Marize Terezinha Lopes Pereira Peres

Chemical composition and antimicrobial activity of Croton urucurana Baillon (Euphorbiaceae).

In the methanolic extract of Croton urucurana Baillon (Euphorbiaceae) a number of known compounds, such as acetyl aleuritolic acid, stigmasterol, beta-sitosterol, campesterol, beta-sitosterol-O-glucoside, sonderianin, catechin and gallocatechin were isolated and identified by MS and NMR spectroscopy, HRGC and data from literature. The antibacterial activity of the aqueous-EtOH extract, some fractions of the methanolic extract and some of the isolated compounds, were tested against Staphylococcus aureus and Salmonella typhimurium. Acetyl aleuritolic acid exhibits the best minimum inhibitory concentration (MIC) against both Staphylococcus aureus and Salmonella typhimurium.

Potencial alelopático de espécies de Pteridaceae (Pteridophyta)

Ferns exhibit a strong pattern of dominance in the areas in which they grow, forming almost pure associations, where only a few species coexist. Ethanol extractions of five species of Pteridaceae, in concentrations of 250, 500 and 1,000mg.L-1, were evaluated using germination and growth bioassays under laboratory conditions, to verify the potential for allelopathic activity against Lactuca sativa (L.) strain Grand rapids (lettuce) and Allium cepa (L.) strain Baia periforme (onion). Adiantopsis radiata (L.) Fee, Adiantum serratodentatum Willd. and Pteris denticulata Sw. var. denticulata were collected at the Fazenda Azulao, situated in the municipality of Dourados, MS, Brazil, while the species Adiantum tetraphyllum Willd. and Pityrogramma calomelanos (L.) Link var. calomelanos were collected at the Fazenda Curupi, situated in Ponta Pora, MS, Brazil. The bioassays carried out revealed the following: 1) the five vegetal extracts did not significantly interfere with the germination of the lettuce or onion; 2) the extracts of Adiantum serratodentatum, Adiantum tetraphyllum, Adiantopsis radiata, and Pityrogramma calomelanos inhibited the radicular growth of the lettuce seedlings; 3) Adiantum serratodentatum, Adiantum tetraphyllum, and Pteris denticulata inhibited the growth of the hypocotyls of lettuce; 4) Adiantopsis radiata, Adiantum serratodentatum, and Pteris denticulata inhibited both the growth of the radicles and the coleoptiles of the onion seedlings. The results obtained so far permit the conclusion that the ethanol extracts of the species studied contain substances that modify the growth of lettuce and onion seedlings.

Chemical composition and evaluation of antibacterial and antioxidant activities of the essential oil of Croton urucurana Baillon (Euphorbiaceae) stem bark

O oleo essencial obtido a partir das cascas do caule de Croton urucurana Baillon (Euphorbiaceae) foi analisado por CG e CG-EM. 83 compostos foram identificados, sendo borneol (14,7%), acetato de bornila (5,2%), 1-isopropil-7-metil-4-metileno-1,3,4,5,6,8-hexaidro2H-naftalen-4a-ol (14,7%), sesquicineol (10,5%) e epoxido de γ-gurjuneno (5,4%) os principais componentes. Para o oleo essencial bruto, foi determinada em 3,21 mg mL -1 a EC 50 no ensaio de atividade antioxidante frente ao radical livre DPPH. A fracao do oleo essencial bruto que apresentou atividade antioxidante foi purificada por CCD sobre silica gel. Analises de CG e CG-EM revelaram que α-bisabolol (38,3%), α-eudesmol (9,3%) e guaiol (8,2%) sao os principais componentes da fracao antioxidante. A EC 50 medida no teste frente ao DPPH foi de 1,05 mg mL -1 para a fracao bioativa. Foi determinada a atividade antimicrobiana do oleo essencial bruto frente a sete bacterias Gram-positivas e Gram-negativas e tres fungos. Os valores de CIM medidos variaram de 1,25 a 10,00 mg mL -1 . The essential oil obtained from the stem bark of Croton urucurana Baillon (Euphorbiaceae) was analysed by GC and GC-MS. 83 compounds were identified and borneol (14.7%), bornyl acetate (5.2%), 1-isopropyl-7-methyl-4-methylene-1,3,4,5,6,8-hexahydro-2H-naphthalen-4a-ol (14.7%), sesquicineole (10.5%) and γ-gurjunene epoxide (5.4%) were the main components. The EC 50 value of the crude essential oil in the DPPH free radical scavenging assay was 3.21 mg mL -1 . The fraction of the crude essential oil that presented antioxidant activity was purified by prepTLC on silica gel. GC and GC-MS analysis revealed that α-bisabolol (38.3%), α-eudesmol (9.3%) and guaiol (8.2%) were the main components of the antioxidant fraction. The EC 50 value measured for the bioactive oil fraction in the DPPH assay was 1.05 mg mL -1 . The antimicrobial activity of

Potencial alelopático da parte aérea de Senna occidentalis (L.) Link (Fabaceae, Caesalpinioideae): bioensaios em laboratório

A bioatividade das fracoes semipurificadas (hexânica, acetato de etila e etanol-agua) do extrato etanolico das partes aerea de S. occidentalis foi avaliada atraves de ensaios de germinacao e de crescimento de Lactuca sativa (alface), Lycopersicon esculentum (tomate), Allium cepa (cebola) e Triticum aestivum (trigo), em laboratorio. Foram utilizadas tres concentracoes (250, 500, 1000 mg L-1) de cada fracao e um controle nao tratado, com quatro repeticoes de 50 sementes. Os bioensaios de germinacao revelaram que todas as fracoes atrasaram a germinacao de alface, tomate e cebola, e as fracoes hexânica e acetato de etila reduziram a germinabilidade de tomate e cebola. Nos bioensaios de crescimento, a fracao hexânica estimulou o crescimento da raiz e inibiu o crescimento do hipocotilo das eudicotiledoneas. A mesma fracao inibiu o crescimento da raiz e do coleoptilo das monocotiledoneas. A fracao acetato de etila inibiu o crescimento da raiz das plântulas-alvo e o hipocotilo/coleoptilo de tomate e cebola. A fracao etanol-agua estimulou o crescimento da raiz de tomate e do hipocotilo de alface e inibiu o crescimento da raiz de cebola e trigo e, tambem, do coleoptilo de cebola, na concentracao de 1000 mg L-1. Nos bioensaios com herbicidas comerciais foram observados efeitos semelhantes aqueles obtidos na germinacao pelas fracoes e no crescimento pelas fracoes hexânica e acetato de etila. Na cromatografia em camada delgada, foram detectados terpenos na fracao hexânica, compostos fenolicos e alcaloides na fracao acetato de etila. A analise espectrofotometrica revelou que a fracao acetato de etila possui o maior conteudo de compostos fenolicos e flavonoides.

Composição química e atividade alelopática do óleo volátil de Hydrocotyle bonariensis Lam (araliaceae)

Os oleos essenciais sao liquidos aromaticos obtidos de materiais vegetais (flores, folhas, ramos, sementes, ervas, madeira, frutos, raizes e cascas), sendo constituidos por misturas complexas, dentre outras, de terpenoides que podem conter ate 100 ou mais compostos orgânicos. Os terpenos encontrados com maior frequencia nos oleos essenciais sao os monoterpenos, sesquiterpenos e com menor frequ-encia os diterpenos. Seus constituintes terpenicos podem apresentar diversas funcoes orgânicas, como alcoois, cetonas, eteres, esteres e aldeidos. Os terpenos possuem, tambem, diversas funcoes nas plantas atuando como fitoalexinas, repelentes de insetos, agentes de atracao polinica, agentes de defesa contra herbivoros, feromonios, hormonios vegetais, moleculas de sinalizacao e aleloquimicos.

Clerodane diterpenes of croton ururucana

Abstract Sonderianin and two novel furoclerodane diterpenes with a trans A\B ring junction were obtained from the barks of Croton ururucana . Their structures were elucidated by detailed NMR investigation, and the relative configurations established by NOE experiments. 13 C NMR values for the carbonyls of sonderianin were corrected. Furthermore, two catechins were isolated.

Effects of croton urucurana extracts and crude resin on Anagasta kuehniella (Lepidoptera: Pyralidae)

Hundreds of plant species have been studied in orde r to find out the active ingredient responsible for their insecticidal activity against the pests of economic importance. To verify the insecticidal activity in the husk of stem of Croton urucurana Baillon 1864 (Euphorbiaceae) against Anagasta kuehniella Zeller 1879 (Lepidoptera: Pyralidae), the methanolic (EMeOH) extract, dichlor omethane fraction (FDM), ethyl acetate fraction (FA E) and crude resin, incorporated into an artificial diet w ere evaluated. EMeOH (0.5, 1.0 and 2.0%) and crude resin (2.0%) interfered with neither the weight nor the survival of fourth instar larvae and other analyzed paramet ers. FDM (2.0%) fraction caused mortality of 65%, and the ar tificial diet containing 2.0, 1.0 and 0.5% FAE caus ed 100, 55 and 68% mortality respectively when compared with t he control, confirming the least efficiency rates o f food conversion for FDM(2.0%) and FAE(1.0%). The tryptic analysis performed with the midgut fluid of fourth -instar larvae demonstrated that tryptic and chymiotryptic activities for the larvae fed artificial diet containing EMeOH and crude resin were not different.

Evaluation of seasonal changes in chemical composition and antibacterial activity of Elyonurus muticus (sprengel) O. Kuntze (Gramineae)

Aerial parts of Elyonurus muticus were collected in the four seasons of the year in the Brazilian Pantanal and subjected to extractrion with cold ethanol and to hydrodistillation. Sesquiterpenoids (E)-caryophyllene, bicyclogermacrene, spathulenol and caryophyllene oxide were the main components identified in the essential oils and their concentrations varied according to the plant collection period. The essential oils and the ethanolic crude extracts were active against Bacillus cereus MIP 96016, Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923 and were not active against Escherichia coli ATCC 25922. The antibacterial activities varied according to the plant collection period.

Constituintes químicos e avaliação do potencial alelopático de Adiantum tetraphyllum Humb. & Bonpl. Ex. Willd (Pteridaceae)

Chemical studies of green leaves of A. tetraphyllum afforded b-sitosterol, a mixture containing the ethyl esters of long chain carboxylic acids, 30-normethyl-lupan-20-one, hopan-22-ol, phytol, phyten-3(20)-1,2-diol, quercetin and quercetin-3-O-b-D-glucoside. The structures of the compounds were elucidated by spectroscopic and GC analysis. The allelopathic potentials of the crude ethanolic extract and fractions were evaluated against Lactuca sativa (letuce) and Allium cepa (onion) seeds.

Bioactivity and Chemical Composition of the Essential Oils of Croton urucurana Baillon (Euphorbiaceae)

Abstract The essential oils from the stem barks and leaves of Croton urucurana Baillon (Euphorbiaceae) were analyzed by GC-FID and GC-MS. 100 compounds were identified and borneol (14.7 %), bornyl acetate (5.2 %), cadina-4,10(14)-dien-1α-ol (14.7 %), sesquicineole (10.5 %) and γ-gurjunene epoxide (5.4 %) were the main components in essential oil from the steam barks. The oil from leaves was rich in sesquiterpenoids,mainly germacrene-D (15.2 %) and bicyclogermacrene (36.4 %). The in vitro cytotoxicity of the oils was evaluated against nine cancer cell lines and herbicidal effects against two seeds. The antimicrobial and antioxidant activities of the oils also were evaluated. The essential oil of stem bark was found to be more active than oil from leaves.