Zornioside, a dihydrochalcone C-glycoside, and other compounds from Zornia brasiliensis

ABSTRACT The secondary metabolites of the aerial parts of Zornia brasiliensis Vogel, Fabaceae, and the biological activity of one of these secondary metabolites were characterized in this study. A phytochemical investigation was performed using chromatographic techniques including analytical and preparative reverse-phase HPLC column sequences, which resulted in the isolation of fourteen compounds: one previously undescribed C-glycosylated dihydrochalcone (zornioside), one cyclitol (D-pinitol), one glycosylated megastigmane (roseoside) and eleven phenolic compounds: 7-methoxyflavanone, 7,4'-dimethoxyisoflavone, medicarpin, 2'-4'-dihydroxychalcone, onionin, isoorientin-3'-O-methyl ether, isovitexin, glycosylated (Z)-O-coumaric acid, glycosylated (E)-O-coumaric acid, dihydromelilotoside, and isoorientin. The structures of the isolated compounds were determined based on 1D and 2D-NMR, HRESIMS, IR and CD spectroscopic analyses. The cytotoxic activity of zornoside was assessed against tumor cell lines (MCF-7, HCC1954, T-47D, 4T1, HL60), and a non-tumor cell line (RAW264.7) using MTT assay. The compound zornioside was selectively cytotoxic for HL60 leukemia cells (IC50: 37.26 µM).

Toxicity and antitumor efficacy of Croton polyandrus oil against Ehrlich ascites carcinoma cells

ABSTRACT The essential oil from Croton polyandrus Spreng., Euphorbiaceae, leaves was tested for the toxicity and antitumor activity. The concentration producing 50% hemolysis was 141 µg/ml on mice erythrocytes. In the acute toxicological study, the estimated LD50 was 447.18 mg/kg. The essential oil did not induce increase in number of micronucleated erythrocytes, suggesting low genotoxicity. Essential oil (100 or 150 mg/kg) showed significant antitumor activity in Ehrlich ascitic carcinoma model. We observed that essential oil induces cell-cycle arrest at the G0/G1 phase, and increases the sub-G1 peak, which represents a marker of cell death by apoptosis. Survival also increased for the treated animals. The toxicological analyses revealed reduction in body weight, increased aspartate aminotransferase and alanine aminotransferase activity, hematological changes, and a thymus index reduction. These data suggest gastrointestinal and liver toxicity, anemia, leukopenia/lymphocytopenia, and immunosuppressive effects. Histopathological analysis revealed the weak hepatotoxicity of essential oil. In summary, essential oil of C. polyandrus displays in vivo antitumor activity and moderate toxicity.

Phytochemical study and antinociceptive effect of the hexanic extract of leaves from Combretum duarteanum and friedelin, a triterpene isolated from the hexanic extract, in orofacial nociceptive protocols

Combretum duarteanum Cambess, Combretaceae, is a plant widely distributed in Northeastern Brazil and, in folk medicine, stems and leaves are used for pain treatment. We investigated the antinociceptive effects of the hexanic extract of leaves from C. duarteanum and of friedelin, its main compound, in formalin-, glutamate- and capsaicin- induced orofacial nociception models. In order to isolate friedelin from the hexanic extract, flash chromatography technique was used. Male mice (n = 8/group) were pretreated with hexanic extract, friedelin, morphine or vehicle, before the injection of algogen agents into the right upper lip (perinasal area). The test of formalin-induced orofacial nociception showed that hexanic extract and friedelin significantly reduced nociception (p < 0.001) in both phases of testing. In the glutamate and capsaicin-induced orofacial nociception tests, pre-treatment with hexanic extract produced a significant reduction of orofacial nociception (p < 0.001) at all doses tested.The results suggest the hexanic extract and friedelin possess antinociceptive effects in models of orofacial nociception in rodents.

Xylodiol from Xylopia langsdorfiana induces apoptosis in HL60 cells

An atisane diterpene was isolated from Xylopia langsdorfiana St. Hilaire & Tulasne, Annonaceae, leaves, ent-atisane-7α,16α-diol (xylodiol). Preliminary study showed that xylodiol was cytotoxic and induced differentiation on human leukemia cell lines. However, the molecular mechanisms of xylodiol-mediated cytotoxicity have not been fully defined. Thus, we investigated the anti-tumor effect of xylodiol in human leukemia HL60 cell line. Xylodiol induced apoptosis and necrosis. HL60 cells treated with xylodiol showed biochemical changes characteristic of apoptosis, including caspases-8, -9 and -3 activation and loss of mitochondrial transmembrane potential (∆ Ψm). However, there was a condensation rather than swelling of mitochondria. Moreover, the formation of condensed mitochondria and the loss of ∆ Ψm occurred downstream of caspase activation. Cyclosporine A did not protect HL60 cells from the cytotoxic effects of xylodiol, suggesting that the loss of ∆ Ψm is a late event in xylodiol-induced apoptosis. Oxidative stress was involved in xylodiol-induced apoptosis. Thus, we conclude that activated caspases cleave cellular proteins resulting in mitochondrial damage leading to mitochondrial condensation, loss of ∆ Ψm and ROS release from the mitochondria. ROS can further induce and maintain a collapse of ∆ Ψm leading to cellular damage through oxidation of lipids and proteins resulting in apoptotic cell death.

Flavanones from aerial parts of Cordia globosa (Jacq.) Kunth, Boraginaceae / Flavanonas isoladas das partes aéreas de Cordia globosa (Jacq.) Kunth (Boraginaceae)

The phytochemical analysis of aerial parts of Cordia globosa, collected in the Municipality of Picuí, State of Paraíba, Brazil, resulted in the isolation and structural identification of narigenin-4',7-dimethyl ether (0.025 g) and eriodictyol (0.015 g). These compounds are the first flavanones aglycones isolated from the genus Cordia.

A análise fitoquímica das partes aéreas de Cordia globosa, coletadas no município de Picuí, PB, Brasil, resultou no isolamento e identificação estrutural da 7,4'-dimetilnarigenina (0,025 g) e eriodictiol (0,015 g). Estas duas flavanonas são as primeiras agliconas, desta classe, isoladas no gênero Cordia.

Effects of extract, fractions and 2,3-dihydromyricetin-3-O-α-L-rhamnoside from Pradosia huberi (Ducke) Ducke on rat isolated mesenteric arteries / Efeito do extrato, frações e da 2,3-diidromiricetina-3-O-α-L-raminosídeo obtidos da Pradosia huberi (Ducke) Ducke em artéria mesentérica isolada de rato

Pradosia huberi (Ducke) Ducke (Sapotaceae), an Amazonian species, is popularly known as "casca-doce" and used in the folk medicine for the treatment of gastritis. The ethanol extract of the bark contains mainly polyphenolic compounds, which are known to show a large number of activities, including cardioprotective and vasorelaxant effects. The aim of this study was to evaluate the pharmacological properties induced by P. huberi ethanol extract (PHEE) and fractions and 2-3-dihydromyricetin-3-O-α-L-rhamnoside derived from this extract, in isolated rat mesenteric arteries. PHEE was separated and the following fractions were obtained: CHCl3, CHCl3:AcOEt (1:1), AcOEt, AcOEt:MeOH (1:1) and MeOH. We isolated 2-3-dihydromyricetin-3-O-α-L-rhamnoside from the MeOH fraction, which was identified by¹H and 13C NMR spectra and compared with data in the literature. PHEE (1-100 µg/mL) induced concentration-dependent relaxations of 10 µM phenylephrine-induced tone (EC50=17,1±2,9 µg/mL; Emax=87.4±2.9 percent, n=8). The MeOH fraction also relaxed mesenteric rings (EC50=31±2.0 µg/mL; Emax=54±12.5 percent, n=6) but less effectively when compared to PHEE. Both effects were completely abolished after removal of the vascular endothelium. The AcOEt:MeOH (1:1) fraction and the isolated flavonoid were ineffective in eliciting vasorelaxation. The study demonstrates that PHEE and MeOH fraction of Pradosia huberi possess a vasorelaxant effect, which may be completely dependent upon endothelium. The isolated flavonoid is not responsible for this vasorelaxant effect.

Pradosia huberi (Ducke) Ducke (Sapotaceae), espécie Amazônica popularmente conhecida como "casca-doce" é utilizada na medicina tradicional no tratamento de gastrite. O extrato etanólico de suas cascas é rico em polifenóis que podem apresentar um grande número de atividades, incluindo efeito vasorelaxante e cardioprotetor. O objetivo deste estudo foi avaliar as propriedades farmacológicas do extrato etanólico (EPH), de frações e da 2,3-diidromiricetina-3-O-α-L-raminosídeo isolados de P. huberi, em artéria mesentérica isolada de rato. O EPH foi fracionado resultando nas seguintes frações: CHCl3, CHCl3:AcOEt (1:1), AcOEt, AcOEt:MeOH (1:1) e MeOH. Da fração MeOH foi isolada a 2,3-diidromiricetina-3-O-α-L-raminosídeo e identificada através de espectro de RMN de ¹H e 13C, além de comparações com os dados de literatura. EPH (1-100 µg/mL) promoveu relaxamento dependente de concentração no tônus vascular induzido por 10 µM de fenilefrina (CE50=17,1±2,9 µg/mL; Emax=87,4±2,9 por cento, n=8). A fração MeOH também relaxou os anéis mesentéricos (CE50=31±2,0µg/mL; Emax=54±12,5 por cento, n=6), porém com menor eficácia quando comparado ao efeito de EPH. Tanto o efeito de EPH com de MeOH foram completamente abolidos após a remoção do endotélio vascular. A fração AcOEt:MeOH (1:1) e o flavonoide isolado induziram vasorelaxamento. O estudo demonstrou que o EPH e a fração MeOH de Pradosia huberi apresentam propriedade vasorelaxante que pode ser completamente dependente da presença do endotélio. O flavonoide isolado não é o responsável por este efeito vasorelaxante.

Secondary metabolites isolated from Richardia brasiliensis Gomes (Rubiaceae) / Metabólitos secundários isolados de Richardia brasiliensis Gomes (Rubiaceae)

A família Rubiaceae compreende cerca de 637 gêneros e aproximadamente 10700 espécies, ocorrendo essencialmente nas regiões tropicais do Brasil. Richardia brasiliensis Gomes, popularmente conhecida por "poaia branca", é uma planta nativa da região sul do Brasil, utilizada na medicina popular como anti-emética e no tratamento de diabetes. Este trabalho reporta o isolamento e identificação estrutural de um flavonóide glicosilado, um triterpeno, uma cumarina e dois derivados de ácido benzóico, objetivando contribuir para quimiotaxonomia do gênero Richardia. Através deste estudo foi possível isolar e identificar os metabólitos isorametina-3-O-rutinosídeo, ácido oleanólico, a cumarina escopoletina e os ácidos p-hidroxi-benzóico e m-metoxi-p-hidroxi-benzóico, todos isolados pela primeira vez no gênero, exceto o último, apresentando, portanto, relevante importância quimiotaxonômica para o mesmo. As estruturas foram identificadas com o uso de técnicas espectroscópicas de IV, RMN ¹H e 13C uni e bidimensionais e comparação com dados da literatura.

The family Rubiaceae comprises around 637 genera and approximately 10,700 species, occurring essentially in tropical regions of Brazil. Richardia brasiliensis Gomes, known popularly as "poaia branca", is native to Brazil south region, used in folk medicine as anti-emetic and in the treatment of diabetes. This work reports the isolation and structural identification of a flavonoid glycoside, a triterpene, a coumarin and two benzoic acid derivatives, aiming at contributing to the chemotaxonomy of the genus Richardia, through a phytochemical study of Richardia brasiliensis. By means of this study the metabolites isorhamnetin-3-O-rutinoside, oleanolic acid, the coumarin scopoletin and p-hydroxy-benzoic and m-methoxy-p-hydroxy-benzoic acids were isolated and identified. All of them, but the latter, were isolated for the first time in the genus, thereby presenting relevant chemotaxonomic importance to it. The structures were identified using spectroscopic techniques such as IR, one and two-dimensional ¹H and 13C NMR besides comparison with literature data.

Composição química e modulação da resistência bacteriana a drogas do óleo essencial das folhas de Rollinia leptopetala R. E. Fries / Chemical composition and modulation of bacterial drug resistance of the essential oil from the leaves of Rollinia leptopetala R. E. Fries

O óleo essencial das folhasde Rollinia leptopetala foi obtido por hidrodestilação em aparelho de Clevenger e a sua composição química foi analisada através de CG-EM. Com essa técnica, foi possível identificar 22 constituintes em uma mistura complexa demonoterpenos (54,5 por cento) e sesquiterpenos (45,5 por cento). O principal componente encontradonas folhas foi o biciclogermacreno (22,47 por cento). O óleo essencial foi avaliado numa linhagem de Staphylococcus aureus portadora de bomba de efluxo responsável pela resistência norfloxacino. Embora o óleo essencial não tenha apresentado atividade antibacteriana relevante in vitro, ele apresentou atividade moduladora da resistência, ou seja, em combinação com o norfloxacino observou-se uma redução de 4x na concentração inibitória mínima do antibiótico, indicando inibição de bomba de efluxo.

The essential oil from the leaves of Rollinia leptopetala was obtained by hydrodistillation in Clevenger's apparatus and its chemical composition was analyzed by GC-MS. With this technique could be identified 22 constituents in a complex mixture of monoterpenes (54.5 percent) and sesquiterpenes (45.5 percent). The main component found in the leaves was the bicyclogermacrene (22.47 percent). The essential oil was assayed against a strain of Staphylococcus aureus possessing efflux mechanism of resistance to norfloxacin. Although the essential oil did not display relevant antibacterial activity in vitro, it modulated the activity of the norfloxacin, i.e. in combination with the antibiotic it was observed a fourfold reduction in the minimum inhibitory concentration for norfloxacin, indicating inhibition of efflux pump.

O Ácido (8)17,12E,14-labdatrieno-18-óico (labdano302), diterpeno tipo labdano isolado de Xylopia langsdorffiana St. Hil. & Tul. (Annonaceae) relaxa a traquéia isolada de cobaia / The (8)17,12E,14-labdatrien-18-oic acid (labdane302), labdane-type diterpene isolated from Xylopia langsdorffiana St. Hil. & Tul. (Annonaceae) relaxes the guinea-pig trachea

A espécie Xylopia langsdorffiana St. Hil.. & Tul. é popularmente conhecida como "pimenteira-da-terra" no Sudeste do Brasil. A partir do fracionamento do extrato etanólico, obtido das cascas do caule desta espécie, foi isolado um diterpeno tipo labdano, identificado como sendo o ácido 8(17),12E,14-labdatrieno-18-óico, e que neste trabalho é codificado como labdano302. O labdano302 relaxou o tônus basal dos anéis de traquéia isolada de cobaia com um valor de CE50 de 6,7 ± 0,5 x 10-8 M. O diterpeno labdano302 relaxou de maneira dependente de concentração os anéis pré-contraídos com carbacol (10-6 M), tanto na presença (CE50 = 1,4 ± 0,7 x 10-5 M) como na ausência de epitélio funcional (CE50 = 1,5 ± 0,3 x 10-5 M), bem como anéis pré-contraídos com 18 ou 60 mM de KCl, apresentando valores de CE50 de 2,3 ± 0,4 x 10(7) M e 1,8 ± 0,8 x 10-5 M, respectivamente. Este efeito relaxante, sobre as contrações induzidas por 18 mM de KCl, tanto foi significantemente mais potente quanto mais eficaz quando comparado ao efeito sobre as contrações induzidas por 60 mM de KCl. Assim, labdano302 mostra um efeito relaxante em traquéia isolada de cobaia, tanto em seu tônus basal como sob estímulo contrátil, aparentemente sem a participação dos fatores relaxantes derivados do epitélio, contudo com possível participação dos canais de K+.

Xylopia langsdorfiana St. Hil. & Tul. is popularly known as "pimenteira-da-terra" in Southeast of Brazil. The fractionation of the ethanol extract obtained from the stem-bark of this species yielded a labdane-type diterpene identified as 8(17),12E,14-labdatrien-18-oic acid, referred here as labdane302. In this study, we investigated the effect of labdane302 in guinea-pig trachea. labdane302 relaxed the basal tonus of trachea rings with EC50 value of 6.7 ± 0.5 x 10-8 M. The diterpene labdane302 relaxed the pre-contracted rings by carbachol 10-6 M both in the presence (EC50 = 1.4 ± 0.7 x 10-5 M) and absence of functional epithelium (EC50 = 1.5 ± 0.3 x 10-5 M), as well as pre-contracted by KCl 18 mM or 60 mM, presented EC50 values of 2.3 ± 0.4 x 10-7 M and 1.8 ± 0.8 x 10-5 M, respectively. This relaxant effect, upon contractions induced by KCl 18 mM, was more potent as well as more efficient than the one presented with KCl 60 mM pre-contracted rings. The labdane-type diterpene labdane302 shows the relaxant effect in isolated guinea-pig trachea, pre-contracted or upon basal tonus, apparently without participation of epithelium-derived relaxant factors, but apparently involving activation of K+ channels.