradability and easy chemical modification,its potential in drug delivery systems,tissue engineering,and wound healing is gradually being explored.This review focuses on orange peel pectin polysaccharides and discusses its traditional and modern extraction techniques,especially the advanced method of subcritical water extraction.This study also outlines the structural modifications of pectin such as methylation and acetylation,and introduces its antioxidant and anticancer biological activities and their emerging roles in the development of advanced biomaterials such as bone tissue engineering and fibre pad dressings.展开更多
The germination process of seeds is influenced by the interplay between two opposing factors,pectin methylesterase(PME)and pectin methylesterase inhibitor(PMEI),which collectively regulate patterns of pectin methylest...The germination process of seeds is influenced by the interplay between two opposing factors,pectin methylesterase(PME)and pectin methylesterase inhibitor(PMEI),which collectively regulate patterns of pectin methylesterification.Despite the recognized importance of pectin methylesterification in seed germination,the specific mechanisms that govern this process remain unclear.In this study,we demonstrated that the overexpression of GhPMEI53is associated with a decrease in PME activity and an increase in pectin methylesterification.This leads to seed cell wall softening,which positively regulates cotton seed germination.AtPMEI19,the homologue in Arabidopsis thaliana,plays a similar role in seed germination to GhPMEI53,indicating a conserved function and mechanism of PMEI in seed germination regulation.Further studies revealed that GhPMEI53 and AtPMEI19 directly contribute to promoting radicle protrusion and seed germination by inducing cell wall softening and reducing mechanical strength.Additionally,the pathways of abscicic acid(ABA)and gibberellin(GA)in the transgenic materials showed significant changes,suggesting that GhPMEI53/AtPMEI19-mediated pectin methylesterification serves as a regulatory signal for the related phytohormones involved in seed germination.In summary,GhPMEI53 and its homologs alter the mechanical properties of cell walls,which influence the mechanical resistance of the endosperm or testa.Moreover,they impact cellular phytohormone pathways(e.g.,ABA and GA)to regulate seed germination.These findings enhance our understanding of pectin methylesterification in cellular morphological dynamics and signaling transduction,and contribute to a more comprehensive understanding of the PME/PMEI gene superfamily in plants.展开更多
The transformation of biomasses from agro-industrial waste can significantly impact the production of green chemicals from sustainable resources.Pectin is a biopolymer present in lignocellulosic biomass as Orange Peel...The transformation of biomasses from agro-industrial waste can significantly impact the production of green chemicals from sustainable resources.Pectin is a biopolymer present in lignocellulosic biomass as Orange Peel Waste(OPW)and has possibilities for making platform compounds such as furfural for sustainable chemistry.In this work,we studied the transformation to furfural of OPW,pectins,and d-galacturonic acid(D-GalA),which is the main component(65 wt%)of pectin.We analyzed pectins with different degrees of esterification(45,60 and 95 DE)in a one-pot hydrolysis reaction system and studied the differences in depolymerization and dehydration of the carbohydrates.The results show that the production of furfural decreases as the DE value increases.Specifically,low DE values favor the formation of furfural since the decarboxylation reaction is favored over deesterification.Interestingly,the furfural concentration is dependent upon the polysaccharide composition of pentoses and uronic acid.The obtained concentrations of furfural(13 and 14 mmol/L),d-xylose(6.2 and 10 mmol/L),and L-arabinose(2.5 and 2.7 mmol/L)remained the same when the galacturonic acid was fed either as a polymer or a monomer under the same reaction conditions(0.01 M SA,90 min and 433 K).OPW is proposed as a feedstock in a biorefinery,in which on a per kg OPW dry basis,90 g of pectin and 15 g of furfural were produced in the most favorable case.We conclude that the co-production of pectin and furfural from OPW is economically feasible.展开更多
Pectin lyase(PMGL)is an industrially important enzyme with widespread applications in the food,paper,and textile industries,owing to its capacity for direct degradation of highly esterified pectin.In this study,PMGL-B...Pectin lyase(PMGL)is an industrially important enzyme with widespread applications in the food,paper,and textile industries,owing to its capacity for direct degradation of highly esterified pectin.In this study,PMGL-Ba derived from Bacillus licheniformis underwent mining and heterologous expression in P.pastoris.Furthermore,diverse strategies,encompassing the optimization of expression cassette components,elevation of gene dosage,and co-expression of chaperone factors,were employed to augment PMGL-Ba production in P.pastoris.The signaling peptide OST1-pre-α-MF-pro and promoter AOX1 were finally selected as expression elements.By overexpressing the transcription factor Hac1p in conjunction with a two-copy PMGL-Ba setup,a strain yielding high PMGL-Ba production was achieved.In shake flask fermentation lasting 144 h,the total protein concentration reached 1.81 g/L,and the enzyme activity reached 1821.36 U/mL.For further scale up production,high-density fermentation transpired in a 5 L fermenter for 72 h.Remarkably,the total protein concentration increased to 12.49 g/L,and the enzyme activity reached an impressive 12668.12 U/mL.The successful heterologous and efficient expression of PMGL-Ba not only furnishes a valuable biological enzyme for industrial applications but also contributes to cost reduction in the utilization of biological enzymes in industrial applications.展开更多
This study demonstrated that Bacillus licheniformis HDYM-03 and Bacillus megaterium HDYM-09, isolated from a liquid sample of fl ax retting pool, were able to produce pectinolytic enzymes using polysaccharides as subs...This study demonstrated that Bacillus licheniformis HDYM-03 and Bacillus megaterium HDYM-09, isolated from a liquid sample of fl ax retting pool, were able to produce pectinolytic enzymes using polysaccharides as substrates. Bacillus megaterium HDYM-09 produced pectin lyase that exhibited the highest activity of 2116.71 ± 11.55 U/mL. Bacillus licheniformis HDYM-03 produced pectate lyase that exhibited the highest activity of 611.21 ± 14.54 U/mL. Based on these fi ndings, we constructed four retting systems to degrade the pectin substance. The results showed that the content of galacturonic acid in the mixed system was 529.21 μg/mL, the content of reducing sugar was 98.14 mg/mL, and the weight loss ratio of cells reached 19.49%, which were signifi cantly higher than those in other systems. The mixed system has more advantages, and the utilization rate of degumming was higher, which further ensured that the degumming can be carried out effi ciently and quickly. The mixed system exhibits feasible applications in the fi ber and textile industry.展开更多
In order to solve the citrus peel resource waste problem protopectinase-overproducing strain CD-01 for pectin production and minimize the drawbacks of chemical extraction of pectin, a was isolated from a pit soil dump...In order to solve the citrus peel resource waste problem protopectinase-overproducing strain CD-01 for pectin production and minimize the drawbacks of chemical extraction of pectin, a was isolated from a pit soil dumped with perished orange in Changde City, Hunan Province of China. The strain CD-01 had the same morphology and 28S rRNA gene sequence （FJ184995） as that of Aspergillus niger （ATCC 64028）. It was thus identified and named as Aspergillus niger CD-01. The fermentation condition was optimized based on L9（34） orthogonal experimental design and the variances analyses. The results show that the optimal condition for producing pectin is as follows： time 36 h, temperature 35 ℃, pH 5, and urea as the nitrogen source. Under this condition, the pectin yield can reach up to 24.5%. This shows a great potential of Aspergillus niger CD-01 in pectin extraction from citrus.展开更多
We studied the effect of two independent variables, the pectin/calcium chloride weight ratio and the overall matrix weight in HPMC/pectin/calcium matrix tablet, on the release of indomethacin. A two-factor 5-level cen...We studied the effect of two independent variables, the pectin/calcium chloride weight ratio and the overall matrix weight in HPMC/pectin/calcium matrix tablet, on the release of indomethacin. A two-factor 5-level central composite experimental design was employed. Responses of the Peppas correlation parameters n and K and the 10% release time （T0.1） were optimized by response surface methodology. Significant effect of the independent variables on the biphasic release parameters, n and K, was observed. N, K and T0.1 were well fitted with the second-order quadratic equations rather than linear equations. Moreover, the mathematic fitting and the response surfaces showed significant cross-interaction between the pectin/calcium chloride ratio and the overall matrix weight. The optimal formulation with larger n, longer T0.1 and smaller K consisted of medium pectin/calcium chloride ratio around 1.0 and medium matrix weight around 200 mg. Validation studies on the optimal formulations showed good predictability of the n, K and T0.1 values with biases within the range of-7.33% and 6.26%. Our results support that central composite design can be used to optimize drug release from HPMC/pectin/calcium matrix tablet with high predictability.展开更多
The comparison was conducted to investigate the higher extraction rate between two methods including alcohol deposition with acid hydrolysis and micro- wave-assistant extraction technique. The experimental results sho...The comparison was conducted to investigate the higher extraction rate between two methods including alcohol deposition with acid hydrolysis and micro- wave-assistant extraction technique. The experimental results showed that the former method led to a better extraction effect. For the method of alcohol deposition with acid hydrolysis, the technique parameters were optimized through I.s （34 ） orthogonal e^periment based on the results of single factor experiments, after investi- gated the effect of solid to liquid ratio, pH, extraction temperature and extraction time on the pectin extraction rate. tersrm technique was employed to extract pectin. The selected parameter was obtained by means On the basis of the optimal technical parmne- of L16 （45） orthogonal experiment after studied the effect of solid to liquid ratio, extraction temperature, microwave treatment period, pH and microwave power on pectin extraction yield. Repetitive examinations of two methods were carried out separately, pectin extraction rate with the fLrst technique was 14.57% and that with the second method was 11.62%. The charac- teristics of the pectin sample prepared by alcohol deposition with acid hydrolysis were further investigated. The research demonstrated that mass percent of pectin was 87.23%. The esterification degree of pectin was 75.66% ,and pectin sample color was from creamy white to pale yellow.展开更多
The flesh of spaghetti squash separates into strands when cooked. The purpose of this paper is to investigate the cause of strand separation （during cooking） by soaking for 24 h at 35 ℃ in solutions with three kind...The flesh of spaghetti squash separates into strands when cooked. The purpose of this paper is to investigate the cause of strand separation （during cooking） by soaking for 24 h at 35 ℃ in solutions with three kinds of pectin extractant. The changes in strand separation, firmness, histological structure and the pectin of flesh during soaking in 0.01 N HCI solution （pH 2.0）, 0.035 M ammonium oxalate solution （pH 4.0） or 2% sodium hexametaphosphate solution （pH 4.0） were investigated. When flesh was soaked in the HCI solution, the separation into strands and removal of calcium and magnesium were greater than that soaked in other pectin extractants. High methoxyl pectin was extracted by soaking in HC1 solution （pH 2.0） due to removal of polyvalent cations. This result shows that high methoxyl pectin glues strands together in the flesh of spaghetti squash. The shape of the cells which constituted strands was round; on the other hand, that of cells surrounded strands was elongated. When cooked in boiling water or soaked at pH 2.0, the shape of the former cells was maintained, but the latter cells, which contributed to adhesion between strands, broke down. Thus, the flesh separated into strands. When flesh was boiled for 15-30 min, pectin degraded and dissolved in the cooking solution; consequently, the flesh separated into strands and also the middle lamella of cell walls of strands separated. However, pectin remaining in strands maintained their crispness.展开更多
AIM: To compare the effectiveness of standard triple, bismuth pectin quadruple and sequential therapies for Helicobacter pylori (H. pylori ) eradication in a randomized, double-blinded, comparative clinical trial in C...AIM: To compare the effectiveness of standard triple, bismuth pectin quadruple and sequential therapies for Helicobacter pylori (H. pylori ) eradication in a randomized, double-blinded, comparative clinical trial in China. METHODS: A total of 215 H. pylori -positive patients were enrolled in the study and randomly allocated into three groups: group A (n = 72) received a 10-d bismuth pectin quadruple therapy (20 mg rabeprazole bid , 1000 mg amoxicillin bid , 100 mg bismuth pectin qid , and 500 mg levofloxacin qd ); group B (n = 72) received the sequential therapy (20 mg omeprazole bid , 1000 mg amoxicillin bid , in 5 d, followed by 20 mg omeprazole bid , 500 mg tinidazole bid , 500 mg clarithromycin bid , for another 5 d); group C (n = 71) received a standard 1-wk triple therapy (20 mg omeprazole bid , 1000 mg amoxicillin bid , 500 mg clarithromycin bid ). After all these treatments, 20 mg omeprazole bid was administrated for 3 wk. H. pylori status was assessed by histology, 13C-urea breath test and rapid urease test at baseline and 4-6 wk after completion of treatment. Ulcer cicatrization was assessed by gastroscopy. χ 2 test (P < 0.05) was used to compare the eradication rates and ulcer cicatrisation rates among the three groups. RESULTS: The eradication rate was 83.33% (60/72) in group A, 88.89% (64/72) in group B, and 80.56% (58/71) in group C. The ulcer cicatrisation rate was 86.44% (51/59) in group A, 90.16% (55/61) in group B, and 84.91% (45/53) in group C. The sequential therapy yielded a higher eradication rate and ulcer cicatrisation rate than the standard triple and bismuth pectin quadruple therapies. Statistically, the eradication rate of group B was significantly different from groups A and C (P < 0.05), but the difference of ulcer cicatrisation rate and side effects was not statistically significant among the three groups (P > 0.05). The three protocols were generally well tolerated. CONCLUSION: The sequential therapy has achieved a significantly higher eradication rate, and is a more suitable first-line alternative protocol for anti-H. pylori infection compared with the standard triple and bismuth pectin quadruple therapies.展开更多
AIM: To discuss the expression of glactin-3 in liver metastasis of colon cancer and its inhibition by modi- fied citrus pectin (MCP) in mice. METHODS: Seventy-five Balb/c mice were randomly di- vided into negative con...AIM: To discuss the expression of glactin-3 in liver metastasis of colon cancer and its inhibition by modi- fied citrus pectin (MCP) in mice. METHODS: Seventy-five Balb/c mice were randomly di- vided into negative control group (n = 15), positive con- trol group (n = 15), low MCP concentration group (n = 15), middle MCP concentration group (n = 15) and high MCP concentration group (n = 15). CT26 colon cancer cells were injected into the subcapsule of mouse spleen in positive control group, low, middle and high MCP concentrations groups, except in negative control, to set up a colon cancer liver metastasis model. The concen- tration of MCP in drinking water was 0.0%, 0.0%, 1.0%, 2.5% and 5.0% (wt/vol), respectively. Liver metastasis of colon cancer was observed after 3 wk. Enzyme-linked immunosorbent assay (ELISA) was used to detect the concentration of galectin-3 in serum. Expression of ga- lectin-3 in liver metastasis was detected by immunohis- tochemistry. RESULTS: Except for the negative group, the percent- age of liver metastasis in the other 4 groups was 100%, 80%, 73.3% and 60%, respectively. The number of liver metastases in high MCP concentration group was significantly less than that in positive control group (P = 0.008). Except for the negative group, the median volume of implanted spleen tumor in the other 4 groups was 1.51 cm3, 0.93 cm3, 0.77 cm3 and 0.70 cm3, respec- tively. The volume of implanted tumor in middle and high MCP concentration groups was significantly smaller than that in positive control group (P = 0.019; P = 0.003). The concentration of serum galectin-3 in positive control and MCP treatment groups was significantly higher than that in the negative control group. However, there was no significant difference between them. Except for the negative control group, the expression of galectin-3 in liver metastases of the other 4 groups showed no sig- nificant difference. CONCLUSION: Expression of galetin-3 increases sig- nificantly in liver metastasis of colon cancer, which can be effectively inhibited by MCP.展开更多
Modified pectin cross-linked with adipic acid, was synthesized and used for heavy metal removal from wastewater. SEM and FTIR were used to investigate its structure and morphology. The modified pectin had a rough, por...Modified pectin cross-linked with adipic acid, was synthesized and used for heavy metal removal from wastewater. SEM and FTIR were used to investigate its structure and morphology. The modified pectin had a rough, porous phase covered with carboxy groups, resulting a high adsorption capacity. And at the room temperature, the saturated loading capacity for Pb^2＋, Cu^2＋ and Zn^2＋ reached 1.82 retool/g, 1.794 mmol/g and 0.964 retool/g, respectively. The results proved its potential application to remove of the heavy metal.展开更多
The aim of this study was to investigate the effect of high-pressure homogenization on the droplet size and physical stability of different formulations of pectin–zein stabilized rice bran oil emulsions. The obtained...The aim of this study was to investigate the effect of high-pressure homogenization on the droplet size and physical stability of different formulations of pectin–zein stabilized rice bran oil emulsions. The obtained emulsions, both before and after passing through highpressure homogenizer, were subjected to stability test under environmental stress conditions,that is, temperature cycling at 4 °C/40 °C for 6 cycles and centrifugal test at 3000 rpm for 10 min. Applying high-pressure homogenization after mechanical homogenization caused only a small additional decrease in emulsion droplet size. The droplet size of emulsions was influenced by the type of pectin used;emulsions using high methoxy pectin(HMP) were smaller than that using low methoxy pectin(LMP). This is due to a greater emulsifying property of HMP than LMP. The emulsions stabilized by HMP–zein showed good physical stability with lower percent creaming index than those using LMP, both before and after passing through high-pressure homogenizer. The stability of emulsions after passing through high-pressure homogenizer was slightly higher when using higher zein concentration, resulting from stronger pectin–zein complexes that could rearrange and adsorb onto the emulsion droplets.展开更多
Novel oral microbeads were developed based on a biopolymer–drug conjugate of doxorubicin(DOX) conjugated with thiolated pectin via reducible disulfide bonds. The microbeads were fabricated by ionotropic gelation with...Novel oral microbeads were developed based on a biopolymer–drug conjugate of doxorubicin(DOX) conjugated with thiolated pectin via reducible disulfide bonds. The microbeads were fabricated by ionotropic gelation with cations such as Al3+, Ca2+ and Zn2+. The results showed that using zinc acetate can produce the strongest microbeads with spherical shape.However, the microbeads prepared from thiolated pectin–DOX conjugate were very soft and irregular in shape. To produce more spherical microbeads with suitable strength, the native pectin was then added to the formulations. The particle size of the microbeads ranged from 0.87 to 1.14 mm. The morphology of the microbeads was characterized by optical and scanning electron microscopy. DOX was still in crystalline form when used in preparing the microbeads, as confirmed by powder X-ray diffractometry. Drug release profiles showed that the microbeads containing thiolated pectin–DOX conjugate exhibited reduction-responsive character;in reducing environments, the thiolated pectin–DOX conjugate could uncouple resulting from a cleavage of the disulfide linkers and consequently release the DOX. The best-fit release kinetics of the microbeads containing thiolated pectin–DOX conjugate, in the medium without reducing agent, fit the Korsmeyer–Peppas model while those in the medium with reducing agent fit a zero-order release model. These results suggested that the microbeads containing thiolated pectin–DOX conjugate may be a promising platform for cancer-targeted delivery of DOX, exploiting the reducing environment typically found in tumors.展开更多
Calcium-alginate pectin entrapped bitter gourd peroxidase （BGP） has been employed for the treatment of disperse dyes： Disperse Brown 1 （DB 1） and Disperse Red 17 （DR 17）. Peroxidase alone was unable to decolori...Calcium-alginate pectin entrapped bitter gourd peroxidase （BGP） has been employed for the treatment of disperse dyes： Disperse Brown 1 （DB 1） and Disperse Red 17 （DR 17）. Peroxidase alone was unable to decolorize DR 17 and DB 1. However, the investigated dyes were decolorized maximally by BGP in the presence of 0.2 mmol/L redox mediator, violuric acid （VA）. A slow decrease in percent decolorization was observed when VA concentration was higher than 0.2 mmol/L which could likely be due to the high reactivity of its aminoxyl radical （ N–O . ） intermediate, that might undergo chemical reactions with aromatic amino acid side chains of the enzyme thereby inactivating it. Maximum decolorization of the dyes was observed at pH 3.0 and 40°C within 2 hr of incubation. Immobilized peroxidase decolorized 98% DR 17 and 71% DB 1 using 35 U of BGP in batch process in 90 min. Immobilized enzyme decolorized 85% DR 17 and 51% DB 1 whereas soluble enzyme decolorized DR 17 to 48% and DB 1 to 30% at 60°C. UV-visible spectral analysis was used to evaluate the degradation of these dyes and their toxicity was tested by Allium cepa test. The generally observed higher stability of the bioaffinity bound enzymes against various forms of inactivation may be related to the specific and strong binding of enzyme with bioaffinity support which prevents the unfolding/denaturation of enzyme. Thus entrapped peroxidase was found to be effective in the decolorization of the investigated dyes.展开更多
Background Pectin is a heteropolysaccharide that acts as an intestinal immunomodulator,promoting intestinal development and regulating intestinal flora in the gut.However,the relevant mechanisms remain obscure.In this...Background Pectin is a heteropolysaccharide that acts as an intestinal immunomodulator,promoting intestinal development and regulating intestinal flora in the gut.However,the relevant mechanisms remain obscure.In this study,pigs were fed a corn-soybean meal-based diet supplemented with either 5%microcrystalline cellulose(MCC)or 5%pectin for 3 weeks,to investigate the metabolites and anti-inflammatory properties of the jejunum.Result The results showed that dietary pectin supplementation improved intestinal integrity(Claudin-1,Occludin)and inflammatory response[interleukin(IL)-10],and the expression of proinflammatory cytokines(IL-1β,IL-6,IL-8,TNF-α)was down-regulated in the jejunum.Moreover,pectin supplementation altered the jejunal microbiome and tryptophan-related metabolites in piglets.Pectin specifically increased the abundance of Lactococcus,Enterococcus,and the microbiota-derived metabolites(skatole(ST),3-indoleacetic acid(IAA),3-indolepropionic acid(IPA),5-hydroxyindole-3-acetic acid(HIAA),and tryptamine(Tpm)),which activated the aryl hydrocarbon receptor(AhR)pathway.AhR activation modulates IL-22 and its downstream pathways.Correlation analysis revealed the potential relationship between metabolites and intestinal morphology,intestinal gene expression,and cytokine levels.Conclusion In conclusion,these results indicated that pectin inhibits the inflammatory response by enhancing the AhR-IL22-signal transducer and activator of transcription 3 signaling pathway,which is activated through tryptophan metabolites.展开更多
The gastrointestinal tract of livestock and poultry is prone to challenge by feedborne antigens,pathogens,and other stress factors in the farm environment.Excessive physiological inflammation and oxidative stress that...The gastrointestinal tract of livestock and poultry is prone to challenge by feedborne antigens,pathogens,and other stress factors in the farm environment.Excessive physiological inflammation and oxidative stress that arises firstly disrupts the intestinal epithelial barrier followed by other components of the gastrointestinal tract.In the present review,the interrelationship between intestinal barrier inflammation and oxidative stress that contributes to the pathogenesis of inflammatory bowel disease was described.Further,the role of naturally existing immunomodulatory nutrients such as the omega-3 polyunsaturated fatty acids,citrus pectin,and milk-derived exosomes in preventing intestinal barrier inflammation was discussed.Based on the existing evidence,the possible molecular mechanism of these bioactive nutrients in the intestinal barrier was outlined for application in animal diets.展开更多
基金supported by the National Natural Science Fund(31601395)Central Guidance on Local Science and Technology Development Fund of Guizhou Province([2023]016)+1 种基金China National Center for Food Safety Risk Assessment(2018K01-20171211)Lueyang Black-Bone Chicken Industry Development Research Institute(WJYJY-2021-9)。
文摘Tropomyosin(TM)is the predominant allergenic protein in shrimp,which has induced IgE-mediated food allergy reactions.In this study,Lit v 1 was purified from Penaeus vannamei muscles,which were glyco sylated by pectic oligosaccharides.The results showed that di-galacturonic acid(DGA)and galacturonic acid(GA)induced the unfolding of the primary protein structure of TM,and changedα-helical structure,and IgE binding capacity.In addition,compared with TM-sensitized BALB/c mice,GA-modified TM(GA-TM)and DGA-modified TM(DGA-TM)were insufficient to stimulate sensitization,and significantly reduced the hypersecretion of IgE,IgG1,HIS,and IL-4,up-regulated IgG2a and IFN-y levels to improve imbalanced Th1/Th2,Treg/Th17 immunity,and promoted mRNA expression of tight junction proteins.Together,this study confirmed that glycosylation modification alleviated sensitization by altering TM structure,reducing IgE binding allergic inflammatory response,and regulating cytokine immune balance.Overall,these results indicated that glycosylation modification was a promising method for decreasing the allergenic reactivity of allergic proteins.
文摘Pectin is a natural polysaccharide with a complex structure consisting of linear and branched regions rich in galacturonic acid.The growing interest in orange peel pectin can be attributed to its abundant supply.According to statistics,about 10 million tons of orange peel waste are produced worldwide each year.Traditionally,the extraction and utilization of pectin have focused on its gelling,thickening,and stabilizing properties in food.However,as more and more research teams have found that pectin has good biocompatibility,biodegradability and easy chemical modification,its potential in drug delivery systems,tissue engineering,and wound healing is gradually being explored.This review focuses on orange peel pectin polysaccharides and discusses its traditional and modern extraction techniques,especially the advanced method of subcritical water extraction.This study also outlines the structural modifications of pectin such as methylation and acetylation,and introduces its antioxidant and anticancer biological activities and their emerging roles in the development of advanced biomaterials such as bone tissue engineering and fibre pad dressings.
基金funded by the National Natural Science Foundation of China(32072022)the Nanfan Special Project,CAAS(YBXM07)the Hainan Yazhou Bay Seed Laboratory,China(B23CJ0208)。
文摘The germination process of seeds is influenced by the interplay between two opposing factors,pectin methylesterase(PME)and pectin methylesterase inhibitor(PMEI),which collectively regulate patterns of pectin methylesterification.Despite the recognized importance of pectin methylesterification in seed germination,the specific mechanisms that govern this process remain unclear.In this study,we demonstrated that the overexpression of GhPMEI53is associated with a decrease in PME activity and an increase in pectin methylesterification.This leads to seed cell wall softening,which positively regulates cotton seed germination.AtPMEI19,the homologue in Arabidopsis thaliana,plays a similar role in seed germination to GhPMEI53,indicating a conserved function and mechanism of PMEI in seed germination regulation.Further studies revealed that GhPMEI53 and AtPMEI19 directly contribute to promoting radicle protrusion and seed germination by inducing cell wall softening and reducing mechanical strength.Additionally,the pathways of abscicic acid(ABA)and gibberellin(GA)in the transgenic materials showed significant changes,suggesting that GhPMEI53/AtPMEI19-mediated pectin methylesterification serves as a regulatory signal for the related phytohormones involved in seed germination.In summary,GhPMEI53 and its homologs alter the mechanical properties of cell walls,which influence the mechanical resistance of the endosperm or testa.Moreover,they impact cellular phytohormone pathways(e.g.,ABA and GA)to regulate seed germination.These findings enhance our understanding of pectin methylesterification in cellular morphological dynamics and signaling transduction,and contribute to a more comprehensive understanding of the PME/PMEI gene superfamily in plants.
基金supported by the project:“Obtención de biocombustibles y compuestos químicos de alto valor agregado a partir de biomasas de desecho ricas en pectina”,CONAHCYT agreement:CB 255527-2016the Fellowship with reference number:654271 from the Mexican Council for Science and Technology,CONAHCYT was assigned to Eva Estela Rivera Cedillo as PhD student.
文摘The transformation of biomasses from agro-industrial waste can significantly impact the production of green chemicals from sustainable resources.Pectin is a biopolymer present in lignocellulosic biomass as Orange Peel Waste(OPW)and has possibilities for making platform compounds such as furfural for sustainable chemistry.In this work,we studied the transformation to furfural of OPW,pectins,and d-galacturonic acid(D-GalA),which is the main component(65 wt%)of pectin.We analyzed pectins with different degrees of esterification(45,60 and 95 DE)in a one-pot hydrolysis reaction system and studied the differences in depolymerization and dehydration of the carbohydrates.The results show that the production of furfural decreases as the DE value increases.Specifically,low DE values favor the formation of furfural since the decarboxylation reaction is favored over deesterification.Interestingly,the furfural concentration is dependent upon the polysaccharide composition of pentoses and uronic acid.The obtained concentrations of furfural(13 and 14 mmol/L),d-xylose(6.2 and 10 mmol/L),and L-arabinose(2.5 and 2.7 mmol/L)remained the same when the galacturonic acid was fed either as a polymer or a monomer under the same reaction conditions(0.01 M SA,90 min and 433 K).OPW is proposed as a feedstock in a biorefinery,in which on a per kg OPW dry basis,90 g of pectin and 15 g of furfural were produced in the most favorable case.We conclude that the co-production of pectin and furfural from OPW is economically feasible.
基金supported by the National Key R&D Program of China(NO.2021YFC2100400).
文摘Pectin lyase(PMGL)is an industrially important enzyme with widespread applications in the food,paper,and textile industries,owing to its capacity for direct degradation of highly esterified pectin.In this study,PMGL-Ba derived from Bacillus licheniformis underwent mining and heterologous expression in P.pastoris.Furthermore,diverse strategies,encompassing the optimization of expression cassette components,elevation of gene dosage,and co-expression of chaperone factors,were employed to augment PMGL-Ba production in P.pastoris.The signaling peptide OST1-pre-α-MF-pro and promoter AOX1 were finally selected as expression elements.By overexpressing the transcription factor Hac1p in conjunction with a two-copy PMGL-Ba setup,a strain yielding high PMGL-Ba production was achieved.In shake flask fermentation lasting 144 h,the total protein concentration reached 1.81 g/L,and the enzyme activity reached 1821.36 U/mL.For further scale up production,high-density fermentation transpired in a 5 L fermenter for 72 h.Remarkably,the total protein concentration increased to 12.49 g/L,and the enzyme activity reached an impressive 12668.12 U/mL.The successful heterologous and efficient expression of PMGL-Ba not only furnishes a valuable biological enzyme for industrial applications but also contributes to cost reduction in the utilization of biological enzymes in industrial applications.
基金supported by the National Natural Science Foundation of China (Nos. 31270534, 31770538)the National Natural Science Youth Foundation of China (No. 31300355)the Post-Doctorate Foundation of Heilongjiang Province (No. LBH-Z15214)
文摘This study demonstrated that Bacillus licheniformis HDYM-03 and Bacillus megaterium HDYM-09, isolated from a liquid sample of fl ax retting pool, were able to produce pectinolytic enzymes using polysaccharides as substrates. Bacillus megaterium HDYM-09 produced pectin lyase that exhibited the highest activity of 2116.71 ± 11.55 U/mL. Bacillus licheniformis HDYM-03 produced pectate lyase that exhibited the highest activity of 611.21 ± 14.54 U/mL. Based on these fi ndings, we constructed four retting systems to degrade the pectin substance. The results showed that the content of galacturonic acid in the mixed system was 529.21 μg/mL, the content of reducing sugar was 98.14 mg/mL, and the weight loss ratio of cells reached 19.49%, which were signifi cantly higher than those in other systems. The mixed system has more advantages, and the utilization rate of degumming was higher, which further ensured that the degumming can be carried out effi ciently and quickly. The mixed system exhibits feasible applications in the fi ber and textile industry.
基金Projects(50621063, 50674101) supported by the National Natural Science Foundation of China
文摘In order to solve the citrus peel resource waste problem protopectinase-overproducing strain CD-01 for pectin production and minimize the drawbacks of chemical extraction of pectin, a was isolated from a pit soil dumped with perished orange in Changde City, Hunan Province of China. The strain CD-01 had the same morphology and 28S rRNA gene sequence （FJ184995） as that of Aspergillus niger （ATCC 64028）. It was thus identified and named as Aspergillus niger CD-01. The fermentation condition was optimized based on L9（34） orthogonal experimental design and the variances analyses. The results show that the optimal condition for producing pectin is as follows： time 36 h, temperature 35 ℃, pH 5, and urea as the nitrogen source. Under this condition, the pectin yield can reach up to 24.5%. This shows a great potential of Aspergillus niger CD-01 in pectin extraction from citrus.
基金Shanghai Municipal Committee of Sciencc and Tcchnology (Grant No.024319114).
文摘We studied the effect of two independent variables, the pectin/calcium chloride weight ratio and the overall matrix weight in HPMC/pectin/calcium matrix tablet, on the release of indomethacin. A two-factor 5-level central composite experimental design was employed. Responses of the Peppas correlation parameters n and K and the 10% release time （T0.1） were optimized by response surface methodology. Significant effect of the independent variables on the biphasic release parameters, n and K, was observed. N, K and T0.1 were well fitted with the second-order quadratic equations rather than linear equations. Moreover, the mathematic fitting and the response surfaces showed significant cross-interaction between the pectin/calcium chloride ratio and the overall matrix weight. The optimal formulation with larger n, longer T0.1 and smaller K consisted of medium pectin/calcium chloride ratio around 1.0 and medium matrix weight around 200 mg. Validation studies on the optimal formulations showed good predictability of the n, K and T0.1 values with biases within the range of-7.33% and 6.26%. Our results support that central composite design can be used to optimize drug release from HPMC/pectin/calcium matrix tablet with high predictability.
文摘The comparison was conducted to investigate the higher extraction rate between two methods including alcohol deposition with acid hydrolysis and micro- wave-assistant extraction technique. The experimental results showed that the former method led to a better extraction effect. For the method of alcohol deposition with acid hydrolysis, the technique parameters were optimized through I.s （34 ） orthogonal e^periment based on the results of single factor experiments, after investi- gated the effect of solid to liquid ratio, pH, extraction temperature and extraction time on the pectin extraction rate. tersrm technique was employed to extract pectin. The selected parameter was obtained by means On the basis of the optimal technical parmne- of L16 （45） orthogonal experiment after studied the effect of solid to liquid ratio, extraction temperature, microwave treatment period, pH and microwave power on pectin extraction yield. Repetitive examinations of two methods were carried out separately, pectin extraction rate with the fLrst technique was 14.57% and that with the second method was 11.62%. The charac- teristics of the pectin sample prepared by alcohol deposition with acid hydrolysis were further investigated. The research demonstrated that mass percent of pectin was 87.23%. The esterification degree of pectin was 75.66% ,and pectin sample color was from creamy white to pale yellow.
文摘The flesh of spaghetti squash separates into strands when cooked. The purpose of this paper is to investigate the cause of strand separation （during cooking） by soaking for 24 h at 35 ℃ in solutions with three kinds of pectin extractant. The changes in strand separation, firmness, histological structure and the pectin of flesh during soaking in 0.01 N HCI solution （pH 2.0）, 0.035 M ammonium oxalate solution （pH 4.0） or 2% sodium hexametaphosphate solution （pH 4.0） were investigated. When flesh was soaked in the HCI solution, the separation into strands and removal of calcium and magnesium were greater than that soaked in other pectin extractants. High methoxyl pectin was extracted by soaking in HC1 solution （pH 2.0） due to removal of polyvalent cations. This result shows that high methoxyl pectin glues strands together in the flesh of spaghetti squash. The shape of the cells which constituted strands was round; on the other hand, that of cells surrounded strands was elongated. When cooked in boiling water or soaked at pH 2.0, the shape of the former cells was maintained, but the latter cells, which contributed to adhesion between strands, broke down. Thus, the flesh separated into strands. When flesh was boiled for 15-30 min, pectin degraded and dissolved in the cooking solution; consequently, the flesh separated into strands and also the middle lamella of cell walls of strands separated. However, pectin remaining in strands maintained their crispness.
文摘AIM: To compare the effectiveness of standard triple, bismuth pectin quadruple and sequential therapies for Helicobacter pylori (H. pylori ) eradication in a randomized, double-blinded, comparative clinical trial in China. METHODS: A total of 215 H. pylori -positive patients were enrolled in the study and randomly allocated into three groups: group A (n = 72) received a 10-d bismuth pectin quadruple therapy (20 mg rabeprazole bid , 1000 mg amoxicillin bid , 100 mg bismuth pectin qid , and 500 mg levofloxacin qd ); group B (n = 72) received the sequential therapy (20 mg omeprazole bid , 1000 mg amoxicillin bid , in 5 d, followed by 20 mg omeprazole bid , 500 mg tinidazole bid , 500 mg clarithromycin bid , for another 5 d); group C (n = 71) received a standard 1-wk triple therapy (20 mg omeprazole bid , 1000 mg amoxicillin bid , 500 mg clarithromycin bid ). After all these treatments, 20 mg omeprazole bid was administrated for 3 wk. H. pylori status was assessed by histology, 13C-urea breath test and rapid urease test at baseline and 4-6 wk after completion of treatment. Ulcer cicatrization was assessed by gastroscopy. χ 2 test (P < 0.05) was used to compare the eradication rates and ulcer cicatrisation rates among the three groups. RESULTS: The eradication rate was 83.33% (60/72) in group A, 88.89% (64/72) in group B, and 80.56% (58/71) in group C. The ulcer cicatrisation rate was 86.44% (51/59) in group A, 90.16% (55/61) in group B, and 84.91% (45/53) in group C. The sequential therapy yielded a higher eradication rate and ulcer cicatrisation rate than the standard triple and bismuth pectin quadruple therapies. Statistically, the eradication rate of group B was significantly different from groups A and C (P < 0.05), but the difference of ulcer cicatrisation rate and side effects was not statistically significant among the three groups (P > 0.05). The three protocols were generally well tolerated. CONCLUSION: The sequential therapy has achieved a significantly higher eradication rate, and is a more suitable first-line alternative protocol for anti-H. pylori infection compared with the standard triple and bismuth pectin quadruple therapies.
文摘AIM: To discuss the expression of glactin-3 in liver metastasis of colon cancer and its inhibition by modi- fied citrus pectin (MCP) in mice. METHODS: Seventy-five Balb/c mice were randomly di- vided into negative control group (n = 15), positive con- trol group (n = 15), low MCP concentration group (n = 15), middle MCP concentration group (n = 15) and high MCP concentration group (n = 15). CT26 colon cancer cells were injected into the subcapsule of mouse spleen in positive control group, low, middle and high MCP concentrations groups, except in negative control, to set up a colon cancer liver metastasis model. The concen- tration of MCP in drinking water was 0.0%, 0.0%, 1.0%, 2.5% and 5.0% (wt/vol), respectively. Liver metastasis of colon cancer was observed after 3 wk. Enzyme-linked immunosorbent assay (ELISA) was used to detect the concentration of galectin-3 in serum. Expression of ga- lectin-3 in liver metastasis was detected by immunohis- tochemistry. RESULTS: Except for the negative group, the percent- age of liver metastasis in the other 4 groups was 100%, 80%, 73.3% and 60%, respectively. The number of liver metastases in high MCP concentration group was significantly less than that in positive control group (P = 0.008). Except for the negative group, the median volume of implanted spleen tumor in the other 4 groups was 1.51 cm3, 0.93 cm3, 0.77 cm3 and 0.70 cm3, respec- tively. The volume of implanted tumor in middle and high MCP concentration groups was significantly smaller than that in positive control group (P = 0.019; P = 0.003). The concentration of serum galectin-3 in positive control and MCP treatment groups was significantly higher than that in the negative control group. However, there was no significant difference between them. Except for the negative control group, the expression of galectin-3 in liver metastases of the other 4 groups showed no sig- nificant difference. CONCLUSION: Expression of galetin-3 increases sig- nificantly in liver metastasis of colon cancer, which can be effectively inhibited by MCP.
文摘Modified pectin cross-linked with adipic acid, was synthesized and used for heavy metal removal from wastewater. SEM and FTIR were used to investigate its structure and morphology. The modified pectin had a rough, porous phase covered with carboxy groups, resulting a high adsorption capacity. And at the room temperature, the saturated loading capacity for Pb^2＋, Cu^2＋ and Zn^2＋ reached 1.82 retool/g, 1.794 mmol/g and 0.964 retool/g, respectively. The results proved its potential application to remove of the heavy metal.
基金financially supported by the Research and Development Institute, Silpakorn University
文摘The aim of this study was to investigate the effect of high-pressure homogenization on the droplet size and physical stability of different formulations of pectin–zein stabilized rice bran oil emulsions. The obtained emulsions, both before and after passing through highpressure homogenizer, were subjected to stability test under environmental stress conditions,that is, temperature cycling at 4 °C/40 °C for 6 cycles and centrifugal test at 3000 rpm for 10 min. Applying high-pressure homogenization after mechanical homogenization caused only a small additional decrease in emulsion droplet size. The droplet size of emulsions was influenced by the type of pectin used;emulsions using high methoxy pectin(HMP) were smaller than that using low methoxy pectin(LMP). This is due to a greater emulsifying property of HMP than LMP. The emulsions stabilized by HMP–zein showed good physical stability with lower percent creaming index than those using LMP, both before and after passing through high-pressure homogenizer. The stability of emulsions after passing through high-pressure homogenizer was slightly higher when using higher zein concentration, resulting from stronger pectin–zein complexes that could rearrange and adsorb onto the emulsion droplets.
文摘Novel oral microbeads were developed based on a biopolymer–drug conjugate of doxorubicin(DOX) conjugated with thiolated pectin via reducible disulfide bonds. The microbeads were fabricated by ionotropic gelation with cations such as Al3+, Ca2+ and Zn2+. The results showed that using zinc acetate can produce the strongest microbeads with spherical shape.However, the microbeads prepared from thiolated pectin–DOX conjugate were very soft and irregular in shape. To produce more spherical microbeads with suitable strength, the native pectin was then added to the formulations. The particle size of the microbeads ranged from 0.87 to 1.14 mm. The morphology of the microbeads was characterized by optical and scanning electron microscopy. DOX was still in crystalline form when used in preparing the microbeads, as confirmed by powder X-ray diffractometry. Drug release profiles showed that the microbeads containing thiolated pectin–DOX conjugate exhibited reduction-responsive character;in reducing environments, the thiolated pectin–DOX conjugate could uncouple resulting from a cleavage of the disulfide linkers and consequently release the DOX. The best-fit release kinetics of the microbeads containing thiolated pectin–DOX conjugate, in the medium without reducing agent, fit the Korsmeyer–Peppas model while those in the medium with reducing agent fit a zero-order release model. These results suggested that the microbeads containing thiolated pectin–DOX conjugate may be a promising platform for cancer-targeted delivery of DOX, exploiting the reducing environment typically found in tumors.
基金Aligarh Muslim University, Aligarh is gratefully ac knowledged for providing University Grants Commission, New Delhi, sponsored fellowship to one of us (Rukhsana Satar)
文摘Calcium-alginate pectin entrapped bitter gourd peroxidase （BGP） has been employed for the treatment of disperse dyes： Disperse Brown 1 （DB 1） and Disperse Red 17 （DR 17）. Peroxidase alone was unable to decolorize DR 17 and DB 1. However, the investigated dyes were decolorized maximally by BGP in the presence of 0.2 mmol/L redox mediator, violuric acid （VA）. A slow decrease in percent decolorization was observed when VA concentration was higher than 0.2 mmol/L which could likely be due to the high reactivity of its aminoxyl radical （ N–O . ） intermediate, that might undergo chemical reactions with aromatic amino acid side chains of the enzyme thereby inactivating it. Maximum decolorization of the dyes was observed at pH 3.0 and 40°C within 2 hr of incubation. Immobilized peroxidase decolorized 98% DR 17 and 71% DB 1 using 35 U of BGP in batch process in 90 min. Immobilized enzyme decolorized 85% DR 17 and 51% DB 1 whereas soluble enzyme decolorized DR 17 to 48% and DB 1 to 30% at 60°C. UV-visible spectral analysis was used to evaluate the degradation of these dyes and their toxicity was tested by Allium cepa test. The generally observed higher stability of the bioaffinity bound enzymes against various forms of inactivation may be related to the specific and strong binding of enzyme with bioaffinity support which prevents the unfolding/denaturation of enzyme. Thus entrapped peroxidase was found to be effective in the decolorization of the investigated dyes.
基金supported by National Natural Science Foundation of China(NSFC)(31802072)China Scholarship Council(CSC NO.202103250006)+1 种基金the Central Public-interest Scientific Institution Basal Research Fund(No.Y2022GH02&PJ01618301)State Key Laboratory of Animal Nutrition(2004DA125184G2102)。
文摘Background Pectin is a heteropolysaccharide that acts as an intestinal immunomodulator,promoting intestinal development and regulating intestinal flora in the gut.However,the relevant mechanisms remain obscure.In this study,pigs were fed a corn-soybean meal-based diet supplemented with either 5%microcrystalline cellulose(MCC)or 5%pectin for 3 weeks,to investigate the metabolites and anti-inflammatory properties of the jejunum.Result The results showed that dietary pectin supplementation improved intestinal integrity(Claudin-1,Occludin)and inflammatory response[interleukin(IL)-10],and the expression of proinflammatory cytokines(IL-1β,IL-6,IL-8,TNF-α)was down-regulated in the jejunum.Moreover,pectin supplementation altered the jejunal microbiome and tryptophan-related metabolites in piglets.Pectin specifically increased the abundance of Lactococcus,Enterococcus,and the microbiota-derived metabolites(skatole(ST),3-indoleacetic acid(IAA),3-indolepropionic acid(IPA),5-hydroxyindole-3-acetic acid(HIAA),and tryptamine(Tpm)),which activated the aryl hydrocarbon receptor(AhR)pathway.AhR activation modulates IL-22 and its downstream pathways.Correlation analysis revealed the potential relationship between metabolites and intestinal morphology,intestinal gene expression,and cytokine levels.Conclusion In conclusion,these results indicated that pectin inhibits the inflammatory response by enhancing the AhR-IL22-signal transducer and activator of transcription 3 signaling pathway,which is activated through tryptophan metabolites.
基金a European Joint Doctorate Degree programme in Molecular Animal Nutrition(MANNA)between University of Milan(Italy)and University of Veterinary Medicine and Pharmacy in Kosice(Slovakia)funding from the European Union’s Horizon 2020 programme under the Marie Slodowska-Curie Grant agreement No 765423.
文摘The gastrointestinal tract of livestock and poultry is prone to challenge by feedborne antigens,pathogens,and other stress factors in the farm environment.Excessive physiological inflammation and oxidative stress that arises firstly disrupts the intestinal epithelial barrier followed by other components of the gastrointestinal tract.In the present review,the interrelationship between intestinal barrier inflammation and oxidative stress that contributes to the pathogenesis of inflammatory bowel disease was described.Further,the role of naturally existing immunomodulatory nutrients such as the omega-3 polyunsaturated fatty acids,citrus pectin,and milk-derived exosomes in preventing intestinal barrier inflammation was discussed.Based on the existing evidence,the possible molecular mechanism of these bioactive nutrients in the intestinal barrier was outlined for application in animal diets.
