Chemical Constituents of Cyperus esculentus Leaves and the Protective Effect against Agricultural Fungicide-Induced Hepatotoxicity.

Cyperus esculentus is cultivated as a crop plant due to its edible and oily tubers (tiger nut). However, little is known about the phytochemicals and bioeffects of the leaves. This study was conducted to identify and quantify the chemical constituents of C. esculentus leaves and evaluate their bioactivities. By liquid chromatography-mass spectrometry, 30 compounds including flavan-3-ols, caffeic acid derivatives, and flavones, were identified from the leaves. The quantitative analysis revealed that gallocatechin (8), procyanidin B1 (15), catechin (16), chlorogenic acid (19), orientin (30), and luteolin 7-O-glucuronide (31) are the major chemical constituents of C. esculentus leaves. The contents of these six chemical constituents in the leaves collected in September in Hohhot, China, reached to 1460.85±7.66, 10178.77±302.65, 1048.35±17.37, 1722.15±26.13, 5318.62±277.16, and 1526.54±11.95 μg, respectively, in one gram of the dried leaves. The leaf extract (CELE) showed strong antioxidant activity in vitro, with compounds 8, 15, and 19 contributing the most. CELE showed significant protection against the agricultural fungicide tebuconazole-induced developmental toxicity and hepatotoxicity in zebrafish.