杨梅叶抑菌活性成分初步分离与鉴定

用石油醚、氯仿、乙酸乙酯和正丁醇分别对杨梅叶甲醇提取物进行了萃取,得不同萃取相。测定了其对番茄灰霉病菌Botrytis cinerea、番茄早疫病菌Alternaria solani、水稻立枯丝核Rhizoctonia solani、小麦禾谷镰刀菌Fusarium graminearum、 黄瓜炭疽病菌Colletotrichum lagenarium、玉米大斑病菌Setosphaeria turcica等植物病原菌的抑菌活性。结果表明,乙酸乙酯相和正丁醇相的抑菌活性较好。对乙酸乙酯相进一步分离得到7个化合物,经电喷雾质谱(ESI-MS)、核磁共振氢谱(1H NMR)和碳谱(13C NMR)鉴定其分别为已知化合物山楂酸( 1 )、3-O-反-对-香豆酰基马斯里酸( 2 )、3-O-没食子酰二氢杨梅素( 3 )、斛皮素-7-O-鼠李糖甙( 4 )、杨梅素3-O-鼠李糖甙( 5 )、杨梅素-3-O-鼠李糖(3-O-没食子酰)甙( 6 )和杨梅素-3-O-鼠李糖(2-O-没食子酰)甙( 7 )。孢子萌发法测定结果表明,化合物 3~6 对番茄灰霉病菌和玉米大斑病菌的孢子萌发具有较好的抑制作用,EC50值分别在3.44~4.59 mg/L和8.85~11.6 mg/L之间。

Isolation and identification of antifungal constituents from the leaf of Myrica rubra

Methanol extract of the leaves of Myrica rubra was further partitioned with petroleum ether,chloroform,ethyl acetate and n-butanol respectively and obtained four crude extracts.Antifungal activity of the four crude extracts was tested .It showed that ethyl acetate and n-butanol extract had higher activity.Their structures were identified by ESI-MS,¹H NMR and ¹³C NMR as maslinic acid( 1 ),3-O-trans-p-coumaroyl maslinic acid( 2 ),3-O-galloyl-dihydromyricetin( 3 ),quercetin-7-O-rhamonside( 4 ),myricetin-3-O-rhamnoside( 5 ),myricetin-3-O-rhamnoside(3-O-galloyl)( 6 ),myricetin-3-O- rhamnoside(2-O-galloyl)( 7 ).The inhibition effects of compound 3,4,5 and 6 had been tested by method of spore germination and the result showed that all the 4 compounds have strong inhibiting effect on the tested plant pathogens.Botrytis cinerea and Setosphaeria turcica which LC₅₀ velues were between 3.44-4.59 mg/L and 8.85-11.6 mg/L,respectively.