We have reported three phenolic compounds of the Chinese drug Tianma (Gastrodia elata Bl.). They are p-hydroxymethylphenyl-β-D-glucopyranoside (gastrodin, Ⅰ), p-hydroxybenzyl alcohol (Ⅱ) and p-hydroxybenzyl aldehyde (Ⅲ). Among them gastrodin and p-hydroxybenzyl alcohol have been synthesized and pharmacological investigation revealed that they have sedative and hypnotic effects. Clinical trials