Zeb Liaqat, Gerhardt Anne Sophie, Johannesen Benjamin Alexander, Underhaug Jarl, Jordheim Monica
Department of Chemistry, University of Bergen, Bergen 5007, Norway.
ACS Sustain Chem Eng. 2024 Sep 26;12(40):14921-14929. doi: 10.1021/acssuschemeng.4c06736. eCollection 2024 Oct 7.
This case study introduces a green, 1 h single-step method using water-rich natural deep eutectic solvent (WRNADES) for ultrasound-assisted extraction (UAE) of polyphenols from, a commercially cultivated brown seaweed. The extraction efficiency was evaluated using a selective quantitative NMR method (s-qNMR) and the traditional nonselective colorimetric total phenolic content assay (TPC). Initial 6 h extractions in traditional solvents (methanol, ethanol, acetone, and ethyl acetate) showed a 40-60% increase in polyphenolic yields in 50% aqueous solutions measured by the TPC method. Six different water-rich (50%) NADES (WRNADES) combinations were tested (choline chloride/betaine with lactic acid, citric acid, and 1,3-butanediol), with betaine and 1,3-butanediol (1:1) proving most effective. Parameters for the WRNADES were optimized using Box-Behnken design response surface methodology, resulting in a 1:20 w/w biomass to solvent ratio and a 1 h extraction time at 50 °C. The WRNADES extraction process was refined into a scalable, single-step procedure and compared with traditional solvent extractions (6 h, 50% aqueous methanol and acetone). A final XAD-7 polyphenol recovery step was included in all extractions. The optimized WRNADES extraction yielded 15.97 mg GAE/g of the dry weight recovered polyphenolic extract (s-qNMR), exceeding the 6 h 50% aqueous methanol (12.4 mg GAE/g) and acetone (11.4 mg GAE/g) extractions. Thus, the UAE-WRNADES method presented in this case study provides a cost-effective, sustainable, and eco-friendly alternative for the extraction of phenolic compounds from seaweed. It promotes the development of environmentally friendly production processes within the seaweed biorefinery.
本案例研究介绍了一种绿色、耗时1小时的单步方法，该方法使用富含水的天然低共熔溶剂（WRNADES），通过超声辅助提取（UAE）从一种商业种植的褐藻中提取多酚。使用选择性定量核磁共振方法（s-qNMR）和传统的非选择性比色法总酚含量测定（TPC）对提取效率进行了评估。在传统溶剂（甲醇、乙醇、丙酮和乙酸乙酯）中进行的初始6小时提取显示，通过TPC方法测定，在50%水溶液中多酚产量提高了40-60%。测试了六种不同的富含水（50%）的低共熔溶剂（WRNADES）组合（氯化胆碱/甜菜碱与乳酸、柠檬酸和1,3-丁二醇），结果表明甜菜碱和1,3-丁二醇（1:1）最为有效。使用Box-Behnken设计响应面方法对WRNADES的参数进行了优化，得到了1:20 w/w的生物质与溶剂比以及在50°C下1小时的提取时间。WRNADES提取过程被优化为一种可扩展的单步程序，并与传统溶剂提取（6小时，50%甲醇水溶液和丙酮）进行了比较。所有提取过程都包括一个最终的XAD-7多酚回收步骤。优化后的WRNADES提取得到了15.97 mg GAE/g干重的回收多酚提取物（s-qNMR），超过了6小时50%甲醇水溶液（12.4 mg GAE/g）和丙酮（11.4 mg GAE/g）提取的产量。因此，本案例研究中提出的UAE-WRNADES方法为从海藻中提取酚类化合物提供了一种经济高效、可持续且环保的替代方法。它促进了海藻生物炼制中环境友好型生产工艺的发展。
