ABSTRACT
In this study we report the characterization of the volatile compounds of Laurencia dendroidea. Solvent extracts (dichloromethane and methanol), hydrodistillation extracts and headspace solid-phase microextraction samples were obtained and analyzed by GC-MS. Forty-six volatile components were identified in L. dendroidea, among them hydrocarbons, alcohols, phenols, aldehydes, ketones, acids, esters and terpenes.
ABSTRACT
Two known sesquiterpenes (1R*,2S*,3R*,5S*,8S*,9R*)-2,3,5,9-tetramethyltricyclo[6.3.0.0(1,5)]undecan-2-ol and (1S*,2S*,3S*,5S*,8S*,9S*)-2,3,5,9-tetramethyltricyclo-[6.3.0.0(1,5)]undecan-2-ol were isolated for the first time from the essential oil of the red seaweed Laurencia dendroidea collected in the Brazilian coast. These compounds were not active against eight bacteria strains and the yeast Candida albicans, but showed some antioxidant activity. Both compounds were also found in other seaweed species showing that they are not exclusive taxonomic markers to the genus Laurencia.
ABSTRACT
O oceano apresenta uma vasta diversidade de espécies, entre elas as algas marinhas, as quais são usadas principalmente como fonte de alimentos, de produtos industriais e para uso medicinal. Considerando a biodiversidade encontrada, são poucos os estudos que verificam a composição química e atividade biológica de algas. Desta forma, o presente trabalho descreve especialmente compostos do metabolismo primário (lipídios, proteínas e aminoácidos), composição química volátil, e potencial antioxidante e antimicrobiano de quatro espécies de algas vermelhas da costa brasileira (Laurencia filiformis, Laurencia intricata, Plocamium brasiliense e Ochtodes secundiramea). As análises de lipídeos revelaram que estas algas são ricas em ácidos graxos poliinsaturados ω3 e ω6, mas que apresentam o ácido palmítico como majoritário. O teor de proteínas encontrado é considerável e aproximadamente 50% da composição de aminoácidos é de aminoácidos essenciais. Para extrair os compostos voláteis das algas selecionadas para o estudo, três métodos foram utilizados: arraste a vapor, extração por solvente e HS-SPME. A caracterização química dos compostos voláteis deu-se principalmente pela utilização de cromatografia gasosa acoplada à espectrometria de massas (CG-EM). Ainda foram isolados e identificados dois compostos majoritários do óleo essencial de L. filiformis, o (-)-7-epi-silfiperfolan-6β-ol e o (-)-silfiperfolan-7β-ol, e quatro compostos do extrato acetona/água de P. brasiliense, o 3,4-eritro-7-diclorometil-3-metil-3,4,8-tricloro-1,5(E),7(E)-octatrieno; o 3,4-eritro-7-diclorometil-3-metil-3,4,8-tricloro-1,5(E),7(Z)-octatrieno; o 3,4-eritro-1-bromo-7-diclorometil-3-metil-3,4,8-tricloro-1(E),5(E),7(E)-octatrieno e o 3,4-eritro-1-bromo-7-diclorometil-3-metil-3,4,8-tricloro-1(E),5(E),7(Z)-octatrieno, utilizando diferentes técnicas cromatográficas, como CCDP e CLAE, para isolamento, e técnicas espectroscópicas (RMN uni e bidimensionais) e espectrométricas (HRMS e EIMS) para análise...
The ocean provides large diversity of species, among them the seaweeds, which are mainly used as food, industrial products and as medicine. Considering the biodiversity, there are only few studies which analize the algae volatile compounds and their biological activity. So that, this work describes specially compounds from the primary metabolism (lipids, proteins and amino acids), chemical volatile composition, and antioxidant and antimicrobial potencies of four red algae of the Brazilian coast (Laurencia filiformis, Laurencia intricata, Plicamium brasiliense and Ochtodes secundiramea). The lipid analysis showed that these algae have ω3 and ω6 polyunsaturated fatty acids, but the palmitic acid is the most abundant. The protein content observed is considerable and approximately 50% of the amino acid composition is of essential amino acids. To extract the volatile organic compounds from the algae selected for this study, three methods were used: hydrodestilation, solvent extraction and HS-SPME. For chemical characterization of the volatile compounds, the technique used was gas chromatography coupled with mass spectrometry (GC-MS). In addition, the two most abundant compounds from the essential oil of L. filiformis, the (-)-7-epi-silphiperfolan-6β-ol and the (-)-silphiperfolan-7β-ol, and four compounds of the aceton/water extract of P. brasiliense the 3,4-erythro-7-dichloromethyl-3-methyl-3,4,8-trichloro-1,5(E),7(E)-octatriene; the 3,4-erythro-7-dichloromethyl-3-methyl-3,4,8-trichloro-1,5(E),7(Z)-octatriene; the 3,4-erythro-1-bromo-7-dichloromethyl-3-methyl-3,4,8-trichloro-1(E),5(E),7(E)-octatriene and the 3,4-erythro-1-bromo-7-dichloromethyl-3-methyl-3,4,8-trichloro-1(E),5(E),7(Z)-octatriene, were isolated and identified using different chromatographic techniques like preparative TLC and HPLC for isolation and spectroscopic (NMR uni and bidimensional) and spectrometric techniques (HRMS and EIMS) for analysis. The antioxidant activity of the essential oils, of...