Planta Med 2007; 73 - P_388
DOI: 10.1055/s-2007-987168

Antioxidant activity of polyphenolic compounds isolated from the bark of Trichilia catigua

FO Resende 1, E Rodrigues-Filho 2, F Petereit 3, JCP Mello 1
  • 1Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Estadual de Maringá, Av. Colombo, 5790, BR-87020–900, Maringá, Brazil
  • 2Departamento de Química, Universidade Federal de São Carlos, Rod. Washington Luiz, km 235, BR-13905–905, São Carlos, Brazil
  • 3Institut für Pharmazeutische Biologie und Phytochemie, Universität Münster, Hittorfstrasse 56, DE-48149, Germany

Trichilia catigua A. Juss. (Meliaceae) is popularly known as „catuaba“ and widely distributed in Brazil. Its bark is mainly used as stimulant, and has a high concentration of tannins. An ethyl acetate (EAF) and an aqueous (AQF) fraction were obtained from the crude extract (CE) of the „catuaba“ bark. The aim of this study was to evaluate the chemical composition and the antioxidant capacity of the CE and the EAF and AQF fractions. The total polyphenol content (TP) and total tannin content (TT), assessed by a pharmacopoeia test [1], were, PT=10.51±0.17 (RSD%=1.62) and TT=6.95±0.11 (RSD%=1.57). The TT was also evaluated in CE, EAF and AQF, giving values of 38.89±1.14 (RSD%=2.93); 69.36±0.49 (RSD%=0.70) and 33.80%±0.30 (RSD%=0.89), respectively. EAF was fractionated by column chromatography (Sephadex® LH-20) and 32 subfractions were obtained. The following compounds were isolated and identified: epicatechin (EP), procyanidins B2 (PB2), B4 (PB4) and C1 (PC1), cinchonains Ia (CIa), Ib (CIb), IIb (CIIb) and the new compounds cinchonain IIc (CIIc) and apocynin E (ApE) [2]. The in vitro antioxidant capacity of the CE, EAF and AQF and isolated compounds was evaluated using the DPPH· scavenging method and Fe3+-Fe2 reduction capacity. The values obtained by the DPPH· method for the extracts were IC50 (µg.ml-1): CE=5.44±0.18 (RSD%=3.31); EAF=3.85±0.09 (RSD%=2.35) and AQF=8.76±0.15 (RSD%=1.68); for the isolated compounds the values were IC50 (µM): EP=10.12±0.24 (RSD%=2.43); PB2=7.95±0.04 (RSD%=0.51); CIa=7.87±0.05 (RSD%=0,63); CIb=7.67±0.23 (RSD%=2.98); CIIb=5.05±0.05 (RSD%=0.98); CIIc=5.15±0.08 (RSD%=1.61) and PC1=4.08±0.01 (RSD%=0.28). Concerning the reduction capacity, the extracts had higher activity than Trolox, but lower than vitamin C. All the isolated compounds were more effective than vitamin C and Trolox; procyanidin C1 had the highest reduction capacity.

Acknowledgements: CNPq and CAPES, Brazil.

References: [1] Farmacopéia Brasileira. 4th. ed., 2002. p.176. 2. Resende, F.O. (2007) M.Sc. Thesis, Maringá, Brazil. 167p.