new hydroxybiphenyl compounds of the general formula : ## str1 ## wherein r 1 stands for a hydrogen atom or a hydroxyl group , r 2 for a hydrogen atom or a hydroxyl group , r 3 for a hydroxyl group , a group of the formula -- ch 2 -- ch ═ ch 2 or a group of the formula -- ch ═ ch -- cho , r 4 for a hydrogen atom or a group of the formula ## str2 ## and r 5 for a hydroxyl group or a group of the formula ## str3 ## these compounds are obtained by extraction of &# 34 ; tokoboku &# 34 ;, i . e . dried cortex of magnolia officinalis which belongs to the family magnoliaceae . they are useful as pharmaceuticals or intermediates therefor , in particular as anti - allergics .