Two undescribed iridoids from the flowers of Sesamum indicum L

From the flowers of Sesamum indicum L., two novel iridoid compounds sesamiridol (1) and sesamiridoside (2) have been successfully isolated. Alongside these, five known iridoids were identified: lamiolactone (3), sesamoside (4), lamalbide (5), shanzhiside methyl ester (6), phloyoside III (7). The two-dimensional structures of compounds 1 and 2 were ascertained by means of IR, UV, NMR, and HR-ESI-MS, corroborated by comparison with relevant literature data. The configurations of these novel compounds were clarified via NOESY spectroscopy, ECD calculations, and acid hydrolysis. Moreover, an evaluation of the antioxidant activities of all compounds were conducted.