Resumo A atividade antioxidante do mel de Tetragonisca angustula (TAH) e seu extrato etanólico (TAEE) foram investigados. Os níveis totais de fenólicos (TPC) e flavonóides (TFC) também foram avaliados. Os resultados para TPC foram 19,91 ± 0,38 e 29,37 ± 1,82 mg GAE g-1 e para TFC 0,20 ± 0,02 e 0,14 ± 0,01 mg QE g-1 de TAH e TAEE, respectivamente. As atividades antioxidantes foram 73,29 ± 0,49% e 93,36 ± 0,27% no ensaio DPPH● e 71,73 ± 4,07% e 97,86 ± 0,35% no ABTS●+ para TAH e TAEE, respectivamente. A atividade redutora total foi determinada pelo método de poder redutor (PR) e íon ferrico (Fe III) e os resultados variaram em PR de 151,7 ± 25,7 e 230,7 ± 25,2 mg GAE L-1, para TAH e TAEE respectivamente e para (Fe III) em EC50 0,284 em TAEE e 0,687 em TAH. A análise química por HPLC-DAD do extrato etanólico (TAEE) revelou a presença de ácido ferúlico como componente majoritário no extrato. A análise de RMN 1H confirmou esta estrutura e mostrou a presença de glicose, ácido cítrico, ácido succínico, prolina e derivados de hidrocarbonetos no TAEE. Além disso, a origem botânica também foi investigada e apresentou característica multifloral, tendo encontrado 19 tipos polínicos com predomínio botânico da família Anacardiaceae, sendo o pólen Tapirira predominante (42,6%) e o Schinus secundário (25,7%). Os resultados mostraram que o mel de T. angustula é uma interessante fonte de compostos fenólicos antioxidantes devido à sua origem floral e pode atuar como protetor da saúde humana quando consumido.

Abstract The antioxidant activity of Tetragonisca angustula honey (TAH) and its ethanolic extract (TAEE) were investigated. The total levels of phenolic (TPC) and flavonoids (TFC) were also evaluated. The results for TPC were 19.91 ± 0.38 and 29.37 ± 1.82 mg GAE g-1 and for TFC 0.20 ± 0.02 and 0.14 ± 0.01 mg QE g-1 of TAH and TAEE, respectively. Antioxidant activities were 73.29 ± 0.49% and 93.36 ± 0.27% in the DPPH● assay and 71.73 ± 4.07% and 97.86 ± 0.35% in ABTS●+ for TAH and TAEE, respectively. The total reducing activity was determined by the method of reducing power (PR) and iron ion (Fe III) and the results varied in PR from 151.7 ± 25.7 and 230.7 ± 25.2 mg GAE L-1, for TAH and TAEE respectively and for (Fe III) in EC50 0.284 in TAEE and 0.687 in TAH. Chemical analysis by HPLC-DAD of the ethanolic extract (TAEE) revealed the presence of ferulic acid as majority phenolic component in the extract. The 1H NMR analysis confirmed this structure and showed the also presence of glucose, citric acid, succinic acid, proline and hydrocarbon derivatives. In addition, the botanical origin was also investigated and showed a multifloral characteristic, having found 19 pollen types with a botanical predominance of the Anacardiaceae family, with Tapirira pollen occurring as predominant (42.6%) and Schinus as secondary (25.7%). The results showed that T. angustula honey is an interesting source of antioxidant phenolic compounds due to its floral origin and can act as a protector of human health when consumed.

The phytochemical reinvestigation from the heartwood of the extracts of Cordia glazioviana led to the isolation of four still undescribed hydroquinones derivatives designated as cordiaquinol D (1), cordiaquinol E (2), (10R)-10,11-dihydrofuran-1,4-dihydroxy-globiferin (3) and 2-[(1’E,6’E)-3’,8’- dihydroxy-3’,7’-dimethylocta-1’,6’-dienyl]-benzene-1,4-diol (4), along with the naphthoquinone 6-[(2’R)-2’-hydroxy-3’,6’-dihydro-2H-pyran-5’-yl]-2-methoxy-7-methylnaphthalene-1,4-dione (5). Additionally, six previously known compounds were also isolated: rel-1,4-dihydroxy-8(,11(;9(,11(-diepoxy-2-methoxy-8a(-methyl-5,6,7,8,8a,9,10,10a-octahydro-10-antracenone (6), didehydroconicol (7), 1(,6(-dihydroxy-7-epi-eudesm-3-ene (8), 1(,6(-dihydroxy-7-epi-eudesm-4(15)-ene (9), 10,11-dihydroxybisabolol (10), and hamanasal-A (11). The structures of the new compounds were assigned by high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) analyses. The relative stereochemistry of 3, 4, and 5 was improved by quantum mechanical calculations. Eight, out of the eleven isolated compounds (2-9), were tested through cellular viability and lipopolysaccharide (LPS)-induced inflammation assays against RAW 264.7 macrophage-like cells. Compounds 3-5 exhibited a stronger effect on LPS-induced NO production (half-maximal inhibitory concentration (IC50) 50.34, 105.83, and 66.73 µM, respectively).

Abstract Phytochemical studies of Cespedesia spathulata (Ochnaceae) leaves using 1H, 13C NMR, and GC-MS have led to the isolation of some metabolites identified for the first time in these species such as cathechin, epicatechin, vitexin, orientin, 6’’-O-acetyl-vitexin, sitosterol, stigmasterol, phytol, 4,5-dihydrovomifoliol and a mixture of aliphatic methyl esters, together with ochnaflavone, which was previously isolated from this plant. The modulating activity of some fractions and compounds from Cespedesia spathulata towards tyrosinase enzyme was assayed by spectroscopic and theoretical means/experiments. The dichloromethane fraction (133 μg mL-1) and ochnaflavone (333 μM) inhibited tyrosinase activity by 20 % and 2.0 %, respectively, whereas the ethyl acetate fraction (666 μg mL-1) and ±catechins (catechin and epicatechin - 800 μM) activated it by 104 % and 384 %, respectively. Quantum chemical calculations suggested that catechin and epicatechin are better activators than L-DOPA by interacting with Cu (II) ions. Molecular docking results suggested that hydrogen bonding and hydrophobic interactions are the main binding forces between each tyrosinase activator and the amino acid residues inside the active protein binding pocket.

Abstract The essential oils obtained by hydrodistillation from fresh leaves of Vitex agnus-castus and Ocimum campechianum, and from fresh inflorescences of Ocimum carnosum were analysed by GC-FID and GC-MS. The major components of V. agnus-castus essential oil were identified as 1,8-cineole (47.9%), terpinyl α-acetate (11.6%), sabinene (11.2%) and caryophyllene oxide (9.7%), while in the O. campechianum essential oil were eugenol (72.1%), β-elemene (6.8%), (E)-caryophyllene (6.4%) and bicyclogermacrene (5.2%). Linalool (79.0%), α-epi-cadinol (5.4%), terpinen-4-ol (3.2%) and 1,8-cineole (2.8%) were the major constituents in the O. carnosum essential oil. The essential oils were subsequently evaluated for their larvicidal and cytotoxic activities. Larval bioassay against Aedes aegypti of V. agnus-castus, O. campechianum and O. carnosum essential oils showed LC50 values of 97.55 ± 0.35, 81.45 ± 0.35 and 109.49 ± 0.35 μg/mL, respectively. The in vitro cytotoxic activities of the essential oils has been evaluated on breast adenocarcinoma (MCF-7), lung carcinoma (NCI-H292), pro-myelocytic leukemia (HL-60), and cervical adenocarcinoma (HEP-2) human cell lines, and pro-myelocytic leukemia cells lines (HL-60) were found to be the most sensitive to all the essential oils tested than the others. This is the first report on larvicidal and cytotoxic activities of these essential oils.

Abstract The chemical study of roots from Azadirachta indica A. Juss., Meliaceae, led to the isolation of two new terpenoids, limonoid morenolide and diterpene 17-hydroxy-sandaracopimar-8,15-dien-11-one, in addition to the four well-known limonoids nimbinene, nimbinal, nimbandiol and salannin, and three diterpenoids nimbidiol, ferruginol, and 6,7-dehydroferruginol. Their structural elucidations were based on one and bidimensional Nuclear Magnetic Resonance and Electrospray ionization mass spectrometry spectra data which was compared to the data found in literature. The anti-inflammatory, cytotoxic and antimycobacterial activities of the identified terpenoids were evaluated.

Resumo Concretos de alta resistência (CAR) correspondem a uma resistência à compressão característica compreendida entre 55 e 90 MPa. Com a possibilidade crescente da utilização de CAR, faz-se necessária a realização de estudos que abordem os tratamentos normativos usuais acerca do dimensionamento de elementos por ele constituídos, especificamente, à ação de força cortante. Portanto, são apresentadas os principais aspectos da NBR, Model Code 1990 e 2010, Norma portuguesa e alemã acerca dos dimensionamento à cortante. Das simulações numéricas, acrescidas das contribuições experimentais de Cladera e Marí, constata-se que o procedimento de cálculo da NBR produz áreas de estribos inferiores às previstas pelos códigos internacionais; estes, com exceção do LoA III, não adotam a contribuição do concreto, apesar de esta ser verificada experimentalmente, levando a resultados muito conservadores.

Abstract High strength concretes (HSC) correspond to a characteristic compression strength between 55 e 90 MPa. With the growing use of HSC, studies about the regular design standards of elements made of it, specifically standards about design on shear, become necessary. Hence, the main aspects of the NBR, Model Code 1990 e 2010, Portuguese Standard and German Standard related to the design on shear are presented. From the numerical simulations, with the addition of Cladera and Marí’s experimental contributions, it is confirmed that the Brazilian design standard procedure produces lower transverse reinforcement areas in comparison to the ones predicted by the international codes; these, excepted by LoA III, do not consider the concrete contribution, in spite of being experimentally verified, leading to very conservative results.

A phytochemical investigation from aerial parts of Casearia arborea (Rich.) Urb. (Salicaceae) led to isolation and identification of: sitosterol, 4-en-stigmast-3-one, 13-hydroxy-trans-ent-cleroda-3,14-diene,3-hydroxy-2-oxo-trans-ent-cleroda-3,14-diene (kolavelone), a mixture of 13-hydroxy-trans-ent-cleroda-3,14-diene and an ester ethyl hexadecanoate, kaempferol-3-O-a-L-arabinofuranoside and 4',5,7-trihydroxy-3',5'-dimethoxyflavone (tricin). The compounds have been described for the first time in this species. Five trihydroxy-flavone-hexoside derivatives have been identified by LC-ESI-HR-MS. The antimicrobial activity of kolavelone was evaluated against strains of Staphylococcus, Bacillus, Pseudomonas, Shigella and Candida spores, and its minimum inhibitory concentration (MIC) was determined. The results showed the antimicrobial activity of kolavelone against several bacteria and Candida tropicalis indicating its potential use as antimicrobial agent.

Binding between bovine serum albumin (BSA) and a plumeran indole alkaloid (PIA) isolated from the stem bark of Aspidosperma cylindrocarpon (Apocynaceae) was studied by spectroscopic techniques (UV-Vis absorption, circular dichroism, steady state and time-resolved fluorescence), combined with molecular docking. Steady state and time resolved fluorescence data revealed that PIA can quench the BSA fluorescence via a static mechanism: energy transfer from BSA to PIA occurs with high probability. The binding is strong (Kb ca. 105-106 L mol-1), spontaneous (ΔG° ca. -35.7 kJ mol-1 at 310 K) and entropy-driven (ΔS° = 0.146 kJ mol-1 K-1). There is just one main binding site (n ca. 1) for the BSA:PIA interaction and the α-helix content of the albumin does not suffer significant perturbation upon PIA binding. Molecular docking results suggest site I as the main binding site to PIA, which is able to interact with the Trp-212, Arg-217, Val-342 and Pro-446 residues.

Four new alkaloids, Brazoides A-D, together with three known compounds squalene, β-sitosterol and lupeol, were isolated from leaves of Justicia gendarussa. These structures were established by spectrometric techniques, mainly high-resolution electrospray ionization mass spectrometry (HRESIMS) and 1D and 2D nuclear magnetic resonance (NMR), including comparative analysis with literature values. Structural determination of the compounds, Brazoides A-D, was strengthened by molecular modeling and density functional theory (DFT) calculations to predict the NMR data and compare with the experimental NMR values of these natural products. The new compounds were tested against three human cancer cell lines (glioblastoma, prostate and colon), but none exhibited activity.

ABSTRACT This study aims to identify special metabolites in polar extracts from Urochloa humidicola (synonym Brachiaria humidicola) that have allelopathic effects and induce secondary photosensitization in ruminants. The compounds were isolated and identified via chromatographic and spectroscopic techniques. The compounds 4-hydroxy-3-methoxy-benzoic acid, trans-4-hydroxycinnamic acid, and p-hydroxy-benzoic acid; the flavonols isorhamnetin-3-O-β-d-glucopyranoside and methyl quercetin-3-O-β-d-glucuronate; and kaempferitrin, quercetin-3-O-α-l-rhamnopyranoside, and tricin were identified in the extract from the leaves of Urochloa humidicola. Two furostanic saponins, namely, dioscin and 3-O-α-l-rhamnopyranosyl-(1-4)-[α-l-rhamnopyranosyl-(1-2)]-β-d-glucopyranosyl-penogenin, as well as catechin-7-O-β-d-glucopyranoside were identified in the methanolic extract obtained from the roots of this plant. This species features a range of metabolites that may be toxic for animals if used in food and may interfere with the growth medium, thereby inhibiting the development of other species.

ABSTRACT A new lactone, 7-epi-griffonilide (1), and six known compounds, 2, 3a - 3c, 4a and 4b, were isolated from the leaves of Bauhinia pentandra (Fabaceae). The structures elucidation of 1 and 2 were based on detailed 2D NMR techniques and spectral comparison with related compounds, leading to complete assignment of the 1H and 13C NMR spectra.

Four new epimeric spirostanol and furostanol-type steroidal saponins, (25R,S)-5α-spirostan-2α,3β-diol 3-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranosyl-(1→4)-β-D-galactopyranoside, (25R,S)-5α-spirostan-2α,3β-diol 3-O-β-D-glucopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1→4)-β-D-galactopyranoside, 26-O-β-D-glucopyranosyl-(25R,S)-5α-furost-20-ene,2α,3β-diol 3-O-β-D-galactopyranoside and 26-O-β-D-glucopyranosyl-(25R,S)-5α-furost-20-ene,2α,3β-diol 3-O-β-D-galactopyranosyl-(1→4)-β-D-galactopyranoside, in addition to the known (25R,S)-5α-spirostan-2α,3β-diol 3-O-β-D-galactopyranoside, were isolated from Cestrum laevigatum. Compounds were submitted to cytotoxic activity assays using colorectal adenocarcinoma (HCT-116), human promyelocytic leukemia (HL-60), ovarian carcinoma (OVCAR-8), glioma (SF-295) human cancer cell lines, and the antimicrobial activity was evaluated against Candida parapsilosis, C. albicans, C. krusei, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis.

ABSTRACT The larvicidal activity of the methanol extract, fractions and compounds 2-hydroxy-4-methoxy-6-propyl-methyl benzoate and (+)-usnic acid identified from the lichen Ramalina usnea (L.) R. Howe, Ramalinaceae, was tested against the third instar larvae of the Aedes aegypti mosquito. The methanol extract and three fractions showed activity, killing 100% and 96.6% of the larvae at a concentration of 150 µg/ml at 24 h. The isolated compounds, 2-hydroxy-4-methoxy-6-propyl-methyl benzoate and the (+)-usnic acid showed larvicidal activity, presenting LC50 values of 4.85 and 4.48 µg/ml, respectively. This is the first study of its kind reporting the larvicidal activity against the A. aegypti mosquito with compound (1).

Two new meroterpenoid hydroquinones,rel-(4bE,6Z,8E,9aS,10S)-1,4-dihydroxy-9a,10-dihydro-10,12-epoxy-5-methylbenzo[a]azulen-12-one andrel-(4bZ,6Z,8E,9aS,10S)-1-hydroxy-9a,10-dihydro-4,11:10,12-diepoxy-benzo[a]azulen-11,12-dione, along with the known peptide derivative (S)-N-benzoylphenylalanine-(S)-2-benzamide-3-phenylpropyl ester, were isolated from the roots of Cordia globosa. Their structures were determined by 1D and 2D nuclear magnetic resonance (NMR) spectrometry, Fourier transform infrared (FTIR) spectroscopy and high resolution atmospheric pressure chemical ionization mass spectrometry (HRAPCIMS) data analysis. The new compounds were tested against three human cancer cell lines (colon adenocarcinoma, ovarian carcinoma and glioblastoma), but none of them exhibited any activity.

One new alkaloid, 2α-10bα-dihydroxy-9-O-demethylhomolycorine, in addition to seven others known alkaloids, and 5-(hydroxymethyl)furfural, piscidic acid and eucomic acid, were isolated from the bulbs of Hippeastrum solandriflorum. The structures of all compounds were determined using nuclear magnetic resonance (NMR) spectroscopic techniques: 1H NMR and 13C NMR, heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond correlation (HMBC), nuclear Overhauser effect spectroscopy (NOESY), and also the high-resolution electrospray ionization mass spectrometry (EI-HRMS). The cytotoxic activity of all alkaloids was evaluated against three human cancer cell lines (HCT-116, HL-60, OVCAR8 and SF-295) showing IC50 values ranging from 0.01 to 35.7 µM.