Evaluation of modified benzaldehyde derivatives as dual α-glucosidase and α-amylase inhibitors: a viable alternative to acarbose

The inhibitory effects of the active constituent isolated from Periploca sepium barks and its derivatives against α-glucosidase and α-amylase were studied. The active constituent was identified as 4-methoxy-2-hydroxybenzaldehyde by various spectral analyses. 4-Methoxy-2-hydroxybenzaldehyde was 5.44 times more effective at blocking α-amylase than acarbose, but it reduced its blocking ability against α-glucosidase by 0.57 times. The K_m values for α-glucosidase and α-amylase did not change with different amounts of 4-methoxy-2-hydroxybenzaldehyde, which is typical of non-competitive inhibition. To ascertain the structure–activity relationships, 3,4-dihydroxybenzaldehyde and 3,5-dihydroxybenzaldehyde demonstrated inhibitory activities against α-glucosidase. With regard to α-amylase, 2,4,5-trihydroxybenzaldehyde exhibited the most efficacious inhibitory effect, followed by 2,3,4-trihydroxybenzaldehyde, 2,4,6-trihydroxybenzaldehyde, and 3,4,5-trihydroxybenzaldehyde. The combination of benzaldehyde with hydroxyl, methyl, or methoxy groups suggests the potential for benzaldehyde to serve as a parent compound for the development of selective inhibitors. The results indicate that 3,4-dihydroxybenzaldehyde, 3,5-dihydroxybenzaldehyde, 2,5-dihydroxybenzaldehyde, 2,4,5-trihydroxybenzaldehyde, and 2,3,4-trihydroxybenzaldehyde may prove beneficial in alleviating diabetic pathological conditions.