Hatano Tsutomu, Kusuda Miwako, Hori Mami, Shiota Sumiko, Tsuchiya Tomofusa, Yoshida Takashi
Department of Pharmacognosy, Faculty of Pharmaceutical Sciences, Okayama University, Tsushima, Okayama, Japan.
Planta Med. 2003 Nov;69(11):984-9. doi: 10.1055/s-2003-45142.
When (-)-epigallocatechin gallate (EGCG), the main constituent of tea polyphenols, was kept in a neutral buffer, it decomposed rapidly to give theasinensin A as the major product. Theasinensin A suppressed the oxacillin resistance of methicillin-resistant Staphylococcus aureus (MRSA). In the presence of theasinensin A (3.5 x 10(-5) M), the minimum inhibitory concentrations (MICs) of oxacillin decreased from 256 or 64 microg/mL to 4 microg/mL for the MRSA strains used. The presence of this compound (3.5 x 10(-5) M) also decreased the MIC of other beta-lactam (penicillin G, from 32 microg/mL to 0.125-0.5 microg/mL; ampicillin, from 16-32 microg/mL to 0.5-1 microg/mL) and aminoglycoside (streptomycin, from 4 - 16 microg/mL to 0.125-4 microg/mL) antibiotics for the MRSA strains.
当茶多酚的主要成分（-）-表没食子儿茶素没食子酸酯（EGCG）置于中性缓冲液中时，它会迅速分解，以茶黄素A作为主要产物。茶黄素A可抑制耐甲氧西林金黄色葡萄球菌（MRSA）对苯唑西林的耐药性。在茶黄素A（3.5×10⁻⁵ M）存在的情况下，所用MRSA菌株对苯唑西林的最低抑菌浓度（MIC）从256或64μg/mL降至4μg/mL。该化合物（3.5×10⁻⁵ M）的存在还降低了其他β-内酰胺类（青霉素G，从32μg/mL降至0.125 - 0.5μg/mL；氨苄西林，从16 - 32μg/mL降至0.5 - 1μg/mL）和氨基糖苷类（链霉素，从4 - 16μg/mL降至0.125 - 4μg/mL）抗生素对MRSA菌株的MIC。
