Katsumata Shun, Hamana Kazuho, Horie Kiyotaka, Toshima Hiroaki, Hasegawa Morifumi
College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami, Ibaraki, 300-0393, Japan.
United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan.
Chem Biodivers. 2017 Feb;14(2). doi: 10.1002/cbdv.201600240. Epub 2017 Jan 21.
Sakuranetin (1) is a flavanone phytoalexin that has been reported to play an important role in disease resistance in rice plants. The rice blast fungus Pyricularia oryzae (syn. Magnaporthe oryzae) has been reported to metabolize 1 to lower its antifungal activity. Here, two flavanones, sternbin (2) and naringenin (3), were identified as metabolites of 1 in P. oryzae suspension culture by liquid chromatography tandem mass spectrometry (LC/MS/MS). The inhibition of 1, 2, and 3 on P. oryzae mycelial growth were 45%, 19%, and 19%, respectively, at a concentration of 100 μm. Thus, 2 and 3 are detoxified metabolites of 1 by P. oryzae.
樱黄素（1）是一种黄烷酮类植保素，据报道在水稻植株的抗病性中发挥重要作用。据报道，稻瘟病菌（Pyricularia oryzae，同义词：Magnaporthe oryzae）可将1代谢以降低其抗真菌活性。在此，通过液相色谱串联质谱法（LC/MS/MS）在稻瘟病菌悬浮培养物中鉴定出两种黄烷酮，即司替宾（2）和柚皮素（3），它们是1的代谢产物。在浓度为100μm时，1、2和3对稻瘟病菌菌丝生长的抑制率分别为45%、19%和19%。因此，2和3是稻瘟病菌对1的解毒代谢产物。
