Sônia Corina Hess

Anti-allodynic action of the tormentic acid, a triterpene isolated from plant, against neuropathic and inflammatory persistent pain in mice.

Experiments were designed to address whether the pentacyclic triterpene tormentic acid isolated from the stem bark of the plant Vochysia divergens exerts oral anti-allodynic properties in two models of chronic pain in mice: neuropathic pain caused by partial ligation of the sciatic nerve and inflammatory pain produced by intraplantar injection of Complete Freunds Adjuvant. Oral administration of tormentic acid (30 mg/kg) twice a day for several consecutive days produced time-dependent and pronounced anti-allodynia effect in both ispsilateral and contralateral paws after plantar injection of Complete Freunds Adjuvant. The inhibition observed was 82+/-9% and 100+/-11%, respectively. Interestingly, tormentic acid did not inhibit paw oedema formation following Complete Freunds Adjuvant plantar injection. Tormentic acid (30 mg/kg, p.o.) and gabapentin (70 mg/kg, p.o.), given twice a day, inhibited markedly the neuropathic allodynia induced by partial ligation of the sciatic nerve, with inhibition of 91+/-19% and 71+/-16%, respectively. The anti-allodynic action of tormentic acid was not associated with impairment of the motor activity of the animals. Together, the present results indicate that tormentic acid or its derivatives might be of potential interest in the development of new clinically relevant drugs for the management of persistent neuropathic and inflammatory allodynia.

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.

6beta-hydroxymaslinic acid, a triterpene from Vochysia ferruginea

A novel oleane acid was isolated from the leaves and the fruits of Vochysia ferruginea. The structure of the new triterpenoid was elucidated by NMR spectroscopy as 2a,3b,6b-trihydroxyolean-12-en-28-oic acid (6b-hydroxymaslinic acid, 1). In addition, b-sitosterol-glucoside and three mixtures containing known triterpenoids, uvaol and erythrodiol, ursolic and oleanolic acids, 2a,3b-dihydroxyurs-12-en-28-oic acid and its respective oleanolic isomer (maslinic or crategolic acid), were isolated from the leaves and the fruits of Vochysia ferruginea. In the fruits, bellericagenin A and its (28 ® 1) b-D-glucopyranosyl ester (bellericaside A) were present in high amount.

Divergioic Acid, a Triterpene from Vochysia divergens

A new lupane triterpene, divergioic acid, has been isolated from the stem bark of Vochysia divergens together with b-sitosterol, betulinic, sericic and 24-hydroxytormentic acids and the (28 ® 1) b-D-glucopyranosyl ester of the latter. The structure of divergioic acid was elucidated by spectroscopic techniques and characterized as 2a,3b,6b-trihydroxy-lup-20(29)-en-28-oic acid.

Jatrowedione, a lathyrane diterpene from Jatropha weddelliana

Abstract 3-Acetylaleuritolic acid, sitosterol and a novel lathyrane diterpene, jatrowedione, have been isolated from the roots of Jatropha weddelliana . The elucidation of the structure of the latter was accomplished by detailed NMR investigation, and the relative configuration was established by difference NOE experiments.

Acyl lupeols from Cnidoscolus vitifolius

Abstract In addition to 3-acetyl aleuritolic acid, 3β-acetyl-, cinnamoyl-, dihydrocinnamoyl-lupeol, a new ester of lupeol has been isolated from the stems of Cnidoscolus vitifolius. Its structure was established to be 3β-hexanoyl lupeol by spectroscopic methods.

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.