Browsing by Author "Ingle, Arun B."

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C6 picoloyl protection: a remote stereodirecting group for 2-deoxy-beta-glycoside formation
(2015-01-01)
Ruei, Jyh-Herng
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Venukumar, Patteti
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Ingle, Arun B.
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Mong, Kwok-Kong Tony
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應用化學系
We reported a remote control glycosylation method using the picoloyl protecting group for 2-deoxy-beta-glycosidic bond formation. The method is applicable to various 2-deoxythioglycosyl donors and the utility is illustrated by the synthesis of a deoxytrisaccharide component of landomycins.
Chemical Synthesis of the O-Antigen Repeating Unit of Escherichia coli O86 by an N-Formylmorpholine-Modulated One-Pot Glycosylation Strategy
(2014-08-01)
Ingle, Arun B.
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Chao, Chin-Sheng
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Hung, Wei-Cheng
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Mong, Kwok-Kong Tony
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應用化學系
The synthesis of the O-antigen pentasaccharide repeating unit of the cell wall of Gram-negative bacteria Escherichia coli O86 is reported. The synthesis features the use of an N-formylmorpholine (NFM)-modulated glycosylation method for the construction of 1,2-cis alpha-glycosidic linkages and an [1+1+2] iterative one-pot alpha-glycosylation strategy to accelerate the assembly of the tetrasaccharide backbone.
Metabolic labelling of cholesteryl glucosides in Helicobacter pylori reveals how the uptake of human lipids enhances bacterial virulence
(2016-01-01)
Jan, Hau-Ming
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Chen, Yi-Chi
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Shih, Yu-Yin
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Huang, Yu-Chen
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Tu, Zhijay
Helicobacter pylori infects approximately half of the human population and is the main cause of various gastric diseases. This pathogen is auxotrophic for cholesterol, which it converts upon uptake to various cholesteryl alpha-glucoside derivatives, including cholesteryl 6'-acyl and 6'-phosphatidyl alpha-glucosides (CAGs and CPGs). Owing to a lack of sensitive analytical methods, it is not known if CAGs and CPGs play distinct physiological roles or how the acyl chain component affects function. Herein we established a metabolite-labelling method for characterising these derivatives qualitatively and quantitatively with a femtomolar detection limit. The development generated an MS/MS database of CGds, allowing for profiling of all the cholesterol-derived metabolites. The subsequent analysis led to the unprecedented information that these bacteria acquire phospholipids from the membrane of epithelial cells for CAG biosynthesis. The resulting increase in longer or/and unsaturated CAG acyl chains helps to promote lipid raft formation and thus delivery of the virulence factor CagA into the host cell, supporting the idea that the host/pathogen interplay enhances bacterial virulence. These findings demonstrate an important connection between the chain length of CAGs and the bacterial pathogenicity.
Modulating glycosylation with exogenous nucleophiles: an overview
(2014)
Mulani, Shaheen K.
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Hung, Wei-Cheng
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Ingle, Arun B.
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Shiau, Kai-Sheng
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Mong, Kwok-Kong Tony
The major challenge in carbohydrate synthesis is stereochemical control of glycosidic bond formation. Different glycosylation methods have been developed that are based on the modulation effect of external nucleophiles. This review highlights the development, synthetic application, challenges and outlook of the modulated glycosylation methods.
Tuning Reactivity of Glycosyl Imidinium Intermediate for 2-Azido-2-deoxyglycosyl Donors in alpha-Glycosidic Bond Formation
(2013-10-18)
Ingle, Arun B.
;
Chao, Chin-Sheng
;
Hung, Wei-Cheng
;
Mong, Kwok-Kong Tony
;
應用化學系
The chemical properties of nucleophile additives were investigated in a modulated glycosylation context. N-Formylmorpholine (NFM) was found to be an effective modulator for glycosylation with less reactive 2-azido-2-deoxythioglucosyl and thiogalactosyl donors.