Isolation of undescribed cladosporols and spirobisnaphthalenes from a plant pathogen Cladosporium cladosporioides F-10-2-A.

Two undescribed cladosporol derivatives, cladosporols J-K (1-2), and three previously unreported spirobisnaphthalenes, urnucratins D-F (3-5), as well as eleven known cladosporols (6-16), were characterized from Cladosporium cladosporioides (Cladosporiaceae), a common plant pathogen isolated from the skin of Chinese toad. Cladosporols J-K (1-2) with a single double bond have been rarely reported, while urnucratins D-F (3-5) featured an unusual benzoquinone bisnaphthospiroether skeleton, contributing to an expanding category of undiscovered natural products. Their structures and absolute configurations were determined using extensive spectroscopic methods, including NMR, HRESIMS analyses, X-ray single crystal diffraction, as well as through experimental ECD analyses. Biological assays revealed that compounds 1 and 2 exhibited inhibitory activity against A549 cells, with IC50 values of 30.11 ± 3.29 and 34.32 ± 2.66 µM, respectively.

Structure-Guided Discovery of Diverse Cytotoxic Dimeric Xanthones/Chromanones from Penicillium chrysogenum C-7-2-1 and Their Interconversion Properties.

Xanthone-chromanone homo- or heterodimers are regarded as a novel class of topoisomerase (Topo) inhibitors; however, limited information about these compounds is currently available. Here, 14 new (1-14) and 6 known tetrahydroxanthone chromanone homo- and heterodimers (15-20) are reported as isolated from Penicillium chrysogenum C-7-2-1. Their structures and absolute configurations were unambiguously demonstrated by a combination of spectroscopic data, single-crystal X-ray diffraction, modified Mosher's method, and electronic circular dichroism analyses. Plausible biosynthetic pathways are proposed. For the first time, it was discovered that tetrahydroxanthones can convert to chromanones in water, whereas chromone dimerization does not show this property. Among them, compounds 5, 7, 8, and 16 exhibited significant cytotoxicity against H23 cell line with IC50 values of 6.9, 6.4, 3.9, and 2.6 µM, respectively.

Time-dependent response of A549 cells upon exposure to cadmium.

Cadmium is considered one of the most harmful carcinogenic heavy metals in the human body. Although many scientists have performed research on cadmium toxicity mechanism, the toxicokinetic process of cadmium toxicity remains unclear. In the present study, the kinetic response of proteome in/and A549 cells to exposure of exogenous cadmium was profiled. A549 cells were treated with cadmium sulfate (CdSO4 ) for different periods and expressions of proteins in cells were detected by two-dimensional gel electrophoresis. The kinetic expressions of proteins related to cadmium toxicity were further investigated by reverse transcription-polymerase chain reaction and western blotting. Intracellular cadmium accumulation and content fluctuation of several essential metals were observed after 0-24 hours of exposure by inductively coupled plasma mass spectrometry. Fifty-four protein spots showed significantly differential responses to CdSO4 exposure at both 4.5 and 24 hours. From these proteins, four expression patterns were concluded. Their expressions always exhibited a maximum abundance ratio after CdSO4 exposure for 24 hours. The expression of metallothionein-1 and ZIP-8, concentration of total protein, and contents of cadmium, zinc, copper, cobalt and manganese in cells also showed regular change. In synthesis, the replacement of the essential metals, the inhibition of the expression of metal storing protein and the activation of metal efflux system are involved in cadmium toxicity.

Controllable Preparation of CuFeMnO4 Nanospheres as a Novel Multifunctional Affinity Probe for Efficient Adsorption and Selective Enrichment of Low-Abundance Peptides and Phosphopeptides.

A facile solvothermal method for the synthesis of multifunctional magnetic CuFeMnO4 nanospheres affinity probe (NSAP) with controllable morphology and size was developed for the first time. The CuFeMnO4 nanospheres combine the brilliant features of Cu2+, Fe3+, and Mn2+ ions, so their multifunction performances are embodied by strong coordination to carboxyl and amine groups of peptides (Cu2+ and Fe3+), special affinity to phosphate groups of phosphopeptides (Fe3+ and Mn2+), and high magnetic responsiveness in a magnetic field. Their potential as an affinity probe was evaluated for highly effective enrichment, rapid magnetic separation of low-abundance peptides (neutral condition), and effective selective capture of phosphopeptides (acid condition) from various complex biosamples. Notably, CuFeMnO4 NSAP was explored for highly selective capture and isolation of phosphopeptides from A549 cells after exposure to ZnO nanoparticles for different times. Consequently, we put forward a new nanospinel ferrite-based protocol here to analyze and identify the phosphoproteins/phosphopeptides involved in cellular signaling pathways in response to exogenous stimulation.

The Kinetic Response of the Proteome in A549 Cells Exposed to ZnSO4 Stress.

Zinc, an essential trace element, is involved in many important physiological processes. Cell responses to zinc stress show time-dependent effects besides concentration-dependence and tissue-specificity. Herein, we investigated the time-dependent differential expression of the proteome in A549 cells after administered with ZnSO4 for both 9 and 24 h using 2DE. 123 differentially expressed protein spots were detected, most of which were up-regulated by Zn2+ treatment. Interestingly, 49 proteins exhibited significant differential expression repeatedly during these two treatment periods, and moreover showed a conserved change with different ratios and four time-dependent expression patterns. Pattern 1 (up-regulated with rapid initial induction and subsequent repression) and pattern 4 (down-regulated with steady repression) were the predominant expression patterns. The abundances of the proteins in patterns 1 and 4 after 24 h of zinc treatment are always lower than that after 9 h, indicating that exogenous zinc reduced the expression of proteins in cells after 24 h or longer. Importantly, these findings could also reflect the central challenge in detecting zinc homeostasis proteins by 2DE or other high throughput analytical methods resulting from slight variation in protein expression after certain durations of exogenous zinc treatment and/or low inherent protein content in cells. These time-dependent proteome expression patterns were further validated by measuring dynamic changes in protein content in cells and in expression of two proteins using the Bradford method and western blotting, respectively. The time-dependent changes in total zinc and free Zn2+ ion contents in cells were measured using ICP-MS and confocal microscopy, respectively. The kinetic process of zinc homeostasis regulated by muffling was further revealed. In addition, we identified 50 differentially expressed proteins which are predominantly involved in metabolic process, cellular process or developmental process, and function as binding, catalytic activity or structural molecule activity. This study further elucidates our understanding of dynamic nature of the cellular response to zinc stress and the mechanism of zinc homeostasis.

[Feasibility of erlotinib after gefitinib failure in patients with advanced pulmonary adenocarcinoma previously responding to gefitinib].

OBJECTIVE: To evaluate the efficacy and progression-free survival of erlotinib after progression of disease to gefitinib in patients with advanced pulmonary adenocarcinoma who previously obtained a disease control with gefitinib. METHOD: In this retrospective study, 12 patients with advanced or metastatic pulmonary adenocarcinoma,who were previously obtained a partial response or a stable disease with gefitinib,were treated with erlotinib after gefitinib failure. Erlotinib efficiency, progression-free survival and overall survival were analyzed. RESULTS: Nice (75%)achieved stable disease and three (25%) achieved progression disease with erlotinib treatment after gefitinib failure. No complete response or partial response was observed. The disease control rate was 75%. The median progression-free survival and overall survival of erlotinib were 180 days and 831 days. CONCLUSION: Erlotinib seems to be an optional treatment after gefitinib failure for advanced pulmonary adenocarcinoma patients,who previously responded to gefitinib.