Response surface modeling of betulinic acid pre-concentration from medicinal plant samples by miniaturized homogenous liquid–liquid extraction and its determination by high performance liquid chromatography

Synthesis of ursolic acid arylidene-hydrazide hybrid compounds and investigation of their cytotoxic and antimicrobial effects

In this study, 13 new hybrid compounds (7a-m) were synthesised starting from ursolic acid, and their cytotoxic activities were investigated on the BEAS-2B and A549 cell lines. In addition, the synthesised compounds were tested against Staphylococcus aureus, Escherichia coli, and Candida albicans to determine their anti-microbial properties. The hybrid compounds that exhibited the lowest cytotoxicity against the BEAS-2B were 7k, 7b, and 7g. The cytotoxicity of the compounds against A549 was evaluated, the IC50 value of 7k, 7b, and 7g are found as 0.15 µM, 0.31 µM, and 0.26 µM, respectively. The results showed that the selectivity of 7k was 7 times higher than doxorubicin against the A549 cells. According to the antimicrobial activity studies 7c is found as the most effective compound against S. aureus. Almost all compounds showed a similar inhibition potential against E. coli and C. albicans.

Synthesis of Polyurethane Membranes Derived from Red Seaweed Biomass for Ammonia Filtration

The development of membrane technology is rapidly increasing due to its numerous advantages, including its ease of use, chemical resistant properties, reduced energy consumption, and limited need for chemical additives. Polyurethane membranes (PUM) are a particular type of membrane filter, synthesized using natural organic materials containing hydroxy (-OH) groups, which can be used for water filtration, e.g., ammonia removal. Red seaweed (Rhodophyta) has specific molecules which could be used for PUM. This study aimed to ascertain PUM synthesis from red seaweed biomass (PUM-RSB) by using toluene diisocyanate via the phase inversion method. Red seaweed biomass with a particle size of 777.3 nm was used as starting material containing abundant hydroxy groups visible in the FTIR spectrum. The PUM-RSB produced was elastic, dry, and sturdy. Thermal analysis of the membrane showed that the initial high degradation temperature was 290.71 °C, while the residue from the thermogravimetric analysis (TGA) analysis was 4.88%. The PUM-RSB section indicates the presence of cavities on the inside. The mechanical properties of the PUM-RSB have a stress value of 53.43 MPa and a nominal strain of 2.85%. In order to optimize the PUM-RSB synthesis, a Box–Behnken design of Response Surface Methodology was conducted and showed the value of RSB 0.176 g, TDI 3.000 g, and glycerin 0.200 g, resulting from the theoretical and experimental rejection factor, i.e., 31.3% and 23.9%, respectively.

Sorbus umbellata (Desf.) Fritsch var. umbellata Leaves: Optimization of Extraction Conditions and Investigation Antimicrobial, Cytotoxic, and β-Glucuronidase Inhibitory Potential

This study aimed to optimize the extraction conditions for Sorbus umbellata (Desf.) Fritsch var. umbellata leaves to maximize the phenolic content and their antioxidant activity and to investigate β-glucuronidase (GUS) enzyme inhibitory, antimicrobial and cytotoxic potentials of the extracts obtained under optimum conditions. The optimum extraction conditions were found to be 78.2 and 79.7% solvent, 73.1 and 71.5 °C, and 89.9 and 88.8 min to maximize phenolic content and antioxidant activity, respectively. Low values of coefficient of variations indicate the high reliability and reproducibility of the conducted extraction experiments. Bioactivity results showed that extracts had cytotoxic effect on the MCF-7 and A549 cells where the highest cell proliferation inhibition was observed for the A549 cell line (71.8% at 150 μg/mL). Staphylococcus aureus showed highest zone of inhibition (19.3 mm) in all bacteria followed by Escherichia coli. Additionally, extracts displayed potential GUS inhibitory activity. In conclusion, Sorbus umbellata leaf extract can be obtained by optimized cost-saving extraction and has a potential bioactivity to be utilized as a food ingredient for high value-added products and/or nutraceuticals development where it can combat oxidative stress and GUS mediated reactive metabolite formation.