Extraction Optimization of Phenolic Compounds from Rimpang Lempuyang Gajah (Z. Zerumbet): Green Solvent (NADES-UAE) (Ultrasound-Assisted Extraction) and MAE (Microwave Assisted Extraction)

What if the key to unlocking nature's medicine cabinet lies in a simple mix of sugar and salt? For Indonesia's Lempuyang Gajah, this green chemistry twist is proving to be a game-changer.

Indonesia's Lempuyang Gajah (Zingiber zerumbet) has long been a medicinal staple, yet its full potential remains underexplored. Traditional extraction methods, like maceration, demand days of soaking in organic solvents—a slow, wasteful process. Enter Natural Deep Eutectic Solvents (NADES), a 21st-century green alternative that mimics nature's own chemistry. When paired with ultrasound (UAE) and microwave assistance (MAE), these solvents accelerate extraction while slashing environmental impact.

In this study, scientists synthesized NADES using choline chloride as the hydrogen bond acceptor, combined with glucose, lactic acid, or ethylene glycol at 1:1 and 1:2 ratios. They tested maceration, UAE, and combined UAE-MAE, varying extraction times from 2 to 6 hours. The results were striking: the best flavonoid yield (697.24 mg QE/g extract) came from a choline chloride:glycerol 1:2 mix via UAE-MAE, while the highest phenolic content (2491.88 mg GA/g extract) used a 1:1 ratio of the same components, also with UAE-MAE.

FTIR analysis confirmed hydrogen bonding in the NADES, and HPLC-DAD validated the phenolic and flavonoid profiles. This green approach not only boosts efficiency but also aligns with sustainable chemistry—proving that sometimes, the simplest solutions are the most powerful.

Key Points

• NADES with choline chloride + glycerol boosts phenolic extraction.
• UAE-MAE method yields highest TFC and TPC values.
• Green solvent cuts extraction time from days to hours.