Five Solandra species have been investigated for their alkaloid content; they constitute a uniform phytochemical group. Alkaloids isolated or detected are atropine, hyoscyamine, noratropine (principal alkaloids), littorine, hyoscine, norhyoscine in one instance, tigloidine, 3α-tigloyloxytropane, 3α-acetoxytropane, valtropine, tropine, ψ-tropine, cuscohygrine. © 1971.