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1.
Bioresour Technol ; 307: 123223, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32220818

RESUMO

In this study, crude oils extracted from spent coffee grounds (SCG) and olive pomace (OP) were used as raw-material to synthesize low-calorie triacylglycerols, either by acidolysis with capric acid, or by interesterification with ethyl caprate, in solvent-free media, catalyzed by sn-1,3 regioselective lipases. The Rhizopus oryzae lipase (ROL) was immobilized in magnetite nanoparticles (MNP-ROL) and tested as novel biocatalyst. MNP-ROL performance was compared with that of the commercial immobilized Thermomyces lanuginosus lipase (Lipozyme TL IM). For both oils, Lipozyme TL IM preferred interesterification over acidolysis. MNP-ROL catalyzed reactions were faster and acidolysis was preferred with yields of c.a. 50% new triacylglycerols after 3 h acidolysis of OP or SCG oils. MNP-ROL was very stable following the Sadana deactivation model with half-lives of 163 h and 220 h when reused in batch acidolysis and interesterification of OP oil, respectively.


Assuntos
Nanopartículas de Magnetita , Petróleo , Catálise , Café , Enzimas Imobilizadas , Esterificação , Lipase , Lipídeos , Azeite de Oliva
2.
Phytochem Anal ; 29(5): 432-445, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29479742

RESUMO

INTRODUCTION: Piper amalago has a distribution from Mexico to Brazil; their aerial parts have been used in folk medicine to treat diuretic and kidney diseases. OBJECTIVE: The purpose of this study was to obtain a deeper understanding of the chemical composition of essential oils (EOs) extracted from both the leaves and stems of P. amalago, compare them, and evaluate their antilithiasic activity and acute toxicity. METHODOLOGY: Extraction was performed by hydrodistillation, whereas chemical characterisation by two-dimensional gas chromatography coupled with rapid-scanning quadrupole mass spectrometry (GC×GC/qMS). The antilithiasic activity was evaluated by the effect of the EOs on calcium oxalate crystallisation in vitro. The turbidity index and the number of crystals formed were determined and used as an estimative of the activity. In the acute toxicity assay, the effects of a single oral dose of the EOs in Wistar rats were determined. General behaviour, adverse effects, and mortality were determined. RESULTS: A total of 322 compounds were identified in the EOs. The sesquiterpenes displayed the highest contribution in leaves EOs among which included bicyclogermacrene and δ-cadinene. Sesquiterpenes and oxygenated sesquiterpenes displayed the highest contribution in EOs from stems, among which included bicyclogermacrene and α-cadinol. The EOs demonstrated an excellent action on the crystals growth inhibition, and the oral dose tested did not induce significant changes in the parameters for acute toxicity. CONCLUSION: The oils have a high chemical complexity, and there are differences between their compositions, which could explain the observed differences in antilithiasic activity. The findings support the use of this plant in folk medicine to treat kidney diseases.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Cálculos Renais/tratamento farmacológico , Óleos Voláteis/química , Óleos Voláteis/uso terapêutico , Piper/química , Administração Oral , Animais , Oxalato de Cálcio/química , Cristalização , Humanos , Óleos Voláteis/administração & dosagem , Óleos Voláteis/toxicidade , Folhas de Planta/química , Caules de Planta/química , Ratos Wistar , Testes de Toxicidade Aguda
3.
J Agric Food Chem ; 61(28): 6812-21, 2013 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-23815555

RESUMO

This work studied fast pyrolysis as a way to use the residual fiber obtained from the shells of coconut ( Cocos nucifera L. var. Dwarf, from Aracaju, northeastern Brazil). The bio-oil produced by fast pyrolysis and the aqueous phase (formed during the pyrolysis) were characterized by GC/qMS and GC×GC/TOF-MS. Many oxygenated compounds such as phenols, aldehydes, and ketones were identified in the extracts obtained in both phases, with a high predominance of phenolic compounds, mainly alkylphenols. Eighty-one compounds were identified in the bio-oil and 42 in the aqueous phase using GC/qMS, and 95 and 68 in the same samples were identified by GC×GC/TOF-MS. The better performance of GC×GC/TOF-MS was due to the possibility of resolving some coeluted peaks in the one-dimension gas chromatography. Semiquantitative analysis of the samples verified that 59% of the area on the chromatogram of bio-oil is composed by phenols and 12% by aldehydes, mainly furfural. Using the same criterion, 77% of the organic compounds in the aqueous phase are phenols. Therefore, this preliminary assessment indicates that coconut fibers have the potential to be a cost-effective and promising alternative to obtain new products and minimize environmental impact.


Assuntos
Cocos/química , Frutas/química , Temperatura Alta , Óleos de Plantas/química , Aldeídos/análise , Biocombustíveis/análise , Brasil , Cromatografia Gasosa , Cromatografia Gasosa-Espectrometria de Massas , Cetonas/análise , Espectrometria de Massas , Fenóis/análise , Extratos Vegetais/química
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