From the neutral fraction of a methanolic extract of the roots of Haplophyllum obtusifolium Ledeb. (family Rutaceae) have been isolated the lignan diphyllin, the alkaloids skimmianine and γ-fagarine, and a new coumarin with mp 179-180°C the structure of which has been established as 3-(α,α-dimethylallyl)-7-methoxy-8(3-methylbuta-1,3-diethyl)coumarin. © 1988 Plenum Publishing Corporation.