Aqueous hydrotrope-based green extraction of alkaloids: insights into mechanism and experimentation with Coptis chinensis

What if the key to unlocking nature's chemical treasures lies not in harsh solvents, but in a gentle, green whisper? A new study on the Chilean lichen Sticta caulescens reveals just that.

In the quest for sustainable chemistry, researchers compared two extraction methods on the Chilean lichen Sticta caulescens: traditional methanol maceration and microwave-assisted extraction (MAE) using ethyl lactate, a green solvent. The results were striking: maceration yielded a slightly higher extract percentage (6.3% vs 5.0%), but MAE extracted an almost identical spectrum of metabolites—33 compounds versus 32—including one unique compound only seen under MAE conditions. This highlights MAE's efficiency and selectivity, offering a greener path without sacrificing chemical richness.

Beyond extraction, the study delved into chemoinformatics and chemotaxonomy, analyzing secondary metabolites across 12 Sticta species. Using computational tools like Morgan fingerprints and hierarchical clustering, they found S. caulescens to be one of the most chemically diverse species, closely related to S. cordillerana, and part of a major lineage characterized by high scaffold richness and shared biosynthetic pathways for aromatics and depsidones.

This work underscores the power of green chemistry to explore biodiversity while preserving it. By choosing ethyl lactate over methanol, we not only reduce environmental impact but also uncover hidden chemical gems—proving that sustainability and discovery can go hand in hand.

Key Points

• MAE with ethyl lactate matches methanol's metabolite yield.
• S. caulescens is chemically diverse, related to S. cordillerana.
• Green extraction reveals unique compound under MAE.