Paenibacillus yonginensis sp. nov., a potential plant growth promoting bacterium isolated from humus soil of Yongin forest

Strain DCY84^T, a Gram-stain positive, rod-shaped, aerobic, spore-forming bacterium, motile by means of peritrichous flagella, was isolated from humus soil from Yongin forest in Gyeonggi province, South Korea. Strain DCY84^T shared the highest sequence similarity with Paenibacillus barengoltzii KACC 15270^T (96.86 %), followed by Paenibacillus timonensis KACC 11491^T (96.49 %) and Paenibacillus phoenicis NBRC 106274^T (95.77 %). Strain DCY84^T was found to able to grow best in TSA at temperature 30 °C, at pH 8 and at 0.5 % NaCl. MK-7 menaquinone was identified as the isoprenoid quinone. The major polar lipids were identified as phosphatidylethanolamine, an unidentified aminophospholipid, two unidentified aminolipids and an unidentified polar lipid. The peptidoglycan was found to contain the amino acids meso-diaminopimelic acid, alanine and d-glutamic acid. The major fatty acids of strain DCY84^T were identified as branched chain anteiso-C_15:0, saturated C_16:0 and branched chain anteiso-C_17:0. The cell wall sugars of strain DCY84^T were found to comprise of ribose, galactose and xylose. The major polyamine was identified as spermidine. The DNA G+C content was determined to be 62.6 mol%. After 6 days of incubation, strain DCY84^T produced 52.96 ± 1.85 and 72.83 ± 2.86 µg/ml l-indole-3-acetic acid, using media without l-tryptophan and supplemented with l-tryptophan, respectively. Strain DCY84^T was also found to be able to solubilize phosphate and produce siderophores. On the basis of the phenotypic characteristics, genotypic analysis and chemotaxonomic characteristics, strain DCY84^T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus yonginensis sp. nov. is proposed. The type strain is DCY84^T (=KCTC 33428^T = JCM 19885^T).     

Structural requirement(s) of N-phenylthioureas and benzaldehyde thiosemicarbazones as inhibitors of melanogenesis in melanoma B 16 cells

In order to define the structural requirements of phenylthiourea (PTU), a series of thiourea and thiosemicarbazone analogs were prepared and evaluated as inhibitors of melanogenesis in melanoma B16 cells. The most potent analog was 2-(4-tert-butylbenzylidene)hydrazinecarbothioamide (1u) with an IC₅₀ value of 2.7 μM in inhibition of melanogenesis. The structure for potent inhibitory activity of these derivatives are required with the direct connection of π-planar structure to thiourea without steric hinderance in PTU derivatives and the hydrophobic substituent at para position in case of semicarbazones.     

Lignan derivatives from Selaginella tamariscina and their nitric oxide inhibitory effects in LPS-stimulated RAW 264.7 cells

The chemical characterization of Selaginella tamariscina leaves resulted in the isolation of five lignanoside derivatives (1–4 and 6) and one neolignan (5). These compounds include three new lignanosides, tamariscinosides D–F (1–3), and one liriodendrin (4) that were isolated for the first time from this plant, together with two known compounds, (2R,3S)-dihydro-2-(3,5-dimethoxy-4-hydroxyphenyl)-7-methoxy-5-acetyl-benzofuran (5) and moellenoside B (6). The chemical structures of these isolated compounds were determined using 1D and 2D NMR, MS, and CD spectroscopic data, and the results were compared to data previously reported in the literatures. These compounds were also evaluated in terms of their inhibition of NO production in lipopolysaccharide (LPS)-stimulated activity in the macrophage cell line RAW 264.7. Among them, compounds 1, 2, 5, and 6 exhibited a significant inhibition with IC₅₀ values ranging from 32.3 to 55.8 μM.     

Cytotoxic triterpene diglycosides from the sea cucumber Stichopus horrens

Using various chromatographic separation techniques, eight triterpene diglycosides (1–8), including four new compounds namely stichorrenosides A–D (1–4), were isolated from a methanol extract of the Vietnamese sea cucumber S. horrens. Their structures were elucidated based on spectroscopic analyses, including HR ESI MS, 1D and 2D NMR. Their in vitro cytotoxic activity against five human cancer cell lines, Hep-G2 (hepatoma cancer), KB (epidermoid carcinoma), LNCaP (prostate cancer), MCF7 (breast cancer), and SK-Mel2 (melanoma), was evaluated using SRB methods. Stichorrenoside D (4), stichoposide A (5), and 3β-O-[β-d-xylopyranosyl-(1→2)-β-d-xylopyranosyl]-23S-acetoxyholost-7-ene (7) showed strong cytotoxicity on all five tested cancer cell lines, whereas significant effect was observed for stichorrenoside C (3) and stichoposide B (6).     

A rapid and simple method for identifying bacterial polar lipid components in wet biomass

There are marked differences between wet and freeze-dried cells with regard to the identification of polar lipid components. The determination of the polar lipid composition of freeze-dried cells is well established. However, several approaches to identifying polar lipid components in wet cells have met with limited success owing to the presence of non-polar compounds in the extracts, resulting in a lipid composition with a narrow scope. In this study, we surveyed the lipid profiles of the wet biomasses of three Gram-positive (Microbacterium lacticum, Rhodococcus koreensis, and Streptomyces longwoodensis) and two Gram-negative (Pseudomonas aeruginosa and Novosphingobium capsulatum) bacteria; the results were comparable in quality to those obtained using a standard freeze-dried approach. Moreover, our improved method ensures simple lipid extraction. Overall, the results of the analysis showed minor lipid profile differences between the two approaches with regard to quantity, and lipid identification was consistent in both methods for all species.     

Quantitative Proteomics Employing Primary Amine Affinity Tags

A proteomics-based method using stable isotope labeling to assess the relative abundance of peptides or proteins is described. Bradykinin and carbonic anhydrase were labeled with sulfosuccinimidyl-2-(biotinamido) ethyl-1,3-dithiopropionate, a membrane impermeant reagent that is reactive with primary amines. Specificity of the label to primary amines was demonstrated using tandem mass spectrometry. Also, relative quantitation was achieved by secondary labeling with natural isotopic abundance and stable isotope-labeled methyl iodide. We believe this to be an effective stable isotope-labeling method for quantitative proteomics.