Euclésio Simionatto

Volatile compounds of leaves and fruits of Mangifera indica var. coquinho (Anacardiaceae) obtained using solid phase microextraction and hydrodistillation.

Volatile compounds present on fruits and leaves of Mangifera indica var. coquinho were investigated by headspace solid phase microextraction (HS-SPME) and hydrodistillation (HD). Conventional techniques, such as hydrodistillation, may impart chemical changes to the original oil composition being also time-consuming. On the other hand, HS-SPME provides solvent-less extractions, shorter extraction times and may supply complementary information about the composition of the compounds. The HS-SPME technique was previously evaluated by the comparative study among the fibres: commercial PDMS, NiTi-ZrO(2) and NiTi-ZrO(2)-PDMS. The fibre NiTi-ZrO(2)-PDMS showed better sensitivity and precision and was used on the extraction of components. The influence of several parameters like the time and temperature of extraction and desorption time were examined to obtain better efficiency. Fruits and leaves were analysed in mature and immature stages. The profiles corresponding to the volatile compounds detected by both techniques are discussed.

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.

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.

Chemical composition and antimicrobial activity of the essential oil from Aeolanthus suaveolens Mart. ex Spreng

The essential oils from leaves (sample A) and flowers (sample B) of Aeolanthus suaveolens Mart. ex Spreng were obtained by hydrodistillation and analyzed by GC, GC-MS, and chiral phase gas chromatography (CPGC). Six compounds have been identified from the essential oils, representing ca 94.3 and 93% of the oils corresponding to samples A and B, respectively. The major constituents of samples A and B essential oils were respectively, linalool (34.2%/34.9%), (-)-massoialactone (25.9%/17.0%) and (E)-b-farnesene (25.4%/29.1%). The enantiomeric distribution of the monoterpene linalool was established by analysis on heptakis- (6-O-methyl-2,3-di-O-pentyl)-b-cyclodextrin capillary column. The antimicrobial activity of the essential oil from leaves and isolated compounds was also evaluated.

Chemical Composition and Biological Activities of Leaves Essential Oil From Schinus molle (Anacardiaceae)

Abstract The essential oil of Schinus molle (Anacardiaceae) obtained by hydrodistillation from the aerial parts, was analyzed by gas chromatography (GC), GC-mass spectrometry (MS) and nuclear magnetic resonance (NMR). The oil contains 69.1 % of sesquiterpenes and 20 % of monoterpenes. The most abundant essential oil components were 1,8-cineole (7.6 %), terpin-4-ol (6.1 %), epi-a-cadinol (27.3 %), caryophyllene oxide (10.5 %), y-cadinene (9.1 %), spathulenol (8.6 %), 1,10-di-epi-cubenol (4.4 %) and 7-epi-a-eudesmol (2.3 %). The leaf essential oil showed pronounced in-vitro cytotoxic activity against K562 (0.89 μg/mL) and NCI-ADR/RES (3.40 μg/mL) human tumor cell lines. The antimicrobial, antioxidant and allelophathic activities of essential oil were also evaluated.

Estudos químicos e biológicos de Microgramma vacciniifolia (Langsd. & Fisch.) Copel (Polypodiaceae)

Chemical studies with aerial parts of Microgramma vacciniifolia (Langsd. & Fisch.) Copel. afforded ²-sitosterol, hopan-22-ol, 6-metoxiapinenin-7-O-²-D-allopyranoside and a mixture containing ethyl esters of carboxilic acids. The structures of the coumpounds were elucidated by spectroscopy and GC-MS analysis. The total phenolics contents of the crude extract and fractions were determined by Folin-Ciocalteau method. The antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH). The AcOEt fraction showed better activity in DPPH assay (9.9 ± 0.03 µg/mL), and presented also higher contents of the total phenolic (93.60 ± 1.11 µg/mg). Antimicrobial and allelopathic effects of the crude etanolic extract and fractions also were evaluated. In addition, the combination of biological activities was discussed.

Chemical Composition and Cytotoxic Activity of Leaves Essential Oil from Mangifera indica var. coquinho (Anacardiaceae)

Abstract The volatile composition of Mangifera indica var. coquinho has been studied. The essential oils were obtained by hydrodistillation in a modified Clevenger-type apparatus, and their analyses were performed by GC-FID and GC/MS. A total of 19 different compounds were identified. Sesquiterpene hydrocarbons were shown to be the main group of constituents of all taxa. The main constituents of the oil were α-gurjunene (24.0%), β-selinene (24.0%), β-caryophyllene (11.2%), α-humulene (7.2%), caryophyllene oxide (5.5%) and humulene epoxide (2.4%). The cytotoxic activity of the oil was more pronounced than antioxidant and antimicrobial activities.

Potencial fitotóxico de Dicranopteris flexuosa (Schrad.) Underw. (Gleicheniaceae)

This work aimed to determine the phytotoxic potential of crude ethanol extract and semipurified fractions of Dicranopteris flexuosa on the germination and growth of Lactuca sativa L. (lettuce), Lycopersicon esculentum L. (tomato), Allium cepa L. (onion) and Triticum aestivum L. (wheat) in laboratory and greenhouse bioassays and determine total phenolic and flavonoid content. For the tests carried out in laboratory, four concentrations (0, 250, 500, 1000 mg.L-1) were applied to four replicates of 50 seeds each. Analysis of the results indicates a reduction in speed and/or inhibition of germination, stimulation of root growth in eudicots and root inhibition in the monocots studied. For the bioassays carried out in the greenhouse, the plant materials were applied at the same concentrations as those in the laboratory bioassays, with eight replicates of five seeds each. Analysis of the results indicates that root length was affected by the crude ethanol extract resulting in stimulation in tomato and inhibition in onion and wheat. Aerial dry mass was higher at the lower concentration in lettuce and wheat. The ethyl acetate fraction presented higher content of total phenols and flavonoids. Although the results are preliminary, they indicate that ethanol extract and semipurified fractions of D. flexuosa contain substances that modify seedling growth of lettuce, tomato, onion and wheat.