A new polyene macrolide antibiotic, machidamycin, produced by Streptomyces sp. K22-0017.

A new polyene macrolide, machidamycin (1), and a known compound YS-822A (2), were obtained by physicochemical screening from a culture broth of Streptomyces sp. K22-0017. The structures were elucidated using MS and 1D/2D NMR analyses.

Akedanones A-C, and Antiplasmodial 2,3-Dihydronaphthoquinones Produced by sp. K20-0187.

Three new antiplasmodial compounds, named akedanones A (), B (), and C (), were discovered from the cultured material of sp. K20-0187 isolated from a soil sample collected at Takeda, Kofu, Yamanashi prefecture in Japan. The structures of compounds - were elucidated as new 2,3-dihydronaphthoquinones having prenyl and reverse prenyl groups by mass spectrometry and nuclear magnetic resonance analyses.

A new tetronomycin analog, broad-spectrum and potent antibiotic against drug-resistant Gram-positive bacteria.

We discovered a new tetronomycin analog, C-32-OH tetronomycin (2) from the Streptomyces sp. K20-0247 strain, which produces tetronomycin (1). After NMR analysis of 2, we determined the planar structure.

Design and Synthesis of d-Ala-d-Ala Silica Gel for a Binding Mode-Based Physicochemical Screening Method.

Vancomycin is a potent and broad-spectrum antibiotic that binds to the d-Ala-d-Ala moiety of the growing bacterial cell wall and kills bacteria. This fascinating binding model prompted us to design and synthesize d-Ala-d-Ala silica gels for the establishment of a new physicochemical (PC) screening method. In this report, we confirmed that vancomycin binds to d-Ala-d-Ala silica gel and can be eluted with MeOH containing 50 mM TFA.

Emblestatin: a new peptide antibiotic from Embleya scabrispora K20-0267.

A new peptide, emblestatin (1), was discovered from a culture broth of Embleya scabrispora K20-0267. This strain was isolated from soil using an agar medium containing lysozyme. Based on NMR and mass spectrometric analyses, 1 consists of 2-(2-hydroxyphenyl)-2-oxazoline, β-alanine, glutamine, N-methyl-N-hydroxyornithine and 3-amino-1-hydroxy-2-piperidone moieties.

Rediscovery of Tetronomycin as a Broad-Spectrum and Potent Antibiotic against Drug-Resistant Gram-Positive Bacteria.

Tetronomycin (), first isolated from a cultured broth of sp. by Juslen . in 1974, is a polycyclic polyether compound.

Comprehensive analysis of biosynthetic gene clusters in bacteria and discovery of Tumebacillus as a potential producer of natural products.

Limited microbial genera such as Streptomyces have served as sources of natural products (NPs), whereas most others have been less investigated. The vast accumulation of genomic data available in the NCBI database enables us to bioinformatically estimate the ability of other microbial groups to produce NPs. We analyzed 21,052 complete bacterial genome sequences using antiSMASH and compared the average numbers of biosynthetic gene clusters (BGCs) related to polyketides, non-ribosomal peptides, and/or terpenes biosynthesis at the genus level.

Enzymatic synthesis of non-natural flavonoids by combining geranyl pyrophosphate C6-methyltransferase and aromatic prenyltransferase.

Terpenoids are the largest class of natural products and are derived from C5 isoprene units. Recent discoveries of modification enzymes in native isoprene units before cyclization or transfer reactions have revealed that C5 units with additional carbon atoms are also used to produce terpenoids. These reports indicate that the utilization of these modification enzymes is useful for the enzymatic production of non-natural terpenoids.

Insights into the structure-activity relationship of a type III secretion system inhibitor, aurodox.

Aurodox was originally isolated in 1972 as a linear polyketide compound exhibiting antibacterial activity against Gram-positive bacteria. We have since identified aurodox as a specific inhibitor of the bacterial type III secretion system (T3SS) using our original screening system for inhibition of T3SS-mediated hemolysis in enteropathogenic Escherichia coli (EPEC). In this research, we synthesized 15 derivatives of aurodox and evaluated EPEC T3SS inhibitory activity as well as antibacterial activity against EPEC.

Identification and Analysis of the Biosynthetic Gene Cluster for the Indolizidine Alkaloid Iminimycin in Streptomyces griseus.

Indolizidine alkaloids, which have versatile bioactivities, are produced by various organisms. Although the biosynthesis of some indolizidine alkaloids has been studied, the enzymatic machinery for their biosynthesis in Streptomyces remains elusive. Here, we report the identification and analysis of the biosynthetic gene cluster for iminimycin, an indolizidine alkaloid with a 6-5-3 tricyclic system containing an iminium cation from Streptomyces griseus.

Structural and Molecular Basis of the Catalytic Mechanism of Geranyl Pyrophosphate C6-Methyltransferase: Creation of an Unprecedented Farnesyl Pyrophosphate C6-Methyltransferase.

Prenyl pyrophosphate methyltransferases enhance the structural diversity of terpenoids. However, the molecular basis of their catalytic mechanisms is poorly understood. In this study, using multiple strategies, we characterized a geranyl pyrophosphate (GPP) C6-methyltransferase, BezA.

Unprecedented Cyclization Catalyzed by a Cytochrome P450 in Benzastatin Biosynthesis.

Benzastatins have unique structures probably derived from geranylated p-aminobenzoic acids. The indoline and tetrahydroquinoline scaffolds are presumably formed by cyclization of the geranyl moiety, but the cyclization mechanism was unknown. We studied the benzastatin biosynthetic gene cluster of Streptomyces sp.