Chemical profiling and antidiabetic potency of Paeonia delavayi: Comparison between different parts and constituents

• Published in: Journal of pharmaceutical and biomedical analysis 2021-05, Vol.198, p.113998-113998, Article 113998
• Main Authors: Huang, Qian, Chen, Ji-Jun, Pan, Yang, He, Xiao-Feng, Wang, Yuan, Zhang, Xue-Mei, Geng, Chang-An
• Format: Article
• Language: English
• Subjects: Antidiabetic effects; Chemical comparison; LCMS analyses; Paeonia delavayi; PTP1B/TCPTP selective inhibitors
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/j.jpba.2021.113998

[Display omitted] •57 compounds including three new ones were identified by MS/MS and UV patterns.•PCA distinguished four parts of P. delavayi by characteristic constituents.•Antidiabetic effects of P. delavayi and compounds were evaluated on four enzymes.•Enzyme kinetics and docking study supported the ligand-target interactions.•Akebonic acid was a mix-type inhibitor of PTP1B by interacting with sites B and C. Paeonia delavayi (Paeoniaceae), an endemic plant mainly distributed in southwest China, is always used as the substitute of P. suffruticosa due to their morphological and pharmacological similarity. In the previous study, P. suffruticosa was revealed with antidiabetic potency, whereas the chemical difference and antidiabetic property between different parts of P. delavayi has not yet been studied. This paper was designed to clarify the chemical constituents and antidiabetic potency of P. delavayi by LCMS analysis and enzyme inhibition on α-glucosidase, PTP1B, TCPTP, and DPP4. By interpretation of their UV absorptions and MS fragmentations, and/or comparison with reference samples, 57 constituents comprising 15 flavonoids, 10 monoterpene glycosides, eight triterpenoids, seven galloyl glucoses, six N-containing compounds, five gallic acids, two acetophenones, and four other types of compounds were identified from the different parts of P. delavayi. Moreover, two new monoterpene aglycones (42 and 47) and one new noroleanane triterpenoid (51) were speculated by their MS/MS fragmentation rules. Principal component analysis (PCA) suggested the chemical resemblance between root core and root bark which could be well differentiated with the leaves and stems by their characteristic constituents (monoterpene glycosides, flavonoids, and acetophenones). All the four parts (200 μg/mL) showed obvious inhibition on α-glucosidase and PTP1B (81.2%–98.5%), but moderate to weak inhibition on TCPTP and DPP4 (19.5%–34.9%). Nine compounds representing five main types of constituents in Paeonia plants were assayed for their antidiabetic effects, indicating flavonoids and triterpenoids were the main active substances regarding to the four enzymes. Luteolin displayed obvious activity on α-glucosidase, PTP1B, and TCPTP with IC50 values of 94.6, 136.3, and 157.3 μM, and akebonic acid could inhibit α-glucosidase and PTP1B with IC50 values of 73.5 and 57.8 μM. Luteolin and akebonic acid were recognized as competitive inhibitors of α-glucosidase, but anticompetitive and mix-typ