Anti-bacterial action of extracts and fractions from Siparuna sessiliflora Kunth A. DC (limoncillo)

Introduction: Siparuna sessiliflora Kunth A. DC. is a plant species popularly known in Colombia as «limoncillo» and used by several indigenous communities for treating different health disorders. Despite the many records of its ethnobotanical uses, this species has been poorly studied from a phytochemical or biological standpoint. Objectives: to evaluate the antibacterial activity of the extracts and fractions obtained from Siparuna sessiliflora's leaves against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Methods: the plant material was extracted by cold maceration with petroleum ether and 96% ethanol. Those extracts were fractionated by chromatographic methods and liquid-liquid partitioning; additionally, its antibacterial activity was assessed by gel diffusion. Subsequently, there were identified the main bioactive compounds by gas chromatography-mass spectrometry. Results: it was found that the alkaloidal fractions Alk 1 and Alk 2 were active against B. subtilis, S. aureus and E. coli. Additionally, the subfraction Alk 2A was the most active against B. subtilis. Isoquinoline alkaloids and a cinnamic acid derivative were identified as possible compounds responsible for bioactivity. Conclusions: the antibacterial activity of S. sessiliflora against Gram positive and Gram negative bacteria was reported, so the new knowledge about its phytochemistry endorses its traditional use in the treatment of infections.