Characterisation of phenolic compounds by UPLC-QTOF-MS/MS of geopropolis from the stingless bee Melipona subnitida (jandaíra).

INTRODUCTION: Melipona subnitida Ducke (jandaíra) is a stingless bee native to north-eastern Brazil, which produces geopropolis, a mixture of beeswax, plant resins, pollens and earth that is used for sealing beehives. OBJECTIVE: To extend the knowledge on phenolic compounds in fractions obtained by C18-solid phase extraction (SPE) of nine geopropolis samples from Melipona subnitida collected at different times. METHODOLOGY: Chromatographic profiles of nine samples of geopropolis from jandaíra were analysed by ultra-performance liquid chromatography coupled with a diode array detector and quadrupole time-of-flight mass spectrometry (UPLC-DAD-QTOF-MS/MS) and combined with the use of data-independent acquisition (MSE) for the profiling and structural characterisation of the phenolic compounds. The isolated compound was identified by nuclear magnetic resonance of hydrogen and carbon (1 H- and 13 C-NMR). RESULTS: The present study with geopropolis of jandaíra resulted in the characterisation of 51 phenolics by UPLC-DAD-QTOF-MS/MS: four galloyl glucosides, one ellagic acid, 11 acyl-hexosides, 23 acyl-galloyl-hexosides and 12 flavonoids. The structures of two compounds (1,6-di-O-(E)-coumaroyl-2-O-galloyl-ß-d-glucopyranoside and 1-O-cinnamoyl-6-O-(E)-coumaroyl-2-O-galloyl-ß-d-glucopyranoside) were established by 1 H and the attached proton test (APT) experiments as well as high-resolution electrospray ionisation mass spectroscopy (HR-ESI-MS) analysis. CONCLUSION: The geopropolis of jandaíra showed phenolic compounds galloyl hexosides, ellagic acid, acyl-(cinnamoyl/coumaroyl)-hexosides, acyl-(cinnamoyl/coumaroyl)-galloyl-hexosides and flavonoids (aglycones and acylated-O-glycosides).

Identification of flavonoids in Hymenaea martiana Hayne (Fabaceae) by HPLC-DAD-MSn analysis.

Hymenaea martiana is a native tree known in Brazil as 'jatobá' and used in folk medicine to treat pain and inflammation. The aim of this work was to identify the flavonoids present in the crude ethanolic extract and ethyl acetate fraction using HPLC-DAD and LC-MSn analysis. The ethanolic extract was partitioned to obtain the ethyl acetate fraction. The analysis of astilbin content also was carried out by HPLC analysis. HPLC-DAD-ESI/MSn analysis of the ethanolic extract and ethyl acetate fraction revealed the presence of eleven peaks in the chromatograms, and all these peaks were identified: taxifolin, eucryphin, astilbin and 3 diastereoisomers, engeletin and 2 diastereoisomers, quercitrin and 2,6,3',4'-tetrahydroxy-2-benzylcoumaran-3-one. The ethyl acetate fraction had a higher astilbin concentration (151.87 µg/mL) than the ethanolic extract (40.13 µg/mL). In conclusion, the species could be considered a good source of flavonoids, which can be related to the main chemotaxonomic markers for the genus Hymenaea.

Antioxidant and Antihypertensive Effects of a Chemically Defined Fraction of Syrah Red Wine on Spontaneously Hypertensive Rats.

A particularly phenolic-rich fraction extracted from red wine from the São Francisco valley (Northeastern Brazil) was chemically characterized and its hypotensive and antioxidant effects on spontaneously hypertensive rats were studied both in vitro and in vivo. The liquid-liquid pH dependent fractionation scheme afforded a fraction with high content of bioactive phenolics such as flavonols, flavonol glycosides, phenolic acids and anthocyanins, whose identities were confirmed by liquid chromatography coupled to mass spectrometry analysis. Pretreatment of spontaneously hypertensive rats with this wine fraction at doses of 50 and 100 mg/kg by gavage. for 15 days was able to decrease mean arterial pressure and heart rate as well as decrease serum lipid peroxidation. The fraction at concentrations of 0.01-1000 µg/mL induced concentration-dependent relaxation of isolated rat superior mesenteric artery rings pre-contracted with phenylephrine and this effect was not attenuated by endothelium removal. Our results demonstrate it is possible for phenolic constituents of red wine that are orally bioavailable to exert in vivo hypotensive and antioxidant effects on intact endothelial function.

Geopropolis gel for the adjuvant treatment of candidiasis - formulation and in vitro release assay

ABSTRACT The geopropolis produced by the stingless bee Melipona subnitida (popularly called "jandaíra" in Brazil) is a mixture of resin, wax, and mud. This study analyzed the antifungal activity of the geopropolis extract from Candida spp., developed a gel formulation with this extract and analyzed the delivery of bioactives (kinetics release) in the formulation and their chemical profile by UHPLC-PDA-qTOF-MS/MS. Three different gels were prepared using the geopropolis extract, carbomer, propylene glycol, and water. Formulations with different amounts of propylene glycol were investigated. Physical, visual, pH, viscosity, adhesion, spreadability, leakage, and in vitro release tests were performed in the proposed formulations. Antifungal tests with the geopropolis ethanolic extract were carried out against six Candida species. The chemical profile of the geopropolis extract and compounds released from the formulations were analyzed after the release test. The formulations had a pH between 4.6 and 4.8 and viscosity between 535,600 and 920,400 cPs. The geopropolis extract presented excellent antifungal activity against the tested yeasts. The results of the release test in semipermeable cellulose membrane showed that all formulations containing 5%, 10% and 40% propylene glycol presented release of geopropolis extract. For adhesion and leakage tests, the gel formulation with 5% propylene glycol was more effective. Both geopropolis ethanolic extract and the liquid obtained in the release test showed the presence of flavonoids (flavonol/flavone, flavanone, and chalcones). Gel formulations with geopropolis extract that are rich in flavonoids are promising as an adjuvant treatment of vaginal candidiasis.