Preliminary phytochemical screening, total phenolic content and antibacterial activity of thirteen native species from Guayas province Ecuador

Phytochemical screening of ethanolic extracts of Acnistus arborescens (L.) Schltdl. (Solanaceae); Albizia multiflora (Kunth) Barneby & J.W. Grimes (Fabaceae); Capparidastrum petiolare (Kunth) Hutch. (Capparaceae); Colicodendron scabridum (Kunth) Seem. (Capparaceae); Gronovia scandens L. (Loasaceae); Gustavia angustifolia Benth. (Lecythidaceae); Piscidia carthagenensis Jacq. (Fabaceae); Psidium rostratum Mc Vaugh (Myrtaceae); Psidium guayaquilense Landrum & Cornejo (Myrtaceae); Psidium cf. rostratum Mc Vaugh (Myrtaceae); Salicornia fruticosa L. (Amaranthaceae); Simira ecuadorensis (Standl.) Steyerm. (Rubiaceae); Ruellia floribunda Hook. (Acanthaceae) were assayed. Alkaloids, tannins and terpenoids were the secondary metabolites most frequently found, while flavonoids, quinones, anthraquinones, steroids and saponins were present in less proportion. Folin-Ciocalteu method was used to quantify the total phenolic content in the ethanolic extracts using a calibration curve of gallic acid. The range between 941.97 ± 30.69 and 241.54 ± 15.54 GAE/mg dry extract, has been observed for Psidium guayaquilense and Acnistus arborescens, respectively. On the other hand, antibacterial activity of the ethanolic extracts was evaluated using the disk diffusion agar method against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Vibrio parahaemolyticus ATCC 17802. P. rostratum, P. guayaquilense, P. cf. rostratum, R. floribunda and S. ecuadorensis were the most active extracts against the bacterial assays with minimal inhibitory concentration (MIC) values ranging between 20 and 100 ppm. According to literature, it is most likely that this is the first report on phytochemical screening, total phenolic content and antibacterial activity of ethanolic extracts of these species.