Three deinoxanthin analogs were found to bind the SDBC, suggesting a non-selective binding site of deinoxanthin in SDBC.2,4-Diamino-2,4,6-trideoxyglucose (bacillosamine) is a monosaccharide found in many pathogenic bacteria, variation in the functionalities appended to the amino groups occurs depending on the species the sugar is derived from. We here report the first synthesis of bacillosamine synthons that allow for the incorporation of two different functionalities at the C-2-N-acetyl and C-4-amines. We have developed chemistry to assemble a set of conjugation ready Neisseria meningitidis C-2-N-acetyl bacillosamine saccharides, carrying either an acetyl or (R)- or (S)-glyceroyl at the C-4 amine. The glyceroyl bacillosamines have been further extended at the C-3-OH with an α-d-galactopyranose to provide structures that occur as post-translational modifications of N. meningitidis PilE proteins, which make up the bacterial pili.The nutraceutical Nicotinamide Riboside (NR), an efficacious biosynthetic precursor to NAD, is readily metabolized by the purine nucleoside phosphorylase (PNP). https://www.selleckchem.com/products/pirtobrutinib-loxo-305.html Access to the PNP-stable versions of NR is difficult because the glycosidic bond of NR is easily cleaved. Unlike NR, NRH, the reduced form of NR, offers sufficient chemical stability to allow the successful functionalisation of the ribosyl-moiety. Here, we report on a series of NRH and NR derived amino acid conjugates, generated in good to excellent yields and show that O5'-esterification prevents the PNP-catalyzed phosphorolysis of these NR prodrugs.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.Recent studies have suggested that the anticancer activity of disulfiram (DSF, an FDA-approved alcohol-abuse drug) is Cu-dependent. Low system toxicity and explicit pharmacokinetic characteristics of DSF necessitate safe and effective Cu supplementation in local lesion for further applications. Herein, we presented a new conceptual 'nanosized coordination transport' strategy of Cu(ii) that was realized in porphyrin-based metal-organic frameworks, Sm-TCPP, with strong binding ability to Cu(ii) due to their coordination interactions. Sm-TCPP(Cu) was coated by hyaluronic acid (HA) that termed by Sm-TCPP(Cu)@HA, acting as 'beneficial horse' to target the tumor-localized HA receptor (CD44), thus liberating Cu(ii) ions in cellular overexpressed reductants. The CD44-mediated Cu(ii) accumulation efficiency of Sm-TCPP(Cu)@HA was benchmarked in vitro and vivo against the free TCPP (Cu) via ICP-MS analysis. More importantly, the sensitization effects of Sm-TCPP(Cu)@HA on the anticancer activity of DSF were demonstrated in vivo and in vitro. This study offered a new class of targeted Cu supplements to sensitize DSF for the effective treatment of cancer and established a versatile methodology for constructing a safe and specific delivery of metal ions within living organisms.We report a study where Car-Parrinello molecular dynamics simulations and variable-temperature (30-300 K) 1H spin-lattice relaxation time experiments nicely complement each other to characterize the dynamics within a set of four crystalline 1,4-diethynylbicyclo[2.2.2]octane (BCO) rotors assembled in the metal-organic rotor, Li+4(-CO2-Ph-BCO-py)4(H2O)8·2DMF. The remarkable finding of this work is that, despite the individual rotational barriers of four rotors being indiscernible and superimposed in a broad relaxation process, we were able to unravel a strongly interrelated series of rotational motions involving disrotatory and conrotatory motions in pairs as well as rotational steps of single rotators, all three processes with similar, sizeable rotational barriers of 6 kcal mol-1. It is noteworthy that DFT molecular dynamics simulations and variable-temperature (30-300 K) proton spin-lattice relaxation time experiments deliver the same high value for the rotational barriers stressing the potential of the combined use of the two techniques in understanding rotational motion at the nanoscale.A novel and mild Rh(iii)-catalyzed C-H activation/intramolecular condensation of 1-aryl-1H-pyrazol-5-amines with cyclic 2-diazo-1,3-diketones was developed, giving access to various important benzo[f]pyrazolo[1,5-a][1,3]diazepine scaffolds through sequential C-C/C-N bond formation in a one-pot procedure under additive- and oxidant-free conditions. Furthermore, 3-([1,1'-biphenyl]-2-ylamino)-2-ethoxycyclohex-2-enones can be obtained in good yields by constructing C-O and C-N bonds through 1,1'-insertion, dehydration, and isomerization processes.
Three deinoxanthin analogs were found to bind the SDBC, suggesting a non-selective binding site of deinoxanthin in SDBC.2,4-Diamino-2,4,6-trideoxyglucose (bacillosamine) is a monosaccharide found in many pathogenic bacteria, variation in the functionalities appended to the amino groups occurs depending on the species the sugar is derived from. We here report the first synthesis of bacillosamine synthons that allow for the incorporation of two different functionalities at the C-2-N-acetyl and C-4-amines. We have developed chemistry to assemble a set of conjugation ready Neisseria meningitidis C-2-N-acetyl bacillosamine saccharides, carrying either an acetyl or (R)- or (S)-glyceroyl at the C-4 amine. The glyceroyl bacillosamines have been further extended at the C-3-OH with an α-d-galactopyranose to provide structures that occur as post-translational modifications of N. meningitidis PilE proteins, which make up the bacterial pili.The nutraceutical Nicotinamide Riboside (NR), an efficacious biosynthetic precursor to NAD, is readily metabolized by the purine nucleoside phosphorylase (PNP). https://www.selleckchem.com/products/pirtobrutinib-loxo-305.html Access to the PNP-stable versions of NR is difficult because the glycosidic bond of NR is easily cleaved. Unlike NR, NRH, the reduced form of NR, offers sufficient chemical stability to allow the successful functionalisation of the ribosyl-moiety. Here, we report on a series of NRH and NR derived amino acid conjugates, generated in good to excellent yields and show that O5'-esterification prevents the PNP-catalyzed phosphorolysis of these NR prodrugs.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.Recent studies have suggested that the anticancer activity of disulfiram (DSF, an FDA-approved alcohol-abuse drug) is Cu-dependent. Low system toxicity and explicit pharmacokinetic characteristics of DSF necessitate safe and effective Cu supplementation in local lesion for further applications. Herein, we presented a new conceptual 'nanosized coordination transport' strategy of Cu(ii) that was realized in porphyrin-based metal-organic frameworks, Sm-TCPP, with strong binding ability to Cu(ii) due to their coordination interactions. Sm-TCPP(Cu) was coated by hyaluronic acid (HA) that termed by Sm-TCPP(Cu)@HA, acting as 'beneficial horse' to target the tumor-localized HA receptor (CD44), thus liberating Cu(ii) ions in cellular overexpressed reductants. The CD44-mediated Cu(ii) accumulation efficiency of Sm-TCPP(Cu)@HA was benchmarked in vitro and vivo against the free TCPP (Cu) via ICP-MS analysis. More importantly, the sensitization effects of Sm-TCPP(Cu)@HA on the anticancer activity of DSF were demonstrated in vivo and in vitro. This study offered a new class of targeted Cu supplements to sensitize DSF for the effective treatment of cancer and established a versatile methodology for constructing a safe and specific delivery of metal ions within living organisms.We report a study where Car-Parrinello molecular dynamics simulations and variable-temperature (30-300 K) 1H spin-lattice relaxation time experiments nicely complement each other to characterize the dynamics within a set of four crystalline 1,4-diethynylbicyclo[2.2.2]octane (BCO) rotors assembled in the metal-organic rotor, Li+4(-CO2-Ph-BCO-py)4(H2O)8·2DMF. The remarkable finding of this work is that, despite the individual rotational barriers of four rotors being indiscernible and superimposed in a broad relaxation process, we were able to unravel a strongly interrelated series of rotational motions involving disrotatory and conrotatory motions in pairs as well as rotational steps of single rotators, all three processes with similar, sizeable rotational barriers of 6 kcal mol-1. It is noteworthy that DFT molecular dynamics simulations and variable-temperature (30-300 K) proton spin-lattice relaxation time experiments deliver the same high value for the rotational barriers stressing the potential of the combined use of the two techniques in understanding rotational motion at the nanoscale.A novel and mild Rh(iii)-catalyzed C-H activation/intramolecular condensation of 1-aryl-1H-pyrazol-5-amines with cyclic 2-diazo-1,3-diketones was developed, giving access to various important benzo[f]pyrazolo[1,5-a][1,3]diazepine scaffolds through sequential C-C/C-N bond formation in a one-pot procedure under additive- and oxidant-free conditions. Furthermore, 3-([1,1'-biphenyl]-2-ylamino)-2-ethoxycyclohex-2-enones can be obtained in good yields by constructing C-O and C-N bonds through 1,1'-insertion, dehydration, and isomerization processes.
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