Anti-inflammatory lindenane sesquiterpenoid dimers from the roots of Chloranthus holostegius var. trichoneurus.

Two new lindenane-type sesquiterpenoid dimers, chlotrichenes C and D (1 and 2) together with five known lindenane-type sesquiterpenoid dimers (3-7) were isolated from the roots of Chloranthus holostegius var. trichoneurus, a famous natural medicine named as "Sikuaiwa" for subduing swellings and relieving pain. The structures including absolute configuration were elucidated by their 1D and 2D NMR, HRESIMS, and ECD data. Compounds 1 and 2 were classical [4 + 2] lindenane-type sesquiterpenoid dimers that differed from known analogs in oxidation profile, side chain profile, and double bond position. The new isolates and compound 3 exhibited significant inhibitory activity on IL-1ß production (IC50: 1-15 µM) in LPS-induced THP-1 cells and other compounds exhibited inhibitory activity on NO production in LPS-induced RAW 264.7 cells (IC50: 24-33 µM).

Isolation and biomimetic synthesis of phenylpropionyl phenylethylamines from Chloranthus henryi.

In this study, ten phenylpropionyl phenylethylamines, including five previously undescribed ones (1a/b, 2a/b, and 3), five known analogues (4-8), and two established phenylpropanoids precursors (9, 10) were isolated from the aerial parts of Chloranthus henryi Hemsl. Their structures, including absolute configurations, were determined by high-resolution mass spectrometry, enantio-separation, electronic circular dichroism calculation, and single crystal diffraction. Compounds 1a and 1b were the first examples of natural hetero-[2 + 2] cycloaddition products between phenylpropionyl phenylethylamine and phenylpropene. The plausible hetero-[2 + 2] biosynthesis pathway was confirmed by a photocatalytic biomimetic synthesis in eight steps, which also led to the production of three other potential natural homo-[2 + 2] adducts (1'a/b, 2', and 3'). Bioactivity screening indicated that these adducts bear medium inhibitory activity on nitric oxide generation, with IC50 values of 6-35 µM in RAW 264.7 macrophages.

Pseudonocardia humida sp. nov., an Actinomycete Isolated from Mangrove Soil Showing Distinct Distribution Pattern of Biosynthetic Gene Clusters.

A novel actinomycete strain, designated S2-4T, was isolated from a mangrove soil sample, and a polyphasic approach was employed to determine its taxonomic position. Phylogenetic analysis based on 16S rRNA gene indicated that strain S2-4T formed a unique clade next to that harboring Pseudonocardia dioxanivorans CB1190T, which shared the highest sequence similarity (98.20%) with the new isolate. Phylogenetic analysis based on core genes of genomic sequences displayed a different scenario, exhibiting closer phylogenetic relationship of strain S2-4T with several species with 16S rRNA gene sequence similarities ranging from 96.95 to 98.06%, which was confirmed by the phylogenetic tree reconstructed based on genomic sequences. Further, substantial differences between the genotypic properties of strain S2-4T and its closest neighbors, including digital DNA-DNA hybridization, average nucleotide identity, and distribution patterns of biosynthetic gene clusters (BGC), indicated the taxonomic position of strain S2-4T as a novel species of the genus Pseudonocardia. Accordingly, strain S2-4T was observed to show a different distribution pattern of a predicted BGC encoding ectoine by comparative genomic analysis, which could be strongly linked to its unique habitat distinct from where its close neighbors were isolated. The major cellular fatty acids were iso-C15:0, C21:0, and iso-C16:0. The predominant menaquinone was MK-8(H4). The polar lipids were composed of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidyl-N-monomethylethanolamine, phosphatidylcholine, phosphatidylinositol, phosphatidylinositol mannosides, and two unidentified glycolipids. Here, we propose a novel species of the genus Pseudonocardia: Pseudonocardia humida sp. nov. with the type strain S2-4T (= JCM 34291T = CGMCC 4.7706T).