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10μg·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10μg·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10.00μg·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48.90μg·mL^-1外,对其他供试病原菌的EC50值均小于10.00μg·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2.98μg·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。
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 10μg·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 10μg·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 10.00μg·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 48.90μg·mL^-1,the EC50 values against other test pathogens are all smaller than 10.00μg·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 2.98μg·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.
作者
徐曙
赵兴增
周倩
陈虞超
李林蔚
郭生虎
XU Shu;ZHAO Xingzeng;ZHOU Qian;CHEN Yuchao;LI Linwei;GUO Shenghu(Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China;Agricultural Biotechnology Center, Ningxia Academy of Agricultural and Forestry Sciences, Yinchuan 750002, China)
出处
《植物资源与环境学报》
CAS
CSCD
北大核心
2020年第6期32-41,共10页
Journal of Plant Resources and Environment
基金
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)。
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
Glycyrrhiza uralensis Fisch.
flavonoids
derivatives
phytopathogens
inhibition rate
laboratory toxicity
