Article
Biochemistry & Molecular Biology
Tapasi Manna, Anup Kumar Misra
Summary: In this study, a concise synthetic strategy was developed for the synthesis of the sialic acid-containing tetrasaccharide repeating unit of Escherichia coli O131 strain's cell wall O-antigen using regio- and stereoselective glycosylation of judiciously protected sialic acid thioglycoside derivatives.
CARBOHYDRATE RESEARCH
(2022)
Article
Chemistry, Organic
Swapan Kumar Jana, Samim Sahaji, Pradip Shit, Anup Kumar Misra
Summary: A synthetic strategy involving challenging stereoselective glycosylation steps was used to successfully synthesize the hexasaccharide repeating unit corresponding to the capsular polysaccharide of Streptococcus pneumoniae type 7A.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Organic
Samim Sahaji, Pradip Shit, Anup Kumar Misra
Summary: A convergent [4+2] stereoselective block glycosylation strategy was developed for the synthesis of the hexasaccharide repeating unit of Klebsiella K19 strain's capsular polysaccharide with high yield. Temporary alkyl protecting group p-methoxybenzyl (PMB) was used and removed through glycosylation conditions. Thioglycoside served as a glycosyl acceptor in an orthogonal glycosylation reaction. TEMPO-mediated selective oxidation and thiophilic promoter N-iodosuccinimide (NIS) in combination with perchloric acid supported over silica (HClO4-SiO2) were used.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Organic
Pradip Shit, Samim Sahaji, Anup Kumar Misra
Summary: A novel synthetic strategy was developed for the synthesis of the hexasaccharide repeating unit of the capsular polysaccharide of Klebsiella serotype K-34 in very good yield. All reactions exhibited excellent yield and stereoselectivity.
Article
Chemistry, Organic
Arin Gucchait, Monalisa Kundu, Anup Kumar Misra
Summary: A pentasaccharide repeating unit corresponding to the cell wall O-antigen of Salmonella enterica O55, containing a rare sugar, has been successfully synthesized using a sequential stereoselective glycosylation strategy.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Multidisciplinary
Zijiao Hou, Jianjun Wang, Xinxin Zhang, Peng Wang, Ni Song, Ming Li
Summary: The first assembly of a conjugation-ready hexasaccharide from the capsular glycan of C. jejuni. strain BH0142 has been accomplished, which sets a solid foundation for making structurally-defined multivalent glycoconjugate vaccine candidates against C. jejuni. infections. The synthesis features efficient preparation of 6-deoxy-D -ido- heptopyranosyl fluoride donors and stereocontrolled construction of specific glycosidic linkages.
CHINESE CHEMICAL LETTERS
(2023)
Article
Biochemistry & Molecular Biology
Abhijit Rana, Pradip Shit, Anup Kumar Misra
Summary: A hexasaccharide repeating unit of Salmonella arizonae O62 was synthesized with high yield using a sequential glycosylation strategy. The desired compound was obtained with a minimum number of synthetic steps through successful regioselective glycosylation of the di-hydroxylated L-rhamnose moiety. Late stage regioselective oxidation of a primary hydroxyl group into carboxylic acid was achieved in the hexasaccharide derivative using TEMPO catalysis and [bis(acetoxy)iodo]benzene (BAIB) mediation. The glycosylation steps had high yields and stereochemical outcomes. The desired hexasaccharide was obtained in 7% overall yield in fourteen steps starting from suitably functionalized monosaccharide intermediates.
GLYCOCONJUGATE JOURNAL
(2023)
Article
Chemistry, Organic
Antara Ghosh, Suvarn S. Kulkarni
Summary: The total synthesis of the trisaccharide repeating unit of Streptococcus pneumoniae zwitter-ionic polysaccharide Sp1, containing a rare sugar, was achieved via highly stereoselective glycosylations and late-stage oxidation in 21 steps with an overall yield of 4.4%.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Ennus K. Pathan, Bhaswati Ghosh, Ananda Rao Podilapu, Suvarn S. Kulkarni
Summary: The total synthesis of the repeating unit of Bacteroides fragilis zwitterionic polysaccharide A1 (PS A1) was achieved through efficient synthesis of D-galactosamine and AAT building blocks from cheap and abundant n-mannose, followed by highly stereoselective installation of all glycosidic bonds. This involved a 17-step longest linear sequence with an overall yield of 3.47%.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Pradip Shit, Anup Kumar Misra
Summary: A concise synthetic strategy has been developed for the synthesis of the pentasaccharide repeating unit of the capsular polysaccharide of Escherichia coli (E. coli) strain using block [2+3] stereoselective glycosylation. The target pentasaccharide derivative was obtained in good yield, demonstrating the effectiveness of this method.
Article
Multidisciplinary Sciences
Hongcheng Zhao, Nan Sun, Lin Huang, Ruyi Qian, Xianyong Lin, Chengliang Sun, Yongguan Zhu
Summary: The molecular mechanism of root development mediated by the beneficial bacterium Azospirillum brasilense is not fully understood. A. brasilense induces extensive transcriptional changes but inhibits primary root elongation in Arabidopsis. Through analysis of root cell type-specific markers, it was found that A. brasilense does not alter the overall organization or cell division of the primary root meristem. The inhibition of root elongation is primarily due to the reduction of cell elongation, which is caused by bacterially activated peroxidase leading to cell wall cross-linking. The activation of peroxidase, in combination with the downregulation of cell wall loosening enzymes, results in an increase in cell wall thickness.
Article
Chemistry, Organic
Abhijit Rana, Anup Kumar Misra
Summary: An acidic pentasaccharide repeating unit of Providencia alcalifaciens O45:H25 strain has been synthesized using multi-step stereoselective glycosylation. The p-methoxybenzyl (PMB) group was used as an in situ removable protecting group, and the D-glucuronic acid moiety was installed by selective oxidation. Thioglycoside donors were used for glycosylation with good stereochemistry and yields.
Article
Chemistry, Organic
Archana A. Shirsat, Diksha Rai, Balasaheb K. Ghotekar, Suvarn S. Kulkarni
Summary: An efficient total synthesis of the conjugation-ready trisaccharide repeating unit of Staphylococcus aureus strain M is reported. The main challenges include acquiring rare sugars (D-FucNAc and D-GalNAcA) and establishing consecutive 1,2-cis-glycosidic linkages between them. Stereoselective 1,2-cis glycosylation was achieved with benzylidene protected D-galactosamine thioglycoside using a DMF modulated preactivation glycosylation method, while consecutive 1,2-cis linkages were installed with solvent participation. The total synthesis of the trisaccharide repeating unit was accomplished in 24 steps with an overall yield of 4.5%.
Article
Chemistry, Organic
Johny M. Nguyen, Steven D. Townsend
Summary: Zwitterionic carbohydrate modifications like phosphoethanol-amine (PEtN) play a crucial role in host-pathogen interactions, but the exact purpose of PEtN modification remains unclear. Researchers have synthesized the P. temperata zwitterionic trisaccharide repeating unit in 32 steps, using H-phosphonate chemistry to install the PEtN arm, to study the potential mechanisms of PEtN modification.
Article
Chemistry, Organic
Krishna Puri, Suvarn S. Kulkarni
Summary: Here, we report the total synthesis of the phosphorylated zwitterionic trisaccharide repeating unit of Photo-rhabdus temperata subsp. cinerea 3240. The efficient route involves regio- and stereoselective assembly of trisaccharide with rare deoxyamino sugar AAT at the nonreducing end, late stage oxidation, and installation of a phosphate linker on the trisaccharide. The total synthesis was completed via a longest linear sequence of 24 steps in 6.5% overall yield.
Article
Chemistry, Organic
Samir Ghosh, Sharmeen Nishat, Peter R. Andreana
JOURNAL OF ORGANIC CHEMISTRY
(2016)
Article
Chemistry, Organic
Pradheep Eradi, Samir Ghosh, Peter R. Andreana
Article
Chemistry, Medicinal
Samir Ghosh, Pallavi Tiwari, Shashi Pandey, Anup Kumar Misra, Vinita Chaturvedi, Anil Gaikwad, Shalini Bhatnagar, Sudhir Sinha
BIOORGANIC & MEDICINAL CHEMISTRY LETTERS
(2008)
Article
Chemistry, Medicinal
Samir Ghosh, Anup Kumar Misra, Gitika Bhatia, M. M. Khan, A. K. Khanna
BIOORGANIC & MEDICINAL CHEMISTRY LETTERS
(2009)
Article
Biochemistry & Molecular Biology
Samir Ghosh, Anup Kumar Misra
JOURNAL OF CARBOHYDRATE CHEMISTRY
(2009)
Article
Biochemistry & Molecular Biology
Samir Ghosh, Peter R. Andreana
JOURNAL OF CARBOHYDRATE CHEMISTRY
(2014)
Article
Chemistry, Organic
Shashi Pandey, Samir Ghosh, Anup Kumar Misra
SYNTHESIS-STUTTGART
(2009)
Article
Chemistry, Inorganic & Nuclear
Samir Ghosh, Anup Kumar Misra
TETRAHEDRON-ASYMMETRY
(2009)
Article
Chemistry, Inorganic & Nuclear
Samir Ghosh, Anup Kumar Misra
TETRAHEDRON-ASYMMETRY
(2010)
Article
Biochemistry & Molecular Biology
F. Hossain, S. Nishat, S. Ghosh, S. Boga, G. T. Hymel, P. R. Andreana
JOURNAL OF CARBOHYDRATE CHEMISTRY
(2020)
Article
Chemistry, Medicinal
Brendan T. Freitas, Daniil A. Ahiadorme, Rahul S. Bagul, Ian A. Durie, Samir Ghosh, Jarvis Hill, Naomi E. Kramer, Jackelyn Murray, Brady M. O'Boyle, Emmanuel Onobun, Michael G. Pirrone, Justin D. Shepard, Suzanne Enos, Yagya P. Subedi, Kapil Upadhyaya, Ralph A. Tripp, Brian S. Cummings, David Crich, Scott D. Pegan
Summary: In the past 20 years, both severe acute respiratory syndrome coronavirus-1 and severe acute respiratory syndrome coronavirus-2 have caused zoonotic outbreaks in humans. The PLpro enzyme from a subgroup 2b bat coronavirus has been studied to identify structural features and substrate specificity. Based on this, 30 novel noncovalent inhibitors for subgroup 2b PLpro enzymes were designed, providing new directions for antiviral development against this group of coronaviruses.
ACS INFECTIOUS DISEASES
(2022)
Article
Chemistry, Multidisciplinary
Samir Ghosh, Kevin R. Trabbic, Mengchao Shi, Sharmeen Nishat, Pradheep Eradi, Kristopher A. Kleski, Peter R. Andreana