Lychnophoric acid from Lychnophora pinaster: a complete and unequivocal assignment by NMR spectroscopy

Abstract

Abstract:The investigation of the hexane extract from aerial parts of Lychnophora pinaster provided, besides others substances, the E-isomer of lychnophoric acid, a sesquiterpene derivative previously isolated from L. affinis.

Caracterização morfológica, perfil químico, atividade biológica e conservação in situ do gênero Lychnophora Mart. (Asteraceae: Vernonieae: Lychnophorinae), Brasil

“…Estudos realizados com a espécie comprovam que a mesma contém substâncias que se mostram ativas contra o Tripanosoma cruzi, agente causador da Doença de Chagas. Como exemplo, pode-se citar o estudo realizado por Silveira et al (2005b), que, utilizando extrato aquoso liofilizado (LAE) da parte aérea da planta (113,62 μg/mL), verificaram a eliminação de 100% das cepas de T. cruzi presentes em amostras de sangue de ratos albinos infectados. Silveira et al (2005a) em um estudo de Ressonância Magnética Nuclear de Hidrogênio e Carbono-13 (RMN de 1 H e 13 C) com extrato da parte aérea da planta verificaram a presença de um derivado de cariofileno, o ácido lychnophoico, um isômero do ácido lychnophorico (Figura 2).…”

Comparative analysis of the trypanocidal activity and chemical properties of E-lychnophoric acid and its derivatives using theoretical calculations

“…NMR spectra (400 MHz) were measured using a Bruker AM-400, and TMS as internal standard. E-Lychnophoric acid (1), used as a raw material, was obtained as previously described [12]. IR (KBr, cm -1 ) ν: 2400-2300, 2900, 2800, 1680, 1600, 1400, 1255 and 855; 1 H NMR (400 MHz, CDCl 3 ) δ H : 6.99 (t, J=7.9 Hz, H-5), 4.92 (d, J=0.9 Hz, H-14a), 4.80 (d, J=0.9 Hz, H-14b), 2.50 (dd, J=9.5 and 2.7 Hz, H-7a), 2.47 (dd, J=3.9 and 2.7 Hz, H-3a), 2.45 (ddd, J=5.4, 1.3 and 0.7 Hz, H-9), 2.42 (ddd, J=9.5, 2.0 and 1.3 Hz, H-7b), 2.36 (d, J=2.7 Hz, H-3b), 2.33 (ddd, J=5.4, 1.3 and 0.9 Hz, H-1), 2.27 (dd, J=7.9 and 2.0 Hz, H-6a), 1.80 (ddd, J=7.9 and 2.7 and 1.3 Hz, H-6b), 1.73 (dd, J=9.5 and 1.3 Hz, H-10a), 1.65 (ddd, J=15.5, 2.7 and 1.3 Hz, H-2a), 1.55 (dd, J=9.5 and 0.7 Hz, H-10b), 1.45 (ddd, J=15.5, 3.9 and 0.9 Hz, H-2b), 1.00 (s, H-13) and 0.98 (s, H-12); 13 E-Lychnophoric acid methyl ester 2 was obtained by the esterification of acid 1 with an acetic anhydride/pyridine mixture [13].…”

“…Lychnophora species extracts in water, ethanol or "cachaça" (sugar cane spirit) are used in Brazilian folk medicine as analgesic, antiinflammatory and anti-rheumatism remedies [9]. From one of them, Lychnophora pinaster Mart, Elychnophoric acid, bicycle[7.2.0]undec-4-en-4carboxylic acid-11,11-dimethyl-8-metilen-[1R-(1R*,4E,9S*)] 1 (Figure 1) was isolated [10][11][12]. This compound was submitted to anti-HIV, cytotoxicity by brine shrimp lethality model, and anti-tumor activity tests without major results [10].…”

Comparative analysis of the trypanocidal activity and chemical properties of E-lychnophoric acid and its derivatives using theoretical calculations

“…E-Lychnophoric acid (1), used as a raw material, was obtained as previously described [12]. IR (KBr, cm -1 ) ν: 2400-2300, 2900, 2800, 1680, 1600, 1400, 1255 and 855; 1 H NMR (400 MHz, CDCl 3 ) δ H : 6.99 (t, J=7.9 Hz, H-5), 4.92 (d, J=0.9 Hz, H-14a), 4.80 (d, J=0.9 Hz, H-14b), 2.50 (dd, J=9.5 and 2.7 Hz, H-7a), 2.47 (dd, J=3.9 and 2.7 Hz, H-3a), 2.45 (ddd, J=5.4, 1.3 and 0.7 Hz, H-9), 2.42 (ddd, J=9.5, 2.0 and 1.3 Hz, H-7b), 2.36 (d, J=2.7 Hz, H-3b), 2.33 (ddd, J=5.4, 1.3 and 0.9 Hz, H-1), 2.27 (dd, J=7.9 and 2.0 Hz, H-6a), 1.80 (ddd, J=7.9 and 2.7 and 1.3 Hz, H-6b), 1.73 (dd, J=9.5 and 1.3 Hz, H-10a), 1.65 (ddd, J=15.5, 2.7 and 1.3 Hz, H-2a), 1.55 (dd, J=9.5 and 0.7 Hz, H-10b), 1.45 (ddd, J=15.5, 3.9 and 0.9 Hz, H-2b), 1.00 (s, H-13) and 0.98 (s, H-12); 13 E-Lychnophoric acid methyl ester 2 was obtained by the esterification of acid 1 with an acetic anhydride/pyridine mixture [13].…”