Fucoxanthin and Phenolic Contents of Six Dictyotales From the Tunisian Coasts With an Emphasis for a Green Extraction Using a Supercritical CO2 Method (original) (raw)
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Seaweeds have a growing number of successful applications in the food industry, medicine and in the cosmetic industry, which increases the importance of evaluating their chemical composition. In the present study, three common Egyptian seaweeds (Dictyota dichotoma, Turbinaria decurrens and Laurencia obtusa) were collected from the Red Sea coast, Suez, Egypt. The chemical profile of the three seaweeds was studied beside the antioxidant activity of their extracts. The results indicated that the amount of carbohydrate was greater than the protein and lipid contents in the three seaweeds, with a natural richness in minerals and antioxidants besides considerable amounts of monounsaturated and polyunsaturated fatty acids, including Omega-3 and Omega-6 fatty acids. All essential amino acids for human were found in the three seaweeds, with significant amounts of aspartic and glutamic acids. Furthermore, the results of the antioxidant activity assays were consistent with the antioxidant cont...
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Macroalgae produce a large range of primary and secondary metabolites with ecological and economical importance. Studies on antioxidants from marine algae have increased notably, focusing on searching new sources of natural compounds for different applications, in which tropical species have been shown to have high potential, often improved by stressful environmental conditions during the tide cycle with periods of emersion and submersion. Therefore, in order to characterize the antioxidant activity and relate it to local environmental tide exposure, three species of brown marine algae, Canistrocarpus cervicornis, Dictyopteris delicatula, and Lobophora variegata from two beaches on the northeast coast of Brazil were studied. Dichloromethane:methanol (DCM:M) and aqueous extracts were tested for ferric reducing antioxidant power, 2,2-diphenyl-1picrylhydrazyl, and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) antioxidant assays and total phenolic compounds. Aqueous extracts of C. cervicornis showed up to 10 times major antioxidant activity and phenolic compounds than DCM:M extracts. Different characteristic of antioxidant activity were identified among the beaches, species, and extracts, in which aqueous extracts from C. cervicornis and L. variegata showed the most promising matrices for future prospection of natural antioxidants.
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Extract of Seaweed Dictyota coriacea Scavenges Superoxide Anion and Hydroxyl Radical
Food Supplements and Biomaterials for Health
In this study, we prepared the ethanol extract of Dictyota coriacea (DCEE) and investigated its ability, along with epiloliolide and 1,9-dihydroxycrenulide compounds derived from this seaweed, to eliminate superoxide anion (•O 2 −) and hydroxyl radical (•OH) through electron spin resonance spectrometry. The findings indicate that DCEE effectively scavenges both •O 2 − and •OH, while the 2 compounds target •OH only. These results support the •OH scavenging properties of DCEE and imply the presence of substances within DCEE that can also eliminate •O 2 −. Furthermore, in order to identify ingredients with antioxidant properties and ensure their safety, we fractionated DCEE into 5 fractions using solvents of varying polarities (hexane, dichloromethane, ethyl acetate, butanol, and water) and examined these fractions for 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and cytotoxicity. Among the 5 fractions, the ethyl acetate fraction exhibited the highest activity, followed by the water and dichloromethane fractions, while the hexane and butanol fractions displayed the lowest activities. With regards to cytotoxicity, all fractions except for the water fraction exhibited varying degrees of cytotoxic effects, which correlated inversely with the polarity of the solvents used. The ethyl acetate and dichloromethane fractions demonstrated superior scavenging activity but also higher cytotoxicity, whereas the butanol fraction exhibited lower cytotoxicity but the least scavenging activity. These findings suggest that D. coriacea possesses the ability to eliminate •O 2 − and •OH and propose that fractionating DCEE using water may yield antioxidant ingredients with minimal cytotoxicity.
Biochemical evaluation of antioxidant activity and polysaccharides fractions in seaweeds
Global Journal of Environmental Science and Management, 2015
In the present study ethanol and water extracts of 15 seaweeds, Dictyota dichotoma var. velutricata, Dictyota indica, Iyengaria stellata, Padina pavonia, Sargassum swartzii, Sargassum variegatum, Stoechospermum marginatum, Stokeyia indica, Jolyna laminarioides, Caulerpa taxifolia, Halimeda tuna, Ulva fasciata, Ulva lactuca, Solieria robusta, and Melanothamnus afaqhusainii, were evaluated for their antioxidant potential by ABTS or 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), superoxide and total antioxidant capacity (TAC) assays. The activity was concentration dependent and the variation in antioxidant potential was also observed by different assays in both extracts. Ethanol extract of D. dichotoma var. velutricata, D. indica and S. marginatum demonstrated highest activity by TAC assay. The antioxidant potential in organic solvent fractions of seaweeds namely P. pavonia, S. swartzii, S. marginatum and M. afaqhusainii was also determined and chloroform fraction of a...
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In this study, the influences of temperature (20, 40 and 60 °C) and extraction solvents (water, ethanol) on the ultrasound-assisted extraction of phenolics from the Adriatic macroalgae Dictyota dichotoma and Padina pavonica were studied. The extracts were analysed for major phenolic sub-groups (total phenolics, flavonoids and tannins) using spectrometric methods, while the individual phenolics were detected by HPLC. The antioxidant activities were evaluated using three methods: Ferric Reducing/Antioxidant Power (FRAP), scavenging of the stabile 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and Oxygen Radical Antioxidant Capacity (ORAC). The aim of the study was also to find the connection between the chemical composition of the extracts and their biological activity. Therefore, principal component analysis (PCA), which permits simple representation of different sample data and better visualisation of their correlations, was used. Higher extraction yields of the total phenolics, flavo...
International Journal of Pharmacy and Pharmaceutical Sciences, 2019
Objective: This work aimed to screen the antioxidant activity of marine macroalgae from the Moroccan Atlantic coast (region of El Jadida). Methods: Evaluation of the antioxidant activity of different collected species, lyophilized and extracted with a solvent mixture chloroform/methanol (2/1; v/v) was conducted according to two techniques, first by thin layer chromatography (tlc) then by spectrophotometry, using a free radical 2,2-diphenyl-1-picrylhydrazyl (dpph). The sampling on a distance of 110 km allowed to harvest 86 algal species (16 brown algae, 47 red algae, 14 green algae and 9 algae being identified). Results: The analysis by thin layer chromatography reveals an antioxidant activity in nearly half of harvested algal species (52.32 %). This activity varies depending on the concentration of the extract and in function of incubation time in the presence of dpph. The monitoring of the kinetics of degradation of dpph by spectrophotometer in the presence of extracts which were active by tlc allowed to confirm the results and select the most active algal species based on the percentage of remaining dpph in the medium after 120 min of reaction: Fucus spiralis (17.02 %), Cyctoseira ericoides (12.16 %) (Phaeophyceae), and Gracilaria multipartita (36%), Halopitys incurvus (5%) (Rhodophyceae). Conclusion:
Antioxidant activity and phytochemical analysis of a few Indian seaweed species
Antioxidant activities of crude methanol extracts and fractions of the seaweed species viz. Bryopsis plumosa (BP), Dictyopteris australis (DA) and Gracilaria pudumadamensis (GP) of Indian waters were evaluated and correlated with their phytochemical contents. In DPPH assays the most promising antioxidant sample was the crude methanol extract (BP M), which was comparable with standard antioxidant BHT. In the superoxide radical activity assays no sample in the group was as active as BHT, however the promising ones were DA M , DA E and GP M , GP E , GP H (subscripts M, E and H stand for the respective methanol extracts and their ethyl acetate and hexane fractions). In the Fe 2+ chelating activity assays EDTA showed far stronger activity than those of the promising samples. In reducing power assays BP M , BP E , and BP H showed comparable activity with BHT at a concentration 0.5 mg/mL. Thus these seaweed species would be of potential utility as a source of natural antioxidants.