Four new clerodane diterpenes, casearupestrins A-D (1-4), were isolated from the leaves of Casearia rupestris. Compounds 1 and 4 were acetylated to yield 2,7-di-O-acetylcasearupestrin A (5) and 2,6-di-O-acetylcasearupestrin D (6). All compounds were evaluated for cytotoxicity against a small panel of human cancer cell lines. Casearupestrin A (1) exhibited the most potent activity against MDA/MB-435 (human melanoma) and SF-295 (human glioblastoma) cells, superior to that of the standard drug doxorubicin.

The fruits of Dipteryx lacunifera, known as fava de morcego and garampara, comprise pleasant tasting kernels that contain high amounts of fatty acids (mainly oleic acid) and are commonly consumed by inhabitants of the northeast of Brazil. In the present study, the crude EtOH extract of the fruit kernels was separated into hexane-, Et 2 O-, AcOEt-, and H 2 O-soluble fractions. The Et 2 O fraction was found to exhibit the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity in vitro, and was subjected to further fractionation. Column chromatography over silica gel and Sephadex LH-20, followed by preparative HPLC-C 18 , afforded (À)-eriodictyol (1), (À)-butin (2), luteolin (3), 3',4',7trihydroxyflavone (4), butein (5), and sulfuretin (6). The antiradical activities of compounds 1, 2, 4, and 6, together with the positive controls rutin, butylated hydroxy toluene (BHT), and tert-butylhydroquinone (TBHQ), were evaluated with the DPPH assay and were found to decrease in the order rutin > 4 > 1 > 6 > 2 > TBHQ > BHT.Introduction. -Various classes of metabolites have been isolated from members of the genus Dipteryx (family Leguminosae-Papilionoideae) including coumarins, isoflavones, fatty acids, triterpenoids, and furanocassane diterpenoids [1 -7]. Kernels of the fruits of Dipteryx lacunifera Ducke, a species that is widely distributed in the northeast of Brazil, where it is popularly known as fava de morcego or garampara, are prized for their pleasant flavor, high energy content, and anti-oxidant activities [8] [9]. In previous studies, the fruits of this species have been found to contain sesquiterpenoids [1], furanocassane diterpenoids and fatty acids [1] [9], but no information is available concerning the occurrence of the polar constituents that are associated with its antiradical properties.Free radicals are known to play a key role in biological damage and are implicated in the etiology of several degenerative conditions such as rheumatoid arthritis, coronary arterial disease, diabetes, and cancer. The consumption of various plant products, including vegetables, fruits, and herbal medicines, possessing radical-scavenging activities is apparently associated with low risk for these diseases [10 -13]. In the present study, an activity-guided fractionation of an Et 2 O-soluble fraction obtained from a crude ethanolic extract of fruit kernels of D. lacunifera was conducted, and four 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging flavonoids were isolated and identified. Since the fruits are already accepted for human consumption in Brazil, the

Cutaneous secretions produced by amphibians of the family Bufonidae are rich sources of bioactive compounds that can be useful as new chemical templates for agrochemicals. In crop protection, the use of elicitors to induce responses offers the prospect of durable, broad-spectrum disease control using the plant’s own resistance. Therefore, we evaluated the potential of methanolic extracts of cutaneous secretions of two species of amphibians of the family Bufonidae found in the Amazon biome—Rhaebo guttatus (species 1) and Rhinella marina (species 2)—in the synthesis of phytoalexins in soybean cotyledons, bean hypocotyls, and sorghum mesocotyls. Additionally, changes in the enzyme activity of β-1,3-glucanase, peroxidase (POX), and polyphenol oxidase (PPO) and in the total protein content of soybean cotyledons were determined. In the soybean cultivar ‘TMG 132 RR’, our results indicated that the methanolic extract of R. guttatus cutaneous secretions suppressed glyceollin synthesis and β-1,3-glucanase activity and increased POX and PPO activities at higher concentrations and total protein content at a concentration of 0.2 mg/mL. On the other hand, the methanolic extract of R. marina cutaneous secretions induced glyceollin synthesis in the soybean cultivars ‘TMG 132 RR’ and ‘Monsoy 8372 IPRO’ at 0.1–0.2 mg/mL and 0.2 mg/mL, respectively. The methanolic extract of R. marina cutaneous secretions also increased the specific activity of POX and PPO in ‘Monsoy 8372 IPRO’ and ‘TMG 132 RR’, respectively, and decreased the activity of β-1,3-glucanases in ‘Monsoy 8372 IPRO’. At 0.3 mg/mL, it stimulated phaseolin synthesis. The extracts did not express bioactivity in the synthesis of deoxyanthocyanidins in sorghum mesocotyls. The study in soybean suggests that the bioactivity in defense responses is influenced by cultivar genotypes. Therefore, these results provide evidence that extracts of cutaneous secretions of these amphibians species may contribute to the bioactivity of defense metabolites in plants.

Bufadienolides are the main active compounds in the Bufonidae family of frogs. Recent studies have demonstrated cytotoxic and/or antitumor activity in these molecules. A HPLC-DAD method was developed and validated to quantify three bufadienolides (telocinobufagin, marinobufagin and bufalin) in ethyl acetate extracts of the cane toad poison frogs and smooth-sided toad. The chromatographic analysis was performed on Phenomenex Luna C18 (250.0 × 4.6 mm, 5 μm), using gradient elution with acetonitrile and water, at a flow rate of 1.0 mL min(-1) and detection at 296 nm. The method showed linearity (r > 0.999) and adequate recovery values (86%-111%). The limits of quantification of bufadienolides were 7.4 μg mL(-1) for telocinobufagin, 4.2 μg mL(-1) for marinobufagin and 4.0 μg mL(-1) for bufalin. Intraday and interday values of the method were evaluated and presented standard deviation values lower than 5%. The method was successfully applied to quantify the bufadienolides in the venom extract of the cane toad, which showed a content of 60% of marinobufagin. The same method was not selective for the venom extract of the Rhaebo guttatus, despite being linear, accurate and precise, requiring the development of a technique that presents a greater selectivity.