The present description discloses a novel biologically active ingredient of manuka honey. Specially, the present description discloses a compound represented by the following formula. In this formula, each of R 1 , R 2 and R 3 independently represents a hydrogen atom or optionally substituted C 1-4 alkyl group, m represents an integer from 1 to 3, each of R 4-m , R 5-m and R 6-m independently represents a hydrogen atom or optionally substituted C 1-4 alkyl group, and each of R 7 , R 8 , R 9 and R 10 independently represents a hydrogen atom or optionally substituted C 1-4 alkyl group.