The Stevia genus belongs to Asteraceae Family, and comprise about 220-230 species, most of them located in South America1. Stevia has a widely range of chemical constituents, however, sesquiterpenoids are the major and most typical constituents described from the aerial parts of this genus. Stevia leptophylla Sch.Bip. ex Baker is a herb, native to Brazil, and often found in Parana State2. Since there is no information about the chemistry of this specie, the aim of this work is to investigate the secondary metabolites accumulated in S. leptophylla, and to evaluate the antioxidant, anti-Leishmania and antiviral activity of extracts and isolated compounds. Dried aerial parts of S. leptophylla (27.51 g), collected in Ponta Grossa, Parana, in August 2012, were powered and exhaustively extracted with methanol at room temperature. Vacuum concentration yielded the crude methanol extract (4.53 g), which was resuspended in MeOH:H2O (1:1) and partitioned into hexane, CHCl3, EtOAc and BuOH. The CHCl3 fraction (1.0 g) was submitted to a chromatographic column (CC) over silica gel and to afford one compound (Sl-1). The fractions BuOH and hydromethanolic were washed with methanol, and an insoluble yellow powder precipitated from this solution (Sl-2). Compound SI-1 was identified, by comparison of their spectroscopic data with those reported in the literature, as the sesquiterpenic lactone Xerantholide3. The 1H and 13C NMR spectra obtained for compound SI-2 showed the presence of characteristics signals of 4-oxo-chromene derivatives, however the presence of a duplicate signal at 13C NMR spectra allowed the identification of SI-2 as dimeric compound, which was called as Leptophyllene. This dimeric 4-oxo chromene derivative skeleton is being described for the first time. The identity of Leptophyllene was confirmed based on its HRESIMS (m/z 353.0739 [M - H]-, calcd 353.0789), and [M - 4H]- 350.9823 confirming the presence of four acid hydrogens atoms in SI-2. All fractions and the isolated compounds were evaluated against Leishmania amazonensis promastigotes, cytotoxicity and antiviral activity, furthermore, the antioxidant activity using Frap, DPPH and Xantine Oxidase assays were performed. The best results obtained for Sl-1 were in vitro cytotoxicity with CC50= 19.67 ± 1.15 µM and IC50= 8.75 ± 0.64 µg/mL for Leishmania amazonensis promastigotes. Sesquiterpenic lactones are known for its antileishmanial activity due to its exocyclic double bound conjugated to carbonyl group. Compound Sl-2 showed a prominent antioxidant activity (Xanthine oxidase assay) with IC50= 3.46 ± 0.15 µg/mL.