Anticancer Activity of Two Novel Hydroxylated Biphenyl Compounds toward Malignant Melanoma Cells

Melanoma, the deadliest form of skin cancer, is still one of the most difficult cancers to treat despite recent advances in targeted and immune therapies. About 50% of advanced melanoma do not benefit of such therapies, and novel treatments are requested. Curcumin and its analogs have shown good anticancer properties and are being considered for use in combination with or sequence to recent therapies to improve patient outcomes. Our group previously published the synthesis and anticancer activity characterization of a novel curcumin-related compound against melanoma and neuroblastoma cells (D6). Here, two hydroxylated biphenyl compounds—namely, compounds 11 and 12—were selected among a small collection of previously screened C2-symmetric hydroxylated biphenyls structurally related to D6 and curcumin, showing the best antitumor potentiality against melanoma cells (IC₅₀ values of 1.7 ± 0.5 μM for 11 and 2.0 ± 0.7 μM for 12) and no toxicity of normal fibroblasts up to 32 µM. Their antiproliferative activity was deeply characterized on five melanoma cell lines by performing dose-response and clonal growth inhibition assays, which revealed long-lasting and irreversible effects for both compounds. Apoptosis induction was ascertained by the annexin V and TUNEL assays, whereas Western blotting showed caspase activation and PARP cleavage. A cell cycle analysis, following cell treatments with either compound 11 or 12, highlighted an arrest in the G2/M transition. Taking all this evidence together, 11 and 12 were shown to be good candidates as lead compounds to develop new anticancer drugs against malignant melanoma.     

Photoreflectance study of GaAs and GaAs/GaAlAs single quantum wells grown on (001) Si substrates

The optical features associated with biaxially strained bulk GaAs and three GaAs/GaAlAs quantum wells (QWs), with widths of 52 Å, 120 Å and 200 Å, grown on (001) Si have been studied using photoreflectance at 300 K and 77 K. The ordering and/or separation of the light- and heavy-hole quantum transitions in the QWs can be tuned by altering the width of the well.     

The Pseudomonas syringae pv. tomato HrpW protein has domains similar to harpins and pectate lyases and can elicit the plant hypersensitive response and bind to pectate

The host-specific plant pathogen Pseudomonas syringae elicits the hypersensitive response (HR) in nonhost plants and secretes the HrpZ harpin in culture via the Hrp (type III) secretion system. Previous genetic evidence suggested the existence of another harpin gene in the P. syringae genome. hrpW was found in a region adjacent to the hrp cluster in P. syringae pv. tomato DC3000. hrpW encodes a 42. 9-kDa protein with domains resembling harpins and pectate lyases (Pels), respectively. HrpW has key properties of harpins. It is heat stable and glycine rich, lacks cysteine, is secreted by the Hrp system, and is able to elicit the HR when infiltrated into tobacco leaf tissue. The harpin domain (amino acids 1 to 186) has six glycine-rich repeats of a repeated sequence found in HrpZ, and a purified HrpW harpin domain fragment possessed HR elicitor activity. In contrast, the HrpW Pel domain (amino acids 187 to 425) is similar to Pels from Nectria haematococca, Erwinia carotovora, Erwinia chrysanthemi, and Bacillus subtilis, and a purified Pel domain fragment did not elicit the HR. Neither this fragment nor the full-length HrpW showed Pel activity in A230 assays under a variety of reaction conditions, but the Pel fragment bound to calcium pectate, a major constituent of the plant cell wall. The DNA sequence of the P. syringae pv. syringae B728a hrpW was also determined. The Pel domains of the two predicted HrpW proteins were 85% identical, whereas the harpin domains were only 53% identical. Sequences hybridizing at high stringency with the P. syringae pv. tomato hrpW were found in other P. syringae pathovars, Pseudomonas viridiflava, Ralstonia (Pseudomonas) solanacearum, and Xanthomonas campestris. DeltahrpZ::nptII or hrpW::OmegaSpr P. syringae pv. tomato mutants were little reduced in HR elicitation activity in tobacco, whereas this activity was significantly reduced in a hrpZ hrpW double mutant. These features of hrpW and its product suggest that P. syringae produces multiple harpins and that the target of these proteins is in the plant cell wall.     

Pasteurization of Fruit Juices by Means of a Pulsed High Pressure Process

ABSTRACT: The use of pulsed high hydrostatic pressure was investigated as a possible approach to stabilize foodstuffs. The objective of this article was to investigate the effect of the main processing variables (pressure [150 to 300 MPa], temperature levels [25 to 50 °C], and pulse number [1 to 10]) on the sanitation of nonpasteurized clear Annurca apple juice as well as freshly-squeezed clear orange juice. The aim of the article was the optimization of the process parameters in step-wise pressure treatment (pressure holding time of each pulse: 60 s, compression rate: 10.5 MPa/s, decompression time: 2 to 5s). The shelf life of the samples, processed at optimized conditions, was evaluated in terms of microbiological stability and quality retention. According to our experimental results, the efficiency of pulsed high pressure processes depends on the combination of pulse holding time and number of pulses. The pulsed high pressure cycles have no additive or synergetic effect on microbial count. The efficacy of the single pulses decreases with the increase of the pulse number and pressure level. Therefore the first pulse cycle is more effective than the following ones. By coupling moderate heating to high pressure, the lethality of the process increases but thermal degradation of the products can be detected. The optimization of the process condition thus results in a compromise between the reduction of the pressure value, due to the synergetic temperature action, and the achievement of quality of the final production. The juices processed under optimal processing conditions show a minimum shelf life of 21 d at a storage temperature of 4 °C.     

Exfoliated/Intercalated Rubber/Organo‐Montmorillonite Nanocomposites: Preparation and Characterization

The preparation of new rubber based nanocomposites by using properly modified organophilic clays is described. A commercial organophilic montmorillonite containing a hydroxylated ammonium ion is reacted with LPBs. The reaction causes a decrease of the polarity of the clay and a great increase of the interlayer distance. The modified organoclays are successfully dispersed into rubber matrices (SBR or BR) by melt blending in an internal batch mixer. SAXS analyses and TEM micrographs revealed the formation of highly exfoliated nanocomposites containing intercalated stacks made of few lamellae.

     

Comparison of the compositional, microbiological, biochemical and volatile profile characteristics of three Italian PDO fermented sausages

Three Italian PDO fermented sausages, Varzi, Brianza and Piacentino, were compared for compositional, microbiological, biochemical and volatile profile characteristics. Mean values for the gross composition varied especially due to moisture, fat, total protein and nitrate concentration which reflected differences in the ingredients and some technological parameters. Cell numbers of the major microbial groups were almost similar among sausages. The major differences were found for Brochothrix thermosphacta, enterococci and moulds. Apart from their use as starters, Lactobacillus sakei and Lactobacillus curvatus were the dominant lactic acid bacteria and, as well as Staphylococcus xylosus, dominated the population of coagulase-negative staphylococci. Sausages differed for the hydrolysis of myofibrillar proteins and secondary proteolysis. Varzi, the sausage subjected to prolonged fermentation at 23–25 °C for 10 days before ripening, showed the highest degree of secondary proteolysis. Varzi and Brianza, the two fermented sausages manufactured by using microbial starters, showed the highest concentration and similar profiles of free amino acids. The peptidase activities contained in the aqueous extracts agreed with the above findings. A total of 52 volatile components, mainly alcohols, aldehydes and terpenes, were identified by solid-phase micro-extraction coupled with gas chromatography–mass spectrometry analysis. The volatile profiles of the three Italian PDO fermented sausages differed in part and, except for terpenes, the highest levels of the other chemical classes were found in Varzi and Brianza sausages. The composition of free fatty acids of the three Italian PDO sausages was rather similar. Monounsaturated fatty acids (MUFA) were found at the highest relative percentage followed by saturated (SFA) and polyunsaturated (PUFA) fatty acids. Oleic, palmitic, linoleic and stearic were the main free fatty acids found in all fermented sausages.     

Shelf-life extension of highbush blueberry using 1-methylcyclopropene stored under air and controlled atmosphere

The potential of 1-methylcyclopropene for controlling ripening in ‘Lateblue’ blueberry fruit was explored. After harvest, blueberry fruits were exposed to 1-MCP (0.3 and 0.6 μl l⁻¹). After treatment, samples were stored in air at 0 °C for 35 days and in a controlled atmosphere (3 kPa O₂ + 11 kPa CO₂) for 60 days. Quality parameters were monitored (weight loss, total soluble solids content, titratable acidity, firmness, anthocyanin content, phenolic content, total antioxidant capacity). Blueberries treated with 1-MCP showed a reduced weight loss during storage and a lower total soluble solid content compared to untreated fruit. High titratable acidity values were observed after controlled atmosphere storage, but no significant effect of 1-MCP on this parameter was observed. 1-MCP had no significant effects on anthocyanins, phenolics or antioxidant activities.