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From all the valuable biomass extractives, polyphenols are a widespread group of secondary metabolites found in all plants, representing the most desirable phytochemicals due to their potential to be used as additives in food industry, cosmetics, medicine, and others fields. At present, there is an increased interest to recover them from plant of spontaneous flora, cultivated plant, and wastes resulted in agricultural and food industry. That is why many efforts have been made to provide a highly sensitive, efficiently, and eco‐friendly methods, for the extraction of polyphenols, according to the green chemistry and sustainable development concepts. Many extraction procedures are known with advantages and disadvantages. From these reasons, the aim of this article is to provide a comparative analysis regarding technical and economical aspects related to the most innovative extraction techniques studied in the last time: microwave‐assisted extraction (MAE), supercritical fluid extraction (SFE), and ultrasound‐assisted extraction (UAE). 相似文献
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José L. Hierro Özkan Eren Liana Khetsuriani Alecu Diaconu Katalin Török Daniel Montesinos Krikor Andonian David Kikodze Levan Janoian Diego Villarreal María E. Estanga‐Mollica Ragan M. Callaway 《Oikos》2009,118(4):529-538
Studying germination in the native and non‐native range of a species can provide unique insights into processes of range expansion and adaptation; however, traits related to germination have rarely been compared between native and non‐native populations. In a series of common garden experiments, we explored whether differences in the seasonality of precipitation, specifically, summer drought vs summer rain, and the amount and variation of annual and seasonal precipitation affect the germination responses of populations of an annual ruderal plant, Centaurea solstitialis, from its native range and from two non‐native regions with different climates. We found that seeds from all native populations, irrespective of the precipitation seasonality of the region in which they occurred, and non‐native populations from regions with dry summers displayed similarly high germination proportions and rates. In contrast, genotypes from the non‐native region with predominantly summer rain exhibited much lower germination fractions and rates. Also, percent germination was strongly correlated with variation in precipitation in winter, the season that follows germination for C. solstitialis. Specifically, germination was lower for native and non‐native populations experiencing greater variation in winter precipitation. This correlation, however, was greatly influenced by the non‐native region with summer rain, which also exhibited the greatest variation in winter precipitation among studied regions. These results suggest that rather than general climatic patterns, the degree of risk experienced at early developmental stages could exert an important control over the germination strategy of C. solstitialis populations in both native and non‐native ranges. Also, these findings reveal a largely unique germination response in C. solstitialis genotypes growing in the non‐native region with summer rain and high variation in winter precipitation. Our work raises the possibility that rapid adaptive changes in germination strategies may contribute to the success of globally distributed invaders. 相似文献
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Dana Bailey Isabelle Ruel Anouar Hafiane Haley Cochrane Iulia Iatan Matti Jauhiainen Christian Ehnholm Larbi Krimbou Jacques Genest 《Journal of lipid research》2010,51(4):785-797
The specifics of nascent HDL remodeling within the plasma compartment remain poorly understood. We developed an in vitro assay to monitor the lipid transfer between model nascent HDL (LpA-I) and plasma lipoproteins. Incubation of α-125I-LpA-I with plasma resulted in association of LpA-I with existing plasma HDL, whereas incubation with TD plasma or LDL resulted in conversion of α-125I-LpA-I to preβ-HDL. To further investigate the dynamics of lipid transfer, nascent LpA-I were labeled with cell-derived [3 H]cholesterol (UC) or [3H]phosphatidylcholine (PC) and incubated with plasma at 37°C. The majority of UC and PC were rapidly transferred to apolipoprotein B (apoB). Subsequently, UC was redistributed to HDL for esterification before being returned to apoB. The presence of a phospholipid transfer protein (PLTP) stimulator or purified PLTP promoted PC transfer to apoB. Conversely, PC transfer was abolished in plasma from PLTP−/− mice. Injection of 125I-LpA-I into rabbits resulted in a rapid size redistribution of 125I-LpA-I. The majority of [3H]UC from labeled r(HDL) was esterified in vivo within HDL, whereas a minority was found in LDL. These data suggest that apoB plays a major role in nascent HDL remodeling by accepting their lipids and donating UC to the LCAT reaction. The finding that nascent particles were depleted of their lipids and remodeled in the presence of plasma lipoproteins raises questions about their stability and subsequent interaction with LCAT. 相似文献
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Alina Iulia Chiriac Edith Marleny Cadena Teresa Vidal Antonio L. Torres Pilar Diaz F. I. Javier Pastor 《Applied microbiology and biotechnology》2010,86(4):1125-1134
Cel9B from Paenibacillus barcinonensis is a modular endoglucanase with a novel molecular architecture among family 9 enzymes that comprises a catalytic domain (GH9),
a family 3c cellulose-binding domain (CBM3c), a fibronectin III-like domain repeat (Fn31,2), and a C-terminal family 3b cellulose-binding domain (CBM3b). A series of truncated derivatives of endoglucanase Cel9B have
been constructed and characterized. Deletion of CBM3c produced a notable reduction in hydrolytic activity, while it did not
affect the cellulose-binding properties as CBM3c did not show the ability to bind to cellulose. On the contrary, CBM3b exhibited
binding to cellulose. The truncated forms devoid of CBM3b lost cellulose-binding ability and showed a reduced activity on
crystalline cellulose, although activity on amorphous celluloses was not affected. Endoglucanase Cel9B produced only a small
ratio of insoluble products from filter paper, while most of the reducing ends produced by the enzyme were released as soluble
sugars (91%), indicating that it is a processive enzyme. Processivity of Cel9B resides in traits contained in the tandem of
domains GH9–CBM3c, although the slightly reduced processivity of truncated form GH9–CBM3c suggests a minor contribution of
domains Fn31,2 or CBM3b, not contained in it, on processivity of endoglucanase Cel9B. 相似文献
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Iancu IV Botezatu A Goia-Ruşanu CD Stănescu A Huică I Nistor E Anton G Pleşa A 《Roumanian archives of microbiology and immunology》2010,69(3):113-118
Human papillomaviruses (HPV) are considered the etiological agents of cervical cancer, especially high-risk genotypes. TGF-beta (transforming growth factor-beta) is well known for its anti-proliferative effects but the neoplastic cells often lose their sensitivity to TGF-beta. A characteristic alteration associated with malignant progression is the loss of responsiveness to TGF-beta1-induced cell growth inhibition. The aim of the present study was to establish the possible role of some members of TGF-beta signalling pathway during cervical cancer development and the possible relationship with HPV infection. In order to establish TGF-beta gene expression levels in cervical oncogenesis, TGF-beta1, TGF-beta1 receptors and Smad2 were investigated in precancerous and cervical cancer samples (Quantitative Real-Time PCR). The study revealed that 84.5% of patients were positive for HPV DNA. The most prevalent HPV genotypes were high-risk HPV 16 and 18 in single or co-infections. Expression of TGF-beta1 decreased as tumor cells progressed from cervical intraepithelial neoplasia to cervical carcinoma. Furthermore, we observed that cervical lesions without HPV infection expressed significantly less TGF-beta1. TGF-betaRI and Smad2 gene expression levels were found to be decreased in SCC and AC samples in contrast with CIN1 and CIN2/3 samples. Our results showed that in human cervical cancer the disruption of TGF-beta/Smad signalling pathway might contribute to the malignant progression of cervical dysplasia. These data emphasize the importance of canonical TGF-beta pathway integrity in carcinogenesis. 相似文献
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Marko T. Ahonen Iulia Diaconu Sari Pesonen Anna Kanerva Marc Baumann Suvi T. Parviainen Brad Spiller Vincenzo Cerullo Akseli Hemminki 《PloS one》2010,5(9)
Background
Adenoviruses are attractive vectors for gene therapy because of their stability in vivo and the possibility of production at high titers. Despite exciting preclinical data with various approaches, there are only a few examples of clear efficacy in clinical trials. Effective gene delivery to target cells remains the key variable determining efficacy and thus enhanced transduction methods are important.Methods/Results
We found that heated serum could enhance adenovirus 5 mediated gene delivery up to twentyfold. A new protein-level interaction was found between fiber knob and serum transthyretin, but this was not responsible for the observed effect. Instead, we found that heating caused the calcium and phosphate present in the serum mix to precipitate, and this was responsible for enhanced gene delivery. This finding could have relevance for designing preclinical experiments with adenoviruses, since calcium and phosphate are present in many solutions. To translate this into an approach potentially testable in patients, we used calcium gluconate in phosphate buffered saline, both of which are clinically approved, to increase adenoviral gene transfer up to 300-fold in vitro. Gene transfer was increased with or without heating and in a manner independent from the coxsackie-adenovirus receptor. In vivo, in mouse studies, gene delivery was increased 2-, 110-, 12- and 13-fold to tumors, lungs, heart and liver and did not result in increased pro-inflammatory cytokine induction. Antitumor efficacy of a replication competent virus was also increased significantly.Conclusion
In summary, adenoviral gene transfer and antitumor efficacy can be enhanced by calcium gluconate in phosphate buffered saline. 相似文献28.
The objectives of this study were to determine if heme oxygenase (HO), which catalyzes the degradation of heme and the formation of carbon monoxide (CO), is localized in the rat anterior pituitary and, if so, to determine if hemin (a substrate for HO) or chromium mesoporphyrin (CrMP) (an inhibitor of HO), alter pituitary gonadotropin and prolactin secretion. For localization of HO, sections of anterior pituitaries obtained from mature Holtzman Sprague-Dawley rats in different stages of the estrous cycle were immunostained for two of the HO isoforms, HO-1 and HO-2. The immunostaining for the inducible HO isoform (HO-1) was limited to discrete populations of pituitary cells, whereas the constitutive isoform (HO-2) had a more widespread distribution. The afternoon surge of leutinizing hormone (LH) in the plasma of ovariectomized, estradiol-treated rats was advanced by 2 hr after 7 days of treatment with CrMP (4 micro M/kg), and this effect was reversed when hemin (30 micro M/kg) was co-administered with CrMP. The afternoon follicle-stimulating hormone (FSH) surge was not affected by either treatment. In contrast, the afternoon prolactin (PRL) surge was completely blocked or delayed by CrMP treatment, and this effect was not reversed by hemin. In vitro perifusion of pituitary explants with CrMP also significantly reduced PRL release compared with secretion from untreated explants. In vitro gonadotropin-releasing hormone (GnRH)-stimulated FSH secretion was significantly increased from pituitary explants of ovariectomized, estradiol-treated rats treated in vivo with hemin but was unaffected by CrMP treatment, whereas GnRH-stimulated LH release was not affected by hemin but was increased by CrMP treatment. In conclusion, this study demonstrates that HO exists in the rat anterior pituitary gland, and that a substrate and an inhibitor of this enzyme alter the secretion of gonadotropins and PRL. 相似文献
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Uranium distributions and contents inMysidacea species were investigated in order to be subsequently correlated with some specific properties of these crustacea. The fission
track micromapping technique was used in uranium distribution and content measurements. The investigated biological samples
were: (1)Javanisomysis gutzui Bacescu, 1992 and (2)Mesopodopsis slabberi Van Beneden, 1861. The determined contents varied in the range of natural background values of uranium. 相似文献
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Ioanitescu AI Dewilde S Kiger L Marden MC Moens L Van Doorslaer S 《Biophysical journal》2005,89(4):2628-2639
The nonsymbiotic tomato hemoglobin SOLly GLB1 (Solanum lycopersicon) is shown to form a homodimer of approximately 36 kDa with a high affinity for oxygen. Furthermore, our combined ultraviolet/visible, resonance Raman, and continuous wave electron paramagnetic resonance (EPR) measurements reveal that a mixture of penta- and hexacoordination of the heme iron is found in the deoxy ferrous form, whereas the ferric form shows predominantly a bis-histidine ligation (F8His-Fe(2+/3+)-E7His). This differs from the known forms of vertebrate hemoglobins and myoglobins. We have successfully applied our recently designed pulsed-EPR strategy to study the low-spin ferric form of tomato hemoglobin. These experiments reveal that, in ferric SOLly GLB1, one of the histidine planes is rotated 20 degrees (+/-10 degrees ) away from a N(heme)-Fe-N(heme) axis. Additionally, the observed g-values indicate a quasicoplanarity of the histidine ligands. From the HYSCORE (hyperfine sublevel correlation) measurements, the hyperfine and nuclear quadrupole couplings of the heme and histidine nitrogens are identified and compared with known EPR/ENDOR data of vertebrate Hbs and cytochromes. Finally, the ligand binding kinetics, which also indicate that the ferrous tomato Hb is only partially hexacoordinated, will be discussed in relation with the heme-pocket structure. The similarities and differences with other known nonsymbiotic plant hemoglobins will be highlighted. 相似文献