Naphthomycins L–N, Ansamycin Antibiotics from <i>Streptomyces</i> sp. CS

Previous analyses of the naphthomycin biosynthetic gene cluster and a comparison with known naphthomycin-type products from <i>Streptomyces</i> sp. CS have suggested that new products can be found from this strain. In this study, screening by LC-MS of <i>Streptomyces</i> sp. CS products formed under different culture conditions revealed several unknown peaks in the product spectra of extracts derived from oatmeal medium cultures. Three new naphthomycins, naphthomycins L (<b>1</b>), M (<b>2</b>), and N (<b>3</b>), and the known naphthomycins A (<b>4</b>), E (<b>5</b>), and D (<b>6</b>) were obtained. The structures were elucidated using spectroscopic data from 1D and 2D NMR and HRESIMS experiments

Functional classification of unique <i>S. chinensis</i> ESTs according to the MIPS Functional Catalogue scheme.

<p>Functional classification of unique <i>S. chinensis</i> ESTs according to the MIPS Functional Catalogue scheme.</p

Validation of microarray results by qRT-PCR for selected genes (EG530711 <i>(ScPI-B)</i>, EH662329 <i>(ScAP3-B)</i>, EG530714 <i>(ScSEP1-like)</i>, EG530715, EG530716 <i>(ScAGL6)</i>, D945 <i>(ScAG-like)</i>, D1420 <i>(ScAP1-like)</i> and EG530713).

<p><i>S. chinensis α-TUBULIN</i> (JK704891) was used as an internal control for normalization of the template cDNA. Each independent experiment was performed three reactions, and the error bars represent the standard deviation of three independent experiments. In each graph, the white bars represent the relative expression found in the microarray experiments, and the grey bars represent the relative expression determined by normalised qRT-PCR.</p

MIPS Functional Category assignments of <i>S. chinensis</i> genes differentially expressed during inflorescence tissue development relative to seedling leaf development.

<p>MIPS Functional Category assignments of <i>S. chinensis</i> genes differentially expressed during inflorescence tissue development relative to seedling leaf development.</p

Subset of transcription factors determined to be up- or down-regulated in inflorescence tissues, relative to their transcript abundance levels in developing seedling leaves.

<p>Subset of transcription factors determined to be up- or down-regulated in inflorescence tissues, relative to their transcript abundance levels in developing seedling leaves.</p

<i>In-situ</i> hybridization analysis of EH662329 (<i>ScAP3-B</i>) and EG530711 (<i>ScPI-B</i>) in longitudinal sections of developing <i>S. chinensis</i> inflorescences.

<p>(A and B) <i>In-situ</i> hybridization with EH662329 and EG530711sense probe as negative controls, respectively. (C, E, G, I, K and L) <i>In-situ</i> hybridization using EH662329 anti-sense probe. (D, F, H, J, M, N) <i>In-situ</i> hybridization using EG530711 anti-sense probe. (C, D, K), (E, F, M), (G, H, N), and (I, J, L) represent four progressive stages in inflorescence development. sb, subtending bracts; st, stamens; c, carpels. Scale bars  = 500 µm.</p