249 research outputs found

    Optimiranje fizikalno-kemijskih parametara, djelomično pročišćavanje i karakterizacija izvanstanične alkalne lipaze iz novog soja plijesni Curvularia sp. DHE 5

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    Thirty isolated fungal strains were screened for lipase production using Phenol Red plates, containing tributyrin as lipidic substrate, and a novel fungus identified genetically as Curvularia sp. DHE 5 was found as the most prominent strain. Various agro-industrial substrates were evaluated as inert supports for lipase production in solid-state fermentation. The highest yield of lipase ((83.4±2.2) U/g on dry mass basis) was reported with wheat bran medium after seven days of fermentation at pH=7.0, temperature of 30 °C, 70 % moisture content, inoculum size of 1.27·107 spore/mL and 2 % olive oil as an inducer. Supplementation of the medium with 0.05 % KCl as an ion source further increased lipase production to (88.9±1.2) U/g on dry mass basis. The enzyme was partially purified through ammonium sulphate fractionation (40 %) followed by dialysis, and its optimum pH and temperature were reported at 8.0 and 50 °C, respectively, with remarkable pH and thermal stability.U radu je ispitana proizvodnja lipaze iz 30 izolata plijesni na podlozi s tributirinom pomoću fenolnog crvenila, pri čemu se najviše istaknuo izolat koji je genetički identificiran kao novi soj plijesni Curvularia sp. DHE 5. Ispitana je mogućnost korištenja različitog agroindustrijskog otpada kao inertnih podloga za proizvodnju lipaze fermentacijom na čvrstoj podlozi. Najveći prinos lipaze od (83,4±2,2) jedinica po gramu suhe tvari dobiven je u podlozi s pšeničnim mekinjama nakon sedam dana fermentacije pri pH-vrijednosti od 7,0; temperaturi od 30 °C, 70 %-tnom udjelu vlage, veličini inokuluma od 1,27·107 spora po mililitru i s dodatkom 2 %-tnog maslinovog ulja. Dodatak 0,05 % KCl kao izvora iona dodatno je potaknuo proizvodnju lipaze na 88,9±1,2 jedinica po gramu suhe tvari. Enzim je djelomično pročišćen (40 %) frakcioniranjem pomoću amonijeva sulfata i dijalizom, te se pokazao izuzetno stabilinim, s optimalnom pH-vrijednosti od 8,0 i optimalnom temperaturom od 50 °C

    DNA Fingerprinting, Chemical Composition, Antitumor and Antimicrobial Activities of the Essential Oils and Extractives of four Annona Species from Egypt

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    The leaf essential oils of four members of the Annonaceae grown in Egypt (namely; Annona cherimola, A. squamosa, A. muricata and A. glabra) have been obtained by hydrodistillation and analyzed by GC-MS in order to compare and contrast the volatile chemical compositions of these species.  The essential oils were screened for in-vitro cytotoxic activity against breast cancer (MCF-7), colon cancer (CACO) and liver cancer (HEPG2) cell lines and antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeuroginosa, Aspergillus flavus and Candida albicans. beta-elemene (25.02%), beta-caryophyllene (37.11%), bicycloelemene (23.58%) and and beta-gurjunene (42.49%), were the major constituents of Annona cherimola, A. squamosa, A. muricata and A. glabra, respectively. Ethanol extracts showed highly significant cytotoxic activities (low IC50) much more than results displayed by essential oils on breast (MCF-7), colon (CACO) and liver (HEPG2) carcinoma cell lines. Relative to breast carcinoma cell line (MCF-7), The IC50 values of ethanol extracts were 3.43, 3.89 and 4.34 ?g/ml for A. cherimola, A. squamosa and A. muricata ethanol extractives respectively. While colon carcinoma cell line (CACO) displayed IC50 values 2.82, 2.97, 3.58 and 3.89 ?g/ml for A. muricata, A. cherimola, A. glabra and A. squamosa, respectively. Liver carcinoma cell line (HEPG2) exhibited IC50 valus of 3.12, 3.43 and 3.73 for A. squamosa, A. muricata and A. cherimola, respectively. Three of the four leaf essential oils showed notable invitro cytotoxic activity. Essential oils of A. glabra, A. muricata and A. squamosa showed moderate cytotoxic activities with IC50 values ranging from 12.35 to 24.21?g/ml. While the essential oils of A. cherimola showed IC50 values ranging from 7.67 to 9.22?g/ml. Leaf oils and ethanol extractives showed appreciable antibmicobial activity with variable MIC ranging from 30 to 315µg/ml. These findings suggest that A. cherimola essential oil and ethanol extract have great potential as a natural medicine for cancers and microbial infections. Keywords:Annona cherimola; A. squamosa;, A. muricata ; A. glabra;   Annonaceae;   DNA, essential   oil   composition; cytotoxicity; antimicobia

    DNA Fingerprinting, Chemical Composition, Antitumor and Antimicrobial Activities of the Essential Oils and Extractives of four Annona Species from Egypt

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    The leaf essential oils of four members of the Annonaceae grown in Egypt (namely; Annona cherimola, A. squamosa, A. muricata and A. glabra) have been obtained by hydrodistillation and analyzed by GC-MS in order to compare and contrast the volatile chemical compositions of these species.  The essential oils were screened for in-vitro cytotoxic activity against breast cancer (MCF-7), colon cancer (CACO) and liver cancer (HEPG2) cell lines and antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeuroginosa, Aspergillus flavus and Candida albicans. beta-elemene (25.02%), beta-caryophyllene (37.11%), bicycloelemene (23.58%) and and beta-gurjunene (42.49%), were the major constituents of Annona cherimola, A. squamosa, A. muricata and A. glabra, respectively. Ethanol extracts showed highly significant cytotoxic activities (low IC50) much more than results displayed by essential oils on breast (MCF-7), colon (CACO) and liver (HEPG2) carcinoma cell lines. Relative to breast carcinoma cell line (MCF-7), The IC50 values of ethanol extracts were 3.43, 3.89 and 4.34 ?g/ml for A. cherimola, A. squamosa and A. muricata ethanol extractives respectively. While colon carcinoma cell line (CACO) displayed IC50 values 2.82, 2.97, 3.58 and 3.89 ?g/ml for A. muricata, A. cherimola, A. glabra and A. squamosa, respectively. Liver carcinoma cell line (HEPG2) exhibited IC50 valus of 3.12, 3.43 and 3.73 for A. squamosa, A. muricata and A. cherimola, respectively. Three of the four leaf essential oils showed notable invitro cytotoxic activity. Essential oils of A. glabra, A. muricata and A. squamosa showed moderate cytotoxic activities with IC50 values ranging from 12.35 to 24.21?g/ml. While the essential oils of A. cherimola showed IC50 values ranging from 7.67 to 9.22?g/ml. Leaf oils and ethanol extractives showed appreciable antibmicobial activity with variable MIC ranging from 30 to 315µg/ml. These findings suggest that A. cherimola essential oil and ethanol extract have great potential as a natural medicine for cancers and microbial infections. Keywords:Annona cherimola; A. squamosa;, A. muricata ; A. glabra;   Annonaceae;   DNA, essential   oil   composition; cytotoxicity; antimicobia

    5-azacytidine promotes microspore embryogenesis initiation by decreasing global DNA methylation,but prevents subsequent embryo development in rapeseed and barley

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    17 p.-10 fig.Microspores are reprogrammed by stress in vitro toward embryogenesis. This process is an important tool in breeding to obtain double-haploid plants. DNA methylation is a major epigenetic modification that changes in differentiation and proliferation. We have shown changes in global DNA methylation during microspore reprogramming. 5-Azacytidine (AzaC) cannot be methylated and leads to DNA hypomethylation. AzaC is a useful demethylating agent to study DNA dynamics, with a potential application in microspore embryogenesis. This work analyzes the effects of short and long AzaC treatments on microspore embryogenesis initiation and progression in two species, the dicot Brassica napus and the monocot Hordeum vulgare. This involved the quantitative analyses of proembryo and embryo production, the quantification of DNA methylation, 5-methyl-deoxy-cytidine (5mdC) immunofluorescence and confocal microscopy, and the analysis of chromatin organization (condensation/decondensation) by light and electron microscopy. Four days of AzaC treatments (2.5 μM) increased embryo induction, response associated with a decrease of DNA methylation, modified 5mdC, and heterochromatin patterns compared to untreated embryos. By contrast, longer AzaC treatments diminished embryo production. Similar effects were found in both species, indicating that DNA demethylation promotes microspore reprogramming, totipotency acquisition, and embryogenesis initiation, while embryo differentiation requires de novo DNA methylation and is prevented by AzaC. This suggests a role for DNA methylation in the repression of microspore reprogramming and possibly totipotency acquisition. Results provide new insights into the role of epigenetic modifications in microspore embryogenesis and suggest a potential benefit of inhibitors, such as AzaC, to improve the process efficiency in biotechnology and breeding programs.Work supported by projects (references BFU2008-00203, BFU2011-23752, AGL2014-52028-R) funded by the Spanish Ministry of Economy and Competitiveness (MINECO) and the European Regional Development Fund (ERDF/FEDER). AAET is recipient of a predoctoral fellowship of the JAE-Pre Program of the Spanish National Research Council, CSIC (JAEPre2010-052), cofunded by ERDF/FEDER.Peer reviewe

    On Pairwise λ-Open Soft Sets and Pairwise Locally Closed Soft Sets

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    Kandil and his colleagues [10], introduced the notion of -closed soft set by involving -soft set and -closed soft set. In this paper, we give some additional properties of -closed soft sets. We also introduce and study a related new class of -spaces which lies between  and  . Moreover, we show that there exists a very important relation between the notion of -closed soft sets and the  property, ,  , . In addition, we offer the notion of -locally closed soft sets and we investigate a related new pairwise soft separation axiom  which is independent from . The relationships between the -closed soft sets and the -locally closed soft sets are obtained. Furthermore, we introduce the notion of -open soft sets and we construct supra soft topology associated with the class of -open soft sets and we present pairwise soft separation axioms related to such soft sets, namely . We provide some illustrative examples to support the results

    Controlling of crystal size and optical band gap of CdO nanopowder semiconductors by low and high Fe contents

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    The CdO:Fe nanopowder semiconductors were synthesized by the sol–gel calcination for the first time. The structural properties of Fe doped CdO samples were analyzed by AFM and XRD measurements. XRD patterns of the pure and Fe-doped CdO samples reveal that the pure and Fe doped CdO nanopowders are polycrystalline of cubic CdO structure. The crystallite size of undoped and Fe-doped CdO samples is changed unsystematically with a regular increase of Fe content. The optical band gaps of Fe doped CdO samples were determined for the first time by diffused reflectance measurements. The optical band gap of the samples is increased with the increase of Fe dopant inside the host matrix (CdO) up to 15 % followed by a decrease in its value. It is evaluated that Fe doped CdO nanopowder semiconductors can be producted by sol–gel calcination for advanced technological application

    Total Synthesis of Eleuthoside A; Application of Rh-Catalyzed Intramolecular Cyclization of Diazonaphthoquinone

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    The first total synthesis of (±)-eleutherol and eleuthoside A, the natural cytotoxic substances extracted from medicinal Indonesian plant, is described. First, the synthesis of (±)-eleutherol has been ­accomplished in nine steps starting from bromo methoxy aldehyde with the aid of diazo-transfer chemistry approach. Second, a metal-­catalyzed intramolecular cyclization reaction of the corresponding ­diazonaphthoquinone led to the desired eleuotherol, which served as a precursor to eleuthoside A. Then, several glycosidation routes, using different glucosyl donors, were experimented to reach effective O-glycosidation of eleutherol. The only successful strategy involved Koenigs–Knorr glycosidation using peracetyl glycosyl bromide in the presence of Ag2O and quinoline. This strategy furnished our desired acetylated glycoside of β-configuration, regioselectively. Finally, deacetylation and successive separation of diastereomers were conducted to give eleuthoside A
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