CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China; National Engineering Research Center for Natural Medicines, Chengdu 610041, People's Republic of China.
Food Chem. 2021 May 1;343:128392. doi: 10.1016/j.foodchem.2020.128392. Epub 2020 Oct 15.
Duckweeds have long been consumed as vegetables in several South Asian countries. In this study of the chemical constituents of duckweed Landoltia punctata, a new compound, apigenin 6-C-[β-D-apiofuranosyl-(1 → 2)]-β-D-glucopyranoside (1), and a previously LC-MS identified compound, quercetin 3-O-β-D-apiofuranoside (3), as well as three known compounds, luteolin 6-C-[β-D-apiofuranosyl-(1 → 2)]-β-D-glucopyranoside (2), apigenin 6-C-β-D-glucopyranoside (4), and luteolin 7-O-neohespirodise (5), were isolated and identified on the basis of MS and NMR spectroscopic analyses and chemical derivations. In total, 24 flavonoids were identified in L. punctata 0001 by UPLC-ESI-QTOF-MS. In DPPH and ABTS assays, 3 exhibited significant antioxidant activity with IC values of 4.03 ± 1.31 µg/mL and 14.9 ± 2.28 µg/mL, respectively. In in vivo antioxidant activity assays, 1 significantly increased the survival rate of juglone-exposed Caenorhabditis elegans by 2 to 3-fold, and by 75% following thermal damage. Compounds 1-5 exhibited moderate scavenging capacities of intracellular reactive oxygen species in C. elegans exposed to HO.
浮萍在南亚的几个国家一直被当作蔬菜食用。在对浮萍 Landoltia punctata 的化学成分研究中，分离并鉴定了一个新化合物芹菜素 6-C-[β-D-阿戊呋喃糖基-(1 → 2)]-β-D-吡喃葡萄糖苷（1）和先前通过 LC-MS 鉴定的化合物槲皮素 3-O-β-D-阿戊呋喃糖苷（3），以及 3 个已知化合物木樨草素 6-C-[β-D-阿戊呋喃糖基-(1 → 2)]-β-D-吡喃葡萄糖苷（2）、芹菜素 6-C-β-D-吡喃葡萄糖苷（4）和木樨草素 7-O-新螺旋二烯（5）。基于 MS 和 NMR 光谱分析和化学衍生化，鉴定了 1 个新化合物和 3 个已知化合物。通过 UPLC-ESI-QTOF-MS 在 L. punctata 0001 中总共鉴定出 24 种类黄酮。在 DPPH 和 ABTS 测定中，化合物 3 表现出显著的抗氧化活性，IC 值分别为 4.03 ± 1.31 µg/mL 和 14.9 ± 2.28 µg/mL。在体内抗氧化活性测定中，化合物 1 使受胡桃醌暴露的秀丽隐杆线虫的存活率提高了 2 至 3 倍，在热损伤后提高了 75%。化合物 1-5 对暴露于 HO 的秀丽隐杆线虫细胞内活性氧具有中等的清除能力。
