Parâmetros de qualidade físico-químicos e avaliação da atividade antioxidante de folhas de Plectranthus barbatus Andr. (Lamiaceae) submetidas a diferentes processos de secagem

Abstract

Quality of the leaves of Plectranthus barbatus Andr. (Lamiaceae) dried in solar dryer and oven. This paper describes the physicochemical composition, the evaluation of the antioxidant activity by free DPPH radicals using the scavenging method, the determination of flavonoids and total phenolic compounds of ethanol, acetone and aqueous extracts of the medicinal plant Plectranthus barbatus Andr. (Lamiaceae), dehydrated in solar dryer and circulation oven at 60 °C. Water activity rates for two drying methods were below the minimum necessary for growth and toxin production of important food pathogens. Physicochemical results showed that both processes were effective in the dehydration of P. barbatus. The results demonstrated that the acetone (over) and ethanol (over and solar dryer) extracts showed the highest content of total phenols. The ethanol extract (over) showed the highest amount of flavonoids and better antioxidant activity (75.71 ± 10.57 µg L -1 ).

Anatomia comparada, histoquímica e fitoquímica dos órgãos vegetativos de espécies do gênero Ocimum L. (Lamiaceae)

“…5O e 5P) no parênquima da nervura central, no parênquima do mesofilo, no colênquima angular do pecíolo e no parênquima medular do caule. As três espécies em estudo apresentam compostos antioxidantes, dentre os quais se destacam os compostos fenólicos, que também é encontrado em outra espécie da família Lamiaceae como Origanum vulgare L. (GONÇALVES et al, 2015) e Plectranthus barbatus (SILVA et al, 2016). Os compostos fenólicos se destacam por suas propriedades antioxidantes, anti-inflamatórias, protetora de órgãos vitais, incluindo o sistema cardiovascular (HITZ et al, 2018).…”

Phytochemical characterization and biological activities of Plectranthus barbatus Andrews

“…P. barbatus main constituents isolated from different parts of this species are diterpenoids, and these phytochemicals are responsible for many described biological activities (Alasbahi and Melzig, 2010). However, the presence of phenolic compounds in P. barbatus extracts has been reported in several studies (Brito et al, 2018, Ganash & Qanash, 2018, Shaheen et al, 2017, Silva et al, 2016, Rodrigues et al, 2016. Thus, in order to elucidate the biological activities of P. barbatus leaves extracts that contains phenolic compounds, here we conducted the evaluation of ConA (stimulated control) [128.63 pg.mL -1 (55.79 pg.mL -1 -387.76 pg.mL -1 )].…”

“…However, this compound has a water-insoluble nature that limits its clinical utility (Alasbahi and Melzig, 2010). Other phytochemicals such as the phenolic derivatives nepetoidins A and B (Grayer et al, 2003) and rosmarinic acid (Falé et al, 2011) were also found in P. barbatus composition (Silva et al, 2016). Phenolic plant-derived compounds comprise the composition of several classes of molecules such as simple phenolics, phenolic acids, coumarins, flavonoids, hydrolysable and condensed tannins, stilbenes, lignans and lignins (Silva et al, 2019) and, some of these have already been identified in P. barbatus extracts (Borges et al, 2020;Ezeonwumelu et al, 2019;Rodrigues et al, 2016).…”

Estudo da influência da temperatura de secagem e solvente extrator na capacidade antioxidante de folhas Plantago major

“…Estudos realizados com produtos naturais têm demonstrado a influência da temperatura de secagem e do solvente extrator na atividade antioxidante e na extração de compostos bioativos [23][24][25][26] .…”