19 research outputs found
Secondary metabolites isolated from <i>Penicillium christenseniae</i> SD.84 and their antimicrobial resistance effects
A pair of new quinolone alkaloid enantiomers, (Ra)-(-)-viridicatol (1) and (Sa)-(+)-viridicatol (4), and seven known compounds, namely, 2, 3 and 5–9, were isolated from Penicillium christenseniae SD.84. The structures of 1 and 4 were determined using NMR and HRESIMS data. Theoretical calculations through CD and ECD confirmed 1 and 4 as a pair of enantiomers. The MIC values of 4 against Staphylococcus aureus and methicillin-resistant S. aureus were 12.4 and 24.7 μM, respectively, compound 1 had no inhibitory activity. Antimicrobial assays of 2, 3, and 5–7 showed a moderate activity against S. aureus and methicillin-resistant S. aureus. This study demonstrated the remarkable potential of Penicillium sp. to produce new drug-resistant leading compounds, thereby advancing the mining for new sources of antimicrobial agents.</p
The Plackett-Burman design for screening variables for C<sub>15</sub>-surfactin production.
<p>R<sup>2</sup> = 96.25%, R<sup>2</sup> (adj)  = 86.25%.</p>*<p>Coef: coefficient.</p
ANOVA of regression model.
<p>Determination of coefficient R<sup>2</sup> = 0.9611; adjusted determination coefficient Adj R<sup>2</sup> = 0.9262.</p>1<p>DF, Degree of freedom;</p>2<p>SS, sum of squares;</p>3<p>MS, mean square.</p
Caesanines A–D, New Cassane Diterpenes with Unprecedented N Bridge from <i>Caesalpinia sappan</i>
Serial antibacterial furanoditerpenes caesanines A–D (<b>1</b>–<b>4</b>), possessing a cassane-type diterpenoid skeleton with an unusual N bridge between C-19/C-20, were identified from a Chinese herb <i>Caesalpinia sappan</i> Linn. In addition, caesanine D (<b>4</b>) showed the first class of dicassane diterpenoid ethers. Their structures were determined by different spectroscopic methods and ECD calculation. Caesanines A and B exhibited strong activities against MRSA suggesting a promising entry point for the development of anti-infective drugs
Regression coefficients and their significance for response surface model.
a<p><i>X<sub>1</sub>, X<sub>2</sub> and X<sub>3</sub></i> represent Sucrose, NH<sub>4</sub>NO<sub>3</sub> and NaH<sub>2</sub>PO<sub>4</sub>•2H<sub>2</sub>O, respectively.</p
Effects of nitrogen source on the production of C<sub>15</sub>-surfactin from <i>B. amyloliquefaciens</i> MB199 with sucrose as the carbon source.
<p>Effects of nitrogen source on the production of C<sub>15</sub>-surfactin from <i>B. amyloliquefaciens</i> MB199 with sucrose as the carbon source.</p
Effects of carbon source on the production of C<sub>15</sub>-surfactin from <i>B. amyloliquefaciens</i> MB199.
<p>Effects of carbon source on the production of C<sub>15</sub>-surfactin from <i>B. amyloliquefaciens</i> MB199.</p
Neighbour-joining phylogenetic tree of <i>B. amyloliquefaciens</i> MB199 constructed by Mega 4.0.
<p>Numbers at nodes indicate levels of bootstrap support (%) based on a neighbour-joining analysis of 1000 resampled datasets; only values >50% are given. NCBI accession numbers are given in parentheses. Bar, 0.005 nucleotide substitutions per site.</p
Response surface plot for C<sub>15</sub>-surfactin production by <i>B. amyloliquefaciens</i> MB199.
<p>Response surface plot for C<sub>15</sub>-surfactin production by <i>B. amyloliquefaciens</i> MB199.</p