Estudo da composição química e avaliação da atividade antimicrobiana de extratos das folhas de Piper arboreum e Piper aduncum

Abstract

The species Piper arboreum and P. aduncum, belonging to the Piperaceae family, are popularly known as "long pepper" and "monkey pepper", respectively. These Piper species are widely used in folk due to the substances present in bioactive extracts. Thus, in this work, leaf extractions of the species Piper mentioned with solvents of different polarities such as in hexane, ethanol and dichloromethane, followed by phytochemical prospection in Thin Layer Chromatography (TLC) with specific developers for the main classes of secondary metabolites. The antimicrobial activity of the extracts was tested against three species of fungi that cause candidiasis through the Minimum Inhibitory Concentration (MIC) and also for aerobic and anaerobic bacteria. The ethanolic extracts of P. arboreum (EE01) and P. aduncum (EE02), plus the dichloromethane extract for P. arboreum (ED01) were more active about the analyzed fungi, especially the fungus Candida tropicalis (MIC of 46.7; 187.5; 187.5 µg mL-1, respectively). However, for antibacterial activity, the species of P. arboreum presented a greater inhibition in hexane extraction (EH01), with excellent results against the two anaerobic bacteria and only one for aerobic bacteria, all with MIC values equal to 100 µg mL-1. The leaves of P. aduncum stood out in ethanol extraction (EE02), with greater inhibitions for anaerobic bacteria Porphyromonas gingivalis and Actinomyces naeslundii, both with MIC 50 µg mL-1 . The extracts were analyzed by high performance liquid chromatography coupled to the mass spectrometer (HPLC/EM) to identify bioactive compounds. Through the analysis, it was verified, among other compounds, the presence of the catechin flavonoid (m/z 289.0715) and aduncamide (m/z 318.1336), of the laurenobiolide sequisterenic lactone (m/z 291.1591), which are compounds with the potential to prevent oral microbial agents, such as cavities and periodontitis making these studied species promising in possible phytotherapeutic drugs.