Anti-Leishmania effect of icetexanes from Salvia procurrens.

BACKGROUND AND PURPOSE: Leishmaniasis is a globally prevalent vector-borne disease caused by parasites of the genus Leishmania. The available chemotherapeutic drugs present problems related to efficacy, emergence of parasite resistance, toxicity and high cost, justifying the search for new drugs. Several classes of compounds have demonstrated activity against Leishmania, including icetexane-type diterpenes, previously isolated from Salvia and other Lamiaceae genera. Thus, in this study, compounds of Salvia procurrens were investigated for their leishmanicidal and immunomodulatory activities. METHODS: The exudate of S. procurrens was obtained by rapidly dipping the aerial parts in dichloromethane. The compounds were isolated by column and centrifugal planar chromatography over silica gel. The effects on L. amazonensis growth, survival, membrane integrity, reactive oxygen species (ROS) generation, mitochondrial membrane potential and cytotoxicity of the compounds towards human erythrocytes, peripheral blood mononuclear cells and macrophages were evaluated. The effects on intracellular amastigote forms, nitric oxide (NO) and TNF-α production were also investigated. RESULTS: The exudate from the leaves afforded the novel icetexane 7-hydroxyfruticulin A (1) as well as the known demethylisofruticulin A (2), fruticulin A (3) and demethylfruticulin A (4). The compounds (1-4) were tested against promastigotes of L. amazonensis and showed an effective inhibition of the parasite survival (IC50 = 4.08-16.26 µM). In addition, they also induced mitochondrial ROS production, plasma membrane permeability and mitochondrial dysfunction in treated parasites, and presented low cytotoxicity against macrophages. Furthermore, all diterpenes tested reduced the number of parasites inside macrophages, by mechanisms involving TNF-α, NO and ROS. CONCLUSION: The results suggest the potential of 7-hydroxyfruticulin A (1) as well as the known demethylisofruticulin A (2),fruticulin A (3) and demethylfruticulin A (4) as candidates for use in further studies on the design of anti-leishmanial drugs.

Anthraquinones from the bark of Senna macranthera

2-acetyl physcion (2-acetyl-1,8-dihydroxy-6-methoxy-3-methyl-9,10-anthraquinone, 2), a rare anthraquinone, was isolated from Senna macranthera var. nervosa (Vogel) H.S. Irwin & Barneby (Fabaceae). The chemical structure was elucidated and all ¹H and 13C NMR chemical shifts were assigned by NMR one- (¹HNMR, {¹H}-13CNMR, and APT-13CNMR) and two (COSY, NOESY, HMQC and HMBC) dimensional of this natural compound. Furthermore, the minor anthraquinones chrysophanol (3), chrysophanol-8-methyl ether (4) and physcion (5) were characterized by GC-MS analysis. The occurrence of the anthraquinones 3-5 confirms that S. macranthera is a typical representative of the genus Senna.

2-acetil-fisciona (2-acetil-1, 8-di-hidróxi-6-metóxi-3-metil-9, 10-antraquinona, 2), uma antraquinona rara, foi isolada de Senna acranthera var. nervosa (Vogel) H.S. Irwin & Barneby (Fabaceae). estrutura química foi elucidada e todos os deslocamentos químicos de RMN ¹H e 13C foram atribuídos através de RMN uni- (RMN¹H, {¹H}-RMN-13C e APT-RMN13C) e bi- (COSY, NOESY, HMQC e HMBC) dimensional deste composto natural. Adicionalmente, as antraquinonas minoritárias crisofanol (3), crisofanol-8-metil éter (4) e fisciona (5) foram caraterizadas pela análise de CG-EM. A ocorrência das antraquinonas 3-5 confirma que S. macranthera é uma típica representante do gênero Senna.

Antioxidant activity from the leaf extracts of Jacaranda puberula Cham., Bignoniaceae, a Brazilian medicinal plant used for blood depuration / Atividade antioxidante do extrato das folhas de Jacaranda puberula Cham., Bignoniaceae, uma planta medicinal Brasileira usada como depurativo do sangue

The antioxidant activity of leaf extracts from Jacaranda puberula Cham., Bignoniaceae, was assayed by the DPPH (2,2-diphenyl-1-picryl-hydrazyl) free radical scavenging method. Three phytomedicines (F1, F2, and F3) used as blood depurative, were tested by the same method. The free radical scavenger potential was measured by the discoloration of the solution. The EC50 values from Gingko bilobaEGb 761® extract and rutin, used as antioxidant for medical purposes, were used as reference. The ethanol extract (EE), ethyl acetate (EA), butanol (EB), aqueous (EAq) and the sample A (obtained from extract EB), showed lower EC50 values than other extracts and phytomedicines. The antioxidant activity (AA) of the extracts was related with the presence of the polyphenol compounds such as verbascoside (1) and cis-caffeoyl aldehyde (2). These structures were determined by chemical and spectroscopic methods and comparison with literature data.

Os extratos obtidos a partir das folhas de Jacaranda puberulaCham., Bignoniaceae, foram avaliados quanto à atividade antioxidante utilizando-se o método do radical livre DPPH (2,2-difenil-1-picril-hidrazila). Também foram incluídos na avaliação três medicamentos fitoterápicos comerciais (F1, F2 e F3) indicados como depurativos do sangue. Através da descoloração das soluções testadas, foi possível medir o potencial sequestrador do radical DPPH. Como referência, utilizou-se os dados da literatura de CE50 do extrato padronizado de Gingko bilobaEGb 761® e o flavonoide rutina, ambos empregados em medicamentos com atividade antioxidante. Entre os extratos testados, os que apresentaram valores baixos de CE50 foram os extratos etanólico bruto (EE), em acetato de etila (EA), em butanol (EB), aquoso (EAq) e da amostra A, obtida do extrato EB. Os fitoterápicos comerciais apresentaram altos valores de CE50. Com base nos resultados das análises feitas por de RMN de 13C e ¹H, CLAE-DAD e de acordo com os dados da literatura, a presença de substâncias fenólicas como o verbascosídeo (1) e o aldeído cis-caféico (2), contribuíram para a atividade antioxidante (AA) dos extratos ativos.

Complete ¹H and 13C NMR assignments and anti fungal activity of two 8-hydroxy flavonoids in mixture

A mixture of the two new flavonols 8-hydroxy-3, 4', 5, 6, 7-pentamethoxyflavone (1) and 8-hydroxy-3, 3', 4', 5, 6, 7-hexamethoxyflavone (2) was isolated from a commercial sample of Citrus aurantifolia. An array of one- (¹HNMR, {¹H}-13C NMR, and APT-13C NMR) and two-dimensional NMR techniques (COSY, NOESY, HMQC and HMBC) was used to achieve the structural elucidation and the complete ¹H and 13C chemical shift assignments of these natural compounds. In addition, the antifungal activity of these compounds against phytopathogenic and human pathogenic fungi was investigated.

Os flavonóis 8-hidroxi-3, 4', 5, 6, 7-pentametoxiflavona (1) e 8-hidroxi-3, 3', 4', 5, 6, 7-hexametoxiflavona (2) foram isolados em mistura a partir de uma amostra comercial de Citrus aurantifolia. A determinação estrutural e a inequívoca atribuição dos sinais de deslocamento químico dos átomos de hidrogênio e carbono destes compostos naturais foram realizadas através da análise dos espectros de RMN 1D e 2D, incluindo COSY, NOESY, HMQC e HMBC. Em adição, a atividade antifúngica destes compostos contra fungos patogênicos também foiinvestigada.

Antimicrobial activity of wax and hexane extracts from Citrus spp. peels

Antibacterial and antifungal properties of wax and hexane extracts of Citrus spp. peels were tested using bioautographic and microdilution techniques against three plant pathogenic fungi (Penicillium digitatum, Curvularia sp., and Colletotrichum sp.), two human pathogens (Trichophyton mentagrophytes and Microsporum canis), and two opportunistic bacteria (Escherichia coli and Staphylococcus aureus). Two polymethoxylated flavonoids and a coumarin derivative, were isolated and identified from peel extracts, which presented antimicrobial activity especially against M. canis and T. mentagrophytes: 4',5,6,7,8-pentamethoxyflavone (tangeritin) and 3',4',5,6,7,8-hexamethoxyflavone (nobiletin) from C. reticulata; and 6,7-dimethoxycoumarin (also known as escoparone, scoparone or scoparin) from C. limon.

Flavonóides O-glicosilados de Croton campestris St. Hill. (Euphorbiaceae) / Glycosyl flavonoids from Croton campestris St. Hill. (Euphorbiaceae)

Do extrato butanólico de Croton campestris St. Hill. (Euphorbiaceae) foram isolados quatro flavonóides, todos O-glicosídeos da quercetina. Estas substâncias foram identificadas como 3-O-b-D-apiofuranosil-(1®2)-galactopiranosil quercetina (1), 3-O-b-D-galactopiranosil quercetina (hiperina) (2), 3-O-a-L-arabinopiranosil quercetina (guaijaverina) (3) e 3-O-a-L-ramnopiranosil quercetina (quercitrina) (4).O presente trabalho relata a presença destas substâncias pela primeira vez para esta espécie de Croton, cuja elucidação estrutural deu-se por espectroscopia em UV, EM e RMN, incluindo as técnicas bidimensionais: ¹H-¹H (2D NOESY, 2D COSY), ¹H-13C (2D HETCOR) e 13C (APT), além de comparações com os dados da literatura.

Four flavonoids were isolated from the butanolic extract of the aerial parts of Croton campestris St. Hill. (Euphorbiaceae). These compounds were identified as 3-O-b-D-apiofuranosyl-(1®2)-galactopyranoside quercetin (1), 3-O-b-D-galactopyranoside quercetin (hyperin) (2), 3-O-a-L-arabinopyranoside quercetin (guaijaverin) (3) and 3-O-a-L-ramnopyranoside quercetin (quercitrin) (4). They have been isolated for the first time from Croton campestris. Their structures were elucidated by UV, MS and NMR experiments including ¹H-¹H (2D NOESY, 2D COSY), ¹H-13C (2D HETCOR), 13C (APT) and by comparison of the spectral data with those reported in the literature.