<jats:p> The bark of Zanthoxylum dominianum Merr. & Perry gave suberosin and canthin-6-one in about the same high yields that were previously reported from Z. suberosum C. T. White. The result confirms the previous work and supports the recently expressed view that the names are synonymous. Minor constituents isolated were palmitic acid, ?sitosterol?, β- amyrin, isopimpinellin, 7-methoxycoumarin-6-aldehyde, and two new coumarins, ?suberenol? and ?cyclobisuberodiene?. The structure of suberenol has been established as (X), and evidence in favour of (XXI) as the structure of cyclobisuberodiene obtained.