IDENTIFICATION OF O-METHYLSTERIGMATOCYSTIN AS AN AFLATOXIN-B1 AND AFLATOXIN-G1 PRECURSOR IN ASPERGILLUS-PARASITICUS
IDENTIFICATION OF O-METHYLSTERIGMATOCYSTIN AS AN AFLATOXIN-B1 AND AFLATOXIN-G1 PRECURSOR IN ASPERGILLUS-PARASITICUS
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DOI：
10.1128/aem.53.5.1028-1033.1987
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发表时间：
1987-05-01
影响因子：
4.4
通讯作者：
HILL, RA
中科院分区：
文献类型：
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作者：
BHATNAGAR, D;MCCORMICK, SP;HILL, RA
寄生曲霉CP461 （SRRC 2043）分离株没有检测到黄曲霉毒素，但积累了o -甲基sterigmatocystin （OMST）。当在低糖培养基中饲喂streigmatocystin （ST）时，该分离物的OMST积累增加，而黄曲霉毒素没有合成。将放射性标记的[14C]OMST喂给不产生黄曲霉毒素、不产生st和不产生OMST的寄生蜂AVN-1突变体（SRRC 163）的静息菌丝，产生14C标记的黄曲霉毒素B1和G1；10 nmol的OMST产生7.8 nmol的B1和1.0 nmol的GH， 10 nmol的ST产生6.4 nmol的B1和0.6 nmol的G1。AVN-1在ST饲养实验中对黄曲霉毒素合成的时间过程研究表明，OMST是在黄曲霉毒素合成开始时由霉菌合成的。食用菌饲喂试验回收的黄曲霉毒素总量高于饲喂食用菌的试验。这些结果表明，OMST是sterigmatocystin与黄曲霉毒素B1和G1之间的黄曲霉毒素生物合成途径中的真正代谢物，而不是之前认为的分流代谢物。
An isolate of Aspergillus parasiticus CP461 (SRRC 2043) produced no detectable aflatoxins, but accumulated O-methylsterigmatocystin (OMST). When streigmatocystin (ST) was fed to this isolate in a low-sugar medium, there was an increase in the accumulation of OMST, without aflatoxin synthesis. When radiolabeled [14C]OMST was fed to resting mycelia of a non-aflatoxin-, non-ST-, and non-OMST-producing mutant of A. parasiticus AVN-1 (SRRC 163), 14C-labeled aflatoxins B1 and G1 were produced; 10 nmol of OMST produced 7.8 nmol of B1 and 1.0 nmol of GH, while 10 nmol of ST produced 6.4 nmol of B1 and 0.6 nmol of G1. A time course study of aflatoxin synthesis in ST feeding experiments with AVN-1 revealed that OMST is synthesized by the mold during the onset of alflatoxin synthesis. The total amount of aflatoxins recovered from OMST feeding experiments was higher than from experiments in which ST was fed to the resting myeclia. These results suggest that OMST is a true metabolite in the aflatoxin biosynthetic pathway between sterigmatocystin and aflatoxins B1 and G1 and is not a shunt metabolite, as thought previously.