Chemical Constituents, Larvicidal Effects and Radical Scavenging Activity of Tetracera breyniana Schltdl. (Dilleniaceae).

Extracts and fractions from the leaves and stems of Tetracera breyniana Schltdl. were evaluated against the fourth instar Aedes aegypti larvae and ability to scavenge free radicals. Fractions that provided the best results were fractionated on silica gel column to afforded three flavonoils (quercetin, 7-O-methylquercetin and 7-Omethylkaempferol) and two terpenoids (β-sitosterol and betulinic acid). These compounds were identified on basis of their physical and NMR spectral data and by comparison with literature data. With exception of quercetin, all other compounds are been described for the first time in the investigated species. In the larvicidal assays, when compared to synthetic insecticide Temephos, only hexane fraction from stem was effective (LD50 72.08 g/mL). In the DPPH assays, EtOAc fractions from the leaves (CI50 74.15 ± 14.73 g/mL) and stem (IC50 39.87 ± 13.46 g/mL), of which quercetin was isolated, showed the best results when compared with the positive standards used while CHCl3 fractions of both plant parts, of which methylated flavonols were isolated, showed only a moderate activity. Possibly these constituents are responsible in part for the radical scavenging activities observed. Subsequently, evaluation of all isolated compounds will be needed to confirm the active component.

Triterpenos de Guettarda grazielae M.R.V. Barbosa (Rubiaceae) / Triterpenes from Guettarda grazielae M.R.V. Barbosa (Rubiaceae)

O presente trabalho descreve o isolamento e a identificação estrutural de seis triterpenos (acetato de ±-amirina, cicloartenona, 3²,19±,23-triidroxi-urs-12-eno e os ácidos ursólico, 3-²-O-²-D-glicopiranosilquinóvico e 3²,6²,19±,23-tetraidroxi-urs-12-en-28-óico), além de um fitoesteróide (sitostenona) de extratos das folhas, cascas do caule e caule de Guettarda grazielae M.R.V. Barbosa (Rubiaceae). Os compostos isolados, exceto o ácido 3-²-O-²-D-glicopiranosilquinóvico, estão sendo descritos pela primeira vez no gênero Guettarda e foram identificados com base na análise de dados espectrais de RMN, incluindo APT e DEPT, bem como pela comparação com dados da literatura.

This work describes the isolation and structural identification of six triterpenes (a-amyrin acetate, cycloartenone,3²,19±,23-trihydroxyurs-12-ene,andursolic,3-²-O-²-D-glucopyranosylquinovic, 3²,6²,19±,23-tetrahydroxyurs-12-en-28-oic acids), beside a phytosteroid (sitostenone) from leaves, stem barks and stems of Guettarda grazielae (Rubiaceae). All isolated compounds, except 3-²-O-²-D-glucopyranosylquinovic acid, are being described for the first time in the genus Guettarda and were identified on basis of the spectral NMR data, including APT and DEPT, as well as by comparison with data of the literature.

Terpenóides e avaliação do potencial antimalárico, larvicida, anti-radicalar e anticolinesterásico de Pouteria venosa (Sapotaceae) / Terpenoids and evaluation of the antimalarial, larvicidal, anti-radicalar and anticholinesterase potential of Pouteria venosa (Sapotaceae)

O presente trabalho descreve o isolamento de quatro triterpenos (taraxerol, ácido ursólico, ácido 3b,19a,23-triidroxiurs-12-en-28-óico e ácido 2a,3a,19a,23-tetraidroxiurs-12-en-28-óico) e um fitoesteróide (espinasterol), bem como a avaliação do potencial antimalárico (cepa NK-65 do Plasmodium berghei), larvicida (larvas do 4º instar do Aedes aegypti), anti-radicalar (2,2-difenil-1-picril-hidrazila, DPPH) e anticolinesterásico de extratos das folhas, cascas do caule e caule de Pouteria venosa (Mart.) Baehni. Todos os compostos isolados estão sendo descritos pela primeira vez nesta espécie e foram identificados com base na análise de dados espectrais (IV e RMN, incluindo APT e DEPT), bem como pela comparação com dados descritos na literatura.

This work describes the isolation of four triterpenes (taraxerol, ursolic acid, 3b,19a,23-trihydroxyurs-12-en-28-oic acid and 2a,3a,19a,23-tetrahydroxyurs-12-en-28-oic acid) and a phytosteroid (spinasterol), as well as a preliminary evaluation of antimalarial (NK-65 strains of Plasmodium berghei), larvicidal (4th instar of Aedes aegypti), anti-radicalar (2,2-diphenyl-1-pycryl-hydrazyl, DPPH) and anticholinesterase activities of Pouteria venosa (Mart.) Baehni extracts from leaves, stem barks and stems. All isolated compounds are being described for the first time in this species and were identified on basis of the spectral data (IR and NMR, including APT, DEPT), as well as by comparison with literature data.