The antimicrobial effect of each fraction after fractionation of an ethanol extract of leaf mustard was examined in terms of nucleic acid, chloroform, ethylacetate, and butanol. The ethylacetate fraction, which showed the strongest level of antimicrobial effect among the different ethanol extract fractions of leaf mustard, was isolated and purified using silica gel column chromatography and HPLC, respectively, to obtain a single antimicrobial substance called KLM-1. The antimicrobial effect of this substance was 10 times higher than that of the ethylacetate fraction. A further study is on the way to confirm the structure of the antimicrobial substance KLM-1 through LC/Mass and NMR.

As part of developing natural food preservatives, the antimicrobial effect of ethanol and water extracts from the Cruciferous vegetable was examined Korean traditional Brassica juncea Coss. was used widely as an ingredient of Kimchi, a natural flavoring and spice for a long time. Antimicrobial activities were examined against 15 microorganisms which were food-born pathogens and/or food poisioning microorganisms and food-related bacteria and yeasts. Ethanol extract from leaf mustard showed an antimicrobial effect in most of the strains used in the present study. The lowest minimum inhibitory concentration (MIC) were seen in Bacillus subtilis and Bacillus natto at 10 mg/ml. MIC of water extract was 40-60 mg/ml for bacteria and yeast. Antimicrobial activity of the ethanol extract was not disappeared by the heating at 121℃ for 15 min and not affected by pH.

To study the effects of metal ions on the activity of anti-oxidase enzymes, the activity of superoxide dismutase (SOD) and peroxidase (POD) and isozyme patterns of Brassica juncea have been studied after treating with CD, Cu, Zn, and Al. The activity of SOD after treating with metal ions was higher than that of untreated control. SOD activity in leaves increased by treatment of 50 ppm of Zn and 500 ppm of Al. POD in stems gave highest activity after treating with 500 ppm of Cu. When the activity was compared by plant parts, lowest POD activity was observed in leaves in which protein content was higher than other tissues. When the activity was expressed as percentage of control, SOD activity was increased after treating with metal ions. SOD activity in leaves and roots of metal treated plant was significantly increased under the metal ions stress conditions. In the roots of 50 ppm of Zn treated plant, SOD activity was extremly high. POD activity was inhibited with Cd and Zn treatment in all parts of the plant. However, in leaves and stems, there was marked increase in activity after treating with Cu. The patterns of SOD isozyme after metal treatment show that two bands were stained in all metal ion treated and that no new band appeared. POD isozyme band intensity resulting from the treatment of metal ions was in order of roots > stems > leaves, but there was no significant difference.

개자의 육종적 개량 가능성과 재배적 개선 가능성을 검토하기 위하여 수집된 5개품종들을 파종기를 달리하여 1980~82년 까지 3 개년에 걸쳐 시험한 결과는 다음과 같다. 1. 공시품종간에 추태기는 제주종, 서울종, 일본종이 빠르고 영산포종과 수원종은 늦은 편이었으며 성숙기는 수원종이 가장 늦었다. 2 . 초장은 수원종이 가장 짧았으나 협당종실수는 가장 많았으며 분지수는 서울종, 영산포종이 많은 반면 입중, 협장 및 중에 있어서는 품종간 차이가 인정되지 않았으며 종실수량은 서울종이 248kg/10a로 높았다. 3. 유분함량은 품종간 28.8 ~32.1%의 변이를 보였으며 황갈색종피인 서울종. 영산포종. 제주종이 높은 경향이었고 탈지박중의 Glucosinolate 함량은 전체적으로 높은 경향이었다. 4. 파종기가 지연됨에 따라 추태, 개화가 지연되며 초장, 총 분지수, 수당협수가 감소하는 경향인데 추태는 수원종, 제주종, 일본종이 개화기는 제주종이 초장은 서울종, 제주종이 수당협수에서는 서울종, 수원종. 일본종이 그리고 협당입수에서는 제주종이 민감한 반응을 나타냈다. 5. 파종기 지연에 따른 입중, 중. 협장 및 유분함량이나 지방산조성 변이는 인정되지 않았다. 6 경노계수 분석 결과 수량에 대한 직접효과가 큰 형질은 총 분지수, 개화기, 수장이었고 간접효과가 큰 형질은 수장을 통한 초장이었던 반면 파종기가 지연됨에 따라 초장이나 수장 보다 개화기나 결실비율의 직접효과가 뚜렷해지는 경향이었다.