130 research outputs found
Hyperpigmentant activity of leaves and flowers extracts of Pyrostegia venusta on murine B16F10 melanoma
AbstractEthnopharmacological relevancePyrostegia venusta is a native Brazilian plant which has a variety of uses in traditional folk medicine including the treatment of vitiligo. However, its effectiveness on melanogenesis is not yet elucidated.Aim of the studyThis study aimed to investigate the melanogenic activity of hydroalcoholic extracts from the leaves and flowers of P. venusta on murine B16F10 melanoma cells.Materials and methodsDifferent concentrations of the hydroalcoholic extracts of flowers and leaves of P. venusta were evaluated in trials of spontaneous melanin content (4 days), and cell viability by the MTT assay in murine B16F10 cells, and in the mushroom tyrosinase activity in vitro.ResultsBoth extracts, leaves (0.1; 0.3; 1 and 3Όg/mL) and flowers (0.03 and 0.1Όg/mL) increased the melanin content in a concentration dependent manner after 4 days of incubation on melanoma cells. Leaves extract promoted enhancement of melanogenesis with maximum effect of 33.3±3% (3Όg/mL), and the flower extract increased in 23.4±3% (0.1Όg/mL). The cell viability test using MTT showed that in the same tested concentrations of both extracts no cell death was detected. Actually, either extract was not able to cause any change in the tyrosinase activity. HPLC analysis of P. venusta extracts found 0.09% and 1.08% of allantoin on leaves and flowers extracts, respectively.ConclusionsThe leaves and flowers extracts of P. venusta stimulates B16F10 melanogenesis at very low concentrations. These findings support the folk medicinal use of P. venusta on the treatment of hypopigmentation diseases, such as vitiligo
Triterpenes and the Antimycobacterial Activity of Duroia macrophylla
Duroia macrophylla popularly known as âcabeça-de-urubĂș,â âapuruĂ,â or âpuruĂ-grande-da-mataâ occurs in the Amazon Forest. Its leaves and branches were collected twice and extracted with dichloromethane and methanol. All extracts were subjected to phytochemical investigation and terpenes and flavonoids were found in all dichloromethane and methanol extracts, respectively. Methanol extracts from both branches (1st collection) and leaves (2nd collection) presented hydrolyzed tannins, yet alkaloids were only detected in the dichloromethane and methanol extracts from branches at the 2nd collection. Phenol compounds were found in both dichloromethane extracts' collections. The action of every extract was assayed against Mycobacterium tuberculosis (RMPr, H37Rv, and INHr strains), showing that the dichloromethane extract from leaves (1st collection) has the major biological activity, with a MIC of 6.25âÎŒg/mL for the INHr strain, 25.0âÎŒg/mL for the RMPr strain, and â€6.25âÎŒg/mL for the H37Rv strain. The chromatographic fractioning of the dichloromethane extract from leaves (1st collection) yielded the isolation of two triterpenes: oleanolic and ursolic acids, which were identified by NMR analysis and reported for the first time in the Duroia genus
Caracterização por ressonùncia magnética nuclear de sucos de maçã obtidos por preparaçÔes enzimåticas
In this work, ÂčH Nuclear Magnetic Resonance (ÂčH NMR) was employed to evaluate changes in apple juice in response to the addition of PanzymÂź Yieldmash and UltrazymÂź AFP-L enzymatic complexes and compare it with premium apple juice. The juice was processed at different temperatures and concentrations of enzymatic complexes. The differences in the results were attributed mainly to the enzyme concentrations, since temperature did not cause any variation. A quantitative analysis indicated that the concentration of fructose increased while the concentrations of sucrose and glucose decreased in response to increasing concentrations of the enzymatic complexes
Search for alkaloids on callus culture of Passiflora alata
Preliminary work on Passiflora alata leaves failed to detect harmane alkaloids using LC. The aim of this work was to investigate the production of harmane alkaloids through the cell culture of P. alata, inducing its precursor (L-tryptophan). The leaf explants presented satisfactory results after disinfection, and the callus formation was initiated in MS media with adequate quantities of phytohormones. Sixty days after inoculation, calli were inoculated in the optimized semi-solid MS media, with and without the addition of L-tryptophan (50, 100, 200 mg/L) and kept in standard conditions for 90 days. Calli were collected on days 6, 16, 26, 36, and 90, followed by acid-base extraction, and analysed by LC. The results showed an absence of harmane, harmin, harmol, harmalol, and harmaline. With L-tryptophan feeding, two peaks were detected, collected and analysed through positive mode electrospray [ESI(+)-MS] and sequential analysis in tandem ESI(+)-MS/MS. The spectra obtained were very similar, with a repetition of the more intense ions, and consecutive loss of 68 Da units, attributed to the heterocycle pyrazole. It appeared that this transformation was not related to any enzymatic pathway previously described for the plant from L-tryptophan, and the biosynthesis of β-carboline alkaloids in callus culture of P. alata were not observed in this work.As folhas de varias espĂ©cies de Passiflora sĂŁo utilizadas como ansioliticas e sedativas. Passiflora alata Curtis, Passifloraceae consta em trĂȘs ediçÔes da farmacopĂ©ia brasileira, porem nĂŁo hĂĄ muitos estudos sobre sua composição quĂmica. No passado, enfatizava-se a ação conjunta de alcalĂłides e flavonĂłides. Em trabalho anterior, nĂŁo foi detectada a presença de alcalĂłides harmanicos atravĂ©s de CLAE. Assim, decidiu-se investigar a produção dos mesmos atravĂ©s de cultivo celular, introduzindo seu precursor metabĂłlico L-triptofano. Os explantes foliares apresentaram resultados satisfatorios para germinação apos assepsia, e a formação de calo foi iniciada em meio MS com quantidades adequadas de fitohormonios, previamente determinadas. Sessenta dias apĂłs a inoculação os calos foram repicados para meio semi-solido com e sem L-triptofano (50, 100, 200 mg/L), mantidos por 90 dias em condiçÔes padrĂŁo. Amostras foram coletadas com 6, 16, 26, 36, e 90 dias, realizada extração acido-base e o extrato analisado por CLAE. Os resultados mostraram a ausĂȘncia de harmana, harmina, harmol, harmalol e harmalina. Dois picos presentes nas amostras com L-triptofano foram coletados e analisados atravĂ©s de espectrometria de massas, electrospray modo positiva [ESI(+)-MS] e analise em tandem ESI(+)-MS/MS. Os espectros correspondentes foram similares, mostrando a perda consecutiva de 68 Da, atribuĂdos ao pirazol. Este fato aponta para uma transformação nĂŁo enzimĂĄtica, nĂŁo relacionada a uma biossintese previamente descrita para alcalĂłides β-carbolĂnicos.90191
A new polyacetylene from Vernonia scorpioides (Lam.) Pers. (Asteraceae) and its in vitro antitumoral activity
The dichloromethane fraction obtained from hydroalcoholic crude extract of leaves and flowers of Vernonia scorpioides (Asteraceae) was investigated, resulting in the isolation and structure elucidation of a new polyacetylene namely 5-octa-2,4,6-triynyl-furan-2(5H)-one. The structure of the isolated compound was determined based on IR, NMR (1D and 2D) and MS spectrometric data. The antitumor potential, including cytotoxicity to tumor cells and genotoxicity, was investigated. The results suggest that apoptotic cell death may have occurred, at least in part, via a caspase-dependent mechanism.A fração diclorometano obtida pelo particionamento do extrato hidroalcoĂłlico obtido das folhas e flores de Vernonia scorpioides (Asteraceae) resultou no isolamento e caracterização de um novo poliacetileno, 5-octa-2,4,6-triinil-furan-2(5H)-ona. A determinação estrutural foi baseada em dados de espectrometria de RessonĂąncia MagnĂ©tica Nuclear mono e bidimensionais, de Massas e de Infravermelho. Foi investigado o potencial antitumoral e genotĂłxico do novo poliacetileno e os resultados encontrados sugerem genotoxicidade e citotoxicidade, onde a morte celular ocorreu via apoptose, envolvendo um mecanismo dependente de caspase.13271333Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de NĂvel Superior (CAPES
Chemical study of Sinningia allagophylla guided by antiproliferative activity assays
Activity guided fractionation of Sinningia allagophylla (Mart.) Wiehler ethanolic extract yielded a new benzochromene 8-methoxylapachenol, besides seven known compounds: lapachenol, sitosteryl oleate, sitosteryl linoleate, stigmasteryl oleate, stigmasteryl linoleate, dunniol and tectoquinone. Extract, fractions, and compounds lapachenol, 8-methoxylapachenol, and dunniol were tested in vitro against human cancer cell lines U251 (glioma, CNS), MCF-7 (breast), NCI-ADR/RES (drug-resistant ovarian), 786-0 (kidney), NCI-H460 (lung, no small cells), PC-3 (prostate), OVCAR-3 (ovarian), HT-29 (colon), K562 (leukemia) and against VERO, a normal cell line. The most active compound was dunniol, which inhibited the growth of U251, MCF-7, NCI-ADR/RES, OVCAR-3 and K562 cell lines.974977Fundação de Amparo Ă Pesquisa do Estado de SĂŁo Paulo (FAPESP)Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de NĂvel Superior (CAPES
Anti-tuberculosis activity of oleanolic and ursolic acid isolated from the dichloromethane extract of leaves from Duroia macrophylla
Chemical composition, larvicidal and cytotoxic activity of Annona salzmannii (Annonaceae) seed oil
The seed oil of Annona salzmannii A. DC. was analyzed by GC-MS and 1 H qNMR, revealing a mixture of unsaturated (80.5%) and saturated (18.7%) fatty acids. Linoleic (45.3%) and oleic (33.5%) acid were the major unsaturated fatty acids identified, while palmitic acid (14.3%) was the major saturated fatty acid. The larvicidal effects of A. salzmannii seed oil were evaluated against third-instar larvae of Aedes aegypti (Linn.). The oil exhibited moderate larvicidal activity, with aLC50 of 569.77 ppm (95% CI = 408.11 to 825.88 ppm). However, when the cytotoxic effects of the oil were evaluated, no expressive antiproliferative effects were observed in tumor cell lines B16-F10 (mouse melanoma), HepG2 (human hepatocellular carcinoma), K562 (human chronic myelocytic leukemia), HL-60 (human promyelocytic leukemia), and non-tumor cell line PBMC (peripheral blood mononuclear cells), with IC50 values > 50 Όg·mL-1. This is the first study to evaluate the chemical composition, larvicidal and cytotoxic activity of A. salzmannii seed oil
Structural, vibrational, and electronic properties of the glucoalkaloid strictosidine: A combined experimental and theoretical study
A detailed structural analysis and spectral behavior of the glucoalkaloid strictosidine, a precursor of all monoterpene indole alkaloids, are discussed. The experimental NMR, FTIR, and UV results were compared to the theoretical DFT spectra calculated by Becke using the three-parameter Lee-Yang-Parr (B3LYP) function with 6-31G(d) and 6-311++G(2d,p) basis sets. The theoretical geometry optimization data were compared with the X-ray data for precursors and similar structures in the associated literature. The similarity between the theoretical and experimental coupling constants values made it possible to affirm the values of dihedral angles and their configuration, reinforcing findings from previous stereochemical studies. Theoretical UV analysis agreed well with the measured experimental data, with bands assigned. Calculated HOMO/LUMO gaps show low excitation energy for strictosidine, justifying its stability and reaction kinetics. The molecular electrostatic potential map shows opposite potentials regions that form hydrogen bonds that stabilize the dimeric form, which were confirmed by excellent agreement of the dimeric form theoretical wavenumbers with the experimental IR spectrum. ESI-MS/MS data revealed patterns for the fragmentation of the protonated strictosidine molecule outlined by an NBO study. © 2016 Renyer Alves Costa et al
fac-/mer-[Ru'Cl IND. 3'(NO)(P-N)] (P-N = [o-(N,N-dimethylamino)phenyl]diphenylphosphine): synthesis, characterization and DFT calculations
Complex fac-[RuCl3(NO)(PâN)] (1) was synthesized from the reaction of [RuCl3(H2O)2(NO)] and the PâN ligand, o-[(N,N-dimethylamino)phenyl]diphenylphosphine) in refluxing methanol solution, while complex mer,trans-[RuCl3(NO)(PâN)] (2) was obtained by photochemical isomerization of (1) in dichloromethane solution. The third possible isomer mer,cis-[RuCl3(NO)(PâN)] (3) was never observed in direct synthesis as well as in photo- or thermal-isomerization reactions. When refluxing a methanol solution of complex (2) a thermally induced isomerization occurs and complex (1) is regenerated.\ud
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The complexes were characterized by NMR (31P{1H}, 15N{1H} and 1H), cyclic voltammetry, FTIR, UVâVis, elemental analysis and X-ray diffraction structure determination. The 31P{1H} NMR revealed the presence of singlet at 35.6 for (1) and 28.3 ppm for (2). The 1H NMR spectrum for (1) presented two singlets for the methyl hydrogens at 3.81 and 3.13 ppm, while for (2) was observed only one singlet at 3.29 ppm. FTIR RuâNO stretching in KBr pellets or CH2Cl2 solution presented 1866 and 1872 cmâ1 for (1) and 1841 and 1860 cmâ1 for (2). Electrochemical analysis revealed a irreversible reduction attributed to RuIIâNO+ â RuIIâNO0 at â0.81 V and â0.62 V, for (1) and (2), respectively; the process RuII â RuIII, as expected, is only observed around 2.0 V, for both complexes.\ud
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Studies were conducted using 15NO and both complexes were isolated with 15N-enriched NO. Upon irradiation, the complex fac-[RuCl3(NO)(PâN)] (1) does not exchange 14NO by 15NO, while complex mer,trans-[RuCl3(NO)(PâN)] (2) does. Complex mer,trans-[RuCl3(15NO)(PâN)] (2âČ) was obtained by direct reaction of mer,trans-[RuCl3(NO)(PâN)] (2) with 15NO and the complex fac-[RuCl3(15NO)(PâN)] (1âČ) was obtained by thermal-isomerization of mer,trans-[RuCl3(15NO)(PâN)] (2âČ).\ud
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DFT calculation on isomer energies, electronic spectra and electronic configuration were done. For complex (1) the HOMO orbital is essentially Ru (46.6%) and Cl (42.5%), for (2) Ru (57.4%) and Cl (39.0%) while LUMO orbital for (1) is based on NO (52.9%) and is less extent on Ru (38.4%), for (2) NO (58.2%) and Ru (31.5%).CNPqCAPESFINE
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