Isolation of methyl syringate as a specific aflatoxin production inhibitor from the essential oil of Betula alba and aflatoxin production inhibitory activities of its related compounds

► Methyl syringate was isolated as an aflatoxin production inhibitor from Betula alba. ► It inhibited aflatoxin production of A. parasiticus and A. flavus with selectivity. ► It suppressed transcription of aflR in a dose-dependent manner. ► Among gallic acid derivatives, only methyl syringate showed selectivity. ► Its activity did not correlate to DPPH radical scavenging activity.