Phytochemical Characterization and Antimicrobial Properties of a Hydroalcoholic Extract of Tristerix corymbosus (L) Kuijt, a Chilean Mistletoe Species Hosted on Salix babylonica (L)

<b>Background/Objectives:</b> The genus <i>Tristerix</i> comprises at least ten species, found from southern Chile to Colombia in South America. In Chile, several species of these hemiparasitic plants are known as quitral or quintral. Quitral, mainly <i>T. corymbosus</i> (syn. <i>T. tetrandus</i>), is used in alternative medicine for its anti-inflammatory, digestive, hemostatic, hypocholesterolemic, and wound-healing properties. This study investigates the phytochemical composition and antimicrobial properties of <i>T. corymbosus</i>. <b>Methods:</b> A hydroalcoholic extract of <i>T. corymbosus</i> was prepared from leaves and small branches. The addition of methanol, on the extract, produced precipitation allowing us to isolate a methanol-soluble fraction, a brown powder obtained after filtration, and a tar-like residue remaining in the flask. These fractions were resuspended and tested for antimicrobial activity. <b>Results:</b> All fractions showed activity against <i>Streptococcus pyogenes</i>, but not <i>E. coli</i>. The brown powder exhibits the strongest potency against Gram-positive bacteria, some Gram-negative and <i>C. albicans</i>. HPLC-MS analysis revealed presence of lipidic compounds with surfactant properties. <b>Conclusions:</b> The abundant lipidic molecules present in the analyzed fraction likely account for the antimicrobial effects through affecting membrane structure of microorganisms supporting the traditional wound-healing uses of <i>T. corymbosus</i> in ancestral medicine.