If the extraction procedure does not involve HBr, then I would doubt it is the hydrobromide because:
- hydrobromide salts don't dissolve well in acetone;
- hydrobromide salts are rare in nature.
According to the work by Bracci et al. [1], the major component of MeOH extraction of Brugmansia is atropine.
Śramska et al. [2] used ethyl acetate extraction and isolated scopolamine and atropine.
No mention of hydrobromide salts in either.
References
- Bracci, A.; Daza-Losada, M.; Aguilar, M.; De Feo, V.; Miñarro, J.; Rodríguez-Arias, M. A Methanol Extract of Brugmansia Arborea Affects the Reinforcing and Motor Effects of Morphine and Cocaine in Mice. Evidence-Based Complementary and Alternative Medicine 2013, 2013, 1–7. https://doi.org/10/f96zpc.
- Śramska, P.; Maciejka, A.; Topolewska, A.; Stepnowski, P.; Haliński, Ł. P. Isolation of Atropine and Scopolamine from Plant Material Using Liquid-Liquid Extraction and EXtrelut® Columns. J. Chromatogr. B Analyt. Technol. Biomed. Life Sci. 2017, 1043, 202–208. https://doi.org/10/f9wvv8.