To illustrate the formation mechanism of theasinensins (TSs) and the competitive formation between TSs and theaflavins (TFs), catechins((EGCG, EGC, EC and ECG) were oxidized to form TSs monomers or TFs monomers by enzymatic oxidation and the experiments were performed by liquid fermentation under different pH values. The results showed that the TSs monomers were synthesized and accumulated continuously under acidic conditions, while the peaks of TSs monomers appeared in a short time but showed poor stability under neutral or alkaline conditions. Due to the magnitudes of the oxidation reduction potential (ORP) are variable for catechins, the enzymatic oxidative rates of catechins are different under different pH conditions. For the reason that there was a competition between the formation of TSs and TFs: the content of TSs monomers transformed by EGCG and EGC was higher than TFs monomers under the neutral condition or pH=6, however, conversely under the condition pH=5.
XU Bin
,
JIANG Heyuan
,
ZHANG Jianyong
,
YANG Liuyan
,
LIU Qianlu
. Formation Mechanism of TSs and Competitive Formation Between TSs and TFs under Various pH[J]. Journal of Tea Science, 2015
, 35(3)
: 281
-289
.
DOI: 10.13305/j.cnki.jts.2015.03.011
[1] Roberts E A H, Cartwright R A, Oldschool M. The phenolic substance of manufactured tea.Ⅰ[J]. J sci Food Agric, 1957, 8(2): 72-80.
[2] Roberts E A H. The phenolic substance of manufactured tea Ⅱ[J]. J sci Food Agric, 1958, 9(4): 212-216.
[3] Nonaka G, kawahara O, Nishioka I. Tannins and related compounds XV A new class of dimeric flavan-3-ol gallates, theasinensin A and theasinensin B, and proanthocyanidin gallates from green tea leaf[J]. Chem Pharm bull, 1983, 31(11): 3906-3914.
[4] Shii T, Tanaka T, Watarumi S, et al. Polyphenol composition of a functional fermented tea obtained by Tea-Rolling processing of green tea and loquat leaves[J]. J Agric Food Chem, 2011, 59(13): 7253-7260.
[5] Hatano T, Kusuda1 M, Hori M, et al. Theasinensin A, a tea polyphenol formed from (-)-epigallocatechin gallate, suppresses antibiotic resistance of methicillin-resistant staphylococcus aureus[J]. Planta Med, 2003, 69(11): 984-989.
[6] Hou D X, Masuzaki S, Tanigawa S, et al. Oolong Tea Theasinensins Attenuate Cyclooxygenase-2 Expression in Lipopolysaccharide (LPS)-Activated Mouse Macrophages: Structure-Activity Relationship and Molecular Mechanisms[J]. J Agric Food Chem, 2010, 58(24): 12735-12743.
[7] Isaacs C E, Xu W M, Merz G, et al. Digallate dimers of (-)-epigallocatechin gallate Inactivate herpes simplex virus[J]. Antimicrob Agents Chemother, 2011, 55(12): 5646-5653.
[8] Hashimoto F, Ono M, Masuoka C, et al. Evaluation of the anti-oxidative effect (in vitro) of tea polyphenols [J]. Biosci biotechnol biochem, 2003, 67(2): 396-401.
[9] Pan M H, Liang Y C, Lin-Shiau S Y, et al. Induction of Apoptosis by the Oolong Tea Polyphenol Theasinensin A through Cytochrome c Release and Activation of Caspase-9 and Caspase-3 in Human U937 Cells[J]. J Agric Food Chem, 2000, 48(12): 6337-6346.
[10] M iyata Y, Tanaka T, Tamaya K, et al. Cholesterol-Lowering Effect of Black Tea Polyphenols, Theaflavins, Theasinensin A and Thearubigins [J]. Food Science and Technology Research, 2011, 17(6): 585-588.
[11] Toshima A, Matsui T, Noguchi M, et al. Identification of α-glucosidase inhibitors from a new fermented tea obtained by tea-rolling processing of loquat (Eriobotrya japonica) and green tea leaves[J]. J Sci Food Agric, 2010, 90(9): 1545-1550.
[12] Hashimoto F, Nonaka G, nishioka I. Tannins and related compounds LXIX. Isolation and structure elucidation of B, B’-linked bisflavanoids, theasinensin D-G and oolongtheanin from oolong tea[J]. Chem Pharm Bull, 1988, 36(5): 1676-1684.
[13] Tanaka T, Watarumi S, Matsuo Y, et al. Production of theasinensins A and D, epigallocatechin gallate dimers of black tea, by oxidation-reduction dismutation of dehydrotheasinensin A[J]. Tetrahedron, 2003, 59(40): 7939-7947.
[14] Hashimoto F, Nonaka G, Nishioka I.Tannins and related compounds, CXIV. Structures of novel fermentation products, theogallinin, theaflavonin and desgalloyl theaflavonin from black tea, and changes of tea leaf polyphenols during fermentation[J]. Chem Pharm Bull, 1992, 40(6): 1383-1389.
[15] 薛金金, 江和源, 龙丹, 等. HPLC法同时测定茶叶中聚酯型儿茶素和茶黄素[J]. 中国食品学报, 2014, 14(5): 237-243.
[16] Tanaka T, Matsuo Y, Kouno I.A novel black tea pigment and two new oxidation products of epigallocatechin-3-O-gallate[J]. J Agric Food Chem, 2005, 53(19): 7571-7578.
[17] 徐斌, 薛金金, 江和源, 等. 茶叶中聚酯型儿茶素的研究进展[J]. 茶叶科学, 2014, 34(4): 315-323.
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