Dermatomycosis causes highly frequent dermal lesions, and volatile oils have been proven to be promising as antifungal agents. The antifungal activity of geraniol, nerol, citral, neral and geranial (monoterpenes), and terbinafine and anidulafungin (control drugs) against seven opportunistic pathogenic yeasts and four dermatophyte species was evaluated by the Clinical and Laboratory Standards Institute microdilution tests. Monoterpenes were more active against dermatophytes than yeasts (geometric mean of minimal inhibitory concentration (GMIC) of 34.5 and 100.4μg.ml-1, respectively). Trichophyton rubrum was the fungal species most sensitive to monoterpenes (GMIC of 22.9μg.ml-1). The trans isomers showed higher antifungal activity than the cis. The mechanism of action was investigated evaluating damage in the fungal cell wall (Sorbitol Protection Assay) and in the cell membrane (Ergosterol Affinity Assay). No changes were observed in the MIC of monoterpenes in the sorbitol protection assay. The MIC of citral and geraniol was increased from 32 to 160μg.ml-1 when the exogenous ergosterol concentrations was zero and 250μg.ml-1, respectively. The monoterpenes showed an affinity for ergosterol relating their mechanism of action to cell membrane destabilization

More than 40% of the World population is at risk of contracting malaria, which affects primarily poor populations in tropical and subtropical areas. Antimalarial pharmacotherapy has utilised plant-derived products such as quinine and artemisinin as well as their derivatives. However, worldwide use of these antimalarials has caused the spread of resistant parasites, resulting in increased malaria morbidity and mortality. Considering that the literature has demonstrated the antimalarial potential of triterpenes, specially betulinic acid (1) and ursolic acid (2), this study investigated the antimalarial activity against P. falciparum chloroquine-sensitive 3D7 strain of some new derivatives of 1 and 2 with modifications at C-3 and C-28. The antiplasmodial study employed flow cytometry and spectrofluorimetric analyses using YOYO-1, dihydroethidium and Fluo4/AM for staining. Among the six analogues obtained, compounds 1c and 2c showed excellent activity (IC₅₀ = 220 and 175 nM, respectively) while 1a and b demonstrated good activity (IC₅₀ = 4 and 5 μM, respectively). After cytotoxicity evaluation against HEK293T cells, 1a was not toxic, while 1c and 2c showed IC₅₀ of 4 μM and a selectivity index (SI) value of 18 and 23, respectively. Moreover, compound 2c, which presents the best antiplasmodial activity, is involved in the calcium-regulated pathway(s).

Ilex paraguariensis St. Hilaire is a South American tree from which leaves and twigs are used to prepare a commonly consumed tea in several South American countries. The plant is known as "erva-mate" in Portuguese or "yerba mate" in Spanish. Considering the potential use of the saponins as surfactant as well as its therapeutic potential, the present work was designed to propose extraction and quantitation methods for the saponins present in Ilex paraguariensis. The saponins were extracted by decoction, hydrolyzed and quantified by a HPLC method with UV detection. The saponins concentration was expressed in ursolic acid (total saponins). The method showed linearity for ursolic acid in the range of 13.5 to 135 µg mL-1. The aqueous extract presented total saponins concentration of 352 µg mL-1. The results also suggest the possibility of use of similar method for assaying triterpenoid saponins in other plants.