Haematococcus pluvialis (H. pluvialis) microalgae are well known for their high content of astaxanthin, which is a super potent antioxidant with various remedial effects. Ionic liquids (ILs) have been proposed as a promising solvent to permeabilize the robust microalgal cell wall for an effective extraction of bioactive compounds. Nonetheless, the removal of ILs from the extracted compounds requires the additional treatment steps that complicate the overall extraction process and the recycling of ILs. To address these shortcomings, we demonstrated a sustainable extraction system that utilizes CO₂-based alkyl carbamate ILs to permeate H. pluvialis cells and extract astaxanthin. This class of ILs is readily distillable for an easy recovery of ILs from the extraction medium. Among the tested CO₂-based alkyl carbamate ILs [dimethylammonium dimethylcarbamate (DIMCARB), dipropylammonium dipropylcarbamate (DPCARB), dibutylammonium dibutylcarbamate (DBCARB) and diallyammonium diallycarbamate (DACARB)], DIMCARB gave the best performance of astaxanthin extraction. The optimized extraction conditions [100% (w/w) of DIMCARB, 75 min and 45°C] resulted in the high yield of astaxanthin (27.99 mg/g). The capability of DIMCARB to permeabilize the amorphous trilayered structure of cell wall was verified by the presence of pores on the cell surface of H. pluvialis as shown in the microscope images. The performance and recyclability of DIMCARB extraction system were also evaluated by conducting three successive rounds of astaxanthin extraction with the recycled DIMCARB solutions. In addition, the antioxidant capacity of the extracted astaxanthin was well retained, showing that this type of distillable IL was suitable for the extraction of phytonutrients from algal source.

雨生红球菌（H. pluvialis）微藻以虾青素的含量高而闻名，虾青素是一种具有多种修复作用的超强抗氧化剂。离子液体（ILs）已被提出作为一种有希望的溶剂，可以透透坚固的微藻细胞壁，从而有效地提取生物活性化合物。尽管如此，从提取的化合物中去除IL仍需要额外的处理步骤，这会使整个提取过程和IL的回收变得复杂。为了解决这些缺点，我们展示了一种可持续的提取系统，该系统利用基于CO ₂的氨基甲酸烷基酯ILs渗透到幽门螺杆菌中细胞并提取虾青素。此类IL易于蒸馏，以便从提取培养基中轻松回收IL。在测试的基于CO ₂的氨基甲酸烷基酯ILs [二甲基氨基甲酸二甲基铵（DIMCARB），二丙基氨基甲酸二丙基铵（DPCARB），二丁基氨基甲酸二丁基铵（DBCARB）和十二烷基氨基甲酸二铵铵（DACARB）]中，DIMCARB提取虾青素的性能最佳。优化的提取条件[DIMCARB的100％（w / w），75分钟和45°C]导致虾青素的高收率（27.99 mg / g）。DIMCARB通透细胞壁的无定形结构trilayered的能力是由孔隙的所述细胞表面上的存在验证H.生红球藻如显微镜图像所示。通过使用回收的DIMCARB溶液连续进行三轮虾青素提取，还评估了DIMCARB提取系统的性能和可回收性。此外，提取的虾青素的抗氧化能力得到了很好的保留，这表明这种可蒸馏的IL适合从藻类来源提取植物营养素。