Phytochemical profiling of Symplocos tanakana Nakai and S. sawafutagi Nagam. leaf and identification of their antioxidant and anti-diabetic potential

• Published in: Journal of pharmaceutical and biomedical analysis 2023-09, Vol.233, p.115441-115441, Article 115441
• Main Authors: Seong, Su Hui, Kim, Bo-Ram, Park, Jong-Soo, Jeong, Do Yun, Kim, Tae-Su, Im, Sua, Jeong, Jin-Woo, Cho, Myoung Lae
• Format: Article
• Language: English
• Subjects: Advanced glycation end-products; alpha-Glucosidases; Antioxidants - chemistry; Glycation End Products, Advanced - chemistry; Methylglyoxal; Phytochemicals - analysis; Plant Extracts - chemistry; Plant Leaves - chemistry; Pyruvaldehyde - analysis; Quercetin-3-O-(6′-O-galloyl)-β-D-galactopyranoside; Symplocos sp; Tellimagrandin II; α-Glucosidase
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/j.jpba.2023.115441

Symplocos sp. contains various phytochemicals and is used as a folk remedy for treatment of diseases such as enteritis, malaria, and leprosy. In this study, we discovered that 70% ethanol extracts of Symplocos sawafutagi Nagam. and S. tanakana Nakai leaves have antioxidant and anti-diabetic effects. The components in the extracts were profiled using high-performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry; quercetin-3-O-(6′′-O-galloyl)-β-d-galactopyranoside (6) and tellimagrandin II (7) were the main phenolic compounds. They acted as strong antioxidants with excellent radical scavenging activity and as inhibitors of non-enzymatic advanced glycation end-products (AGEs) formation. Mass fragmentation analysis demonstrated that compounds 6 and 7 could form mono- or di-methylglyoxal adducts via reaction with methylglyoxal, which is a reactive carbonyl intermediate and an important precursor of AGEs. In addition, compound 7 effectively inhibited the binding between AGE2 and receptor for AGEs as well as the activity of α-glucosidase. Enzyme kinetic study revealed that compound 7 acts as a competitive inhibitor of α-glucosidase, through interaction with the active site of the enzyme. Therefore, compounds 6 and 7, the major constituents of S. sawafutagi and S. tanakana leaves, are promising for developing drugs for preventing or treating diseases caused by aging and excessive sugar consumption. [Display omitted] •70% ethanol extracts of leaves from Symplocos sp. were profiled using LC-Q-TOF-MS.•Two key phenolic compounds exhibited anti-glycation and anti-diabetic activity.•Quercetin-3-O-(6′-O-galloyl)-β-d-galactopyranoside and tellimagrandin II inhibited protein glycation by trapping RCCs.•Quercetin-3-O-(6′-O-galloyl)-β-d-galactopyranoside and tellimagrandin II may be used to develop novel anti-diabetic drugs.