Investigation of Secondary Metabolites and Their Bioactive Potential in Various Iris Species and Cultivars Grown under Different Cultivation Conditions

This study analyzed the bioactive secondary metabolites
in leaves
and roots with rhizomes of various Iris species and cultivars (subgenus Iris and Limniris) grown under different
conditions. Plants were cultivated in aeroponics and hydroponics and
treated with a feather hydrolysate as an alternative nutrient source
or arbuscular mycorrhizal fungi (AMF) to promote metabolite production.
Phytochemical profiling was performed by using UHPLC-HRMS/MS, aided
by in silico fragmentation for compound identification. Chemometric
analyses revealed differences in the metabolic profiles between plant
parts, including upregulation of phenolic acids, steroids, and C-glycosyl xanthones in the leaves and of stilbenes, triterpenoids,
and benzophenones in the roots with rhizomes. Variations between the
subgenera Iris and Limniris revealed possible chemotaxonomic markers, while cultivars of the
same species showed a close similarity. Hydroponics resulted in upregulation
of 232 metabolites, including flavone and isoflavonoid glycosides,
compared to 42 upregulated metabolites in aeroponics, like xanthones
and benzofurans. Neither feather hydrolysate nor AMF significantly
altered the profile of detected metabolites. The correlation of the
phytochemical profiles with biochemical assays of the Iris extracts indicated metabolites with cytotoxic,
antimicrobial, and anti-inflammatory potential, including both known
bioactive compounds (e.g., iridin, phalerin, or p-coumaric acid) and compounds with no published bioactivity data
(e.g., irisjaponin A).