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Chemiluminescence (CL), as one class of luminescence driven by chemical reaction, exhibits obvious temperature-dependence in its light emission process. Herein, temperature-dependent CL emission of carbon nanodots (CDs) in the chemical reaction of peroxalate and hydrogen peroxide is demonstrated and temperature imaging based on the temperature-dependent CL has been established for the first time. In detail, the temperature-dependent CL emission of CDs in the chemical reaction of peroxalate and hydrogen peroxide is observed, and the linear relationship between the CL intensity and temperature is demonstrated in both the CL solution and film, enabling their applications in temperature sensing and imaging capabilities. The increase of the CL emission with temperature can be attributed to the accelerated electron exchange between the CDs and intermediate generated in the peroxalate system. Meter-scale chemiluminescent CD films have been constructed. The CL sensor based on the films presents a high spatial resolution of 0.4 mm and an outstanding sensitivity of 0.08 °C

A high-quality 2-inch polycrystalline diamond was prepared by MPCVD technique. Photodetector planar arrays were then fabricated from the polycrystalline diamond. Clear solar-blind images have been obtained using the arrays as the sensing unit.

Three new phenylpropenoid glycosides (1–3), and five undescribed shikimic acid derivatives (4–8), together with six known analogues (9–14), were obtained from the dried leaves of Illicium dunnianum.

Globo H is a tumor-associated carbohydrate antigen (TACA), which serves as a valuable target for antitumor vaccine or cancer immunotherapies. However, most TACAs are T-cell-independent, and they cannot induce powerful immune response due to their poor immunogenicity. To address this problem, herein, several Globo H analogues with modification on the N-acyl group were prepared through a preactivation-based glycosylation strategy from the non-reducing end to the reducing end. These modified Globo H derivatives were then conjugated with carrier protein CRM197 to form glycoconjugates as anticancer vaccine candidates, which were used in combination with adjuvant glycolipid C34 for immunological studies. The immunological effects of these synthetic vaccine candidates were evaluated on Balb/c mice. The results showed that the fluorine-modified N-acyl Globo H conjugates can induce higher titers of IgG antibodies that can recognize the naturally occurring Globo H antigen on the surface of cancer cells and can eliminate cancer cells in the presence of a complement, indicating the potential of these synthetic glycoconjugates as anticancer vaccine candidates.

A new glycosylation method promoted by visible light with 3,5-dimethoxyphenyl glycoside as the donor was developed. This protocol delivers both O-glycosides and N-glycosides in moderate to excellent yields using a wide range of O-nucleophiles and nucleobases as the glycosyl acceptors.

Terminal α-2,6-sialylation of N-glycans is a humanized glycosylation that affects the properties and efficacy of therapeutic glycoproteins. Fc di-sialylation (a biantennary N-glycan with two α-2,6-linked sialic acids) of IgG antibodies imparts them with enhanced anti-inflammatory activity and other roles. However, the microheterogeneity of N-glycoforms presents a challenge for therapeutic development. Therefore, controlled sialylation has drawn considerable attention, but direct access to well-defined di-sialylated antibodies remains limited. Herein, a one-pot three-enzyme protocol was developed by engineering a bacterial sialyltransferase to facilitate the modification of therapeutic antibodies with N-acetylneuraminic acid or its derivatives towards optimized glycosylation. To overcome the low proficiency of bacterial sialyltransferase in antibody remodeling, the Photobacterium sp. JT-ISH-224 α-2,6-sialyltransferase (Psp2,6ST) was genetically engineered by terminal truncation and site-directed mutagenesis based on its protein crystal structure. With the optimized reaction conditions and using activity-based screening of various Psp2,6ST variants, a truncated mutant Psp2,6ST (111-511)-His6 A235M/A366G was shown to effectively improve the catalytic efficiency of antibody di-sialylation. Herceptin and the donor substrate promiscuity allow the introduction of bioorthogonal modifications of N-acetylneuraminic acid into antibodies for site-specific conjugation. 2-AB hydrophilic interaction chromatography analysis of the released N-glycans and intact mass characterization confirmed the high di-sialylation of Herceptin via the optimized one-pot three-enzyme reaction. This study established a versatile enzymatic approach for producing highly di-sialylated IgG antibodies. It provides new insights into engineering bacterial sialyltransferase for adaptation to the enzymatic glycoengineering of therapeutic antibodies and the glycosite-specific conjugation of antibodies.

The C-glycosylation of C-nucleophiles including allyltrimethylsilane, silyl enol ethers and phenols with N-(glycosyloxy)acetamides as glycosyl donors has been realized. This protocol provides a convenient and practical route for the synthesis of alkyl C-glycosides and aryl 2-deoxy-β-C-glycosides under mild reaction conditions.

The synthesis of tumor-associated KH-1 antigen core nonasaccharide was achieved. All key glycosidic linkages were efficiently constructed by photo-induced glycosylation. The success of this total synthesis provides an example for the preparation of complex oligosaccharides using light-driven glycosylation reactions.

A new glycosylation protocol based on 2′-benzoylphenyl glycosides has been developed. These glycosyl donors could be rapidly activated by TfOH at room temperature. The donors are readily available. The reaction exhibited a broad substrate scope and coupled products were obtained in high yields.

Vi antigen is the capsular polysaccharide of Salmonella typhi, which can cause typhoid fever. With the increasing threat of antiboitic resistance, vaccination against Salmonella typhi is a preferred way to prevent this disease. Chemical synthesis of fragments of Vi antigen is in urgent need for the development of structure-homogeneous and quality-controlled oligosaccharide vaccines. However, it is extremely challenging to synthesize large oligosaccharide fragments of Vi antigen owing to the exclusive α-1,4-linkage of polyaminogalacturonates. Herein, a series of Vi oligosaccharides ranging from pentamer to octamer were efficiently prepared using 2,3-N,O-oxazolidinone protected glycosides as building blocks based on the preactivation protocol. The heptasaccharide and octasaccharide fragments were synthesized for the first time. The competitive ELISA evaluation suggested that the hexasaccharide might be the minimum epitope of Vi antigen, which provides a significant guidance for the future development of Vi oligosaccharide vaccines.

X-ray detectors are demonstrated using composite films of lead-free Cs2AgBiBr6 halide double perovskite embedded in a polymer matrix as the X-ray photoconductors. Polymers with hydroxyl functional groups greatly improve the uniformity of the composite films, and large area dense films are obtained using a simple drop-casting process. X-ray detectors based on the composite films exhibit a sensitivity of 40 μC Gyair−1 cm−2, comparable to the reported sensitivity using Cs2AgBiBr6 single crystals. Such detectors can also tolerate a 5% tensile/compressive strain in the composite films without performance degradation. Pixelated X-ray detectors fabricated on the same composite film can realize X-ray imaging and resolve a proof-of-concept geometric pattern.

Since the immunosuppressive agents currently used in clinics have significant side effects, it is very important to search for new effective and safe immunosuppressants. Iminosugars as a new class of immunosuppressants are less explored. In this report, 24 new N-arylated iminosugar derivatives, including d-talo and d-galacto epimers, were designed and synthesized, and their immunosuppressive effects were evaluated by MTT assay. The experimental data demonstrated that compound 20 showed the strongest inhibition effect (IC50 = 6.94 μM). Further studies revealed that the inhibitory effects on splenocyte proliferation may come from the suppression of both IFN-γ and IL-4 cytokines. The preliminary structure-activity relationship (SAR) analysis suggested that N-arylated d-galacto-type iminosugars showed better inhibitory activities than d-talo-type analogues. The SAR analysis also showed that the inhibition effect of iminosugars can be improved by decreasing the polarity or increasing the hydrophobicity. These results may be beneficial to the discovery of new iminosugar derivatives as immunosuppressive agents.

Glycoprotein MUC1 is an attractive target for anti-tumor vaccine development. However, the weak immunogenicity of MUC1 remains a significant problem. To solve this problem, several STn derivatives with N-acetyl modifications were synthesized and incorporated into a 20-amino acid MUC1 tandem repeat sequence. The modified STn-MUC1 glycopeptides were further connected to a carrier protein keyhole limpet hemocyanin (KLH). The immunological effects of these synthetic vaccine conjugates were evaluated using the BALB/c mouse model. The results showed that vaccine V2 elicited higher titers of antibodies which cross-reacted with the native STn-MUC1 antigen. Moreover, the elicited antisera reacted with the STn-MUC1 antigen-positive tumor cells, indicating that the carbohydrate antigen modification strategy may hold potential to overcome the weak immunogenicity of natural MUC1 glycopeptides.

Glycosylation is unarguably the most important reaction in the field of glycochemistry. Photo-initiated reactions hold extraordinary potential in organic synthesis. Herein we report a novel light-driven strategy for the activation of thioglycosides via the merger of a CF3 radical pathway followed by the subsequent glycosylation with glycosyl acceptors. This protocol could efficiently activate thioglycosides, thereby greatly enhancing the substrate scope of reactions. In particular, the glycosylation reactions, which are completely inert under the existing photo-induced glycosylation conditions, proceeded smoothly in high yields. Many common protective groups were well tolerated under the coupling conditions. Both UV and visible light or even sunlight were used as the source of light for the reactions. The high efficiency of this light-driven glycosylation protocol was further highlighted by the rapid one-pot sequential assembly of oligosaccharides.

Novel indolo-quinoline compounds were efficiently prepared via a Povarov-type reaction, and the structures were further modified by a Suzuki coupling reaction. The corresponding BF2-rigidified complexes were prepared and their spectroscopic properties were characterized with large Stokes shifts (up to 211 nm) and up to near-infrared (NIR) wavelength (667 nm). The synthetic complexes could be used as new fluorescent dyes.

It is well known that tumor cells express some aberrant glycans, termed tumor-associated carbohydrate antigens (TACAs). TACAs are good targets for the development of carbohydrate-based anticancer vaccines. However, one of the major problems is that carbohydrate antigens possess a weak immunogenicity. To tackle this problem, a number of unnatural N-modified S-linked STn analogues were designed and prepared. Reaction of the modified STn disaccharides with bifunctional adipic acid p-nitrophenyl diester provided the corresponding activated esters, which was followed by the conjugation with keyhole limpet hemocyanin (KLH), affording the corresponding protein conjugates. The immunological properties of these glycoconjugates were evaluated in a mouse model. The results showed that the modified glycoconjugates stimulated the production of IgG antibodies that are capable of recognizing the naturally occurring STn antigen, helping the discovery of carbohydrate-based anticancer vaccine candidates.

ManNAc analogues are important chemical tools for probing sialylation dynamically via metabolic oligosaccharide engineering (MOE). The size of N-acyl and the nature of the chemical handle are two determinants of metabolic incorporation efficiency. We demonstrated a minimal, stable, bioorthogonal, and reactive N-Cp (N-(cycloprop-2-ene-1-ylcarbonyl)) group and the imaging of sialylated glycans using Ac4ManNCp in vitro and in vivo. The results revealed that the Cp group can efficiently be incorporated into the cellular sialic acid and detected rapidly by the reaction with FITC-Tz in different cells. The metabolic incorporation efficiency of non-cytotoxic Ac4ManNCp is not only superior to Ac4ManNMCp, but also superior to the widely-used Ac4ManNAz in some cell lines. Moreover, when Ac4ManNCp was administered to mice, a rapid and intense labelling of splenocytes as well as glycoproteins of sera and organs was observed. This is the first reported metabolic labelling of cyclopropene-modified sugars in vivo. Therefore, Ac4ManNCp is a powerful probe for efficient and rapid MOE and it may find wide applications in the labelling of glycans.

Twelve novel N-dialkylphosphoryliminosugar derivatives were synthesized and their immunosuppressive activities were evaluated on the proliferation of the mouse splenocytes and the secretion of IFN-γ and IL-4. The experimental data demonstrated that the iminosugars with the double long alkyl chains exhibited better inhibitory effects than those with the single long alkyl chain, and the iminosugars with the 10-carbon linear alkyl chain exhibited the strongest immunosuppressive activities. The assay of the cytokine secretion showed that the introduction of dialkyl chains on iminosugars could regulate the polarization of immune inhibition by varying the length of the alkyl chains. The disclosure of the structure-activity relationships may benefit the structural modifications of iminosugars to find new types of immunosuppressive agents.

An approach to the regio- and stereo-selective construction of 2-deoxy-C-glycosides via Lewis acid-mediated rearrangement of 2,3-anhydro-1-thiopyranosides is disclosed. Treatment of 2,3-anhydro-1-thiopyranosides with phenols in the presence of TMSOTf, the migration–O-glycosylation and Fries-like O to C rearrangement took place in succession, providing aryl 2-thio-2-deoxy-C-glycosides with the single thermodynamically favourable configuration (1C4 or 4C1) in good to excellent yields. The coupling reaction of 2,3-anhydro-1-thiopyranosides with trimethylsilylated or tributylstanylated nucleophiles in the presence of TMSOTf or Sc(OTf)3, via the migration–C-glycosylation process, afforded 2-thio-2-deoxy-C-glycosides in a stereospecific manner in moderate to good yields and with the C-1 and C-2 substituents opposite. The 2-thio-functionality was further removed to produce the corresponding 2-deoxy-C-glycosides. This method may provide a convenient route for the preparation of 2-deoxy-C-glycosides.

O,O-Dimethylthiophosphonosulfenyl bromide (DMTPSB) in combination with silver triflate provides a powerful thiophilic promoter system. Both "armed" and "disarmed" thioglycoside glycosyl donors can be activated to form glycosidic linkages efficiently by the pre-activation protocol. The usefulness of this new promoter is illustrated by a successful iterative one-pot oligosaccharide assembly.

Correction for ‘Light-driven highly efficient glycosylation reactions’ by Run-Ze Mao et al., Org. Chem. Front., 2016, DOI: 10.1039/c6qo00021e.

A new class of dinuclear cyclometalated platinum(II) complexes with [PtII(C^N^N)CNR]+ (HC^N^N = 6-phenyl-2,2′-bipyridyl, CNR = 2,6-dimethylphenyl isocyanide) motifs covalently connected by oligo(oxyethylene) chains form luminescent lyotropic chromonic liquid crystals or hydrogels in aqueous dispersions with intra- and intermolecular Pt⋯Pt and π–π interactions as the driving force. Their solution behaviour is modulated by the length of the oligo(oxyethylene) chain connecting the two cyclometalated platinum(II) motifs. One of the dinuclear Pt(II) complexes with a long oligo(oxyethylene) bridge and which does not display intramolecular Pt⋯Pt and π–π interactions can act as an effective ‘gelling stimulus’ for mononuclear [PtII(C^N^N)CNR]+ complexes in aqueous solutions, resulting in the formation of a nematic hydrogel that is persistent and displays red photoluminescence.

Novel pancake-like Cd(OH)2 superstructures have been prepared via a facile and rapid microwave-assisted hydrothermal method, employing cadmium acetate and hydrazine hydrate as the starting materials in a mixed medium of water and glycerol. Several influencing factors, such as the volume of hydrazine hydrate and glycerol, the reaction time, temperature and cadmium source, were found to play important roles in the formation of the Cd(OH)2 multilayer stacked structures. Experiments suggested that the layer-by-layer self-assembly of nanosheets is responsible for the formation of these superstructures. Moreover, the as-obtained Cd(OH)2 superstructures show an enhanced photocatalytic activity for the decomposition of rhodamine B (RhB) under basic conditions.