title: Main Ustilaginoidins and Their Distribution in Rice False Smut Balls.
abstract: Rice false smut has become an increasingly serious fungal disease in rice (Oryza sativa L.) production worldwide. Ustilaginoidins are bis-naphtho-γ-pyrone mycotoxins previously isolated from the rice false smut balls (FSBs) infected by the pathogen Villosiclava virens in rice spikelets on panicles. To investigate the main ustilaginoidins and their distribution in rice FSBs, five main bis-naphtho-γ-pyrones, namely ustilaginoidins A (1), G (2), B (3), I (4) and C (5), were isolated and identified by NMR and high-resolution mass spectrometry as well as by comparison with the data in the literature. The rice FSBs at early, middle and late maturity stages were divided into their different parts and the contents of five main ustilaginoidins for each part were determined by HPLC analysis. The results revealed that the highest levels of ustilaginoidins were in late stage rice FSBs, followed by those at middle stage. Most ustilaginoidins, 96.4% of the total quantity, were distributed in the middle layer at early stage. However, ustilaginoidins were mainly distributed in the outer and middle layers at middle and late stages. Small amounts of ustilaginoidins A (1) and G (2) were found in the inner part of rice FSBs at each maturity stage. The contents of ustilaginoidins A (1) and G (2) without hydroxymethyl groups at C-2 and C-2' of the γ-pyrone rings in rice FSBs were relatively high at early stage, while the contents of ustilaginoidins B (3), I (4), and C (5) with hydroxymethyl groups at C-2 or C-2' were relatively high at late stage.
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China. mengjiajiax@163.com.
authors.forename: Jiajia
authors.initials: J
authors.lastname: Meng
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China. sunweibo.1001@163.com.
authors.forename: Weibo
authors.initials: W
authors.lastname: Sun
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China. maoziling2011@163.com.
authors.forename: Ziling
authors.initials: Z
authors.lastname: Mao
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China. cauxudan@163.com.
authors.forename: Dan
authors.initials: D
authors.lastname: Xu
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China. wangxiaohan99@126.com.
authors.forename: Xiaohan
authors.initials: X
authors.lastname: Wang
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China. shiqionglu@126.com.
authors.forename: Shiqiong
authors.initials: S
authors.lastname: Lu
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China. dwlai@cau.edu.cn.
authors.forename: Daowan
authors.initials: D
authors.lastname: Lai
authors.affiliation: Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Processing, Ministry of Agriculture, Beijing 100193, China. liuyang01@caas.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China. lgzhou@cau.edu.cn.
authors.forename: Ligang
authors.initials: L
authors.lastname: Zhou
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China. zhanggzh@cau.edu.cn.
authors.forename: Guozhen
authors.initials: G
authors.lastname: Zhang
mesh_terms: D001487:Basidiomycota / Q000302:isolation & purification / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D015394:Molecular Structure; D009183:Mycotoxins / Q000302:isolation & purification*; D009281:Naphthalenes / Q000302:isolation & purification*; D012275:Oryza / Q000254:growth & development / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology*; D011753:Pyrones / Q000302:isolation & purification*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D009183:Mycotoxins; D009281:Naphthalenes; D011753:Pyrones
keywords: HPLC; Ustilaginoidea virens; Villosiclava virens; mycotoxin; phytotoxin; rice false smut balls; ustilaginoidins