Rugonidines A–F, Diastereomeric 1,6-Dioxa-7,9-diazaspiro[4.5]dec-7-en-8-amines from the Leaves of Alchornea rugosa

Abstract

Rugonidines A−F (1−6), three pairs of novel configurationally semistable diastereomers featuring an unprecedented 1,6-dioxa-7,9-diazaspiro[4.5]dec-7-en-8-amine scaffold, were isolated from Alchornea rugosa based on MS/MS-based molecular networking analysis. Their structures were elucidated by NMR spectroscopy in combination with quantum-chemical calculations. Compounds 1−3 showed a significant increase in glucose uptake level in differentiated 3T3-L1 adipocytes using 2deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-D-glucose (2-NBDG) as a fluorescent-tagged glucose probe.