Enzyme Inhibitory Activities, Phenolic Profile, and In Silico Studies of Sorbus torminalis Tree Bark Methanol Extract

The different parts of Sorbus torminalis (L.) Crantz are used in traditional medicine for various conditions such as cardiac diseases, cough, and diabetes, indicating its significant medicinal potential. Therefore, the current investigation aimed to reveal the phenolic composition of the poorly studied S. torminalis methanol extract of the bark, as well as its capacity to inhibit enzymes relevant to cardiovascular, neurodegenerative, and metabolic diseases. A total of 28 phenolic components, including 20 procyanidins aglycones (A- and B-type), four procyanidin glycosides, catechin and its glycoside, and two (epi)catechin derivatives, were detected using LC-MS. The contents of total polyphenols (6.22 %), total tannins (3.04 %), condensed tannins (0.70 %), and total flavonoids (0.24 %) were determined spectrophotometrically, highlighting the considerable phenolic richness of the examined plant material. The concentration-dependent ability to inhibit α-amylase (IC₅₀=130 μg /mL), α-glucosidase (IC₅₀=312.13 μg /mL), acetylcholinesterase (IC₅₀=156.46 μg /mL), butyrylcholinesterase (IC₅₀=217.68 μg /mL), and angiotensin-converting enzyme (IC₅₀=36.77 μg /mL) was demonstrated in vitro. The in silico approach showed that catechin, procyanidin B2 and C1, S. torminalis bark constituents, can form stable complexes with the target enzymes but with different binding affinity. The results supported the medicinal potential of S. torminalis bark and significantly expanded our knowledge of its chemistry, justifying further research.