We report here the synthesis and biological properties of 3-O-alkyl analogues of (+)-catechin (5), which itself is one of the major natural polyphenols found in green tea and has several physiological activities. Starting from 5, a series of 3-O-alkyl-(+)-catechin derivatives were investigated as potent antimicrobial agents. The presence of an alkyl chain rather than acyl on 3-O- showed an increase in antimicrobial activity which may be due to stability in standard culture condition. The most promising compound is 8e, 3-O-decyl analogue, with the MIC of 0.5-2, 32-128 and 2-4 microg/mL against Gram-positive bacteria, Gram-negative bacteria and human pathogenic fungi, respectively. Regarding action mechanism, the antimicrobial activity is possibly due to the lipophilicity and disrupting ability of the analogues to the liposome membrane.
Published by Elsevier Masson SAS.