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HPLC analysis of naturally occurring methylated catechins, 3' '- and 4' '-methyl-epigallocatechin gallate, in various fresh tea leaves and commercial teas and their potent inhibitory effects on inducible nitric oxide synthase in macrophages.
J Agric Food Chem. 2005 Sep 07; 53(18):7035-42.JA

Abstract

(-)-Epigallocatechin-3-gallate (EGCG), a major polyphenol of green tea, undergoes substantial biotransformation to species that includes the methylated compounds. Recent studies have demonstrated that the methylated EGCG has many biological activities. In this study, we have investigated the composition of the three O-methylated EGCG derivatives, (-)-epigallocatechin-3-O-(3-O-methyl)gallate (3' '-Me-EGCG), (-)-epigallocatechin-3-O-(4-O-methyl)gallate (4' '-Me-EGCG) and (-)-4'-methyl epigallocatechin-3-O-(4-O-methyl)gallate (4',4' '-di-Me-EGCG) in tea leaves which were picked from various species and at various seasons, ages of leaves, locations, and fermentation levels. Higher levels of 3' '-Me-EGCG and 4' '-Me-EGCG were detected in Chinshin-Kanzai (a species of Camellia sinensis) cultivated in the mountain area of Sansia, Taipei County, Taiwan. Also, these O-methylated EGCG levels were found to be higher in autumn and winter than in spring and summer. The young leaves were found to be richer in the O-methylated compounds than old leaves and the amount of O-methylated EGCG was higher in unfermented longjin green tea than in semifermented oolong tea. However, the fermented black tea and puerh tea did not contain these compounds. 4',4' '-diMe-EGCG could not be detected in either fresh tea leaves or commercial tea leaves. We also found that 3' '-Me-EGCG has a higher inhibitory effect on the nitric oxide generation and inducible nitric oxide synthase (iNOS) expression as compared with EGCG, while 4' '-Me-EGCG and 4',4' '-di-Me-EGCG were less effective.

Authors+Show Affiliations

Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Number 1, Section 1, Taipei, Taiwan.No affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

16131108

Citation

Chiu, Feng-Lan, and Jen-Kun Lin. "HPLC Analysis of Naturally Occurring Methylated Catechins, 3' '- and 4' '-methyl-epigallocatechin Gallate, in Various Fresh Tea Leaves and Commercial Teas and Their Potent Inhibitory Effects On Inducible Nitric Oxide Synthase in Macrophages." Journal of Agricultural and Food Chemistry, vol. 53, no. 18, 2005, pp. 7035-42.
Chiu FL, Lin JK. HPLC analysis of naturally occurring methylated catechins, 3' '- and 4' '-methyl-epigallocatechin gallate, in various fresh tea leaves and commercial teas and their potent inhibitory effects on inducible nitric oxide synthase in macrophages. J Agric Food Chem. 2005;53(18):7035-42.
Chiu, F. L., & Lin, J. K. (2005). HPLC analysis of naturally occurring methylated catechins, 3' '- and 4' '-methyl-epigallocatechin gallate, in various fresh tea leaves and commercial teas and their potent inhibitory effects on inducible nitric oxide synthase in macrophages. Journal of Agricultural and Food Chemistry, 53(18), 7035-42.
Chiu FL, Lin JK. HPLC Analysis of Naturally Occurring Methylated Catechins, 3' '- and 4' '-methyl-epigallocatechin Gallate, in Various Fresh Tea Leaves and Commercial Teas and Their Potent Inhibitory Effects On Inducible Nitric Oxide Synthase in Macrophages. J Agric Food Chem. 2005 Sep 7;53(18):7035-42. PubMed PMID: 16131108.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - HPLC analysis of naturally occurring methylated catechins, 3' '- and 4' '-methyl-epigallocatechin gallate, in various fresh tea leaves and commercial teas and their potent inhibitory effects on inducible nitric oxide synthase in macrophages. AU - Chiu,Feng-Lan, AU - Lin,Jen-Kun, PY - 2005/9/1/pubmed PY - 2005/10/12/medline PY - 2005/9/1/entrez SP - 7035 EP - 42 JF - Journal of agricultural and food chemistry JO - J. Agric. Food Chem. VL - 53 IS - 18 N2 - (-)-Epigallocatechin-3-gallate (EGCG), a major polyphenol of green tea, undergoes substantial biotransformation to species that includes the methylated compounds. Recent studies have demonstrated that the methylated EGCG has many biological activities. In this study, we have investigated the composition of the three O-methylated EGCG derivatives, (-)-epigallocatechin-3-O-(3-O-methyl)gallate (3' '-Me-EGCG), (-)-epigallocatechin-3-O-(4-O-methyl)gallate (4' '-Me-EGCG) and (-)-4'-methyl epigallocatechin-3-O-(4-O-methyl)gallate (4',4' '-di-Me-EGCG) in tea leaves which were picked from various species and at various seasons, ages of leaves, locations, and fermentation levels. Higher levels of 3' '-Me-EGCG and 4' '-Me-EGCG were detected in Chinshin-Kanzai (a species of Camellia sinensis) cultivated in the mountain area of Sansia, Taipei County, Taiwan. Also, these O-methylated EGCG levels were found to be higher in autumn and winter than in spring and summer. The young leaves were found to be richer in the O-methylated compounds than old leaves and the amount of O-methylated EGCG was higher in unfermented longjin green tea than in semifermented oolong tea. However, the fermented black tea and puerh tea did not contain these compounds. 4',4' '-diMe-EGCG could not be detected in either fresh tea leaves or commercial tea leaves. We also found that 3' '-Me-EGCG has a higher inhibitory effect on the nitric oxide generation and inducible nitric oxide synthase (iNOS) expression as compared with EGCG, while 4' '-Me-EGCG and 4',4' '-di-Me-EGCG were less effective. SN - 0021-8561 UR - https://www.unboundmedicine.com/medline/citation/16131108/HPLC_analysis_of_naturally_occurring_methylated_catechins_3'_'__and_4'_'_methyl_epigallocatechin_gallate_in_various_fresh_tea_leaves_and_commercial_teas_and_their_potent_inhibitory_effects_on_inducible_nitric_oxide_synthase_in_macrophages_ L2 - https://dx.doi.org/10.1021/jf0507442 DB - PRIME DP - Unbound Medicine ER -