Isolation and Structural Characterization of Two New Furanoditerpenes from Pterodon emarginatus (Fabaceae)

Abstract

A furanoditerpene-enriched fraction was obtained from the fruits of Pterodon emarginatus and submitted to semipreparative high performance liquid chromatography (HPLC). Two new furanoditerpenes, 6α,19β-diacetoxy-7β,14β-dihydroxyvouacapan and 6α-acetoxy-7β,14β-dihydroxyvouacapan, in addition to the known compound methyl 6α-acetoxy-7β-hydroxyvouacapan-17β-oate were obtained. Compound structures were determined by 1D and 2D nuclear magnetic resonance (NMR) experiments and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS). The major compound methyl 6α-acetoxy-7β-hydroxyvouacapan-17β-oate was evaluated against promastigote forms of Leishmania amazonensis and L. braziliensis, presenting the concentration which causes lysis on 50% of parasites IC 50 < 30 µg mL -1 .

The Potential of Vouacapanes from Pterodon Emarginatus Vogel against COVID-19 Cytokine Storm

“…The oleoresin was extracted by cold pressing in a continuous mini-press (MPE-40 ECIRTEC, Bauru, São Paulo, Brazil), as previously described, 30 with a yield of 30% weight. The oleoresin (OR) was stored at -20°C until analysis.…”

“…The isolation of vouacapanes 6α,19β-diacetoxy-7β,14β-dihydroxyvouacapan (V1), 6α-acetoxy-7β,14β-dihydroxyvouacapan (V2) and 6α-acetoxy-7β-hydroxyvouacapan-17β-oate (V3), as well as the structural elucidation, were also described in previous work. 30 , 32 For all in vitro evaluations, the concentration used was 7.5 µg/mL (oleoresin), 19 µg/mL (V1), 13.8 µg/mL (V2) and 4 µg/mL (V3), defined according to the Cell Viability 90% concentration (CV 90 ) of each evaluated substance, determined by MTT cytotoxicity assay. 37 …”

“…Isoflavones and diterpenes (vouacapane-type) are the main components of oleoresin. [28][29][30][31][32][33][34] Vouacapane diterpenoids are low-tomedium polarity secondary metabolites. Studies suggested the vouacapane skeleton as the main pharmacophore, supported by pharmacological investigations of isolated compounds, as well as P. emarginatus oleoresin-derived vouacapane diterpenoids.…”

Avaliação in vitro das atividades antimicrobiana e anti-inflamatória de vouacapanos de Pterodon emarginatus Vogel (FABACEAE)

“…Além disso, as várias etapas envolvidas na purificação por cromatografia em coluna podem favorecer a ocorrência de reações químicas envolvendo os metabólitos secundários, resultando na formação de artefatos (PIZZOLATTI et al, 2002). Oliveira et al, (2017a) desenvolveram um método alternativo, simples e eficaz para o isolamento de voaucapanos de P. emarginatus por cromatografia líquida de alta eficiência semi-preparativa (CLAE).…”

“…A principal desvantagem desta técnica é a menor sensibilidade na análise de amostras em baixas concentrações, principalmente no caso da RMN de 13 C. Os espectros de RMN de 1 H e RMN de 13 C dos vouacapanos são caracterizados pelos sinais do anel furânico. O espectro de RMN de 1 H mostra os sinais dos hidrogênios furânicos em δH 6,4 (1H, d, Ј=1,9 Hz, H15) e δH 7,2 (1H, d, Ј=1,9 Hz, H16) e o espectro de RMN de 13 C mostra os sinais do anel furânico em δC 148,2 (C-12), 141,9 (C-16), 123,9 (C-13), e 107,2 (C-15) (HURTADO et al, 2013;SPINDOLA et al, 2009;OLIVEIRA et al, 2017a).…”