New octadecanoid derivatives from the seeds of Ipomoea nil

摘要

Four new octadecanoid derivatives(1–4) including a pair of enantiomers(1/2), along with 12 known analogues(5–16), were isolated from the seeds of Ipomoea nil. Their structures were determined by detailed spectroscopic analyses and comparison with reported data of structurally related compounds, with the absolute configurations of 1 and 2 being assigned by an in situ dimolybdenum ECD method. Our bioassays revealed that these isolates did not show ABTS radical scavenging activity while 10 and 13 displayed better a-glucosidase inhibitory activity than the positive control acarbose(IC_(50) 167.7 ± 1.55 μmol×L^(-1)), with IC_(50) of 92.73 ± 3.12 and 11.39 ± 2.18 μmol×L^(-1), respectively.