TY - JOUR
T1 - Yellow pigments used in rapid identification of aflatoxin-producing Aspergillus strains are anthraquinones associated with the aflatoxin biosynthetic pathway
AU - Shier, W. Thomas
AU - Lao, Yanbin
AU - Steele, Terry W.J.
AU - Abbas, Hamed K.
N1 - Funding Information:
This work was supported in part by United States Department of Agriculture Cooperative Agreement 58-6402-0-035 Amendment #2.
PY - 2005/12
Y1 - 2005/12
N2 - Studies on biological control of aflatoxin production in crops by pre-infection with non-toxigenic Aspergillus flavus strains have created a need for improved methods to screen isolates for aflatoxigenicity. We have evaluated two empirical aflatoxigenicity tests: (i) yellow pigment production, and (ii) the appearance of a plum-red color in colonies exposed to ammonium hydroxide vapor. Yellow pigments from aflatoxigenic A. flavus were shown to function as pH indicator dyes. Seven pigments representing most of the pigmentation in extracts have been isolated using color changes when chromatography spots were exposed to ammonium hydroxide vapor to guide fractionation. Their structures have been shown to be norsolorinic acid, averantin, averufin, versicolorin C, versicolorin A, versicolorin A hemiacetal and nidurufin, all of which are known anthraquinone pigments on, or associated with, the aflatoxin biosynthetic pathway in Aspergillus spp. Thus, the basis of both empirical tests for aflatoxigenicity is detecting production of excess aflatoxin biosynthetic intermediates.
AB - Studies on biological control of aflatoxin production in crops by pre-infection with non-toxigenic Aspergillus flavus strains have created a need for improved methods to screen isolates for aflatoxigenicity. We have evaluated two empirical aflatoxigenicity tests: (i) yellow pigment production, and (ii) the appearance of a plum-red color in colonies exposed to ammonium hydroxide vapor. Yellow pigments from aflatoxigenic A. flavus were shown to function as pH indicator dyes. Seven pigments representing most of the pigmentation in extracts have been isolated using color changes when chromatography spots were exposed to ammonium hydroxide vapor to guide fractionation. Their structures have been shown to be norsolorinic acid, averantin, averufin, versicolorin C, versicolorin A, versicolorin A hemiacetal and nidurufin, all of which are known anthraquinone pigments on, or associated with, the aflatoxin biosynthetic pathway in Aspergillus spp. Thus, the basis of both empirical tests for aflatoxigenicity is detecting production of excess aflatoxin biosynthetic intermediates.
KW - Aflatoxigenicity test
KW - Aflatoxin
KW - Anthraquinone Pigment
KW - Aspergillus flavus
KW - Biosynthetic intermediates
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U2 - 10.1016/j.bioorg.2005.09.002
DO - 10.1016/j.bioorg.2005.09.002
M3 - Article
C2 - 16260026
AN - SCOPUS:27944438891
SN - 0045-2068
VL - 33
SP - 426
EP - 438
JO - Bioorganic Chemistry
JF - Bioorganic Chemistry
IS - 6
ER -