2,4-Dihydroxy-7-methoxy-2H-1,4-benzoxazin-3（4H）-one （DIMBOA）, the dominant benzoxazinoid hydroxamic acid in maize （Zea Mays L.）, serves as important factors of resistance against insects and microbial diseases, ...2,4-Dihydroxy-7-methoxy-2H-1,4-benzoxazin-3（4H）-one （DIMBOA）, the dominant benzoxazinoid hydroxamic acid in maize （Zea Mays L.）, serves as important factors of resistance against insects and microbial diseases, allelochemicals used in competition with other plants. In this paper, a novel and simple method for the isolation and purification of DIMBOA from maize seedlings was developed. Frozen shoots from 7-d-old maize seedlings （1 000×g） were firstly defrosted and then were directly homogenized and extracted with ethyl acetate. The macerate was allowed to stand at room temperature （25±2）°C for 1 h to allow enzymatic release of DIMBOA from DIMBOA-glucoside. Then the ethyl acetate phase was filtered, dried and evaporated to dryness. The resulting light-tan, semicrystalline residue was stored at -20°C for 24 h. Upon recrystallization from acetone-hexane, a relative higher yield （0.58 g） of pure DIMBOA crystals was obtained compared with the yield afforded by Woodward methodology （0.26 g）.展开更多
THE DIMBOA (2, 4-dihydroxy-7-methoxy-1, 4-benzoxazin-3-one), a secondary product present in corn plants, plays an important role in protecting the plant against the pest attack. DIMBOA is rich in seedlings of cereal c...THE DIMBOA (2, 4-dihydroxy-7-methoxy-1, 4-benzoxazin-3-one), a secondary product present in corn plants, plays an important role in protecting the plant against the pest attack. DIMBOA is rich in seedlings of cereal crops, especially in maize. Many investigators demonstrated a linear relationship between the DIMBOA content in plant and the resistance of the plant to pest. Feng et al. (1992) summarized that the toxicity of DIMBOA is associated展开更多
基金supported by the National Natural Science Foundation of China (30900951)
文摘2,4-Dihydroxy-7-methoxy-2H-1,4-benzoxazin-3（4H）-one （DIMBOA）, the dominant benzoxazinoid hydroxamic acid in maize （Zea Mays L.）, serves as important factors of resistance against insects and microbial diseases, allelochemicals used in competition with other plants. In this paper, a novel and simple method for the isolation and purification of DIMBOA from maize seedlings was developed. Frozen shoots from 7-d-old maize seedlings （1 000×g） were firstly defrosted and then were directly homogenized and extracted with ethyl acetate. The macerate was allowed to stand at room temperature （25±2）°C for 1 h to allow enzymatic release of DIMBOA from DIMBOA-glucoside. Then the ethyl acetate phase was filtered, dried and evaporated to dryness. The resulting light-tan, semicrystalline residue was stored at -20°C for 24 h. Upon recrystallization from acetone-hexane, a relative higher yield （0.58 g） of pure DIMBOA crystals was obtained compared with the yield afforded by Woodward methodology （0.26 g）.
文摘THE DIMBOA (2, 4-dihydroxy-7-methoxy-1, 4-benzoxazin-3-one), a secondary product present in corn plants, plays an important role in protecting the plant against the pest attack. DIMBOA is rich in seedlings of cereal crops, especially in maize. Many investigators demonstrated a linear relationship between the DIMBOA content in plant and the resistance of the plant to pest. Feng et al. (1992) summarized that the toxicity of DIMBOA is associated
