Article
Engineering, Environmental
Evgeny E. Tereshatov, Jonathan D. Burns, Steven J. Schultz, Brooklyn D. Green, Gabriela A. Picayo, Laura A. McCann, Lauren A. McIntosh, Gabriel C. Tabacaru, Austin Abbott, Matthew Berko, Emily Engelthaler, Kris Hagel, Travis Hankins, Bryan Harvey, Lauren Hoekstra, Kylie Lofton, Sebastian Regener, Robert Rider, Maxwell Sorensen, Alexandra Tabacaru, David Thomas, Justin Tobar, Zachary Tobin, Sherry J. Yennello
Summary: A systematic study on astatine (At) sorption on extraction chromatography resins from nitric acid media has been conducted at Texas A&M University. Commercially available resins such as LN, TK400, SR, TRU, and UTEVA were included in this study. Understanding the behavior of At in nitric acid solutions is crucial for the development of a fast and reliable separation and purification system. The results showed high distribution coefficients for all the studied resins, with TRU and UTEVA resins reaching values as high as 400. The sorption uptake followed the order: TRU ≥ UTEVA > TK400 ≥ SR > LN. Thermodynamic models were developed for each resin to suggest possible mechanisms of At sorption, and sorption constants were estimated. Additionally, a mathematical model was proposed to describe bismuth (Bi) sorption by the studied resins in nitric acid media, and separation factors of At and Bi were estimated using the ratio of fit functions assigned to the same resin and acidity. Only the TRU resin was found to be unsuitable for efficient At isolation from Bi, while the other four resins showed promising results.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Jessica Jung, Lars Kaiser, Hans-Peter Deigner, Magnus S. Schmidt
Summary: In this study, bromoalkyl glycosides were successfully synthesized in microreactor scale by Fischer glycosylation, achieving yields between 24% and 40% after purification using various acidic catalysts and conditions. Some experiments demonstrated yields 180% higher than with previously known methods. Additionally, reversed-phase flash chromatography was shown to be more successful for purification, and longer bromoalcohols were found to be more compatible under these reaction conditions.
JOURNAL OF FLOW CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Xian-Yang Zhou, Ling-Xin Li, Zhen Zhang, Shi-Chao Duan, Ying-Wen Huang, Yi-Yang Luo, Xiao-Dong Mu, Zhi-Wei Chen, Yong Qin, Jing Hu, Jian Yin, Jin-Song Yang
Summary: Acinetobacter baumannii poses a serious threat to global health, and its lipopolysaccharide (LPS) has been found to have antigenic properties. Research has identified a potential antigenic epitope in one of the branches of the LPS, which is attractive for the development of carbohydrate vaccines against A. baumannii.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Lifeng Sun, Pradeep Chopra, Geert-Jan Boons
Summary: A new method for the synthesis of heparan sulfate oligosaccharides composed of unsulfonated fragments of different lengths was reported. Competition binding studies showed that the length of the unsulfonated fragment modulates the binding of chemokines.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Chun-Wei Chang, Mei-Huei Lin, Chieh-Kai Chan, Kuan-Yu Su, Chia-Hui Wu, Wei-Chih Lo, Sarah Lam, Yu-Ting Cheng, Pin-Hsuan Liao, Chi-Huey Wong, Cheng-Chung Wang
Summary: The acceptor nucleophilic constants (Aka) database quantifies the nucleophilicity of hydroxyl groups in glycosylation reactions, accurately predicting stereoselectivity and yield.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Analytical
Yusi Cui, Dylan Nicholas Tabang, Zishan Zhang, Min Ma, Andrew J. Alpert, Lingjun Li
Summary: The well-hydrated counterion selectively increases retention of charged analyte in hydrophilic interaction chromatography, especially in ERLIC. This method was successfully applied in proteomics for isolating peptides with specific PTMs, with magnesium trifluoroacetate as the best salt additive. The study showed significant improvement in selectivity and identified peptides that were previously underestimated in abundance.
ANALYTICAL CHEMISTRY
(2021)
Article
Chemistry, Physical
Yuexin Liu, Yang Jiao, Huajun Luo, Nianyu Huang, Mengnan Lai, Kun Zou, Hui Yao
Summary: An effective regiodivergent synthesis of 1- and 3-thiosugars was achieved using palladium and cobalt catalysis, respectively. The difference in the interaction of thiol moieties with Pd and Co catalysis conditions led to the selective formation of beta-1-thiosugars and (3S)-3-thiosugars. Experimental and theoretical calculations supported the proposed mechanism and provided insights into the regioselectivity based on the bond lengths of key intermediates.
Article
Chemistry, Multidisciplinary
Lea Spitzer, Sebastien Lecommandoux, Henri Cramail, Francois Jerome
Summary: An efficient method has been developed to synthesize end-functionalized oligosaccharides from unprotected monosaccharides, using a one-pot/two-step approach. The monosaccharides were first functionalized with an alkyne group at the anomeric position, then oligomerized to reach a DPn of up to 8. The obtained oligosaccharides showed complete propargylation and could be coupled to oleic acid to produce bio-based surfactants.
Article
Chemistry, Multidisciplinary
Yuanyuan Bai, Xiaohong Yang, Hai Yu, Xi Chen
Summary: Innovation in process development is crucial for the industrial and laboratory production of organic compounds, such as HMOs, through biocatalysis. A substrate and process engineering strategy called MSOPME design allows for efficient synthesis of HMOs, including long-chain oligosaccharides, without the need for isolation of intermediate products. The method can be scaled up for large-scale synthesis and automation.
Article
Chemistry, Physical
David Teze, Joan Coines, Folmer Fredslund, Kshatresh D. Dubey, Gonzalo N. Bidart, Paul D. Adams, John E. Dueber, Birte Svensson, Carme Rovira, Ditte H. Welner
Summary: The study found that UGT1 from Polygonum tinctorium can catalyze N-, O-, or S-glycosylation with similar rates, and elucidated the molecular basis of N-, O-, and S-specificities using experimental mutagenesis and simulations. It also showed that the active site can be engineered to increase or favor one of the three glycosylation activities over another, leading to the design of more active and specific enzyme variants for glycoside production.
Article
Chemistry, Multidisciplinary
Owen T. Tuck, Eric T. Sletten, Jose Danglad-Flores, Peter H. Seeberger
Summary: Research shows that glycosyl donor activation reactions at different temperatures exhibit diversity, and can avoid deleterious side reactions and reduce the amount of building blocks required by using an activation temperature. This finding contributes to optimizing the usage of glycosyl donors and improving the efficiency of oligosaccharide synthesis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Xiaona Li, Cristina Di Carluccio, He Miao, Lvfeng Zhang, Jintao Shang, Antonio Molinaro, Peng Xu, Alba Silipo, Biao Yu, You Yang
Summary: We report a promoter-controlled cycloglycosylation approach for the synthesis of cyclic α-(1→6)-linked mannosides up to a length of 32 units. The method relies on the role of a gold(I) complex in the proper preorganization of the ultra-large cyclic transition state. NMR experiments and a computational study revealed that the cyclic 2-mer, 4-mer, 8-mer, 16-mer, and 32-mer mannosides adopted different conformational states and shapes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Chaoyu Hu, Shengjie Wu, Fei He, Deqin Cai, Zhuojia Xu, Wenjing Ma, Yating Liu, Bangguo Wei, Tiehai Li, Kan Ding
Summary: Bioactive polysaccharides are potential target molecules for drug development, but the synthesis of branched complex polysaccharides with well-defined structures is challenging. In this study, a highly branched heptadecasaccharide moiety of a native bioactive polysaccharide from Carthamus tinctorius L. was efficiently synthesized, and its biological activity in targeting galectin-3 and inhibiting pancreatic cancer cell growth was demonstrated.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Peng Wen, Peijing Jia, Qiuhua Fan, Bethany J. McCarty, Weiping Tang
Summary: A streamlined iterative assembly of thio-oligosaccharides was developed by aqueous glycosylation, efficiently synthesizing 1,2-trans S-glycosides with high chemo- and stereoselectivity at room temperature. The method was successfully applied to the synthesis of a trimannoside moiety of N-linked glycans core region.
Article
Chemistry, Organic
Joshua M. Kofsky, Gour C. Daskhan, Matthew S. Macauley, Chantelle J. Capicciotti
Summary: A new method for synthesizing azido sugars using fluorosulfuryl azide (FSO2N3) and a Cu(II) catalyst as a diazotransfer reagent is reported. The method allows for the conversion of hexosamine substrates to azido sugars in less than 5 minutes with quantitative yield, without the need for harsh conditions or long reaction times. The method is also applicable to other amino sugar derivatives and is orthogonal to O-sulfation.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Kommera Rajkumar, Kurma Siva Hariprasad, Balasubramanian Sridhar, Bhimapaka China Raju
SYNTHETIC COMMUNICATIONS
(2016)
Article
Chemistry, Organic
Kasagani Veera Prasad, Gannerla Saidachary, Kurma Siva Hariprasad, Peethani Nagaraju, Vaidya Jayathirtha Rao, Bhimapaka China Raju
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2016)
Article
Chemistry, Multidisciplinary
Kurma Siva Hariprasad, Ajay Anand, Balaji Baburao Rathod, Amtul Zehra, Ashok Kumar Tiwari, Reddy Shetty Prakasham, Bhimapaka China Raju
Article
Chemistry, Organic
Shravani Madhunala, Siva Hariprasad Kurma, Varsha Reddy Etikala, China Raju Bhimapaka
SYNTHETIC COMMUNICATIONS
(2019)
Article
Chemistry, Organic
Veera Prasad Kasagani, Siva Hariprasad Kurma, China Raju Bhimapaka
JOURNAL OF ORGANIC CHEMISTRY
(2020)
Article
Chemistry, Medicinal
Siva Hariprasad Kurma, Shailaja Karri, Madhusudana Kuncha, Ramakrishna Sistla, China Raju Bhimapaka
BIOORGANIC & MEDICINAL CHEMISTRY LETTERS
(2020)
Article
Chemistry, Multidisciplinary
Lakshmireddy Vanammoole, Rajkumar Kommera, Siva Hariprasad Kurma, Jayathirtha Rao Vaidya, China Raju Bhimapaka
Article
Chemistry, Organic
Siva Hariprasad Kurma, Balasubramanian Sridhar, China Raju Bhimapaka
Summary: A highly regio- and stereoselective method was developed for the preparation of N-alkenylpyrazoles and chromenopyrazoles by reacting N-tosylhydrazones and salicyl N-tosylhydrazones with alkynes in the presence of La(OTf)(3) under neat conditions. This study proved to be efficient and convenient for direct access to N-alkenylpyrazoles and chromenopyrazoles through C-C, C-N, and C-O bond forming reactions, with the structure of compound 5c confirmed by X-ray analysis.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
K. Suchitra Rani, S. Ramya, K. S. Hariprasad, G. Praveena, A. Zehra, R. S. Prakasham, A. K. Tiwari, B. China Raju
Summary: 1,4-Dihydropyridinecarboxylates were prepared by reacting nicotinaldehydes with aminocrotonoates in the presence of p-TsOH at room temperature. The compounds showed promising anti-microbial, free-radical scavenging, and alpha-glucosidase inhibitory activities.
RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
James A. Ezugwu, Uchechukwu C. Okoro, Mercy A. Ezeokonkwo, Kurma S. Hariprasad, Mithun Rudrapal, David Ugwu, Neelutpal Gogoi, Dipak Chetia, Ismail Celik, Ogechi C. Ekoh
Summary: A new series of novel dipeptide sulfonamide analogues were designed and synthesized, and their in vitro and in vivo antimalarial activities were studied. The results showed significant antimalarial activity of these compounds. The in silico studies predicted high binding affinity of these compounds with the target proteins. The synthesized compounds exhibited drug-like properties, and their ADMET properties were within acceptable limits. Molecular dynamics simulation of the most active compound validated the stability of the protein-ligand complex and protein-ligand interactions.
Article
Chemistry, Organic
Siva Hariprasad Kurma, Sai Teja Kolla, Balasubramanian Sridhar, China Raju Bhimapaka
Summary: 3-(2,2-dichloroacetyl)-2H-chromen-2-ones were synthesized for the first time by treating salicyl N-tosylhydrazones with ethyl 4,4,4-trichloro-3-oxobutanoate in the presence of La(OTf)(3) and RuCl3 center dot 3H(2)O. The formation of chromenones involved C-C, C-O bond formations, detosylation, and dechlorination protocols, with the structure of one compound confirmed by single-crystal X-ray analysis. Additionally, treatment of salicyl N-tosylhydrazones with dimethyl (1-diazo-2-oxopropyl)-phosphonate in the presence of K2CO3 and RuCl3 center dot 3H(2)O provided (E)-N '-(2-hydroxybenzylidene)-N,4-dimethylbenzenesulfono hydrazide.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Veera Prasad Kasagani, Siva Hariprasad Kurma, China Raju Bhimapaka
ORGANIC & BIOMOLECULAR CHEMISTRY
(2019)
Article
Chemistry, Multidisciplinary
Kurma Siva Hariprasad, Kasagani Veera Prasad, Bhimapaka China Raju
