Peroxidase-catalyzed generation of catechin oligomers that inhibit glucosyltransferase from Streptococcus sobrinus |
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Authors: | Shigeyuki Hamada Masanori Kontani Hidekazu Hosono Hiroyuki Ono takaharu Tanaka Takashi Ooshima Tohru Mitsunaga Isao Abe |
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Institution: | Departments of Oral Microbiology and Pedodontics, Osaka University Faculty of Dentistry, Yamadaoka, Suita-Osaka 565, Japan; Suntory Research Center, Shimamotocho-Osaka 618, Japan; Department of Forest Products, Mie University Faculty of Bioresources, Tsu 514, Japan |
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Abstract: | Abstract Oolong tea extract (OTE) and the purified polymeric polyphenols from OTE have been found to inhibit glucosyltransferase (GTase) of mutans streptococci. In view of the partial fermentation characteristic of oolong tea, we describe here an in vitro model reaction system to produce partially fermented products of d-(+)-catechin or green tea extract (GTE) using horseradish peroxidase. A dimeric catechin molecule was identified as dehydro-dicatechin A by instrumental analyses. The molecular size of some oligomeric catechins was estimated by the elution profile with HPLC. These catechin oligomers markedly inhibited GTase from Streptococcus sobrinus 6715. As the degree of polymerization of catechin or GTE increased, GTase was inhibited more effectively. These results suggest that polymeric polyphenols found in OTE are synthesized by partial fermentation due to oxidases/peroxidases present in tea leaves. |
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Keywords: | Streptococcus sobrinus Glucosyltransferase α-Glucan Polyphenol Peroxidase Enzyme-catalyzed polymerization |
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