Porous covalent organic framework nanofibrous membrane for excellent enrichment and ultra-high sensitivity detection of trace organochlorine pesticides in water.

Developing adsorbents with high performance and long service life for effective extracting the trace organochlorine pesticides (OCPs) from real water is attracting numerous attentions. Herein, a self-standing covalent organic framework (COF-TpPa) membrane with fiber morphology was successfully synthesized by using electrospun nanofiber membranes as template and employed as solid-phase microextraction (SPME) coating for ultra-high sensitivity extraction and analysis of trace OCPs in water. The as-synthesized COF-TpPa membrane exhibited a high specific surface area (800.83 m2 g-1), stable nanofibrous structure, and excellent chemical and thermal stability. Based on the COF-TpPa membrane, a new SPME analytical method in conjunction with gas chromatography-mass spectrometry (GC-MS) was established. This proposed method possessed favorable linearity in concentration of 0.05-2000 ng L-1, high sensitivity with enrichment factors ranging from 2175 to 5846, low limits of detection (0.001-0.150 ng L-1), satisfactory precision (RSD < 10 %), and excellent repeatability (>150 cycles), which was better than most of the reported works. Additionally, the density functional theory (DFT) calculations and XPS results demonstrated that the outstanding enrichment performance of the COF-TpPa membrane was owing to synergistic effect of π-π stacking effects, high specific surface area and hydrogen bonding. This work will expect to extend the applications of COF membrane to captures trace organic pollutants in complex environmental water, as well as offer a multiscale interpretation for the design of effective adsorbents.

Parishin from Gastrodia elata Extends the Lifespan of Yeast via Regulation of Sir2/Uth1/TOR Signaling Pathway.

Parishin is a phenolic glucoside isolated from Gastrodia elata, which is an important traditional Chinese medicine; this glucoside significantly extended the replicative lifespan of K6001 yeast at 3, 10, and 30 µM. To clarify its mechanism of action, assessment of oxidative stress resistance, superoxide dismutase (SOD) activity, malondialdehyde (MDA), and reactive oxygen species (ROS) assays, replicative lifespans of sod1, sod2, uth1, and skn7 yeast mutants, and real-time quantitative PCR (RT-PCR) analysis were conducted. The significant increase of cell survival rate in oxidative stress condition was observed in parishin-treated groups. Silent information regulator 2 (Sir2) gene expression and SOD activity were significantly increased after treating parishin in normal condition. Meanwhile, the levels of ROS and MDA in yeast were significantly decreased. The replicative lifespans of sod1, sod2, uth1, and skn7 mutants of K6001 yeast were not affected by parishin. We also found that parishin could decrease the gene expression of TORC1, ribosomal protein S26A (RPS26A), and ribosomal protein L9A (RPL9A) in the target of rapamycin (TOR) signaling pathway. Gene expression levels of RPS26A and RPL9A in uth1, as well as in uth1, sir2 double mutants, were significantly lower than those of the control group. Besides, TORC1 gene expression in uth1 mutant of K6001 yeast was inhibited significantly. These results suggested that parishin exhibited antiaging effects via regulation of Sir2/Uth1/TOR signaling pathway.

Anti-aging effects of phloridzin, an apple polyphenol, on yeast via the SOD and Sir2 genes.

The anti-aging effects of phloridzin on the yeast Saccharomyces cerevisiae were investigated by employing a replicative lifespan assay of the K6001 yeast strain. After administrating phloridzin at doses of 3, 10, and 30 µM, the lifespan of the yeast was significantly prolonged in comparison with the untreated group (p<0.01, p<0.001). To determine the mechanism of action, anti-oxidative experiments and ROS assay were performed. Phloridzin improved the viability of the yeast dose-dependently under oxidative stress by 7.5 mM H(2)O(2), and a low dose of phloridzin inhibited ROS of the yeast. Further, SOD1, SOD2, and Sir2 gene expression was examined by reverse transcription-polymerase chain reaction (RT-PCR), and was found to be significantly increased. Finally, superoxide dismutase (SOD) and SIRT1 activity assays showed that phloridzin notably increased the activity of SOD and SIRT1. These results suggest that SOD and Sir2 have important roles in phloridzin-regulated lifespan extension of yeast, and potentially anti-aging effects for mammalian cells via SIRT1.

Ganodermasides C and D, two new anti-aging ergosterols from spores of the medicinal mushroom Ganoderma lucidum.

Two new anti-aging compounds, ganodermasides C and D, were isolated and their structures elucidated. They are novel ergosterols possessing a 4,6,8(14),22-tetraene-3-one unit with unique hydroxylation at C-9. Both of them significantly extended the replicative lifespan of the K6001 yeast strain. Ganodermasides C and D regulated the expression of the gene for UTH1 to prolong the replicative lifespan of yeast.

Ganodermasides A and B, two novel anti-aging ergosterols from spores of a medicinal mushroom Ganoderma lucidum on yeast via UTH1 gene.

Two novel ergosterol derivatives, ganodermasides A and B, hydroxylated at C-15 were isolated from the methanol extract of spores of a medicinal mushroom, Ganoderma lucidum, showed to extend the replicative life span of Saccharomyces cerevisiae, a yeast of K6001 strain. The stereostructures of ganodermasides A and B were determined based on the spectroscopic analysis and comparison of spectroscopic data. These new sterols have a 4, 6, 8(14), 22-tetraene-3-one unit with a unique hydroxylation at C-15. The anti-aging activity of these compounds on yeast is comparable to a well-known substance, resveratrol. Based on results of the investigation of the mechanism of biological activity, ganodermasides A and B regulated UTH1 expression in order to extend the replicative life span of yeast.