Rosaceae consists of a large family of plants, represented by fruits such as plums, cherries, damson plums, quinces, strawberries, pears and peaches.1) The plants to the genus Rubus, have been traditionally used to treat different diseases, particularly diabetes.2-4) Chemical and pharmacological studies have shown that some species produce active principles that exert antigastropathic, antiinflammatory, antioxidant activity.5-7) Besides these activities, it has been reported that extracts of some species of this genus are potential antimicrobial and analgesic sources. [8][9][10] Phytochemical studies carried out with these plants indicate the presence of steroids, triterpene and ellagic acid derivatives. 8,9,11) Recently, we have shown that another species, R. imperialis, presents hypoglycaemic, cytotoxic and antinociceptive actions. 9,[11][12][13] The main isolated active compound, named niga-ichigoside F1, showed marked antinociception and its mechanism of action appears to be related to the dopaminergic, cholinergic, glutamatergic, and tachykininergic and oxinitrergic systems. 14)Rubus rosaefolius, popularly known as "amora-do-mato" or "amora-vermelha" in Brazil, is a shrub measuring between 4 and 5 m, and is well distributed in the South of Brazil. 1,15) The current study extends our previous work on the biological properties of the Rubus species, and describes its phytochemical analysis and in vivo antinociceptive activity against two pain models in mice (writhing and formalin tests) of the extract, fractions and a pure compound isolated from the aerial parts of R. rosaefolius. Phytochemical Analysis Air-dried material from R. rosaefolius (700 g) was cut into small pieces and macerated with methanol at room temperature for 7 d. After filtration, the solvent was removed by rotatory evaporation under reduced pressure, yielding the respective methanolic extract (ME). Parallel to this, a hydroalcoholic extract (HE) was prepared through maceration of 100 g of plant with an ethanol-water (50 : 50) mixture and stored for use in the pharmacological test. The methanolic extract (35 g), were then suspended in a MeOH : water mixture (9 : 1) and successively partitioned with n-hexane, dichlomethane, ethyl acetate and n-butanol, to provide the respective fractions. The hexane and dichloromethane fractions (7.4, 4.2 g) were chromatographed on silica gel column eluted with a hexane : acetone mixture with increasing polarity. Similar fractions, which showed a positive reaction with anisaldehyde sulfuric reagents, were combined and rechromatographed as in the The Rubus species has been used in folk medicine to treat several ailments, including infectious and dolorous diseases. In this work we evaluate the phytochemical and analgesic activity of hydroalcoholic extract (HE), some fractions (hexane, dichloromethane, ethyl acetate and butanolic), as well as a pure compound denoted as 28-methoxytormentic acid (1) obtained from aerial parts of R. rosaefolius. The compounds were isolated and identified by chromatographic and spect...