竹红菌甲素及其环糊精包合物稳定性与抑菌活性研究

摘要

Hypocrelline A (HA), a light-activated pesticide, is easily degradable and low soluble in water. We used oscillatory culture method to produce HA in an aqueous solution of hydroxypropyl-β-cyclodextrin (HA-HP-β-CD) and to compare the stability of HA in ethanol water (HA-E-W), and HA-HP-β-CD, respectively, via UV spectrophotometry. Laboratory tests showed that water, oxygen, and light could promote degradation of HA, and cyclodextrin inclusion could significantly improve the inhibition rate of Valsa mali and Botryosphaeria dothidea mycelium growth and photo-thermal stability of HA. When treatment was applied at 12000 Lx of light under 26 ℃ for 10 h, the retention rates of HA in HA-supplemented ethanol solution (HA-E), HA-E-W, and HA-HP-β-CD were 92.1%, 39.0%, and 83.6%respectively. Under a reduced oxygen condition, the HA retention rate in HA-E-W reached 99.6%. While treated under dark conditions at 26 ℃ and 50 ℃ for 10 h, the retention rates of HA in HA-E-W were 94.9% and 57.1%, respectively. The retention rate of HA in HA-HP-β-CD was 95.3%after incubation in the dark for 10 h at 50 ℃. When exposed to 12000 Lx of light at 26 ℃ for 6 d, HA-HP-β-CD at a final concentration of 10 mg/L was able to suppress 93.1%and 37.3%of the mycelium growth of V. mali and B. dothidea, respectively. At the same concentration, HA-E-W suppressed 68.7% and 25.4%of the mycelium growth of both pathogens, significantly lower than those treated with HA-HP-β-CD. Data here showed that cyclodextrin is a feasible way to produce HA.%为解决竹红菌甲素（HA）做为光活化农药易降解与难溶于水的瓶颈问题，本文通过振荡培养法制备竹红菌甲素羟丙基-β-环糊精包合物水溶液（HA-HP-β-CD），采用紫外分光光度法测定HA乙醇水溶液（HA-E-W）与HA-HP-β-CD中HA的稳定性；菌丝生长速率法测定两者抑菌率。结果表明，水、氧气和光照均能促进HA降解，环糊精包合能显著提高HA的抑菌率与光热稳定性。26℃、12000 Lx光照处理10 h，HA乙醇溶液（HA-E）、HA-E-W与HA-HP-β-CD中HA保留率分别为92.1%、39.0%与83.6%；HA-E-W去除氧气后HA保留率达99.6%。黑暗条件下26与50℃处理10 h后，HA-E-W中HA保留率分别为94.9%与57.1%，而50℃处理10 h后，HA-HP-β-CD中HA保留率可达95.3%。26℃、12000 Lx处理6 d，浓度10 mg/L的HA-HP-β-CD对苹果腐烂病菌和山核桃干腐病菌的抑菌率分别为93.1%和37.3%，均极显著高于HA-E-W对两种病原菌的抑菌率68.7%和25.4%。可见，环糊精包合是HA绿色农药制备的一种有效方式。