Heteropterys angustifolia - A preliminary TLC study While Heteropterys angustifolia is poorly characterised, CNS (anxiolytic, antidepressant, improving learning and memory) and antioxidant effects and the protective activities of reproductive male organs are the most important biological activities reported for species of Heteropterys Flavonoids are the chemicals most conspicuous, followed by potentially toxic aliphatic nitro compounds (also potentially antibacterial and anti-viral etc) and hydroxycinnamic acids identified in Heteropterys [1]. Due to the morphological similarity to, and botanical proximity to Banisteriopsis spp., it was selected as a potentially interesting plant to study. The known phytochemistry and pharmacology of the family Malpighiaceae has been detailed here [2]. 1 H. angustifolia was found to contain hiptagin (1, 2, 4, 6-tetra-3-nitropropanoyl-β-D- glucopyranoside). The fresh roots gave a very strong positive test for nitro compounds while the fresh aerial parts showed a weakly positive. In contrast, the heat-dried samples exhibited a weak or negative test to these potentially toxic constituents They may have potential as a source of new adaptogenic substances. Another similar plant, Heteropterys aphrodisiaca , endemic to the Brazilian scrubland regions, is traditionally used in folk medicine as an aphrodisiac, a stimulant and in the treatment of nervous weakness. Stem bark was macerated in warm 95% EtOH and concentrated to a small sample. Initial TLC elution with 95% ethanol failed to give good resolution of the constituents but 1:1 acetone:white spirits gave good separation of the constituents. Visualisation under UV showed major constituents at Rf = 0.83 (greenish yellow fluorescence), 0.73 (red fluorescence) and a trace constituent at 0.65. A strong residual fluorescent constituent remained at Rf = 0 (yellow fluorescence). In previous TLCs, some beta-carboline containing plants had a similar residual constituent that failed to elute and displayed strong fluorescence. Unfortunately, the UV fluorescent constituents were poorly visible with the available camera. 2 The presence of a diverse range of strongly fluorescent constituents in the stem bark is intriguing. While no reference samples to compare to Banisteriopsis or relevant beta- carboline containing plant materials were available, it may be worth considering analysing this plant further for the presence of such phytoconstituents. [1] https://scialert.net/fulltext/?doi=ijp.2015.523.531 [2] https://doi.org/10.21608/ejchem.2022.119510.5372 3