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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Mitigation of condensed tannins found in sericea lespedeza (Lespedza cuneata)

Eckerle, Gregory J. January 1900 (has links)
Doctor of Philosophy / Department of Animal Sciences and Industry / K.C. Olson / Sericea lespedeza (SL; Lespedeza cuneata) is classified as an invasive plant throughout the Great Plains. It infests over 600,000 acres in Kansas. Increasing grazing pressure on SL may reduce seed production and slow the spread of the plant; however, intake of SL by grazing beef cattle is poor, due to the presence of tannins in the plant. Condensed tannins reduce protein digestion by ruminants and may also decrease plant palatability. Detailed study of the appetite-suppressing effects of SL under controlled conditions is essential in order to develop appropriate strategies to increase grazing pressure on this plant. Such information could lead to a degree of biological control of this noxious weed using domestic herbivores. We compared intakes of tallgrass prairie hay by beef cows when hay was either uncontaminated or heavily contaminated by SL. Beef cows fed contaminated hay exhibited a profound aversion to compared to similar uncontaminated hay. Furthermore, differences in voluntary DMI between contaminated and uncontaminated hays of similar chemical composition were manifested rapidly after introduction of contaminated hay into beef cow diets. Supplementation with corn steep liquor (CSL) increased tolerance of beef cows for SL. It ameliorated the negative consequences of tannin consumption in a dose-dependent manner when fed to beef cows in confinement. The beef cows in our study had only limited opportunity to selectively avoid SL because it was offered in chopped form and in a mixture with other forage species. It was unknown if beef cattle supplemented with CSL would readily consume forage contaminated by SL when uncontaminated forage was available simultaneously. Therefore, we examined the effects of CSL fed to beef cows on voluntary selection of tallgrass prairie hay contaminated by SL when uncontaminated tallgrass prairie hay was also available. Supplemental CSL (0.6 kg DM/d) increased both acceptance of and tolerance for SL by beef cows. It ameliorated some of the negative consequences of tannin consumption on digestible DM intake. In addition, voluntary consumption of SL-contaminated forage increased by 25% in supplemented vs. unsupplemented beef cows. It is unknown if supplemental CSL can promote voluntary selection of actively-growing SL by beef cattle grazing native rangeland in the Kansas Flint Hills.
2

Antidiabetic activity of pentacyclic triterpenes and flavonoids isolated from stem bark of Terminalia sericea Burch.Ex DC

Nkobole, Nolitha Khanya 21 October 2009 (has links)
Diabetes mellitus (DM) represents a series of metabolic conditions associated with hyperglycemia and caused by defects in insulin secretion, and/ insulin action. Exposure to chronic hyperglycemia may result in microvascular complications in the retina, kidney or peripheral nerves. According to the World Health Organization (WHO) global burden of disease, more than 176 million people are diabetic with about two thirds of these living in developing countries. With a long course and serious complications that often result in high incidences of mobility and mortality rate, the treatment of diabetes is often costly. The management of this disease is not without side effects and this is a challenge to the medical system. This has led the researches to seek new antidiabetic agents from plants. Acetone extract of 8 plants namely Terminalia sericea Burch. Ex DC, Euclea natalensis A.DC, Warbugia salutaris Bertol.f.) Chiov., Artemisia afra Jacq.ex Willd., Aloe ferox Mill, Sclerocarya birrea (A.Richi.) Hochst. subsp. caffra , Spirostachys Africana Sond and Psidium guajava L were evaluated for antidiabetic and antioxidant properties. In addition extracts were tested for cytotoxicity. Different parts of all these plants are traditionally used in South Africa for diabetes treatment. Plants were selected based on ethnobotanical information and phytochemical constituents. For determining inhibitory activity against each enzyme (α-glucosidase and α- amylase), all extracts were tested at concentration that ranged from 2x10-5 to 0.2mg/ml for α-glucosidase and 0.025 to 1.25mg/ml for α-amylase and fifty percent inhibition or higher was taken as significant (p<0.05). The extracts of A. ferox and S. africana showed no inhibition against α-glucosidase at the highest concentration tested (0.2mg/ml) whereas A. afra showed weak inhibition (47.15%). T. sericea showed to be a potent inhibitor of α-glucosidase exhibiting 97.44 % inhibition of the enzyme (p<0.05). W. salutaris, S birrea and E. natalensis also showed good activity on α-glucosidase as they demonstrated 71.84; 97.44 and 92.60 % inhibition respectively (p<0.05). Other plant extracts such as A. ferox and S. africana did not exhibit any activity on α-glucosidase. T. sericea and S. birrea showed the best inhibitory activity on α-amylase enzyme, exhibiting 91.91 and 94.94 % inhibition respectively at 1.25mg/ml. A. afra, E. natalensis, P. guajava and W. salutaris also showed good inhibitory activity on -amylase enzyme at 1.25mg/ml which was the highest concentration tested (p<0.05). Low levels of plasma antioxidants is a risk factor associated with diabetes therefore, it has been suggested that plant-based medicines that contain antioxidant properties add an advantage in curbing complications that arise during DM aetiology. The antioxidant activity of plant extracts was carried out using 2, 2-Diphenyl-1-Picrylhydrazyl (DPPH) assay. Six plant extracts which showed good α-glucosidase and α-amylase inhibitory activity were evaluated for antioxidant activity. The radical scavenging activity was measured in terms of the amount of antioxidants necessary to decrease the initial DPPH absorbance (EC50). The EC50 is the amount of antioxidants necessary to decrease initial DPPH absorbance by 50%. All 6 tested plant extracts showed good activity. W. salutaris and T. sericea demonstrated the highest activity exhibiting EC50 values of 5.08 and 5.56βg/ml respectively as compared to ascorbic acid/Vitamin C (EC50=2.52μg/ml), a well- known potent antioxidant. This was followed by P. guajava (EC50=6.97μg/ml); E. natalensis (EC50=8.46μg/ml) and S. birrea (EC50=9.41μg/ml). A. ferox showed EC50 value of 48.53μg/ml. It has been suggested that plant extracts and compounds must undergo toxicity test for safety before drug discovery is taken into consideration. Due to the large number of plants screened in this study and limited resources in our laboratory, only the acetone extract of T. sericea (which demonstrated good α-glucosidase and -amylase inhibitory activities) was tested for cytotoxicity. Acetone extract of T. sericea demonstrated moderate toxicity against primary vervet monkey kidney cells (VK) cells exhibiting IC50 values of 20.94 μg/ml when tested at 400μg/ml. Consequently, the acetone extract of T. sericea was selected for the isolation and identification of bioactive compounds. A bio-assay guided fractionation of the acetone extract of T. sericea led to the isolation of 4 pure compounds namely β-sitosterol, β-sitosterol-3-acetate, lupeol and 3-onestigmasterol and two sets of mixtures of isomers (epicatechin-catechin; MI1 and epigallocatechingallocatechin; MI2). Antidiabetic, antioxidant and cytotoxicity activities of isolated compounds were evaluated. μ–Sitosterol and lupeol showed best inhibitory activity on α-glucosidase exhibiting 50% inhibitory concentration (IC50) value of 54.50 μM and 66.48 μM respectively (p<0.05). This was followed by the MI2; epigallocatechin-gallocatechin (IC50=119.34 μM); β-sitosterol-3-acetate (IC50=129.34 μM); 3-one-stigmasterol (IC50=164.87 μM) and the MI1; epicatechin-catechin (IC50=255.76 μM). During the evaluation of purified compound’s inhibitory activity on α-amylase, compounds of interest were lupeol and β-sitosterol which exhibited IC50 values of 140.72 μM and 216.02 μM respectively as compared to the positive drug-control acarbose (IC50=65.25 μM). Epicatechincatechin and epigallocatechin-gallocatechin also demonstrated α-amylase inhibitory properties and the IC50 values were found to be lower than 100μg/ml. Epigallocatechin-gallocatechin, epicatechin-catechin and lupeol showed good free radical scavenging activity as they inhibited DPPH by 98.19; 96.98 and 70.90 % at 100ìg/ml respectively (p<0.05). The DPPH scavenging activity was very low in case of 3-one-stigmasterol (21.5% inhibition), whilst β-sitosterol and its derivative β-sitosterol-3-acetate did not show any activity. During cytotoxicity evaluation of pure compounds against monkey kidney cells, all the compounds except β-sitosterol did not inhibit the growth of these cells lines at the highest concentration tested (200μg/ml). β-Sitosterol showed moderate toxicity exhibiting IC50 values of 197.72 μM. β- Sitosterol-3-acetate, epicatechin-catechin, lupeol and epigallocatechin-gallocatechin were found to be non-toxic to Vero cells as 100% cell viability was observed when Vero cells were exposed to these samples at 200μg/ml. The compounds isolated and the extract of T. sericea demonstrated significant antidiabetic and antioxidant properties as compared to well known drugs acarbose (a known -glucosidase and α- amylase inhibitor) and Vitamin C (a well known antioxidant). This study is the first to report α- glucosidase, α-amylase and antioxidant properties of epicatechin-catechin, epigallocatechingallocatechin, β-sitosterol-3-acetate and stigma-4-ene-3-one isolated from T. sericea. In addition, epicatechin-catechin, epigallocatechin-gallocatechin, β-sitosterol-3-acetate and stigma-4-ene-3-one are isolated from T. sericea for the first time. Overall all results scientifically validated the traditional use of the bark of T. sericea for diabetes in South Africa. / Dissertation (MSc)--University of Pretoria, 2011. / Plant Science / unrestricted
3

Replacing sunflower oilcake with Sericea lespedezaand/or urea on feed digestibility and milk production of Saanen goats

Malate, Andries January 2017 (has links)
In conditions where supplementation of poor quality diets is a major challenge, forage legumes such as Sericea lespedeza can be a good alternative supplement for protein at lower cost than most commercial concentrates. From studies done on Sericea lespedeza it is found plausible and valuable to supplement urea with Sericea lespedeza to strategically combat the deleterious effect of condensed tannins in the Sericea lespedeza and provide nitrogen in the rumen. This study was aimed to evaluate the effect of replacing sunflower oilcake with urea (a rumen degradable protein RDP source) or Sericea lespedeza (rumen undegradable protein RUP source) mixed with urea as nitrogen/protein sources on nutrient utilization, milk yield and milk composition of Saanen dairy goats. A digestibility and lactation study were conducted at the University of Pretoria Research Farm and chemical analysis performed at the University Nutrilab. A 30 days digestibility study was conducted on male Saanen goats after the lactation study, with 23 days adaptation and 7 days data collection period. Nine male goats were randomised and allocated to the three treatments in metabolism cages. In the lactation study 36 dairy goats were blocked according to milk collected on first month of lactation into high, medium and low milk yielders, then allocated to the three treatments of total mixed rations containing sunflower oilcake (T1) at 7% main protein source, T2 (urea at 1%) and T3- Sericea lespedeza at 12.5% mixed with urea according to a complete randomised block design (CRBD). Milk samples were collected from individual goats monthly at two consecutive milking’s. The samples were analysed for milk fat, protein, lactose, somatic cell count and milk urea nitrogen using a Milko-Scan analyser (at Irene Lacto lab). In the digestibility study, dry matter intake was significantly higher for goats fed on Sericea lespedeza with urea (T3) diet than goats fed on T1 and T2 diet. Goats on T3 diet had also significantly higher organic matter and crude protein intake than those goats fed on the other two TMR diets. The results also shows that the mean daily milk yields for the goats in the T1, T2 and T3 were 2.56, 2.46 and 2.52 kg per day respectively. T2 group had higher milk fat % (3.61) and higher milk urea nitrogen (MUN - 25.70 mg N/dl) than the other two treatments. T1 had significantly higher milk protein %. There was a great difference in milk composition of the afternoon milk as compared to the morning milk. The three TMRs had no significant difference in the nitrogen utilization and nitrogen excretion. It is then concluded that Sericea lespedeza mixed with urea can be used as subsititutes for sunflower oilcake in the diets of dairy goats since no negetive effect was found. However further investigations are needed. / Dissertation (MSc Agric)--University of Pretoria, 2017. / DAAD-NRF / International Foundation for Science (IFS) / Animal and Wildlife Sciences / MSc (Agric) / Unrestricted
4

Responses of grassland birds and butterflies to control of sericea lespedeza with fire and grazing

Ogden, Sarah B. January 1900 (has links)
Master of Science / Division of Biology / David A. Haukos / Sericea lespedeza (Lespedeza cuneata) is an invasive forb that reduces native grass and forb abundance in tall-grass prairie by up to 92%. Controlling invasions is difficult because traditional land management tools used in the Flint Hills, broad spectrum herbicides, spring prescribed fire, and cattle grazing, are ineffective against sericea. Recent research has demonstrated, however, that mid- and late summer prescribed fire and spring fire with early season grazing by steers followed by late season grazing by sheep are effective at reducing sericea whole plant mass, number of seeds produced, and seed mass. Field results were from two separate experiments conducted in tall-grass prairie study sites in the Flint Hills. On a Geary County, Kansas, study site, the utility of 1) spring fire (control), 2) mid-summer fire, and 3) late summer fire on sericea control were compared. On a Woodson County, Kansas, study site, the utility of 1) spring fire with early season steer grazing followed by rest (control) and 2) spring fire with early season steer grazing and late season sheep grazing on sericea control were compared. At the same study sites, I measured responses by the native wildlife community to use of summer fire and sheep grazing, relative to their controls, to manage sericea lespedeza. Specifically, my objectives were to compare grassland songbird density, grassland songbird nest survival, and grassland butterfly species composition and density among treatments at both study sites. I also related patterns in the vegetation community of each treatment for each study site to respective patterns in grassland bird and butterfly communities. Within study sites, density, nest density, and nest success of grassland bird communities responded similarly to treatments and controls, with the exception that densities of Grasshopper Sparrows (Ammodramus savanarrum) were 3.4- and 2.2-fold greater in mid- and late summer fire plots than spring fire plots, respectively, in the Geary County study site. Species compositions of butterfly communities were similar across treatments within experiments, but grassland specialist species comprised only 8.6 and 1.2% of all butterfly observations in the Geary County and Woodson County experiments, respectively. Grassland specialist butterfly species may benefit from summer fire, as their nectar sources were more abundant in Summer Fire plots than Spring Fire plots. Overall, within each experiment, grassland bird and butterfly communities were similar across treatments, suggesting that treatments did not negatively affect grassland songbird and butterfly communities. I additionally demonstrated that Dickcissel (Spiza americana) nest sites contain a lower proportion of sericea than random points, the first evidence that the invasion is detrimental to grassland songbird species. Lacking control, the continued sericea invasion will out compete cumulatively more forb plants resulting in declining quality of grassland bird nesting habitat on the landscape. Controlling sericea lespedeza invasions will allow native forb species to increase in abundance and improve the condition of grasslands for native wildlife and livestock producers. Therefore, I advocate use of summer fire or spring fire with a combination of cattle and sheep grazing to control sericea lespedeza with the long-term goal of tall-grass prairie restoration.
5

Assessing the potential of mixed grazing goats with beef cattle to improve animal performance and increase the utilization of marginal pasturelands in the Appalachian coal region

Webb, Darryl Matthew 26 May 2008 (has links)
Reclaimed coal-mined lands in the Appalachian region can be successful established and utilized for beef cattle production. Currently, these areas are underutilized partly due to an increase in invasive plant species, such as multiflora rose (Rosa multiflora Thunb. Ex Murr.), autumn olive (Elaeagnus umbellata Thunb.), and sericea lespedeza (Lespedeza cuneata (Dum.-Cours.) G. Don). The steep topography and low economic returns from beef cattle make conventional control methods inhibitive. Goats are effective browsing on invasive plant species. An experiment was conducted in 2006 and 2007 at the Powell River Research and Education Center near Wise, VA (77° 43' 30" west longitude, 38° 57' 30" north latitude, elevation 155.5 m) to determine the effects of an ungrazed control, cattle alone grazing, and mixed grazing goats with cattle on forage biomass, botanical composition, relative plant abundance, and animal performance. The three treatments included an ungrazed control, cattle grazing alone, and mixed grazing goats with cattle. Experimental design was a randomized complete block design with two replicates for the control and three replicates for the grazed treatments. Three times during the grazing season the following were measured, analyzed or assessed: nutritive values of pasture, autumn olive, multiflora rose, and sericea lespedeza were assessed; forage biomass was determined by clipping four 0.25 m² quadrants per control replicate and eight 0.25 m² quadrants per grazed replicate; botanical composition and relative abundance of plant species was assessed by the Double DAFOR method from five fixed points in each control replicate and ten fixed points in each grazed replicate; animals were weighed; autumn olive shrub height was measured with a clinometer from a distance of 10 m from the shrub. Branch length was measured with a tape measure from the base of the branch to the end tip. Shrub survival was measured by counting shrubs in each replicate and determining visually percent leaf-out. Each year, control and cattle alone treatments had greater (P < 0.05). Generally, grass content increased in the grazed treatments from spring to fall while weed content increased in the control treatment (P < 0.05). By the end of the two experimental years, the legume components of the pasture were low. This was more evident in the ungrazed control than the grazed treatments. The relative abundance of tall fescue and orchardgrass (P < 0.05) increased in grazed treatments while sericea lespedeza became a dominant weed in the control (P < 0.05). Goats showed high preference for sericea lespedeza and maintain this plant in a leafy, vegetative stage. This leafy, vegetative growth was found to acceptable to cattle. Cattle performance was not affected by treatment (P < 0.05) but total animal output was higher for mixed grazed compared to cattle alone treatments (P < 0.05). The nutritive values of multiflora rose, autumn olive, and sericea lespedeza were higher than pasture in most instances (P < 0.05). In our experiment, autumn olive was severely impacted by goat browsing. Shrub survival was lower in mixed grazing (61%) by the end of the experiment compared to over 90% for the control and cattle grazing treatments (P < 0.05). Overall, pastures were utilized more uniformly in mixed grazing compared to other treatments. Mixed grazing goats with cattle appear to be a viable option for livestock producers in the Appalachian coal mining region. / Master of Science
6

AVALIAÃÃO DO POTENCIAL ANTIMICROBIANO DO EXTRATO ETANÃLICO E FRAÃÃES OBTIDAS DE Guettarda sericea MÃll. Arg.(RUBIACEAE) / EVALUATION OF ANTIMICROBIAL POTENTIAL ETHANOLIC EXTRACT AND FRACTIONS OBTAINED FROM Guettarda sericea MÃll. Arg. (RUBIACEAE)

Ãrica de Menezes Rabelo 26 April 2013 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O gÃnero Guettarda (Rubiaceae) compreende plantas extensamente distribuÃdas em Ãreas tropicais. Com relaÃÃo à espÃcie Guettarda sericea, a literatura demonstra que existe uma ampla carÃncia acerca de estudos botÃnicos e fitoquÃmicos. Assim, o presente trabalho buscou avaliar o efeito antibacteriano do extrato etanÃlico das folhas de G. sericea (EEFGS) e suas fraÃÃes sobre o crescimento de Streptococcus oralis ATCC 10557 e S. salivarius ATCC 7073, nas formas planctÃnicas e de biofilmes. Diferentes metodologias foram empregadas para a verificaÃÃo do potencial antimicrobiano. Dentre estas estÃo a determinaÃÃo da concentraÃÃo inibitÃria mÃnima (MIC), a determinaÃÃo da curva de morte e a avaliaÃÃo da concentraÃÃo bactericida mÃnima (MBC). AlÃm disso, a quantificaÃÃo da biomassa e do nÃmero de cÃlulas viÃveis do biofilme foi realizada, respectivamente, atravÃs da coloraÃÃo pelo cristal violeta e contagem de unidades formadoras de colÃnia (UFC). Os controles, negativo e positivo utilizados em todos os ensaios foram, respectivamente, DMSO 4% e Gluconato de Clorexidina com concentraÃÃo ajustada de acordo com os dados da CIM de cada micro-organismo. Para a determinaÃÃo da toxicidade do EEFGS utilizou-se o ensaio de toxicidade sobre nÃuplios de Artemia. Os dados mostraram que o extrato e as subfraÃÃes 13 a 17 da fraÃÃo clorofÃrmio apresentaram um marcante efeito antimicrobiano, sendo capazes de inibir o crescimento planctÃnico, bem como o desenvolvimento de biofilmes da cepa de S. oralis atà a concentraÃÃo de 62,5 Âg.mL-1. Com relaÃÃo a S. salivarius, apenas a subfraÃÃo 12 interferiu sobre o crescimento bacteriano. No tocante à toxicidade, foi observado que a morte dos nÃuplios de Artemia ocorreu em concentraÃÃes mais elevadas do que aquelas que apresentaram efeito antibacteriano. A partir de tais resultados pode-se concluir que EEFGS e as subfraÃÃes 13 a 17 podem ser utilizados como insumos para o controle da formaÃÃo de biofilmes de S. oralis. Em adiÃÃo, metodologias complementares que busquem a purificaÃÃo dos compostos ativos e seus efeitos citotÃxicos sobre cÃlulas eucariÃticas necessitam ser realizadas, visando sua utilizaÃÃo como um agente fitoterÃpico. / The genus Guettarda (Rubiaceae) comprises plants widely distributed in tropical areas. Regarding the Guettarda sericea species, the literature shows that there is a lack of botanical and phytochemicals studies. Thus, the present study aimed to evaluate the antibacterial effect of ethanol extract of leaves of G. sericea (EEFGS) and its fractions on the growth of Streptococcus oralis ATCC 10557 and S. salivarius ATCC 7073 in both the planktonic and biofilms states. Different methods were employed to verify the antimicrobial potential. Among these are the determination of minimum inhibitory concentration (MIC) determination of the death curve and evaluation of minimum bactericidal concentration (MBC). Furthermore, quantification of biomass and the number of viable cells of the biofilm were performed, respectively, by staining with crystal violet and counting colony forming units (CFU). The negative and positive controls used in all assays were respectively 4% DMSO and chlorhexidine gluconate with concentration adjusted according to the data of the MIC of each microorganism. To determine the toxicity of EEFGS, it was used the toxicity test on Artemia nauplii. The data showed that the extract and subfractions 13 to 17 of the chloroform fraction show a remarkable antimicrobial effect, able to inhibit the growth of planktonic and development of biofilms of S. oralis strain until the concentration of 62.5 &#956;g.mL-1. With respect to S. salivarius, only subfraction 12 interfered on bacterial growth. Regarding the toxicity, it was observed that death of Artemia nauplii occurred at higher concentrations than those that exhibited antibacterial effect. From these results it can be concluded that EEFGS and subfractions 13-17 can be used as agents for the control of biofilm formation of S. oralis. In addition, complementary methodologies that seek purification of the active compounds and their cytotoxic effects on eukaryotic cells need to be held, aiming its use as an herbal agent.
7

Investigação do potencial químico e farmacológico de Xylopia sericea A. St.-Hil. (Annonaceae)

Mendes, Renata de Freitas 28 July 2014 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-05-02T15:38:00Z No. of bitstreams: 1 renatadefreitasmendes.pdf: 1070020 bytes, checksum: 429a7ec44a9e4f2575f881684d3f64e0 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-06-03T13:00:10Z (GMT) No. of bitstreams: 1 renatadefreitasmendes.pdf: 1070020 bytes, checksum: 429a7ec44a9e4f2575f881684d3f64e0 (MD5) / Made available in DSpace on 2016-06-03T13:00:10Z (GMT). No. of bitstreams: 1 renatadefreitasmendes.pdf: 1070020 bytes, checksum: 429a7ec44a9e4f2575f881684d3f64e0 (MD5) Previous issue date: 2014-07-28 / Xylopia sericea, Annonaceae, espécie nativa do Brasil, é conhecida popularmente como “embiriba”, “banana-de-macaco”, “pindaíba”, “pimenta-de-macaco”. Além do uso das sementes como condimento, a espécie é utilizada no paisagismo, na indústria caseira de cordoaria e para fins medicinais no tratamento da dor, inflamação e desordens gastrointestinais. Os objetivos desse trabalho foram contribuir com o estudo de alguns dos usos medicinais da espécie e ampliar o conhecimento acerca de seu potencial químico e biológico. Para isso, os frutos de X. sericea foram extraídos com metanol para obtenção do extrato metanólico (EBM), e também tiveram seu óleo essencial (OXS) extraído por hidrodestilação. A análise fitoquímica de EBM foi realizada para identificação das principais classes de metabólitos especiais e a determinação dos teores de fenóis totais e flavonoides. OXS foi caracterizado por CG-EM. In vitro, foram avaliadas para EBM e OXS as atividades: antioxidante frente aos métodos do sequestro de radicais livres (DPPH), sistema β-caroteno/ácido linoleico e fosfomolibdênio; antibacteriana pela determinação da CIM (concentração inibitória mínima) e CBM (concentração bactericida mínima) para 10 cepas de importância clínica; leishmanicida para formas promastigotas de L. amazonensis e L. chagasi; citotóxica para as linhagens de células tumorais Jurkat, HL-60, MCF-7, THP-1, MDA-231, HCT-116 e células não tumorais VERO. In vivo, foi avaliada a atividade anti-inflamatória pelo modelo do edema de orelha induzido por óleo de cróton, por via oral (EBM) e tópica (EBM e OXS). A toxicidade aguda de EBM, bem como sua dose letal média (DL50) foram determinadas. Fenóis, flavonoides, cumarinas, saponinas, taninos, alcaloides e terpenoides/esteroides foram identificados em EBM, sendo o teor de fenóis totais 358,2 ± 33,1 mg/g em equivalentes a ácido tânico e o teor de flavonoides 28,8 ± 8,2 mg/g em equivalentes a quercetina. Foi possível identificar, por CG-EM, 63 substâncias que corresponderam a 80 % dos constituintes de OXS. Dentre elas, espatulenol (16,42 %), guaiol (13,93 %) e D - germacreno (8,11 %) foram as majoritárias. Quanto à atividade antioxidante, EBM e OXS apresentaram pelo método do DPPH, CI50 de 16,37 e 49,16 μg/mL, respectivamente; CI50 de 49,16 e 6,92 μg/mL pelo método do β-caroteno/ácido linoleico; 0,75 mg/mg de EBM e 2,30 mg/mg de OXS equivalentes à ácido ascórbico pelo método do fosfomolibdênio. Quanto à atividade antibacteriana, as cepas mais sensíveis à EBM foram S. aureus, E. cloacae e B. cereus, com CIM de 7,8; 7,8 e 31,25 μg/mL, respectivamente, para OXS, S. aureus, E. cloacae, K. pneumoniae e B. cereus com CIM de 7,8; 7,8; 62,5 e 15,63 μg/mL, respectivamente. Além disso, pode-se verificar que EBM e OXS apresentaram atividade bactericida para E. faecalis (1000 μg/mL) e para B. cereus (31,25 μg/mL), respectivamente. Em relação à atividade leishmanicida, EBM apresentou CI50= 42,51 μg/mL para L. amazonensis, porém não apresentou atividade contra as formas promastigotas de L. chagasi. OXS foi avaliada apenas para L. amazonensis e não apresentou atividade. EBM foi capaz de inibir a proliferação celular em 56 % para HL-60, não apresentando toxidade significativa para as demais células tumorais, inclusive as células VERO. A aplicação de EBM por via tópica reduziu o edema de orelha nas doses de 1; 0,5 e 0,1 mg/orelha em 41,8 %, 99,1 % e 56,9 %. OXS foi capaz de reduzir o edema nas doses de 1 e 0,5 mg/orelha em 43,4 % e 54,2 %. Por via oral, EBM foi capaz de reduzir o edema nas doses de 300, 100 e 50 mg/kg em 36,3 %, 29,5 % e 32,0 %. Não foram observados sinais de toxicidade para EBM por via oral, sendo a DL50 > 2000 mg/kg. Os resultados apresentados são relevantes uma vez que EBM e OXS apresentaram atividades biológicas promissoras o que justifica a continuação do estudo. / Xylopia sericea, Annonaceae, is a species native from Brazil, popularly known as "embiriba", "banana-de-macaco", "pindaíba", "pimento-de-macaco". Besides being used as condiment, the species is used in landscaping, in home rope factory and for medicinal purposes in the treatment of pain, inflammation, and gastrointestinal disorders. The aims of this study was to corroborate some of X. sericea medicinal use and to expand the chemical and biological knowledge on this species. For this, the fruits of X. sericea were extracted with methanol to obtain the methanolic extract (EBM), and also had its essential oil (OXS) extracted by hydrodistillation. The phytochemical study of EBM was conducted to identify the main classes of special metabolites and to determine of the contents of total phenols and flavonoids. OXS was characterized by GC-MS. In vitro, EBM and OXS were evaluated for the following activities: antioxidant by DPPH scavenging, β-carotene bleaching, and phosphomolybdenum assays; antibacterial by determining the MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) for 10 strains of clinical importance; leishmanial for promastigote forms of L. amazonensis and L. chagasi; cytotoxic against the tumor cell lines Jurkat, HL-60, MCF-7, THP-1, MDA-231, HCT-116 and no tumor Vero cells. The in vivo anti-inflammatory activity was evaluated by the croton oil-induced ear edema method, orally (EBM) and topically (EBM and OXS). The acute toxicity of EBM and the median lethal dose (LD50) were determined. Phenols, flavonoids, coumarins, saponins, tannins, alkaloids and terpenoids/steroids were identified in EBM. The content of total phenols was 358.2 ± 33.1 mg/g expressed as equivalent to tannic acid and of flavonoids was 28.8 ± 8 2 mg/g expressed as equivalents to quercetin. Sixty three compounds were identified in OXS corresponding to 80 % of the oil constituents. Among them, spathulenol (16.42 %), guaiol (13.93 %) and germacrene D (8.11 %) were the major. Regarding the antioxidant activity, EBM and OXS presented by the DPPH method, IC50 of 16.37 and 49.16 μg/mL, respectively; IC50 of 49.16 and 6.92 μg/mL by β-caroten bleaching method; 0.75 mg/mg of EBM and 2.30 mg/mg of OXS equivalents to ascorbic acid by phosphomolybdenum method. Results for antibacterial activity showed that the most sensitive strains to EBM were S. aureus, E. cloacae and B. cereus with MIC of 7.8; 7.8 and 31.25 μg/mL, respectively. To OXS, S. aureus, E. cloacae, K. pneumoniae and B. cereus showed the highest sensitivity with MIC of 7.8; 7.8; 62.5 and 15.63 μg/mL, respectively. Furthermore, it was observed that EBM and OXS showed bactericidal activity for E. faecalis (1000 μg/mL) and B. cereus (31.25 μg/mL), respectively. Regarding leishmanicidal activity, EBM showed IC50 of 42.51 μg/mL for L. amazonensis, but showed no activity against L. chagasi. Moreover, OXS was evaluated only for L. amazonensis and showed no activity. EBM was able to inhibit cell proliferation by 56% for HL-60 and showed no significantive toxicity to the other tumor cells, and also Vero cells. Topical application of EBM reduced the ear edema caused by croton oil by 41.8 %, 99.1 % and 56.9 % at doses of 1; 0.5 and 0.1 mg/ear. OXS was able to reduce the edema at the doses of 1 and 0.5 mg/ear by 43.4 % and 54.2 %. Orally, EBM was able to reduce the edema at doses of 300, 100 and 50 mg/kg by 36.3 %, 29.5 % and 32.0 %. No signs of toxicity were observed for EBM, with an LD50 > 2000 mg/kg. The results are relevant since EBM and OXS showed promising biological activities which justifies the continuation of the study.
8

Effects of prescribed fire timing on vigor of sericea lespedeza in the Kansas Flint Hills

Alexander, Jonathan Andrew January 1900 (has links)
Master of Science / Department of Animal Sciences and Industry / K C Olson / We evaluated effects of annual, prescribed burning on vigor of the noxious weed, sericea lespedeza (Lespedeza cuneata; SL) in native tallgrass prairie over a 4-yr period. We hypothesized that annual prescribed burning conducted during the growing season would selectively pressure SL, whereas locally-conventional, dormant-season prescribed burning would have no effect on SL. A 50-ha native tallgrass pasture infested with SL (initial basal frequency = 2 ± 1.3%, initial aerial frequency = 36 ± 3.4%) was used for our study. It was divided along watershed boundaries into 9 fire-management units (5 ± 2.6 ha) for this experiment. Burn units were assigned randomly to 1 of 3 prescribed-burning times (n = 3 / treatment): early spring (1 April; EARLY), mid-summer (1 August; MID), or late summer (1 September; LATE). Forage biomass, SL aerial frequency, SL stem length, SL seed production, soil cover, and plant species composition were measured along single, permanent 100-m transects in each burn unit. Treatment and measurement date influenced forage biomass and SL stem length (treatment × time). Forage biomass was not different (P ≥ 0.43) between treatments on 17 July; however, forage biomass was greater (P < 0.01) in EARLY than MID and greater in MID than LATE on 10 October. Maximum stem length of SL was less (P ≤ 0.02) in MID and LATE than in EARLY on 17 July and on 10 October. Aerial frequency of SL was least (main effect – P < 0.01) in LATE, intermediate in MID, and greatest in EARLY, whereas basal frequency of SL was less (P < 0.01) in MID and LATE compared with EARLY. Whole-plant dry weight and seed production of SL at dormancy were greatly diminished (P ≤ 0.02) in MID and LATE compared with EARLY. Occurrence of bare soil, litter cover, and total basal plant cover were not different (P ≥ 0.21) between treatments. Similarly, basal cover of grasses, forbs, and shrubs were not different (P ≥ 0.24) between treatments. We interpreted these data to indicate that annual prescribed burning during the growing season had strong suppressive effects on SL compared to locally-conventional, early-season prescribed burning and produced no apparent detrimental effects on soil cover or non-target plant species. Post-fire regrowth was sufficient to prevent erosion and soil-moisture loss during the subsequent dormant season and would have allowed light to moderate grazing during the ensuing winter. Key words: Lespedeza cuneata, prescribed fire, range improvement
9

Chemical study of two Xylopia species and resolution of natural products by matrix assisted diffusion ordered spectroscopy (MAD) / Estudo QuÃmico de duas espÃcies de xylopia (Annonaceae) e resoluÃÃo de misturas de produtos naturais por espectroscopia ordenada por difusÃo assistida por matriz (MAD)

Mariano George Sousa Vieira 05 September 2014 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Xylopia nitida and Xylopia sericea are commonly known as âembira-brancaâ and âpimenta do sertÃoâ, respectively, belonging to Annonaceae family. The chromatographic analysis of X. nitida roots allowed isolation of a trachlyobane diterpene, ent-trachlyoban-18,19-diol and its acetylated product, ent-18,19-diacetoxy-trachylobane, a kaurene diterpene, ent-kaur-16-en-18,19-diol, two aporphinic alkaloids, 5,6,6a,7-tetrahydro-1-methoxy-(6aS)-4H-benzo[de][1,3]benzodioxolo[5,6-g]quinoline e xylopine, and a glucoside, named 1-O-ethyl-&#946;-D-glucopiranose. Also using chromatographic analysis of X. sericea fruits were obtained a kaurane diterpene, kauran-16&#946;-ol and a diterpenes mixture, ent-kaur-16-en-19-oic acid and beyer-15-19-oic acid. The structures of these compounds were elucidated by spectroscopic studies (IR, MS and NMR). In the second part of this work, has been showed the diffusion-ordered spectroscopy (DOSY) as a powerful tool in natural product mixture analysis. The assignment of NMR signals to specific components in a mixture is a challenging task. DOSY has provided important progress in this area, allowing the signals originating from individual components of different molecular sizes to be distinguished. However, when the sizes of the compounds are similar and/or the spectra are overlapped, signal assignment can easily become intractable. The use of a co-solute in a matrix-assisted DOSY (MAD) experiment can be a useful solution, improving diffusional (and sometimes spectral) resolution by exploiting selective binding to the matrix. The challenge is to apply MAD to molecules with high structural similarity, for example in natural product mixtures. Various surfactants, including SDS, AOT and CTAB have previously been shown to be effective in MAD analysis. Here we present an important addition, the Brij family of nonionic surfactants. We demonstrate the use of Brij micelles and other systems in mixed solvents with a variety of mixtures relevant to natural products. / Xylopia nitida e X. sericea, conhecidas popularmente como embira-branca e pimenta do sertÃo, respectivamente, sÃo espÃcies pertencentes à famÃlia Annonaceae. A anÃlise cromatogrÃfica dos extratos hexÃnico e etanÃlico das raÃzes de X. nitida possibilitou o isolamento de um diterpeno de esqueleto traquilobano, ent-traquiloban-18,19-diol e seu derivado acetilado, ent-18,19-diacetÃxi-traquilobano, um diterpeno de esqueleto caureno, ent-caur-16-en-18,19-diol, dois alcalÃides aporfÃnicos, 5,6,6a,7-tetraidro-1-metoxi-(6aS)-4H-benzo[de][1,3]benzodioxolo[5,6-g]quinolina e xylopina e um glicosÃdeo, 1-O-etil-&#946;-D-glicopiranose, todos de carÃter inÃdito na literatura, exceto os dois Ãltimos. AtravÃs da anÃlise cromatogrÃfica do extrato hexÃnico dos frutos de X. sericea foi possÃvel obter um diterpeno de esqueleto caurano denominado cauran-16&#946;-ol e uma mistura de diterpenos, Ãcido ent-caur-16-en-19-Ãico e Ãcido beier-15-en-19-Ãico. O isolamento dos constituintes quÃmicos presentes nos extratos da raiz e frutos de X. nitida e X. sericea, respectivamente, foi realizada por mÃtodos cromatogrÃficos convencionais e a determinaÃÃo estrutural das substÃncias isoladas foi realizada a partir de mÃtodos espectromÃtricos como: IV, EM, RMN 1H, 13C e DEPT 135 incluindo tÃcnicas bidimensionais como, COSY, HSQC e HMBC. A primeira parte deste trabalho relata o estudo quÃmico das raÃzes de X. nitida e dos frutos de X. sericea. A espectroscopia ordenada por difusÃo ou DOSY (Diffusion Ordered Spectroscopy) provà um meio para uma âseparaÃÃo virtualâ de compostos, atravÃs de um mapa bidimensional onde em um eixo temos o deslocamento quÃmico e em outro observamos o coeficiente de difusÃo (D) das molÃculas na mistura. A separaÃÃo de sinais somente à possÃvel quando espÃcies difundem a diferentes velocidades. Na quÃmica de produtos naturais, frequentemente nos deparamos com misturas de compostos quimicamente semelhantes e de tamanhos muito similares, o que torna limitado o experimento DOSY tradicional. Entretanto, o coeficiente de difusÃo das substÃncias pode ser modificado pela adiÃÃo de co-solutos e/ou co-solventes, surgindo a partir daà a espectroscopia ordenada por difusÃo assistida por matriz (matrix-assisted DOSY ou MAD). VÃrios surfactantes, incluindo SDS, AOT e CTAB tÃm se mostrado efetivos em anÃlises por MAD. Neste trabalho, experimentos MAD foram realizados com algumas misturas de produtos naturais com similaridades estruturais utilizando o Ãcido perfluoro-octanÃico (PFOA), polivinilpirrolidona (PVP) e os surfactantes Brij 78 e 98, que por sua vez, ainda nÃo haviam sido utilizados para esse propÃsito. NÃs tambÃm demonstramos a formaÃÃo de micelas de Brij 78 e 98 em misturas dos solventes DMSO-d6 e D2O.
10

Impacts of patch-burn grazing on livestock and vegetation in the tallgrass prairie

Rensink, Cade Brion January 1900 (has links)
Master of Science / Department of Agronomy / Walter H. Fick / Patch-burn grazing is a relatively new concept in terms of rangeland management. While numerous benefits have been associated with this system, in the tallgrass prairie of Kansas, cattle production and sustainability of rangeland are critical. In 2006, 253 ha at the KSU Bressner Range Research Unit in Woodson County, Kansas were subjected to spring patch-burn grazing (using one-third portions) and traditional full-burn grazing. Each treatment within the split-block design was replicated four times for 3 years. The objectives were to evaluate whether livestock performance would be compromised under this grazing system, to monitor the health of the rangeland, and to observe the usefulness of this tool as a potential control of the invasive plant sericea lespedeza [Lespedeza cuneata (Dumont) G. Don]. In regards to cattle performance, burn treatments had no significant difference in average daily gain (p≥0.10) in any of the 3 years. On average, cattle utilized 61% of the current year’s forage production in patch-burned portions, which was higher (p≤0.10) than that of unburned (30%) and full-burn (41%) portions. Results of the botanical composition show forb and woody plant composition did not differ between treatments, however differences (p≤0.10) were present in grass composition. Total annual grasses increased 19.1 percentage units under patch-burn and 2.1 units under full-burn, while total perennial grasses decreased 18.4 and 1.1 units, respectively. When evaluated by treatment area (one-third portion), results indicated that the 3-year cycle did allow enough time for recovery. At 2 years after treatment (2-YAT), no significant difference in composition(p≥0.10) was present between initial patch-burn portions and the full-burn pastures. Finally, in only 1 year of the study did cattle statistically consume a greater percentage of sericea lespedeza plants (p≤0.10) in the patch-burned portions (92%) than in full-burned pastures (35%). Biomass utilization did not differ (p≥0.10) between burn treatments. Surprisingly, there was a trend for the number of plants in the sampled areas of the patch-burn portions to decrease throughout the cycle. However, at the conclusion of the 3-year cycle, sericea densities did not differ(p≥0.10) between treatments. Patch-burn grazing shows promise as a potential management tool for Kansas land managers.

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