Inhibitory mechanism of Tangzhiqing on sucrase: changed inhibitory kinetics and secondary molecular conformation of sucrase and chemical components from Tangzhiqing
- 1Second Affiliated Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, 300250 China
- 2Tianjin University of Traditional Chinese Medicine, Tianjin, 301617 China
Abstract
Background: Tangzhiqing (TZQ), a herbal formula, has postprandial hypoglycemic effects on sucrose in humans. Sucrase, an α-glucosidase, breaks down sucrose into glucose and fructose. This study investigated the inhibitory activity of TZQ against sucrase and the associated conformational changes.
Methods: Inhibitory activity was assessed using sucrose as substrate. After confirming the suitable reaction concentrations and time, an assay of the inhibitory activity of TZQ against sucrase was performed with a series of TZQ concentrations. The inhibition kinetics were analyzed in the presence and absence of TZQ or acarbose (positive control). Secondary structure changes of sucrase were determined by circular dichroism spectroscopy. Components of TZQ were identified by UPLC-Q-TOF/MS, and molecular docking explored binding interactions.
Results: TZQ showed notable inhibitory activity against sucrase in a reversible and uncompetitive manner. The half-maximal inhibitory concentrations of TZQ and acarbose were 1.49 ± 0.07 and 3.94 ± 0.07 µg/mL (P < 0.01), respectively. Circular dichroism revealed that TZQ binding induced secondary structural rearrangement of sucrase, increasing α-helix and decreasing β-sheet content, thereby inhibiting enzyme activity. A total of 64 chemical ingredients were identified from TZQ. Among these, the potential active ingredients—including paeoniflorin, vitexin, chlorogenic acid, and salvianolic acid A—exhibited binding energies below − 5 kcal/mol. These compounds strongly affected the structure of sucrase via π accumulation or salt bridge formation, leading to enzyme inhibition and reduced glucose.
Conclusion: These findings provide new insights into the inhibitory mechanism of TZQ on sucrase, supporting its potential as a novel α-glucosidase inhibitor for the management of type 2 diabetes mellitus.
Supplementary Information: The online version contains supplementary material available at https://doi.org/10.1186/s12906-026-05403-5.
Related
- Beyond Sinus Rhythm: Rhythm Control and Mechanism-Based Secondary Prevention in Atrial Fibrillation–Related Stroke
- Bacillus velezensis 802 with antagonistic activity against Aspergillus flavus: genome characterization, secondary metabolites and antifungal mechanism
- Dual-barrier mechanism of superinfection exclusion in Newcastle disease virus: nucleoprotein and hemagglutinin-neuraminidase cooperate to block secondary infection
- Mechanism-defined secondary hypertension enables precision diagnosis and treatment: an evidence review
- The conformation-selective PI3Kδ inhibitor roginolisib in patients with advanced or metastatic cancer, including metastatic uveal melanoma: first-in-human clinical trial
BibTeX
@article{li2026inhibitory,
title = {{Inhibitory mechanism of Tangzhiqing on sucrase: changed inhibitory kinetics and secondary molecular conformation of sucrase and chemical components from Tangzhiqing}},
author = {Yanfen Li and Mengyao Zhu and Ruihua Wang and Xin Xia and Ting Jiang and Fengying Wang and Xuelian Gao and Shuang Tian and Ziqiang Li and Yuhong Huang},
journal = {BMC Complementary Medicine and Therapies},
year = {2026},
month = may,
doi = {10.1186/s12906-026-05403-5},
url = {https://doi.org/10.1186/s12906-026-05403-5},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Inhibitory mechanism of Tangzhiqing on sucrase: changed inhibitory kinetics and secondary molecular conformation of sucrase and chemical components from Tangzhiqing
AU - Yanfen Li
AU - Mengyao Zhu
AU - Ruihua Wang
AU - Xin Xia
AU - Ting Jiang
AU - Fengying Wang
AU - Xuelian Gao
AU - Shuang Tian
AU - Ziqiang Li
AU - Yuhong Huang
PY - 2026
DA - 2026/05/13
JO - BMC Complementary Medicine and Therapies
DO - 10.1186/s12906-026-05403-5
UR - https://doi.org/10.1186/s12906-026-05403-5
AB - Background: Tangzhiqing (TZQ), a herbal formula, has postprandial hypoglycemic effects on sucrose in humans. Sucrase, an α-glucosidase, breaks down sucrose into glucose and fructose. This study investigated the inhibitory activity of TZQ against sucrase and the associated conformational changes. Methods: Inhibitory activity was assessed using sucrose as substrate. After confirming the suitable reaction concentrations and time, an assay of the inhibitory activity of TZQ against sucrase was performed with a series of TZQ concentrations. The inhibition kinetics were analyzed in the presence and absence of TZQ or acarbose (positive control). Secondary structure changes of sucrase were determined by circular dichroism spectroscopy. Components of TZQ were identified by UPLC-Q-TOF/MS, and molecular docking explored binding interactions. Results: TZQ showed notable inhibitory activity against sucrase in a reversible and uncompetitive manner. The half-maximal inhibitory concentrations of TZQ and acarbose were 1.49 ± 0.07 and 3.94 ± 0.07 µg/mL (P < 0.01), respectively. Circular dichroism revealed that TZQ binding induced secondary structural rearrangement of sucrase, increasing α-helix and decreasing β-sheet content, thereby inhibiting enzyme activity. A total of 64 chemical ingredients were identified from TZQ. Among these, the potential active ingredients—including paeoniflorin, vitexin, chlorogenic acid, and salvianolic acid A—exhibited binding energies below − 5 kcal/mol. These compounds strongly affected the structure of sucrase via π accumulation or salt bridge formation, leading to enzyme inhibition and reduced glucose. Conclusion: These findings provide new insights into the inhibitory mechanism of TZQ on sucrase, supporting its potential as a novel α-glucosidase inhibitor for the management of type 2 diabetes mellitus. Supplementary Information: The online version contains supplementary material available at https://doi.org/10.1186/s12906-026-05403-5.
SN - 2662-7671
ER -