Determination and Analysis of Ustiloxins A and B by LC-ESI-MS and HPLC in False Smut Balls of Rice

Tijiang Shan,Mingan Wang,Shan Gao,Wenxian Sun,Shu Wang,Hao Liu,Ligang Zhou,Zhiyi Chen,Weibo Sun,Shiqiong Lu

doi:10.3390/ijms130911275

Abstract

Ustiloxins are cyclopeptide mycotoxins produced by the pathogenic fungus Villosiclava virens of rice false smut. Ustiloxins A and B as two main mycotoxins were determined conveniently by LC-ESI-MS in the water extract from rice false smut balls which were mostly composed of the chlamydospores and mycelia of the pathogen. Both ustiloxins A and B in the water extract were also quantitatively analyzed by HPLC. This is the first report on the determination and analysis of ustiloxins A and B simultaneously by LC-ESI-MS and HPLC in false smut balls of rice.

Highlights

Ustiloxins are cyclopeptide mycotoxins containing a 13-membered cyclic core structure produced by the pathogenic fungus Villosiclava virens (Nakata) Tanaka & Tanaka [1,2,3,4] of rice false smut which is an emerging and increasingly significant disease in most rice (Oryza sativa L.) producing countries (i.e., China, India, Burma, and Japan) [5,6]
The accuracy of the method was determined by analyzing the mixtures which were obtained by adding known amounts of standard ustiloxins A and B to the rice false smut balls (200 mg) in which the contents of ustiloxins A and B were known
In this study ustiloxins A and B as the two main mycotoxins were determined conveniently by LC-ESI-MS in the water extract from rice false smut balls. Both ustiloxins A and B in rice false smut balls were quantitatively analyzed by high-performance liquid chromatography (HPLC)-UV

Summary

Introduction

Ustiloxins are cyclopeptide mycotoxins containing a 13-membered cyclic core structure produced by the pathogenic fungus Villosiclava virens (Nakata) Tanaka & Tanaka (anamorph: Ustilaginoidea virens Takahashi) [1,2,3,4] of rice false smut which is an emerging and increasingly significant disease in most rice (Oryza sativa L.) producing countries (i.e., China, India, Burma, and Japan) [5,6]. Nakamura et al reported that both ustiloxin A and the crude fraction obtained from the water extract of rice false smut balls caused liver and kidney damage in mice [8]. These findings indicate that both false smut balls and false smut pathogen-infected rice food and forage create concerns for food and feed safety. In order to detect ustiloxins in samples, only one report has been published on ustiloxin A analysis by HPLC in forage rice [9] The purpose of this investigation was to seek practical methods for isolating, analyzing and determining the main ustiloxins in a variety of samples (i.e., false smut balls, mycelia, grains, forage rice, and their products)

Methods

Results

Conclusion