Review
Biochemistry & Molecular Biology
Akihiro Ishiwata, Katsunori Tanaka, Yukishige Ito, Hui Cai, Feiqing Ding
Summary: Controlling the stereoselectivity of 1,2-cis glycosylation is a challenging task in glycans synthesis. Various regioisomeric linkages have been identified, and strategies using inter- and intra-molecular methodologies have been explored. Recent advances in Zn salt-mediated cis glycosylation and its applications in alpha-glucans construction are summarized in this review.
Article
Chemistry, Applied
Ashwani Tiwari, Ariza Khanam, Ashwani Kumar, Mohan Lal, Pintu Kumar Mandal
Summary: L-Prolinethioamide catalyzes the stereoselective glycosylation of glycal donors to access 2-deoxyglycosides under mild reaction conditions. This method provides good yields (up to 88%) and exhibits excellent tolerance towards glycosyl acceptors and a broad substrate scope with improved stereoselectivity. It can also be applied to less nucleophilic acceptors such as phenols. Moreover, 1,1'-linked trehalose-type analogues can be synthesized using this methodology. Mechanistic studies suggest that L-prolinethioamide operates via Bronsted acid/base catalysis in this glycosylation reaction.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Koji Morimoto, Kana Yanase, Tetsuya Kajimoto, Yasuyuki Kita
Summary: A method using hypervalent iodine reagents for oxidative glycosylation was discovered, resulting in the synthesis of sugars of different sizes, providing new possibilities for further research.
Article
Chemistry, Multidisciplinary
Jicheng Wu, Peijing Jia, Rositha Kuniyil, Peng Liu, Weiping Tang
Summary: In this study, we report an efficient method for the stereoselective synthesis of challenging α-linked glycoconjugates using a Rh-II/chiral phosphoric acid (CPA)-cocatalyzed dynamic kinetic anomeric O-alkylation. By exploring various parameters of the cocatalytic system, we achieved excellent anomeric selectivity, excellent diastereoselectivity, broad substrate scope, and high efficiency for this glycosylation reaction. DFT calculations suggested that the anomeric selectivity was determined by steric interactions between the C2-carbon of the carbohydrate and the phenyl group of the metal carbenoid, while diastereoselectivity at the newly generated stereogenic center was influenced by π-π interactions with the C2-OBn substituent on the carbohydrate substrate.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Yoshiyuki Manabe, Takuya Matsumoto, Yuka Ikinaga, Yuya Tsutsui, Shota Sasaya, Yuichiro Kadonaga, Akihito Konishi, Makoto Yasuda, Tomoya Uto, Changhao Dai, Kumpei Yano, Atsushi Shimoyama, Ayana Matsuda, Koichi Fukase
Summary: The study found that catalytic glycosylations using BF3·Et2O could efficiently proceed without the use of dehydrating agents, in contrast to traditional reactions requiring excess Lewis acid and additives. Mechanistic studies showed that chemical species formed by the reaction of in situ generated HF and glass vessels are involved in the catalytic cycle.
Review
Biochemistry & Molecular Biology
Magdalena Wilczak, Magdalena Surman, Malgorzata Przybylo
Summary: Bladder cancer is the 10th most common malignancy worldwide, with a high mortality rate. Altered glycosylation of bladder cancer cells plays a crucial role in disease progression and could be used for diagnostic and therapeutic purposes.
Article
Chemistry, Organic
Siai Zhou, Xuemei Zhong, Aoxin Guo, Qian Xiao, Jiaming Ao, Wanmeng Zhu, Hui Cai, Akihiro Ishiwata, Yukishige Ito, Xue-Wei Liu, Feiqing Ding
Summary: This study presents a glucosylation strategy using ZnI2 for stereoselective construction of 1,2-cis-O-glycosidic linkages. The versatility of this approach was demonstrated with various acceptors, including complex alcohols, indicating the potential for modular synthesis of various alpha-glucans.
Article
Chemistry, Organic
Intzar Ali, M. V. Kamala Lakshmi, Ramu Sridhar Perali
Summary: The Mislow-Evans rearrangement was utilized to construct digitoxose-derived glycals used in the synthesis of cardenolides digitoxin, digoxin, and gitoxin. The scalability of the trisaccharide synthesis was demonstrated by performing reactions on a multigram scale. Glycosylation reactions between the synthesized digoxin glycal donor and aglycons digoxigenin and gitoxigenin yielded novel cardenolide derivatives.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Xu Ma, Yongliang Zhang, Xijun Zhu, Yongliang Wei, Liming Zhang
Summary: This work introduces a novel catalytic S(N)2 glycosylation method using an amide-functionalized 1-naphthoate platform as a latent glycosyl leaving group. The amide group facilitates the S(N)2 process by directing the attack of the glycosyl acceptor via H-bonding interaction, resulting in stereoinversion at the anomeric center. Additionally, the amide group enables a safeguarding mechanism by trapping oxocarbenium intermediates, minimizing stereorandom S(N)1 processes. This strategy allows for high-yielding synthesis of a wide range of glycosides with stereoinversion, including challenging 1,2-cis-linkage-rich oligosaccharides.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Dancan K. Njeri, Erik Alvarez Valenzuela, Justin R. Ragains
Summary: By substituting the benzyl groups of glucosyl imidate donors with trifluoromethyl, a substantial increase in 1,2-cis-selectivity can be achieved when activated with TMS-I in the presence of triphenylphosphine oxide. The stereoselectivity depends on the number of trifluoromethyl groups, leading to high 1,2-cis-selectivity with reactive alcohol acceptors.
Review
Chemistry, Medicinal
Elena Mendoza-Barbera, Susana Merino, Juan Tomas
Summary: Aeromonas spp. are commonly found in aquatic environments and can also be isolated from fresh and processed food. They mainly infect poikilothermic animals, but are also considered opportunistic pathogens of aquatic and terrestrial homeotherms, with some species associated with gastrointestinal and extraintestinal septicemic infections in humans.
Review
Chemistry, Multidisciplinary
Catherine Alex, Alexei V. Demchenko
Summary: This review focuses on the accomplishments in the stereoselective synthesis of beta-linked mannosides functionalized with carboxyls or amines/amides. These residues have consistently interested the glycoscience community due to both synthetic challenges and therapeutic potential, and are found in various glycoconjugates, bacterial polysaccharides, and alginates.
Article
Biochemistry & Molecular Biology
Anirban Adak, Sakshi Balasaria, Balaram Mukhopadhyay
Summary: The synthesis of the tetrasaccharide repeating unit of E. coli O131 O-antigen was achieved using a linear strategy involving rationally protected monosaccharide units derived from commercially available sugars. The challenging alpha-glycosylation of N-acetyl neuraminic acid was successfully accomplished through the activation of thioglycoside using NIS-mediated glycosylation strategy. The resulting tetrasaccharide in 3-aminopropyl glycoside form can be utilized for further glycoconjugate formation without affecting the anomeric stereochemistry.
CARBOHYDRATE RESEARCH
(2022)
Article
Biochemistry & Molecular Biology
Ekaterina D. Kazakova, Dmitry V. Yashunsky, Nikolay E. Nifantiev
Summary: The synthesis of the spacered A trisaccharide was achieved by employing a glycosyl donor with stereocontrolling groups, resulting in efficient and stereoselective formation of the required alpha-glycosylation product. The final products were deprotected and subjected to spacer biotinylation for use in biochemical studies.
Article
Biochemistry & Molecular Biology
Sachiko Hirobe, Keisuke Imaeda, Masashi Tachibana, Naoki Okada
Summary: In this study, we investigated the effects of disulphide bonding and glycosylation on the function of CAR-expressing T cells. We found that disulphide bonds and N-linked glycosylation influenced CAR expression and CAR-T cell activity, providing insights for future CAR design.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
