Further drimane sesquiterpenes from Drimys brasiliensis stem barks with cytotoxic potential.

Drimys brasiliensis Miers (Winteraceae) is used in folk medicine for the treatment of cancer. Its anti-tumor activity has been demonstrated in vitro models using extracts and isolated compounds. This study investigates the cytotoxic effects of stem bark extracts of D. brasiliensis as well as isolated compounds that may be responsible for the activitys and evaluates them in leukemia cells. The stem bark extract were subjected to column chromatography, and the structures of compounds were elucidated based on spectroscopic methods by using NMR and infrared spectroscopy and GC/MS. The cytotoxicity of the isolated compounds was evaluated in chronic myeloid (K562) and acute B lymphoblastic (Nalm6) leukemia cells using tetrazolium assay (MTT). Two new compounds were isolated 1ß-O-p-methoxy-E-cinnamoyl-5α-keto-11α-enol-albicanol (1a) and the isomer 1ß-O-p-methoxy-E-cinnamoyl-5α-keto-11ß-enol-albicanol (1b) and 1ß-O-p-methoxy-E-cinnamoyl-isodrimeninol (2). The known compounds polygonal acid (3a) and the isomer isopolygonal acid (3b), fuegin (4a) and the isomer epifuegin (4b), the mixture drimanial (5) and 1ß-O-(p-methoxy-E-cinnamoyl)-6α-hydroxypolygodial (6) were also isolated. The drimanes (1-4) and drimanial (5), 1ß-(p-coumaroyloxy)-polygodial (7), 1ß-(p-methoxycinnamoyl)-polygodial (8), and polygodial (9) isolated previously were assessed in tumor cells. The IC50 values were between 3.56 and 128.91 µM. 1-ß-(p-cumaroiloxi)-polygodial showed the best result with IC50 8.18 and 3.56 µM by K562 and Nalm6, respectively. The chloroform extract of the stem bark of D. brasiliensis is a great source of drimane sesquiterpenes. Our experimental data suggest that drimanes are responsible for cytotoxicity activity demonstrated by this species, especially those with the aldehyde group linked to carbons C-11 and C-12.

Drimanes from Drimys brasiliensis with leishmanicidal and antimalarial activity.

This paper evaluates CHCl3 and CH3OH extracts of the stem bark, branches and leaves of Drimys brasiliensis and drimane sesquiterpenes isolated from the stem bark against strains of Leishmania amazonensis and Leishmania braziliensis promastigotes and Plasmodium falciparum trophozoites. All of the extracts and compounds were tested in cell lines in comparison with reference standards and cell viability was determined by the XTT method. The CHCl3 and CH3OH extracts from the stem bark and branches yielded promising results against two strains of Leishmania, with 50% inhibitory concentrations (IC50 ) values ranging from 39-100 µg/mL. The CHCl3 extract of the stem bark returned IC50 values of 39 and 40.6 µg/mL for L. amazonensis and L. braziliensis, respectively. The drimanes were relatively effective: 1-ß-(p-coumaroyloxy)-polygodial produced IC50 values of 5.55 and 2.52 µM for L. amazonensis and L. braziliensis, respectively, compared with 1-ß-(p-methoxycinnamoyl)-polygodial, which produced respective IC50 values of 15.85 and 17.80 µM. The CHCl3 extract demonstrated activity (IC50 of 3.0 µg/mL) against P. falciparum. The IC50 values of 1-ß-(p-cumaroyloxyl)-polygodial and 1-ß-(p-methoxycinnamoyl)-polygodial were 1.01 and 4.87 µM, respectively, for the trophozoite strain. Therefore, the results suggest that D. brasiliensis is a promising plant from which to obtain new and effective antiparasitic agents.

Drimanes from Drimys brasiliensis with leishmanicidal and antimalarial activity

This paper evaluates CHCl3 and CH3OH extracts of the stem bark, branches and leaves of Drimys brasiliensis and drimane sesquiterpenes isolated from the stem bark against strains of Leishmania amazonensis and Leishmania braziliensis promastigotes and Plasmodium falciparum trophozoites. All of the extracts and compounds were tested in cell lines in comparison with reference standards and cell viability was determined by the XTT method. The CHCl3 and CH3OH extracts from the stem bark and branches yielded promising results against two strains of Leishmania, with 50% inhibitory concentrations (IC50 ) values ranging from 39-100 µg/mL. The CHCl3 extract of the stem bark returned IC50 values of 39 and 40.6 µg/mL for L. amazonensis and L. braziliensis, respectively. The drimanes were relatively effective: 1-β-(p-coumaroyloxy)-polygodial produced IC50 values of 5.55 and 2.52 µM for L. amazonensis and L. braziliensis, respectively, compared with 1-β-(p-methoxycinnamoyl)-polygodial, which produced respective IC50 values of 15.85 and 17.80 µM. The CHCl3 extract demonstrated activity (IC50 of 3.0 µg/mL) against P. falciparum. The IC50 values of 1-β-(p-cumaroyloxyl)-polygodial and 1-β-(p-methoxycinnamoyl)-polygodial were 1.01 and 4.87 µM, respectively, for the trophozoite strain. Therefore, the results suggest that D. brasiliensis is a promising plant from which to obtain new and effective antiparasitic agents.