Solanum campaniforme: constituintes químicos, estudo de fragmentação e desreplicação por espectrometria de massas com ionização por electrospray (IES-EM/EM)

Abstract

This work describes the phytochemical investigation of Solanum campaniforme (Solanaceae), aiming the isolation and structural elucidation of new bioactive chemical constituents, as well as the study of their fragmentation pattern under electrospray ionization tandem mass spectrometry (ESI-MS/MS) of the isolated alkaloids. The chemical investigation performed with the ethanol extract from leaves of this species by chromatographic methods, including HPLC (reverse phase), resulted in the isolation and identification of nineteen compounds, being four of them phenol derivatives: caffeic acid (SC-1), caffeic acid ethyl ester (SC-2), kaempferol-3-rutinoside (SC-3) and tyramine (SC-4), and fifteen steroidal alkaloids: 22,23-epoxy-solanida-1,4,9-trien-3-one (SC-5), 22,23-epoxy-solanida-1,4-dien-3-one, (SC-6), 3,9-dihydroxy-22,23-epoxy-9(10)-seco-solanida-1,3,5(10)-triene (SC-7), 12-acetoxyl-(25S)-22N-spirosol-4-en-3-one (SC-8), (25S)-22N-spirosol-1,4-dien-3-one (SC-9), (25S)-22-N-spirosol-4-en-3-one (SC-10), 22,23-epoxy-solanida-1,4-dien-3-one (SC-11), 22,23-epoxy-10-epi-solanida-1,4,9-trien-3-one (SC-12), 12-hydroxy-(25S)-22N-spirosol-4-en-3-one (SC-13), 22,23-epoxy-solanida-4-en-3-one (SC-14) and 22,23-epoxy-solanida-4-en-3-one (SC-15), (E)-N-[8’(4-hydroxyphenyl)ethyl]-22,23-epoxy-solanida-1,4,9-trien-3-imine (SC-16), (E)-N-[8’(4-hydroxyphenyl)ethyl]-22,23-epoxy-solanida-1,4-dien-3-imine (SC-17), (Z)-N-[8’(4-hydroxyphenyl)ethyl]-22,23-epoxy-solanida-1,4,9-trien-3-imine (SC-18) and (Z)-N-[8’(4-hydroxyphenyl)ethyl]-22,23-epoxy-solanida-1,4-dien-3-imine (SC-19). Except the alkaloids SC-9 and SC-10, which are being reported as natural products for the first time, all others are unknowns. The structure of all isolated compounds were elucidated by spectral) methods (IR, HR-ESI-MS, 1H and 13C NMR 1D and 2D and by comparison with literature data. The fragmentation pattern of the alkaloids was established based on MS/MS experiments and the data were used for the dereplication these compounds present in the crude ethanol extract from leaves of S. campaniforme. The cytotoxic potencial of the main alkaloids (SC-5 and SC-7) was evaluated against the human tumor cell lines (HCT8, MDA-MB-435, HL6 and SF295), however, no one showed any activity. The antiophidic properties of the same compounds were also investigated against Bothrops pauloensis venom, showing anti-myotoxic, anti-hemorrhagic and anti-necrosis effects. In addition, was evaluated the effect of tyramine on the metabolism of animals with dyslipidemia and obesity, which exhibited therapeutic effect associated to reduction of the cholesterol levels