Dammarane-type saponins from Gynostemma pentaphyllum

Dammarane-type saponins, gypenosides VN1–VN7 (1–7), were isolated from the total saponin extract of Gynostemma pentaphyllum aerial parts, with their structures elucidated on the basis of spectroscopic and chemical methods. These compounds showed moderate cytotoxic activity against four human cancer cell lines, A549 (lung), HT-29 (colon), MCF-7 (breast), and SK-OV-3 (ovary), with IC₅₀ values ranging from 19.6 ± 1.1 to 43.1 ± 1.0 μM. Regarding the HL-60 (acute promyelocytic leukemia) cell line, compounds 1, 5, and 6 showed weakly active with IC₅₀ values of 62.8 ± 1.9, 72.6 ± 3.6, and 82.4 ± 3.2 nM, respectively, while 2, 3, 4, and 7 were less active with IC₅₀ values >100 μM.     

28-nor-oleanane-type triterpene saponins from Camellia japonica and their inhibitory activity on LPS-induced NO production in macrophage RAW264.7 cells

Four new 28-nor-oleanane-type triterpene oligoglycosides, camellenodiol 3-O-β-D-galactopyranosyl(1→2)[β-D-xylopyranosyl(1→2)-β-D-galactopyranosyl(1→3)]-β-D-glucuronopyranoside (2), camellenodiol 3-O-4'-O-acetyl-β-D-galactopyranosyl(1→2)[β-D-xylopyranosyl(1→2)-β-D-galactopyranosyl(1→3)]-β-D-glucuronopyranoside (4), camellenodiol 3-O-(β-D-galactopyranosyl(1→2)[β-D-xylopyranosyl(1→2)-β-D-galactopyranosyl(1→3)]-6'-methoxy-β-D- glucuronopyranoside (5), and maragenin II 3-O-(β-D-galactopyranosyl(1→2)[β-D-xylopyranosyl(1→2)-β-D-galactopyranosyl(1→3)]-6'-methoxy-β-D-glucuronopyranoside (6), along with two known compounds, (1 and 3), were isolated from the stem bark of Camellia japonica. Their chemical structures were established mainly by 2D NMR techniques and mass spectrometry. The isolated compounds showed inhibitory effects on NO production in RAW264.7 macrophages.     

Inhibitors of osteoclastogenesis from Lawsonia inermis leaves

Ten phenolic compounds (1–10) were isolated from a methanol extract of Lawsonia inermis leaves including two new ones, lawsoniasides A (1) and B (2). Their structures were elucidated by spectroscopic methods (NMR and FTICRMS) in combination with acid hydrolysis and GC analyses. Compounds 4 and 5 showed a significant inhibition on receptor activator for nuclear factor-κB ligand-induced osteoclast formation in murine bone-marrow macrophages.     

MIDAS: software for analysis and visualisation of interallelic disequilibrium between multiallelic markers

Background  

Various software tools are available for the display of pairwise linkage disequilibrium across multiple single nucleotide polymorphisms. The HapMap project also presents these graphics within their website. However, these approaches are limited in their use of data from multiallelic markers and provide limited information in a graphical form.     

Nitrogen Use Efficiency of Rice Cultivars (Oryza sativa L.) Under Salt Stress and Low Nitrogen Conditions

Improving nitrogen use efficiency (NUE) under salt stress has become crucial for rice as it is increasingly facing two major environmental constraints: excessive nitrogen fertilization and soil salinization. However, the interaction between salinity and N levels is very complex and has not yet been considered from the perspective of reduced nitrogen input. We conducted a hydroponic experiment at the early tillering stage on the Yoshida solution to evaluate the impact of rising NaCl and decreasing N application on NUE of four rice cultivars cultivated under three NaCl (0, 56, and 113 mM) and four N (2.86, 1.43, 0.72, and 0.36 mM) concentrations. After 4 weeks, physiological NUE (pNUE), absorption NUE (aNUE), agronomical NUE (agNUE), N transport efficiency (NTE), and physiological traits were evaluated. Significant interactions between N and NaCl-applied concentrations were found in all measured parameters. In all cultivars, increasing the NaCl-applied concentration markedly decreased aNUE and agNUE. For each NaCl treatment, lowering the N applied sharply increased aNUE and agNUE, and this effect was stronger when the NaCl applied was higher. The effect of N lowering on pNUE depended on the NaCl treatment: it enhanced pNUE in the absence of NaCl but had no influence under the highest NaCl-applied concentration. Cultivars largely differed in response to NaCl. The aNUE—but not pNUE—differed between salt-tolerant and salt-sensitive cultivars: aNUE markedly decreased with NaCl concentration in the most salt-sensitive cultivar, whereas it was the highest at the intermediate NaCl concentration in the most salt-tolerant cultivar, especially under low N levels. This finding suggests that under salt conditions, the use of salt-tolerant rice genotypes combined with reducing N level application is necessary to improve NUE. The study of NUE in rice should be focused on the improvement of aNUE with a strong emphasis on the salt tolerance of cultivars.

     

Isogenic auxotrophic mutant strains in the <Emphasis Type="Italic">Aspergillus fumigatus</Emphasis> genome reference strain AF293

Aspergillus fumigatus is a ubiquitous fungus that is a frequent opportunistic pathogen in immunosuppressed patients. Because of its role as a pathogen, it is of considerable experimental interest. A set of auxotrophic isogenic strains in the A. fumigatus genome reference strain AF293 has been developed. Using molecular genetic methods, arginine and lysine auxotrophs were made by deletion of argB and lysB, respectively. Transformation of these auxotrophic strains with plasmids carrying argB or lysB, respectively, results in efficient integration at these loci. Finally, these strains are able to form stable diploids, which should further facilitate analysis of gene functions in this fungus. Furthermore, the development of this isogenic set of auxotrophic strains in the AF293 background will enable investigators to study this important opportunistic human pathogen with greater facility.