• Korean Journal of Pharmacognosy
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• v.46 no.2
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• pp.105-108
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• 2015

To establish the anti-diabetic(α-glucosidase inhibitory) activity of D. lotus leaf extract, isolate and identify the constituents responsible for the activity. The methanolic extract of leaves was partitioned between water, n-butanol and ethyl acetate. Bio-assay guided fractionation, based on inhibition of ;${\alpha}$-glucosidase, allowed isolation and identification of the active components. Liquid chromatography/mass spectrometry(LC/MS), ¹ H-NMR and ¹³ C-NMR spectra analyses demonstrated that the active compound was myricetin-3-O-;${\alpha}$-L-rhamnoside(1). Compound 1 demonstrated a strong inhibition on the α-glucosidase, in vitro and ;${\alpha}$-glucosidase inhibitory value was calculated as 98.08%, when that of a reference drug, acarbose was estimated as 83.03%. The present study indicates compound 1 could be considered as an ;${\alpha}$-glucosidase inhibitor and developed as an important antidiabetes agent for type II diabetes therapy.

• Food Science and Preservation
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• v.21 no.2
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• pp.254-263
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• 2014

This study was carried out to analyze the effects of water and 70% ethanol extract on the antioxidative and antidiabetic activities of Smilax china L., a vine shrub belonging to the lily family. The activities of the extracts were measured based on the total phenolic and flavonoid contents and through on the results of the antioxidant tests, such as the electron-donating ability, ABTs radical scavenging activities, SOD-like activity, xanthine oxidase inhibition effect, antioxidant protection factor (PF), TBARs content and ACE inhibition activity, and ${\alpha}$-glucosidase, and ${\alpha}$-amylase inhibition activity. The resulting total phenolic and flavonoid contents of the 70% ethanol extract from S. china L. were greater than those of the water extract from S. china L. With regard to the results of the antioxidant tests, such as the electron-donating ability, ABTs radical scavenging activity, SOD-like activity, xanthine oxidase inhibition effect, antioxidant protection factor (PF), and TBARs content, those from the 70% ethanol extract from S. china L. were greater than those from the water extract from S. china L. Also, with regard to the ACE inhibition effect and ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibition, those from the 70% ethanol extract from S. china L. were greater than those from the water extract from S. china L. All these findings show that the 70% ethanol extract from S. china L. has greater antioxidative and antidiabetic effects and can be used as a preventive agent for oxidation and diabetes.