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Four new polyhydroxylated steroidal saponins, parisverticillatosides A-D (1–4), together with four known spirostanol saponins (5–8) were isolated from the roots of Paris verticillata. Their structures were elucidated on the basis of extensive spectroscopic analysis and chemical evidences. The discovery of the new compounds 1–4 extended the diversity and complexity of this spirostanol saponin family. The saponins 5 and 6 exhibited cytotoxicities against two human glioma cell lines. [ABSTRACT FROM AUTHOR]

The chemical constituent investigation on the root bark of Ailanthus altissima leads to the isolation of a new β-carboline alkaloid, 14(S),15-dihydroxy-6-methoxy-β-carboline (1), along with nine known alkaloids. The structure of new compound was elucidated on basis of extensive spectroscopic analysis, especially two-dimensional (2D) NMR techniques and the absolute configuration of C-14 was determined by ECD calculation. The neuroprotective effect of the isolated compounds on PC12 cells against the serum deprivation injury was evaluated by MTT method. As a result, compound 7 revealed protective effect on PC12 cells and the cell survival rate was significantly increased. [ABSTRACT FROM AUTHOR]

We theoretically and experimentally investigate the temperature responses of two liquid-filled polarization maintaining photonic crystal fibers (PM-PCFs). The guidance mechanism of liquid-filled PM-PCFs is a hybrid of the modified total internal reflection and photonic bandgap (PBG) principles. According to the wavelength shifting of photonic band edges, a sensitivity of -10.033 nm/°C from 38 °C to 45 °C was achieved in the glycerol-filled PM-PCF, whereas an ultrahigh sensitivity up to -76.197 nm/°C from 59 °C to 63 °C was obtained in the toluene-filled PM-PCF. High temperature sensitivities stem from the high transmission window located in the first PBG. The thermal tunable filled PCFs with PBG effect properties will offer great potential for temperature sensing, as well as tunable bandpass filters.

Broadband supercontinuum (SC) spanning more than an octave was obtained in tapered seven-core photonic crystal fibers (PCFs) upon pumping with a 150-fs mode-locked fiber laser. The appearance of the second zero dispersion wavelength in the tapered section of the PCF limited the solitons' self-frequency shift. The simulations and experiments suggested that the unique group velocity in the tapered section could change the relative velocity of different spectral components, which resulted in some compression of the pulse in the time domain. It can be found that the spectral defects between the solitons were leveled up, and the visible region was enhanced remarkably, which was beneficial to control the SC generation. In addition, the interference fringes in the far field indicated the good spatial coherence of the output SC of the seven-core PCF.

Infectious spleen and kidney necrosis virus (ISKNV) is the type species of the Megalocytivirus genus of the Iridoviridae family. It causes a serious and potentially pandemic disease in wild and cultured fishes. ISKNV infection induces evident apoptosis in mandarin fish (Siniperca chuatsi) and zebrafish (Danio renio). However, the mechanism is still unknown. After a genome-wide bioinformatics analysis of ISKNV-encoded proteins, the ISKNV open reading frame 111L (ORF111L) shows a high similarity to the tumour necrosis factor receptor-associated factor (TRAF) encoded by fish, mice and mammals, which is essential for apoptotic signal transduction. Moreover, ORF111L was verified to directly interact with the zebrafish TNF receptor type 1 associated death domain protein (TRADD). A recombinant plasmid containing the DNA sequence of ORF111L was constructed and microinjected into zebrafish embryos at the 1-2 cell stage to investigate its biological function in vivo. ORF111L overexpression in the embryos resulted in increased apoptosis. ORF111L-induced apoptosis was clearly associated with significant caspase 8 upregulation and activation. The knockdown of zebrafish caspase 8 expression effectively blocked the apoptosis induced by ORF111L overexpression. Significantly, ORF111L overexpression resulted in much stronger effect on caspase 8 and caspase 3 upregulation compared to zebrafish TRAF2. This is the first report of a viral protein similar to TRAF that interacts with TRADD and induces caspase 8-mediated apoptosis, which may provide novel insights into the pathogenesis of ISKNV infection.

The chemical constituent investigation on the starfish Culcita novaeguineae resulted in the isolation of two new polyhydroxylated steroidal glycosides and two known ones. The new compounds were identified as (25S)-3-O-(2-O-methyl-β-D-xylopyranosyl)-26-O-(β-D-xylopyranosyl)-cholest-4-ene-3β,6β,7α,8,15α,16β,26-heptaol (1) and (25S)-3-O-(2-O-methyl-β-D-xylopyranosyl)-26-O-(β-D-xylopyranosyl)-cholest-4,24(28)-diene-3β,6β,7α,8,15α,16β,26-heptaol (2) and the known compounds were determined as linckosides I and H (3-4). The structures of the isolated compounds were elucidated on the basis of extensive spectroscopic studies and chemical evidence. In addition, the cytotoxicity of the two new compounds against human glioblastoma cell lines U87, U251 and SHG44 was evaluated by MTT method. [ABSTRACT FROM AUTHOR]

Many glioma patients develop resistance to temozolomide (TMZ) treatment, resulting in reduced efficacy and survival rates. TMZ‐resistant cell lines SHG44R and U87R, which highly express O6‐methylguanine DNA methyltransferase (MGMT) and P‐gp, were established. CN‐3, a new asterosaponin, showed cytotoxic effects on TMZ‐resistant cells in a dose‐ and time‐dependent manner via reactive oxygen species (ROS)‐mediated apoptosis and autophagy. Transmission electron microscopy and monodansylcadaverine (MDC) staining showed turgidity of the mitochondria and autophagosomes in CN‐3‐treated SHG44R and U87R cells. The autophagy inhibitor 3‐methyladenine was used to confirm the important role of autophagy in CN‐3 cytotoxicity in TMZ‐resistant cells. The ROS scavenger N‐acetyl‐ l‐cysteine (NAC) attenuated the levels of ROS induced by CN‐3 and, therefore, rescued the CN‐3 cytotoxic effect on the viability of SHG44R and U87R cells by Cell Counting Kit‐8 assays and JuLI‐Stage videos. MDC staining also confirmed that NAC rescued an autophagosome increase in CN‐3‐treated SHG44R and U87R cells. Western blotting revealed that CN‐3 increased Bax, cleaved‐caspase 3, cytochrome C, PARP‐1, LC3‐Ⅱ, and Beclin1, and decreased P‐AKT, Bcl‐2, and p62. Further rescue experiments revealed that CN‐3 induced apoptosis and autophagy through ROS‐mediated cytochrome C, cleaved‐caspase 3, Bcl‐2, P‐AKT, PARP‐1, and LC3‐Ⅱ. In addition, CN‐3 promoted SHG44R and U87R cells sensitive to TMZ by reducing the expression of P‐gp, MGMT, and nuclear factor kappa B p65, and it had a synergistic cytotoxic effect with TMZ. Moreover, CN‐3 disrupted the natural cycle arrest and inhibited the migration of SHG44R and U87R cells by promoting cyclin E1 and D1, and by decreasing P21, P27, N‐cadherin, β‐catenin, transforming growth factor beta 1, and Smad2. [ABSTRACT FROM AUTHOR]

The phytochemical investigation on the rhizomes of Paris yunnanensis Franch. resulted in the discovery and characterisation of six compounds, including two new saponins named parisyunnanosides M-N ( 1 - 2 ), and four known ones ( 3 - 6 ). The structures of isolated compounds were determined by spectroscopic data analysis and chemical methods. Compound 2 is a pregnane-type saponin with a special α , β -unsaturated carboxylic acid moiety at C-17, which is first discovered in genus Paris . The anti-inflammatory activity of the isolated compounds was assessed in vitro . The results demonstrated that compounds 3 and 4 could significantly inhibit the production of NO which was induced by LPS in RAW 264.7 cells with IC 50 values of 0.67 ± 0.17 μM and 0.85 ± 0.12 μM, respectively.