ABSTRACT Diarrhea is an infectious disease caused by bacterial, virus, or protozoan, and dengue is caused by virus, included among the neglected diseases in several underdeveloped and developing countries, with an urgent demand for new drugs. Considering the antidiarrheal potential of species of Maytenus genus, a phytochemical investigation followed by antibacterial activity test with extracts of branches and heartwood and bark of roots from Maytenus gonoclada were conducted. Moreover, due the frequency of isolation of lupeol from Maytenus genus the antiviral activity against Dengue virus and cytotoxicity of lupeol and its complex with β-cyclodextrins were also tested. The results indicated the bioactivity of ethyl acetate extract from branches and ethanol extract from heartwood of roots of M. gonoclada against diarrheagenic bacteria. The lupeol showed potent activity against Dengue virus and low cytotoxicity in LLC-MK2 cells, but its complex with β-cyclodextrin was inactive. Considering the importance of novel and selective antiviral drug candidates the results seem to be promising.

O heptapeptídeo BPP7a, p-Glu¹Asp²Gly³Pro4Ile5Pro6Pro7, forma um complexo de associação com a β-ciclodextrina na razão molar 1:1. O peptídeo e a sua forma complexa foram caracterizados por dicroísmo circular (CD) e titulação calorimétrica (ITC), as quais sugerem uma interação muito fraca entre a β-ciclodextrina e o peptídeo. Espectros de ressonância magnética nuclear (NMR) de ¹H a 400 e 600 MHz foram obtidos para o peptídeo puro e para o complexo com β-ciclodextrina e com estes foi possível a atribuição de todos os sinais de ressonância de hidrogênio do peptídeo. Experimentos de espectroscopia ordenada de difusão de alta resolução (HR-DOSY) foram conduzidos a fim de se confirmar a associação entre o BPP7a e a β-ciclodextrina, além de se verificar a quebra dos agregados moleculares do BPP7a devida a associação. A atividade anti-hipertensiva do complexo BPP7a/β-ciclodextrina foi avaliada em ratos naturalmente hipertensivos (SHR), mostrando resultados melhores do que os do peptídeo BPP7a puro

The BPP7a heptapeptide, p-Glu¹Asp²Gly³Pro4Ile5Pro6Pro7, forms an association complex with β-cyclodextrin in a 1:1 molar ratio. The peptide and its complex were characterized by circular dichroism (CD) and isothermal titration calorimetry (ITC), which showed a very weak interaction between the β-cyclodextrin and the peptide. Assignments of all hydrogen resonances of the peptide alone and as a complex were made using ¹H nuclear magnetic resonance (NMR) experiments at 400 and 600 MHz. High resolution diffusion ordered spectroscopy (HR-DOSY) experiments were carried out to establish the self-aggregation state of BPP7a. It was also shown that the β-cyclodextrin breaks the molecular clusters leading to complex formation. In addition, the anti-hypertensive activity of the BPP7a/β-cyclodextrin complex was evaluated in spontaneous hypertensive rats (SHR), showing increased activity compared to that of pure BPP7a.

Seis triterpenos pentacíclicos isolados dos galhos de Maytenus gonoclada (Celastraceae), incluindo todos os dados de RMN do novo composto 3-oxo-12α,29-diidroxifriedelano são aqui relatados. A estereoquímica do novo friedelano foi estabelecida por dados de RMN bidimensional (HSQC, HMBC e NOESY), e sua massa molecular confirmada por espectrometria de massas (ESI). Testes de atividade antimicrobiana usando método de difusão em disco e de macrodiluição foram realizados contra as bactérias Escherichia coli, Citrobacter freundii e Bacillus cereus, e contra o fungo Candida albicans. O triterpeno 3-oxo-12α-hidroxifriedelano mostrou resultado positivo contra C. albicans.

Six pentacyclic triterpenes were isolated from branches of Maytenus gonoclada (Celastraceae) and all NMR data of a new compound 3-oxo-12α,29-dihydroxyfriedelane are herein reported. The stereochemistry of the new friedelane was established by bidimensional NMR (HSQC, HMBC and NOESY) data, and its molecular weight confirmed by ESI mass spectrometry. Antimicrobial activity assays using the method of disk diffusion and macrodilution were carried out against the bacteria Escherichia coli, Citrobacter freundii, and Bacillus cereus, and against the fungi Candida albicans. The triterpene 3-oxo-12α-hydroxyfriedelane showed positive result against C. albicans.

Genistein:β-cyclodextrin complexes with high drug loading (19.22%) were prepared by freeze-drying and characterized by differential scanning calorimetry and hydrogen nuclear magnetic resonance spectroscopy. The spatial configuration of the complex was proposed by means of 2D-NOESY experiment combined with molecular modeling. According to the results obtained, the interaction of genistein with β -cyclodextrin in a 1:1 complex is supposed to occur mainly through the insertion of the guest A-ring in cyclodextrin cavity, without rule out the possibility of inclusion through the B-ring, as previously reported in the literature.