This study was carried out to investigate the antioxidant activities and the contents of antioxidant compounds in extracts derived from 23 medicinal crops. Dried plant materials were extracted by 80% methanol and the extracts were used to experiment. The levels of total phenolic compounds were much higher in Oenothera biennis, Houttuynia cordata, Cedrela sinensis, Rhus javanica, Artemisia annua, Reynoutria sachalinensis, and Dendropanax morbifera compared with other crops. On the other hand, the total phenolic compound levels in Carthamus tinctorius, Polygonum multiflorus, Ginko biloba, Solanum nigrum, and Saposhnikovia divaricata were relatively low. The total flavonoid contents were highest in H. cordata, followed by D. morbifera, A. annua, A. continentalis and O. biennis. DPPH activity was significantly higher in A. annua, R. javanica, C. sinensis, D. morbifera and O. biennis, and ABTS activity was significantly higher in R. javanica, C. sinensis, O. biennis, R. sachalinensis, A. annua, and D. morbifera than other plants. These results suggest that O. biennis, A. annua, R. javanica, D. morbifera, and R. sachalinensis can be utilized as food additives and natural antioxidants due to their strong antioxidant activity.

Background: This study was conducted to investigate the effects of fertilization with the application of mixed organic matter after cultivating green manure crops on the growth and saponin content of Codonopsis lanceolata Trautv. Methods and Results: Five type of cultivation of green manure crops were done: hairy vetch as a single seedling crop (HV), hairy vetch and rye as a mixture of seedling (HV/R), additional fertilization with mixed organic matter after cultivation of a seedling mixture (HV/R/MO), chemical fertilizer (CF), and a non-treated control (NT). The total nitrogen content was the highest in the HV/R/ MO treatment, followed by the HV, CF, HV/R and NT treatments, respectively. Nitrogen fixation was higher in the single seedling treatment with hairy vetch (HV) than in the treatment with a mixture of hairy vetch and rye seedling (HV/R). Moreover, the growth of C. lanceolata was greatly increased by the application of additional fertilizer after treatment with the mixture of hairy vetch and rye seedlings. The HV/R/MO treatment produced the highest total lancemaside content among the treatments, followed by HV, HV/ R, CF, and NT, respectively. Conclusions: It was verified that C. lanceolata experienced superior growth with the application of mixed organic matter as additional fertilizer after the cultivation of green manure crops, and the content of its major saponins, lancemasides were also increased by this treatment.

Background : Codonopsis lanceolata has been used in traditional medicines, as its roots contain several kinds of triterpenoid saponin with high medicinal values. This study was conducted to select an advanced extraction method in C. lanceolata root. Methods and Results : Four extraction methods including 70% MeOH reflux and solvent fraction (n-hexane, ethyl acetate, butanol, water), water saturated butanol reflux, boiling water, and ultrasonication (70% MeOH) were investigated for the determination of major lancemasides. The total contents of lancemasides were the highest of 2.80 ㎎/g in ultrasonication, followed by boiling water, MeOH reflux, and water saturated butanol reflux extraction, in that order. Lancemaseide A was the most abundant saponin in all treatments, followed by lancemaside G, aster saponin, lancemaside B, in that order. The content of lancemaside B was very low compared to lancemaside A. Although four types of saponins were confirmed in this study, the others saponin such as foetidissimoside A could not be quantified due to very low content. Ultrasonication was evaluated as optimal extraction method and further studies were conducted to determine the optimal condition. The result compared to dry methods of sample [freeze-drying and shade dry (< 60℃)] before ultrasonication was superior shade dry to freeze-drying. The extract time and temperature were the best in 2 hr, 64℃ treatment, respectively, although there was no significant statically. Conclusion : The ultrasonication method was evaluated as relatively simpler and more efficient method due to short extraction time, small solvent consumption relative to conventional reflux method.

Background : Stevia extracts were reported to contain steviol glycosides like stevioside and rebaudioside A, as well as various polyphenol compounds. However, there are many difference in researchers with extract methods, considering components and antioxidant activity. This study was conducted to select optimum extraction method based on reported methods by measuring the natural sweeteners contents, analyzing antioxidant materials and activity according to extraction methods. Method and Results : Stevia leaves were extracted through vacuum extraction, hot water extraction, soxhlet extraction, high temperature and pressure extraction and ultrasonic extraction to identify the high extraction efficiency. Extraction yield was high in order of hot water extraction, soxhlet extraction, high temperature and pressure extraction and ultrasonic extraction except for vacuum extraction and contents of rebauduoside A and stevioside in stevia leaves was highest in high temperature and pressure extraction followed by vacuum extraction, soxhlet extraction, hot water extraction and ultrasonic extraction. Also, total phenolic contents and flavonoid contents were highest in high pressure extraction and vacuum extraction according to extraction methods. But DPPH radical scavenging activity was highest in ultrasonic extraction and tended to be rather low in high temperature and pressure extraction (ultrasonic extraction > hot water extraction > high pressure extraction > soxlet extraction > vacuum extraction) and there wa no difference in ABTS radical scavenging activity among extraction methods. Conclusion : The high temperature and pressure extraction is considered to be a suitable method for extracting stevia leaves because it showed high extraction yield and had high contents of rebaudioside A, stevioside, total phenolic contents and flavonoid contents.

Background : This study was carried out to select the medicinal crop having the superior antimicrobial activity against 5 microorganisms among 20 medicinal crops. Methods and Results : Dried plants were extracted by methanol. The extracts of each plant were evaporated under vacuum. The extracts were absorbed into 50㎕ of each extracts on paper disk and diameter of clear zone was confirmed around the colony. The results showed that diameter of the clear zone against Escherichia coli was the widest in Rhus javanica(R. javanica, 16mm), followed by Evening primrose(14.5mm), Chinaberry(13mm) and Giant knotweed(11mm). Also, diameter of the clear zone against Vibrio parahaemolyticu was the widest in R. javanica(26mm), followed by Evening primrose(21mm), chrysanthemum flower(19mm), Chinese pepper(16.5mm), Chidii rhizoma(11.5mm), Curly dock(11.5mm), Comfrey(11mm), Black nightshade(11mm) and Mustard(10mm). Likewise, diameter of the clear zone aginast Proteus mirabilis was the widest in R. javanica(11.5mm), followed by Chinaberry(11mm). Specially, diameter of the clear zone against Bacillus subtilis and Staphylococcus aureus was identified only in R. javanica(12mm and 11mm, respectively). Therefore, R. javanica showed the best excellent antimicrobial activity among 20 medicinal crops. Total phenolic and flavonoid contents of R. javanica were 2,725mg/100g and 30.2mg/100g respectively. DPPH and ABTS activity of R. javanica were 92.6% and 98.4%, respectively. Conclusion : These results suggest that R. javanica can be utilized as natural food additives and antioxidant materials because of its powerful antimicrobial action and the high antioxidant activity.

Background: This study determined the effects of mulching, an environment friendly organic cultivation method, on antioxidant compound contents and growth in Codonopsis lanceolata, commonly known as Deodeok. Methods and Results: C. lanceolata was treated by mulching with several different methods (a non-woven fabric, biodegradable film, or rice husks) and also treated with hand weeding. A non-treatment plot was used as a control. The growth and levels of weed control in C. lanceolata were better in plants cultivated under mulching treatments (non-woven fabric, biodegradable film, and rice husks) than in those under non-mulching treatments (hand weeding and non-treatment). The contents of antioxidant compounds, such as total flavonoids, phenolics, and anthocyanins, were highest under the biodegradable film treatment, followed by the nonwoven fabric treatment, rice husks treatment hand weeding, and non-treatment. There were identifiable differences in DPPH and ABTS activity in comparison to antioxidant compound content by solvent fractions. Mulching treatments resulted in higher DPPH scavenging activity in water and ethyl ether fractions and ABTS scavenging activity in n-butanol fractions than in other fractions, as opposed to hand weeding and non-treatment groups, although total activity of DPPH and ABTS did not increase with mulching treatments. Conclusions: Mulching C. lanceolata with biodegradable film and non-woven fabric is an effective method for improving plant growth and inhibiting the occurrence of weeds as well as for increasing antioxidant compound content and altering antioxidant activity.

Background : This study was conducted to determine the effects of mulching, an environmentally friendly organic cultivation method, on antioxidant compounds and growth in Codonopsis lanceolata. Methods and Results : C. lanceolata was treated by mulching with a non-woven fabric, biodegradable film, or rice husks, as well as hand weeding, and non-treatment. The growth and levels of weed control in C. lanceolata were better in plants cultivated under mulching treatments (non-woven fabric, biodegradable film, and rice husks) than under non-mulching treatments (hand weeding, non-treatment). The contents of antioxidant compounds, such as total flavonoids, phenolics, and anthocyanin, were highest under biodegradable film treatment, followed by non-woven fabric treatment, rice husks treatment, hand weeding, and non-treatment. DPPH and ABTS activity were able to identify to have differences their activity in comparison to antioxidant compounds content by solvent fractions. Mulching treatments produced a higher activity in water and ethyl ether fractions for DPPH scavenging activity and in n-butanol fractions for ABTS scavenging activity compared to other fractions, although total activity of DPPH and ABTS were not increased with mulching treatments. Conclusion : Mulching C. lanceolata with biodegradable film and non-woven fabric is an effective method for improving plant growth and inhibiting the occurrence of weeds as well as increasing antioxidant compound content and changing of antioxidant activity.

Background : This study was carried out to investigate the antioxidant activities and the contents of antioxidant compounds in extracts derived from 24 medicinal crops. Methods and Results : Dried plant materials were extracted by methanol. The extracts of each plant were evaporated under vacuum and stored in deep freeze at -20℃ until use. The levels of total phenolic compounds were much higher in Evening primrose, Houttuynia cordata, Chinaberry, Sumac, Gaeddongssuk, Giant knotweed and Dendropanax morbifera compared with other crops. On the other hand, the total phenolic compound levels in Safflower, Fleeceflower root, Gingko, Black nightshade, Saposhinikovia root, and Maize woody pith were relatively low. The total flavonoid contents were highest in Houttuynia cordata, followed byDendropanax morbifera, Gaeddongssuk, Aralia cordata and Evening primrose. DPPH activity was significantly higher in Gaeddongssuk, Sumac, Chinaberry, Dendropanax morbifera and Evening primrose, and ABTS activity was significantly higer in Sumac, Chinaberry, Evening primrose, Giant knotweed, Gaeddongssuk and Dendropanax morbifera than other plants. The antioxidant activities dertermined in all assays positively correlated with the total phenolic compoubds (0.619≤ r ≤0.895) and flavonoid contents (0.488≤ r ≤0.619) as well as among themselves (r=0.900). Conclusion : These results suggest that Evening primrose, Gaedongssuk, Sumac, Dendropanax morbifera, and Giant knotweed can be utilized as food additives and natural antioxidants due to their strong antioxidant activity.