On the chiroptical properties of Au(i)–thiolate glycoconjugate precursors and their influence on sugar-protected gold nanoparticles (glyconanoparticles)
“…Thus, based on our results, we think that the glycans conjugated to OVA through lysine residues or the N-terminus do not affect the overall reductive potential of glycoproteins and further formation of clusters at the tested valencies [ 36 ]. Additionally, sugars seem not to hamper formation of cluster-stabilizing Au (I) thiolate polymers [ 37 , 38 ] between the cysteine groups of protein and gold core, even when present in higher number (5–6 copies). Fig.…”
Carbohydrate-protein interactions mediate fundamental biological processes, such as fertilization, cell signaling, or host-pathogen communication. However, because of the enormous complexity of glycan recognition events, new tools enabling their analysis or applications emerge in recent years. Here, we describe the first preparation of neoglycoprotein functionalized fluorescent gold nanoclusters, containing a biantennary N-glycan G0 as targeting molecule, ovalbumin as carrier/model antigen, and a fluorescent gold core as imaging probe (G0-OVA-AuNCs). Subsequently, we demonstrate the utility of generated G0-OVA-AuNCs for specific sensing of plant lectins and in vitro imaging of dendritic cells.Electronic supplementary materialThe online version of this article (10.1186/s11671-018-2772-2) contains supplementary material, which is available to authorized users.
“…Thus, based on our results, we think that the glycans conjugated to OVA through lysine residues or the N-terminus do not affect the overall reductive potential of glycoproteins and further formation of clusters at the tested valencies [ 36 ]. Additionally, sugars seem not to hamper formation of cluster-stabilizing Au (I) thiolate polymers [ 37 , 38 ] between the cysteine groups of protein and gold core, even when present in higher number (5–6 copies). Fig.…”
Carbohydrate-protein interactions mediate fundamental biological processes, such as fertilization, cell signaling, or host-pathogen communication. However, because of the enormous complexity of glycan recognition events, new tools enabling their analysis or applications emerge in recent years. Here, we describe the first preparation of neoglycoprotein functionalized fluorescent gold nanoclusters, containing a biantennary N-glycan G0 as targeting molecule, ovalbumin as carrier/model antigen, and a fluorescent gold core as imaging probe (G0-OVA-AuNCs). Subsequently, we demonstrate the utility of generated G0-OVA-AuNCs for specific sensing of plant lectins and in vitro imaging of dendritic cells.Electronic supplementary materialThe online version of this article (10.1186/s11671-018-2772-2) contains supplementary material, which is available to authorized users.
“…So far, most of the efforts toward the development of optically active nanostructures have been focused on single-component systems, especially thiolated chiral molecules capping gold clusters; ,− however, compared with single-component systems, alloy metal NPs often demonstrate unique stability, leading to enhanced chemical, catalytic, and optical properties. − Thus, in this study, as a test case for chiral alloy nanoparticle synthesis, optically active ultrafine Au–Ag alloy NPs were attempted to be synthesized via reduction of different molar fractions of HAuCl 4 and AgNO 3 by employing NaBH 4 as the reducing agent and d / l -penicillamine ( d / l -Pen) as the capping agent. Further, according to the report by Nishida et al, the chiroptical response of the silver NCs is several-fold larger than that of the gold NCs having the same ligand; therefore, to gain insight into the alloying effect on the chiroptical activity, the chiroptical behavior of bimetallic Au–Ag NPs was compared with those of monometallic Au and Ag counterparts with comparable size.…”
Despite a significant surge in the number of investigations into chirality at the nanoscale, especially thiolated chiral molecules capping gold clusters, only limited knowledge is currently available to elaborate the alloying effect on chiroptical behavior of bimetallic nanoparticles (NPs). Also, few successful cases as to the efforts toward the development of chirality-dependent applications on the optically active nanomaterial have been made. Herein, as a positive test case for chiral alloy nanoparticle synthesis, the stable and large chiroptical ultrafine Au-Ag alloy NPs were prepared by reduction of different molar fractions of HAuCl and AgNO with NaBH in the presence of d/l-penicillamine (d/l-Pen). Compared with those of monometallic Au and Ag counterparts with comparable size, the Au-Ag alloy NPs (Ag mole fraction, 70%) obviously displayed the largest optical activities with the maximum g-factors of ∼1.6 × 10. Impressively, the Pen-mediated synthesis of chiral Au-Ag alloy NPs possesses a colorimetric self-recognition function and can be used as an incisive circular dichroism (CD) probe toward d- and l-Pen enantiomers. The plasmonic CD signal amplification (ΔI) shows good linearity with the amount of Pen over the range of 5.0-80.0 μM with a detection limit (3σ) of 1.7 μM for l-Pen and 1.5 μM for d-Pen, respectively. In addition, the sensing system exhibits good selectivity toward d- and l-Pen in the presence of other enantiomers; therefore, it is highly expected that the approach described here would open new opportunities for design of more novel enantioselective analyses of important species related to biological processes.
“…To further prove the formation of heptenitols and acyl group migration, benzoylation/acetylation of the corresponding compounds under standard conditions were carried out. Benzoylation [47] of the mixture of heptenitols 3 and 4 resulted in a single product 11 (Table 4) while acetylation [48] of heptenitol 9 gave O-peracetylated product 12 in good to excellent yields (Scheme 3). The NMR analysis provided evidence for the structure of all of the above derivatives and these are illustrated here by the examples of compounds 2, 3, and 4.…”
Section: Ementioning
confidence: 99%
“…To further prove the formation of heptenitols and acyl group migration, benzoylation/acetylation of the corresponding compounds under standard conditions were carried out. Benzoylation [47] of the mixture of heptenitols 3 and 4 resulted in a single product 11 (Table 4) while acetylation [48] of heptenitol 9 gave O-peracetylated product 12 in good to excellent yields (Scheme 3). To get an insight into the effect of hydrolytically resistant ether type protecting groups on the outcome of the studied coupling reactions, O-permethylated (β-D-glucopyranosyl)formaldehyde tosylhydrazone 17 was synthesized.…”
A catalyst-free coupling reaction between O-peracetylated, O-perbenzoylated, O-permethylated, and O-permethoxymethylated 2,6-anhydro-aldose tosylhydrazones (C-(β-D-glycopyranosyl)formaldehyde tosylhydrazones) and aromatic boronic acids is reported. The base-promoted reaction is operationally simple and exhibits a broad substrate scope. The main products in most of the transformations were open-chain 1-C-aryl-hept-1-enitol type compounds while the expected β-D-glycopyranosylmethyl arenes (benzyl C-glycosides) were formed in subordinate yields only. A mechanistic rationale is provided to explain how a complex substrate may change the well-established course of the reaction.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
