887 resultados para 3D and 2D background modelling


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The antimicrobial properties of the hexane, hexane/EtOAc and methanol fractions of the fresh petioles of Sagittaria montevidensis ssp montevidensis (Alismataceae) were evaluated against fungi and Gram-negative and Gram-positive bacteria. A new abietatriene-type diterpenoid, 3β,7α-dihydroxi-abieta-8,11,13-triene and the known 3β-hydroxy-abieta-8,11,13-trien-7-one were isolated from the most active fraction tested and the structures of these compounds were elucidated by data including IR, EIMS, and 1D and 2D NMR spectra.

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The chemical investigation of the ethanol extracts of stems, roots and leaves of Lippia sidoides led to the isolation of: steroid β-sitosterol, naphthoquinone tecomaquinone, monoterpene carvacrol, flavonoid 4',5,7-trihydroxyflavanone (naringenin), 3',4',5,7-tetrahydroxyflavanone and 4',5,7-trihydroxy-6-methoxyflavone flavonoids mixture, and 3,4,4',6'-tetrahydroxydihydrochalcone-2'-O-β-D-glucopyranoside and 4,4',6'-trihydroxydihydrochalcone-2'-O- β-D-glucopyranoside dihydrochalcones mixture. Their structures were characterized on the basis of spectral data, mainly ¹H and 13C NMR (1D and 2D) and mass spectra. The ethanol extract and isolated compounds were evaluated for their antioxidative properties using the method of inhibition of free radical DPPH (2,2-diphenyl-1-picrylhydrazyl).

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The phytochemical investigation of a sample of propolis from Passa Quatro-Minas Gerais State, Brazil, where nine constituents were isolated: a mixture of α- and β-amyrin, lupeol, a mixture of flavonols ramnocitrin and eupalitin, acacetin, 3-prenyl-4-hydroxycinnamic acid, 3,5-diprenyl-4-hydroxycinnamic acid the new compound, the (E)-3-[4-(3-phenylpropanoiloxy)]-3,5-diprenil-cinnamic acid. The structures of the isolated compounds were characterized by 1D- and 2D-NMR experiments, MS and IR spectrometry, and comparison with data described in the literature.

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A new flavone named 3,4',5,6-tetramethoxy-[2'',3'':7,8]furanoflavone besides the known flavonoids (2S,3R,4S)-3,4,5,8-tetramethoxy-[2'',3'':6,7]-furanoflavan, 3,6-dimethoxy-2'',2''-dimethylcromene-[2'',3'':7,8] -flavone, 3,5,6-trimethoxy-[2'',3'':7,8]-furanoflavone, 2,4',4,5-tetramethoxy-[2'',3'':6,7]-furanodihydroaurone, (2R,3S,4S)-3,4,5,6-tetramethoxy-[2'',3'':7,8]-furanoflavan and 3',4'-methylenodioxy-5,6-dimethoxy-[2'',3'':7,8]-furanoflavone were isolated from the root barks of Lonchocarpus campestris. The complete ¹H and 13C NMR assignments of the new furan flavonoid was performed using 1D and 2D pulse sequences, including COSY, HMQC and HMBC experiments.

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Bioguided fractionation of Agelas cerebrum crude extract resulted in isolation of four bromopyrrole and four bromopyrrole aminoimidazole alkaloids, identified as 5-bromopyrrole-2-carboxylic acid (1), 4-bromopyrrole-2-carboxylic acid (2), 3,4-bromopyrrole-2-carboxylic acid (3), 4,5-bromopyrrole-2-carboxylic acid (4), oroidin (5), bromoageliferin (6), dibromoageliferin (7) and dibromosceptrin (8) on the basis of spectroscopic data analyses (UV, IR, HRMS, 1D and 2D NMR) and comparison with literature data. This is the first report of compounds 2 and 3 in a marine sponge belonging to the Agelas genus and the first evidence of the presence of 1 from a natural source.

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In my PhD dissertation, I have examined a group of people of Scandinavian origin received by Ospizio dei Convertendi. This group has been hitherto largely unknown to historical research. The Ospizio was an institute founded by the Oratorian Congregation in Rome in 1673 to provide religious instruction and material aid to both recent and aspirant converts to Roman Catholicism. My research traces the profile of converts and a typology of motives, examining different factors which influenced the conversion process. I show that the key factors were often of a social rather than a religious nature. Moreover, I have analyzed the hospice in the context of Counter-Reformation charity as well. In terms of numbers, the Scandinavians formed a somewhat marginal yet not insignificant group within the Roman hospice. Out of a total of 2203 guests received between 1673 and 1706, 4.6 % were Scandinavians: 74 Swedes (including Finland and Livonia) and 27 Danes (including Norway). They came from a rigorously Protestant region which reacted to Catholicism with severe legislative measures. Converts to Catholicism risked confiscation of their goods, expulsion or even capital punishment. Since both Sweden and Denmark were practically impenetrable to Catholicism at the time and clandestine missionary attempts often failed before they had even properly started, the Roman Catholic Church shifted its interest towards Northerners arriving in Rome, a preferred destination for young noblemen, artists and migrant craftsmen. The material related to Ospizio dei Convertendi, conserved in the Vatican archives, is a scarcely known yet unusually rich source, not only for the religious history of our continent, but also for social history and the study of migration in early modern Europe. It contains a wealth of information about members of the subordinate classes, of their travels and lives in Europe. The profile delineated in these documents is of individuals who had a wide range of different professions and different aspirations. These documents encompass a vast social spectrum that was highly mobile on a continent which by that time had become pluriconfessional. Therefore, these migrants faced the complex religious reality in their everyday life. The principal corpus of my research consists of two types of manuscript sources created for administrative and in a way also for apologetic purposes of the Roman Catholic Church. My starting point is the Primo registro generale of Ospizio dei Convertendi. This is a volume in which the following information about each guest was registered: name, nationality, city of origin, age, sex, profession, confession professed before converting, date of arrival, departure, abjuration and baptism. Typically, the convert was male, originating from Stockholm or Copenhagen, from 21 to 30 years of age. The biggest occupational groups in descending order were soldiers, noblemen, craftsmen and sailors. Thus the data reflects a multiform reality of interurban and long distance migration, ideals regarding the education of young noblemen and gentry as well as the need of European armies to hire foreign mercenaries in their various campaigns. Against this background the almost total absence of women is hardly surprising: there is only one woman in the material I have studied. The second main source, Nota degl’ospiti ricevuti e spese fatte per essi, sheds more light on the choices of the converts, their motivations and their lives outside Scandinavia before reaching Rome. This narrative material permits an analysis which completes but also goes far beyond the columns of the Institute’s general register. This material consists of reports written by Catholic priests based on an interview conducted upon each guest’s arrival. The material frequently includes information on what the converts would do following their departure from the Institute as well. These sources have a specific narrative form and contain short biographies, list reasons for converting and information about the journey from the North to the Mediterranean - a journey which in many cases took several years. Moreover, they show that certain unorthodox practices such as calling on the saints and pleading for help from them were not uncommon in the Protestant popular religion. The recording of information on conversions from Protestantism to Catholicism reflects both religious and social interest on the part of the receiving institute. The information obtained was used for the purposes of religious teaching, for finding adequate ways of inserting the convert into Italian society so that he could earn a living, and to find effective methods to convert others with a similar cultural and geographical background. The stories recorded were based on interviews with the newly-arrived, information obtained from a travel companion or fellow countrymen, or from written documents the aspirant converts carried with them. These sources illustrate, although sometimes in rather simplified ways, the circumstances and motivations which were relevant to the choice of changing one’s confession. In addition, I have examined petitions addressed to the hospice and other Roman authorities in order to get financial aid. These petitions were written by Italian scrittori, and they contain certain conventions and topoi of presenting the conversion with the purpose of improving the chances of obtaining financial aid. It is through these filters, which may seem initially almost invisible, that the remote voice of the converts reaches us. The results of the analysis are particularly interesting because they disagree with some of the principal conclusions of previous work on the subject. First, earlier research has focused almost exclusively on the conversions of noblemen, and has argued, second, that the Queen Christina of Sweden was the driving force behind their change of confession. The sources examined for this dissertation present a profile of long-distance migrants, many of them members of the subordinate classes, who were looking for ways to make their living in Europe. These people had in many cases left their country of origin several years earlier and not for religious reasons, so, crucially, we are not dealing with confessional migration in these cases. Rather, conversion was a complex process, intricately tied up with strategies of survival, integration and upward social mobility. At the same time, while these components are significant on their own right, they do not necessarily point to the absence of motivations of a more clearly religious nature.

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The phytochemical investigation of the stem bark and leaves of G. elliptica provided a mixture of the norisoprenoids blumenol B and 6-epiblumenol B along with the triterpenes friedelin, as the major constituent, friedelanol, ursa-9(11),12-dien-3-ol, a-amyrin, β-amyrin, morentenol, epifriedelanol, as well as the sesquiterpenes trans-caryophyllene, α-humulene, ethyl hydnocarpate and other fatty acid esters. The identification of the compounds was performed on basis of spectrometric methods such as GC-MS, IR, MS and 1D and 2D NMR. Stem bark extracts showed significant leishmanicidal activity against promastigote forms of Leishmania braziliensis, with the best results for the chloroform extract.

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Two new sesquiterpenes 6α-ethoxyeudesm-4(15)-en-1β-ol (1) and (7R*)-5-epi-opposit-4(15)-ene-1β,7-diol (7) were isolated from the seeds of a specimen of Guarea guidonia (Meliaceae). Five other known sesquiterpenes, eudesm-4(15)-ene-1β,6α-diol (2), 5-epi-eudesm-4(15)-ene-1β,6β-diol (3), eudesm-4(15)-ene-1β,5α-diol (4), eudesm-4(15),7-dien-1β-ol (5) and (7R*)-opposit-4(15)-ene-1β,7-diol (6), were also isolated in this work. Their structures were determined on the basis of spectral data (MS, IR, and NMR-1D and 2D) and subsequent comparisons with the literature. The substances 3, 4 and 6 are reported for the first time in Meliaceae and 5 for the first time in the genus Guarea.

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A new salicylic acid derivative, pentacosanyl salicylate, was isolated from the leaves of the plant toxic to cattle, Riedeliella graciliflora, in addition to a digalactosyldiacylglycerol (DGDG), 1,2-di-O-α-linolenoyl-3-O-α-D-galactopyranosyl-(1→6)-β-D-galactopyranosyl-glycerol, kaempferol-3-O-β-D-glucopyranoside, kaempferol-3-O-α-L-rhamnopyranoside, quercetin-3-O-α-L-rhamnopyranoside, rutin, (+)-catechin and the dimer (+)-catechin-(4β-8)-catechin, glutinol, squalene, β-sitosterol, stigmasterol, phytol, β-carotene, α-tocopherol and ficaprenol-12. Their structures were determined using spectral techniques (MS, IR, and NMR-1D and 2D) and based on literature data.

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The chemical investigation of the ethanolic extract from leaves of Croton pedicellatus yielded the bis-nor-sesquiterpenes blumenol A and blumenol A glucoside, along with the flavonoids: tiliroside, 6"-O-p-coumaroyl-β-galactopyranosyl- kaempferol, 6"-O-p-coumaroyl-β-glucopyranosyl-3"-methoxy- kaempferol, kaempferol, 3-glucopyranosyl-quercetin and alpinumisoflavone, as well as 4-hydroxy-3,5-dimethoxybenzoic acid. The identification of all isolated compounds was performed by spectrometric methods, including HR-ESI-MS, 1D and 2D NMR experiments, and by comparison with previously-described physical and spectral data.

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Six new eremophilane sesquiterpenes, (rel)-4β,5β,7β-eremophil-9-en-12-oic acid (1), (rel)-4β,5β,7β-eremophil-1(10)-en-12-oic acid (2), (rel)-4β,5β,7β-eremophil-1(10)-en-2-oxo-12-oic acid (3), (rel)-4β,5β,7β-eremophil-9-en-12,8α-olide (4), (rel)-4β,5β,7β-eremophil-9-en-12,8β-olide (5) and (rel)-4β,5β,7β-eremophil-9α,10α-epoxy-12-oic acid (6), were isolated from the leaves of a specimen of Ocotea lancifolia (Lauraceae). Two other known sesquiterpenes, 4β,5β,7β-eremophil-11-en- 10α-ol (7) reported for the first time in the genus Ocotea, and the aromadendrene sesquiterpene, spathulenol (8), were also isolated. Their structures were determined on the basis of spectral data (MS, IR, UV and NMR-1D and 2D) and subsequent comparisons with the literature.

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In addition to β-sitosterol, stigmasterol, phaeophitin A, luteolin, kaempferol, quercetin, (+)-catechin, quercetin-3-O-α-L-rhamnopyranoside, rutin, and p-hydroxy-benzoic acid, six known sesquiterpenes, namely (rel)-2β,6β-epoxy-5β-hydroxy-isodaucane, oplopanone, 1β,6α-dihydroxy-4(15)-eudesmene, caryophyllene oxide, α-cadinol, and spathulenol, were isolated from the leaves of Pterodon pubescens (Leguminosae) growing in the Cerrado of Mato Grosso do Sul, Brazil. The (rel)-2β,6β-epoxy-5β-hydroxy-isodaucane corresponds to the correct structure of homalomenol D. The sesquiterpene oplopanone, which bears a modified cadinane skeleton, is being reported for the first time in this genus. The structures of the compounds were determined on the basis of spectral data (MS, IR, and NMR-1D and 2D) and subsequent comparison with data reported in the literature.

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This contribution introduces a brief discussion about the properties and applications of the rare earth elements, with a focus on their current status in Brazil. The general chemical properties, main applications and historical background of the chemistry of these elements are presented, and special attention is devoted to the development of the exploitation and both academic and industrial activities involving rare earths in Brazil. A discussion of the current world scenario ensues and some perspectives regarding the prospection, market and government policy concerning the rare earth elements in Brazil are given.

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Eight compounds, including terpenoids (jatrophone, hydroxyjatrophone, 6-hydroxycyperene, cabraleadiol monoacetyl, and cabraleadiol) and coumarins (fraxetin, fraxidin, and isofraxidin), were isolated from Jatropha ribifolia (Euphorbiaceae). Their structures were established by 1D and 2D NMR (COSY, HSQC, and HMBC) spectra, HRESIMS and comparison with published data.

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Phytochemical investigations of the stem bark, leaves and twigs of Guatteria citriodora resulted in the isolation of eight alkaloids: liriodenine, lysicamine, O-methylmoschatoline, 3-methoxyoxoputerine, palmatine, 3-methoxyguadiscidine, guattescidine and oxoputerine. The structures of the isolated substances were established by extensive spectroscopic techniques (1D and 2D NMR) and mass spectrometry (MS), as well as by comparison with data reported in the literature. The in vitro antimalarial activity of the alkaloidal fractions of the leaves and twigs against Plasmodium falciparum FCR3 showed significant results, with IC50 = 1.07 and 0.33 mg mL-1, respectively. The alkaloidal fraction of the leaves showed moderate activity against Enterococcus faecalis, with IC50 = 125.0 mg mL-1. Antiplasmodial and antibacterial activities are attributed to alkaloidal constituents.