Synthesis and α-Glucosidase Inhibitory Activity of Ursolic Acid, Lupeol, and Betulinic Acid Derivatives

Chemical constituents with their alpha-glucosidase inhibitory activity from the whole plant of Ceratophyllum demersum

From Ceratophyllum demersum growing in Vietnam, twelve compounds were isolated and structurally elucidated, including six previously undescribed compounds, demersones A-D (1-4), acetylvelutins A and B (8 and 9), together with six known compounds, (+)-cyclocolorenone (5), 1-hydroxycyclocolorenone (6), 10-hydroxycyclocolorenone (7), retusin (10), betulinic acid (11), and lupeol (12). The chemical structures and stereochemistry of 1-12 were identified through analysis of spectroscopic data (1D and 2D NMR and HRESIMS), ECD data, and DFT calculation. Notably, this is the first time that humulene-type (1 and 2), guaiane-type (3), and aromadendrane-type (4-7) sesquiterpenoids have been reported in this genus. Compounds 8 and 9 are the first examples of 8-acetoxyflavones found in nature. Upon evaluation of the alpha-glucosidase of 1-3 and 5-12, it was found that 12 exhibited the highest potential with an IC50 value of 15.4 ± 1.1 μM. The molecular docking of 3 and 8 was further studied.

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.