3-Phenyl-5-methyl-2H,5H-furan-2-ones: tuning antifungal activity by varying substituents on the phenyl ring

A series of racemic 3-phenyl-5-methyl-2H,5H-furan-2-ones related to a natural product, (-)incrustoporine, was synthesized, and their antifungal activity evaluated. The key structural feature, furanone ring, was closed via H2SO4-mediated cyclization of 2-phenylpent-4-enoic acids. The compounds displayed antifungal activity, especially against filamentous fungi. Expressed as the minimum inhibition concentration (MIC) in micromol/L, the activity of the most promising derivative against Absidia corymbifera matched that of ketoconazole (31.25 micromol/L). In terms of microg/mL, the substance was more active (7.6 microg/mL) than this standard antifungal drug (16.6 microg/mL).     

Specific interaction of TFII-I with an upstream element on the HIV-1 LTR regulates induction of latent provirus

RBF-2 is a factor comprised of a USF1/2 heterodimer, whose association with a highly conserved upstream element (RBEIII) on the HIV-1 LTR requires a co-factor TFII-I. We have identified specific nucleotides, immediately 3′ of RBEIII that are required for stable association of TFII-I with this region of the LTR. Mutations that inhibit interaction of TFII-I with DNA also prevent stimulation of USF binding to RBEIII, and render the integrated LTR unresponsive to T cell signaling. These results demonstrate an essential role of TFII-I bound at an upstream LTR element for viral replication.     

Investigation of the mechanism of action of 3-(4-bromophenyl)-5-acyloxymethyl-2,5-dihydrofuran-2-one against Candida albicans by flow cytometry

The mechanism of action of the antifungal agent 3-(4-bromophenyl)-5-acyloxymethyl-2,5-dihydrofuran-2-one against Candida albicans was investigated by flow cytometry, using propidium iodide, DiBAC4(3), and FUN-1 as the fluorescent dyes. A related but less active agent, together with amphotericin B and fluconazole, was tested in parallel for comparison of the results. The incrustoporine derivative was found to have a potent fungicidal activity on C. albicans, resulting in damage of cell membrane.     

Validation of EST-derived STS markers localized on Qfhs.ndsu-3BS for Fusarium head blight resistance in wheat using a 'Wangshuibai' derived population

A few EST-derived STS markers localized on Qfhs.ndsu-3BS, a major QTL for resistance to Fusarium head blight (FHB) in wheat, have been previously identified in the 'Sumai 3'/'Stoa' population. In this study, we used a 'Wangshuibai' (resistant)/'Seri82' (susceptible) derived population, linkage group, QTL, and quantitative gene expression analysis to assess the genetic background dependence and stability of the EST-derived STS markers for use in marker aided selection to improve FHB resistance in wheat. Based on our results, a QTL in the map interval of Xsts3B-138_1-Xgwm493 on chromosome 3BS was detected for FHB resistance, which accounted for up to 16% of the phenotypic variation. BLASTN analysis indicated that Xsts3B-138_1 sequence had significant similarity with the resistance gene analogue. Real-time quantitative PCR showed that the relative expression of Xsts3B-1381 in 'Wangshuibai' at 96 h after inoculation was 2.6 times higher than 'Seri82'. Our results underlined that EST-derived STS3B-138 markers could be predominantly used in marker aided selection to improve FHB resistance in wheat.     

Phenylthiocarbamide produces conditioned taste aversions in mice

Previous work has demonstrated that SWR/J (SW) mice avoid phenylthiocarbamide (PTC) to a greater degree than C3HeB/FeJ mice in 48 h, two-bottle preference tests given in ascending series. The authors hypothesized, based also on previous work, that SW mice might form a conditioned taste aversion over time due to the toxic properties of PTC. We directly tested this hypothesis by attempting to condition a taste aversion to sucrose by injections of PTC. In experiment 1, PTC was nearly as effective as a strong dose of LiCl in reducing sucrose drinking. In experiment 2, the sucrose aversions were parametrically modified by both sucrose concentration and PTC dose, a hallmark of conditioned taste aversion. We conclude that PTC can cause a conditioned taste aversion and discuss the importance of considering toxic effects of aversive tastants when analyzing behavioral strain differences.     

Effect of salt stress on some physio-biochemical traits and antioxidative enzymes of two Brassica species under callus culture

The changes in lipid peroxidation, H₂O₂, proline, protein, involvement of different antioxidant systems (catalase, guaiacol peroxidase, ascorbate peroxidase) and callus-related traits were investigated under salt stress in the callus of two different ploidy levels of Brassica including B. juncea and B. oleracea. The calluses of B. juncea genotypes were less sensitive to NaCl stress in comparison with those of B. oleracea while increasing the concentrations of NaCl from 0 to 200 mM. Tetraploid genotype (B. juncea cr3356) showed a significant increase in the contents of protein and proline, and guaiacol peroxidase activity and catalase enzymes at higher salinity levels. In addition, a significant decrease occurred in the amount of H₂O₂ and malondialdehyde along with increasing the salinity intensity. Diploid cultivar (B. oleracea bra 2828) had the lowest enzymatic activities and the highest content of H₂O₂ and malondialdehyde along with an increase in the salinity level. Therefore, this genotype was identified as the most sensitive cultivar under the salinity stress. The salinity resistance difference between diploid and amphidiploid species could be attributed to the differences in the ploidy level of these species. This result underlines the fact that the tetraploid genome of B. oleracea could be considered as a suitable candidate for production under salinity conditions through maintaining higher activities of antioxidant enzymes.