Quantificação de salicilato de metila em quatro gêneros de polygalaceae, por CLAE-DAD

Polygalaceae is represented in Brazil by ten genera and 191 species, of which the Polygala is the most representative, characterized by the occurrence of methyl salicylate. Seventeen species of Polygalaceae have been analyzed by HPLC-DAD and the technique proved to be selective, precise, accurate, and with low limits of quantification and detection. The analysis of plant material confirmed the presence of methyl salicylate, with concentration values ​​ranging from 14.1 a 126.9 µg/g.

Phytochemical profile, toxicity and antioxidant activity of Aloysia gratissima (Verbenaceae)

Aloysia gratissima (Gill. et Hook) Tronc. (Verbenaceae) is native to South America with folk therapeutic applications for a wide range of diseases. The polyphenolic and carotenoid profile, toxicity, and antioxidant activity of aqueous extract of Aloysia gratissima were investigated. HPLC analyses showed high amounts of ferulic acid, trans-cinnamic acid and p-coumaric acid, and also trans-β- carotene and lutein which fluctuated throughout the seasons. Furthermore, the extract investigated not only exerted antioxidant activity but also inhibited lipid peroxidation. Toxicity was achieved only at the highest dose tested. Therefore, A. gratissima is a potential species for medicinal purposes.

Chemical profiling of six samples of Brazilian propolis

Six samples of Brazilian propolis from Minas Gerais and Paraná states were analyzed to identify the constituents (GC/MS and HPLC/MS) and to determine their contents (HPLC and external standardization). All samples contained characteristic constituents of green propolis, but the samples from Minas Gerais had higher contents of prenylated phenylpropanoids and caffeoylquinic acids. Kaempferide and two other flavonoids were among the major constituents of the samples from Minas Gerais. Luteolin 5-O-methyl ether was detected only in samples from Paraná. Baccharis dracunculifolia was a source of resins for all samples analyzed, but the samples from Paraná had more complex plant origin.

Resíduos de pesticidas em águas superficiais de área de nascente do Rio São Lourenço-MT: validação de método por extração em fase sólida e cromatografia líquida

A multiresidue method using HPLC/DAD for the determination of fourteen pesticides in water based on SPE, using SDVB (styrene divynilbenzene copolymer) as adsorbent was validated. Recoveries from 61 to 120%, relative standard deviation between 2 and 15% and detection limits from 0.07 to 0.75 µg L-1 were obtained. It was applied to 66 surface water samples collected in a degraded area at the headwaters of São Lourenço river, Mato Grosso, Brazil. Eight pesticides were detected in concentrations ranging from 0.15 to 35.25 µg L-1. Considering ecotoxicological data, carbendazim and carbofuran may represent a risk to aquatic organisms. These results draw attention to the contamination of this vulnerable degraded area.

Atividade de extratos de Arrabidaea chica (Humb. & Bonpl.) Verlot obtidos por processos biotecnológicos sobre a proliferação de fibroblastos e células tumorais humanas

Arrabidaea chica (H&B) Verlot is a plant popularly known as Pariri and this species is a known source of anthocyanins, flavonoids and tannins. This report describes an approach involving enzymatic treatment prior to extraction procedures to enhance A chica crude extract anticancer activity. Anticancer activity in human cancer cell lines in vitro using a 48 h SRB cell viability assay was performed to determine growth inhibition and cytotoxic properties. The final extraction yield without enzyme treatment was higher (24.28%) compared to the enzyme-treated material (19.03%), with an enhanced aglycones anthocyanin ratio as determined by HPLC- DAD and LC-MS with direct infusion.

Aspectos analíticos e regulatórios na determinação de resíduos de macrolídeos em alimentos de origem animal por cromatografia líquida associada à espectrometria de massas

This is an overview of LC-MS techniques applied for macrolide determination in food, including sample preparation and method validation, as well as the policies adopted by international agencies regarding their presence in food. Techniques for the analysis of macrolides in food normally include solid phase or liquid-liquid extraction followed by HPLC. UHPLC presents advantages in running time, detectability and solvent consumption. Triple-quadrupoles are the most common analyzers in instruments used for the determination of contaminants in food, but time-of-flight and ion-trap spectrometers have been successfully applied for analyses focusing on the investigation of structural formula or the presence of degradation products.

Teores de trigonelina, ácido 5-cafeoilquínico, cafeína e melanoidinas em cafés solúveis comerciais brasileiros

Commercial Brazilian regular and decaffeinated instant coffees (33 brands) were studied. The levels ranged from 0.47 to 2.15 g 100 g-1 for trigonelline, 0.38 to 2.66 g 100 g-1 for 5-caffeoylquinic acid (5-CQA), 0.24 to 4.08 g 100 g-1 for caffeine, and 0.253 to 0.476 (420 nm) for melanoidins. Variations in bioactive compound levels among batches were observed. There was no relationship between the drying process and the composition of the products. In general, Gourmet and decaffeinated coffees had higher trigonelline and 5-CQA but lower caffeine and melanoidin content than regular products.

Desenvolvimento e validação de um método analítico por espectrofotometria UV para quantificação de carvedilol

This paper reports the development and validation of a new analytical method using UV spectrophotometry to quantify carvedilol (CRV) in hydrophilic matrices and raw material. This method was shown to be linear, accurate, precise, robust and to have adequate limits of quantification and detection (LQ and LD, respectively), allowing its use in the dissolution test of hydrophilic matrices. The content of CRV determined through this method was compared with two previously validated methods based on the reference techniques of High Performance Liquid Chromatography (HPLC) and Potentiometric Titrations (PT). ANOVA confirmed the equivalence of these methods, showing no significant differences.

Improved method to obtain pfaffic acid as a marker for quality control

Pfaffic acid, a marker of Hebanthe eriantha (Brazilian ginseng), was first isolated in 1983 but is not yet commercially available. This lack of availability compromises the quality control of this plant and its derivatives. This paper proposes a process for pfaffic acid isolation from roots of H. eriantha at a purity suitable for analytical purposes. The steps involved in this process included extraction, hydrolysis, fractionation and purification by preparative HPLC. This process led to isolation of pfaffic acid with a chromatographic purity of 98.5% in a 0.25% yield from dried roots of H. eriantha; this yield is more than forty times higher than that of the current method in the literature.

Preparative separation of polyphenols from artichoke by polyamide column chromatography and high-speed counter-current chromatography

An efficient method for the rapid separation and purification of polyphenols from artichoke by polyamide column chromatography in combination with high-speed counter-current chromatography (HSCCC) was successfully built. The crude ethanol extracts from dry artichoke were first pre-separated by polyamide column chromatography and divided in two parts as sample 1 and sample 2. Then, the samples were further separated by HSCCC and yielded 7.8 mg of chlorogenic acid (compound I), 24.5 mg of luteolin-7-O-β-D-rutinoside (compound II), 18.4 mg of luteolin-7-O-β-D-glucoside (compound III), and 33.4 mg of cynarin (compound IV) with purity levels of 92.0%, 98.2%, 98.5%, and 98.0%, respectively, as determined by high-performance liquid chromatography (HPLC) method. The chemical structures of these compounds were identified by electrospray ionization-mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR).

Metabolic response induced by endophytic fungi and bacteria in H. marrubioides Epling in vitro microplants

Hyptis marrubioides Epling is a native plant from Brazilian Cerrado. In this paper, the response of in vitro microplants of this species to inoculation with bacterial and fungal endophytic isolates is evaluated. HPLC-DAD analysis showed the presence of 3,4-O-(Z)-dicaffeoylquinic acid and quercetin-7-O-glucoside as the main components. GC/MS analysis demonstrated that the sesquiterpenes τ-cadinol and caryophyllene oxide were only produced in microplants inoculated with endophytic bacteria, while methyl hexadecanoate, methyl heptadecanoate and methyl (Z,Z,Z) 9,12,15-octadecatrienoate and the triterpene methyl 3β-hydroxy-urs-12-en-28-oate were overexpressed only when the microplant was treated with endophytic fungi.

Preparação, caracterização e aplicação de fases estacionárias tipo C8 modificadas por óxidos metálicos para cromatografia líquida

This work describes three C8-stationary phases for high performance liquid chromatography based on silica metallized with ZrO2, TiO2 or Al2O3 layers, having poly(methyloctylsiloxane) immobilized onto their surfaces. The stationary phases were characterized using XRF, XAS, FTIR, SEM and elemental analysis to determine the physical characteristics of the oxide and polysiloxane layers formed on the surfaces and chromatographically to evaluate the separation parameters. The results show the changes on the silica surface and allowed proposing a structure for the oxide layer, being observed tetrahedral and octahedral structures, what is completely new in the literature. The formation of a homogeneous layer of metallic oxide (TiO2 and ZrO2) was observed on the silica. The C8-titanized and C8-aluminized stationary phases presented good chromatographic performances, with good values of asymmetry and efficiency. All stationary phase presented few loss of the polymeric layer after the HPLC, indicating that this layer is well attached on the metalized support.

Quantification of beta-lactam antibiotics in veterinary drugs: amoxicillin and ampicillin determination by high performance liquid chromatography

This work focused on the development and validation of an RP-HPLC-UV method for quantification of beta-lactam antibiotics in three pharmaceutical samples. Active principles analyzed were amoxicillin and ampicillin, in 3 veterinary drugs. Mobile phase comprised 5 mmol L-1 phosphoric acid solution at pH 2.00, acetonitrile with gradient elution mode and detection wavelength at 220 nm. The method was validated according to the Brazilian National Health Surveillance regulation, where linear range and linearity, selectivity, precision, accuracy and ruggedness were evaluated. Inter day precision and accuracy for pharmaceutical samples 1, 2 and 3 were: 1.43 and 1.43%; 4.71 and 3.74%; 2.72 and 1.72%, respectively, while regression coefficients for analytical curves exceeded 0.99. The method had acceptable merit figure values, indicating reliable quantification. Analyzed samples had active principle concentrations varying from -12 to +21% compared to manufacturer label claims, rendering the medicine unsafe for administration to animals.

Preparative separation of C19-diterpenoid alkaloids from Aconitum carmichaelii Debx by pH‑zone-refining counter-current chromatography

The technique of pH-zone-refining counter-current chromatography was successfully applied to preparatively separate three C19-diterpenoid alkaloids from the crude extracts of Aconitum carmichaelii for the first time using a two-phase solvent system of petroleum ether-ethyl acetate-methanol-water (5:5:1:9, v/v/v/v). Mesaconitine (I), hypaconitine (II), and deoxyaconitine (III) were obtained from 2.5 g of the crude alkaloids in a one-step separation; the yields were 4.16%, 16.96%, and 5.05%, respectively. The purities of compounds I, II, and III were 93.0%, 95%, and 96%, respectively, as determined by HPLC. The chemical structures of the three compounds were identified by electrospray ionization mass spectrometry (ESI-MS) and NMR.

Efeito do solvente na extração de ácidos clorogênicos, cafeína e trigonelina em Coffea arabica

In this research work the effects of four solvents and their mixtures on the extraction of chlorogenic acids, caffeine and trigonelline in crude extracts of four coffee cultivars, traditional red bourbon, IAPAR59, IPR101 and IPR108 cultivars, were investigated by UV spectrophotometry and UV spectra obtained from RP-HPLC-DAD. The experimental results and the principal component analysis of UV spectra showed that the effect of solvent extraction of the metabolites does not depend on cultivars, because the spectral characteristics are similar, but the concentrations are different. The UV and UV-DAD spectra for four simplex centroid design mixtures were also similar but the concentrations of caffeine, trigonelline and the chlorogenic acids are different and depend on the solvent used in the extraction.