Robust induction of cancer-antigen-specific CD8 T cells is essential for the success of cancer peptide vaccines, which are composed of a peptide derived from a cancer-specific antigen and an immune-potentiating adjuvant, such as a Toll-like receptor (TLR) agonist. Efficient delivery of a vaccine antigen and an adjuvant to antigen-presenting cells in the draining lymph nodes (LNs) holds key to maximize vaccine efficacy. Here, we developed S-540956, a novel TLR9-agonistic adjuvant consisting of B-type CpG ODN2006 (also known as CpG7909), annealed to its complementary sequence oligodeoxynucleotide (ODN) conjugated to a lipid; it could target both a cancer peptide antigen and a CpG-adjuvant in the draining LNs.
View Article and Find Full Text PDFAntibiotic-resistant bacterial infection is a serious threat to public health. Peptidoglycan biosynthesis is a well-established target for antibiotic development. MraY (phospho-MurNAc-pentapeptide translocase) catalyses the first and an essential membrane step of peptidoglycan biosynthesis.
View Article and Find Full Text PDFIt is urgent to develop novel anti-Pseudomonas agents that should also be active against multidrug resistant P. aeruginosa. Expanding the antibacterial spectrum of muraymycins toward P.
View Article and Find Full Text PDFThe systematic structure-activity relationship (SAR) of the muraymycins (MRYs) using an Ugi four-component reaction (U4CR) was investigated. The impact of the lipophilic substituent on antibacterial activity was significant, and the analogues 8 and 9 having a lipophilic side chain exhibited good activity against a range of Gram-positive bacterial pathogens, including MRSA and VRE. Further investigation of compounds 8 and 9 revealed these analogues to be selective inhibitors of the MraY transferase and nontoxic to HepG2 cells.
View Article and Find Full Text PDFThe L-epi-capreomycidine (Cpm) derivatives were efficiently and stereoselectively synthesized via nitrene C-H insertion starting from a readily available D-Tyr. Design of a substrate that takes into account hydrogen bonding is a critical feature in order to achieve high selectivity. Our synthetic strategy could be a new access to epi-Cpm and its derivatives, which are found in several biologically active natural products.
View Article and Find Full Text PDFThis review describes the synthesis and structure-activity relationship (SAR) study of muraymycins (MRYs), which are potent antibacterial nucleoside antibiotics. The key elements of our synthetic approach include the preparation of L-epi-capreomycidine via a C-H amination reaction and a convergent assemblage to construct of the framework of MRYs using Ugi four component reaction. With this approach the first total synthesis of MRY D2 and its epimer, epi-MRY D2, which does not have lipophilic substituents, has been accomplished.
View Article and Find Full Text PDFMuraymycin analogues with a lipophilic substituent were synthesized using an Ugi four-component assemblage. This approach provides ready access to a range of analogues simply by altering the aldehyde component. The impact of the lipophilic substituent on the antibacterial activity was very large, and analogues 7b-e and 8b-e exhibited good activity against a range of Gram-positive bacterial pathogens including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium.
View Article and Find Full Text PDFSulfotransferases are involved in a variety of physiological processes and typically use 3'-phosphoadenosine 5'-phosphosulfate (PAPS) as the sulfate donor substrate. In contrast, microbial arylsulfate sulfotransferases (ASSTs) are PAPS-independent and utilize arylsulfates as sulfate donors. Yet, their genuine acceptor substrates are unknown.
View Article and Find Full Text PDFFull details of the first total synthesis of (-)-muraymycin (MRY) D2 and its epimer, the antibacterial nucleoside natural product, are described. Key strategic elements of the approach include the preparation of the urea dipeptide moiety found in the muraymycins containing an L-epi-capreomycidine via a nitrene C-H insertion of the sulfamate 10 and the fully protected muraymycin skeleton at a late stage by an Ugi four-component reaction. Thus, the nitrene C-H insertion of the sulfamate 10 with 10 mol % of Rh(2)(esp)(2) catalyst gave the cyclic sulfamates 11a and 11b in 47% yield (11a:11b = 1:2.
View Article and Find Full Text PDFNucleic Acids Symp Ser (Oxf)
November 2010
The synthetic study of muraymycins (MRYs), which have potent antibacterial activity, is described. The key elements of our approach include the synthesis of L-epicapreomycidine via a C-H amination reaction and a conversient assemblage to construct of the framework of muraymycins using Ugi-four component reaction. First, isonitrile 4 was prepared from uridine in 14 steps.
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