Optimization of ultrasound-assisted extraction of phenolics from Asparagopsis taxiformis with deep eutectic solvent and their characterization by ultra-high-performance liquid chromatography-mass spectrometry

Abstract

Asparagopsis taxiformis is a significant source of phenolics. Owing to the incessant demand of green extraction procedures for phenolics from A. taxiformis, ultrasound-assisted extraction (UAE) using deep eutectic solvents (DESs) was optimized. Among the tested DESs, betaine-levulinic acid afforded the highest total phenolic content (TPC). Moreover, the optimal extraction conditions elucidated from single-factor and response surface methodologies comprised a 52.41°C ultrasonic temperature, 46.48% water content of DES, and 26.99 ml/g liquid-to-solid ratio. The corresponding TPC (56.27 mg GAE/100 g DW) and antioxidant ability fitted the predicted values. UAE afforded superior TPC and antioxidant abilities with DESs than with traditional solvents. Using UHPLC-MS, seven phenolic acids, 18 flavonoids, and two bromophenols were identified and quantified. DES-UAE afforded the highest phenolic compound number (26) and sum of contents. These results disclose the high extraction efficiency of DES-UAE for A. taxiformis phenolics and provide a basis for the higher-value application of this species.

Fermentation of Betaphycus gelatinum Using Lactobacillus brevis: Growth of Probiotics, Total Polyphenol Content, Polyphenol Profile, and Antioxidant Capacity

“…Peak 26 displayed the parent ion [M–H] − at m / z 250.74 and fragment ions at m / z 81.37 and 78.51, which was consistent with the MS data of 2,4-dibromophenol reported in a previous study [ 46 ]. The parent and product ions of peak 27 were observed at m / z 330.60 and 81.35, respectively, which were in agreement with the MS data of 2,4,6-tribromophenol reported previously [ 47 ].…”

“…Trans -cinnamic acid, caffeic acid, ferulic acid, rosmarinic acid, ellagic acid, quercetin, myricetin, taxifolin, isoquercitrin, and vitexin were detected in Kappaphycus alvarezii by HPLC-MS [ 4 ]. Phenolic acids (including ethyl vanillin, 2-hydroxybenzoic acid, ferulic acid, rosmarinic acid, and trans -cinnamic acid), flavan-3-ols (gallocatechin and epigallocatechin), and cyanidin were found in the red seaweed Asparagopsis taxiformis using HPLC-MS [ 46 ]. Epicatechin gallate and hinokiflavone were abundant in the brown seaweeds Anthophycus longifolius and Sargassum polycystum , respectively [ 9 , 48 ].…”

“…Taxifolin-O-rhamnoside, kaempferol-O-glucoside, myricetin-O-rhamnoside, apigenin-O-glucoside, quercetin-O-hexoside, and isorhamnetin-O-glucoside were identified in brown seaweeds by HPLC-MS [ 43 ], which may have been taxifolin-7-O-rhamnoside, kaempferol-3-O-glucoside, myricetin-3-O-rhamnoside (myricitrin), apigenin-7-O-glucoside (cosemetin), quercetin-3-O-galactoside (hyperoside), and isorhamnetin-3-O-glucoside, respectively, or their isomers. Simple bromophenols (including 2,4-dibromophenol and 2,4,6-tribromophenol) and complex bromophenols were found in several red seaweeds, including Asparagopsis taxiformis , Polyopes lancifolia, and Rhodomela confervoides [ 8 , 46 , 47 ]. These polyphenols were identified in Betaphycus gelatinum for the first time.…”

Macroalgal microbiomes unveil a valuable genetic resource for halogen metabolism

“…Despite studies demonstrating the production of phenolic compounds in At extract, the precise chemical structures of these metabolites remain elusive [ 72 ]. However, two bromophenols have recently been identified in At [ 73 ]. In the present study, genes encoding glutathionyl-hydroquinone reductases (EC 1.8.5.7) (Fig.…”

Enzyme-Assisted Coextraction of Phenolics and Polysaccharides from Padina gymnospora

“…Although these methods efficiently extract the target compounds, the use of organic solvents and chemicals is not green and can degrade sensitive phenolic components, making multiple-product recovery unfeasible. Other methods such as ultrasound- [16][17][18] and microwave-assisted [19,20] extraction have been proposed to improve compound yields and shorten extraction times, as they employ ultrasound energy or electromagnetic waves to break down the cellular structure of the seaweed, enhancing the release of these compounds [19]. However, the industrial application of these processes is limited due to challenges at large-scale production [21].…”