Exploring bioactive compounds from rosemary waste for structural insights and food packaging innovation

This study presents a sustainable and innovative approach to waste valorisation by isolating and characterising bioactive norursane-type triterpenoids from the solid waste of Rosmarinus tournefortii de Noé. A cost-effective, solvent-based recrystallisation method was developed as an eco-friendly alternative to traditional chromatography techniques, which are often expensive and resource-intensive. Individual triterpenoids were structurally characterised using ATR-FTIR, CHNSO elemental analysis, 1D and 2D NMR, UHPLC-MS/MS, and stereochemical analysis with Schrödinger's Maestro software. Their bioactivities were extensively evaluated. Notably, compound 3' exhibited enhanced antimicrobial activity in its amorphous form compared to its crystalline counterpart, highlighting the influence of physical structure on bioactivity. In contrast, the crystalline form of the same compound showed enhanced tyrosinase inhibitory activity, indicating that different physical states may favour different biological functions. Furthermore, the isolated compounds also demonstrated significant skin depigmentation properties through tyrosinase inhibition, with compound 2 showing the most potent effect. Molecular docking supported this activity, revealing a higher binding affinity than kojic acid. Compound 1 showed promising antidiabetic potential by outperforming acarbose in docking studies with α -amylase and α -glucosidase. These findings highlight the potential of norursane triterpenoids as multifunctional bioactive agents. It is hypothesised that such compounds, derived from agro-industrial waste, hold significant promise for use in advanced food materials. The study proposes their integration into porous food packaging systems for controlled release and targeted bioactivity, with attention to their interactions within food matrices. • Cost-effective recrystallization purifies novel nor-ursane from rosemary solid waste. • ATR-FTIR, CHNSO, 2D NMR and UHPLC-MS/MS enabled compound characterization. • Strong antimicrobial activity and effective tyrosinase inhibition were demonstrated. • Docking studies reveal exceptional binding to α-amylase/glucosidase and tyrosinase. • Nor-ursane triterpenoids support eco-friendly and sustainable food packaging.