Antioxidant and α-Amylase Inhibitory Compounds from Aerial Parts ofVarthemia iphionoidesBoiss

Abstract

Various extracts of aerial parts of Varthemia (Varthemia iphionoides Boiss) were investigated for radical-scavenging activity, antioxidative activity, and porcine pancreas alpha-amylase inhibitory activity. The ethanol and water extracts showed a pronounced 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, with inhibition of about 90% at a concentration of 100 microg/ml, and alpha-amylase inhibitory activity of about 70% at a concentration of 200 microg/ml by the 2-chloro-4-nitrophenyl alpha-maltotrioside (CNP-G3) degradation method. The ethanol extract was purified by column chromatography to give seven 3-methoxyflavones (1-7) and eudesmane sesquiterpene, selina-4,11(13)-dien-3-on-12-oic acid (8). The structures of these compounds were established by NMR, MS, and UV spectroscopy. Of 3-methoxyflavones, 5,7,4'-trihydroxy-3,6-dimethoxyflavone (1), 5,7,4'-trihydroxy-3,3'-dimethoxyflavone (2), and 5,4'-dihydroxy-3,7,3'-trimethoxyflavone (3,7,3'-tri-O-methyl-quercetin) (7) exhibited pronounced radical-scavenging activity. The antioxidative activity in the linoleic acid system was considerable in compounds 1, 2, and 5,4'-dihydroxy-3,6,7-trimethoxyflavone (4). Compounds 1, 2, 4, 5 (5,7,4'-trihydroxy-3-methoxyflavone), and 6 (5,4'-dihydroxy-3,7-dimethoxyflavone) showed markedly high inhibitory activity against porcine pancreas alpha-amylase. Eudesmane sesquiterpene did not show any activity.

Potent Natural Inhibitors of Alpha-Glucosidase and Alpha-Amylase against Hyperglycemia <em>in Vitro </em>and <em>in Vivo</em>

“…1b. Currently, several studies have reported that Rutin [58,59], Quercetin [60,61], and Catechin [62,63] are a group of flavonoids by isolated from T. sinensis plant, that have been shown to present blood glucose lowering properties in animal model and being potent compounds in the inhibition of alpha-amylase.…”

Natural sesquiterpenoids

“…This sesquiterpene has been obtained from Varthemia iphionoides. 280,281 The molecular cloning, expression and mechanistic study on the germacradienol/geosmin synthase from Streptomyces avermitilis have been described. 282 Moreover, it has been shown that a germacradienol/germacrane D synthase from Streptomyces coelicolor converts farnesyl diphosphate into geosmin.…”

Anti-diabetic activity of Chiliadenus iphionoides

“…There is some prior work showing Chiliadenus iphionoides biological activity. Water and ethanol extracts of the aerial parts from Chiliadenus iphionoides significantly reduced alpha amylase activity at concentrations of 100 g/ml in both the iodine starch assay and the CNP-G3 assay (Al-Dabbas et al, 2006). There is one published animal study documenting Chiliadenus iphionoides hypoglycemic activity (Afifi et al, 1997).…”