| The genus Cornus, commonly known as dogwood, is widely distributed in eastern Asia, and eastern and western parts of North America. Anecdotal reports indicate that several plants in Cornus species are effective for the treatment of various illnesses. Although, Cornus plants are well known for its medicinal properties, very little work has been done on the isolation and identification of bioactive compounds. A bioassay-directed investigation of Cornus kousa, Cornus mas, Cornus controversa and Cornus alternifolia fruits resulted in the isolation and characterization antioxidant, anti-inflammatory, anti-cancer and anti-diabetic anthocyanins, delphinidin 3-O-glucoside (1), delphinidin 3-O-rutinoside (2), delphinidin 3-O-galactoside (3), cyanidin 3- O-galactoside (4), pelargonidin 3-O-galactoside (5) and cyanidin 3-O-glucoside (6). Acid hydrolysis of the anthocyanin-enriched fruit extracts resulted in the isolation of anthocyanidins, delphinidin (7), cyanidin ( 8), pelargonidin (9), petunidin (10) and malvidin (11). The anthocyanins in Cornus fruits extracts were quantified by HPLC. The amount of anthocyanins 1, 2 and 6 in C. alternifolia, C. controversa and C. mas were determined to be 8-10 times higher than other common fruit sources of anthocyanins.; An investigation of the non-pigmented fraction of C. kousa ripened and unripened fruits resulted in the isolation of ursolic acid ( 12), beta-sitosterol (13), cornin (14), kaempherol 3-O-rhamnoside (15), myricetin 3- O-rhamnoside (16), and kaempherol 3-O-glucoside (17), and stenophyllin (18). Both ursolic acid ( 12) and beta-sitosterol (13) were also isolated from the ripened fruits of C. kousa, C. controversa and identified in C. alternifolia.; Anthocyanins and anthocyanidins were tested for lipid peroxidation, cyclooxygenase (COX-1 and-2) enzymes and tumor cell proliferation inhibitory activities. Anthocyanins 1 and 2 inhibited lipid peroxidation by 71 and 68%, respectively, at 50 mug/ml. Similarly, they inhibited COX-1 enzymes by 39 and 49% and COX-2 enzyme by 54 and 48%, respectively, at 100 mug/mL. In addition, anthocyanins 1 and 2 displayed 50% growth inhibition (IC50) at 21 and 38, 25 and 30, 50 and 76, 60 and 100, and 75 and 100 mug/mL, against HCT-116 (colon), MCF-7 (breast), NCI-H460 (lung), SF-268 (Central Nervous System, CNS), and AGS (stomach), human tumor cell lines, respectively. The most active anthocyanidin malvidin (11) inhibited colon, breast, lung, central nervous system and stomach cell growth by 76, 75, 68, 41, and 69%, respectively, at 200 mug/mL. (Abstract shortened by UMI.)... |
