n-Butanol

Project ID

1542

Category

IRIS

Added on

Dec. 14, 2010, 3:50 p.m.

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Journal Article

Abstract  Understanding of degradation mechanisms in polymer:fullerene bulk-heterojunctions on the microscopic level aimed at improving their intrinsic stability is crucial for the breakthrough of organic photovoltaics. These materials are vulnerable to exposure to light and/or oxygen, hence they involve electronic excitations. To unambiguously probe the excited states of various multiplicities and their reactions with oxygen, we applied combined magneto-optical methods based on multifrequency (9 and 275 GHz) electron paramagnetic resonance (EPR), photoluminescence (PL), and PL-detected magnetic resonance (PLDMR) to the conjugated polymer poly(3-hexylthiophene) (P3HT) and polymer:fullerene bulk heterojunctions (P3HT:PCBM; PCBM = [6,6]-phenyl-C(61)-butyric acid methyl ester). We identified two distinct photochemical reaction routes, one being fully reversible and related to the formation of polymer:oxygen charge transfer complexes, the other one, irreversible, being related to the formation of singlet oxygen under participation of bound triplet excitons on the polymer chain. With respect to the blends, we discuss the protective effect of the methanofullerenes on the conjugated polymer bypassing the triplet exciton generation.

Journal Article

Abstract  The effect of a nanoscale boron subphthalocyanine chloride (SubPc) interfacial layer on the performance of inverted polymer solar cells based on poly (3-hexyl thiophene) (P3HT) and [6,6]-phenyl-C(71)-butyric acid methyl ester (PC(71)BM) was studied. When a 1 nm SubPc layer was introduced between the active layer (P3HT:PC(71)BM) and MoO(x) in the device with ITO/ZnO/P3HT:PC(71)BM/SubPc/MoO(x)/Al configuration, the power conversion efficiency (PCE) was increased from 3.42 (without SubPc) to 3.59%. This improvement is mainly attributed to the enhanced open-circuit voltage from 0.62 to 0.64 V. When the Flory-Huggins interaction parameters were estimated from the solubility parameters through the contact angle measurement, it revealed that the interaction between SubPc and PC(71)BM is more attractive than that between SubPc and P3HT at the interface of P3HT:PC(71)BM/SubPc, through which charges are well transported from the active layer to the anode. This is supported by a decrease of the contact resistance from 5.49 (SubPc 0 nm) to 0.94 MΩ cm (SubPc 1 nm). The photoelectron spectra provide another evidence for the enhanced PCE, exhibiting that the 1 nm thick SubPc layer extracts more photoelectrons from the active layer than other thicknesses.

Journal Article

Abstract  AIM: This study evaluated the effect of 2-hydroxymethyl methacrylate (HEMA) and the type of solvent on the tensile bond strength of the following three self-etch adhesives: Adper easy one (HEMA-rich adhesive) which contained ethanol, G-Bond (HEMA-free adhesive) which contained acetone, and Xeno V (HEMA-free adhesive) which contained butanol as a solvent.

MATERIAL AND METHODS: Intact mandibular molars were mounted in self-cured resin and the occlusal surfaces were ground with # 600 SiC paper. Adhesives were applied on the prepared dentinal surfaces and the resin composite was condensed in the split brass mold (5 × 3 mm) placed over the adhesive surface. The specimens were stored in normal saline and placed in incubator at 37°C. After 24 hours, the specimens were tested in tensile mode at a crosshead speed of 1 mm/min. Statistical analysis was done using One way ANOVA and Tukey's HSD test.

RESULTS: The mean bond strengths of Adper easy one, G-Bond, and Xeno V were 12.41 MPa, 10.09 MPa, and 8.67 MPa, respectively.

CONCLUSIONS: Comparison of contemporary adhesives in this ex vivo study revealed that the ethanol-based HEMA-rich self-etch adhesive is better than HEMA-free self-etch adhesive that contained acetone and butanol as the solvents, when compared in terms of bond strength.

Journal Article

Abstract  In the present study, the root nodules of Premna herbacea Roxb. (PH) was investigated for its in vitro cytotoxicity and in vivo antitumor activity. Two extracts, aqueous and alcoholic; two fractions of alcoholic extract, ethyl acetate and butanol fractions were screened for their in vitro cytotoxicity by brine shrimp lethality (BSL) assay, trypan blue exclusion assay and MTT assay. Alcoholic extract and its ethyl acetate fraction were found to be the most effective in BSL assay, trypan blue exclusion assay. In vivo antitumor activity was screened in the Ehrlich ascites carcinoma (EAC) model and the Dalton lymphoma ascites (DLA) model. The extracts and the fractions were tested at two dosages (250 and 500mg/kg) by intraperitoneally (i.p.) route on every alternate day upto 13th day. Cisplatin was used as positive control in both studies in single dose (day 1) 3.5mg/kg by i.p. route. In EAC model, ascites tumor was induced by inoculating 2.5 million of EAC cells i.p. alcoholic extract at 500mg/kg was the most effective in elevating MST, reduction in body weight in EAC induced tumor. Only the effective extract i.e., alcoholic extract were studied for hematological and antioxidant parameter. It showed a restoring effect on altered hematological parameters and a significant improvement in biochemical parameters at 250mg/kg dose of alcoholic extract. These results explain the toxicity of 500mg/kg might be high. In the Dalton lymphoma ascites (DLA) model, solid tumor was developed by i.m. injection of 1 million DLA cells. Both the extracts and the fractions possessed potent antitumor activity against solid tumor models by significantly reducing the solid tumor weight and volume.

Journal Article

Abstract  AIM AND BACKGROUND: Antibiotic resistance currently spans most of the known classes of natural and synthetic antibiotics; limiting our options for treatment of infections and demanding discovery of new classes of antibiotics. Much effort is being directed towards developing new antibiotics to overcome this problem. Success in getting novel chemical entities from microbial sources depends essentially on novelty of its habitat. The diversity of geographical location decides the type of micro-flora. In the past various terrestrial and aqueous microorganisms have provided several novel bioactive secondary metabolites of pharmaceutical importance. Hot-springs have not been as extensively exploited as other terrestrial resources. However, perseverance with such microbes augment the probability of getting novel bioactive compounds.

MATERIALS AND METHODS: Hot-springs soil samples were collected from Hot-springs in Maharashtra. Actinomycetes and other eubacteria were isolated from these soil samples by selective methods and purified. They were classified based on gram's nature and morphology. Six representative morphological strains were screened for their anti-infective potential by agar well diffusion method as reported by Nathan P. et al (1974). The bioactivity of the active microbes was confirmed.

RESULTS: Seventy three strains of bacteria encompassing eight actinomycetes, and 65 eubacteria were isolated and purified. Among the actives eubacteria PPVWK106001 showed broad spectrum antibacterial activity encompassing both gram positive and gram negative bacterial test models. The extract was active against resistant bacteria such as MRSA and VREs. Activity was very specific as there was no activity against fungi even at 100 fold concentration. The active principle was extractable in butanol.

CONCLUSIONS: The study showed that Hot-springs exhibit diverse bacteria and it serves as potential reservoirs for bacteria of antimicrobial importance with diverse facet of activities. Thus Hot-springs microbes have ability to address issue of resistant bugs.

Journal Article

Abstract  OBJECTIVE: To analyze the ultraviolet-screening of the n-butanol extracts of mangosteen pericarp and alpha-mangostin, compare the ultraviolet-screening effect of the extracts with rutin and ultramicro-titanium dioxide (TiO2).

METHODS: The samples (n-butanol extract from mangosteen pericarp, alpha-mangostin, rutin and TiO2) were scanned at different wavelength and Pan-wavelength by ultraviolet spectrophotometry.

RESULTS: The n-butanol extracts and alpha-mangostin had relatively satisfactory effects on ultraviolet-screening when the concentration was over 0.40 mg/ml and the effects on ultraviolet-screening was better than TiO2.

CONCLUSION: The n-butanol extracts and alpha-mangostin had a positive ultraviolet-screening activity which was better than TiO2.

Journal Article

Abstract  This review tries to find a scientific answer on the following two questions: (1) to what extent do we understand the specific role of colonic microbial metabolites, especially short-chain fatty acids (SCFA), in maintaining the health status and prevention of diseases of the colon and the host; (2) to what extent can we influence or even control the formation of colonic microbial metabolites which are beneficial for the health status. The review focuses on the following topics: energy source, intestinal motility, defence barrier, oxidative stress with special attention for antiinflammatory and anti-carcinogen functions, and satiety. Also the risk of overproduction of SCFA is discussed. Reviewing the literature as present today, it can be concluded that physiological levels of SCFA are vital for the health and well-being of the host and that the presence of carbohydrates (dietary fibre, prebiotics) is essential to favour the metabolic activity in the direction of carbohydrate fermentation. For optimal motor activity of the ileum and colon, to regulate the physiological intestinal mobility, steadily fermentable dietary fibres or prebiotics are crucial. The formation of SCFA, especially propionate and butyrate, up to high physiological levels in the colon, much likely also contributes to the defence mechanisms of the intestinal wall. No final answer can be given yet about the role of SCFA in anti-inflammation and anti-carcinogenicity, but recently published research shows possible mechanisms in this field. The intake of prebiotics or specific dietary fibres promotes the formation of SCFA within the physiological range, and more or less specifically increases the levels of propionate and butyrate. In this way, they provide benefit to the host, especially the natural regulation of the digestive system.

Journal Article

Abstract  Herein we report the generation of counterion radicals and their reactions in quaternary water-in-oil microemulsion. Hydrated electrons in the microemulsion CTAB/H(2)O/n-butanol/cyclohexane have a remarkably short half-life (∼1 μs) and lower yield as compared to that in the pure water system. Electrons are solvated in two regions: one is the water core and other the interface; however, the electrons in the water core have a shorter half-life than those in the interface. The decay of the solvated electrons in the interface is found to be water content dependent and it has been interpreted in terms of increased interfacial fluidity with the increase in water content of the microemulsion. Interestingly another species, dibromide radical anion (Br(2)(•-)) in CTAB and CPB microemulsions have been observed after the electron beam irradiation. Assuming that the extinction coefficient of the radicals is the same as that in the aqueous solution, the yields of the radicals per 100 eV are 0.29 and 0.48 for the Br(2)(•-) radical in CTAB and CPB containing microemulsions (W(0) = 40), respectively, under N(2)O saturated conditions. Further, we intended to study electron transfer reactions, which occur at and through the interface. The reaction of the Br(2)(•-) radical anion with ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] has been studied to generate the ABTS radical in the water core, and further, its reaction has been investigated with the water-insoluble molecule vitamin E (tocopherol) and water-soluble vitamin C (ascorbic acid). In the present study, we were able to show that, even for molecules which are completely insoluble in water, ABTS scavenging assay is possible by pulse radiolysis technique. Furthermore, these results show that it is possible to follow the reaction of the hydrated inorganic radical with solutes dissolved in the organic phase in a microemulsion without use of a phase transfer catalyst.

Journal Article

Abstract  BACKGROUND: Isobutanol can be a better biofuel than ethanol due to its higher energy density and lower hygroscopicity. Furthermore, the branched-chain structure of isobutanol gives a higher octane number than the isomeric n-butanol. Saccharomyces cerevisiae was chosen as the production host because of its relative tolerance to alcohols, robustness in industrial fermentations, and the possibility for future combination of isobutanol production with fermentation of lignocellulosic materials.

RESULTS: The yield of isobutanol was improved from 0.16 to 0.97 mg per g glucose by simultaneous overexpression of biosynthetic genes ILV2, ILV3, and ILV5 in valine metabolism in anaerobic fermentation of glucose in mineral medium in S. cerevisiae. Isobutanol yield was further improved by twofold by the additional overexpression of BAT2, encoding the cytoplasmic branched-chain amino-acid aminotransferase. Overexpression of ILV6, encoding the regulatory subunit of Ilv2, in the ILV2 ILV3 ILV5 overexpression strain decreased isobutanol production yield by threefold. In aerobic cultivations in shake flasks in mineral medium, the isobutanol yield of the ILV2 ILV3 ILV5 overexpression strain and the reference strain were 3.86 and 0.28 mg per g glucose, respectively. They increased to 4.12 and 2.4 mg per g glucose in yeast extract/peptone/dextrose (YPD) complex medium under aerobic conditions, respectively.

CONCLUSIONS: Overexpression of genes ILV2, ILV3, ILV5, and BAT2 in valine metabolism led to an increase in isobutanol production in S. cerevisiae. Additional overexpression of ILV6 in the ILV2 ILV3 ILV5 overexpression strain had a negative effect, presumably by increasing the sensitivity of Ilv2 to valine inhibition, thus weakening the positive impact of overexpression of ILV2, ILV3, and ILV5 on isobutanol production. Aerobic cultivations of the ILV2 ILV3 ILV5 overexpression strain and the reference strain showed that supplying amino acids in cultivation media gave a substantial improvement in isobutanol production for the reference strain, but not for the ILV2 ILV3 ILV5 overexpression strain. This result implies that other constraints besides the enzyme activities for the supply of 2-ketoisovalerate may become bottlenecks for isobutanol production after ILV2, ILV3, and ILV5 have been overexpressed, which most probably includes the valine inhibition to Ilv2.

Journal Article

Abstract  Inflammatory skin disorders, such as psoriasis and atopic dermatitis, are very common in the population; however, the treatments currently available are not well tolerated and are often ineffective. Averrhoa carambola L. (Oxalidaceae) is an Asian tree that has been used in traditional folk medicine in the treatment of several skin disorders. The present study evaluates the topical anti-inflammatory effects of the crude ethanolic extract of A. carambola leaves, its hexane, ethyl acetate, and butanol fractions and two isolated flavonoids on skin inflammation. Anti-inflammatory activity was measured using a croton oil-induced ear edema model of inflammation in mice. Topically applied ethanolic extract reduced edema in a dose-dependent manner, resulting in a maximum inhibition of 73 ± 3% and an ID(50) value of 0.05 (range: 0.02-0.13) mg/ear. Myeloperoxidase (MPO) activity was also inhibited by the extract, resulting in a maximum inhibition of 60 ± 6% (0.6 mg/ear). All of the fractions tested caused inhibition of edema formation and of MPO activity. Treatment with the ethyl acetate fraction was the most effective, resulting in inhibition levels of 75 ± 5 and 54 ± 8% for edema formation and MPO activity, respectively. However, treatment of mice with isolated compounds [apigenin-6-C-β-l-fucopyranoside and apigenin-6-C-(2″-O-α-l-rhamnopyranosyl)-β-l-fucopyranoside] did not yield successful results. Apigenin-6-C-(2″-O-α-l-rhamnopyranosyl)-β-l-fucopyranoside caused only a mild reduction in edema formation (28 ± 11%). Taken together, these preliminary results support the popular use of A. carambola as an anti-inflammatory agent and open up new possibilities for its use in skin disorders.

Journal Article

Abstract  In an organic photovoltaic device, a layer consisting of two organic compounds, one functioning as an electron acceptor and the other as an electron donor, is sandwiched between two electrodes. Sufficient concentration of the electron acceptor is required at the interface to the low work function electrode as well as sufficient concentration of the electron donor at the interface to the high work function electrode. Frequently used compounds are poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM). It is reported in the literature that blends of these materials show a gradient throughout the polymer layer within devices due to phase separation. The direction of the gradient is dependent on the surface energy of the substrates onto which the polymer solutions are spincoated. This is assumed to be detrimental in the usual device structure of photovoltaic devices. In this report the surface of the blend was studied with a combination of a depth profiling technique sensitive for elemental composition and two electron spectroscopy techniques differing in their surface sensitivity. After spin coating, a thin layer of PCBM with a thickness of approximately a single monolayer was found just below the blend surface. The implication for organic photovoltaic devices is discussed.

Journal Article

Abstract  Bulk heterojunction organic photovoltaic devices based on poly[N-9''-hepta-decanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole) (PCDTBT)/[6,6]-phenyl C(70) butyric acid methyl ester (PC(70)BM) can be successfully fabricated by a sequential solution deposition process. When the top layer is deposited from an appropriate cosolvent, the PC(70)BM penetrates a predeposited bottom layer of PCDTBT during the spin-casting process, resulting in an interdiffused structure with a layer-evolved bulk heterojunction (LE-BHJ) nanomorphology. The PCDTBT:PC(70)BM LE-BHJ solar cells prepared with an optimized cosolvent ratio have comparable power conversion efficiency to the conventional BHJ solar cells. The nanomorphology of the optimized PCDTBT:PC(70)BM LE-BHJ mixture was found to have better vertical connectivity than the conventional BHJ material.

Journal Article

Abstract  The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity of the fruits of Rubus chingii was studied in vitro. Ethanolic extract, ethyl acetate and n-butanol fractions from dried R. chingii fruits revealed strong DPPH free radical scavenging activity with IC(50) values of 17.9, 3.4 and 4.0 μg/mL, respectively. The ethyl acetate and n-butanol fractions were further purified by a combination of silica gel chromatography, Lobar RP-8 chromatography, and high-pressure liquid chromatography (HPLC). Nine compounds were isolated, where methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (2), vanillic acid (5), kaempferol (7), and tiliroside (9) showed stronger DPPH free radical scavenging activity than that of ascorbic acid (131.8 μM) with IC(50) values of 45.2, 34.9, 78.5, and 13.7 μM, respectively. In addition, rubusine (1) is a new compound discovered in the present study and methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (2), methyl dioxindole-3-acetate (3), and 2-oxo-1,2-dihydroquinoline-4-carboxylic acid (4) were isolated from the fruits for the first time.

Journal Article

Abstract  The genes of CS-2 lipase and its cognate foldase were cloned from Pseudomonas aeruginosa CS-2. A stop codon was not found in the lipase gene. The amino acid sequence deduced from the lipase gene from P. aeruginosa CS-2 showed 97.8%, 71.3%, and 71.2% identity with lipases from P. aeruginosa LST-03, P seudomonas mendocina ymp, and Pseudomonas stutzeri A1501, respectively. The co-expression of CS-2 lipase and its cognate foldase of P. aeruginosa CS-2 in E scherichia coli BL21 (DE3) resulted in the formation of a soluble lipase. The recombinant lipase and foldase were purified to homogeneity using nickel affinity chromatography and about 10.2-fold with 40.9% recovery was achieved for the purification of the recombinant lipase. The molecular masses of the lipase and the foldase were estimated to be 35.7 and 38.3 kDa in SDS-PAGE, respectively. The recombinant lipase showed stability in the presence of some organic solvents. The recombinant CS-2 lipase was immobilized and subsequently used for the synthesis of butyl acetate in heptane. The conversion of substrate decreased from 98.2% to 87.4% after 5 cycles in reuse of the immobilized lipase.

Journal Article

Abstract  Photolysis of metalated (Cu and Ni) and free base 2-diazo-3-oxochlorins within a frozen matrix (λ = 457.9 nm, toluene, 80 K) generates a single photointermediate with a hypsochromically shifted electronic absorption spectrum relative to the starting diazochlorins. The appearance of ketene (~2131 cm(-1)) and azete (~1670 cm(-1)) vibrations in infrared absorption and Raman spectra, respectively, identifies this intermediate as resulting from the Wolff rearrangement of the diazochlorins upon N(2) loss. Computational modeling of the vibrational spectra and TDDFT simulation of the electronic transitions of potential photointermediates corroborate this assignment. Isolation and analysis of photoproducts of these diazochlorins formed within n-butanol-doped frozen toluene matrices indicate near exclusive formation of azeteoporphyrins. In sharp contrast, room temperature laser photolysis of these materials yields a mixture of photoproducts deriving from the presence of both carbene and ketene intermediates. Computational modeling of the intramolecular reactivity of the proposed sp(2) carbene intermediate shows exclusive bond insertion to the adjacent phenyl group, and no evidence of Wolff rearrangement. Computational reaction profile analyses reveal that the barrierless Wolff rearrangement proceeds via an out-of-plane carbene electronic configuration that is generated directly during the loss of N(2). The formation of out-of-plane carbene, resulting in the exclusive formation of the observed ketene photointermediate at low temperatures, is consistent with orbital symmetry considerations and by the geometric constraints imposed by the frozen matrix. Combined, this leads to a model showing that azeteoporphyrin formation via the Wolff rearrangement is dependent upon the structural disposition of the adjacent framework, and the specific reaction intermediate formed is very sensitive to this feature.

Journal Article

Abstract  BACKGROUND: Phenolic constituents were the principle bioactivity compounds exist in Gynura divaricata, little phenolic compounds were reported from the plant previously.

MATERIALS AND METHODS: 60% ethanol extract from the leaves of Gynura divaricata were isolated and purified by column chromatography of Silica gel, ODS and Sephadex LH-20, the structures of the isolated compounds were identified by UV, 1H-NMR, 13C-NMR and MS spectroscopic techniques. Additionally, a high-performance liquid chromatography-diode array detector-electrospray ionization-mass (HPLC-DAD-ESI-MS) analytical method was developed to identify some minor constituents in the n-butanol fraction of the ethanol extract of Gynura divaricata.

RESULTS: Six flavonols and one Dicaffeoylquinic acid were isolated from the leaves of Gynura divaricata, and these compounds were identified as follows: quercetin (1), kaempferol (2), kaempferol-3-O-β-D-glucopyranoside (3), quercetin-3-O-rutinoside (4), kaempferol-3,7-di-O-β-D-glucopyranoside (5), kaempferol-3-O-rutinoside-7-O-β-D-glucopyranoside (6), and 3,5-dicaffeoylquinic acid (7). A total of 13 compounds, including 9 flavonol glycosides and 4 phenolic acids, were tentatively identified by comparing their retention time (RT), UV, and MS spectrum values with those that had been identified and the published data.

CONCLUSION: This was the first time to use the HPLC-DAD-ESI-MS method to identify the phytochemicals of the genera Gynura. Moreover, compounds (6) and (7) have been isolated for the first time from the genus Gynura.

Journal Article

Abstract  The present study investigated the enhanced radiosensitivity of U-251 cells induced by sodium butyrate (NaB) and its possible mechanisms. Increased radiosensitivity of U251 cells was examined by clonogenic cell survival assays. The expression of Ku70 mRNA and protein was detected by using RT-PCR and Western blotting respectively. γ-H2AX foci were measured at different time points after ionizing irradiation alone or combined with NaB treatment. The results showed that cell survival rate was significantly reduced, both D0 and Dq values were decreased (D0: 1.43 Gy vs. 1.76 Gy; Dq: 1.22 Gy vs. 2.05 Gy) after the combined treatment as compared with irradiation alone, and sensitivity enhancing ratio (SER) reached 1.23. The average number of γ-H2AX foci per cell receiving the combined treatment was significantly increased at different time points, and the expression levels of Ku70 mRNA and protein were suppressed by NaB in a dose-dependent manner. It was concluded that enhanced radiosensitivity induced by NaB involves an inhibited expression of Ku70 and an increase in γ-H2AX foci, which suggests decreased ability in DSB repair.

Journal Article

Abstract  Butyrate is a four-carbon short-chain fatty acid that improves colonic trophism. Although several studies have shown the benefits of butyrate enemas in ulcerative colitis (UC), studies using the oral route are rare in the literature. In the present study, we evaluated the effect of butyrate intake in the immune response associated to UC. For that, mice were fed control or butyrate (0.5% sodium butyrate) diets for 14 days. Acute UC was induced by dextran sulphate sodium (DSS, 2.5%), replacing drinking water. The results showed that, in UC animals, oral butyrate significantly improved trophism and reduced leukocyte (eosinophil and neutrophil) infiltration in the colon mucosa and improved the inflammatory profile (activated macrophage, B and T lymphocytes) in cecal lymph nodes. In the small intestine, although mucosa histology was similar among groups, DSS treatment reduced duodenal transforming growth factor-β, increased interleukin-10 concentrations and increased memory T lymphocytes and dendritic cells in Peyer's patches. Butyrate supplementation was able to revert these alterations. When cecal butyrate concentration was analyzed in cecal content, it was still higher in the healthy animals receiving butyrate than in the UC+butyrate and control groups. In conclusion, our results show that oral administration of sodium butyrate improves mucosa lesion and attenuates the inflammatory profile of intestinal mucosa, local draining lymph nodes and Peyer's patches of DSS-induced UC. Our results also highlight the potential use of butyrate supplements as adjuvant in UC treatment.

Journal Article

Abstract  In this work the phase behavior of [6,6]-phenyl C(61)-butyric acid methyl ester (PCBM) blends with different poly(phenylene vinylene) (PPV) samples is investigated by means of standard and modulated temperature differential scanning calorimetry (DSC and MTDSC) and rapid heat-cool calorimetry (RHC). The PPV conjugated polymers include poly(2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene) (MDMO-PPV), High T(g)-PPV which is a copolymer, and poly((2-methoxy-5-phenethoxy)-1,4-phenylene vinylene) (MPE-PPV). Comparisons of these PPV:PCBM blends with regioregular poly(3-hexyl thiophene) (P3HT):PCBM blends are made to see the different component miscibilities among different blends. The occurrence of liquid-liquid phase separation in the molten state of MDMO-PPV:PCBM and High T(g)-PPV:PCBM blends is indicated by the coexistence of double glass transitions for blends with a PCBM weight fraction of around 80 wt%. This is in contrast to the P3HT:PCBM blends where no phase separation is observed. Due to its high cooling rate (about 2000 K min(-1)), RHC proves to be a useful tool to investigate the phase separation in PPV:PCBM blends through the glass transition of these crystallizable blends. P3HT is found to have much higher thermal stability than the PPV samples.

Journal Article

Abstract  The nature of main in-plane skeleton Raman modes (C=C and C-C stretch) of poly(3-hexylthiophene) (P3HT) in pristine and its blend thin films with [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM) is studied by resonant and nonresonant Raman spectroscopy and Raman simulations. Under resonant conditions, the ordered phase of P3HT with respect to its disordered phase is identified by (a) a large shift in the C=C mode peak position to lower wavenumber (~21 cm(-1) shift), (b) a narrower fwhm of the C=C mode (~9 cm(-1) narrower), (c) a larger intensity of the C-C mode relative to the C=C mode (~56% larger), and (d) a very small Raman dispersion (~5 cm(-1)) of the C=C mode. The behavior of the C=C and C-C modes of the ordered and disordered phases of P3HT can be explained in terms of different molecular conformations. The C=C mode of P3HT in P3HT:PCBM blend films can be reproduced by simple superposition of the two peaks observed in different phases of P3HT (ordered and disordered). We quantify the molecular order of P3HT after blending with PCBM and the subsequent thermal annealing to be 42 ± 5% and 94 ± 5% in terms of the fraction of ordered P3HT phase, respectively. The increased molecular order of P3HT in blends upon annealing correlates well with enhanced device performance (J(SC), -4.79 to -8.72 mA/cm(2) and PCE, 1.07% to 3.39%). We demonstrate that Raman spectroscopy (particularly under resonant conditions) is a simple and powerful technique to study molecular order of conjugated polymers and their blend films.

Journal Article

Abstract  Abutilon indicum (L.) Sweet is an Asian phytomedicine traditionally used to treat several disorders, including diabetes mellitus. However, molecular mechanisms supporting the antidiabetic effect of A. indicum L. remain unknown. The aim of this study was to evaluate whether extract of A. indicum L. improves insulin sensitivity. First, we observed the antidiabetic activity of aqueous extract of the entire plant (leaves, twigs and roots) of A. indicum L. on postprandial plasma glucose in diabetic rats. The subsequent experiments revealed that butanol fractions of the extract bind to PPARγ and activate 3T3-L1 differentiation. To measure glucose uptake enhanced by insulin-like activity, we used rat diaphragm incubated with various concentrations of the crude extract and found that the extract enhances glucose consumption in the incubated solution. Our data also indicate that the crude extract and the fractions (water and butanol) did not affect the activity of kinases involved in Akt and GSK-3β pathways; however, the reporter assay showed that the crude extract could activate glucose transporter 1 (GLUT1) promoter activity. These results suggest that the extract from A. indicum L. may be beneficial for reducing insulin resistance through its potency in regulating adipocyte differentiation through PPARγ agonist activity, and increasing glucose utilization via GLUT1.

Journal Article

Abstract  A novel anaerobic, moderately thermophilic, NaCl-requiring fermentative bacterium, strain OS1T, was isolated from oil production water collected from Alaska, USA. Cells were Gram-negative, non-motile, non-spore-forming rods (1.7-2.7×0.4-0.5 µm). The G+C content of the genomic DNA of strain OS1T was 46.6 mol%. The optimum temperature, pH and NaCl concentration for growth of strain OS1T were 55 °C, pH 7 and 10 g l(-1), respectively. The bacterium fermented D-fructose, D-glucose, maltose, D-mannose, α-ketoglutarate, L-glutamate, malonate, pyruvate, L-tartrate, L-asparagine, Casamino acids, L-cysteine, L-histidine, L-leucine, L-phenylalanine, L-serine, L-threonine, L-valine, inositol, inulin, tryptone and yeast extract. When grown on D-glucose, 3.86 mol hydrogen and 1.4 mol acetate were produced per mol substrate. Thiosulfate, sulfur and L-cystine were reduced to sulfide, and crotonate was reduced to butyrate with glucose as the electron donor. 16S rRNA gene sequence analysis indicated that strain OS1T was related to Anaerobaculum thermoterrenum (99.7 % similarity to the type strain), a member of the phylum Synergistetes. DNA-DNA hybridization between strain OS1T and A. thermoterrenum DSM 13490T yielded 68 % relatedness. Unlike A. thermoterrenum, strain OS1T fermented malonate, maltose, tryptone, L-leucine and L-phenylalanine, but not citrate, fumarate, lactate, L-malate, glycerol, pectin or starch. The major cellular fatty acid of strain OS1T was iso-C15:0 (91 % of the total). Strain OS1T also contained iso-C13:0 3-OH (3 %), which was absent from A. thermoterrenum, and iso-C13:0 (2 %), which was absent from Anaerobaculum mobile. On the basis of these results, strain OS1T represents a novel species of the genus Anaerobaculum, for which the name Anaerobaculum hydrogeniformans sp. nov. is proposed. The type strain is OS1T (=DSM 22491T=ATCC BAA-1850T). An emended description of the genus Anaerobaculum is also given.

Journal Article

Abstract  The efficacy of decoction in extracting mycobactericidal compounds from Flourensia cernua (Hojasé) leaves and fractionation with solvents having ascending polarity was compared with that of (i) ethanol extraction by still maceration, extraction with a Soxhlet device, shake-assisted maceration, or ultrasound-assisted maceration, followed by fractionation with n-hexane, ethyl acetate, and n-butanol; (ii) sequential extraction with n-hexane, ethyl acetate, and n-butanol, by still maceration, using a Soxhlet device, shake-assisted maceration, or ultrasound-assisted maceration. The in vitro mycobactericidal activity of each preparation was measured against drug-sensitive (SMtb) and drug-resistant (RMtb) Mycobacterium tuberculosis strains. The results of which were expressed as absolute mycobactericidal activity (AMA). These data were normalized to the ΣAMA of the decoction fraction set. Although decoction was inactive, the anti-RMtb normalized ΣAMA (NAMA) of its fractions was comparable with the anti-RMtb NAMA of the still maceration extracts and significantly higher than the anti-SMtb and anti-RMtb NAMAs of every other ethanol extract and serial extract and fraction. Hexane extracted, from decoction, material having 55.17% and 92.62% of antituberculosis activity against SMtb and RMtb, respectively. Although the mycobactericidal activity of decoction is undetectable; its efficacy in extracting F. cernua active metabolites against M. tuberculosis is substantially greater than almost all pharmacognostic methods.

Journal Article

Abstract  From a screening on agar plates with bis(benzoyloxyethyl) terephthalate (3PET), a Bacillus subtilis p-nitrobenzylesterase (BsEstB) was isolated and demonstrated to hydrolyze polyethyleneterephthalate (PET). PET-hydrolase active strains produced clearing zones and led to the release of the 3PET hydrolysis products terephthalic acid (TA), benzoic acid (BA), 2-hydroxyethyl benzoate (HEB), and mono-(2-hydroxyethyl) terephthalate (MHET) in 3PET supplemented liquid cultures. The 3PET-hydrolase was isolated from non-denaturating polyacrylamide gels using fluorescein diacetate (FDA) and identified as BsEstB by LC-MS/MS analysis. BsEstB was expressed in Escherichia coli with C-terminally fused StrepTag II for purification. The tagged enzyme had a molecular mass of 55.2 kDa and a specific activity of 77 U/mg on p-nitrophenyl acetate and 108 U/mg on p-nitrophenyl butyrate. BsEstB was most active at 40°C and pH 7.0 and stable for several days at pH 7.0 and 37°C while the half-life times decreased to 3 days at 40°C and only 6 h at 45°C. From 3PET, BsEstB released TA, MHET, and BA, but neither bis(2-hydroxyethyl) terephthalate (BHET) nor hydroxyethylbenzoate (HEB). The k(cat) values decreased with increasing complexity of the substrate from 6 and 8 (s-1) for p-nitrophenyl-acetate (4NPA) and p-nitrophenyl-butyrate (4NPB), respectively, to 0.14 (s-1) for bis(2-hydroxyethyl) terephthalate (BHET). The enzyme hydrolyzed PET films releasing TA and MHET with a concomitant decrease of the water-contact angle (WCA) from 68.2° ± 1.7° to 62.6° ± 1.1° due to formation of novel hydroxyl and carboxyl groups. These data correlated with a fluorescence emission intensity increase seen for the enzyme treated sample after derivatization with 2-(bromomethyl)naphthalene. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011.

Journal Article

Abstract  In the present study, we evaluated the role of the defense-related gene OCP3 in callose deposition as a response to two necrotrophic fungal pathogens, Botrytis cinerea and Plectosphaerella cucumerina. ocp3 plants exhibited accelerated and intensified callose deposition in response to fungal infection associated with enhanced disease resistance to the two pathogens. A series of double mutant analyses showed potentiation of callose deposition and the heightened disease resistance phenotype in ocp3 plants required the plant hormone abscisic acid (ABA) and the PMR4 gene encoding a callose synthase. This finding was congruent with an observation that ocp3 plants exhibited increased ABA accumulation, and ABA was rapidly synthesized following fungal infection in wild-type plants. Furthermore, we determined that potentiation of callose deposition in ocp3 plants, including enhanced disease resistance, also required jasmonic acid (JA) recognition though a COI1 receptor, however JA was not required for basal callose deposition following fungal infection. In addition, potentiation of callose deposition in ocp3 plants appeared to follow a different mechanism than that proposed for callose β-amino-butyric acid (BABA)-induced resistance and priming, because ocp3 plants responded to BABA-induced priming for callose deposition and induced resistance of a magnitude similar to that observed in wild-type plants. Our results point to a model in which OCP3 represents a specific control point for callose deposition regulated by JA yet ultimately requiring ABA. These results provide new insights into the mechanism of callose deposition regulation in response to pathogen attack; however the complexities of the processes remain poorly understood.

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