A new 3-methoxybenzensulfonic acid 4-0-0-D-glucopyranoside (1), and ten known compounds (2-11) were isolated from the methanolic extract of the stems of Mallotus microcarpus. The cytotoxicity of the isolated compounds was evaluated by the MTT method. 3-Methoxybenzensulfonic acid 4-Ο-β-D-