SciELO - Scientific Electronic Library Online

 
vol.30 issue3Synthesis of hydroxyapatite by sol-gel method using alternative precursors: calcium nitrate and phosphoric acidDetermination of Hg in water by CVAAS using 2-aminothiazole modified silica author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Eclética Química

Print version ISSN 0100-4670

Abstract

ALCANTARA, A. F. C. et al. Comparative analysis of the trypanocidal activity and chemical properties of E-lychnophoric acid and its derivatives using theoretical calculations. Eclet. Quím. [online]. 2005, vol.30, n.3, pp. 37-45. ISSN 0100-4670.  http://dx.doi.org/10.1590/S0100-46702005000300005.

E-Lychnophoric acid 1, its derivative ester 2 and alcohol 3 killed 100% of trypomastigote blood forms of Trypanosoma cruzi at the concentrations of 13.86, 5.68, and 6.48 µg/mL, respectively. Conformational distribution calculations (AM1) of 1, 2 and 3 gave minimum energies for the conformers a, b, c, and d, which differ from each other only in the cyclononene ring geometry. Calculations (DFT/BLYP/6-31G*) of geometry optimization and chemical properties were performed for conformers of 1, 2, and 3. The theoretical results were numerically compared to the trypanocidal activity. Calculated values of atomic charge, orbital population, and vibrational frequencies showed that the C-4-C-5 p-endocyclic bond does not affect the trypanocidal activity of the studied compounds. Nevertheless, the structure of the group at C-4 strongly influences the activity. However, the theoretical results indicated that the intra-ring (C-1 and C-9) and p-exocycle (C-8 and C-14) carbons of caryophyllene-type structures promote the trypanocidal activity of these compounds.

Keywords : Lychnophora pinaster; DFT calculation; caryophyllene derivatives; trypanocidal activity; Trypanosoma cruzi.

        · abstract in Portuguese     · text in English     · pdf in English