GREEN EXTRACTION OF Avicennia marina LEAVES BY NATURAL DEEP EUTECTIC SOLVENTS: PHYTOCHEMICAL PROFILE, ANTIOXIDANT ACTIVITY, MOLECULAR DOCKING AND ADMET ANALYSIS

What if the secret to a powerful natural antibiotic was hiding in mangrove leaves, unlocked by a solvent as green as the plant itself? A new study reveals just that.

Mangroves are tough survivors, but their leaves may hold more than just salt tolerance. Researchers have turned to Natural Deep Eutectic Solvents (NADES)—eco-friendly alternatives to harsh chemicals—to extract bioactive compounds from young and old leaves of Avicennia marina. Using a mix of citric acid and glucose at different molar ratios, they tested the extracts against two notorious bacteria: Staphylococcus aureus and Escherichia coli.

The best results came from a 4:1 ratio of citric acid to glucose. Old leaves produced inhibition zones of 27.47 mm against S. aureus and 37.73 mm against E. coli, while young leaves showed 28.69 mm and 30.99 mm, respectively. These are impressive numbers in the world of antibacterial testing.

To understand what made these extracts so potent, the team used liquid chromatography-mass spectrometry and identified six phytochemical compounds. Then, in silico docking against the enzyme peptide deformylase (ID 6JFQ) revealed that diosmetin 7-O-β-D-glucuronide had the strongest binding affinity at -9.4 kcal/mol, suggesting it could be a key player in the antibacterial action.

While the findings are promising, the researchers note that purification is still needed to isolate pure compounds from the crude extracts. This green approach could pave the way for sustainable antibiotic development.

Key Points

• NADES with citric acid and glucose (4:1) gave best antibacterial activity.
• Old leaves inhibited S. aureus (27.47 mm) and E. coli (37.73 mm).
• Diosmetin 7-O-β-D-glucuronide showed strongest docking affinity (-9.4 kcal/mol).