Two Pairs of Isomerically New Phenylpropanoidated Epicatechin Gallates with Neuroprotective Effects on H₂O₂-Injured SH-SY5Y Cells from Zijuan Green Tea and Their Changes in Fresh Tea Leaves Collected from Different Months and Final Product

Abstract

Zijuan tea (Camellia sinensis var. assamica), an anthocyanin-rich cultivar with purple leaves, is a valuable material for manufacturing tea with unique color and flavor. In this paper, four new phenylpropanoid substituted epicatechin gallates (pECGs), Zijuanins A−D (1−4), were isolated from Zijuan green tea by different column chromatography. Their structures were identified by extensive high resolution mass spectroscopy (HR-MS), nuclear magnetic resonance (NMR), and experimental and calculated circular dichroism (CD) spectroscopic analyses. Detection of the changes in fresh tea leaves collected from April to September and the final processed product by high performance liquid chromatography (HPLC)-HRMS suggested that production of compounds 1 and 2 may be enhanced by the processing procedure of Zijuan green tea. Additionally, 1−4 were proposed to be synthesized through interaction between the abundant secondary metabolite ECG and phenolic acids from tea leaves by two key steps of phenol−dienone tautomerism. 1 and 2 showed impressive activity in protecting SH-SY5Y cells against H 2 O 2 -induced damage at the concentration of 1.0 μM.

Discovery of Camellia sinensis catechins as SARS-CoV-2 3CL protease inhibitors through molecular docking, intra and extra cellular assays

“…Their purity was detected by HPLC ( Fig. S1-2 ) ( Cheng et al, 2018 ; Gaur et al, 2020 ; Ke et al, 2019 ; Li et al, 2018 ; Wang et al, 2021 ) including the known major tea catechins ECG, EGCG, CG and GCG to perform intracellular inhibition assay. Ebselen [(2-phenyl-1, 2-benzoisoselenazol-3(2H)-one)] was used as the positive control (IC 50 = 69.70 ± 0.28 nM).…”

“…Camellia sinensis (L.) Kuntze (Theaceae) (common name ‘tea’) is normally classified into six major types (green tea, white tea, yellow tea, oolong tea, black tea, and dark tea) according to the processing manufacture, and is popularly consumed around the world ( Ke et al 2019 ). Green tea, black tea, and oolong tea were reported to inhibit the contagious virus SARS-CoV-2 dose-dependently by in vitro cell assays ( Nishimura et al, 2021 ).…”

“…(-)-Epicatechin 3-O-caffeoate ( 1 , EC-C) can inhibit acetylcholinesterase activity ( Wang et al, 2017 ), form complex with iron and neutrophil gelatinase-associated lipocalin, and protect against β -amyloid (A β ) induced neurotoxicity in SH-SY5Y cells ( Zhang et al, 2018 ). Zijuanin C ( 2) and zijuanin D ( 3 ) are catechin esters with impressive activity in protecting SH-SY5Y cells against H 2 O 2 -induced damage ( Ke et al, 2019 ). Compounds 4-9 are ester-type flavoalkaloids isolated from white tea (Bai-Mudan) and Chinese ancient cultivated tea (Xi-Gui), which can inhibit the accumulation of advanced glycation end products and cell senescence ( Cheng et al, 2018 ; Li et al, 2018 ).…”

Enhanced Neuroprotective Effects of Epicatechin Gallate Encapsulated by Bovine Milk-Derived Exosomes against Parkinson’s Disease through Antiapoptosis and Antimitophagy

“…Ke et al also reported that ECG exhibited an impressive activity in protecting SHSY5Y cells against H 2 O 2 -induced damage. 12 However, applications were still limited because of its poor stability and intestinal permeability, which could influence the bioavailability during systemic circulation. 13,14 It is well established that the application of natural nanoparticles for compound delivery systems is an effective way to circumvent these problems.…”

The effect of storage time on tea Polyphenols, catechin compounds, total flavones and the biological activity of Ya’an Tibetan tea ( Camellia sinensis )

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Tea (Camellia sinensis) is highly consumed and enjoyed, by virtue of its taste, aroma, health benefits, and cultural value. In China, there are six types of tea, such as green tea, yellow tea, white tea, Oolong tea, black tea and dark tea (Ke et al, 2019). Consumption of Chinese dark tea began during the Ming Dynasty.

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