Phytochemical Profiling of Aloe porphyrostachys subsp. koenenii leaf epidermis by UHPLC-PDA/UV-MS/MS

Aloe porphyrostachys subsp. koenenii (Lavranos & Kerstin Koch) Lodé (syn. Aloe koenenii ) is an understudied Aloe species, and its leaf epidermis chemical components have not yet been characterized. In this work, we provide the first characterization of the leaf epidermis metabolite profile of A. porphyrostachys subsp. koenenii and compare it with Aloe vera using UPLC-PDA/UV-MS/MS. Chromatographic peaks were evaluated by UV-Vis absorption patterns and MS/MS fragmentation, enabling putative annotation of key constituents. Four compounds were annotated in A. porphyrostachys subsp. koenenii : aloin A, aloin B, aloesin, and 7-hydroxy-8- O -methylaloin. All four were also detected in A. vera , which additionally showed three further annotated constituents: homonataloside B, 7-hydroxyaloin A or B, and isoaloeresin D or aloeresin D. Thus, the two species share a core set of anthrone- and chromone-related metabolites, while A. vera exhibited a more diverse profile under the conditions evaluated. These data support chemotaxonomic affinity within the genus and highlight candidate marker compounds that may assist quality control and authentication of Aloe leaf materials, providing a chemical basis for future targeted bioactivity studies.