The antioxidant capacities, total phenolic contents (TPC), and total quercetin contents (TQC) of a red (Chenjujuck), a yellow (Sunpower), and a white (Grasier) onion cultivar were determined in this study. Onion was separated into edible portion and dry skin. In the case of edible portion, the yellow onion had the highest antioxidant activity, followed by the red onion. The white onion showed neither antioxidant activity nor quercetin compounds. On the other hand, the dry skin of the red onion showed higher antioxidant activity than yellow onion skin. The white onion skin had slight antioxidant activity, low TPC, and no quercetin compounds. In addition, the flavonoid compounds of the edible portion and dry skins of these colored onions were analyzed by UFLC(ultra-fast liquid chromatography). The major compounds were quercetin 3,4-diglucoside and quercetin 4- glucoside in yellow and red onion edible portion, whereas the major compounds in yellow and red onion skins were quercetin 4- glucoside, quercetin, and quercetin 3,4-diglucoside.

Background : This study of investigate the quality characteristics of Korean Dioscoreae Rhizoma by species and various processing methods. We used two types of species D. Rhizoma, which were the long type shape of D. batatas and short type shape of D. japoninca, respectively. Methods and Results : The reaction of D. Rhizoma with acetic acid and iodine showed light blue to blue colours, respectively. When compared with loss of drying between two species, the long type species was about 2% more higher than that of short type of species. When compared with processing methods, the both steamed and dried samples was more higher 2.0 - 3.0% than that of non-steamed samples. The contents of acid-insoluble ash samples with peel was relatively higher than that of samples containing no-peel. The results of TLC analysis also showed the same Rf and colours when compared with the standard of D. Rhizoma. However, both dried sample with peel (DWP) showed more clear spot than those of dried sample except peel (DEP) and both steamed and dried sample except peel (SDEP). Conclusion : We sincerely hope that this study will be contributed to the standardization and quality control of korean herbal medicines.

Background : 1-Deoxynojirimycin (DNJ) is a representative compound of the antidiabetic constituent in mulberry leaves (Morus alba L.). The hot water extracts of mulberry leaves were fermented with lactic acid bacteria in order to analysis the changes of the DNJ contents and α-glucosidase inhibition. Methods and Results : The mulberry leaves were extracted with hot water (121℃, 3 hr). The extracts were fermented with nine strains of lactic acid bacteria such as Lactobacillus acidophilus, in order to increase the contents of DNJ and α-glucosidase inhibition. DNJ contents in the fermented extracts were determinated by HPLC analysis. The α-glucosidase inhibition was mesured by comparing dose-inhibition curves of α-glucosidase and IC50 value. The DNJ contents after fermentation have increased in the almost fermented extracts. Especially, DNJ of the extracts fermented with L. acidophilus was increased from 8.38 ㎍ ㎖ -1 to 21.77 ㎍ ㎖-1. IC50 values of the α-glucosidase inhibition were shown to be decreased in the fermented extracts. The extracts fermented with L. casei KCTC 3109 was determined at 290.04 ㎍ ㎖-1, resulting it is lower about 140 ㎍ ㎖-1 than 429.76 ㎍ ㎖-1 of the control. Conclusion : From the above results, we may suggest that the lactic acid fermentation of mulberry leaves extracts can more enhance the hypoglycemic activities such as DNJ contents.

Background : The hypoglycemic effects of mulberry leaves extract were evaluated by comparing the abilities on glucose uptake in C2C12 myotubes and 3T3-L1 adipocyte. Glucose uptake of the extracts were identified to be enhanced by bio-conversion using cellulolytic enzyme like Viscozyme. Methods and Results : The mulberry (Morus alba L) leaves were extracted with 30% ethanol or hot water. The hypoglycemic compounds such as Moracin C and, Quercetin and 1-Deoxynojirimycin were identified from the extracts of mulberry leaves. The extracts were fermented using kinds of celluolytic enzymes, which were vicozyme, pectinase, β-glucosidase and xylanase, in order to increase the contents of hypoglycemic constituents in the extracts. The hypoglycemic effects of the fermented extracts were evaluated by comparing the abilities on glucose uptake in C2C12 myotubes and 3T3-L1 adipocyte. The extracts of mulberry leaves fermented with only Viscozyme were identified to increase glucose uptake in C2C12 myotubes and 3T3-L1 adipocyte by supplement of the concentration of 10 μM extracts, compared to insulin as control. However, bio-conversion effects by other enzymes were not shown in the treatments, suggesting hypoglycemic constituents in the extracts of mulberry leaves can be conversed to more active compounds by cellulolytic enzyme treatment like viscozyme. Conclusion : From the above results, we may suggest that the hypoglycemic constituents in mulberry leaves extracts can be conversed to more active compounds by cellulolytic enzymes.