Identificação dos inibidores de acetilcolinesterase em Tetrapterys mucronata Cav. (Malpighiaceae) e comparação quali e quantitativa dos derivados triptamícos presentes na espécie em estudo e Ayahuasca

• Autor(a) principal: Queiroz, Marcos Marçal Ferreira [UNESP]
• Data de Publicação: 2013
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/108495
• topic: Quimica organica; Produtos naturais; Alcalóides; Cromatografia líquida de alta eficiência

The present work aims at seeking compounds that inhibit in vitro the enzyme acetylcholinesterase (AChE), and might be useful for the treatment of chronic neuro-degenerative diseases such as Alzheimer's. In this context the species Tetrapterys mucronata Cav. (Malpighiaceae) was selected from NuBBE’s bench of extract to be the focus of this work, due to the positive result for the in vitro inhibition of AChE conducted prior to this study. In the literature this species is also reported as a species used a lesser extent in the preparation of Ayahuasca. Thus, it was performed the phytochemical analysis of EtOH and aqueous extracts of T. mucronata. After analysis by HPLC-DAD of these extracts, was observed the presence of polymeric compunds (tannins). Liquid-Liquid Extraction (LLE) and Solid Phase Extraction (SPE) using polyamide as stationary phase were used to remove these interferents. The tanin free fraction (P6) was analyzed by HPLC-DAD-MS and UPLC-TOF-MS techniques in order to identified chemical constituents present in this fraction which had been previosly described in other species of Malpighiaceae family. This methodology led to the identification of catechin. As almost all the compounds present in the fraction could not be identified by the hyphenated techniques mentioned above, the P6 fraction was subjected to large-scale purification steps using MPLC-UV. The fractions obtained by this procedure were analyzed and as results were thus idintified 17 compounds, 5 of them new natural products: two alkaloids, 3-(3-(2-aminoethyl)-5-hydroxy-1H-indol-2-yl)-3-(1H-indol-3-yl)propane-1,2-diol (6) and 3-(3-(2-N,N-dimethyl-aminoethyl)-5-hydroxy-1H-indol-2-yl)-3-(1H-indol-3-yl)propane-1,2-diol (7); three phenanthrene derivatives 2,6-dihydroxy-9,10-dihydrofenanthrene (13), 2,6-dihydroxifenantrene (14) and 7-methyl-2,6-dihydroxifenantrene (17). 12 compounds were described for the first time in Malpighiaceae family: three tryptamine alkaloids...