Zanthoxylum williamsii (Rutaceae) was found to contain (+)-asaranin, (+)-sesamin, esculetin dimethyl ether, nitidine, chelerythrine, magnoflorine, laurifoline, skimmianine and edulinine. The quaternary alkaloid fraction of Z. monophyllum contained berberine, magnoflorine, chelerythrine and a 1,2,9,10-substituted dihydroxydimethoxy-N,N-dimethylaporphinium salt. Leaves of Z. fagara were found to contain synephrine. Leaves of each species were examined for the presence of bishordeninyl terpene alkaloids, but none was found. Some chemotaxonomic relationships among Zanthoxylum species are discussed. © 1980.