Chemical Profiling by UHPLC-MS/MS and In Vitro Antioxidant, Antimicrobial, and Cytotoxic Properties of Lepidoceras peruvianum Kuijt Leaves and Fruits.

RATIONALE: Lepidoceras peruvianum Kuijt is an understudied hemiparasitic species endemic to the Peruvian Andes that lacks comprehensive phytochemical characterization. Investigating its metabolome is important for understanding its chemotaxonomic relevance and potential as a source of bioactive compounds.

METHODS

Leaves and fruits of L. peruvianum were subjected to untargeted metabolomic profiling using high-resolution UHPLC-ESI-Orbitrap-MS/MS in positive and negative ionization modes. Metabolites were annotated based on accurate mass measurements, isotopic patterns, collision-induced dissociation (CID) fragmentation data, and spectral matching with the Global Natural Products Social Molecular Networking (GNPS), METLIN, and MassBank databases. Structural elucidation employed diagnostic fragmentation pathways, including retro-Diels-Alder (RDA), heterocyclic ring fission (HRF), quinone methide (QM), and benzofuran-forming (BFF) cleavages. Antioxidant activity was evaluated using DPPH●, ABTS●+, and FRAP assays, while antimicrobial activity and toxicity were assessed through antibacterial testing and the Artemia salina lethality assay.

RESULTS

Leaves contained 34 metabolites, mainly flavan-3-ols, proanthocyanidins, flavonols, lignans, and isoquinoline alkaloids, whereas fruits were characterized by anthocyanins, organic acids, and polar lipids. Total phenolic content was higher in leaves (292.4 mg GAE/g) than in fruits (216.8 mg GAE/g), corresponding to stronger antioxidant activity. Leaves extracts exhibited greater antibacterial activity against Staphylococcus aureus, while fruit extracts showed stronger effects against Gram-negative bacteria. LC50 values in the A. salina assay were 181.8 μg/mL for leaves and 475.9 μg/mL for fruits.

CONCLUSIONS

This study provides the first comprehensive metabolomic characterization of L. peruvianum, revealing organ-specific chemical diversity and notable bioactive properties. The findings demonstrate the utility of HRMS/MS fragmentation analysis for metabolite annotation and identify this endemic species as a promising source of bioactive natural products.