Industrial scale isolation, structural and spectroscopic characterization of epiisopiloturine from Pilocarpus microphyllus stapf leaves: a promising alkaloid against schistosomiasis

This paper presents an industrial scale process for extraction, purification, and isolation of epiisopiloturine (EPI) (2(3H)- Furanone,dihydro-3-(hydroxyphenylmethyl)-4-[(1-methyl-1H-imidazol-4-yl)methyl]-, [3S-[3a(R*),4b]]), which is an alkaloid from jaborandi leaves (Pilocarpus microphyllus Stapf). Additionally for the first time a set of structural and spectroscopic techniques were used to characterize this alkaloid. EPI has shown schistomicidal activity against adults and young forms, as well as the reduction of the egg laying adult worms and low toxicity to mammalian cells (in vitro). At first, the extraction of EPI was done with toluene and methylene chloride to obtain a solution that was alkalinized with ammonium carbonate. The remaining solution was treated in sequence by acidification, filtration and alkalinization. These industrial procedures are necessary in order to remove impurities and subsequent application of the high performance liquid chromatography (HPLC). The HPLC was employed also to remove other alkaloids, to obtain EPI purity higher than 98%. The viability of the method was confirmed through HPLC and electrospray mass spectrometry, that yielded a pseudo molecular ion of m/z equal to 287.1 Da. EPI structure was characterized by single crystal X-ray diffraction (XRD), 1H and 13C nuclear magnetic resonance (NMR) in deuterated methanol/chloroform solution, vibrational spectroscopy and mass coupled thermal analyses. EPI molecule presents a parallel alignment of the benzene and the methyl imidazol ring separated by an interplanar spacing of 3.758 Å indicating a π-π bond interaction. The imidazole alkaloid melts at 225°C and decomposes above 230°C under air. EPI structure was used in theoretical Density Functional Theory calculations, considering the single crystal XRD data in order to simulate the NMR, infrared and Raman spectra of the molecule, and performs the signals attribution

Disciplina Escolar e Gestão de Sala de Aula no Campo Educacional Brasileiro

Resumo: O texto tem por objetivo analisar as questões relativas à disciplina escolar e à gestão de sala de aula como campo de pesquisa e questão profissional. Inicia com uma breve retomada da tradição norte-americana nas pesquisas sobre o tema. Na segunda parte, analiso as condições, potenciais e limites associados a tomar a disciplina escolar e gestão de sala de aula como campo de pesquisa no Brasil usando como indicadores os trabalhos publicados nos encontros anuais da ANPEd entre 2007 e 2011 e no seminário Indisciplina na Escola Contemporânea. A terceira parte é dedicada à relação entre gestão de sala de aula, enquanto saber profissional, e a formação de professores no Brasil. A última parte é dedicada às considerações finais

Scheme of all necessary steps in obtaining Epiisopiloturine with >98% purity from Jaborandi leaves.

<p>Scheme of all necessary steps in obtaining Epiisopiloturine with >98% purity from Jaborandi leaves.</p

Mass spectrum obtained from ESI+/Ion Trap.

<p>(A) free EPI with a pseudo molecular ion m/z 287.1 Da [M+H]⁺, (B) MS² with characteristic fragment at m/z 269.1 Da [M – H₂O + H]⁺, (C) MS³ with fragments at m/z 251.0 Da [M – 2H₂O + H⁺] and 168.06 Da with proposed chemical structure.</p

Analytical HPLC used LiChrospher 60 RP column and eluted with potassium phosphate

<p>. (A) Standard EPI (20 µg/mL), (B) Standard pilocarpine (50 µg/mL), (C) “cultivated jaborandi leaves” solution, resulted from first extraction step, (D) “cultivated jaborandi acid” solution, obtained EPI under salt form, (E) Solution of “crude EPI” with some impurities as pilocarpine and other alkaloids, (F) last step of isolation showing EPI >98% purity.</p