13 research outputs found
Lichens: might be considered as a source of gastroprotective molecules?
Indexación: Web of Science; ScieloABSTRACT
Lichens are symbiotic relationship between fungi and algae or cyanobacteria. Secondary metabolites from lichens are known as lichen substances. We investigated depsidone and depside from lichens 1-6 in the context of their action to prevent gastric ulcer on the model of HCl/ethanol in mice for the first time. Doses of 30 mg/kg of lichen substances 1-6 and positive control (lansoprazole) significantly diminished the lesion index compared with negative control (treated only with HCl/EtOH). Lobaric acid 1, atranorin 2 and psoromic acid 5 reduced the gastric lesions by 76%, 63% and 65%, while for variolaric acid 3, diffractaic acid 4 and perlatolic acid 6 their values were 32%, 14% and 45%, respectively. Our results suggest that lichens have potential as a suite of gastroprotective molecules.
Keywords: Lichens; depside; depsidone; gastric ulcer;http://ref.scielo.org/6949f
Biotransformation of ent-beyerenes with mucor plumbeus
Indexación: Web of Science; Scielo.ABSTRACT
The microbiological transformation of ent-beyer-15-en-18-ol 1 and ent-beyer-15-en-19-ol 2, using Mucorplumbeus, resulted in hydroxylated products. After nine days of incubation, 15β,16β-epoxide-ent-beyeran-7β,18-diol 3, ent-beyer-15-en-7p,19-diol 4 and 15β,16β-epoxide-ent-beyeran-7β,19-diol 5 were isolated. The metabolites were identified by spectroscopic methods.
Key Words:http://ref.scielo.org/47kx2
NEW BUTYROLACTONE FROM A MARINE-DERIVED FUNGUS ASPERGILLUS SP
Indexación: Web of Science; ScieloFour compounds that belong to two structure types, namely dibenzylbutyrolactone and sesterterpenoids, were obtained from the extract of the strain Aspergillus sp. (2P-22), isolated from a marine sponge, Cliona chilensis. Among them, compound 1 was identified as new, namely butylrolactone-VI. The structures of these compounds were characterized on the basis of spectroscopic data. Biological activities of these fungal metabolites, are described.http://ref.scielo.org/kbf7v
Improved sanitary landfill design using recirculation of anaerobically treated leachates: generation of advanced design criteria
Effect of dissolved oxygen and temperature on macromolecular composition and PHB storage of activated sludge
The macromolecular composition of activated sludge (lipids, intracellular proteins and intracellular polysaccharides) was studied together with its capacity to store macromolecules such as polyhydroxybutyrate (PHB) in a conventional activated sludge system fed with synthetic sewage water at an organic load rate of 1.0 kg COD/(m3·d), varying the dissolved oxygen (DO) and temperature. Six DO concentrations (0.8, 1.0, 1.5, 2.0, 2.5 and 8 mg/L) were studied at 20°C with a sludge retention time (SRT) of 6 days. In addition, four temperatures (10C, 15C, 20C and 30C) were assessed at constant DO (2 mg/L) with 2 days SRT in a second experimental run. The highest lipid content in the activated sludge was 95.6 mg/g VSS, obtained at 30°C, 2 mg/L of DO and a SRT of 2 days. The highest content of intracellular proteins in the activated sludge was 87.8 mg/g VSS, obtained at 20°C, 8 mg/L of DO and a SRT of 6 days. The highest content of intracellular polysaccharides in the activated sludge was 76.6 mg/g VSS, which was achieved at 20°C, a SRT of 6 days and a wide range of DO. The activated sludge PHB storage was very low for all the conditions studied. © 2014 Copyright Taylor & Francis Group, LLC.The authors wish to express their gratitude to Fondecyt Project No.1050787 (Chile) for its financial support.Peer Reviewe
Improved sanitary landfill design using recirculation of anaerobically treated leachates: generation of advanced design criteria
In Latin America, the most accepted disposal systems for Municipal
Solid Waste (MSW) are landfills, which nowadays have low rates of
stabilization. The objective of this study was to develop design
criteria for sanitary landfills which lead to a reduction in the
stabilization times of MSW, based on experiment results obtain from a
pre-pilot scale operation of two sanitary landfills (0.5 Ton), one with
recirculation of leachates treated in an anaerobic digester and the
other with recirculation of untreated leachates. This was complemented
by another pilot scale sanitary landfill (1440 Ton) with recirculation
of leaches treated in an anaerobic filter, and additionally by a
computer simulation of leachate generation through the water balance of
a theoretical cell of MSW (850 Ton), in which the initial humidity of
the MSW and the type of final cover were evaluated. The results
obtained on the pre-pilot scale indicate that recirculation of
anaerobically treated leachates, when compared to the recirculation of
untreated leachates, increased the rate of MSW stabilization,
projecting a stabilization time reduction of 72%. In the pilot sanitary
landfill an increase in the settling rate of around 200% was observed
when operating with the recirculation of anaerobically treated
leachates as opposed to operation without recirculation. The water
balance carried out on the theoretical cell of MSW demonstrated the
importance to leachate generation of both the initial landfill water
saturation and the type of final barrier. From these results it may be
stated that it is important for landfill design to maintain waste
humidity close to its field capacity along with an adequate leachate
application rate