Activity of a compound isolated from Senna villosa against Trypanosoma cruzi

Previously we reported that chloroform extract of S. villosa (Miller) Irwin & Barneby possess activity against epimastigotes and trypomastigotes of T. cruzi [1]. From this extract was isolated a compound, which was identified as 4-hydroxymethylen-2-pentaeiconanone mp 76–77°C, (KBr/cm): 3451, 2919, 2850, 1735. ¹HNMR (400MHz CDCl₃) δ (ppm): 0.88(t,3H), 1.25(m,38H), 1.57(s,3H), 1.61(m,3H), 2.29(m,2H), 4.05(m,2H). ¹³CNMR: 14.0(CH₃), 22.7(CH₂), 25.0(CH₂), 25.9(CH₂), 28.6(CH₂), 29.4(CH), 29.5(CH₃), 29.6(CH₂), 31.0(CH₂), 34.3(CH₂), 64.3(CH₂), 173.6(C=O), EIMS (m/z): 396(1), 97(54), 83(60), 57(100). Analysis combustion calcd for C₂₆, H₅₂O₂, C 78.35%, H 13.44%, O 8.21%. Activity was assayed on epimatigotes and trypomastigotes of T. cruzi strain Y isolated from human, cultured in liver infusion tryptose medium supplemented with 10% of heat-inactived fetal calf serum and cultured at 28°C. 1.65, 3.3 and 6.6µg/mL concentration of this compound was tested. Gentian violet (17.5mg/mL) was used as positive control. Parasites were counted daily for 10 days. At concentration of 1.65µg/mL the growth inhibition of trypomastigotes was 60%, with 3.3µg/mL 72% and with 6.6µg/mL was 82%, similar results were obtained with epimatigotes. The activity was doses-dependent in both forms of parasite. The susceptibility of parasite to the compound is similar to that observed with gentian violet.

Reference: 1. Guzmán, E. et al. (2004), Pharm. Biol. 42: 1–4.