Rhytidenones A–F, Spirobisnaphthalenes from <i>Rhytidhysteron</i> sp. AS21B, an Endophytic Fungus

Rhytidenone A (<b>1</b>), a unique spirobisnaphthalene with a 1,7-dioxaspiro­[4,4]­nonan-2-one motif, and five new spirobisnaphthalenes, rhytidenones B–F (<b>2</b>–<b>6</b>), were isolated from the extract of a cultured fungal endophyte, <i>Rhytidhysteron</i> sp. AS21B. Their structures were elucidated mainly by analysis of NMR spectroscopic data. The structure and configuration of <b>1</b> were further confirmed by single-crystal X-ray diffraction analysis. Compounds <b>3</b> and <b>4</b> exhibited significant inhibitory activity against nitric oxide production from activated macrophages with IC₅₀ values of 0.31 and 3.60 μM, respectively

Rhytidenones A–F, Spirobisnaphthalenes from <i>Rhytidhysteron</i> sp. AS21B, an Endophytic Fungus

Rhytidenone A (<b>1</b>), a unique spirobisnaphthalene with a 1,7-dioxaspiro­[4,4]­nonan-2-one motif, and five new spirobisnaphthalenes, rhytidenones B–F (<b>2</b>–<b>6</b>), were isolated from the extract of a cultured fungal endophyte, <i>Rhytidhysteron</i> sp. AS21B. Their structures were elucidated mainly by analysis of NMR spectroscopic data. The structure and configuration of <b>1</b> were further confirmed by single-crystal X-ray diffraction analysis. Compounds <b>3</b> and <b>4</b> exhibited significant inhibitory activity against nitric oxide production from activated macrophages with IC₅₀ values of 0.31 and 3.60 μM, respectively

Weakly Anti-inflammatory Limonoids from the Seeds of <i>Xylocarpus rumphii</i>

Seven new limonoids, namely, xylorumphiins E–J (<b>1</b>−<b>2</b> and <b>4</b>−<b>7</b>) and 2-hydroxyxylorumphiin F (<b>3</b>), along with three known derivatives (<b>8</b>–<b>10</b>), were isolated from the seeds of <i>Xylocarpus rumphii</i>. 2-Hydroxyxylorumphiin F (<b>3</b>) and xylorumphiin I (<b>6</b>) displayed moderate inhibitory activity against nitric oxide production from lipopolysaccharide-activated macrophages with IC₅₀ values of 24.5 and 31.3 μM, respectively

Ultrastrong, Transparent Polytruxillamides Derived from Microbial Photodimers

Ultrastrong and transparent bioplastics are generated from fermented microbial monomers. An exotic aromatic amino acid, 4-aminocinnamic acid, was prepared from a biomass using recombinant bacteria, and quantitatively photodimerized, and diacid and diamino monomers that were both characterized by a rigid α-truxillate structure were generated. These two monomers were polycondensed to create the polyamides with a phenylene­cyclobutane repeating backbone such as poly­{(4,4′-diyl-α-truxillic acid dimethyl ester) 4,4′-diacetamido-α-truxillamide} which was processed into amorphous fibers and plastic films having high transparency. In spite of noncrystalline structure, mechanical strength of the fiber is 407 MPa at maximum higher than those of other transparent plastics and borosilicate glasses, presumably due to the tentative molecular spring function of the phenylene­cyclobutanyl backbone