Isoflavonoids isolated from Cuban propolis   总被引：3，自引：0，他引：3  

Piccinelli AL  Campo Fernandez M  Cuesta-Rubio O  Márquez Hernández I  De Simone F  Rastrelli L 《Journal of agricultural and food chemistry》2005,53(23):9010-9016

Chemical investigation of a red-type Cuban propolis sample has led to the isolation of 11 isoflavonoids (2 isoflavones, 3 isoflavans, and 6 pterocarpans), together with gallic acid, isoliquiritigenin, and (-)-liquiritigenin. Structural determination, including the absolute stereochemistry, was accomplished by spectroscopic analysis, particularly CD and 2D NMR techniques. The fragmentation behavior of pterocarpans was studied by electrospray ionization (ESI) tandem mass spectrometry (MS/MS) using an ion-trap analyzer, and a generalized fragmentation pathway, useful in the identification and structural characterization of pterocarpans, is proposed. Isoflavonoids are reported for the first time from propolis samples.  相似文献   

Forms of trace metals from inorganic sources in soils and amounts found in spring barley     

Anna Chlopecka 《Water, air, and soil pollution》1993,69(1-2):127-134

Barley (Hordeum vulgare L.) was grown on a sandy soil given different doses of cadmium carbonate (salt), copper carbonate (malachite), lead carbonate (cerussite), and zinc carbonate (smithsonite) in a pot experiment conducted in a greenhouse. The element compounds were added to the soil in amounts equivalent to the following levels of the metals: Cd 5, 10, 50 μq ^?1; Cu and Pb 50, 100, 500 μg g^?1; Zn 150, 300, 1500 μg g^?1. Sequential extraction was used for partition these metals into five operationally-defined fractions: exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and residual. The residue was the most abundant fraction in the untreated soil for all the metals studied (43 to 61% of the total contents). The concentration of exchangeable Cd (0.2 μg g^?1), Cu (0.01 μg g^?1), Pb (0.1 μg g^?1), and Zn (1.4 μg g^?1) were relatively low in the untreated soil but increased markedly in the treated soils for Cd (up to 31 μg g^?1) and Zn (up to 83 μg g^?1), whereas only small changes were observed for Cu and Pb. The pot experiment showed a significant increase in the Cd and Zn contents of barley grown on the treated soils, but only small changes in Cu and Pb concentrations.  相似文献   

Discrimination of intact and injured Listeria monocytogenes by Fourier transform infrared spectroscopy and principal component analysis     

Lin M  Al-Holy M  Al-Qadiri H  Kang DH  Cavinato AG  Huang Y  Rasco BA 《Journal of agricultural and food chemistry》2004,52(19):5769-5772

Fourier transform infrared spectroscopy (FT-IR, 4000-600 cm(-)(1)) was used to discriminate between intact and sonication-injured Listeria monocytogenes ATCC 19114 and to distinguish this strain from other selected Listeria strains (L. innocua ATCC 51742, L. innocua ATCC 33090, and L. monocytogenes ATCC 7644). FT-IR vibrational overtone and combination bands from mid-IR active components of intact and injured bacterial cells produced distinctive "fingerprints" at wavenumbers between 1500 and 800 cm(-)(1). Spectral data were analyzed by principal component analysis. Clear segregations of different intact and injured strains of Listeria were observed, suggesting that FT-IR can detect biochemical differences between intact and injured bacterial cells. This technique may provide a tool for the rapid assessment of cell viability and thereby the control of foodborne pathogens.  相似文献   

Predictors of pregnancy and postpartum haemoglobin concentrations in low-income women   总被引：1，自引：0，他引：1  

Bodnar LM  Siega-Riz AM  Arab L  Chantala K  McDonald T 《Public health nutrition》2004,7(6):701-711

OBJECTIVE: Pregnancy and postpartum iron status is of great public health importance, yet few studies have examined predictors of haemoglobin (Hb) concentration during this time. We identified predictors of Hb from 24 weeks' gestation until delivery and from 4 to 25 weeks postpartum. DESIGN: Blood was drawn as many as four times during care: at the initial visit, at 24-29 weeks' gestation, at delivery and postpartum. A longitudinal, multivariable linear regression model was used to predict Hb concentration. SETTING: A public health clinic in Raleigh, North Carolina.Subjects: n=520 women who participated in the Iron Supplementation Study. RESULTS: Hb concentration at the previous blood draw, short stature, non-Hispanic white ethnicity/race, >12 years of education and smoking were positive predictors of pregnancy and postpartum Hb concentrations. Iron supplement use was a positive predictor, while inadequate weight gain and severe nausea/vomiting were negative predictors of gestational Hb. A high infant birth weight and postpartum haemorrhage were negative predictors of postpartum Hb. Pre-pregnancy body mass index had a slight positive relationship with gestational Hb, but had a strong negative relationship with postpartum Hb. The longitudinal model also confirmed the typical pattern of gestational Hb concentration. As the number of weeks between the initial visit and the 24- to 29-week visit increased, Hb at 24-29 weeks' gestation decreased. As gestational age increased from 24 weeks until delivery, Hb concentration increased as well. CONCLUSIONS: The predictors identified here could be used in clinical settings to target high-risk women for intervention.  相似文献   

ADP ribosylation factor regulates metabolism and antioxidant capacity of transgenic potato tubers     

Zuk M  Prescha A  Kepczyński J  Szopa J 《Journal of agricultural and food chemistry》2003,51(1):288-294

In our recent studies we have evidenced that repression of ADP-ribosylation factor (ARF) in potato plants results in 14-3-3 gene activation. The significant alteration in plant phenotype and in carbohydrate content clearly indicates that there may also be changes in other metabolite syntheses. In this paper we present the data on contents of compounds, occurring in transgenic potato tubers from field trial, known to be important for the human diet. We also determine which of the ARF-antisense plant features resulted from ARF repression. This determination was accomplished by the analysis of ARF-antisense plants transformed with cDNA encoding 14-3-3 protein in reverse orientation. The sucrose accumulation and the decrease in glycoalkaloids level were found to be characteristic features of all transgenic plants. The increase in antioxidant capacity of transgenic potato tubers should also be pointed out. The analysis of fat from modified potato tubers revealed a nutritionally valuable composition of fatty acids, including the significant increase of linoleic acid level.  相似文献   

Microbial 16S gene-based composition of a sorghum cropped rhizosphere soil under different fertilization managements     

Anna Lavecchia  Maddalena Curci  Kamlesh Jangid  William B. Whitman  Patrizia Ricciuti  Silvia Pascazio  Carmine Crecchio 《Biology and Fertility of Soils》2015,51(6):661-672

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Effects of accelerated pollen-cone development on pollen cytology and fertilizing potential in western hemlock (Tsuga heterophylla)     

Anna M. Colangeli  John N. Owens 《Forest Ecology and Management》1991,40(3-4):151-162

Western hemlock (Tsuga heterophylla (Raf). Sarg.) pollen cones on cut branches were collected at different stages of development and maintained at room temperature in flasks of water to accelerate pollen-cone development and produce forced pollen. Accelerating pollen-cone development at early developmental stages reduced the number of cones that matured, decreased the quantity of pollen produced, increased the proportion of abnormally developed pollen and reduced the fertilizing potential of the pollen, as determined by seed efficiency. If the branches were collected after the pollen cones were at least 50% emerged beyond the bud scales, pollen-cone development could be successfully accelerated without decreasing pollen yield or fertilizing potential. Pollen collected from cones which were accelerated at early stages and stored for two years had a lower fertilizing potential and produced fewer seeds per cone than either unstored pollen or stored pollen collected from cones accelerated at later stages of development. The feasibility of accelerating pollen-cone development to ensure adequate supplies of pollen for controlled crosses or supplemental mass pollination is discussed.  相似文献   

Ultrastructure of theca interna cells of porcine ovarian follicle.     

Anna Krzysztofowicz  Stanislawa Stoklosowa 《Anatomia, histologia, embryologia》1977,6(4):359-364

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Treatment of citrus fruit with sodium o-phenylphenate foam     

Anna Rajzman  A. Apelbaum 《Pest management science》1970,1(2):59-62

The treatment conditions for reducing the incidence of rot in stored citrus fruit with sodium o-phenylphenate (SOPP) foam and the possibility of improving the efficiency of the treatment were examined. Marked differences were noted among different packing houses with regard to ambient temperature temperature of the fruit surface, duration of treatment, SOPP content and pH of the solution, quantities of foam and of SOPP dispersed on the fruit, and between the o-phenylphenol (OPP) residues in fruit treated simultaneously. It should be possible to prolong the duration of treatment without increasing the OPP residues in the fruit above the tolerance limits of 10 ppm OPP in the whole fruit and without causing injury to the fruit.  相似文献   

Clostridium perfringens toxin-types in lambs and kids affected with gastroenteric pathologies in Italy     

Greco G  Madio A  Buonavoglia D  Totaro M  Corrente M  Martella V  Buonavoglia C 《Veterinary journal (London, England : 1997)》2005,170(3):65-350

A study was carried out in the South of Italy to assess the role of clostridia in neonatal diseases of lambs and kids. Eighty-seven lambs and 15 kids belonging to 25 flocks were examined and Clostridium perfringens was the microorganism most commonly identified. C. perfringens isolates were analysed by polymerase chain reaction (PCR), in order to determine the prevalence of the genes cpa, cpb, cpb2, etx, iap and cpe. The most prevalent toxin-type of C. perfringens was found to be type A found in 84% of the cases with clostridial enterotoxaemia. No C. perfringens type B, C or E were found. C. perfringens type D was isolated in 16% of the cases. About 24% of the isolates were cpb2 positive. The prevalence of cpb2 across the different C. perfringens types varied. The beta(2)-toxin gene cpb2 was detected in 4/21 (19%) type A isolates, in 1/2 type D isolates, and in 1/2 type DE (cpe-carrying type D) isolates. The high rate of positivity to cpb2 among the isolates suggests that a vaccine based on the beta(2)-toxin, should be included in the vaccination schedule of the animals to confer adequate protection and to prevent the disease.  相似文献