This study investigates the secondary metabolites and antibacterial activity of boiling water extract from Sonneratia alba leaves using in vitro and in silico approaches. The use of boiling water as an extraction solvent ensures safety for consumer applications in functional foods. Six extraction times (5, 10, 15, 20, 25, and 30 min) were evaluated. The 30-minute extraction yielded the highest flavonoid (20.22 ± 1.41 mg quercetin equivalent/g) and tannin (2.63 ± 0.34 mg tannic acid equivalent/g) contents. This extract exhibited strong antibacterial activity against Escherichia coli, Staphylococcus aureus, Streptococcus mutans, and Pseudomonas aeruginosa, with the highest activity against S. mutans (inhibition zone: 18.17 ± 0.29 mm), comparable to ciprofloxacin (21.17 ± 0.29 mm). Gas chromatography-mass spectrometry identified 65 compounds. Molecular docking analysis revealed three compounds with favorable binding to Glucan-Binding Protein C (GbpC) of S. mutans: 2-acetonyl-9-[3-deoxy-β-D-ribofuranosyl]hypoxanthine, paromomycin, and melezitose. Melezitose showed optimal binding conformation with key active site residues (Glu A:360 and Asn A:349). These findings demonstrate the potential of S. alba leaf extract as a natural antibacterial agent for functional food development, though further in vivo validation is required.

The potential of seaweed as a source of bioactive compounds including antioxidants made it a versatile form of ingredient that can be incorporated directly or indirectly in the preparation of foods and beverages. Antioxidant constituents are important in managing and regulating oxidative stress and protecting the human body from severe adverse effects due to the excess release of free radicals or reactive oxygen species that promote the onset of chronic diseases. This study aimed to make a functional beverage containing 20 – 30% Caulerpa racemosa (seaweed), and identify phytocompounds using GC–MS, determine the antioxidant activity, molecular and drug likenees of the identfied compounds. Data showed that the total phenolic content of the juice made with 30% seaweed was 32.2 + 0.5 μg/GAE, vitamin C 2.9 + 0.1 µg/mL while the antioxidant activity (DPPH IC50) was 46.8±3.3 mg/mL. Twenty compounds were identified of which three met the Lipinski’s rule of five. They were then docked with five enzymes involved in oxidative stress and inflammation (cytochrome P450, lipoxygenase, myeloperoxidase, NADPH oxidase, and Xanthin oxidase). Their binding energies (∆G: – 4.1 to – 6.3 Kcal/mol) were comparable to those of known commercial binders (∆G: – 5.0 to – 7.3 Kcal/mol) of each enzyme. Pharmacokinetic analyses showed excellent scores for the three compounds in regard to bioavailability, human intestinal absorption, and blood brain barrier. The sensory test value of the juice showed good odor, taste, and color, with a score between 4.7- 5.9. Overall, the functionalized juice displayed properies that make it potentially useful in the reduction of oxidative stress are related conditions, although in-vivo studies are needed.