Chae Sun Na

Neuroprotective effects of constituents of Eragrostis ferruginea against Aβ-induced toxicity in PC12 cells

A new flavonoid, 7-demethylageconyflavone A (1), and five known compounds, tricin (2), ageconyflavone A (3), corylin (4), nectandrin B (5), and 4-ketopinoresinol (6) were isolated from the aerial parts of Eragrostis ferruginea. Their structures were determined using spectroscopic techniques, including 1D- and 2D-NMR. All compounds were tested for the neuroprotective effects against amyloid beta peptide (Aβ) using PC12 cells, a major cause of the pathology of Alzheimer’s disease. Tricin (2) was found to have a neuroprotective effect with an ED50 value of 20.3 μM against Aβ-induced toxicity in PC12 cells. Ageconyflavone A (3), nectandrin B (5) and 4-ketopinoresinol (6) demonstrated moderate neuroprotective effects with ED50 values of 58.7, 44.1, and 54.8 μM, respectively.

Taxonomic Status of Endemic Plants in Korea

Disagreement among the various publications providing lists of Korean endemic plants makes confusion inevitable. We summarized the six previous reports providing comprehensive lists of endemic plants in Korea: 407 taxa in Lee (1982), 570 taxa in Paik (1994), 759 taxa in Kim (2004), 328 taxa in Korea National Arboretum (2005), 515 taxa in the Ministry of Environment (2005) and 289 taxa in Flora of Korea Editorial Committee (2007). The total number of endemic plants described in the previous reports was 970 taxa, including 89 families, 302 genera, 496 species, 3 subspecies, 218 varieties, and 253 formae. Endemic plants listed four times or more were collected to compare the data in terms of scientific names and synonyms (339 taxa in 59 families and 155 genera). If the varieties and formae were excluded, the resulting number of endemic plants was 252 taxa for the 339 purported taxa analyzed. Seven of the 155 genera analyzed were Korean endemic genera. Among the 339 taxa, the same scientific names were used in the original publications for 256 taxa (76%), while different scientific names were used for 83 taxa (24%). The four largest families were Compositae (42 taxa, 12.4%), Ranunculaceae (19 taxa, 5.6%), Rosaceae (19 taxa, 5.6%), and Scrophulariaceae (19 taxa, 5.6%). Saussurea (Compositae) had the highest number of taxa within one genus (17 taxa; 5% of total endemic taxa).

Analysis of Weed Vegetation in Vicinity of Abandoned Mines

Field study to find appropriate species for phytoremediation and phytomonitoring with higher plants was carried out at four abandoned metalliferous mines. In order to know the tolerant degree of plant resources collected at heavy metal polluted sites, soil and plants were sampled at same sites and metal concentrations were determined. Most serious heavy metal polluted in the sites was As that showed range from 29.1 to 1372.2 mg in investigated area. The dominant species were Oenothera biennis, Commelina communis, Persicaria senticosa, Conyza annuus, Artemisia princeps, and Erigeron canadensis. These species were predominant species that were proliferated in any survey area. Compared with other sites, vegetational characteristics of Dal-Seong, a mine site abandoned early in 1973, showed higher diversity index and lower dominance index. Distributions of weed species according to life cycle indicated that the proportions of perennial plants were lowered in every investigated site. Although the polluted areas were distant from each other, similarity indices among these vegetation were relatively similar. These results means the vegetations of abandoned mine areas were beginning stage of vegetational succession, and the vegetations were adversely affected by disturbance with heavy-metals and lack of water in soil.

Phytosociological Classification of Coastal Vegetation in Korea

The phytosociological study was carried out to investigate the structural characteristics of coastal vegetaion in South Korea. The vegetation data of total 102 sites were analyzed by the Zürich-Montpellier school’s method. Eleven community of coastal vegetation were recognized : Vitex rotundifolia-Rosa wichuraiana community, Calystegia soldanella community, Carex kobomugiElymus mollis community, Zoysia sinica community, Suaeda maritima community, Suaeda australis community, Suaeda glauca-Atriplex gmelinii community, Suaeda japonica community, Phragmites communis community and Calamagrostis epigeios community. Principal componant analysis (PCA) showed the similar result with phytosoiological classification.