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 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.