金丝草抑菌活性成分研究

Study on antifungal constituents of Pogonatherum crinitum

为探索金丝草Pogonatherum crinitum在植物病原菌防治方面的应用前景,测定了金丝草水提取物及其乙酸乙酯、正丁醇萃取物对20种常见农作物病原真菌的抑菌活性。结果表明,2.00×10~3 mg/L的乙酸乙酯萃取物对其中8种植物病原菌的抑制率大于50%,尤其对辣椒疫霉Phytophthora capsici的抑制率高达100%。由乙酸乙酯萃取物进一步分离得到10个已知化合物,经波谱学方法鉴定其分别为1,2,4-三羟基苯(1)、1,2-二羟基-4-甲氧基苯(2)、小麦黄素-7-O-β-D-吡喃葡萄糖苷(3)、小麦黄素(4)、β-腺苷(5)、咖啡酸(6)、留兰香木脂素B(7)、木犀草素6-C-β-波依文糖-7-O-β-葡萄糖(8)、芦丁(9)及槲皮素(10),其中化合物2、3、5、7和10为从该植物中首次分离得到。孢子萌发法测定结果表明:化合物6~10对棉花立枯丝核菌Rhizoctonia solani和辣椒疫霉的孢子萌发具有较好的抑制作用,其EC_(50)值分别在18.54~103.6 mg/L和21.38~87.83 mg/L之间。

In order to explore the application prospects of Pogonatherum crinitum in the control of agricultural plant disease, the antifungal activities of the extracts of P. crinitum were tested against 20 agricultural pathogenic fungi. The results showed that these extracts had moderate activities and the inhibition rate of ethyl acetate extract（2.00×10^3 mg/L） were 50% against 8 pathogenic fungi. Especially that against P. capsici was 100%. The structure of 10 compounds were identified by ESI-MS, ^13C NMR,^1H NMR as 1,2,4-trihydroxybenzene（1）, 1,2-tidroxy-4-methoxybenzene（2）, tricin-7-O-β-Dglucopyran-oside（3）, tricin（4）, β-adenosine（5）, caffeic acid（6）, spicatolignan B（7）, luteolin-6-C-β-boivinopyranoside-7-O-β-glucopyranoside（8）, rutin（9） and quercetin（10）. Compound 2, 3, 5, 7 and 10 were obtained from P. crinitum for the first time. The antifungal activities of these compounds had been tested by method of spore germination and the result showed that compound 6-10 have significant inhibiting effect on the tested plant pathogens. The EC50 of compound 6-10 against Rhizoctonia solani and P. capsici were between 18.54-103.6 mg/L and 21.38-87.83 mg/L, respectively.