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1.
Data Brief ; 49: 109319, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37435141

RESUMO

Here we present a compendium of 212 photographs of archaeological soils and sediments thin sections (micrographs) from the backfill of the Sennacherib Assyrian canal system of Northern Mesopotamia. The micrographs were produced using an optical petrographic microscope (Olympus BX41) mounting a digital camera (Olympus E420) for image acquisition. The dataset is composed of two folders containing (1) every micrograph in full resolution JPEG, and (2) a PDF file with scale bars and brief captions for each one. The dataset represents a photographic comparison collection for individuals working on similar geoarchaeological contexts and can be used for the composition of figures in novel publications, as well as being the first example of published large compendium for shared use in the field of archaeology.

2.
Sci Rep ; 13(1): 7683, 2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37202432

RESUMO

Tells are multi-layered, archaeological mounds representing anthropogenic landforms common in arid regions. In such contexts, the preservation of the archaeological record is mined by ongoing climate changes, shift in land use, and intense human overgrazing. Such natural and human-driven factors tune the response of archaeological soils and sediments to erosion. Geomorphology offers a plethora of tools for mapping natural and anthropogenic landforms and evaluating their response to unremitting weathering, erosional and depositional processes. Here, we present a geomorphological investigation on two anthropogenic mounds in the Kurdistan Region of Iraq, with a special focus on the ongoing erosional processes mining their slope stability and threatening the preservation of the local archaeological landscape. Applying the revised universal soil loss equation model for soil loess derived from UAV imagery and implemented with geoarchaeological investigation, we assess the erosion rate along anthropogenic mounds and estimate the risk of losing archaeological deposits. We argue that a large-scale application of our approach in arid and semi-arid regions may improve our ability to (i) estimate the rate of soil and/or archaeological sediments loss, (ii) propose mitigation strategies to prevent the dismantling of the archaeological record, and (iii) schedule archaeological operations in areas of moderate to extreme erosion risk.

3.
Sci Rep ; 13(1): 45, 2023 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-36639410

RESUMO

In the first millennia of the Holocene, human communities in the Fertile Crescent experienced drastic cultural and technological transformations that modified social and human-environments interactions, ultimately leading to the rise of complex societies. The potential influence of climate on this "Neolithic Revolution" has long been debated. Here we present a speleothem record from the Kurdistan Region of Iraq, covering from Early Neolithic to Early Chalcolithic periods (~ 11 to 7.3 ka, 9000-5300 BCE). The record reveals the influence of the Siberian High on regional precipitation, and shows large hydroclimatic variability at the multicentennial scale. In particular, it highlights wetter conditions between 9.7 and 9.0 ka, followed by an abrupt reduction of precipitation between 9.0 and 8.5 ka, and a wetter interval between 8.5 and 8.0 ka. A comparison with regional and local archaeological data demonstrates an influence of recorded hydroclimatic changes on settlement patterns (size, distribution, permanent vs. seasonal occupation) and on the exploitation of water resources by Neolithic to Chalcolithic populations. Our record does not show prominent hydroclimatic changes at 9.3 and 8.2 ka, thus not supporting direct influence of such rapid and widespread events on the process of Neolithization and its cultural dispersal.


Assuntos
Clima , Recursos Hídricos , Humanos , Tecnologia , Iraque , Arqueologia
4.
Bioengineering (Basel) ; 9(12)2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36550984

RESUMO

With regards to oil-based diesel fuel, the adoption of bio-derived diesel fuel was estimated to reduce CO2 emissions by approximately 75%, considering the whole life cycle. In this paper, we present a novel continuous-flow process able to transfer an equimolar amount of CO2 (through urea) to glycerol, producing glycerol carbonate. This represents a convenient tool, able to both improve the efficiency of the biodiesel production through the conversion of waste streams into added-value chemicals and to beneficially contribute to the whole carbon cycle. By means of a Design of Experiments approach, the influence of key operating variables on the product yield was studied and statistically modeled.

5.
Mar Drugs ; 20(9)2022 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-36135774

RESUMO

Increasing evidence in the field of bioprospection fosters the necessity of studying poorly investigated poisonous marine invertebrates to expand knowledge on animal venom biology. Among marine annelids, amphinomid fireworms are notorious for their bearded trunk equipped with a powerful stinging capacity. Here, a methodological workflow based on analytical chemistry techniques (compound isolation followed by mass spectrometry and spectroscopy analyses) was applied to gain new insights, leading to the identification and structural elucidation of an array of natural products from Mediterranean specimens of Hermodice carunculata. Eight betaine-derived unprecedented compounds, named "carunculines", were detected, bearing two terminal ammonium groups tri-and disubstituted at the Cα (A, B) and a series of different alkyl chains (I-VIII). The mixture of chemicals was found in all the body parts of H. carunculata, supporting a mechanism of action triggered by their vehiculation inside the dorsal chaetae, and subsequent injection when chaetae break off on contact. Preliminary investigations to understand adaptive features were also performed, showing a trend in carunculine abundance that fits into the evolutionary history of these worms. These findings shed light on the chemical ecology of amphinomids, giving reasons for the success of H. carunculata in benthic environments and providing promising novel metabolites for biotechnological implications.


Assuntos
Compostos de Amônio , Anelídeos , Produtos Biológicos , Poliquetos , Animais , Betaína , Produtos Biológicos/farmacologia
6.
Plants (Basel) ; 11(18)2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36145791

RESUMO

Plants have long been considered passive, static, and unchanging organisms, but this view is finally changing. More and more knowledge is showing that plants are aware of their surroundings, and they respond to a surprising variety of stimuli by modifying their growth and development. Plants extensively communicate with the world around them, above and below ground. Although communication through mycorrhizal networks and Volatile Organic Compounds has been known for a long time, acoustic perception and communication are somehow a final frontier of research. Perhaps surprisingly, plants not only respond to sound, they actually seem to emit sound as well. Roots emit audible clicks during growth, and sounds are emitted from xylem vessels, although the nature of these acoustic emissions still needs to be clarified. Even more interesting, there is the possibility that these sounds carry information with ecological implications, such as alerting insects of the hydration state of a possible host plant, and technological implications as well. Monitoring sound emissions could possibly allow careful monitoring of the hydration state of crops, which could mean significantly less water used during irrigation. This review summarizes the current knowledge on sound perception communication in plants and illustrates possible implications and technological applications.

7.
Sci Rep ; 12(1): 13530, 2022 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-35941267

RESUMO

During the last century, Grotta Romanelli (Southern Italy) has been a reference site for the European Late Pleistocene stratigraphy, due to its geomorphological setting and archaeological and palaeontological content. The beginning of the sedimentation inside the cave was attributed to the Last Interglacial (MISs 5e) and the oldest unearthed evidence of human occupation, including remains of hearths, was therefore referred to the Middle Palaeolithic. Recent surveys and excavations produced new U/Th dates, palaeoenvironmental interpretation and a litho-, morpho- and chrono-stratigraphical reassessment, placing the oldest human frequentation of the cave between MIS 9 and MIS 7, therefore embracing Glacial and Interglacial cycles. These new data provide evidence that the sea reached the cave during the Middle Pleistocene and human occupation occurred long before MISs 5e and persisted beyond the Pleistocene- Holocene boundary.


Assuntos
Arqueologia , Fósseis , Cavernas , Humanos , Itália , Paleontologia
8.
Plant Signal Behav ; 16(8): 1919836, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-33910490

RESUMO

In a very recent book called Sensory Biology of Plants, published by renowned publisher Springer Nature, the authors stated that the scientific literature gathered so far regarding knowledge around the field of Plant Acoustics allows us to divert the focus from the question "whether plants perceive sound" toward the questions "how and why they are doing it" Some phenomena are well known: roots perceive the sound of flowing water and display a sound-mediated growth toward the water source, while the buzz pollination process allows plants to minimize the pollen lost and maximize which is collected by true pollinators. But plants are far more perceptive and responsive to their environment than we generally consider them to be, and they are communicating far more information than we realize if we only took all their signals (VOCs, sound, exudates, etc.) into a greater picture. Could Volatile Organic Compounds (VOCs) be involved in mediating more responses than we imagine? VOC synthesis and release is known to be elicited also by electrical signals caused by mechanical stimuli, touching and wounding being among these, serving as info-chemicals in the communication between plants ("eavesdropping"), and within the organs of the same plant, in order for it to get synchronized with its surroundings. This paper is an overview of the discoveries around plant perception with a focus on the link between mechanical stimuli, as sound vibrations are, and changes in plant physiology leading to VOC emission.


Assuntos
Acústica , Fenômenos Fisiológicos Vegetais , Plantas/metabolismo , Som , Compostos Orgânicos Voláteis/metabolismo , Percepção , Desenvolvimento Vegetal , Polinização , Água
9.
Foods ; 10(2)2021 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-33572474

RESUMO

The Mediterranean-style diet is rich in fruit and vegetables and has a great impact on the prevention of major chronic diseases, such as cardiovascular diseases and cancer. In this work we investigated the ability of spinach extracts obtained by different extraction methods and of the single main components of the phytocomplex, alone or mixed, to modulate proliferation, antioxidant defense, and genotoxicity of HT29 human colorectal cells. Spinach extracts show dose-dependent activity, increasing the level of intracellular endogenous reactive oxygen species (ROS) when tested at higher doses. In the presence of oxidative stress, the activity is related to the oxidizing agent involved (H2O2 or menadione) and by the extraction method. The single components of the phytocomplex, alone or mixed, do not alter the intracellular endogenous level of ROS but again, in the presence of an oxidative insult, the modulation of antioxidant defense depends on the oxidizing agent used. The application of the phytocomplex extracts seem to be more effective than the application of the single phytocomplex components.

10.
Plant Signal Behav ; 15(12): 1828674, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33048612

RESUMO

Life evolved in an acoustic world. Sound is perceived in different ways by the species that inhabit the Planet. Among organisms, also some algal species seem to respond to sound stimuli with increased cell growth and productivity. The purpose of this Short Communication is to provide an overview of the current literature about various organisms and sound, with particular attention to algal organisms, which, when subjected to sound applications, can change their metabolism accordingly.


Assuntos
Microalgas/fisiologia , Percepção , Plantas/metabolismo , Alga Marinha/fisiologia , Som , Animais , Humanos
11.
Nat Prod Res ; 34(4): 567-574, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30317865

RESUMO

The antibacterial activity of Pimpinella anisum L., Cinnamomum zeylanicum, Syzygium aromaticum, and Cuminum cyminum L. essential oils (EOs) against some common pathogenic microorganisms (Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 14990, Enterococcus faecalis ATCC 29212, Streptococcus pyogenes ATCC 1915, Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 27853, Aeromonas hydrophila ATCC 7966, Proteus mirabilis ATCC 10005, Klebsiella pneumoniae ATCC 13883, and Candida albicans ATCC 10231) and their biofilms was studied. The EOs inhibitory effects were evaluated by both Agar Well Diffusion assay and Minimum Inhibitory Concentration (MIC) determination. The most active EOs, cinnamon and cloves, were also tested on 18, 24, 48, 72 hours mature biofilms. Cinnamon and cloves exhibited the best results showing a significant activity against all the tested bacteria. Concerning biofilm, results suggest that Cinnamomum zeylanicum oil may be a useful approach to impair the biofilm produced by the tested Gram-negative bacteria. [Formula: see text].


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Óleos Voláteis/farmacologia , Especiarias , Antibacterianos/isolamento & purificação , Candida albicans/efeitos dos fármacos , Cinnamomum zeylanicum/química , Cuminum/química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Óleos Voláteis/uso terapêutico , Pseudomonas aeruginosa/efeitos dos fármacos , Syzygium/química
12.
Molecules ; 24(22)2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31766211

RESUMO

Triterpenoids are natural compounds synthesized by plants through cyclization of squalene, known for their weak anti-inflammatory activity. 2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid (CDDO), and its C28 modified derivative, methyl-ester (CDDO-Me, also known as bardoxolone methyl), are two synthetic derivatives of oleanolic acid, synthesized more than 20 years ago, in an attempt to enhance the anti-inflammatory behavior of the natural compound. These molecules have been extensively investigated for their strong ability to exert antiproliferative, antiangiogenic, and antimetastatic activities, and to induce apoptosis and differentiation in cancer cells. Here, we discuss the chemical properties of natural triterpenoids, the pathways of synthesis and the biological effects of CDDO and its derivative CDDO-Me. At nanomolar doses, CDDO and CDDO-Me have been shown to protect cells and tissues from oxidative stress by increasing the transcriptional activity of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2). At doses higher than 100 nM, CDDO and CDDO-Me are able to modulate the differentiation of a variety of cell types, both tumor cell lines or primary culture cell, while at micromolar doses these compounds exert an anticancer effect in multiple manners; by inducing extrinsic or intrinsic apoptotic pathways, or autophagic cell death, by inhibiting telomerase activity, by disrupting mitochondrial functions through Lon protease inhibition, and by blocking the deubiquitylating enzyme USP7. CDDO-Me demonstrated its efficacy as anticancer drugs in different mouse models, and versus several types of cancer. Several clinical trials have been started in humans for evaluating CDDO-Me efficacy as anticancer and anti-inflammatory drug; despite promising results, significant increase in heart failure events represented an obstacle for the clinical use of CDDO-Me.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/síntese química , Ácido Oleanólico/farmacologia , Triterpenos/química , Antineoplásicos/química , Redes e Vias Metabólicas , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Estrutura Molecular , Ácido Oleanólico/química
13.
Biomolecules ; 9(2)2019 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-30720723

RESUMO

Fruits and vegetables are a good source of potentially biologically active compounds. Their regular consumption in the human diet can help reduce the risk of developing chronic diseases such as cardiovascular diseases and cancer. Plants produce additional chemical substances when subject to abiotic stress or infected by microorganisms. The phytochemical profile of spinach leaves (Spinaciaoleracea L.), which is a vegetable with widely recognized health-promoting activity, has been affected by applying root hypoxic and re-oxygenation stress during plant growth. Leaf juice at different sampling times has been subject to liquid chromatography mass spectrometry (LC-MSn) analysis and tested on the human colorectal adenocarcinoma cell line HT29 by using the Comet assay. The cells were previously treated with H2O2 to simulate the presence of an oxidative stress (as in colon cancer condition) and the leaf juice application resulted in a significant antioxidant and protective in vitro effect. The duration of the hypoxic/re-oxygenation stress imposed on the plant reflects the antioxidant leaf juice content. After hypoxic stress (24 hours) and reoxygenation (2 hours), we show a decrease (50%) of the relative abundance of the principal identified antioxidant molecules but a higher antioxidant activity of the spinach juice on HT29 cells (20%). Data shows a complex relation between plant growing conditions and the modulation of secondary metabolites content in leaf juice that results in different chemo-protective activities in colon cancer cells.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Sucos de Frutas e Vegetais/análise , Oxigênio/metabolismo , Extratos Vegetais/farmacologia , Spinacia oleracea/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antioxidantes/química , Antioxidantes/isolamento & purificação , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Físico-Química , Cromatografia Líquida , Ensaios de Seleção de Medicamentos Antitumorais , Células HT29 , Humanos , Espectrometria de Massas , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação
14.
Bioresour Technol ; 244(Pt 2): 1261-1268, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28483355

RESUMO

In this study a photobioreactor prototype is presented for the culture growth of microalgae model organism Neochloris oleoabundans by using chicken manure waste as feedstock along with the optimum combination of led light wavelengths and light intensity. Particularly interesting results are observed on the strains fed by chicken manure medium under the proper combination of red and blue LED light illumination, the microalgal growth resulted comparable with the strains fed by the costly commercial microalgal growth medium (BG 11 medium). Cell concentration, optical density, growth rate, cell size, total lipid and photosynthetic pigment content have been monitored during a time-course experiment. The data suggest that there are difficulties due to white light diffusion into the dark chicken medium, which leads to a generally lower intensity scattered along all wavelengths; blue or combined red and blue lights resulted in a higher irradiation density, affecting microalgae cell growth.


Assuntos
Clorófitas , Esterco , Fotobiorreatores , Animais , Biomassa , Galinhas , Luz , Microalgas
15.
Biotechnol Biofuels ; 9: 259, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27933101

RESUMO

BACKGROUND: The ability of some microorganisms to accumulate lipids is well known; however, only recently the number of studies on microbial lipid biosynthesis for obtaining oleochemical products, namely biofuels and some building blocks for chemistry, is rapidly and spectacularly increased. Since 1990s, some oleaginous yeasts were studied for their ability to accumulate lipids up to 60-70% of their dry weight. Due to the vast array of engineering techniques currently available, the recombinant DNA technology was the main approach followed so far for obtaining lipid-overproducing yeasts, mainly belonging to the Yarrowia lipolytica. However, an alternative approach can be offered by worldwide diversity as source of novel oleaginous yeasts. Lipogenic aptitude of a number of yeast strains has been reviewed, but many of these studies utilized a limited number of species and/or different culture conditions that make impossible the comparison of different results. Accordingly, the lipogenic aptitude inside the yeast world is still far from being fully explored, and finding new oleaginous yeast species can acquire a strategic importance. RESULTS: Holtermanniella wattica, Leucosporidium creatinivorum, Naganishia adeliensis, Solicoccozyma aeria, and Solicoccozyma terricola strains were selected as a result of a large-scale screening on 706 yeasts (both Ascomycota and Basidiomycota). Lipid yields and fatty acid profiles of selected strains were evaluated at 20 and 25 °C on glucose, and on glycerol, xylose, galactose, sucrose, maltose, and cellobiose. A variable fatty acid profile was observed in dependence of both temperature and different carbon sources. On the whole, L. creatinivorum exhibited the highest performances: total lipid yield (YL) >7 g/l on glucose and glycerol, % of intracellular lipids on cell biomass (YL/DW) >70% at 20 °C on glucose, lipid coefficient (YL/Glu) around 20% on glucose, and daily productivity (YL/d) on glucose and sucrose >1.6 g/(l*d). CONCLUSIONS: This study provides some meaningful information about the lipogenic ability of some yeast species. Variable lipid yields and fatty acid profiles were observed in dependence of both temperature and different carbon sources. L. creatinivorum exhibited the highest lipogenic performances.

16.
Blood Cells Mol Dis ; 58: 6-12, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27067481

RESUMO

Βeta-thalassemia, is a hemoglobinopathy characterized by reduced beta-globin chain synthesis, leading to imbalanced globin chain production, ineffective erythropoiesis and anemia. Increasing gamma-globin gene expression is a promising therapeutic approach as it reduces this imbalance by combining with the excess alpha globin chains and producing fetal hemoglobin (HbF). Furthermore, increased iron absorption and repeated blood transfusions lead to iron overload and tissue damage secondary to reactive oxygen species. Compounds exhibiting both antioxidant and HbF inducing activities are, therefore, highly desirable therapeutic agents. Resveratrol, a natural phytoalexin, combines these two activities but is also cytotoxic. Nine hydroxystilbenic resveratrol derivatives were synthesized in an attempt to identify compounds that retain the HbF-inducing and antioxidant activities of resveratrol but exhibit reduced cytotoxicity. Three derivatives (P1, P4 and P11) exhibited similar hemoglobin-inducing properties to resveratrol in K562 cells, however, only P11 showed reduced cytotoxicity. All three derivatives demonstrated variable HbF-inducing activity in primary erythroid progenitor cells from healthy donors. Resveratrol and P11 increased HbF induction significantly, with P11 having the highest activity. Additionally, P4 significantly increased progenitor numbers. A combinatorial treatment in K562 cells using resveratrol and decitabine resulted in a statistically significant increase in hemoglobin-inducing activity only above the level shown by resveratrol alone.


Assuntos
Antioxidantes/farmacologia , Hemoglobina Fetal/metabolismo , Estilbenos/farmacologia , Antioxidantes/química , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Células Precursoras Eritroides/citologia , Células Precursoras Eritroides/efeitos dos fármacos , Humanos , Células K562 , Resveratrol , Estilbenos/química
17.
Molecules ; 20(6): 10377-98, 2015 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-26053491

RESUMO

The rising consumer requests for natural flavors and fragrances have generated great interest in the aroma industry to seek new methods to obtain fragrance and flavor compounds naturally. An alternative and attractive route for these compounds is based on bio-transformations. In this review, the application of biocatalysis by Non Conventional Yeasts (NCYs) whole cells for the production of flavor and fragrances is illustrated by a discussion of the production of different class of compounds, namely Aldehydes, Ketones and related compounds, Alcohols, Lactones, Terpenes and Terpenoids, Alkenes, and Phenols.


Assuntos
Biocatálise , Aromatizantes/metabolismo , Leveduras/metabolismo , Biotransformação
18.
J Sci Food Agric ; 95(3): 490-6, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24862450

RESUMO

BACKGROUND: In the human diet, the consumption of fresh fruits and vegetables is important in maintaining good health and in preventing chronic diseases. It is known that plant-derived food is a powerful source of chemopreventive molecules, i.e. antioxidants, and spinach (Spinacia oleracea L., Chenopodiaceae) possesses a wide range of metabolites with such biological activity. Plant stress response could lead to the production of metabolites with high value for human health and this could be a tool to enhance the production of molecules with antioxidant activity in plants. RESULTS: Data reported in this paper confirm the antioxidant properties of spinach plants, and show a strong antiproliferative activity of leaf extract on HT-29 human cell line. Besides, the hypoxic stress seems to affect the pool of antioxidant molecules present in spinach leaves, as verified by means of HPLC-MS/MS analysis and the aluminium chloride and ABTS assays. CONCLUSION: Our findings represent a basis for improving the biological and pharmacological properties of spinach plants, including the use of different growth conditions to modulate the phytocomplex profile of spinach.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Antioxidantes/uso terapêutico , Neoplasias/tratamento farmacológico , Oxigênio , Extratos Vegetais/uso terapêutico , Spinacia oleracea , Estresse Fisiológico , Adaptação Fisiológica , Adenocarcinoma/tratamento farmacológico , Agricultura/métodos , Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Benzotiazóis/metabolismo , Neoplasias do Colo/tratamento farmacológico , Células HT29 , Humanos , Oxigênio/metabolismo , Fitoterapia , Extratos Vegetais/farmacologia , Folhas de Planta , Spinacia oleracea/metabolismo , Ácidos Sulfônicos/metabolismo , Verduras
19.
Molecules ; 18(5): 5736-48, 2013 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-23681058

RESUMO

As part of a program aiming at the selection of yeast strains which might be of interest as sources of natural flavours and fragrances, the bioreduction of (4R)-(-)-carvone and (1R)-(-)-myrtenal by whole-cells of non-conventional yeasts (NCYs) belonging to the genera Candida, Cryptococcus, Debaryomyces, Hanseniaspora, Kazachstania, Kluyveromyces, Lindnera, Nakaseomyces, Vanderwaltozyma and Wickerhamomyces was studied. Volatiles produced were sampled by means of headspace solid-phase microextraction (SPME) and the compounds were analysed and identified by gas chromatography-mass spectroscopy (GC-MS). Yields (expressed as % of biotransformation) varied in dependence of the strain. The reduction of both (4R)-(-)-carvone and (1R)-(-)-myrtenal were catalyzed by some ene-reductases (ERs) and/or carbonyl reductases (CRs), which determined the formation of (1R,4R)-dihydrocarvone and (1R)-myrtenol respectively, as main flavouring products. The potential of NCYs as novel whole-cell biocatalysts for selective biotransformation of electron-poor alkenes for producing flavours and fragrances of industrial interest is discussed.


Assuntos
Antineoplásicos Fitogênicos , Aromatizantes , Monoterpenos , Terpenos , Leveduras/metabolismo , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/metabolismo , Antineoplásicos Fitogênicos/farmacologia , Monoterpenos Bicíclicos , Biotransformação , Monoterpenos Cicloexânicos , Aromatizantes/química , Aromatizantes/metabolismo , Monoterpenos/química , Monoterpenos/metabolismo , Monoterpenos/farmacologia , Terpenos/química , Terpenos/metabolismo , Terpenos/farmacologia
20.
Bioresour Technol ; 121: 290-7, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22858498

RESUMO

Response surface methodology was applied in optimizing the asymmetric bioreduction of (4S)-(+)-carvone to dihydrocarvone (with low incidence of unsought side reactions) by using whole-cells of Cryptococcus gastricus. A factorial design (2(5)) including five independent variables was performed: X(1)=incubation time; X(2)=pH; X(3)=amount of whole-cells; X(4)=concentration of (4S)-(+)-carvone; X(5)=concentration of cofactor-recycling system. The utilization of glucose and glycerol as cofactor-recycling systems was checked. On the basis of the results of factorial design, three independent variables (X(1), X(3) and X(4)) out of five were further selected for performing a central composite design (CCD). First and second order polynomial equations obtained by CCD were used to select the optimal values of independent variables in order to maximize the bioreduction yield of (4S)-(+)-carvone and, at the same time, to minimize the occurrence of side reactions (i.e. further reduction of dihydrocarvone to dihydrocarveol).


Assuntos
Cryptococcus/metabolismo , Microbiologia Industrial/métodos , Modelos Estatísticos , Monoterpenos/metabolismo , Monoterpenos Cicloexânicos , Cromatografia Gasosa-Espectrometria de Massas , Oxirredução , Microextração em Fase Sólida
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