Vanessa Gregório Rodrigues

Chemical composition and fumigant effect of essentialoil of Lippia sidoides Cham. and monoterpenes against Tenebrio molitor (L.) (coleoptera: tenebrionidae)

A composicao quimica do oleo essencial de Lippia sidoides obtido por hidrodestilacao foi caracterizada e quantificada por GC/MS, bem como sua atividade inseticida por teste de fumigacao foi avaliada sobre Tenebrio molitor. Alem disso, a toxicidade dos monoterpenos carvacrol, 1,8-cineol e timol, tambem foi avaliada quando esses compostos foram aplicados isoladamente, ou em misturas binarias (1:1), ou terciarias (1:1:1). O oleo essencial de L. sidoides tem como principais constituintes o carvacrol (31,68%), ρ-cimeno (19,58%), 1,8-cineol (9,26%) e ϒ-terpineno (9,21%), em 21 compostos identificados, sendo 92,53% do total. Ambos os compostos possuem atividade inseticida contra T. molitor, seguindo a ordem de toxicidade: carvacrol > 1,8-cineol > oleo essencial de L. sidoides > timol; sendo suas respectivas CL50 a 24 h de 5,53; 5,71; 8,04 e 14,71 µL/L ar. Quando as diferentes misturas de carvacrol, 1,8-cineol e timol foram avaliadas contra T. molitor, verificou-se o efeito sinergico. Para a mistura de carvacrol:1,8-cineol a CL50 foi de 5,34 µL/L ar; carvacrol:timol de 7,67 µL/L ar; 1,8-cineol:timol de 7,51 µL/L ar e carvacrol:1,8-cineol:timol de 6,34 µL/L ar. Principalmente o monoterpeno timol teve efeito sinergico, aumentando a toxicidade de carvacrol e 1,8-cineol quando em misturas binarias, tais como carvacrol:timol e 1,8-cineol:timol.

Atividade inseticida do óleo essencial de pimenta longa (Piper hispidinervum C. DC.) sobre lagarta-do-cartucho do milho Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae)

The objectives of this research were to evaluate the chemical composition and bioactivity of the essential oil from the longpepper leaves (Piper hispidinervum) and its effect on the comportment and/or mortality of the fall armyworm (Spodoptera frugiperda). The essential oil was obtained by steam stream distillation, using the modified Clevenger apparatus, the chemical composition was analyzed by GC-MS and GC. Tests of ingestion and topical application in fall armyworm of 1 st and 3 rd instar were made. The results showed that the long-pepper essential oil has insecticide activity on S. frugiperda, causing mortality and food reduction, and safrole (82%) as its majority constituent. Mortality was found in the ingestion test in larvae of 1 st instar LC 50 = 16.2 mg/mL for larvae of 3 rd instar LC 50 = 9.4 mg/mL, with reduced food CD 50 = 0.72 mg/mL; and acute toxicity test of the contact topic with LD 50 = 277.91 μg/larvae, after an interval of 96 hours, neurotoxicity symptoms were also observed, as knock-down effect.

Evaluation of antimicrobial activity and toxic potential of extracts and triterpenes isolated from Maytenus imbricata

The phytochemical study of hexane/ethyl ether (1:1) extract of the roots of M. imbricata, Celastraceae, resulted in the isolation and characterization of six known triterpenes: 11α-hydroxylup-20(29)-en-3-one, previously isolated from this species besides, 3β,11α-di-hydroxylup-20(29)-ene, 3,7-dioxofriedelane, 3-oxo-29-hydroxyfriedelane, tingenone and 6-oxo-tingenol. The chemical structures of these triterpenes were established by spectrometric data (IR, 1H and 13C NMR) and through comparison with literature data. The hexane/ethyl ether (1:1), ethyl acetate and methanol extracts, and 11α-hydroxylup-20(29)-en-3-one, tingenone and 6-oxo-tingenol, showed antimicrobial properties on in vitro assays. All extracts and triterpenes, except 3β,11α-di-hydroxylup-20(29)-ene, presented toxicity demonstrated by the larvicidal effect test using Artemia salina.

Tingenone, a Pentacyclic Triterpene, Induces Peripheral Antinociception Due to Opioidergic Activation

Plants belonging to the genus Maytenus are routinely used in folk medicine for the treatment of pain diseases. Our previous phytochemical study of the roots of Maytenus imbricata resulted in the isolation and characterization of tingenone, a pentacyclic triterpene. Natural triterpenoids are of growing interest because they have several biological activities, including analgesic properties. The present study assessed the involvement of the opiodergic pathway in the tingenone-induced antinociceptive effect against hyperalgesia induced by prostaglandin E2 (2 µg) in the peripheral pathway. We evaluated the effect of several antagonists to opioid receptors using the mouse paw pressure test. Tingenone administered into the right hind paw induced a local antinociceptive effect that was antagonized by naloxone, a nonselective antagonist to opioid receptors. Clocinnamox, naltrindole, and nor-binaltorphimine are selective antagonists to µ, δ, and κ receptors, respectively, which reverted the peripheral antinociception induced by tingenone. Bestatine acts as an inhibitor of aminopeptidase, an enzyme that degrades endogenous opioid peptides, and was shown to intensify the antinociceptive effect of tingenone. The results suggest that the opioidergic system participates in the peripheral antinociception induced by tingenone.

Salacia crassifolia (Celastraceae): CHEMICAL CONSTITUENTS AND ANTIMICROBIAL ACTIVITY

3-oxofriedelane, 3β-hydroxyfriedelane, 3-oxo-28-hydroxyfriedelane, 3-oxo-29-hydroxyfriedelane, 28,29-dihydroxyfriedelan-3-one, 3,4-seco-friedelan-3-oic acid, 3β-hydroxy-olean-9(11):12-diene and the mixture of α-amirin and β-amirin. β-sitosterol, the polymer gutta-percha, squalene and eicosanoic acid were also isolated. The chemical structures of these constituents were established by IR, 1H and 13C NMR spectral data. Crude extracts and the triterpenes were tested against Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis and no activity was observed under the in vitro assay conditions. The hexane, chloroform, ethyl acetate and ethanol crude extracts, and the constituent 3,4-seco-friedelan-3-oic acid and 28,29-dihydroxyfriedelan-3-one showed in vitro antimicrobial activity against Salmonella typhimurium, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Streptococcus sanguinis and Candida albicans.

Tingenone, a pentacyclic triterpene, induces peripheral antinociception due to NO/cGMP and ATP-sensitive K+ channels pathway activation in mice

Substances derived from plants play an important role in the development of new analgesic drugs, among them, triterpenoids. The connection between the participation of L-arginine/NO/cGMP pathway and the activation of ATP-sensitive K(+) channels (KATP) has been established on the peripheral antinociception induced by various drugs. The study assessed the involvement of L-arginine/NO/cGMP/KATP pathway in the antinociceptive effect induced by tingenone, from Maytenus imbricata, against the hyperalgesia evoked by prostaglandin E2 (PGE2) in peripheral pathway. The paw pressure test was used, with hyperalgesia induced by intraplantar injection of PGE2 (2 μg). Tingenone (200 µg/paw) administered into the right hind paw induced a local antinociceptive effect, that was antagonized by l-NOArg, nonselective nitric oxide synthase (NOS) inhibitor and by L-NPA, selective neuronal NOS (nNOS) inhibitor. The L-NIO, selective inhibitor of endothelial (eNOS), and the L-NIL, selective inhibitor of inducible (iNOS), did not alter the peripheral antinociceptive effect of the tingenone. The ODQ, selective soluble guanylyl cyclase inhibitor, prevented the antinociceptive effect of tingenone, and zaprinast, inhibitor of the phosphodiesterase that is cyclic guanosine monophosphate (cGMP) specific, intensified the peripheral antinociceptive effect of the smaller dose of tingenone. Glibenclamide, ATP-sensitive K(+) channels (KATP) blocker, but not tetraethylammonium chloride, voltage-dependent K(+) channel blocker; dequalinium dichloride, blocker of the small conductance Ca(2+)-activated K(+) channel, and paxilline, a potent blocker of high-conductance Ca(2+)-activated K(+) channels, respectively, prevented the peripheral antinociceptive effect of tingenone. The results demonstrate that tingenone induced a peripheral antinociceptive effect by L-arginine/NO/cGMP/KATP pathway activation, with potential for a new analgesic drug.

A new friedelane triterpenoid from the branches of Maytenus gonoclada (Celastraceae)

A new friedelane type triterpene, 3,16-dioxo-12α-hydroxyfriedelane was isolated from the chloroform extract of branches of Maytenus gonoclada Martius (Celastraceae) together with nine known compounds: 3, 11-dioxofriedelane, 3, 16-dioxofriedelane, 3, 12-dioxofriedelane, 3-oxo-12α,29-dihydroxyfriedelane, 3-oxofriedelane (friedelin), 3β-hydroxyfriedelane, 3-oxo-12α-hydroxyfriedelane and 3β-hydroxylup-20(29)-ene (lupeol) and a mixture of long chain hydrocarbons. The structure and stereochemistry of the new friedelane triterpene were established from the 1H NMR and 13C NMR spectra including two-dimensional experiments (HSQC, HMBC and NOESY) and high resolution mass spectrometry.

Triterpenes from Maytenus gonoclada and their attractive effects on Tenebrio molitor

Bioactive metabolites have been isolated from plants of the genus Maytenus (Celastraceae), such as maytansinoids with insecticide activity, sesquiterpene pyridine alkaloids with insect antifeedant activity, and nortriterpene quinonemethides, which show antimicrobial activity [1]. Despite the great diversity of plant metabolites showing several biological activities, no compound with the friedelane skeleton presenting attractive-repellent effects has been described until now [2]. Previous phytochemical studies with aerial parts of Brazilian Maytenus species showed mainly pentacyclic triterpenes (PCTT) of the friedelane series, which are regarded as the characteristic constituents of plants belonging to this genus. It is worth noting that the PCTT were identified as the principal constituents of some Brazilian Maytenus sp. Maytenus gonoclada Martius (Celastraceae), which can be found in the “cerrado” region and rupestrian fields of Southeast and Northeastern Brazil. It is a polymorphic tree, usually spiny, the spines sometimes end in short shoots. The leaves alternate and are extipulate. The flowers are hermaphrodite in axillary, solitary, or fascicled dichotomous cymes; the calix is 4-5-lobed. The petals are 4–5, spreading. The stamens are 4–5, inserted on the margin of the disc or slightly below it; the filaments are slender and broad [3]. In this work we report the isolation, from the aerial parts of M. gonoclada, of seven compounds of the friedelane series: 3-oxofriedelane (1) [4], 3 -hydroxyfriedelane (2) [5], 3,11-dioxofriedelane (3), 3,16-dioxofriedelane (4) [6], 3-oxo-12 -hydroxyfriedelane (5) [7], 3-oxo-28-hydroxyfriedelane (6) [8], and 3-oxo-29-hydroxyfriedelane (7) [9]; two members of the lupane series, 3 -stearyloxy-lup-20(29)-ene (8) and lupeol (9) [10]; a taraxane, 3 -taraxerol (10) [11]; two ursanes, -amyrin (11) [6] and 3 -stearyloxy-urs-12-ene (12) [12]; and oleanane -amyrin (13) [13]. -Sitosterol (14) [14], the polyol dulcitol or galactitol (15) [15], and palmitic acid (16) [16] were also chemically characterized. Two long-chain hydrocarbons with 28 and 36 carbons, respectively (17), were identified through high-resolution gas chromatography (GC). The hexane extract and constituents of M. gonoclada were tested for their attractive-repellent effects on the larvae of Tenebrio molitor (L.) (Coleoptera: Tenebrionidae). The hexane extract, the mixture of 3,11-dioxofriedelane and 3,16-dioxofriedelane, and the terpene 3-oxo12 -hydroxyfriedelane showed attractive effects on these larvae. Phytochemical studies demonstrated that the aerial parts of Brazilian Maytenus species consist mainly of triterpenes of the friedelane series, which are regarded as the characteristic constituents of plants belonging to this genus [2, 17]. It is worth noting that the pentacyclic triterpenes were identified as the principal constituents of Brazilian Maytenus sp. In the present work, we report the isolation of 13 known pentacyclic triterpenes: seven friedelanes (1–7), two lupanes (8 and 9), one taraxane (10), two ursanes (11 and 12), and the oleanane (13) obtained from M. gonoclada. Compounds 1 to 13 give a Liebermann–Buchard (LB) positive test for pentacyclic triterpenes, and 14 for steroids [18]. The 1H NMR spectra of constituents 1–7 showed a hydrogen signal at ~ H 0.87 (d, J = 6.8 Hz), which is in accord with the C-23 methyl group of members of the friedelane series. The 13C NMR data confirmed that compounds 1–7 are friedelane derivatives [6]. The 1H NMR spectra of compounds 8 and 9 showed signals at H 4.6 and H 4.7 that are characteristics of lupane triterpenes [19]. The presence of signals at C 150.98 and C 109.36 observed in 13C NMR spectra confirmed the lupane skeleton of these compounds [10].

Hydroethanolic extract of Pyrostegia venusta (Ker Gawl.) Miers flowers improves inflammatory and metabolic dysfunction induced by high-refined carbohydrate diet

ETHNOPHARMACOLOGICAL RELEVANCE Pyrostegia venusta is used in traditional Brazilian medicine as a general tonic to treat any inflammatory disease. Several studies have demonstrated that medicinal plants constitute a therapeutic approach for the treatment of obesity-related metabolic and inflammatory disarrangement. Accordingly, we investigated the effects of hydroethanolic extract of Pyrostegia venusta flowers (PvHE) supplementation for the treatment of inflammatory and metabolic dysfunction induced by high-refined-carbohydrate (HC) diet. MATERIAL AND METHODS The BALB/c mice were fed chow or HC diet for 8 weeks. Part of these animals was fed with HC diet supplemented with PvHE on the 9th week until the 12th week. At the end of the dietary intervention, animals were sacrificed. RESULTS We observed that PvHE decreased adiposity and adipocyte area; improved glucose intolerance; reduced serum triacylglycerol levels and systemic inflammatory cells; and also reduced some inflammatory mediators levels in adipose tissue and liver. CONCLUSION The results showed that PvHE has beneficial effects and may treat inflammatory and metabolic dysfunction induced by HC diet, that are associated to a negative modulation of the inflammatory process at systemic and local levels.

Antidiarrheal activity of extracts from Maytenus gonoclada and inhibition of Dengue virus by lupeol

Diarrhea is an infectious disease caused by bacterial, virus, or protozoan, and dengue is caused by virus, included among the neglected diseases in several underdeveloped and developing countries, with an urgent demand for new drugs. Considering the antidiarrheal potential of species of Maytenus genus, a phytochemical investigation followed by antibacterial activity test with extracts of branches and heartwood and bark of roots from Maytenus gonoclada were conducted. Moreover, due the frequency of isolation of lupeol from Maytenus genus the antiviral activity against Dengue virus and cytotoxicity of lupeol and its complex with β-cyclodextrins were also tested. The results indicated the bioactivity of ethyl acetate extract from branches and ethanol extract from heartwood of roots of M. gonoclada against diarrheagenic bacteria. The lupeol showed potent activity against Dengue virus and low cytotoxicity in LLC-MK2 cells, but its complex with β-cyclodextrin was inactive. Considering the importance of novel and selective antiviral drug candidates the results seem to be promising.