α-Glucosidase Inhibition Kinetics and Molecular Docking Studies with the Bioactive Constituents from Canna indica L. Rhizome Extract

Potential antithrombotic effect of two new phenylpropanoid sucrose esters and other secondary metabolites of Canna indica L. rhizome

Canna indica L. has been traditionally used to treat various diseases. Based on previously reported antithrombotic effect for this plant, two new phenylpropanoid sucrose esters (canindicoside A (1) and canindicoside B (2)) and seven known compounds: nepetoidin B (3), caffeic acid (4), ferulic acid (5), (R)-(+)-rosmarinic acid (6), isorinic acid (7), (S)-(-)-rosmarinic acid (8) and (S)-(-)-rosmarinic acid methyl ester (9) were isolated from the ethyl acetate extract. Compounds were elucidated by NMR and MS spectroscopic methods. The antiplatelet effect was evaluated using turbidimetric method. Anticoagulant activity was examined by measuring activated partial thromboplastine time (APTT), prothrombin time, and thrombine time (TT). It was shown for the first time that both new phenylpropanoid sucrose esters 1 and 2, 7 and 9 displayed dose-dependent antiplatelet effects. 2 and 9 had the highest inhibitory activity on both adenosine diphosphate (ADP)- and collagen-induced platelet aggregation. Moreover, 1, 7 and 9 also exhibited anticoagulant activity. At 0.4 mg/mL, both 1 and 7 prolonged APTT compared to the negative control (p < 0.05), suggesting the possible inhibitory impact on the intrinsic coagulation pathway. Moreover, 9 at 0.4 mg/mL exerted higher TT values than the negative control (p < 0.05). C. indica and its bioactive phytochemicals are potential candidates for development of anti-thrombosis therapy.

Two New Acylated Sucroses From the Roots of Canna indica L. and Their Antioxidant Activity

Two new acylated sucroses, (6- O-axetoxyl)- β-d-fructofuranosyl-(2→1)-(6- O-feruloyl- α- d-glucopyranoside (1) and (6- O-axetoxyl)- β-d-fructofuranosyl-(2→1)-(6- O-( E)- p-coumaroyl- α- d-glucopyranoside (2), and four known compounds, 2-(3′,4′-dihydroxyphenyl)-1-propanol-4′- O-[4′′′-hydroxy-3′′′,5′′′-dimethoxybenzoyl-(→6′′)- β-d-fructofuranoside (3), tryptophol glucoside (4), corchonoside C (5), and 2-hydroxy-5-(2-hydroxyethyl)phenyl β-d-fructofuranoside (6), were isolated from the roots of Canna indica L. (Cannaceae). Their structures were determined by extensive analysis of HR-ESI-MS, 1D, and 2D NMR spectral data, as well as by comparison of these with those reported in the literature. Antioxidant activity of compounds 1-6 were evaluated by peroxyl radical absorbance capacity assay. Compounds 1 and 3 neutralized high amounts of peroxyl radical. At a concentration of 1 µM, their ORACROO* values were 3.07 ± 0.15 and 4.27 ± 0.30, respectively, many times greater than that of trolox, which was used as an internal standard. At 10 µM, the peroxyl radical absorbance capacity of compounds 1 and 3 exhibited equivalents to 15.60 ± 0.22 and 24.91 ± 0.43 times the net protection by 1 µM of trolox.

Cannadicas A and B: two new oligosaccharide esters from the roots of Canna indica L

Two new sucrose derivatives, named as cannadica A (1) and cannadica B (2), and eight known compounds, 6'-O-acetyl-3-O-(E)-p-coumaroylsucrose (3), heterophylloside C (4), 6'-O-vanilloylarbutin (5), isotachioside (6), 2,6-dimethoxy-p-hydroquinone 1-O-β-D-glucopyranoside (7), 3,5-dimethoxy-p-hydroquinone 1-O-β-D-glucopyranoside (8), benzyl glucoside (9), and 3,4-dihydroxybenzaldehyde (10) were isolated from the roots of Canna indica L. by various chromatographic methods. Their structures were established by extensive spectroscopic analysis (UV, IR, HR-ESI-MS and NMR) and by comparison of the spectral data with those reported in the literature. Compounds 1-10 were evaluated their antioxidant activity by peroxyl radical absorbance capacity assay. Compounds 4 and 5 exhibited the most peroxyl radical absorbance capacity. At concentration of 1 µM, their ORAC_ROO* values were 4.86 ± 0.39 and 3.11 ± 0.26, respectively, fold-up to that of trolox as an internal standard.