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Use of liquid chromatography for assay of flavonoids as key constituents and antibiotics as trace elements in propolis. Investigation into the application of a range of liquid chromatography techniques for the analysis of flavonoids and antibiotics in propolis; and extraction studies of flavonoids in propolisKamble, Ujjwala Kerba January 2016 (has links)
Propolis is an approved food additive containing flavonoids as a major active constituent. Variability has been found in the composition of propolis in distinctive regions and it was noticed that there are limitations in the analysis of propolis. In this study, the identification of ten flavonoids and residual antibiotics in propolis was investigated by using several liquid chromatography techniques, including reversed-phase high-performance liquid chromatography (RP-HPLC), microemulsion LC (MELC) and ultra-performance LC (UPLC). The ten flavonoids that were selected for this research include rutin, myricetin, quercetin, apigenin, kaempferol, pinocembrin, CAPE, chrysin, galangin and acacetin while chlortetracycline, oxytetracycline and doxycycline were selected to examine the residual antibiotics in propolis. For the analysis of the selected flavonoids, routine RP-HPLC method was found to be the best method, while MELC technique was found more efficient for the analysis of the selected antibiotics. Solid phase extraction with HLB sorbent was utilised in the analysis of antibiotics for clean-up of propolis. In method development studies for flavonoids and antibiotics, one-factor-at-a-time (OFAT) approach was followed. The final optimised method for the analysis of flavonoids as well as the method.
for the analysis of antibiotics was validated using the ICH guidelines, and various aspects, such as the linearity, selectivity, accuracy, recovery, robustness and stability parameters, were examined. Development of efficient conventional method for the extraction of flavonoids from propolis was studied extensively in the present research work using different extraction techniques such as maceration, hot extraction, ultrasound assisted extraction. Among all extraction experiments, ethanolic extraction using ultrasound extraction method was the best efficient approach.
This thesis shows that, in general, the performance of O/W MELC is superior to that of conventional HPLC for the determination of residual antibiotics in propolis. UPLC was not suitable for the analysis of flavonoids and antibiotics. The conventional LC was the only technique to separate the ten flavonoids but MELC was able to separate nine of the flavonoids with faster analysis time. This work also showed that MELC uses cheaper solvents. This considerable saving in both cost and time will potentially improve efficiency within quality control. / Social Justice Department, Government of Maharashtra, India.
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The Production of 2-Keto-L-Gulonic Acid by Different Gluconobacter StrainsNassif, Lana Amine 14 February 1997 (has links)
Vitamin C is industrially produced by the Reichstein method, which uses gluconobacters to oxidize sorbitol to sorbose then a chemical process to convert sorbose to 2-keto-L-gulonic acid (2-KLG). The establishment of a more extensive microbial process for 2-KLG production translates into a less expensive and more efficient production of vitamin C. I examined pure strains and mixed cultures for their ability to produce 2-KLG using thin layer and high performance liquid chromatography. The DSM 4027 mixed culture produced the highest yield, 25 g/L, of 2-KLG from 100 g/L of sorbose, while the gram-negative rods isolated from DSM 4027 produced 8.8 g/L, and B. megaterium isolated from DSM 4027 produced 1.4 g/L. Thus, the gram-negative rods in the mixed culture were the primary 2-KLG producer, but B. megaterium in the DSM 4027 mixture enhanced this synthesis. Authentic pure cultures of Gluconobacter oxydans IFO strain 3293 and ATCC strain 621 produced 3.4 g/L and 5.7 g/L, respectively. Attempts to co-culture the isolated B. megaterium with the isolated gram-negative rods and authentic Gluconobacter strains did not increase 2-KLG production, nor did growing the cultures on B. megaterium spent media. Bacillus megaterium produced an unidentified keto-compound detected on the TLC chromatograms, which suggested that B. megaterium converted sorbose to an intermediate that may then be converted by the gram-negative rods in DSM 4027 to 2-KLG. Limited phenotypic tests suggested that the gram-negative rods in the DSM 4027 mixture are not gluconobacters. / Master of Science
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Potential and limits of Raman spectroscopy for carotenoid detection in microorganisms: implications for astrobiologyJehlička, J., Edwards, Howell G.M., Osterrothova, K., Novotna, J., Nedbalova, L., Kopecky, J., Nemec, I., Oren, A. 13 December 2014 (has links)
No / In this paper, it is demonstrated how Raman spectroscopy can be used to detect different carotenoids as possible biomarkers in various groups of microorganisms. The question which arose from previous studies concerns the level of unambiguity of discriminating carotenoids using common Raman microspectrometers. A series of laboratory-grown microorganisms of different taxonomic affiliation was investigated, such as halophilic heterotrophic bacteria, cyanobacteria, the anoxygenic phototrophs, the non-halophilic heterotrophs as well as eukaryotes (Ochrophyta, Rhodophyta and Chlorophyta). The data presented show that Raman spectroscopy is a suitable tool to assess the presence of carotenoids of these organisms in cultures. Comparison is made with the high-performance liquid chromatography approach of analysing pigments in extracts. Direct measurements on cultures provide fast and reliable identification of the pigments. Some of the carotenoids studied are proposed as tracers for halophiles, in contrast with others which can be considered as biomarkers of other genera. The limits of application of Raman spectroscopy are discussed for a few cases where the current Raman spectroscopic approach does not allow discriminating structurally very similar carotenoids. The database reported can be used for applications in geobiology and exobiology for the detection of pigment signals in natural settings.
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Molecular characterization of aflatoxigenic and non-aflatoxigenic aspergillus isolatesMngadi, Phakamile Truth January 2007 (has links)
Thesis (M.Tech.: Biotechnology)- Dept. of Biotechnology & Food Technology, Durban University of Technology, 2007 xv, 102 leaves / For decades the genus Aspergillus (of fungi) has been classified based on morphological and growth criteria. Members of the Aspergillus section Flavi are economically valuable and methods of differentiating them are thus very important. Several molecular methods have been developed to distinguish these strains. Also, a number of biochemical and genetic studies have been used in order to provide a better means of classification (Lee et al., 2004). Aflatoxins, the most frequently studied mycotoxins, are produced by certain Aspergillus species/strains/isolates of fungi. The aflatoxin biosynthetic pathway studies have led to a number of discoveries. Several structural and regulatory genes (and their enzymes) involved in the biosynthesis of aflatoxins have been discovered and purified (Trail et al., 1995). Aflatoxin production and contamination of agricultural crops are major causes of economic losses in agriculture. Thus, better methods of characterization/differentiation are required for both aflatoxigenic and non-aflatoxigenic isolates. Molecular biology is one of the current tools used to differentiate between these isolates. Polymerase Chain Reaction (PCR)-based randomly amplified polymorphic DNA (RAPD) analysis has been used successfully in the analysis of DNA relatedness of species of fungi, bacteria, plants and animals. Dendograms which evaluate/assess the likeness between different isolates has also been used (Martinez et al., 2001). Restriction fragment length polymorphism (RFLP) analysis has been applied to a number of studies to detect differences between fungi and to establish relationships between them. Therefore, the scope of this study was to investigate RAPD analysis (with dendograms) and detection of RFLPs by hybridization as molecular methods that can distinctly differentiate or characterize the aflatoxigenic and non-aflatoxigenic Aspergillus isolates.
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Optimisation of HPLC-based methods for the separation and detection of herbicide glyphosate and its major metabolite in waterMadikizela, Lawrence Mzukisi January 2010 (has links)
Dissertation submitted in partial compliance with the requirements for the Masters Degree in Technology, 2010. / Water storage dams play an important part in the collection and purification of water destined
for human consumption. However, the nutrient rich silt in these dams promotes rapid growth
of aquatic plants which tend to block out light and air. Glyphosate is universally used as the
effective non-selective herbicide for the control of aquatic plants in rivers and dams.
Invariably there is residual glyphosate present in water after spraying of dams and rivers with
glyphosate herbicide. The amount of residual glyphosate is difficult to determine on account
of high solubility of glyphosate in water. Thus a method of sample preparation and a sensitive
HPLC method for the detection of trace amounts of glyphosate and its major metabolite
aminomethylphosphonic acid (AMPA) in water is required. A crucial step in sample
preparation is pre-column derivitization of glyphosate with 9-fluorenylmethyl chloroformate
(FMOC-Cl).
For sample pretreatment, water samples were derivatized with FMOC-Cl at pH 9, extracted
with ethyl acetate and sample clean-up was carried out by passing a sample through the SPE
cartridge. For SPE, recovery studies were done to choose a suitable cartridge for glyphosate
and AMPA analysis. The following cartridges were compared, namely, C18, Oasis HLB and
Oasis MAX SPE cartridges. Best recoveries (101% for glyphosate and 90% for AMPA) were
obtained using 500 mg of C18 solid-phase extraction cartridge. The eluent from SPE cartridge
was injected into HPLC column. Three types of separation columns (namely; C18 column,
silica based amino column and polymeric amino column) were compared for the separation
of glyphosate and AMPA. The best separation of glyphosate and AMPA in water samples
was achieved using a polymeric amino column and a mobile phase at pH 10 which contained
a mixture of acetonitrile and 0.05 M phosphate buffer (pH 10) 55:45, (v/v) respectively.
The method was validated by spiking tap water , deionized water and river water at a level of
100 μg/l. Recoveries were in the range of 77% -111% for both analytes. The method was also
used in determining the levels of glyphosate and AMPA in environmental samples. This
method gave detection limits of 3.2 μg/l and 0.23 μg/l for glyphosate and AMPA
respectively. The limits of quantification obtained for this method were 10.5 μg/l and 3.2 μg/l
for glyphosate and AMPA respectively. / Eskom Tertiary Education Support Programme (TESP) Durban University of Technology.
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Spontaneous metathesis of bis-chelated PdII(L-S,O)2 complexes in solution : a rp-HPLC studyVan der Molen, Lynndal 03 1900 (has links)
Thesis (MSc (Chemistry and Polymer Science))--Stellenbosch University, 2008. / N,N-dialkyl-N-acyl(aroyl)thiourea ligands form stable chelated complexes in a cis
configuration with the platinum group metals. Such chelated complexes are generally
considered substitutionally “inert” in solution, however, it was found that cis-bis(N,Ndialkyl-
N-acyl(aroyl)thioureato)M(II) complexes (M = Ni(II), Pd(II) or Pt(II)) readily
undergo facile chelate metathesis reactions in solution at room temperature. Upon
mixing two different parent complexes, a mixed-ligand product formed in solution, with
an equilibrium, or steady state, between the two parent complexes and the mixed-ligand
product being attained after a period of time: M(LA)2 + M(LB)2 M(LA)(LB). All three
complexes remained in solution even with a ten-fold excess of one parent complex.
The presence of the mixed-ligand products in solution was confirmed by
liquid chromatography-mass spectrometry (LC-MS), nuclear magnetic resonance
(NMR) spectra and a crystal structure of the mixed-ligand complex
cis-Pd(L3-S,O)(L4-S,O). Though a number of attempts were made, it was not possible
to either isolate or synthesise the mixed-ligand complexes exclusively.
The equilibrium distribution and the rate of the metathesis reaction were influenced by a
number of factors, including the central metal ion, the substituents on the complexed
ligands and the reaction medium. In addition to these, a number of other factors, some
unexpected, also played a role in the rate of the reaction. Initial concentration of the
parent complexes, the age of the solutions upon mixing and the presence of impurities
or additives all contributed to the overall rate of reaction. The results from these rate
studies highlighted the necessity for extensively purified compounds.
In addition to chelate metathesis reactions, the exchange between a cis-Pd(L-S,O)2
complex and an unbound HL ligand in solution was also investigated. Again, even with
an excess of unbound ligand, all three possible complexes were present in solution.
It has been shown previously that these complexes undergo a photoinduced cis-trans
isomerisation under intense light, and it has been proposed that the reverse trans-cis
process, which occurs in the dark, may be a metathesis reaction. In light of this, the
relationship between these chelate metathesis reactions and the reverse trans-cis
reaction was briefly investigated.
Though the metathesis reactions were a general phenomenon in the Ni(II), Pd(II) and
Pt(II) complexes of the aforementioned ligands, the experiments focused mainly on the
cis-Pd(L-S,O)2 complexes due to the favourable timescales of their metathesis
reactions. The primary technique to observe these reactions was reversed-phase
high-performance liquid chromatography (rp-HPLC). The timescales involved in the
cis-Pd(L-S,O)2 metathesis reactions as well as the stability of the Pd(II) complexes
under the HPLC conditions made this technique ideal.
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Multidimensional fractionation of wood-based tanninsRadebe, Nonhlanhla Mtandi 03 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: High molar mass tannin extracts are complex mixtures which are distributed in both molar mass and chemical composition. Condensed tannins from quebracho and mimosa and hydrolysable tannins of tara, chestnut wood and turkey gall were studied. Application of a single analytical technique is not sufficient to elucidate the complete structures present in the extracts. 13C Nuclear Magnetic Resonance (NMR) spectroscopy and Matrix Assisted Laser Desorption/Ionisation Time-of-Flight (MALDI-TOF) mass spectrometry were applied in order to determine the chemical composition and molar mass, respectively. A new mass spectrometric method that can uniquely determine the oligomer microstructure was developed using Collision Induced Dissociation (CID) experiments. Bulk analysis only showed the average composition of the extracts, in order to obtain specific information on the molar mass and chemical composition distributions. Hydrophilic Interaction Liquid Chromatography (HILIC) was used for analysis of the condensed tannins and for the hydrolysable tannins Normal Phase Liquid Chromatography (NP-LC) was utilised. The HILIC separation was up-scaled and the fractions were collected and analysed by MALDI-TOF, and this coupling revealed that separation occurs by molar and chemical composition. For separation of the molecules only by size, Size Exclusion Chromatography (SEC) analyses were carried out; this allowed for relative comparison of the tannin molecules. In conclusion, for characterisation of high molar mass tannins a multi-dimensional approach was necessary since the various distributions present in these extracts are superimposed. / AFRIKAANSE OPSOMMING: Hoë molekulêre massa tannienekstrakte is komplekse mengsels, in terme van beide molekulêre massa en chemiese samestelling. Gekondenseerde tanniene vanaf quebracho en mimosa, en hidroliseerbare tanniene vanaf tara, kastaaiinghout en Turksegal is bestudeer. Die gebruik van ‘n enkele analitiese tegniek is nie voldoende om die volledige struktuur van komponente teenwoordig in die ekstrakte te analiseer nie. 13C KMR-spektroskopie en MALDI-TOF-massaspektroskopie is gebruik om die chemiese samestelling en molekulêre massa, onderskeidelik, te bepaal.
‘n Nuwe metode is ontwikkel vir die bepaling van die oligomeer-mikrostruktuur deur gebruik te maak van botsings-geïnduseerde dissosiasie eksperimente. Grootmaat analise het net die gemiddelde samestelling van die ekstrak bepaal. Hidrofiliese-interaksie-vloeistofchromatografie (HILIC) is gebruik vir die analise van gekondenseerde tanniene en gewone fase-vloeistofchromatografie is gebruik vir die hidroliseerbare tanniene. Die HILIC-skeiding is op groter skaal uitgevoer en die fraksies is versamel en gebruik vir MALDI-TOF analise. Hierdie koppeling het getoon dat skeiding plaasvind op grond van molekulêre massa en chemiese samestelling.
Grootte-uitsluitingschromatografie is gebruik vir die skeiding van molekules alleenlik op grootte. Hierdeur kon ‘n relatiewe vergelyking van die tannienmolekules gemaak word.
Vir die karakterisering van hoë molekulêre massa tanniene is ‘n multi-dimensionele benadering nodig aangesien die verskeie verspreidings teenwoording in hierdie ekstrakte supergeponeerd is.
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The impact of storage time and seasonal harvesting on biomarker levels of Lessertia frutescensCampbell, James January 2012 (has links)
<p>In South Africa, it is estimated that approximately 70% of the population frequently make use of traditional medicinal plants for their health care needs. The use of Lessertia frutescens by the  / various cultural groups in South Africa dates back to the earlier civilizations and continues to be used today to treat a multitude of ailments. To get the best results from a medicinal plant, one  /   / would need to ensure that the crude material is of good quality through interventions like being properly grown, well dried and correctly processed. This would add a measure of quality  / assurance, which will contribute towards the safety and efficacy aspect of herbal medicine. The aim of this study was to investigate what impact a particular season of harvest and the time in  / storage would have on the flavonoid and triterpenoid marker levels of Lessertia frutescens. To achieve this, the following was investigated: (1) storage variation of Lessertia frutescens leaves  / by comparing the results obtained from the High Performance Liquid Chromatography (HPLC) analysis of the flavonoids and triterpenoids, (2) seasonal variation of Lessertia frutescens  / leaves by comparing the results obtained from the HPLC analysis of the flavonoids and triterpenoids, (3) leaf and stem variation of Lessertia frutescens by comparing the results obtained from HPLC analysis of the flavonoids and triterpenoids. The hypotheses were: (1) the stored sample would indicate the same level of the biomarkers for the flavonoids and triterpenoids, as that of  / the freshly prepared sample, (2) the sample that was harvested during the summer season would indicate higher levels of the biomarkers of  / flavonoids and triterpenoids than the other three  / seasons, (3) the leaf sample would indicate the same level of the biomarkers for the flavonoids and triterpenoids, as that of the stem sample. An Agilent 1200 series HPLC was used for the  / determination of the flavonoids sutherlandin A and sutherlandin D as well as the triterpenoids sutherlandioside B and sutherlandioside D. Results show that for both sutherlandin A (summer:  / 3.67 ± / 2.88 mg/ml / storage: 4.07 ± / 2.88 mg/ml) and D (summer: 4.10 ± / 1.06 mg/ml / storage: 4.25 ± / 1.06 mg/ml) show significantly (P < / 0.0001) higher concentrations in the case of the storage  / amples. For both sutherlandioside B (summer: 3.01 ± / 0.39 mg/ml / storage: 2.82 ± / 0.39 mg/ml) and D (summer: 5.82 ± / 0.42 mg/ml / storage: 4.66 ± / 0.42 mg/ml) show significantly (P < /   / .0001)  / higher concentrations in the case of the fresh summer samples.For the seasonal comparison, results show that for sutherlandin A (summer: 3.67 ± / 12.49 mg/ml / autumn: 4.75 ± /   / 12.49 mg/ml / winter: 4.23 ± / 12.49 mg/ml / spring: 6.56 ± / 12.49 mg/ml) show significantly (P < / 0.0001) higher concentrations in the case of the spring sample. For sutherlandin D (summer: 4.10  /   / 10.32 mg/ml / autumn: 6.37 ± / 10.32 mg/ml / winter: 5.25 ± / 10.32 mg/ml / spring / 6.08 ± / 10.32 mg/ml) show significantly (P < / 0.0001) higher concentrations in the case of the autumn sample. For both sutherlandioside B (summer: 3.01 ± / 7.19 mg/ml / autumn: 2.15 ± / 7.19 mg/ml / winter: 2.89 ± / 7.19 mg/ml / spring: 1.47 ± / 7.19 mg/ml) and D (summer: 5.82 ± / 14.48 mg/ml / autumn: 3.33 ± / 14.48 mg/ml / winter: 4.23 ± / 14.48 mg/ml / spring: 2.50 ± / 14.48 mg/ml) show significantly (P < / 0.0001) higher concentrations in the case of the autumn sample. For the summer  / leaf/stem comparison, results show that for sutherlandin A (leaf: 3.67 ± / 8.18 mg/ml / stem: 4.67 ± / 8.18 mg/ml) show significantly (P < / 0.0001) higher concentrations in the case of the stem  / sample. For the sutherlandin D (leaf: 4.10 ± / 4.81 mg/ml / stem: 3.31 ± / 4.81 mg/ml) show significantly (P < / 0.0001) higher concentrations in the case of the summer leaf sample. For both the  / sutherlandioside B (leaf: 3.01 ± / 4.24 mg/ml / stem: 3.62 ± / 4.24 mg/ml) and D (leaf: 5.82 ± / 0.42 mg/ml / stem: 5.80 ± / 0.42 mg/ml) show significantly (P < / 0.0001) higher concentrations in the  / case of the stem samples. Results demonstrate that the production of secondary metabolites are influenced by  /   / environmental factors like seasonal harvesting, as indicated by the variation in the chemical constituent composition of Lessertia frutescens depending on the season collected in. Moreover, the storage of Lessertia frutescens for a period of one year resulted in an  / increase of two of the four constituents being monitored. There was slight variations in the chemical constituents, depending on whether the leaf or stem material of Lessertia frutescens was being used. Finally, the type of chemical constituent being monitored was also important in the consideration of this study. Therefore, this study can be seen as a starting point to further  /   / investigations of these aspects, which are of clinical, pharmacological and economic</p>
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Characterization of Microorganisms of Interest to Homeland Security and Public Health Utilizing Liquid Chromatography/Mass SpectrometryEverley, Robert A. 01 January 2008 (has links)
Liquid chromatography/quadrupole time of flight mass spectrometry (LC/QTOF MS) utilizing electrospray ionization was employed to monitor protein expression in Escherichia coli and Shigella organisms. Automated charge state deconvolution, spectral subtraction and spectral mirroring were used to reveal subtle differences in the LC/MS data. Reproducible intact protein biomarkers were discovered based on their unique mass, retention time and relative intensity. These markers were implemented to differentiate closely related strain types, (e.g. two distinct isolates of E. coli O157:H7) and to correctly identify unknown pathogens. Notable, was the distinction of multiple serotypes of enterohaemorrhagic E. coli which cannot be distinguished by clinical manifestation alone. Additionally, speciation of Shigella was achieved, a task for which no commercial real-time polymerase chain reaction (PCR) primers exist. This method was subsequently applied to two pathogenic Clostridium species: C. difficile and C. perfringens. Due to the increased difficulty during lysis, two new lysis protocols were developed, and each extracted a distinct set of proteins (by both mass and retention time). Extracts from both lysis procedures were utilized to discover biomarkers useful for identification and characterization at the species and strain levels. These biomarkers were successfully implemented to identify unknowns during a blind study and would enhance serological and genetic approaches by serving as new targets for detection. Two sets of the C. perfringens isolates that were deemed 100% similar by the gold standard for strain differentiation, pulsed-field gel electrophoresis (PFGE), were distinguished using LC/MS, demonstrating the high specificity of this approach. The final part of this work demonstrated the application of ultra performance liquid chromatography (UPLC) to this project to improve the throughput of the method. Given that numerous small molecule applications of UPLC have been published, efforts were made to examine the potential of UPLC to enhance the separation of intact proteins. Beginning with typically employed conditions, column temperature and organic solvent were optimized followed by an HPLC vs. UPLC comparison. When applied to a mixture of ten protein standards, the optimized UPLC method yielded improved chromatographic resolution, enhanced sensitivity, and a three-fold increase in throughput. Application of this method to cell lysate analysis demonstrated no compromise in chromatographic or mass spectral data quality; a reduction in run time from 75 minutes to 25 minutes was achieved.
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Estudo Químico e Biológico do extrato metanólico dos capítulos de Paepalanthus acanthophyllus Ruhland (Eriocaulaceae) /Ignácio, Felipe Gregório. January 2016 (has links)
Orientadora: Lourdes Campaner dos Santos / Banca: Isabele Rodrigues Nascimento / Banca: Marcelo Aparecido da Silva / Resumo: Paepalanthus é um dos gêneros mais representativos da família Eriocaulaceae e consta na literatura que já foram isoladas naftopiranonas e flavonoides, substâncias com comprovadas atividades como antirradicalar, antiúlcera e mutagênica. Apesar dos estudos realizados até o momento com espécies de Eriocaulaceae, é importante destacar que ainda existe um grande número de espécies que não foram estudados química e biologicamente. Portanto, neste trabalho descrevemos o estudo químico e biológico do extrato metanólico dos capítulos de Paepalanthus acanthophyllus. A estratégia de fracionamento por HPLC-PDA em escala semipreparativa do extrato metanólico permitiu isolar as substâncias 6-metoxicanferol-3-O-(6"-p-cumaroil)-β-D-glucopiranosil-7-O-β-D-glucopiranosídeo, Pa2, 6-metoxicanferol-3-7-di-O-β-D-glucopiranosídeo,Pa1, 6-metoxicanferol-3-O-β-D-glucopiranosídeo, Pa3, Paepalantina-9-O-β-D-glucopiranosideo, Pa4 e a Paepalantina, Pa5. A padronização do extrato metanólico foi realizada por meio da quantificação dos derivados do canferol glicosilados (Pa1, Pa2 e Pa3) e do derivado da paepalantina glicosilada (Pa4) por HPLC-PDA. A metodologia permitiu avaliar os parâmetros de linearidade, limites de detecção e quantificação.Os limites de detecção (12,22 μg.mL-1) e quantificação (30,03 μg.mL-1) foram satisfatórios para as condições analisadas para os derivados do canferol. Para o derivado da paepalantina glicosilada observou-se os valores de limite de detecção 25,54μg.mL-1 e de quantifica... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Paepalanthus is one of the most representative genus of the Eriocaulaceae family and it is known in literature that naphthopyrano nes and flavonoids were isolated. These substances are proven to have antiradical, antiulcer and mutagenic biological activities. Despite available studies of the Eriocaulaceae species, it is important to emphasize that there is still a large number of sp ecies that have not been studied chemically and biologically. Therefore, in this work we describe the chemical and biological study of the m ethanol extract of the capitula from Paepalanthus acanthophyllus . The fractionation strategy by HPLC - PDA semiprepa rative scale of the methanolic extract allowed us to isolate substances 6 - methoxykaempferol - 3 - O - (6" - p - coumaroyll) - β - D - glucopyranosyl - 7 - O - β - D - glucopyranoside, Pa2, 6 - methoxyKaempferol - 3 - 7 - di - O - β - D - glucopyranoside, Pa1, 6 - methoxyKaempferol - 3 - O - β - D - glucopyr anoside, Pa3, p aepalantina - 9 - O - β - D - glucopyranoside, Pa4 and p aepalantin e Pa5 . The standardization of the methanol extract was performed by quantification of glycosides kaempferol derivatives and paepalantina glycosylated by HPLC - PDA. The methodology allow ed us to evaluate the parameters: linearity, limits of detection and quantification. The detection limits (12.22 μ g.mL - 1 ) and quantitation (30.03 μ g.mL - 1 ) were satisfactory for the conditions tested for the kaempferol derivatives. For the derivative of the glycosylated paepalantina, the detection limit (25.54 μ g.mL - 1 ) and quantization limit (77.39 μ g.mL - 1 ) were observed. The content of substances found in the met hanolic extract of the capitula were 2.39 % ( Pa1 ), 1.22 % ( Pa2 ), 2.52 % ( Pa3 ) and 8.38 % ( Pa4 ) . The total phenols content obtained was 126.41 m g. g - 1 in the extract of the capitulae and the content of the total flavonoid founded were 122.15 mg.g - 1. At the same time we evaluated the... / Mestre
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