College of Food Science and Engineering, Ocean University of China, Qingdao, China.
Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
J Sci Food Agric. 2021 Apr;101(6):2576-2583. doi: 10.1002/jsfa.10887. Epub 2020 Nov 2.
Astaxanthin (Asta) is widely used in the nutraceutical and food industry because of its strong antioxidant properties. However, natural Asta mainly exists in the esterified form with various fatty acid chains, making it difficult to understand the particular molecular structure of astaxanthin esters (Asta-Es) that have better antioxidant capacity. In this study, Asta-Es with different molecular structures was systematically prepared, and identified by using thin-layer chromatography (TLC), ultraviolet-visible (UV-visible), high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and proton nuclear magnetic resonance ( H-NMR). In addition, their antioxidant properties were evaluated by 2,2'-diphenylpicrylhydrazyl (DPPH) and ABTS scavenging activity.
Fourteen Asta-Es with different molecular structures were systematically synthesized. This study used a simple and efficient method for the separation and purification of astaxanthin monoester (Asta-ME) and astaxanthin diester (Asta-DE) with high purity (86%-94%) by silica gel column chromatography. 13-cis-Asta-E and 9-cis-Asta-E were firstly identified from Asta-E. The DPPH clearance rates and ABTS scavenging rates of Asta-C4:0, Asta-C8:0, Asta-C12:0, and Asta-C18:0 were relatively close, but the DPPH and ABTS scavenging rates of Asta-C18:0, Asta-C18:1, Asta-C18:2, and Asta-C22:6 increased gradually. Among all Asta-Es, Asta-C22:6/C22:6 showed the highest antioxidant capacity, with the DPPH and ABTS scavenging rates of 77.22 ± 3.29% and 51.84 ± 1.65%, respectively.
In this study, it was concluded that chemically synthesized Asta-Es contained cis-astaxanthin ester and polyunsaturated fatty acid chain increased the antioxidant activity of Asta, showing less effect of the length of fatty acid chain. These results provide useful information for the production and use of highly efficient Asta-E as functional food and pharmaceutical ingredients. © 2020 Society of Chemical Industry.
虾青素（Asta）因其具有很强的抗氧化性能而被广泛应用于营养保健品和食品工业。然而，天然虾青素主要以各种脂肪酸链的酯化形式存在，这使得难以了解具有更好抗氧化能力的虾青素酯（Asta-Es）的特殊分子结构。在本研究中，通过使用薄层层析（TLC）、紫外-可见（UV-可见）、高效液相色谱-串联质谱（HPLC-MS/MS）和质子核磁共振（H-NMR），系统地制备了具有不同分子结构的 Asta-Es，并对其进行了鉴定。此外，通过 2,2'-二苯基-1-苦基肼基（DPPH）和 ABTS 清除活性评估了它们的抗氧化性能。
系统地合成了 14 种具有不同分子结构的 Asta-Es。本研究使用简单高效的方法，通过硅胶柱层析对虾青素单酯（Asta-ME）和虾青素二酯（Asta-DE）进行分离和纯化，得到了高纯度（86%-94%）的 Asta-ME 和 Asta-DE。首次从 Asta-E 中鉴定出 13-顺式虾青素酯和 9-顺式虾青素酯。Asta-C4:0、Asta-C8:0、Asta-C12:0 和 Asta-C18:0 的 DPPH 清除率和 ABTS 清除率较为接近，但 Asta-C18:0、Asta-C18:1、Asta-C18:2 和 Asta-C22:6 的 DPPH 和 ABTS 清除率逐渐增加。在所有的 Asta-Es 中，Asta-C22:6/C22:6 具有最高的抗氧化能力，其 DPPH 和 ABTS 清除率分别为 77.22±3.29%和 51.84±1.65%。
本研究表明，化学合成的 Asta-Es 含有顺式虾青素酯和多不饱和脂肪酸链，增加了 Asta 的抗氧化活性，而脂肪酸链的长度影响较小。这些结果为高效 Asta-E 作为功能性食品和药物成分的生产和使用提供了有用的信息。 © 2020 英国化学学会。
