TY - JOUR A1 - Tian, Guang-Zong A1 - Hu, Jing A1 - Zhang, Heng-Xi A1 - Rademacher, Christoph A1 - Zou, Xiao-Peng A1 - Zheng, Hong-Ning A1 - Xu, Fei A1 - Wang, Xiao-Li A1 - Linker, Torsten A1 - Yin, Jian T1 - Synthesis and conformational analysis of linear homo- and heterooligomers from novel 2-C-branched sugar amino acids (SAAs) JF - Scientific reports N2 - Sugar amino acids (SAAs), as biologically interesting structures bearing both amino and carboxylic acid functional groups represent an important class of multifunctional building blocks. In this study, we develop an easy access to novel SAAs in only three steps starting from nitro compounds in high yields in analytically pure form, easily available by ceric (IV) mediated radical additions. Such novel SAAs have been applied in the assembly of total nine carbopeptoids with the form of linear homo-and heterooligomers for the structural investigations employing circular dichroism (CD) spectroscopy, which suggest that the carbopeptoids emerge a well-extended, left (or right)-handed conformation similar to polyproline II (PPII) helices. NMR studies also clearly demonstrated the presence of ordered secondary structural elements. 2D-ROESY spectra were acquired to identify i+1NH <-> (C1H)-C-i, (C2H)-C-i correlations which support the conformational analysis of tetramers by CD spectroscopy. These findings provide interesting information of SAAs and their oligomers as potential scaffolds for discovering new drugs and materials. Y1 - 2018 U6 - https://doi.org/10.1038/s41598-018-24927-6 SN - 2045-2322 VL - 8 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Yang, Xiaoping A1 - Darko, Kwame Oteng A1 - Huang, Yanjun A1 - He, Caimei A1 - Yang, Huansheng A1 - He, Shanping A1 - Li, Jianzhong A1 - Li, Jian A1 - Hocher, Berthold A1 - Yin, Yulong T1 - Resistant starch regulates gut microbiota BT - structure, biochemistry and cell signalling JF - Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry and pharmacology N2 - Starch is one of the most popular nutritional sources for both human and animals. Due to the variation of its nutritional traits and biochemical specificities, starch has been classified into rapidly digestible, slowly digestible and resistant starch. Resistant starch has its own unique chemical structure, and various forms of resistant starch are commercially available. It has been found being a multiple-functional regulator for treating metabolic dysfunction. Different functions of resistant starch such as modulation of the gut microbiota, gut peptides, circulating growth factors, circulating inflammatory mediators have been characterized by animal studies and clinical trials. In this mini-review, recent remarkable progress in resistant starch on gut microbiota, particularly the effect of structure, biochemistry and cell signaling on nutrition has been summarized, with highlights on its regulatory effect on gut microbiota. KW - Resistant starch KW - Gut microbiota KW - Nutrition Y1 - 2017 U6 - https://doi.org/10.1159/000477386 SN - 1015-8987 SN - 1421-9778 VL - 42 IS - 1 SP - 306 EP - 318 PB - Karger CY - Basel ER - TY - THES A1 - Yin, Jian T1 - Syntheses and transformations of 2-C-Malonyl substituted carbohydrates Y1 - 2009 CY - Potsdam ER - TY - JOUR A1 - Yin, Jian A1 - Linker, Torsten T1 - Convenient synthesis of bicyclic carbohydrate 1,2-lactones and their stereoselective opening to 1- functionalized glucose derivatives N2 - Closed and re-opened for business: C-2 branched carbohydrates 1 cyclize under conditions of decarboxylation to the hitherto unknown carbohydrate 1,2-lactones 2 in high yields. The gluco isomer can be opened at the anomeric position with various nuceophiles in the presence of Sc(OTf)3, which allows the stereoselective synthesis of 1-functionalized glucose derivatives 3. Thus, 1,2-bis-C-branched saccharides become available in only a few steps starting from glycals. Y1 - 2009 UR - http://www3.interscience.wiley.com/cgi-bin/jhome/26293/ U6 - https://doi.org/10.1002/chem.200802178 SN - 0947-6539 ER - TY - JOUR A1 - Yin, Jian A1 - Linker, Torsten T1 - Stereodivergent syntheses at the glucose backbone N2 - Both diastereomers of 2-C-branched carbohydrates with various functional groups are selectively available from the same malonate precursor in good yields in only a few steps. Y1 - 2009 UR - http://www.rsc.org/Publishing/Journals/OB/index.asp U6 - https://doi.org/10.1039/B918893m SN - 1477-0520 ER - TY - JOUR A1 - Pimpalpalle, Tukaram M. A1 - Yin, Jian A1 - Linker, Torsten T1 - Barton radical reactions of 2-C-branched carbohydrates JF - Organic & biomolecular chemistry : an international journal of synthetic, physical and biomolecular organic chemistry N2 - Barton esters have been introduced into the side chain of carbohydrates with high yields in only a few steps from easily available glycals. Their radical reactions afford 2-C-methyl and 2-C-bromomethyl hexoses, pentoses and disaccharides in good yields in analytically pure form. Since the Barton esters have been synthesized by an oxidative radical addition and their transformations by reductive radical processes, our results demonstrate the power of such reactions in carbohydrate chemistry. Y1 - 2012 U6 - https://doi.org/10.1039/c1ob06370g SN - 1477-0520 VL - 10 IS - 1 SP - 103 EP - 109 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Yin, Jian A1 - Linker, Torsten T1 - Stereoselective diversity-oriented syntheses of functionalized saccharides from bicyclic carbohydrate 1,2-lactones JF - Tetrahedron N2 - Bicyclic carbohydrate 1,2-lactones have been synthesized in only two steps and high yields by saponification and subsequent cyclization from known malonate addition products to glycals. The gluco-configured lactone serves as an important precursor for diversity-oriented syntheses. Thus, stereoselective opening of the lactone ring was realized with various nucleophiles in the presence of Sc(OTf)(3). This enabled the introduction of different substituents at the anomeric position, to afford a broad variety of 1-functionalized carbohydrates. On the other hand, stereoselective alpha-substitution of the gluco-configured lactone with different electrophiles and subsequent ring opening gives a collection of 2-functionalized saccharides. More than 30 products have been isolated in analytically pure form, and their configurations were unequivocally established by various NMR methods. Thus, carbohydrate 1,2-lactones are attractive precursors for the stereoselective synthesis of diverse saccharides. KW - Carbohydrates KW - Lactones KW - Glycosides KW - Molecular diversity KW - Synthetic methods Y1 - 2011 U6 - https://doi.org/10.1016/j.tet.2011.01.069 SN - 0040-4020 VL - 67 IS - 13 SP - 2447 EP - 2461 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Wang, Xuebin A1 - Wang, Xiaoli A1 - Hu, Jing A1 - Wang, Zhaoya A1 - Pimpalpalle, Tukaram M. A1 - Linker, Torsten A1 - Yin, Jian T1 - Study on the Synthesis of Novel Sugar Amino Acids T1 - 新型糖氨基酸类化合物的合成研究 JF - Acta chimica Sinica = Huaxue-xuebao N2 - Sugar amino acids (SAAs) are carbohydrate derivatives bearing both amino and carboxylic acid functional groups. SAAs represent an important class of multifunctional building blocks, which are amenable to serve as glycomimetics or peptidomimetics with well-defined structures and useful properties. Because SAAs exist in nature in many forms with various biological activities, recently, many unnatural SAAs, as the demand for finding new molecules to discover new drugs and new materials, have been designed and synthesized by a number of research groups. In this paper, we have developed a convenient method for the synthesis of novel SAAs gluco-7 and galacto-7 for the first time. The structure of gluco-7 was similar to the natural SAA glucosaminuronic acid that was a component of many typical bacterial cell walls and could be used for the preparation of type D flu vaccine; while galacto-7 was similar to the natural SAA galactosaminuronic acid that was one of bacterial Vi-antigen components of Escherichia coli. Starting from unexpensive and commercially available 3,4,6-tri-O-acetyl-D-glucal and 3,4,6-tri-O-acetyl-D-galactal, two novel SAAs gluco-7 and galacto-7 were achieved in the linear 6 steps with 34% overall yield and 19% overall yield, respectively. The key reactions included radical addition, decarboxylation, iodine generation reaction, azide reaction and reductive amination reaction. The crucial step was the synthesis of the target compound gluco-7 from gluco-6. By using method A, the target compound gluco-7 was obtained in 4 steps with 63% overall yield. To optimize the transformation from gluco-6 to gluco-7, method B was developed to generate gluco-7 by using one-pot reaction successfully with 76% yield only in one step. It proved that method B was superior to method A with shorter steps and higher yields. All the new compounds were characterized by IR, H-1 NMR, C-13 NMR and HRMS data. Study on the synthesis and biological evaluation of linear and cyclic oligomers derived from gluco-7 and galacto-7 are currently in progress. KW - sugar amino acids KW - glycal KW - radical addition KW - one-pot reaction KW - synthesis Y1 - 2015 U6 - https://doi.org/10.6023/A15030205 SN - 0567-7351 VL - 73 IS - 7 SP - 699 EP - 704 PB - Science China Press CY - Beijing ER - TY - JOUR A1 - Yin, Jian A1 - Linker, Torsten T1 - Recent advances in the stereoselective synthesis of carbohydrate 2-C-analogs JF - Organic & biomolecular chemistry : an international journal of synthetic, physical and biomolecular organic chemistry N2 - C-branched carbohydrates are of current interest for glycochemistry, are widely found in nature and serve as important subunits in many antibiotics, bacterial polysaccharides and macrolides. Among C-functionalized saccharides, 2-C-branched carbohydrates represent challenging structures for synthetic chemists, since in contrast to C-glycosides they are not easily accessible from glycosyl bromides or other simple precursors. In this perspective we want to summarize recent approaches to 2-C-branched carbohydrates over the past fifteen years. The two main strategies are based on ring-opening of 1,2-cyclopropanated carbohydrates by various reagents, as well as radical additions to glycals and further transformations, developed in our group. Both methods are characterized by high stereoselectivities and good yields and give access to a broad variety of functionalized carbohydrate 2-C-analogs. Y1 - 2012 U6 - https://doi.org/10.1039/c2ob06529k SN - 1477-0520 VL - 10 IS - 12 SP - 2351 EP - 2362 PB - Royal Society of Chemistry CY - Cambridge ER -