Vegetable oils are alternatives to producing renewable monomers since they are biomass. It is possible to react them with anhydrides by heating to provide monomers with high reactivity. However, after the reaction of grape seed oil with itaconic anhydride, it was observed the occurrence of parallel reactions that had not been observed when the same oil was reacted with maleic anhydride. Some articles in the literature have reported that temperature and bases can isomerize itaconic anhydride into citraconic anhydride, which is more stable at room temperature. However, they have not focused on completely understanding how this phenomenon occurred nor studied it in processes that involve microwave irradiation. Therefore, this paper presents a complete characterization and investigation about the thermal behavior of itaconic anhydride and how it can affect the monomer synthesis performed under heating. biomass reactivity However irradiation Therefore

The aim of this paper is to replace toxic coinitiators (tertiary amines) by non-toxic compounds such as glycerol and inositol (polyalcohol) in dimethacrylate resins. For this purpose, mid infrared spectroscopy (MIR) was used to calculate the monomers' degree of conversion (%DC); as well as simultaneous Thermogravimetric Analysis – Differential Thermal Analysis (TGA-DTA) and Differential Scanning Calorimetry (DSC) were conducted to evaluate thermal stability, degradation steps, and thermal events. The use of different initiator systems did not modify the thermal events or the thermal stability of each of the dimethacrylate resins. Results show a substitution of system 2 (toxicity) by system 3 (low toxicity), which had a good conversion velocity and total conversion in some monomers, is plausible.

ABSTRACT Operculina macrocarpa (L.) Urb., Convolvulaceae, is used by the population as a laxative. In this work we described the isolation of the three phenolic acids present in the hydroethanolic extract of the O. macrocarpa roots. The quantification of the caffeic, chlorogenic acids and of the new caffeic dimer in the hydroethanolic and infusion extracts was performed by high-performance liquid chromatography coupled photodiode array detector. These analyses showed the higher content of the chlorogenic, caffeic and the new 3,4'-dehydrodicaffeic acid in hydroethanolic and hydroethanolic extracts without resin in which infusion. The acid found in greater quantity is caffeic acid followed by the 3,4'-dehydrodicaffeic acid. The laxative activity was evaluated by different experimental models of intestinal transit with the hydroethanolic and infusion extracts, and the resin fraction, caffeic, chlorogenic and ferulic acids. The results showed all extracts and compounds tested had significant activity in the experimental model tested. These results obtained are essential for the future development of a pharmaceutical product with safety and efficacy.

A goiaba (Psidium guajava L.) é uma planta bastante utilizada na medicina popular. Recentemente alguns trabalhos tem alertado acerca da toxicidade de substâncias presentes em plantas medicinais, o que pode trazer riscos à saúde humana. Neste sentido, o presente trabalho objetivou investigar a ação fitotóxica, citotóxica e genotóxica de três variedades de goiaba - Paluma, Pedro Sato e Roxa - no sistema teste vegetal Lactuca sativa L. Assim, foram realizadas avaliações macro- e microscópicas para cinco concentrações de infusões (2,5, 5,0, 10,0, 20,0 e 40,0 g.L-1) preparadas a partir de cada variedade. A água destilada foi usada como controle negativo. As análises cromatográficas e espectroscópicas por HPLC-PAD indicaram que a composição química da infusão da Roxa é diferente das infusões das variedades Paluma e Pedro Sato. Foi observado que a germinação das sementes e o crescimento da raiz em L. sativa expostas às infusões diminuem com o aumento da concentração da infusão, independentemente da cultivar testada. Para o índice mitótico, diferenças estatísticas não foram observadas. Por outro lado, foi verificado um aumento significativo na frequência de alterações do ciclo celular, especialmente para as maiores concentrações testadas. O efeito citogenotóxico foi significativo. Portanto, a goiaba não deve ser utilizada indiscriminadamente na medicina popular.

Guava (Psidium guajava L.) is a plant often employed in popular medicine. Recently several studies have alerted about the toxicity of substances present in medicinal plants, which can pose risks to the human health. In this sense, the present work aimed to investigate the phytotoxic, cytotoxic and genotoxic action of three guava varieties - Paluma, Pedro Sato and Roxa ("purple") - on the plant test system Lactuca sativa L. Thus, macro- and microscopic evaluations were carried out for five infusion concentrations (2.5, 5.0, 10.0, 20.0 and 40.0 g.L-1) prepared from each variety. Distilled water was used as negative control. Chromatographic and spectroscopic analysis by HPLC-PAD indicated that the chemical composition of the infusion of Roxa is different than that of the infusions of the varieties Paluma and Pedro Sato. It was observed that seed germination and root growth in L. sativa exposed to infusions decreased with increasing infusion concentration, regardless of the tested cultivar. For the mitotic index, no statistical differences were observed. On the other hand, a significant increase in the frequency of cell cycle alterations was verified, especially for the highest concentrations tested. The cytogenotoxic effect was significant. Therefore, guava should not be used indiscriminately in popular medicine.

This article describes the isolation and identification of flavonoids in the hydroethanolic extract of the aerial parts from Tonina fluviatilis and evaluation of their antiradical activity. A method based on HPLC-DAD was developed and validated for detecting and quantifying flavonoids in hydroethanolic extracts. The flavonoids identified and quantified in the extract were 6,7-dimethoxyquercetin-3-O-β-D-glucopyranoside (1), 6-hydroxy-7-methoxyquercetin-3-O-β-D-glucopyranoside (2), and 6-methoxyquercetin-3-O-β-D-glucopyranoside (3). The developed method presented good validation parameters, showing that the results obtained are consistent and can be used in ensuring the quantification of these constituents in the extracts. Compounds 2 and 3 showed strong antiradical activity when compared with the positive controls (quercetin and gallic acid).

An analytical method based on high-performance liquid chromatography with electrochemical detection has been developed and applied to the determination of Solvent blue 14 (SA-14) and Solvent red 24 (SV-24) in fuel samples. The dyes were better separated on C18 column, using a mobile phase composed of acetonitrile and ammonium acetate (90:10, v/v). Detection was carried out at an oxidation potential of +0.85V. The detector response was linear at concentration range of 7.50×10-8 - 1.50×10-6 mol L-1 (r = 0.997) for SA-14 and SV-24, respectively. The method was used to quantify these dyes in fuels samples with satisfactory accuracy and precision.

Phytochemical investigation of ethanolic leaves extracts of T. fagifolia led to the isolation of (+)-catechin, sitosterol-3-O-β-D-glucopyranoside, α- and β-tocopherol, a mixture of lupeol, α- and β-amyrin, sitosterol and a mixture of glicosid flavonoids (CP-13). The structures of these compounds were identified by ¹H and 13C NMR spectral analysis and comparison with literature data. Absolute configuration of the catechin was determinate by circular dichroism. Antioxidant activity (EC50), evaluated by 2,2-diphenyl-1-picrylhidrazyl (DPPH) assay system, decreased in the order: (+)-catechin > hydroalcoholic fraction > CP-13 > aqueous fraction > EtOH extract.

Espécies de Byrsonima, família Malpighiaceae, são popularmente conhecidas como "murici". Existem várias propriedades atribuídas às folhas de espécies de Byrsonima incluindo febrífuga, no tratamento de disfunções gastrintestinais e doenças de pele. Neste trabalho avaliamos a atividade antimicrobiana dos extratos das folhas de Byrsonima fagifolia, B. basiloba e B. intermedia usando o método de difusão em disco. Os resultados obtidos mostraram que os extratos metanólicos das folhas apresentaram atividade antimicrobiana contra todos os microrganismos testados.

Byrsonima species, family Malpighiaceae, is popularly known as "murici". There are several properties attributed to the leaves of Byrsonima species including febrifuge, to treat gastrointestinal dysfunctions and skin diseases. In this work, the antimicrobial activity of Byrsonima fagifolia, B. basiloba and B. intermedia extracts obtained from the leaves were evaluated by using the disc-diffusion method. The results obtained showed that the methanol extracts of leaves had presented antimicrobial activity against all the microorganisms tested.

Mycobacterium tuberculosis is responsible for over 8 million cases of tuberculosis (TB) annually. Natural products may play important roles in the chemotherapy of TB. The immunological activity of Davilla elliptica chloroform extract (DECE) was evaluated in vitro by the determination of hydrogen peroxide (H2O2), nitric oxide (NO), and tumor necrosis factor-alpha (TNF-alpha) release in peritoneal macrophages cultures. DECE was also tested for its antimycobacterial activity against M. tuberculosis using the microplate alamar blue assay. DECE (50, 150, 250 µg/ml) stimulated the production of H2O2 (from 1,79 ± 0,23 to 7,27 ± 2,54; 15,02 ± 2,86; 20,5 ± 2,1 nmols) (means ± SD), NO (from 2,64 ± 1,02 to 25,59 ± 2,29; 26,68 ± 2,41; 29,45 ± 5,87 µmols) (means ± SD) and TNF-alpha (from 2,44 ± 1,46 to 30,37 ± 8,13; 38,68 ± 1,59; 41,6 ± 0,90 units/ml) (means ± SD) in a dose-dependent manner and also showed a promising antimycobacterial activity with a minimum inhibitory concentration of 62,5 µg/ml. This plant may have therapeutic potential in the immunological and microbiological control of TB.

Neea theifera Oerst. (Nyctaginaceae) é amplamente utilizada na medicina popular brasileira para tratamento de úlceras gástricas e inflamação. A investigação fitoquímica das folhas de Neea theifera permitiu o isolamento e identificação da nova flavona luteolina-7-O-[2''-O-(5'''-O-feruloil)- beta-D-apiofuranosil]-beta-D-glucopiranosídeo (1) além dos oito compostos conhecidos vitexina, isovitexina, isoorientina, orientina, vicenina-2, crisoeriol, apigenina e luteolina. A identificação química foi realizada por métodos espectroscópicos incluindo RMN-2D, bem como análises no UV e IES-EM.

Neea theifera Oerst. (Nyctaginaceae) is widely used in Brazilian folk medicine for the treatment of gastric ulcers and inflammation. Phytochemical investigation of the leaves of Neea theifera afforded the isolation of the new flavone luteolin-7-O-[2''-O-(5'''-O-feruloyl)- beta-D-apiofuranosyl]-b-D-glucopyranoside (1) besides the eight-known compounds vitexin, isovitexin, isoorientin, orientin, vicenin-2, chrysoeriol, apigenin and luteolin. Their chemical identification was established by NMR spectroscopic methods including 2D-NMR, as well as UV and ESI-MS analyses.

High-speed counter-current chromatography (HSCCC) is a major tool for the fast separation of natural products from plants. It was used for the preparative isolation of the flavonoid monoglucosides present in the aerial parts of the Davilla elliptica St. Hill. (Dilleniaceae). This species is used in Brazilian folk medicine for the treatment of gastric disorders. The optimum solvent system used was composed of a mixture of ethyl acetate-n-propanol-water (140:8:80, v/v/v) and led to a successful separation of quercetin-3-O-alpha-L-rhamnopyranoside and myricetin-3-O-alpha-L-rhamnopyranoside in approximately 3.0 hours with purity higher than 95%. Identification was performed by ¹H NMR, 13C NMR and HPLC-UV-DAD analyses.