Anisodamine is a natural tropane alkaloid shown to be a weak antagonist of α1-adrenoceptors, blocking WB-4101 and clonidine binding in brain membrane preparations with pKi values of 2.63 and 1.61, respectively.[1] Anisodamine also has antioxidant effects that may protect against free radical-induced cellular damage.[2] Anisodamine is predominantly found in the roots of A. tanguticus, which is used in traditional Chinese medicine for topical applications.[3]

Reference:
[1]. Varma, D.R., and Yue, T.L. Adrenoceptor blocking properties of atropine-like agents anisodamine and anisodine on brain and cardiovascular tissues of rats. British Journal of Pharmacology 87(3), 587-594 (1986).
[2]. Poupko, J.M., Baskin, S.I., and Moore, E. The pharmacological properties of anisodamine. Journal of Applied Toxicology 27(2), 116-121 (2007).
[3]. Ma, L., Gu, R., Tang, L., et al. Important poisonous plants in tβ ethnomedicine. Toxins (Basel) 7(1), 138-155 (2015).