Secoiridoid and iridoid glucosides from the leaves of Fraxinus griffithii

Phytochemical investigation of the dried leaves of Fraxinus griffithii collected in Okinawa has led to the isolation of three new secoiridoid glucosides, griffithosides A-C (1-3), and one new iridoid glucoside, 7-epi-7-O-(E)-caffeoylloganic acid (4), along with eight known secoiridoid glucosides (5-12). The structures of these compounds were elucidated by means of NMR, MS, and other spectroscopic techniques, as well as comparison with literature data. The isolated compounds were tested for radical-scavenging activity. Among them, compounds 3, 4, and 7 exhibited substantial radical-scavenging activity.