Isolation of neuroprotective compounds from Phlomis umbrosa

Phlomis umbrosa Turcz (Labiatae) is a perennial herb growing in North China. Roots of P. umbrosa has been used in traditional Chinese medicine for reduction of swelling, staunch bleeding, eliminating phlegm and detoxicating for thousands of years. Our phytochemical investigation to find natural compounds with protective activity against degeneration of retinal ganglion cells led to the isolation of ten compounds, ursolic acid (1), oleanolic acid-3-O-α-L-rhamnopyranoside (2), daucosterol (3), hederagenin-3-O-α-L-arabinopyranoside (4), sweroside (5), caffeic acid (6), esculetine (7), 3,4-dihydroxy bezaldehyde (8), loganin (9), and vanilic acid (10) from ethyl acetate fraction of methanol extract of Phlomis umbrosa. The structures of 1-10 were elucidated on the basis of NMR data and comparison with the literature. Their structure determination and biological activities will be presented.