3-Butylidenephthalide is an isobenzofuranone. 3-Butylidenephthalide has antihyperglycemic effect is due to inhibition of α-glucosidase at the intestinal level, inhibited the activity of yeast-α-glucosidase (IC(50) 2.35 mM) in a noncompetitive fashion with a K(i) of 4.86 mM. It can induce a dose-dependent antinociceptive action in the hot-plate assay, it is also effective for controlling the pain provoked by chemical irritation at the doses of 10 and 31.6 mg/kg. 3-Butylidenephthalide is a phthalic anhydride derivative identified from Ligusticum chuanxiong Hort, with insecticidal activity (LC50 value of 1.56 mg/g for Spodoptera litura larvae).