Glucose Uptake-Stimulating Galloyl Ester Triterpenoids from Castanopsis sieboldii

• Published in: Journal of natural products (Washington, D.C.) Vol. 83; no. 10; pp. 3093 - 3101
• Main Authors: Kim, Hyun Woo, Park, Eun Jin, Cho, Hyo Moon, An, Jin-Pyo, Chin, Young Won, Kim, Jinwoong, Sung, Sang Hyun, Oh, Won Keun
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society and American Society of Pharmacognosy 23.10.2020; Amer Chemical Soc
• Subjects: Chemistry, Medicinal; Life Sciences & Biomedicine; Pharmacology & Pharmacy; Plant Sciences; Science & Technology; INSULIN; CORE; TRANSPORT; ACTIVATED PROTEIN-KINASE; THERAPEUTIC TARGET; TANNINS
• ISSN: 0163-3864; 1520-6025
• DOI: 10.1021/acs.jnatprod.0c00645

Using molecular networking-guided isolation, three new galloyl ester triterpenoids (1–3), two new hexahydroxydiphenic acid-conjugated triterpenoids (6 and 7), and four known compounds (4, 5, 8, and 9) were isolated from the fruits and leaves of Castanopsis sieboldii. The chemical structures of 1–3, 6, and 7 were elucidated on the basis of interpreting their NMR, HRESIMS, and ECD spectra. All compounds (1–9) were evaluated for their glucose uptake-stimulating activities in differentiated adipocytes using 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)­amino]-d-glucose as a fluorescent-tagged glucose probe. Compounds 2 and 9 resulted in a 1.5-fold increase in glucose uptake. Among them, compound 2 from the fruits showed an upregulation of p-AMPK/AMPK ratio in differentiated C2C12 myoblasts to support the mechanism proposed of glucose uptake stimulation.