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Proanthocyanidins in an astringent persimmon inhibit Salmonella pathogenicity island 1 ( SPI1 ) secretion
Author(s) -
Morita Ai,
Tai Akihiro,
Ito Hideyuki,
Ganeko Natsuki,
Aizawa ShinIchi
Publication year - 2015
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.7289
Subject(s) - virulence , secretion , astringent , salmonella , microbiology and biotechnology , proanthocyanidin , diospyros kaki , biology , chemistry , pectinase , salmonella enterica , biochemistry , food science , bacteria , polyphenol , botany , enzyme , genetics , gene , taste , antioxidant
Abstract BACKGROUND Astringent compounds contained in persimmon fruits have been widely used in Japan as food preservatives and thus as anti‐bacterial and anti‐fungi reagents. However, the molecular mechanism of the anti‐microbial activity has been unclear. One of the virulence secretion systems in Salmonella enterica was used to test the anti‐microbial activity of extracts from a persimmon ( Diospyros kaki Thunb ‘Saijo’). RESULTS We found that the extract could inhibit the secretion of virulence proteins but did not affect cell growth and determined the critical concentrations of the extract to show the effect. Then, the effective fraction on the suppression of secretion of virulence proteins was purified from the crude extracts using solvent partition, absorption chromatography and gel filtration chromatography. The anti‐bacterial fraction was analysed by HCl –butanol treatment and gel permeation chromatography followed by nuclear magnetic resonance and identified as the octamers of epigallocatechin and its gallate as major components. CONCLUSION Proanthocyanidins suppress the secretion of Salmonella pathogenicity island 1 virulence proteins. © 2015 Society of Chemical Industry