Fire retardancy and CO/CO2 emission of intumescent coatings on thin plywood panel with waterborne vinyl acetate-acrylic resin

Using intumescent coatings on wood-based materials is an effective method for fire safety. Previous studies have demonstrated that the formulation of components strongly influences the performance of coatings. This study investigated the effect of intumescent formulation of vinyl acetate-acrylic coating on flame retardancy of plywood. The fire retardancy of materials was assessed by both heat release and CO and CO₂ emissions. The CO and CO₂ emissions have not been used frequently to rank materials; the highly toxic CO and CO₂ may cause most fire fatalities. The fire retardancy of coatings on plywood was assessed by a cone calorimeter. Total heat release and time to peak heat release rate were the two primary parameters. The data show that low contents of binder resin (BR) and foam producing substance (FPS) decreased total heat release and lengthened time to peak heat release rate. Additionally, low BR and FPS content can form an ideal char layer. The ideal char layer significantly decreased the CO and CO₂ emission. The mechanism to achieve better fire performance was verified by thermogravimetrical analysis exhibiting lower weight loss. Moreover, evaluated by ³¹P NMR, the low BR and FPS content can extend the survival duration of phosphor-carbonaceous chars. The results provide information for designing vinyl acetate-acrylic emulsion coating.     

Antioxidant Activity and Characterization of Phenolic Compounds from Bacaba ( Oenocarpus bacaba Mart.) Fruit by HPLC-DAD-MS(n)

The phytochemicals in fruits have been shown to be major bioactive compounds with regard to health benefits. Bacaba ( Oenocarpus bacaba Mart.) is a native palm fruit from the Brazilian savannah and Amazon rainforest that plays an important role in the diet of rural communities and is also a source of income for poor people. This paper reports the characterization and analyses of phenolics from bacaba fruit extract. The total phenolic content of bacaba fruit amounted to 1759.27 ± 1.01 mg GAE/100 g, the flavonoid content was 1134.32 ± 0.03 mg CTE/100 g, and the anthocyanin content was 34.69 ± 0.00 mg cyn-3-glc/100 g. The antioxidant activity was evaluated through different assays [ORAC, FRAP, DPPH, TEAC, and cellular antioxidant assay (CAA) assays] and revealed a significant antioxidant capacity for bacaba in comparison to the data available in the literature. The assignment of the phenolic compounds using HPLC-DAD-MS(n) was based on the evaluation of their UV-vis absorption maxima (λ(max)) and mass spectral analyses, and 14 compounds were tentatively identified. The results suggest that bacaba fruits are a promising source of phenolics.     

Inducible nitric oxide synthase and cyclooxygenase-2 participate in anti-inflammatory activity of imperatorin from Glehnia littoralis

In this study, we have investigated the anti-inflammatory effects of imperatorin, a compound isolated from the roots of Glehnia littoralis, using a lipopolysaccharide (LPS)-stimulated mouse macrophage (RAW264.7) in vitro and a carrageenan (Carr)-induced mouse paw edema model in vivo. When RAW264.7 macrophages were treated with imperatorin together with LPS, a significant concentration-dependent inhibition of NO production was detected. Western blotting revealed that imperatorin blocked the protein expression of iNOS and cyclooxygenase-2 (COX-2) in LPS-stimulated RAW264.7 macrophages significantly. In the anti-inflammatory test, imperatorin decreased the paw edema at 4 and 5 h after Carr administration and increased the activities of catalase, superoxide dismutase, and glutathione peroxidase in paw edema. We also demonstrated that imperatorin significantly attenuated the malondialdehyde level in the edema paw at the fifth hour after Carr injection. Imperatorin decreased the NO and tumor necrosis factor and prostaglandin E2 levels on serum at 5 h after Carr injection. Western blotting revealed that imperatorin decreased Carr-induced iNOS and COX-2 expressions at 5 h in edema paw. An intraperitoneal injection treatment with imperatorin also diminished neutrophil infiltration into sites of inflammation as did indomethacin. The results suggested that imperatorin had anti-inflammatory effects in LPS-stimulated RAW 264.7 cells and Carr-injected mice, respectively. In addition, inhibition of elevated iNOS and COX-2 protein expression as well as neutrophil infiltration of Carr-injected paws may be involved in the beneficial effects of imperatorin.     

Cytotoxic sesterterpenoids from a sponge Hippospongia sp

One new pentacyclic sesterterpene, hippospongide A (1), and one new scalarane sesterterpenoid, hippospongide B (2), along with six previously reported known scalarane-type sesterterpenes (3-8), were isolated from a sponge Hippospongia sp. The structures of these compounds were elucidated on the basis of their spectroscopic data and comparison of the NMR data with those of known analogues. These metabolites are the first pentacyclic sesterterpene and scalarane-type sesterterpenes to be reported from this genus. Compounds 3-5 exhibited significant cytotoxicity against DLD-1, HCT-116, T-47D and K562 cancer cell lines.     

Vine cuttings as possible initial inoculum sources of Ralstonia solanacearum race 1 biovar 4 on vegetable sweet potato in fields

Ralstonia solanacearum, which consists of five races/biovars, is considered a “species-complex” and is an important phytopathogen that causes wilt disease in more than 200 plant species. R. solanacearum race 1 biovar 4 (R1bv4) has caused yield losses of 30–80 % in the vegetable sweet potato (VSP) in the last decade in Taiwan. To identify the source of the initial inoculum of R1bv4 in VSP fields, soil and cuttings from these fields were examined from 2009 to 2010. The results of the investigation indicated that the population of R1bv4 was generally distributed throughout the natural soil of VSP fields at a density ranging from 1.3?×?10² to 9.5?×?10⁵ cfu/g soil; however, the incidence of bacterial wilt was not significantly associated with the density of the R1bv4 population in soils (R²?=?0.084). In contrast, densities of R1bv4 ranging from 2.3?×?10³ to 5.9?×?10⁵ cfu/g tissue were detected in the vine tissue of asymptomatic plants in the fields. Additional experiments demonstrated that R1bv4-free VSP cuttings without visible symptoms planted in infested soils in the greenhouse setting could carry approximately 3.1?×?10⁵ R1bv4 cfu/g tissue, which suggests the existence of a latent period for R1bv4 in VSP plants. The results of a BIO-PCR analysis showed that R1bv4 was detected in 2.0 to 98.0 % of the VSP cuttings used for propagation in fields; in addition, the percentage of VSP cuttings carrying R1bv4 and the incidence of bacterial wilt in fields were positively correlated (R²?=?0.909). The inoculation experiments conducted in greenhouses and in fields showed that the cutting inoculum (CI) contributed more to the incidence of bacterial wilt in VSP plants than the soil inoculum (SI). In the field experiments conducted in 2010, an incidence of disease of 27.1 to 38.5 % was detected in healthy field cuttings 8 months after transplantation; in contrast, the incidence of disease in field cuttings carrying R1bv4 was 49.0 to 68.8 %. The incidence of disease was significantly lower in healthy cuttings than in cuttings carrying R1bv4 (p?=?0.05).     

Antioxidant and heme oxygenase-1 (HO-1)-induced effects of selected Taiwanese plants

Recent studies have shown biological effects of heme oxygenase-1 (HO-1) induction and antioxidation in cardiovascular disorders. The ethanol extracts of leaves of 12 selected indigenous Taiwanese plants were investigated for their antioxidant activities, evaluated using assays of 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and superoxide radicals scavenging and reducing power activities as well as the induction of heme oxygenase-1 (HO-1). Acer albopurpurascens, Cinnamomum kanehirai, Diospyros discolor, Excoecaria kawakamii, Koelreuteria henryi, and Syzygium formosanum showed better DPPH-scavenging activities than the other plants. IC(50) values ranged from 1.7 to 8.7 microg/mL. Excepting Millettia pulchra var. microphylla and Pittosporum moluccanum, the extracts displayed hydroxyl-scavenging activities (IC(50) of 0.16-0.67 microg/mL). A. albopurpurascens, D. discolor, K. henryi, and S. formosanum also showed good superoxide anion radical scavenging activities and IC(50) values ranged from 12.9 to 28.5 microg/mL. D. discolor, K. henryi, and S. formosanum showed potent reducing power and M. pulchra var. microphylla and S. formosanum exhibited potent HO-1 induced activity. These active plant extracts also contained abundant phenolic constituents. The present results provide candidates to isolate the active constituents and develop natural antioxidants.     

Bioactive Steroids from the Formosan Soft Coral Umbellulifera petasites

Three new steroids, petasitosterones A and B (1 and 2) and a spirosteroid petasitosterone C (3), along with eight known steroids (4–11), were isolated from a Formosan marine soft coral Umbellulifera petasites. The structures of these compounds were elucidated by extensive spectroscopic analysis and comparison of spectroscopic data with those reported. Compound 3 is a marine steroid with a rarely found A/B spiro[4,5]decane ring system. Compounds 1–3 and 5 displayed inhibitory activity against the proliferation of a limited panel of cancer cell lines, whereas 2 and 5 exhibited significant anti-inflammatory activity to inhibit nitric oxide (NO) production. The inhibitory activities for superoxide anion generation and elastase release of compounds 1–11 were also examined to evaluate the anti-inflammatory potential, and 2–4 were shown to exhibit significant activities.