Flavonoids and antioxidant activity of rare and endangered fern: Isoetes sinensis

• Published in: PloS one Vol. 15; no. 5; p. e0232185
• Main Authors: Wang, Xin, Ding, Guohua, Liu, Baodong, Wang, Quanxi
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 12.05.2020; Public Library of Science (PLoS)
• Subjects: Analysis; Antioxidants; Antioxidants (Nutrients); Antioxidants - analysis; Antioxidants - pharmacology; Biological activity; Biology and Life Sciences; Chemical properties; Endangered plants; Endangered Species; Experiments; Ferns; Ferns - chemistry; Flavones; Flavonoids; Flavonoids - analysis; Flavonoids - pharmacology; Flavonols; Free radicals; Herbal medicine; Isoetes; Isoflavones; Kaempferol; Life sciences; Mass spectrometry; Mass spectroscopy; Medicinal plants; Phylogeny; Physical Sciences; Plant protection; Procyanidins; Protected plants; Quercetin; Recovery (Medical); Research and Analysis Methods; Scavenging; Spectroscopy; Ultrastructure; China; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0232185

Isoetes sinensis Palmer is a critically endangered, first-class protected plant in China. Until now, researchers have primarily focused on the ultrastructure, phylogeny, and transcriptomes of the plant. However, flavonoid profiles and bioactivity of I. sinensis have not been extensively investigated. To develop the endangered I. sinensis for edible and medicinal purposes, flavonoid content, chemical constitution, and antioxidant activities were investigated in this study. Results revealed the following. 1) The total flavonoid content was determined as 10.74 ± 0.25 mg/g., 2) Antioxidant activities were stronger than most ferns, especially ABTS free radical scavenging activities. 3) Four flavones, containing apigenin, apigenin-7-glucuronide, acacetin-7-O-glcopyranoside, and homoplantageninisoetin; four flavonols, namely, isoetin, kaempferol-3-O-glucoside, quercetin-3-O-[6"-O-(3-hydroxy-3-methylglutaryl)-β-D-glucopyranoside], and limocitrin-Neo; one prodelphinidin (procyanidins;) and one nothofagin (dihydrochalcone) were tentatively identified in the mass spectrometry-DAD (254nm) chromatograms. This study was the first to report on flavonoid content and antioxidant activities of I. sinensis. Stronger antioxidant activity and flavonoid content suggests that the endangered I. sinensis is an important and potentially edible and medicinal plant.