Abstract The chemical investigation of Eugenia pyriformis, popularly known as uvaia, led to the isolation of three compounds, the triterpene β-amiryn (1) and the porphyrin derivatives pheophytin a (2) and b (3). Their structures were assigned based on spectroscopic NMR analysis, as well as by comparison with literature data. Most of the compounds found in the essential oil from leaves are terpenes derivatives, such as ο-cymene; 1,8-cineol; linalol, terpinen-4-ol; 2-carene. Flavonoids, steroids and/or terpenoids, lactones, saponins, tannins and fixed acids were detected in both the leaf and stem crude extracts and fractions generated from the Brazilian E. pyriformis plant. According to the results of the DPPH assay, the ethyl acetate fraction of the leaf extract showed higher antioxidant activity than the other samples tested. In the phosphomolybdenum complex assay, the crude ethanol extract of the leaf and stem, and the ethyl acetate fraction of the leaf, showed a higher antioxidant capacity than rutin. It was observed that the chloroform and ethyl acetate fractions of the leaf, and the hexane, ethyl acetate and hydroalcoholic fractions of the stem were toxic to Artemia salina brine shrimp with LD50 < 1.0 µg/mL. The hexane fraction of the stem was also allelopathic in inhibiting the radicle growth of Lactuca sativa seeds. These results adding contributions to chemical and biological studies of this medicinal species.

Eugenia pyriformis Cambess., known as uvaia, is a species of Myrtaceae native to Brazil. Its leaves are used in folk medicine to treat gout because they possess the property of inhibiting xanthine oxidase, an enzyme involved in the conversion of xanthine into uric acid. The objective of this work was to study the leaf and stem morpho-anatomy of E. pyriformis, in order to contribute to what is known about the Brazilian flora, and this medicinal plant and potential vegetal drug. Samples of mature leaves and young stems were fixed and sectioned by freehand, or embedded in glycol methacrylate and sectioned with a microtome, and then stained. In addition, microchemical tests and scanning electron microscopy were performed. The leaf is simple, symmetric, elliptic-lanceolate, with an acute apex and base, and an entire margin. The epidermis is uniseriate and coated with a moderately thick cuticle. The stomata are anomocytic and inserted at the same level as the adjacent cells. Unicellular non-glandular trichomes are abundant on the abaxial surface. The mesophyll is dorsiventral. In transverse section, the midrib is plano-convex and the petiole is circular, and both of these structures have a single bicollateral vascular bundle. In the stem, the vascular cylinder consists of external phloem, xylem and internal phloem, traversed by narrow rays. Phenolic compounds, druses and prismatic crystals of calcium oxalate are also present in the leaf and stem.