Characteristics of Xanthorrhizol Rich Extract from Curcuma xanthorrhiza in the Choline Chloride-Based Natural Deep Eutectic Solvents: DNA Protective Activity and Toxicity Profiles

Imagine a green solvent that not only extracts a precious compound from turmeric but also shields your DNA from damage. That's the promise of choline chloride-based natural deep eutectic solvents.

Turmeric's rhizomes hide a treasure: xanthorrhizol, a bioactive compound with numerous health benefits. But extracting it usually requires harsh organic solvents. Now, scientists are turning to natural deep eutectic solvents (NADES) as a greener alternative.

In this study, researchers tested three choline chloride-based NADES, paired with citric, malic, or lactic acid. These solvents were more polar than ethanol, denser, and more viscous. FTIR confirmed hydrogen bonds between the components, creating a stable solvent structure.

The most promising candidate was choline chloride-malic acid (CC-MA), thanks to its lowest viscosity. It extracted similar amounts of xanthorrhizol and curcuminoids as conventional methods, according to HPLC analysis.

Both the solvents and their extracts showed antioxidant activity, scavenging DPPH radicals and reducing iron ions. They also protected pBR322 plasmid DNA from oxidative damage, though less effectively than ethanol extracts. In toxicity tests, all were benign to Staphylococcus aureus, but showed some activity against Escherichia coli—though the extracts themselves were less toxic.

This makes CC-MA a novel, low-toxicity green solvent with potential as a DNA-protective agent.

Key Points

• Choline chloride-malic acid NADES extracts xanthorrhizol effectively.
• All NADES were more polar than ethanol, with higher density and viscosity.
• NADES and extracts protected DNA and showed low toxicity to bacteria.