苦参生物碱抑菌生物活性测定

以葡萄白腐病菌等19种病菌为供试靶标，测定了3%苦参碱水剂和苦参碱、氧化苦参碱、槐果碱、野靛碱的抑菌活性。离体试验结果表明：苦参生物碱具有一定的抑菌活性，当浓度为100mg/L时，3％苦参碱水剂的抑菌活性可达80％以上，对供试的病菌其EC50为28～48mg/L。苦参碱、氧化苦参碱、槐果碱和野靛碱具有不同的抑菌活性，4种生物碱对黄瓜黑星病菌、苹果轮纹病菌、葡萄白腐病菌和番茄灰霉病菌几乎没有抑菌活性，对其它病菌，氧化苦参碱的抑菌活性大多高于其它3种生物碱；野靛碱的抑菌活性最低，对各病菌的抑菌率均未超过10％。室内活体抑菌试验结果表明当剂量为800mg/L时，各药剂对水稻纹枯病病菌和小麦白粉病病菌均没有抑制作用，3％苦参碱水剂、氧化苦参碱和野靛碱对黄瓜灰霉病表现出了抑制作用，3%苦参碱水剂、苦参碱和槐果碱具有较高的抑制黄瓜霜霉病病菌的活性，防效达80％以上，野靛碱对其也有一定的抑制作用。

Antibiotic Activity of Alkaloids from Sophora flavescens

Antibiotic activity of a 3% soluble matrine formulation, matrine, oxymatrine, sophocarpine, and cytisine were determined on 19 pathogens including Coniella diplodiella. In vitro test results at 100 mg/L were as follows: alkaloids from Sophora flavescens had antibiotic activity; the 3% matrine formulation provided >80% inhibition, with an EC50 between 28 and 48 mg/L; antibiotic activities of matrine, oxymatrine, sophocarpine, and cytisine varied, showing little activity against Cladosporium cucumerinum, Physalospora piricola, Coniella diplodiella, and Botrytis cinerea; oxymatrine had higher activity than matrine, sophocarine, and cytosine against most of the other pathogens; cytisine had the lowest activity, providing less than 10% inhibition of all pathogens. Results of greenhouse plant disease tests at 800 mg/L were as follows: none of the alkaloids inhibited Erysiphe graminis on rice and Rhizoctonia solani on wheat; formulated 3% matrine, oxymatrine, and cytisine showed some inhibition of Botrytis cinerea on cucumber; formulated 3% matrine, matrine, and sophocarpine provided relatively high inhibitory activity of Pseudoperonospora cubensis on cucumber, while cytisine also showed some effect.