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Tabernaemontana catharinensis root bark ethanol extract, EB2 fraction and the MMV alkaloid (12-methoxy-4-methylvoachalotine) were evaluated for their antimicrobial activities. T. catharinensis ethanol extract was effective against both strains of the dermatophyte Trichophyton rubrum at concentrations of 2.5 mg/mL (wild strain) and 1.25 mg/mL (mutant strain), while the EB2 fraction and MMV alkaloid showed a strong antifungal activity against wild and mutant strains with MIC values of <0.02 and 0.16 mg/mL, respectively. The EB2 fraction showed a strong antibacterial activity against ATCC strains of S. aureus, S. epidermidis, E. coli and P. aeruginosa with MICs from <0.02 to 0.04 mg/mL, as well as against resistant clinical isolates species of Enterococcus sp, Klebsiella oxytoca, Citrobacter, K. pneumoniae, P. mirabilis, S. aureus, S. epidermidis, E. coli and P. aeruginosa with MIC values ranging from 0.04 to 0.08 mg/mL. The MMV alkaloid presented a MIC of 0.16 mg/mL against the strains of S. aureus and E. coli ATCC. For the resistant clinical isolates Enterococcus sp, Citrobacter, S. aureus, S. epidermidis, E. coli and P. aeruginosa the MIC of MMV ranged from 0.08 to 0.31 mg/mL. The chromatography analysis of the EB2 fraction revealed the presence of indole alkaloids, including MMV, possibly responsible for the observed antimicrobial activity.

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ABSTRACT. Cancer has become the leading cause of death in developing countries due to increased life expectancy of the population and changes in lifestyle. Studies on active principles of plant have motivated researchers to develop new antitumor agents that are specific and effective for treatment of neoplasms. Kaurane diterpenes are considered important compounds in the development of new and highly effective anticancer chemotherapeutic agents due to their cytotoxic properties in the induction of apoptosis. We evaluated the cytotoxic and apoptotic activity of the epimer of kaurenoic acid (EKA) isolated from the medicinal plant Croton antisyphiliticus (Euphorbiaceae) toward tumor cell lines HeLa and B-16 and normal fibroblasts 3T3. Based on analyses with the MTT test, EKA showed cytotoxic activity, with half maximal inhibitory concentration values of 59.41, 68.18 and 60.30 µg/ mL for the B-16, HeLa and 3T3 cell lines, respectively. The assay for necrotic or apoptotic cells by differential staining showed induction of apoptosis in all three cell lines. We conclude that EKA is not selective between tumor and normal cell lines; the mechanism of action of EKA is induction of apoptosis, which is part of the innate mechanism of cell defense against neoplasia.

Anemopaegma arvense (Vell) Stellf. ex de Souza belongs to the family Bignoniaceae, and is popularly known as catuaba. To evaluate the cytotoxic and antimicrobial activity of A. arvense, fraction F3 and flavonoids 1 (quercetin 3-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside) (rutin) and flavonoid 2 (quercetin 3-O-α-L-rhamnopyranosyl-(1→6)-β-D-galactopyranoside) were isolated from the leaves of this plant. Fraction F3 and flavonoids 1 and 2 exhibited no antibacterial activity. Furthermore, no cytotoxic activity of fraction 3 or flavonoids 1 and 2 was observed against the tumor cells tested. However, analysis of the antifungal activity of flavonoids 1 and 2 revealed minimum inhibitory concentrations of 0.5 and 0.25 mg/mL, respectively, against the Trichophyton rubrum strains tested (wild type and mutant). This study demonstrates for the first time the antifungal activity of isolated flavonoids, validating the same activity for A. arvense. Uniterms:Bignoniaceae. Anemopaegma arvense/phytochemistry. Catuaba/phytochemistry. Flavonoids/ antifungal activity. Plant extract/evaluation.Anemopaegma arvense pertence à família Bignoniaceae, sendo conhecida popularmente como Catuaba. Para avaliação de sua atividade citotóxica e antimicrobiana, a fração cromatográfica F3 e os flavonoides 1 (quercetina 3-O-α-L-ramnopiranosil-(1→6)-β-D-glucopiranosídeo) (rutina) e flavonoide 2 (quercetina 3-O-α-L-ramnopiranosil-(1→6)-β-D-galactopiranosídeo) foram isolados das folhas de A. arvense. A fração 3 e os flavonoides não apresentaram atividade antibacteriana. Nenhuma atividade citotóxica foi observada para a fração F3 e para os flavonoides, quando avaliados contra as células tumorais em teste. Entretanto, e considerando a atividade antifúngica, o flavonóide 1 apresentou valor de concentração inibitória mínima (CIM) de 0,5 mg/mL, enquanto o flavonóide 2, CIM de 0,25 mg/mL contra as cepas selvagem e mutante de Trichophyton rubrum, demonstrando, pela primeira vez, que os flavonoides isolados possuem atividade antifúngica, o que valida a mesma atividade para A. arvense.Unitermos: Bignoniaceae/fitoquímica. Anemopaegma arvense/fitoquímica. Catuaba/fitoquímica. Flavonóides/atividade antifúngica. Extrato vegetal/avaliação. INTRODUCTIONThe family Bignoniaceae comprises about 800 plant species that are found mainly in the Neotropical region (Gentry, 1980). In Brazil, several plants of this family are used in folk medicine as astringent and against fever, rheumatism, diarrhea, cancer and microbial infections (Pio Côrrea, Penna, 1969;Fenner et al., 2006). Anemopaegma arvense (Vell) Stellf. ex de Souza is a species of the family Bignoniaceae, which is popularly known as "catuaba". Commercially available formulations of this plant are used as aphrodisiac (Manabe et al., 1992). The major components identified in A. arvense are flavonoids, catuabins, alkaloids, tannins, and resins (Charam, 1987;Zanolari et al., 2005;Tabanca et al., 2007). Flavonoids are becoming the subject of anti-infective research and many groups have isolated and identified the str...