Estudio fitoquímico parcial de Piper bogotense y evaluación de actividad antibacteriana frente a Pseudomonas aeruginosa

Abstract

The Infections are a worldwide public health problem that can have economic, social and health levels. Among the various types of infections, those associated with medical care stand out due to the frequency with which they occur and the mortality caused. These are generally attributed to gram negative bacteria, such as Pseudomonas aeruginosa, characterized by being pathogenic and opportunistic that inhabits hospital environments, making them potentially dangerous environments for patients with compromised immune systems due to resistance to commonly used antibiotics. The bacterium is characterized by having a communication system called Quorum Sensing, which allows generating mechanisms of increasing resistance to antibiotics. Added to this is the lack of effective control methods, which makes it necessary to search for new effective and safe antibacterial agents, plants being a possible solution mainly due to the great diversity of molecular structures found, their various biological activities and few presenting studies. Colombia has a great diversity of plant species, many of them without studies, making them interesting and the target of research work, the genus Piper being one of the most representative. Our research team interested in this topic has carried out investigations, evaluating the antibacterial potential of 28 extracts of various species of the genus, by the direct bioautography method against strains of the microorganism, resulting as one of the most active P. bogotense. For this reason, the objective of contributing to the search for antibacterial substances for the control of P. aeruginosa was established, based on the study of the chemical constituents of P. bogotense, highlighting the lack of biological studies. For this, the methodology included the collection, drying, milling and preparation of the ethanolic extract of the aerial part of P. bogotense. Subsequently, the extract was fractionated by liquid chromatography under vacuum and the extract and the resulting fractions were determined for their effect on P. aeruginosa by the direct bioautography method. The fraction with the highest antibacterial potential was subjected to purification using different chromatographic techniques to isolate and identify some of the major constituents. The phytochemical study carried out allowed the isolation and identification of eight compounds: two prenylated benzoic acid derivatives (4-methoxy-3-farnesylbenzoic acid C-1 and 4-hydroxy-3-farnesylbenzoic acid C-2), both reported for the first time for the species, a hydroquinone (2-farnesylhydroquinone C-3) and five sesquiterpenes (α-curcumene C-4, β-bisabolene C-5, Cis-calamenene C-6, caryophyllene oxide C-7 and Cadalene C-8) , first reported for the species. To the isolated and identified compounds, susceptibility and anti-QS activity tests were performed, highlighting the potential of C-2 with the ability to inhibit the growth of P. aeruginosa by 46.4% and anti-QS activity by 93.2%, being a potential alternative for the control of this bacterium.