Jacaranone derived glucosidic esters from Jacaranda glabra

The genus Jacaranda (Bignoniaceae) native to the New World, but also widely cultivated in the Old World, contains 49 species. Recently, a review of the ethnobotanical and pharmacological uses of Jacaranda species has pointed out interesting biological and chemical perspectives with regard to skin illnesses and protozoa related diseases [1]. In our current project on the validation of anti-protozoal activity of plants traditionally used in Ecuador, the dichloromethane extract of the leaves of Jacaranda glabra (DC.) Bureau & Schumann has shown promising activity against Plasmodium falciparum K1 strain. Activity guided isolation yielded 4 novel glucosidic esters (1–4) containing quinolacetic acid (R₁ ), phenylacetic acid (R₂ ) and para-hydroxy-phenylacetic acid (R₃ ) moieties. The compounds identified by NMR experiments and MS techniques exhibited activity against Pl. f. K1 strain (IC₅₀ 1: 1.1, 2: 0.6, 3: 0.6 and 4 0.5µg/mL) and low cytotoxicity on L-6 cells, except for compound 1 (IC₅₀ 1: 2.6, 2: >90, 3: 87 and 4 85µg/mL). In addition, 4 ethnobotanical preparations were found active. Similar structures have been previously reported in literature [2,3].

Acknowledgements: This research is part of a dissertation funded by the Austrian Exchange Service (ÖAD).

References: [1] Gachet, M.S. and Schühly, W. (2009)J. Ethnopharmacol. 121:14–27.

[2] Tian, X.Y. et al. (2006)J. Asian Nat. Prod. Res. 8:125–132.

[3] Ming, D.S. et al. (1998)J. Nat. Prod. 61:377–379.