Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) ; Processo FAPESP: 02/05503-6 ; The methanolic extract from the barks of the medicinal plant Qualea parviflora (Vochysiaceae) was fractionated by column chromatography over silica gel followed by gel permeation over Sephadex LH-20 to give 3,3′-di-O- methylellagic acid-4-O-β-D-glucopyranoside (1), 3-O-methylellagic acid-4′-O-α-L-rhamnopyranoside (2), 3,3′,4-tri-O-methylellagic acid-4′-O-β-D-glucopyranoside (3), and 3,3′-di-O-methylellagic acid (4), together with triterpenes and saponins. We also performed comparative analyses among this species and Q. grandiflora and Q. multiflora using high-pressure liquid chromatography. The biological assays showed that, when compared to the standard ellagic acid, compounds 1-4 are less cytotoxic but have a lower capacity of stimulating murine peritoneal macrophages to release nitric oxide and tumoural-α necrose factor. © 2008 Verlag der Zeitschrift für Naturforschung.