2021年4月23日 星期五
甘草根中黄酮类化合物的提取、分离与 衍生化及其抑菌活性研究
Extraction, isolation, and derivatization of flavonoids from root of Glycyrrhiza uralensis and study on their anti-microbial activities
2020年 第29卷 第6期 页码[32-41]
摘要

采用多重柱层析和重结晶的方法从甘草(Glycyrrhiza uralensis Fisch.)根中提取和分离6个黄酮类化合物,并通过结构修饰获得3个乙酰化衍生物,然后使用核磁共振和旋光技术进行结构鉴定;在此基础上,分别采用菌丝生长速率法和比浊法测定9个化合物在10 μg·mL-1时对植物病原真菌和细菌的抑制率,并进一步测定了具有抑菌活性化合物的EC50(有效中浓度)和EC90(抑制率90%时的化合物浓度)值。结果表明:甘草根中6个黄酮类化合物及3个乙酰化衍生物分别为4′-O-甲基光甘草定、hispaglabridin B、光甘草定、甘草素、异甘草素、甘草苷、4,4′-O-二乙酰基异甘草素、4-O-乙酰基异甘草素和4′-O-乙酰基甘草素。在10 μg·mL-1时,4′-O-甲基光甘草定、hispaglabridin B和光甘草定对大部分供试病原菌的抑制率较高,异甘草素对水稻白叶枯病菌(Xanthomonas oryzae pv. oryzae)的抑制率达到76.25%,而4,4′-O-二乙酰基异甘草素和4-O-乙酰基异甘草素对部分病原菌的抑制率高于30.00%。4′-O-甲基光甘草定对油菜菌核病菌(Sclerotinia sclerotiorum)、黄瓜灰霉病菌(Botrytis cinerea)和稻瘟病菌(Magnaporthe oryzae)的EC50值均小于10.00 μg·mL-1,对黄瓜灰霉病菌的EC50和EC90值显著(P<0.05)低于对照药剂甲基硫菌灵,对水稻纹枯病菌(Rhizoctonia solani)的EC50和EC90值与甲基硫菌灵总体上无显著差异。Hispaglabridin B对黄瓜灰霉病菌的EC50和EC90值显著低于甲基硫菌灵。光甘草定的抑菌活性最强,除了对枸杞炭疽病菌(Colletotrichum gloeosporioides)的EC50值为48.90 μg·mL-1外,对其他供试病原菌的EC50值均小于10.00 μg·mL-1,并且对水稻纹枯病菌、香蕉枯萎病菌(Fusarium oxysporum)、黄瓜灰霉病菌和小麦赤霉病菌(Fusarium graminearum)的EC50和EC90值总体上显著低于甲基硫菌灵。异甘草素对水稻白叶枯病菌的EC50值仅为2.98 μg·mL-1,与对照药剂噻枯唑无显著差异。综上所述,4′-O-甲基光甘草定、hispaglabridin B和光甘草定具有广谱抑菌活性,可作为新型生物农药先导化合物进行开发;异甘草素对水稻白叶枯病菌具有较高的抑菌活性,可作为先导化合物开发细菌病害防治药剂。

Abstract

 Six flavonoids were extracted and isolated from root of Glycyrrhiza uralensis Fisch. by using multi-column chromatography and recrystallization methods, three acetyl derivatives were obtained by structural modification, and then nuclear magnetic resonance and optical rotation technology were employed to confirm their structures; on the basis, inhibition rates of nine compounds at 10 μg·mL-1 against plant-pathogenic fungi and bacteria were determined by using mycelial growth rate method and turbidity method, and EC50(median effective concentration) and EC90(compound concentration at the inhibition rate of 90%) values of compounds with anti-microbial activities were further assayed. The results show that six flavonoids isolated from root of G. uralensis and three acetyl derivatives are 4′-O-methylglabridin, hispaglabridin B, glabridin, liquiritigenin, isoliquiritigenin, liquiritin, 4,4′-O-diacetylisoliquiritigenin, 4-O-acetylisoliquiritigenin, and 4′-O-acetylliquiritigenin. At 10 μg·mL-1, 4′-O-methylglabridin, hispaglabridin B, and glabridin exhibit high inhibition rates against most test pathogens, inhibition rate of isoliquiritigenin against Xanthomonas oryzae pv. oryzae reaches 76.25%, while those of 4,4′-O-diacetylisoliquiritigenin and 4-O-acetylisoliquiritigenin against some pathogens are greater than 30.00%. The EC50 values of 4′-O-methylglabridin against Sclerotinia sclerotiorum, Botrytis cinerea, and Magnaporthe oryzae are all smaller than 10.00 μg·mL-1, and its EC50 and EC90 values against B. cinerea are significantly (P<0.05) lower than those of control fungicide thiophanate-methyl, but those against Rhizoctonia solani are not significantly different from those of thiophanate-methyl in general. The EC50 and EC90 values of hispaglabridin B against B. cinerea are significantly lower than those of thiophanate-methyl. The anti-microbial activity of glabridin is the strongest, and except for the EC50 value against Colletotrichum gloeosporioides, which is 48.90 μg·mL-1, the EC50 values against other test pathogens are all smaller than 10.00 μg·mL-1, meanwhile its EC50 and EC90 values against R. solani, Fusarium oxysporum, B. cinerea, and Fusarium graminearum are generally significantly lower than those of thiophanate-methyl. The EC50 value of isoliquiritigenin against X. oryzae pv. oryzae is only 2.98 μg·mL-1, which is not significantly different from that of control bactericide bismerthiazol. It is suggested that 4′-O-methylglabridin, hispaglabridin B, and glabridin possess broad-spectrum anti-microbial activities, and can be developed as leads of novel bio-pesticide; isoliquiritigenin possesses potent anti-microbial activity against X. oryzae pv. oryzae, and can be used as a lead for developing control agents against bacterial disease.

关键词甘草; 黄酮类化合物; 衍生物; 植物病原菌; 抑制率; 室内毒力
Key wordsGlycyrrhiza uralensis Fisch.; flavonoids; derivatives; phytopathogens; inhibition rate; laboratory toxicity
作者徐曙1, 赵兴增1, 周倩1, 陈虞超2, 李林蔚1, 郭生虎2
所在单位1. 江苏省中国科学院植物研究所(南京中山植物园), 江苏 南京 10014; 2. 宁夏农林科学院农业生物技术研究中心, 宁夏 银川 750002
点击量276
基金项目宁夏农林科学院对外科技合作专项(DW-X-2018009); 2019年医疗服务与保障能力提升补助资金(中医药事业传承与发展部分)“全国中药资源普查项目”(财社〔2019〕39号)