Pub Date : 2025-02-01DOI: 10.1016/j.carres.2024.109351
Devika Sajeev , Aparna Rajesh , R. Nethish Kumaar , D. Aswin , Rangasamy Jayakumar , Sreeja C. Nair
Chitosan is a natural polymer that can degrade in the environment and support green chemistry. It displays superior biocompatibility, easy access, and easy modification due to the reactive amino groups to transform or improve the physical and chemical properties. Chitosan can be chemically modified to enhance its properties, such as water solubility and biological activity. Modified chitosan is the most effective functional biomaterial that can be used to deliver the drugs to the targeted site. With diverse and versatile characteristics, it can be fabricated into various drug delivery systems such as membranes, beads, fibers, microparticles, composites, and scaffolds, for different drug delivery methods. Integrating nanotechnology with modified chitosan enhanced the delivery attributes of antibacterial, antifungal, antiviral, anticancer, anti-inflammatory, protein/peptides, and nucleic acids for intended use toward desired therapeutic outcomes. The review brings out an overview of the research regarding drug delivery systems utilizing modifying chitosan detailing the properties, functionality, and applications.
{"title":"Chemically modified chitosan as a functional biomaterial for drug delivery system","authors":"Devika Sajeev , Aparna Rajesh , R. Nethish Kumaar , D. Aswin , Rangasamy Jayakumar , Sreeja C. Nair","doi":"10.1016/j.carres.2024.109351","DOIUrl":"10.1016/j.carres.2024.109351","url":null,"abstract":"<div><div>Chitosan is a natural polymer that can degrade in the environment and support green chemistry. It displays superior biocompatibility, easy access, and easy modification due to the reactive amino groups to transform or improve the physical and chemical properties. Chitosan can be chemically modified to enhance its properties, such as water solubility and biological activity. Modified chitosan is the most effective functional biomaterial that can be used to deliver the drugs to the targeted site. With diverse and versatile characteristics, it can be fabricated into various drug delivery systems such as membranes, beads, fibers, microparticles, composites, and scaffolds, for different drug delivery methods. Integrating nanotechnology with modified chitosan enhanced the delivery attributes of antibacterial, antifungal, antiviral, anticancer, anti-inflammatory, protein/peptides, and nucleic acids for intended use toward desired therapeutic outcomes. The review brings out an overview of the research regarding drug delivery systems utilizing modifying chitosan detailing the properties, functionality, and applications.</div></div>","PeriodicalId":9415,"journal":{"name":"Carbohydrate Research","volume":"548 ","pages":"Article 109351"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142821934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We investigated the transglycosylation reaction of two types of oligosaccharide acceptors, i.e., β-cyclodextrin (CD) derivatives 1 and 2 conjugated with multiple glucose (Glc) units, catalyzed by endo-β-N-acetyl-glucosaminidase from Mucor hiemalis (Endo-M) using the oligosaccharide donor sialoglycopeptide (SGP). The acceptor specificity of the enzyme transglycosylation of 1 and 2 having seven Glc moieties within small nanoscale spatial regions on the β-CDs was investigated on the basis of the effect of the molar ratios of SGP to acceptors 1 or 2 with different spatial configurations on the transglycosylation behavior. The formation of the corresponding CD-based oligosaccharide clusters from Endo-M was also evaluated.
{"title":"Transglycosylation behavior of Mucor hiemalis endo-β-N-acetylglucosaminidase to β-cyclodextrin derivatives with multivalent glucose moieties for synthesizing cyclodextrin-based oligosaccharide clusters","authors":"Yusuke Tomabechi , Yoshiki Oda , Kenji Yamamoto , Takashi Yamanoi","doi":"10.1016/j.carres.2024.109352","DOIUrl":"10.1016/j.carres.2024.109352","url":null,"abstract":"<div><div>We investigated the transglycosylation reaction of two types of oligosaccharide acceptors, i.e., β-cyclodextrin (CD) derivatives <strong>1</strong> and <strong>2</strong> conjugated with multiple glucose (Glc) units, catalyzed by endo-β-<em>N</em>-acetyl-glucosaminidase from <em>Mucor hiemalis</em> (Endo-M) using the oligosaccharide donor sialoglycopeptide (SGP). The acceptor specificity of the enzyme transglycosylation of <strong>1</strong> and <strong>2</strong> having seven Glc moieties within small nanoscale spatial regions on the β-CDs was investigated on the basis of the effect of the molar ratios of SGP to acceptors <strong>1</strong> or <strong>2</strong> with different spatial configurations on the transglycosylation behavior. The formation of the corresponding CD-based oligosaccharide clusters from Endo-M was also evaluated.</div></div>","PeriodicalId":9415,"journal":{"name":"Carbohydrate Research","volume":"548 ","pages":"Article 109352"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142869398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.carres.2025.109411
Govind P. Singh , Flinta E.D. Wilson , Nathan H. Reid , Antony J. Fairbanks
A one-step reaction for the production of unprotected glycosyl C-sulfonates directly from reducing sugars in aqueous solution has been developed, avoiding the use of any protecting groups. The reaction is equally applicable to disaccharides. The structure of the β-gluco C-sulfonate was confirmed by X-ray crystallography. Investigations showed that it did not inhibit almond β-glucosidase at a concentration of 100 μM.
{"title":"One step aqueous synthesis of unprotected glycosyl C-sulfonates","authors":"Govind P. Singh , Flinta E.D. Wilson , Nathan H. Reid , Antony J. Fairbanks","doi":"10.1016/j.carres.2025.109411","DOIUrl":"10.1016/j.carres.2025.109411","url":null,"abstract":"<div><div>A one-step reaction for the production of unprotected glycosyl C-sulfonates directly from reducing sugars in aqueous solution has been developed, avoiding the use of any protecting groups. The reaction is equally applicable to disaccharides. The structure of the β-<em>gluco</em> C-sulfonate was confirmed by X-ray crystallography. Investigations showed that it did not inhibit almond β-glucosidase at a concentration of 100 μM.</div></div>","PeriodicalId":9415,"journal":{"name":"Carbohydrate Research","volume":"551 ","pages":"Article 109411"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present study, we designed to link the coumarin molecule to chitosan via a triazole group and synthesized chitosan-coumarin derivatives, which were further quaternized in one step in order to further improve their solubility to obtain a second series of chitosan-coumarin ammonium salt derivatives. The structures of these chitosan derivatives were verified by FT-IR and 1H NMR. They were tested for their antioxidant activities. The experimental results showed that the derivatives had excellent free radical scavenging ability. The introduction of the coumarin moiety significantly improved the antioxidant activity, and the scavenging capacity was much higher than that of the chitosan feedstock in all three antioxidant tests. Overall, the scavenging capacity of chitosan-coumarin ammonium salt derivatives was slightly higher than that of chitosan-coumarin derivatives, with the highest scavenging rates in all three tests. Compound 8B scavenged 98.74 % (0.01 mg/mL) of superoxide anion radicals, compound 8D scavenged 95.5 % (0.3 mg/mL) of DPPH radicals and compound 8A scavenged 92.97 % (0.2 mg/mL) of hydroxyl radicals. Toxicity assays used L929 cells demonstrated that there was no significant toxicity of the derivatives. The results indicated that the chitosan derivatives described herein were safe and non-toxic and have good antioxidant activity.
{"title":"Synthesis and antioxidant evaluation of coumarin-functionalised chitosan: A potent, non-toxic free radical scavenging compound","authors":"Siyu Zhu , Qin Miao , Qiuhong Chen , Liguang Tian , Fang Dong , Zhanyong Guo , Qing Li","doi":"10.1016/j.carres.2024.109311","DOIUrl":"10.1016/j.carres.2024.109311","url":null,"abstract":"<div><div>In the present study, we designed to link the coumarin molecule to chitosan via a triazole group and synthesized chitosan-coumarin derivatives, which were further quaternized in one step in order to further improve their solubility to obtain a second series of chitosan-coumarin ammonium salt derivatives. The structures of these chitosan derivatives were verified by FT-IR and <sup>1</sup>H NMR. They were tested for their antioxidant activities. The experimental results showed that the derivatives had excellent free radical scavenging ability. The introduction of the coumarin moiety significantly improved the antioxidant activity, and the scavenging capacity was much higher than that of the chitosan feedstock in all three antioxidant tests. Overall, the scavenging capacity of chitosan-coumarin ammonium salt derivatives was slightly higher than that of chitosan-coumarin derivatives, with the highest scavenging rates in all three tests. Compound 8B scavenged 98.74 % (0.01 mg/mL) of superoxide anion radicals, compound 8D scavenged 95.5 % (0.3 mg/mL) of DPPH radicals and compound 8A scavenged 92.97 % (0.2 mg/mL) of hydroxyl radicals. Toxicity assays used L929 cells demonstrated that there was no significant toxicity of the derivatives. The results indicated that the chitosan derivatives described herein were safe and non-toxic and have good antioxidant activity.</div></div>","PeriodicalId":9415,"journal":{"name":"Carbohydrate Research","volume":"548 ","pages":"Article 109311"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142791033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.carres.2024.109336
Makyson R.S. Leal , Luiza R.A. Lima , Natalie E.R. Rodrigues , Paulo A.G. Soares , Maria G. Carneiro-da-Cunha , Priscilla B.S. Albuquerque
Chitooligosaccharides (CHOS) or chitosan oligosaccharides (COS) are oligomers mainly composed of d-glucosamine (GlcN) units and structured in a positively charged, basic, amino molecule obtained from the degradation of chitin/chitosan through physical, chemical, or enzymatic methods. CHOS display physicochemical properties attractive to applications from the food to the biomedical field, such as non-toxicity to humans, high water solubility, low viscosity, biocompatibility, and biodegradability. These properties also allow CHOS to exert important biological activities, for example, antioxidant, antimicrobial, anti-inflammatory, immunomodulatory, antitumor, and hypocholesterolemic ones, besides to exhibit applications in food systems, technological, and nutraceutical potential. Therefore, this study summarized the synthesis and chemical structure, biological functions, and mechanisms of action of CHOS; with this, we aimed to contribute to the knowledge about the application of CHOS from the food to the biomedical industries.
{"title":"A review on the biological activities and the nutraceutical potential of chitooligosaccharides","authors":"Makyson R.S. Leal , Luiza R.A. Lima , Natalie E.R. Rodrigues , Paulo A.G. Soares , Maria G. Carneiro-da-Cunha , Priscilla B.S. Albuquerque","doi":"10.1016/j.carres.2024.109336","DOIUrl":"10.1016/j.carres.2024.109336","url":null,"abstract":"<div><div>Chitooligosaccharides (CHOS) or chitosan oligosaccharides (COS) are oligomers mainly composed of <span>d</span>-glucosamine (GlcN) units and structured in a positively charged, basic, amino molecule obtained from the degradation of chitin/chitosan through physical, chemical, or enzymatic methods. CHOS display physicochemical properties attractive to applications from the food to the biomedical field, such as non-toxicity to humans, high water solubility, low viscosity, biocompatibility, and biodegradability. These properties also allow CHOS to exert important biological activities, for example, antioxidant, antimicrobial, anti-inflammatory, immunomodulatory, antitumor, and hypocholesterolemic ones, besides to exhibit applications in food systems, technological, and nutraceutical potential. Therefore, this study summarized the synthesis and chemical structure, biological functions, and mechanisms of action of CHOS; with this, we aimed to contribute to the knowledge about the application of CHOS from the food to the biomedical industries.</div></div>","PeriodicalId":9415,"journal":{"name":"Carbohydrate Research","volume":"548 ","pages":"Article 109336"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142784213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.carres.2024.109344
Saradhadevi Muthukrishnan , Gayathiri Gunasangkaran , Harshini Swaminathan , Peter Linus Kilambo , Anjali K. Ravi , Vijaya Anand Arumugam , Velayuthaprabhu Shanmugam , Marie Arockianathan Pushpam , Ashokkumar Kaliyaperumal , Gurusaravanan Packiaraj
Gynecological tumors are highly aggressive cancers in women, often treated with conventional treatments that can cause significant side effects. This study focuses on the preparation of chitosan nanoparticles from Nyctanthes arbor-tristis leaves, which possess anti-tumor properties, to address and overcome these issues. The successfully synthesized nanoparticles were characterized by UV-spectroscopy, DLS, TEM, and FTIR spectroscopy to analyze their physiochemical properties. In vitro studies, including cytotoxicity and scratch wound healing assays, along with staining and qRT-PCR, revealed the nanoparticles' anticancer efficacy against breast and ovarian cancer cells. The formation of Nat-CSNPs showed an absorbance peak at 221 nm, a particle size range of 41–56 nm with a spherical shape, polydispersity, and a positive surface charge. FTIR spectroscopy demonstrated the presence of functional groups associated with the synthesized Nat-CSNPs. It exhibited dose-dependent cytotoxicity, with IC50 values of 62.40 μg/ml for MDA-MB-231 and 44.7 μg/ml for SKOV3 cells. Further assays such as wound healing assay, and DAPI/AO/EtBr staining demonstrated their antiproliferative and apoptotic effects on MDA-MB-231 and SKOV3 cells. Induction of apoptosis by the chitosan-nanoparticle via upregulation of the pro-apoptotic genes (Bax, Cas3, Cas9) and downregulation of antiapoptotic genes (Bcl2) was assessed using qRT-PCR analysis. In vivo acute toxicity assessments of Nat-CSNPs on Danio rerio revealed no significant impact on glucose levels or AST, ALT, and AChE activity, indicating low toxicity. These findings underscore the potent anticancer effects of Nat-CSNPs, particularly inducing apoptosis in MDA-MB-231 and SKOV3 cell lines. While demonstrating low toxicity in Danio rerio, Nat-CSNPs are considered a promising novel anti-cancer drug for breast and ovarian cancer treatment.
{"title":"Analysing the apoptotic potential of green synthesized Nyctanthes arbor-tristis chitosan nanoparticles in MDA-MB-231 and SKOV3 cell lines","authors":"Saradhadevi Muthukrishnan , Gayathiri Gunasangkaran , Harshini Swaminathan , Peter Linus Kilambo , Anjali K. Ravi , Vijaya Anand Arumugam , Velayuthaprabhu Shanmugam , Marie Arockianathan Pushpam , Ashokkumar Kaliyaperumal , Gurusaravanan Packiaraj","doi":"10.1016/j.carres.2024.109344","DOIUrl":"10.1016/j.carres.2024.109344","url":null,"abstract":"<div><div>Gynecological tumors are highly aggressive cancers in women, often treated with conventional treatments that can cause significant side effects. This study focuses on the preparation of chitosan nanoparticles from <em>Nyctanthes arbor-tristis</em> leaves, which possess anti-tumor properties, to address and overcome these issues. The successfully synthesized nanoparticles were characterized by UV-spectroscopy, DLS, TEM, and FTIR spectroscopy to analyze their physiochemical properties. <em>In vitro</em> studies, including cytotoxicity and scratch wound healing assays, along with staining and qRT-PCR, revealed the nanoparticles' anticancer efficacy against breast and ovarian cancer cells. The formation of Nat-CSNPs showed an absorbance peak at 221 nm, a particle size range of 41–56 nm with a spherical shape, polydispersity, and a positive surface charge. FTIR spectroscopy demonstrated the presence of functional groups associated with the synthesized Nat-CSNPs. It exhibited dose-dependent cytotoxicity, with IC<sub>50</sub> values of 62.40 μg/ml for MDA-MB-231 and 44.7 μg/ml for SKOV3 cells. Further assays such as wound healing assay, and DAPI/AO/EtBr staining demonstrated their antiproliferative and apoptotic effects on MDA-MB-231 and SKOV3 cells. Induction of apoptosis by the chitosan-nanoparticle via upregulation of the pro-apoptotic genes (Bax, Cas3, Cas9) and downregulation of antiapoptotic genes (Bcl2) was assessed using qRT-PCR analysis. <em>In vivo</em> acute toxicity assessments of Nat-CSNPs on <em>Danio rerio</em> revealed no significant impact on glucose levels or AST, ALT, and AChE activity, indicating low toxicity. These findings underscore the potent anticancer effects of Nat-CSNPs, particularly inducing apoptosis in MDA-MB-231 and SKOV3 cell lines. While demonstrating low toxicity in <em>Danio rerio</em>, Nat-CSNPs are considered a promising novel anti-cancer drug for breast and ovarian cancer treatment.</div></div>","PeriodicalId":9415,"journal":{"name":"Carbohydrate Research","volume":"548 ","pages":"Article 109344"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142794397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.carres.2024.109345
Kexuan Sun , Jie Yi , Rui Dai , Hui Chen
In this study, to address the issue of solvent selection in the chemical modification of starch, a method was developed for the efficient esterification of waxy maize starch (WMS) using an acidic deep eutectic solvent composed of choline chloride and acetic acid (CCHAc-ADES). The impact of different mass fractions of CCHAc-ADES on the degree of substitution and reaction efficiency of lauric acid starch esters was explored. It was found that under the conditions of 70 wt% CCHAc-ADES, starch esters with the highest degree of substitution of 0.161 were successfully prepared, achieving an esterification efficiency of 79.63 %. 13C and 1H nuclear magnetic resonance spectroscopy, X-ray diffraction and gel permeation chromatography revealed that CCHAc-ADES acted within the surface voids of WMS particles without seriously damaging the WMS structure, making it a favorable solvent for chemical modification of WMS. By monitoring changes in the morphology, relative crystallinity, particle size, and hydrophobicity of esterified WMS in CCHAc-ADES, the formation mechanism of lauric acid starch esters was inferred, primarily related to the competitive hydrogen bonding of CCHAc-ADES with WMS. The method proposed in this study allows for the preparation of long-chain fatty acid starch esters without the use of any additional chemicals or enzymes, offering significant guidance for the application of deep eutectic solvents in green synthesis.
{"title":"Highly efficient esterification of waxy maize starch in choline chloride/acetic acid acidic deep eutectic solvent system","authors":"Kexuan Sun , Jie Yi , Rui Dai , Hui Chen","doi":"10.1016/j.carres.2024.109345","DOIUrl":"10.1016/j.carres.2024.109345","url":null,"abstract":"<div><div>In this study, to address the issue of solvent selection in the chemical modification of starch, a method was developed for the efficient esterification of waxy maize starch (WMS) using an acidic deep eutectic solvent composed of choline chloride and acetic acid (CCHAc-ADES). The impact of different mass fractions of CCHAc-ADES on the degree of substitution and reaction efficiency of lauric acid starch esters was explored. It was found that under the conditions of 70 wt% CCHAc-ADES, starch esters with the highest degree of substitution of 0.161 were successfully prepared, achieving an esterification efficiency of 79.63 %. <sup>13</sup>C and <sup>1</sup>H nuclear magnetic resonance spectroscopy, X-ray diffraction and gel permeation chromatography revealed that CCHAc-ADES acted within the surface voids of WMS particles without seriously damaging the WMS structure, making it a favorable solvent for chemical modification of WMS. By monitoring changes in the morphology, relative crystallinity, particle size, and hydrophobicity of esterified WMS in CCHAc-ADES, the formation mechanism of lauric acid starch esters was inferred, primarily related to the competitive hydrogen bonding of CCHAc-ADES with WMS. The method proposed in this study allows for the preparation of long-chain fatty acid starch esters without the use of any additional chemicals or enzymes, offering significant guidance for the application of deep eutectic solvents in green synthesis.</div></div>","PeriodicalId":9415,"journal":{"name":"Carbohydrate Research","volume":"548 ","pages":"Article 109345"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142806462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.carres.2024.109353
Anupama Das , Shay Adio , Jeremy Brincken , Alexei V. Demchenko , Cristina De Meo
With the expanding use of phosphates as leaving groups in sialylations, little remains known about the C-5 effect towards their reactivity and stereoselectivity in the presence of a range of acceptors, and in different solvents. Herein we report the comparison between sialyl phosphate donors bearing N-acetyloxazolidinone and trifluoroacetamido functionalities at C-5. Excellent results and complete stereoselectivity were observed in several sialylations, but the outcome was influenced by the nature of the solvent and/or glycosyl acceptor.
{"title":"Sialylation reactions: Expanding the C-5 effect to phosphate leaving groups","authors":"Anupama Das , Shay Adio , Jeremy Brincken , Alexei V. Demchenko , Cristina De Meo","doi":"10.1016/j.carres.2024.109353","DOIUrl":"10.1016/j.carres.2024.109353","url":null,"abstract":"<div><div>With the expanding use of phosphates as leaving groups in sialylations, little remains known about the C-5 effect towards their reactivity and stereoselectivity in the presence of a range of acceptors, and in different solvents. Herein we report the comparison between sialyl phosphate donors bearing <em>N</em>-acetyloxazolidinone and trifluoroacetamido functionalities at C-5. Excellent results and complete stereoselectivity were observed in several sialylations, but the outcome was influenced by the nature of the solvent and/or glycosyl acceptor.</div></div>","PeriodicalId":9415,"journal":{"name":"Carbohydrate Research","volume":"548 ","pages":"Article 109353"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142863407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.carres.2024.109354
Morten Lang Zimmermann, Mikael Bols
During a synthesis of the well-known and useful building block 6A−F-hexa-O-tert-butyldimethylsilyl α-cyclodextrin (2) by silylation of α-cyclodextrin (1) we isolated as a byproduct the oversilylated 2A,6A−F-hepta-O-tert-butyldimethylsilyl α-cyclodextrin (3) where one 2-OH group has also been silylated. This unsymmetrical new compound has a remarkable 1H NMR spectrum in CDCl3 where all 11 alcohol groups are visible. We have analyzed the spectrum of 3 using 1D and 2D 800 MHz NMR and are able to assign all the 11 alcohol protons. The remarkable chemical shifts of these protons are interpreted as being due to a partial disruption of an otherwise efficient hydrogen bond network.
在通过α-环糊精(1)的硅基化合成众所周知的有用的构建块6a - f -六- o -叔丁基二甲基硅基α-环糊精(2)的过程中，我们分离出过硅基化的副产物6a - f -七- o -叔丁基二甲基硅基α-环糊精(3)，其中一个2- oh基团也被硅基化了。这个不对称的新化合物在CDCl3中具有显著的1H NMR谱，其中所有11个醇基都可见。我们使用一维和二维800 MHz核磁共振分析了3的光谱，并能够分配所有11个醇质子。这些质子的显著化学位移被解释为是由于一个原本有效的氢键网络的部分破坏。
{"title":"2A,6A−F-Hepta-O-tert-butyldimethylsilyl α-cyclodextrin – A carbohydrate undecaol with all OH groups visible in NMR indicative of a partially disrupted hydrogen bond network","authors":"Morten Lang Zimmermann, Mikael Bols","doi":"10.1016/j.carres.2024.109354","DOIUrl":"10.1016/j.carres.2024.109354","url":null,"abstract":"<div><div>During a synthesis of the well-known and useful building block 6<sup>A−F</sup>-hexa-O-<em>tert</em>-butyldimethylsilyl α-cyclodextrin (<strong>2</strong>) by silylation of α-cyclodextrin (<strong>1</strong>) we isolated as a byproduct the oversilylated 2<sup>A</sup>,6<sup>A−F</sup>-hepta-O-<em>tert</em>-butyldimethylsilyl α-cyclodextrin (<strong>3</strong>) where one 2-OH group has also been silylated. This unsymmetrical new compound has a remarkable <sup>1</sup>H NMR spectrum in CDCl<sub>3</sub> where all 11 alcohol groups are visible. We have analyzed the spectrum of <strong>3</strong> using 1D and 2D 800 MHz NMR and are able to assign all the 11 alcohol protons. The remarkable chemical shifts of these protons are interpreted as being due to a partial disruption of an otherwise efficient hydrogen bond network.</div></div>","PeriodicalId":9415,"journal":{"name":"Carbohydrate Research","volume":"548 ","pages":"Article 109354"},"PeriodicalIF":2.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142833905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-31DOI: 10.1016/j.carres.2025.109412
Chang Liu , Ning Li , Li Niu , Xu Li , Jacko Feng , Zhiming Liu
Pectin and sodium alginate (SA) were mixed to form composite films using the casting method. Antibacterial packaging films (pectin/ZA) were obtained by a simple ion exchange method with a pectin/SA blend film. The effect of Zn2⁺ on the pectin/SA blend in terms of structural, morphological, thermal, physical, and mechanical properties, as well as antibacterial activity, was investigated in detail. The FT-IR, XRD, and XPS results indicated that Zn2⁺ was successfully introduced into the pectin/SA blend film. Additionally, SEM images exhibited the uniform incorporation of Zn2⁺ into the pectin/SA blend film. Moreover, the blend film of pectin and alginate improved its thermal properties, mechanical properties, and water resistance compared to the pure pectin film. Furthermore, the pectin/ZA blend film had significant antimicrobial activity against S. aureus and E. coli, revealing its potential application in food packaging.
{"title":"The preparation, physicochemical characterization and antibacterial activity of Pectin/Zinc Alginate composite film","authors":"Chang Liu , Ning Li , Li Niu , Xu Li , Jacko Feng , Zhiming Liu","doi":"10.1016/j.carres.2025.109412","DOIUrl":"10.1016/j.carres.2025.109412","url":null,"abstract":"<div><div>Pectin and sodium alginate (SA) were mixed to form composite films using the casting method. Antibacterial packaging films (pectin/ZA) were obtained by a simple ion exchange method with a pectin/SA blend film. The effect of Zn<sup>2</sup>⁺ on the pectin/SA blend in terms of structural, morphological, thermal, physical, and mechanical properties, as well as antibacterial activity, was investigated in detail. The FT-IR, XRD, and XPS results indicated that Zn<sup>2</sup>⁺ was successfully introduced into the pectin/SA blend film. Additionally, SEM images exhibited the uniform incorporation of Zn<sup>2</sup>⁺ into the pectin/SA blend film. Moreover, the blend film of pectin and alginate improved its thermal properties, mechanical properties, and water resistance compared to the pure pectin film. Furthermore, the pectin/ZA blend film had significant antimicrobial activity against <em>S. aureus</em> and <em>E. coli</em>, revealing its potential application in food packaging.</div></div>","PeriodicalId":9415,"journal":{"name":"Carbohydrate Research","volume":"550 ","pages":"Article 109412"},"PeriodicalIF":2.4,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号