Anthocyanin Profile and Antioxidant Property of Anti-asthma Flowers of Cordyline terminalis (L.) Kunth (Agavaceae)

Cordyline terminalis flower is traditionally used to treat asthma and the purple color of the flower is suggestive of anthocyanins. The purpose of this study was to characterize and determine the antioxidant property of anthocyanins from C. terminalis purple flowers. Five anthocyanins, cyanidin 3,5-di- O-β-glucopyranoside (2.6 ± 0.2 mg/g fr. wt) (1), peonidin 3,5-di- O-β-glucopyranoside (2.8 ± 0.3 mg/g fr. wt) (2), cyanidin 3- O-β-(6″- O- E- p-caffeoylglucopyranoside)-5- O-β-glucopyranoside (3.2 ± 0.2 mg/g fr. wt) (3), cyanidin 3- O-β-(6″- O- E- p-coumaroylglucopyranoside)-5- O-β-glucopyranoside (6.2 ± 0.4 mg/g fr. wt) (4), and peonidin 3- O-β-(6″- O- E- p-coumaroylglucopyranoside)-5- O-β-glucopyranoside (9.8 ± 0.2 mg/g fr. wt) (5), were isolated from the flowers of C. terminalis by a combination of chromatographic techniques. Their structures were established by UV-visible, NMR, and ESI-MS. The extract exhibited appreciable antioxidant activity (IC50 ± SD = 13.1 ± 0.8 μg/mL) against quercetin (IC50 ± SD = 4.5 ± 0.4 μg/mL) compared to the individual anthocyanins (IC50 ± SD = 13.8 ± 0.5 to 16.4 ± 0.7 μg/mL) when measured using the 2,2-diphenyl-1-picryl-hydrazyl method. Cordyline terminalis flowers extract may be justified for use and standardization as herbal remedy for asthma.