Hideki Hashizume

Learn More
Since the late 20th century, the prevalence of infectious diseases caused by the drug-resistant bacteria, especially by the Gram-positive ones has become a serious problem in the medical treatments, rendering the major antimicrobial drugs less active or ineffective against many important bacterial infections1,2). Thus the newer drugs effective against the(More)
Peptide antibiotics tripropeptins A, B, C, D and Z were isolated from cultured cells and broth of Lysobacter sp. The differences among these components are in the lengths of the alkyl side chain. Tripropeptins are active against Gram-positive bacteria including MRSA in vitro. Bactericidal activity of tripropeptin C disappeared in the simultaneous presence(More)
BACKGROUND The development and activation of CD4+ helper T cell (Th) subsets with distinct patterns of unbalanced production of cytokines play an important part in infectious, allergic and autoimmune diseases. Human neonatal cord blood CD4+ Th cells can be polarized into type 1 or type 2-like effector cells in vitro by culturing them in the presence of(More)
Tripropeptin C (TPPC) is a naturally occurring cyclic lipodepsipeptide antibiotic produced by a Lysobacter sp. TPPC exhibits potent antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and penicillin-resistant Streptococcus pneumoniae. This antibiotic also inhibits the incorporation of(More)
Branched chain amino acids are often utilized as the precursors of many lipid-containing bacterial secondary metabolites. The effect of isoleucine on the composition of the mixture of cyclic lipopeptide antibiotics, tripropeptins from Lysobacter sp. BMK333-48F3 was evaluated. As expected, a novel tripropeptin analog with an anteiso-branched fatty acid was(More)
Planar structures of tripropeptins (TPPs) were elucidated by spectroscopic studies including various NMR measurements. Stereochemistry of constituent amino acids of tripropeptin C (TPPC) (3) was identified by marfey's method except hydroxyproline which was determined by studies of NMR and CD spectra. The absolute structure of 3 was determined by analyses of(More)
Tripropeptin C (TPPC) is a natural calcium-ion-dependent lipopeptide antibiotic that inhibits peptidoglycan biosynthesis by binding to prenyl pyrophosphate. It displays very potent antimicrobial activity both in vitro and in a mouse model of methicillin-resistant Staphylococcus aureus (MRSA) septicemia. The combination of TPPC with all classes of(More)
The biosynthetic pathway leading to the cyclitol moiety of pyralomicin 1a (1) in Nonomuraea spiralis MI178-34F18 has been studied using a series of 2H-labeled potential precursors. The results demonstrate that 2-epi-5-epi-valiolone (7), a common precursor for acarbose (4) and validamycin A (5) biosynthesis, is an immediate precursor of pyralomicin 1a.(More)
The staphylococcal superantigen-like protein (SSL) family is composed of 14 exoproteins sharing structural similarity with superantigens but no superantigenic activity. Target proteins of four SSLs have been identified to be involved in host immune responses. However, the counterparts of other SSLs have been functionally uncharacterized. In this study, we(More)