- One pot synthesis of thio -glycosides via aziridine opening reactions
-
A one-pot aziridine opening reaction by glycosyl thiols generated in situ from the corresponding anomeric thio-acetates affords thio-glycosides with a pseudo-disaccharide structure and an N-linked tether. The scope of the one-pot aziridine opening reaction was explored on a series of mono- and disaccharides, creating a class of pseudo-glycosidic compounds with potential for further functionalization. Unexpected anomerization of glycosyl thiols was observed under the reaction conditions and the influence of temperature, base and solvent on the isomerization was investigated. Single isomers were obtained in good to acceptable yields for mannose, rhamnose and sialic acid derivatives. The class of thio-glycomimetics synthesized can potentially be recognized by various lectins, while presenting hydrolytic and enzymatic stability. The nitrogen functionality incorporated in the glycomimetics can be exploited for further functionalization, including tethering to linkers, scaffolds or peptide residues.
- Hribernik, Nives,Tamburrini, Alice,Falletta, Ermelinda,Bernardi, Anna
-
supporting information
p. 233 - 247
(2021/01/14)
-
- A Sweet H2S/H2O2Dual Release System and Specific Protein S-Persulfidation Mediated by Thioglucose/Glucose Oxidase
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H2S and H2O2 are two redox regulating molecules that play important roles in many physiological and pathological processes. While each of them has distinct biosynthetic pathways and signaling mechanisms, the crosstalk between these two species is also known to cause critical biological responses such as protein S-persulfidation. So far, many chemical tools for the studies of H2S and H2O2 have been developed, such as the donors and sensors for H2S and H2O2. However, these tools are normally targeting single species (e.g., only H2S or only H2O2). As such, the crosstalk and synergetic effects between H2S and H2O2 have hardly been studied with those tools. In this work, we report a unique H2S/H2O2 dual donor system by employing 1-thio-β-d-glucose and glucose oxidase (GOx) as the substrates. This enzymatic system can simultaneously produce H2S and H2O2 in a slow and controllable fashion, without generating any bio-unfriendly byproducts. This system was demonstrated to cause efficient S-persulfidation on proteins. In addition, we expanded the system to thiolactose and thioglucose-disulfide; therefore, additional factors (β-galactosidase and cellular reductants) could be introduced to further control the release of H2S/H2O2. This dual release system should be useful for future research on H2S and H2O2.
- Li, Xiaolu,Ni, Xiang,Qian, Wei-Jun,Shen, Tun-Li,Xian, Ming
-
supporting information
p. 13325 - 13332
(2021/09/03)
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- Modular Synthesis of Aryl Thio/Selenoglycosides via the Catellani Strategy
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We described a novel palladium-catalyzed domino procedure for the preparation of (hetero)aryl thio/selenoglycosides. Readily available (hetero)aryl iodides and easily accessible 1-thiosugars/1-selenosugars are utilized as the substrates. Meanwhile, 10 types of sugars are quite compatible with this reaction with good regio- and stereoselectivity, high efficiency, and broad applicability (up to 89%, 53 examples). This method enables the straightforward formation of the C(sp2)-S/Se bond of (hetero)aryl thio/selenoglycosides.
- Ding, Ya-Nan,Huang, Yan-Chong,Shi, Wei-Yu,Zheng, Nian,Wang, Cui-Tian,Chen, Xi,An, Yang,Zhang, Zhe,Liang, Yong-Min
-
supporting information
p. 5641 - 5646
(2021/08/01)
-
- Improved Synthesis of 1-Glycosyl Thioacetates and Its Application in the Synthesis of Thioglucoside Gliflozin Analogues
-
An improved method to synthesize 1-glycosyl thioacetates was developed, where per-O-acetylated glycoses were allowed to directly react with potassium thioacetate (KSAc) in the presence of BF3 ? Et2O in ethyl acetate under mild conditions. This method not only overcomes the disadvantage of the traditional one-step method, which is that the odorous and toxic thioacetic acid has to be used, but also overcomes the disadvantage of the traditional two-step method, which is that the unstable intermediate, glycosyl halide, has to be synthesized from the per-O-acetylated glycose in advance. Based on this, the per-O-acetylated glucosyl disulfide and the per-O-acetylated glucosyl 1-thiol were efficiently synthesized in high yields (91 % and 90 % respectively) starting from per-O-acetylated glycoses in two-step without the need to isolate intermediate products. Through metal-catalyzed cross-coupling of per-O-acetylated glucosyl 1-thiol with aryl-iodide under very mild conditions, two thioglucoside gliflozin analogues were efficiently synthesized in high yields for the first time. These two thioglucoside gliflozin analogues were further confirmed to be stable to hydrolysis of β-glucosidase.
- Dong, Hai,Feng, Guang-Jing,Luo, tao,Lv, Jian,Wang, Shuang-Shuang,Wu, Yuzhou
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p. 2940 - 2949
(2021/07/26)
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- Preparation method and application of peracetyl-protected 1-thioglucose and glucose 1-mercaptan
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The invention belongs to the technical field of medicine and sugar chemical synthesis, and particularly relates to a preparation method and application of peracetyl-protected 1-thioglucose and glucose1-mercaptan. The preparation method comprises the following steps of reacting peracetyl-protected glucose and potassium thioacetate in an organic solvent at the temperature of between normal temperature and 50 DEG C under the catalysis of boron trifluoride diethyl ether for 4-8 hours to obtain peracetyl-protected 1-thioglucose; and dissolving the prepared peracetyl-protected 1-thioglucose in dimethylformamide, and removing thioacetyl by using hydrazine hydrate to obtain peracetyl-protected glucose 1-mercaptan. The peracetyl-protected glucose 1-mercaptan can be used for further preparing auronofen and gliclazide thioglycoside analogues. The method disclosed by the invention is mild in reaction condition, simple and convenient to operate, low in synthesis cost, relatively green and high inyield, the auronofen is a medicine for treating rheumatic arthritis, and the gliflozin thioglycoside analogue is a potential medicine for treating type 2 diabetes mellitus.
- -
-
Paragraph 0042-0046; 0050-0059
(2021/03/24)
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- Efficient generation of thiolate sugars from glycosyl Bunte salts and its application to S-glycoside synthesis
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A one-pot aqueous solution method for synthesis of S-glycoside derivatives has been developed. Firstly, unprotected sugars were converted into glycosyl Bunte salts from which thiolate sugars can be generated efficiently using Na2S. The subsequent addition reaction with vinyl compounds or organic halides has successfully been demonstrated, giving rise to the corresponding S-glycosides.
- Meguro, Yasuhiro,Noguchi, Masato,Li, Gefei,Shoda, Shin-ichiro
-
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- Synthesis and Structure-Activity Relationship Study of Antimicrobial Auranofin against ESKAPE Pathogens
-
Auranofin, an FDA-approved arthritis drug, has recently been repurposed as a potential antimicrobial agent; it performed well against many Gram-positive bacteria, including multidrug resistant strains. It is, however, inactive toward Gram-negative bacteria, for which we are in dire need of new therapies. In this work, 40 auranofin analogues were synthesized by varying the structures of the thiol and phosphine ligands, and their activities were tested against ESKAPE pathogens. The study identified compounds that exhibited bacterial inhibition (MIC) and killing (MBC) activities up to 65 folds higher than that of auranofin, making them effective against Gram-negative pathogens. Both thiol and the phosphine structures influence the activities of the analogues. The trimethylphosphine and triethylphosphine ligands gave the highest activities against Gram-negative and Gram-positive bacteria, respectively. Our SAR study revealed that the thiol ligand is also very important, the structure of which can modulate the activities of the AuI complexes for both Gram-negative and Gram-positive bacteria. Moreover, these analogues had mammalian cell toxicities either similar to or lower than that of auranofin.
- Wu, Bin,Yang, Xiaojian,Yan, Mingdi
-
supporting information
p. 7751 - 7768
(2019/09/10)
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- Dehydrative Thioglycosylation of 1-Hydroxyl Glycosides Catalyzed by In Situ-Generated AlI3
-
Thioglycosylation of 1-hydroxyl glycosides catalyzed by in situ-generated AlI3 from elemental aluminium and molecular iodine has been developed. This method provides an alternative route to access anomeric thioglycosides without the use of hazard Lewis acidic activators or per-modified activated thiol sources. The major advantages of this dehydrative procedure are environmental friendly, ease of operation, high anomeric diastereoselectivity, and mild reaction conditions.
- Weng, Shiue-Shien,Hsieh, Kun-Yi,Zeng, Zih-Jian
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p. 464 - 473
(2017/05/19)
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- Design, synthesis and biological evaluation of novel podophyllotoxin derivatives bearing 4β-disulfide/trisulfide bond as cytotoxic agents
-
A novel series of C-4β-disulfide/trisulfide-containing podophyllotoxin derivatives were designed, synthesized, and biologically evaluated for their cytotoxic activities against human cancer cell lines, including KB (Mouth Epidermal Carcinoma Cells) and KB/VCR (Vincristine-resistant Mouth Epidermal Carcinoma Cells). Most of these compounds exhibited promising moderate to good cytotoxic activities. In particular, some of them displayed even superior activities to that of etoposide, especially for KB/VCR cell lines, indicating that introduction of the disulfide/trisulfide moiety would be beneficial for overcoming the multi-drug resistant limitation of etoposide. Moreover, the metabolic evaluation of the most promising compound was further performed to reveal that disulfide bond can be stable in human plasma over 8 hours, indicating good potential of these compounds for in vivo anti-cancer activities.
- Zhu, Shi-Jun,Ying, Hua-Zhou,Wu, Yan,Qiu, Ni,Liu, Tao,Yang, Bo,Dong, Xiao-Wu,Hu, Yong-Zhou
-
p. 103172 - 103183
(2015/12/23)
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- Selective S-deacetylation inspired by native chemical ligation: practical syntheses of glycosyl thiols and drug mercapto-analogues
-
Glycosyl thiols are useful building blocks for the construction of compounds of biological and synthetic importance. Herein, we report a practical synthetic approach toward the efficient synthesis of glycosyl thiols via chemo- and regioselective S-deacetylation inspired by native chemical ligation. This strategy allows the large scale synthesis of glycosyl thiols by simple purification steps without column chromatography. In addition, deacetylation reagents (DTT) could also be recovered and regenerated by a simple process. Thiol containing taxol and artemisinin analogues were successfully prepared based on this methodology. Finally, auranofin, a glucose-based oral drug used to treat rheumatoid arthritis, was synthesized in concise steps and overall high yields.
- Shu, Penghua,Zeng, Jing,Tao, Jinyi,Zhao, Yueqi,Yao, Guangmin,Wan, Qian
-
supporting information
p. 2545 - 2551
(2015/04/22)
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- Free-radical hydrothiolation of glycals: A thiol-ene-based synthesis of S-disaccharides
-
A method for the synthesis of a new family of 1-deoxy S-disaccharides has been established via free-radical hydrothiolation of glycals by sugar thiols (thiol-ene coupling). The photoinduced coupling between four tri-O-acetyl-d-glycals and three different sugar thiols reveals that the reaction efficiency and stereoselectivity are highly dependent on the stereochemistry of the OAc groups at C3 and C4 of the glycal.
- Staderini, Samuele,Chambery, Angela,Marra, Alberto,Dondoni, Alessandro
-
supporting information; experimental part
p. 702 - 704
(2012/02/15)
-
- Synthesis of branched dithiotrisaccharides via ring-opening reaction of sugar thiiranes
-
Satisfactory procedures are described for the synthesis of 5,6- and 3,4-thiirane derivatives from the respective hexofuranose or hexopyranose epoxide precursors. The controlled ring-opening reaction of thiiranes by 1-thioaldoses was successfully accomplished to afford, regio- and stereoselectively, β-S-(1→4)-3,4-dithiodisaccharides. For instance, the regioselective attack of per-O-acetyl-1-thioglucose (16) to C-4 of 2-propyl 2,6-di-O-acetyl-3,4-epithio-α-d-galactopyranoside (14) gave the derivative of Glcp-β-S-(1→4)-3,4-dithioGlcp-O-iPr (17). This thiodisaccharide was accompanied by the (1→3)-disulfide 18, formed between 16 and 17, and the symmetric (3→3)-disulfide 19, which resulted from the oxidative dimerization of 17. However, the S-acetyl derivative of 17 could be obtained in good yield (62%) by LiAlH4 reduction of the crude mixture 17-19, followed by acetylation. The same sequence of reactions starting from 14 and the 1-thiolate of Galp afforded the per-O,S-acetyl derivative of Galp-β-S-(1→4)-3,4-dithio-α-d-Glcp-O-iPr (23), which was selectively S-deacetylated to give 25. The dithiosaccharides 17 and 25 are 3,4-di-S-analogues of derivatives of the natural disaccharides cellobiose and lactose, respectively. The ring-opening reaction of 5,6-epithiohexofuranoses of d-galacto (8) or l-altro (11) configuration with 1-thioaldoses was also regio- and stereoselective to give the respective β-S-(1→6)-linked 5,6-dithiodisaccharides 26 or 29 in excellent yields. Glycosylation of the free thiol group of 17, 25, or 26, using trichloroacetimidates as glycosyl donors, led to the corresponding branched dithiotrisaccharides. Some of them are sulfur analogues of derivatives of branched trisaccharides found in natural polysaccharides.
- Repetto, Evangelina,Manzano, Veronica E.,Uhrig, Maria Laura,Varela, Oscar
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experimental part
p. 253 - 265
(2012/02/14)
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- Sulfonamide linked neoglycoconjugates-A new class of inhibitors for cancer-associated carbonic anhydrases
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The contribution of membrane-bound carbonic anhydrases (CAs) to hypoxic tumor growth and progression in cancer implicates cancer-associated CAs as a promising drug target for oncology. In this paper, we present a new class of sulfonamide-linked neoglycoconjugate that was designed to selectively target and inhibit the extracellular domains of the cancer-relevant CA isozymes. We describe the application of novel, yet straightforward, chemistry toward the synthesis of inhibitors that comprise both S-glycosyl sulfenamides and S-glycosyl sulfonamides. We also present the CA inhibition profile of our new neoglycoconjugates, more specifically a library of 30 compounds (3-32) that were designed to optimize both SAR (structure-activity relationship) and SPR (structure-property relationship) characteristics. We show that our approach produces neutral, water-soluble, and potent inhibitors (Kis in the low nanomolar range) that target cancer-associated CAs.
- Lopez, Marie,Bornaghi, Laurent F.,Innocenti, Alessio,Vullo, Daniela,Charman, Susan A.,Supuran, Claudiu T.,Poulsen, Sally-Ann
-
experimental part
p. 2913 - 2926
(2010/08/06)
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- Facile preparation of α-glycosyl iodides by in situ generated aluminum iodide: Straightforward synthesis of thio-, seleno-, and o-glycosides from unprotected reducing sugars
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A facile and practical protocol was developed for the synthesis of glycosyl iodides using AlI3 generated in situ from cheap aluminum metal and molecular iodine. Furthermore, in combination with iodine-catalyzed per-O-acetylation, sequential synthesis of per-acetylated glycosyl iodides, per-acetylated thioglycosides, selenoglycoside, and O-glycosides from unprotected reducing sugars was also achieved with complete diastereocontrol in a one-pot version. Supplemental material is available for this article. Go to the publisher's online edition of Journal of Carbohydrate Chemistry to view the free supplemental file. Copyright Taylor & Francis Group, LLC.
- Weng, Shiue-Shien,Li, Chia-Ling,Liao, Chun-Sheng,Chen, Ting-An,Huang, Chao-Cheih,Hung, Kuo-Tung
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p. 429 - 440
(2012/06/01)
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- S-glycosyl primary sulfonamides - A new structural class for selective inhibition of cancer-associated carbonic anhydrases
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In this paper, we present a new class of carbonic anhydrase (CA) inhibitor that was designed to selectively target the extracellular domains of the cancer-relevant CA isozymes. The aromatic moiety of the classical zinc binding sulfonamide CA inhibitors is
- Lopez, Marie,Paul, Blessy,Hofmann, Andreas,Morizzi, Julia,Wu, Quoc K.,Charman, Susan A.,Innocenti, Alessio,Vullo, Daniela,Supuran, Claudiu T.,Poulsen, Sally-Ann
-
scheme or table
p. 6421 - 6432
(2010/03/31)
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- Synthesis of anomeric sulfonamides and their behaviour under radical-mediated bromination conditions
-
O-Peracetylated methyl 3-(d-glycopyranosylthio)propanoates of β-d-gluco, and α- and β-d-galacto configurations were oxidized to the corresponding S,S-dioxides (sulfones) by Oxone or MCPBA. Oxidation of the β-d-gluco derivative with H2O2/Na2WO4 gave the corresponding S-oxide (sulfoxide). DBU-induced elimination of methyl acrylate from the β-d-gluco and β-d-galacto configured S,S-dioxides (sulfones) gave O-peracetylated β-d-glycopyranosyl-1-C-sulfinates which, on treatment with H2NOSO3H, furnished the corresponding β-d-glycopyranosyl-1-C-sulfonamides. Radical-mediated bromination of the protected methyl 3-(β-d-glycopyranosylthio)propanoate S,S-dioxides gave mixtures of 1-C- and 5-C-bromoglycosyl compounds. Similar brominations of the O-peracetylated β-d-glycopyranosyl-1-C-sulfonamides resulted in the formation of α-d-glycopyranosyl bromides and 1-C- and 5-C-bromoglycosyl sulfonamides. A rationale for these observations was proposed. Methyl 3-(β-d-glucopyranosylthio)propanoate, its S,S-dioxide, and β-d-glucopyranosyl-1-C-sulfonamide proved inefficient when tested as inhibitors of rabbit muscle glycogen phosphorylase b.
- Czifrak, Katalin,Somsak, Laszlo
-
experimental part
p. 269 - 277
(2009/06/21)
-
- Solvent-free synthesis of thioglycosides by ball milling
-
Thioglycosides have been prepared in excellent yields by three different routes from a range of readily available glycosyl halides under solvent-free conditions employing a planetary ball mill.
- Ramrao Patil, Premanand,Ravindranathan Kartha
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experimental part
p. 953 - 956
(2010/04/23)
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- Synthesis of S-glycosyl primary sulfonamides
-
The synthesis of S-glycosyl sulfonamides wherein the primary sulfonamide functional group (-SO2NH2) is directly attached to the anomeric position of a carbohydrate moiety is reported. Our general approach consists of first introducing a thioacetate group at the anomeric center of a per-O-acetylated sugar derivative From this follows formation of a glycosyl sulfenamide (sugar-SNR2), oxidation of the sulfenamide to give a glycosyl N-protected sulfonamide (sugar-SO2NR2), and removal of the sulfonamide protecting (R) group to yield a primary sulfonamide at the anomeric center (sugar-SO2NH2). A variety of monoand disaccharide derivatives were synthesized using this new methodology
- Lopez, Marie,Drillaud, Nicolas,Bornaghi, Laurent F.,Poulsen, Sally-Ann
-
supporting information; experimental part
p. 2811 - 2816
(2009/09/08)
-
- α-S-GalCer: Synthesis and evaluation for iNKT cell stimulation
-
The synthesis and evaluation for iNKT stimulation of α-S-galactosylceramide is reported. Prepared by alkylation of a galactosylthiol, this analog of the potent immunostimulatory agent, KRN7000, did not stimulate iNKT cells either in vitro or in vivo.
- Blauvelt, Marisa L.,Khalili, Maryam,Jaung, Weonjoo,Paulsen, Janet,Anderson, Amy C.,Brian Wilson,Howell, Amy R.
-
supporting information; experimental part
p. 6374 - 6376
(2009/09/30)
-
- A novel method for the synthesis of thioacetates using benzyltriethyl- ammonium tetrathiomolybdate and acetic anhydride
-
Herein we report a simple and efficient methodology for the synthesis of thioacetates using benzyltriethylammonium tetrathiomolybdate and acetic anhydride as the key reagents, starting from alkyl halides in a multistep, tandem reaction process. Its application in the synthesis of orthogonally protected cysteine and anomeric β-thioglycosides has also been demonstrated.
- Nasir, Baig R. B.,Sai, Sudhir V.,Srinivasan, Chandrasekaran
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scheme or table
p. 2684 - 2688
(2009/04/16)
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- From disulfide- to thioether-linked glycoproteins
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(Chemical Presented) Strengthening the bond: The introduction of a thiol tag in combination with chemoselective ligation to form a disulfide-linked bioconjugate is a selective and useful method for site-selective protein glycosylation. The phosphine-mediated desulfurization of such glycoconjugates to their reductant-resistant thioether-linked counterparts completes a convergent, site-selective synthesis of thioether-linked glycoproteins (see scheme).
- Bernardes, Goncalo J. L.,Grayson, Elizabeth J.,Thompson, Sam,Chalker, Justin M.,Errey, James C.,El Oualid, Farid,Claridge, Timothy D. W.,Davis, Benjamin G.
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supporting information; experimental part
p. 2244 - 2247
(2009/02/07)
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- Involvement of the S-aglycon in the conformational preferences of thioglucosides
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The conformational preferences of two series of alkyl β-d-thioglucopyranosides in solution were investigated by NMR and CD. The rotamer populations of the hydroxymethyl group were found to depend on the structural nature of the S-aglycon. The population of the gt rotamer increased and that of the gg rotamer decreased as the alkyl group attached to the S atom increased in size. These rotamer populations have a linear correlation with the Taft' steric parameters, the nS s(-) σC s(-) O* exo-anomeric interaction may express these rotational preferences. Comparative analysis of the hydroxymethyl populations between alkyl O- and S-glucosides revealed identical or slightly higher gt and smaller gg populations for the latter compounds.
- Sanhueza, Carlos A.,Dorta, Rosa L.,Vazquez, Jesus T.
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p. 258 - 264
(2008/09/19)
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- The direct formation of glycosyl thiols from reducing sugars allows one-pot protein glycoconjugation
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(Figure Presented) Sweet and easy: A one-pot method consisting of direct thionation (1) followed by thiol-mediated chemoselective ligation (2) can be used for site-selective protein glycosylation. This procedure, which uses the Lawesson reagent, has been shown to be fully compatible with unprotected sugars, the products of which can be directly used in a selenenylsulfide protein glycosylation strategy.
- Bernardes, Goncalo J. L.,Gamblin, David P.,Davis, Benjamin G.
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p. 4007 - 4011
(2007/10/03)
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- Modified one-pot protocol for the preparation of thioglycosides from unprotected aldoses via S-glycosyl isothiouronium salts
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An efficient one-pot protocol for the direct preparation of thioglycosides starting from unprotected reducing sugars via S-glycosyl isothiouronium salts is reported. In this one-pot methodology, BF3·OEt2 has been used as a general catalyst for both per-O-acetylation of sugars and conversion of sugar per-O-acetates into S-glycosyl isothiouronium salts, which was allowed to react with alkylating agents in the presence of a base to furnish thioglycosides in excellent yield. Copyright Taylor & Francis, Inc.
- Tiwari, Pallavi,Agnihotri, Geetanjali,Misra, Anup Kumar
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p. 723 - 732
(2007/10/03)
-
- Design, chemical synthesis, and biological evaluation of thiosaccharide analogues of morphine- and codeine-6-glucuronide
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A series of 6-β-thiosaccharide analogues of morphine-6-glucuronide (M6G) and codeine-6-glucuronide (C6G) were synthesized and evaluated with the objective of preparing an analogue of M6G with improved biological activity. The affinity of the thiosaccharide analogues of M6G and C6G was examined by competitive binding assays at μ, δ, and κ opioid receptors. The thiosaccharide compounds in the morphine series 5b, 5e, 6a, and 6c showed 1.5-2.4-fold higher affinity for the μ receptor than M6G, but were generally less selective than M6G. The functional activity of the M6G and C6G analogues was examined with the [35S]GTP-γ-S assay. Compounds 5b and 5e were determined to be full μ agonists, whereas compounds 6a and 6c were partial μ agonists. The in vivo antinociceptive activity of compound 5b was evaluated by the tail flick latency test, giving an ED50 of 2.5 mg/kg.
- MacDougall, James M.,Zhang, Xiao-Dong,Polgar, Willma E.,Khroyan, Taline V.,Toll, Lawrence,Cashman, John R.
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p. 5809 - 5815
(2007/10/03)
-
- Reaction of 1,2-trans-glycosyl acetates with thiourea: A new entry to 1-thiosugars
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The reaction of 1,2-trans-glycosyl acetates with thiourea under boron trifluoride etherate catalysis affording acetylated S-glycosyl isothiourea derivatives is described. The isothiourea derivatives obtained can be readily transformed into the desired 1-thiosugar derivative by reaction with triethylamine and subsequent alkylation or acylation of the in situ formed 1-thioaldose.
- Ibatullin, Farid M.,Shabalin, Konstantin A.,J?nis, Janne V.,Shavva, Alexander G.
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p. 7961 - 7964
(2007/10/03)
-
- A general procedure for conversion of S-glycosyl isothiourea derivatives into thioglycosides, thiooligosaccharides and glycosyl thioesters
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A simple procedure for conversion of S-glycosyl isothiourea derivatives into thioglycosides by promotion with triethylamine is described. The reaction conditions allow the synthesis of glycosyl thioesters and some thioglycosides, which cannot be prepared using the traditional approach. The procedure has been successfully applied for preparation of thiooligosaccharides, shown by syntheses of methyl 4-thio-α-cellobioside and methyl 4-thio-α-lactoside derivatives.
- Ibatullin,Selivanov,Shavva
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p. 419 - 422
(2007/10/03)
-
- Conversion of 2-(trimethylsilyl)ethyl sulfides into thioesters
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Treatment of 2-(trimethylsilyl)ethyl sulfides with a carboxylic acid chloride and AgBF4 in CH2Cl2 furnishes the corresponding thioesters in high yields and purities. The conversion of 2-(trimethylsilyl)ethyl sulfides into synthetically versatile thioesters allows such sulfides to be used as sulfhydryl protective groups, since such sulfides are easily prepared and are stable towards many reaction conditions encountered in organic syntheses.
- Grundberg, Hans,Andergran, Magnus,Nilsson, Ulf J.
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p. 1811 - 1814
(2007/10/03)
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- STEREOSELECTIVE SYNTHESIS OF 1,2-TRANS-1-THIOGLYCOSES USING ALUMINIUM CHLORIDE: EVIDENCE FOR 1,2-CIS-1-CHLOROGLYCOPYRANOSYLPERACETATES AS THE ACTUAL REACTION INTERMEDIATES
-
Synthesis of 1,2-trans-1-thioglycosylacetates has been achieved in excellent yields from corresponding 1,2-trans-glycosylacetates using aluminium chloride via 1,2-cis-1-chloroglycopyranosylacetates with retention of configuration.
- Rajanikanth, B.,Seshadri, R.
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p. 2295 - 2296
(2007/10/02)
-