4,5-Seco-Guaiane and a Nine-Membered Sesquiterpene Lactone from Holostylis reniformis

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Helivypolide G. A novel dimeric bioactive sesquiterpene lactone

Helivypolide G was isolated from leaves of Helianthus annuus L. cv. Stella. In the course of our ongoing research for new allelochemicals from Helianthus annuus, a novel dimeric bioactive sesquiterpene lactone, helivypolide G has been isolated and characterized from the medium polar active fractions of the leaves of cultivar variety Stella. The monomers are connected through carbons C-15 of each unit and an oxygen bridge, forming an enolic oxane ring. © 2004 Elsevier Ltd. All rights reserved.

Sesquiterpene lactones as allelochemicals

Six new sesquiterpene lactones, annuolide H ( 3), helivypolides F, H-J ( 4, 11-13), and helieudesmanolide A ( 6), together with known compounds, were isolated from polar bioactive fractions of Helianthus annuus cv. SH-222 and Stella fresh leaf water extracts. Spectroscopic analysis of the new data for 1,2-anhydroniveusin A and 1-methoxy-4,5-dihydroniveusin A corrects some previous assignments. The compounds were tested using the etiolated wheat coleoptile bioassay, and the most active compounds were assayed in standard target species ( STS) ( Lepidium sativum, Allium cepa, Lactuca sativa, Lycopersicon esculentum, and Triticum aestivum) from 5 x 10(-4) to 10(-5) M. The most phytotoxic compounds were helivypolide F and 15-hydroxy-3-dehydrodeoxyfruticin, both of which have a carbonyl group at C-3 conjugated with two double bonds.

Comparison of the gastroprotective effect of a diterpene lactone isolated from Croton cajucara with its synthetic derivatives

The effect of three new derivatives from dehydrocrotonin (DHC-compound I) on gastric damage indifferent animal models including gastric ulceration induced by a necrotic agent and hypothermic restrained-stress was studied: compound 11 (produced by reducing the cyclohexenone moiety of DHC with NaBH4): compound III (produced by reducing the carbonyls with LiAlH4); and compound IV (produced by transforming the lactone moiety into an amide). Their structures were confirmed on the basis of chemical and physicochemical evidence. When previously administered (p.o.) at a dose of 100 mg/kg, compound II significantly (P < 0.01) reduced gastric injury induced by HCl/ethanol (78%) and indomethacin (88%) better than did reference compound 1 (48 and 43%, respectively). But the anti-ulcerogenic activity of compound II was completely abolished by the stress-induced ulcer. Reduction of carbonyls with LiAlH4 (compound 111) caused decreased activity, markedly when no protective effect in any of the models was applied (P > 0.05). However, compound IV, in which the lactone moiety was changed into an amide. when administered at the same dose (100 mg/kg, p.o.), was more effective. The presence of a lactone moiety or Michael acceptor is probably essential for the anti-ulcerogenic effect of these compounds. (C) 2003 Elsevier B.V. Ireland Ltd. All rights reserved.

Antiprotozoal Sesquiterpene Pyridine Alkaloids from Maytenus ilicifolia

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A DNA-damaging sesquiterpene and other constituents from Frullania nisquallensis

Bioassay-guided fractionation of an MeCOEt extract of Frullania nisquallensis Sull. has furnished a DNA-damaging sesquiterpene, costunolide (1), and two inactive compounds, a sesquiterpene (-)-frullanolide (2) and a tridepside tenuiorin (3). C-13-NMR data of 3 are reported.

Bioactive sesquiterpene pyridine alkaloids from Maytenus aquifolium

Two new sesquiterpene evoninate alkaloids, were isolated together with the known compounds syringaresinol and 4'-O-methyl-(-)-epigallocatechin from the root bark of Maytenus aquifolium. The structures of the two alkaloids were elucidated by interpretation of their spectral data, and both exhibited very weak activity in a mechanism-based DNA-modifying yeast assay. (C) 1998 Elsevier B.V. Ltd. All rights reserved.

Further sesquiterpene pyridine alkaloids from Maytenus aquifolium

Two new sesquiterpene evoninate alkaloids, aquifoliunine E-III and aquifoliunine E-IV, were isolated from the root bark of Maytenus aquifolium. The structures of the new compounds were elucidated on the basis of spectroscopic methods, including ES-MS.

Quantitative HPLC analysis of sesquiterpene lactones and determination of chemotypes in Eremanthus seidelii MacLeish & Schumacher (Asteraceae)

Eremanthus seidelii MacLeish & Schumacher has a restricted occurrence to the Brazilian cerrado surrounding the Furnas (MG) reservoir, in environments that have been seriously damaged by human activity. The present phytochemical investigation reveals that the sesquiterpene lactones (SL) 4β,5-dihydro-2′,3′-dihydroxy-15-desoxy-goyazensolide (1) and 4β,5-dihydro-1′,2′-epoxy-eremantholide-C (2) are the major secondary metabolites in E. seidelii leaves, and an HPLC method was developed for their quantitative analysis. HPLC analysis showed no significant seasonal variation in the concentrations of both SL. No qualitative differences were found in the SL patterns of all individuals sampled. However, there is a different SL quantitative pattern among the plants analyzed, pointing to the existence of three quantitative chemotypes of this species, with differences possibly originating from the activity of the enzymes that cyclize the goyazensolide type SL (1) to a eremantholide type SL (2). ©2005 Sociedade Brasileira de Química.

Anti-inflammatory intestinal activity of Arctium lappa L. (Asteraceae) in TNBS colitis model

Ethnopharmacological relevance: In Brazilian traditional medicine, Arctium lappa (Asteraceae), has been reported to relieve gastrointestinal symptoms. Aim of the study: In the present study, we investigated the effects of the lactone sesquiterpene onopordopicrin enriched fraction (ONP fraction) from Arctium lappa in an experimental colitis model induced by 2,4,6 trinitrobenzene sulfonic acid and performed experiments to elucidate the underlying action mechanisms involved in that effect. Materials and methods: ONP fraction (25 and 50 mg/kg/day) was orally administered 48, 24 and 1 h prior to the induction of colitis and 24 h after. The inflammatory response was assessed by gross appearance, myeloperoxidase (MPO) activity, tumor necrosis factor alpha (TNF-α) levels and a histological study of the lesions. We determined cyclooxygenase (COX)-1 and -2 protein expressions by western blotting and immunohistochemistry assays. Results: TNBS group was characterized by increased colonic wall thickness, edema, diffuse inflammatory cell infiltration, increased MPO activity and TNF-α levels. On the contrary, ONP fraction (25 and 50 mg/kg) treatment significantly reduced the macroscopic inflammation scores (p<0.05 and p<0.01, respectively) and morphological alterations associated with an increase in the mucus secretion. Similarly, the degree of neutrophil infiltration and the cytokine levels were significantly ameliorated. Moreover, COX-2 expression was up regulated in TNBS-treated rats. In contrast, ONP fraction (50 mg/kg) administration reduced COX-2 overexpression. Conclusions: We have shown that the ONP fraction obtained from Arctium lappa exert marked protective effects in acute experimental colitis, confirming and justifying, at least in part, the popular use of this plant to treat gastrointestinal diseases. © 2013 Elsevier B.V. All rights reserved.

Composition and acaricidal activity of the essential oil of Lychnophora ericoides Mart. to Tetranychus urticae Koch (Acari: Tetranychidae).

The essential oil of the leaves and branches obtained by hydrodistillation of Lychnophora ericoides, collected in the Reserve of Furnas - MG, Brazil, was analyzed by CG/EM (Shimadzu QP2010). The major parts of the volatile components identified in the essential oil of leaves were monoterpenes (44.02%) and the sesquiterpene [alpha]-bisabolol (2.05%). The major acaricidal activity of the essential oil from L. ericoides was observed at 48 (14.55 [mu]L/L of air) and 72 h (8.01 [mu]L/L of air) of exposition. The oviposition of T. urticae oviposition was influenced by the essential oil, but the eclosion of eggs was not affected.

Biological effects of Ocimum gratissimum L. are due to synergic action among multiple compounds present in essential oil

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Effect of Baccharis dracunculifolia DC (Asteraeeae) extracts and its isolated compounds on macrophage activation

Baccharis dracunculifolia D.C. (Asteraceae), a shrub which grows wild in Brazil, is the main botanical source of Brazilian green propolis. Since Brazilian propolis shows an immunomodulatory activity, the goal of this work was to evaluate the action of B. dracunculifolia extracts and some of its isolated compounds on reactive oxygen intermediate (H2O2) production by macrophages obtained from male BALB/c mice. The results showed that the leaf (Bd-L) (25, 50, and 100 mu g mL(-1)), leaf rinse (Bd-LR) (25 mu g mL(-1)), and the root (Bd-R) (25 mu g mL(-1)) extracts enhanced H2O2 release by macrophages. A phytochemical study of the root and leaves of B. dracunculifolia was carried out. The chromatographic fractionation of Bd-R, using several techniques, afforded the isolation of baccharis oxide (1), friedelanol (2), viscidone (11), 11-hydroxy-10,11-dihydro-euparin (12), and 6-hydroxy-tremetona (13), while Bd-LR gave the following isolated compounds: baccharis oxide (1), friedelanol (2), isosakuranetin (3), aromadendrin-4'-methyl ether (4), dihydrocumaric acid (5), baccharin (6), hautriwaic acid lactone (7), hautriwaic acid acetate (8), drupanin (9), and cumaric acid (10). Among the isolated compounds, baccharis oxide (1) and friedelanol (2) increased H2O2 production at a concentration of 1001,M. This is the first time that the presence of compounds 7, 8, 12, and 13 in B. dracunculifolia has been reported. Based on these results it is suggested that the crude extracts and some isolated compounds from B. dracunculifolia display an immunomodulatory action.

Moxidectin-resistant nematodes in cattle in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determination of the LC50 of selamectin (active principle of the antiparasitic Revolution (R), Pfizer) applied on engorged female of the tick Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)