The aim of this study was to determine total phenolics (TP) content, total flavonoids (TF) level, and antioxidant activity of methanol extracts from leaf parts of 15 Vietnamese wild plants. TP content showed the highest amount in methanol extracts from Altenanthera sessilis (409.7±1.4 ppm), and followed by Eclipta prostrata (183.6±3.8 ppm) and Cassia tora (159.3±5.7 ppm). The highest TF level also was found in A. sessilis (156.3±1.7 ppm), followed by E. prostrata, and C. tora, showing similar tendency to TP. Methanol extracts of A. sessilis, E. prostrate and C. tora at 1000 ppm exhibited the highest DPPH radical scavenging activity by 94.5, 92.6 and 92.7%, respectively. The methanol extracts from A. sessilis showed the highest ABTS and nitrite scavenging activities by 97% and 92%, respectively. The highest correlation coefficient (r2) was 0.9522 between TP and TF, and followed by 0.8919 between DPPH and ABTS activities. However, polyphenols and antioxidant activities showed low correlation coefficients, ranging from r2=0.4114 to 0.4826. It was concluded that Vietnamese wild plants contain polyphenol compounds with antioxidant activities depending on plant species.

The purpose of this study is to analyze antioxidant activity and multidrug resistance reversing activity in several Korean colored soybean (Glycine max Merr.) cultivars. Antioxidant activity of methanol extracts from colored soybean cultivars was evaluated by TBARS (thiobarbituric acid reactive substances), DPPH (1, 1-diphenyl-2-picrylhydrazyl) and ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) methods. By means of TBARS, cultivar "Jeonnam #1" showed the highest activity until 7 days, and followed by "Black #1", "Jinyul" and "Black #3", showing lower activity than that of BHT (butylated hydroxytoluene). Methanol extracts of all cultivars proved that DPPH radical scavenging activity is dose-dependent. Methanol extract from cultivar "Jeonnam #1" showed highest DPPH radical scavenging activity, and followed by cultivars "Black #1". MDR (multi-drug resistance reversing) activity, however, showed the highest effect in "Black #3" and the lowest "Black #1" cultivar. These results suggest that seed colors of soybean may play an important role in antioxidant activity and MDR activity.

Common thistle contains water-soluble substances that are phytotoxic to neighboring plant species. A series of aqueous extracts from leaves, stems, roots and flowers of common thistle (Cirsium pendulum Fisch.) were assayed against alfalfa (Medicago sativa) seedlings to determine their allelopathy, and the results showed highest inhibition in the extracts from flowers and leaves, and followed by stems, and roots. The extracts at 40 g dry tissue L-1(g~;L-1) applied on filter paper in a Petri-dish significantly inhibited root growth of test plant by 87%. Methanol extracts at 100 g L-1 from leaves inhibited root growth of alfalfa and barnyardgrass (Echinochloa crus-galli) by 89 and 98%, respectively. Hexane and ethylacetate fractions of common thistle reduced alfalfa root growth more than did butanol and water fractions. Incorporation into soil with the leaf residues at 100g~;kg-1 inhibited shoot fresh weights of barnyardgrass and eclipta (Eclipta prostrate) by 88 and 58%, respectively, showing higher sensitivity in grass species. These results suggest that common thistle plants had allelopathic potential for eco-friendly vegetation management, and that especially their activities were differently exhibited depending on plant part.

Compositae plants are known to contain biologically active substances that are allelopathic to agricultural crops as well as weed species. Aqueous or methanol extracts and plant residues from leaves of Xanthium occidentale were assayed against alfalfa (Medicago sativa) to determine its allelopathic effects, and the results showed that the extracts applied onto filter paper significantly inhibited seed germination as well as root growth of alfalfa. Aqueous leaf extracts of 40g L-1 were completely inhibitory on root growth of alfalfa, while root growths of barley (Hordeum vulgare L.) and soybean (Glycine max L.) were less sensitive. Leaf residue incorporation at 100g kg-1 into soil on seedling growth of barnyard grass (Echinochloa crus-galli Beauv. var. oryzicola Ohwi) inhibited both shoot and root fresh weights of barnyard grass by 94 and 96%, respectively. Methanol extracts from BuOn and EtOAc fractions of X. occidentale reduced alfalfa root growth more than did those from hexane and water fractions. The results based on bioassay of extracts and residues show that X. occidentale had potent an allelopathic activity against other plant species.

Lettuce (Lactuca sativa L.) is known to contain water-soluble substances that improve antioxidant status due to the richness in antioxidants. Greenhouse experiment was carried out under different shading conditions during spring lettuce growing season. Shade significantly reduced shoot weight, number of leaves and chlorophyll content, while it increased shoot length of lettuce plants. The antioxidant potential of the individual fraction was in order of n-butanol 〉 ethyl acetate 〉 water 〉 n-hexane fraction, although was less than that of commonly used antioxidants, BHT and ascorbic acid. Fractions from lettuce plants dose-dependently increased DPPH free radical scavenging activity, in vitro test. By means of HPLC analysis, BuOH fraction of cultivar 'Hwahyang' (57.93 mg 100g-1) had the highest amount of antioxidant chi orogenic acid. Shading treatment increased average amount of chlorogenic acid of all cultivars in BuoH, EtOAc, hexane and water fractions by 33, 120, 144, and 58%, respectively. These results suggest that lettuce plants had potent antioxidant activity, and their activities were differently exhibited depending on cultivar and fraction.

Compositae plants are known to contain biologically active substances that are allelopathic to agricultural crops as well as weed species. Aqueous extracts from leaves of Xanthium occidentale were assayed against alfalfa (Medicago sativa) to determine their allelopathic effects, and the result showed that the extracts applied onto filter paper significantly inhibited seed germination as well as root growth of alfalfa. Untreated seeds germinated in 60h, but extract concentrations greater than 30g ~textrmL-1 delayed seed germination. The extracts significantly inhibited seed germination of alfalfa, and β -amylase activity of alfalfa and barley seeds during 24-36 hours after treatment. Aqueous extracts of 40 g ~textrmL-1 from X. occidentale were completely inhibited the hypocotyl and root growth of alfalfa. Aqueous leaf extracts showed the highest inhibitory effect and followed by root and stem extracts. Early seedling growth of both alfalfa and barnyard grass (Echinochloa crus-galli) was significantly reduced by methanol extracts. By means of high-performance liquid chromatography, chlorogenic acid and trans-cinnamic acid were quantified as the highest amounts from water and EtOAc fractions, respectively. BuOH and EtOAc fractions of X. occidentale reduced alfalfa root growth more than did hexane and water fractions. The findings of the bioassays for aqueous or methanol extracts reflected that the inhibitory effect of extract was closely related to the level of responsible allelochemicals found in plant extracts.

This study was conducted to investigate the effect of Activated charcoal (AC) for stimulating growth and productivity of Curcuma longa Linne as affected by different concentrations of AC. Growth characteristics such as plant height and leaf length were the highest with the optimum amount of activated charcoal ranged from 10 to 30%. Root growth was elongated by the addition of 30% AC with the highest rhizome length and weight.

A series of aqueous extracts and residues from leaves, stems, roots, pods and seeds of Korean black soybean (Glycine max (L.) Merr.) were assayed against alfalfa (Medicago sativa) and barnyard grass (Echinochloa crus-galli) to determine their allelopathic activities through petri-dish and greenhouse experiments, and the results showed highest inhibition in the extracts or residues from the seeds, and followed by pods. The extracts of 40g dry tissue ~textrmL-1 applied on filter paper in petri-dish bioassay significantly inhibited root growth of alfalfa, and especially extracts from seeds and pods reduced root length of alfalfa more than those from leaves, stems, or roots. Plant height, root length, shoot and root dry weights of barnyard grass were reduced significantly by residue incorporation of seeds and pods as the incorporated amount increased. These results suggest that black soybean plants had herbicidal potential, and their activities were exhibited differently depending on plant parts.

Herbicidal activity of δ -aminolevulinic acid(ALA), an intermediate for the biosynthesis of tetrapyrroles such as chlorophyll, heme, bacteriochlorophyll, and vitamin ~textrmB12 analogues, was examined to determine the variation in phytotoxic potential against different plant species as affected by different application methods. Seed-soaking treatment, ALA at low concentrations did not affect shoot and root lengths of test plants while at highest concentration reduced them by 20 to 30%. Alfalfa showed the most tolerant response to ALA in both pre- and post-emergence application, and followed by rice. When applied with pre-emergence, cotyledons of Chinese cabbage were severely bleached with 0.5 mM of ALA at 24 hrs after application, and root growth of rice, barnyard grass, and alfalfa was significantly inhibited with increasing of concentration. With post-emergence application, ALA at 2 to 4 mM reduced shoot and root growths of Chinese cabbage and barnyard grass completely. Herbicidal effects of ALA were more enhanced in the treatment combined with 2,2-dipyridyl sthan single application in barnyard grass and Chinese cabbage. The results suggest that alfalfa was the most tolerant to ALA among the tested plants, and that post-emergence application of ALA exhibited greatest photodynamic activity against tested plants.

To develop optimumal storage method of root of Bupleurum falcatum Radix grown on major cultural herbal medicine materials, root of Bupleurum falcatum Radix was stored for 10 months with different packing materials and sealing methods. The loss in dry weight as influenced by packing materials and sealing methods was the lowest at vacuum packing and followed by complete sealing methods with transparent polyethylene film. The ratio of root rot during the storage period was not significantly different between packing materials but was significantly different between sealing conditions. Conclusionally, vacuum packing and complete sealing with polyethylene film appears to be optimal for storage of Bupleurum falcatum Radix.

Most parts of alfalfa plant have been reported to contain autotoxic substances that inhibit seed germination and early seedling growth, however, the chemical(s) is not still studied much. Effect of seed leachates of 'Vernal' alfalfa (Medicago sativa L.) was evaluated for inhibition of alfalfa germination and root growth through bioassay. Alfalfa seeds were extracted in 1 L deionized water for 1 h after soaking and the leachates caused to reduce root length of alfalfa significantly as the soaking time increased. Crude seeds at 4 g LL-1 exudated autotoxins that reduce significantly root length by 34 % compared to the control, when the seeds soaked in deionized water for 24 h. However, the extracts did not affect final germination as well as speed of germination. Extracts from ground seeds significantly reduced speed of germination (GT 50) and root length. The results indicate that release of autotoxic substances from seeds during seed imbibition was increased with increase of soaking time and seed amount, and that autotoxicity was more occurred in ground seeds than in crude seeds.

Umbelliferae medicinal crops have low germination under natural condition. Special objective of this study is to investigate morphological characteristics of seeds and effects of environmental factors such as light and temperature on their germination and seedling growth in Umbelliferae plants, using them as oriental medicine materials. Fruits of Umbelliferae are bi-partite type and form 2 seeds. Their oil canals and funiculus or carpaphore has apparently specific shape. Seed shape of Buplerum falcatum, Ligusticum acutilobum and Foeniculum vulgare are oblong, Ledeboutiella seseloides, Angelica dahurica, Angelica gigas elliptic, and Ostericum koreanum ovate. Color of seed coats varied from yellow to dark brown. Seed size was 3.2 to 6.9 mm in length, 1.7 to 4.9 mm in width. One thousand-seed weight of Buplerum falcatum was lowest(at 1,660 mg) and Ledebouriella seseloides and Angelica gigas were relatively highest(at 3,970 mg) having larger size than any others. Optimum temperatures for seed germination and seedling growth ranged from 20 to 25℃ and especially temperature at 25℃ improved seed germinations of Ledebouriella seseloides, Angelica dahurica and Ligusticum acutilobum regardless of light condition.