Isolation of a New Phenolic Ester and Biflavonoids From Taxus mairei Leaves: Dual Mechanisms Targeting α-Glucosidase and High-Glucose-Induced VEGF Expression

[摘要] ObjectiveDiabetes mellitus and its complications, specifically diabetic retinopathy (DR), require novel therapeutics with enhanced safety profiles. Guided by the traditional use of Taxus mairei, this study aimed to isolate bioactive constituents from its leaf extracts and investigate their dual potential in regulating metabolic enzymes and protecting retinal cells against hyperglycemic stress.MethodsThe bioactive n-butanol fraction of T. mairei leaves was subjected to phytochemical isolation and structural elucidation. The isolated compounds were evaluated for inhibitory activities against α-glucosidase and α-amylase, supported by molecular docking analysis to understand structure–activity relationships. Furthermore, the potential retinal-protective effects were assessed using ARPE-19 retinal pigment epithelial cells under high-glucose conditions, focusing on cell viability and vascular endothelial growth factor A (VEGF-A) secretion.ResultsNine compounds were identified, including a novel phenolic ester, 3-hydroxy-2-(3-hydroxy-4-methoxyphenyl)propyl 2-(4-hydroxyphenyl)acetate (1), and eight known constituents. The biflavonoids—amentoflavone (6), 7,7″-di-O-methylamentoflavone (7), and sotetsuflavone (8)—exhibited potent α-glucosidase inhibition (IC50 values of 0.51–1.10 μg/mL) superior to acarbose, along with moderate α-amylase suppression. Docking studies indicated that compact folded conformations and extensive hydrogen-bonding networks strongly enhance binding affinity. Conversely, while compound 1 lacked enzyme inhibitory activity, it significantly attenuated high-glucose-induced VEGF-A overproduction and restored cell viability in ARPE-19 cells without cytotoxicity.ConclusionsThis study highlights T. mairei as a source of bioactive compounds with complementary antidiabetic potential. The identified biflavonoids offer promise for postprandial glycemic control, whereas the novel phenolic ester showed a distinct protective activity profile against high-glucose-induced VEGF-A overproduction. These findings suggest that T. mairei constituents have the potential to be developed into multifunctional therapeutics for diabetes and its microvascular complications.

[发布日期] 2026-07-01

[关键词] Taxus mairei;amentoflavone;α-glucosidase inhibition;diabetic retinopathy;retinal pigment epithelium