High impact information on NSC 138557

• In contrast, the mutants Dis-1 and Dis-2, which are derived from NOR-1 by insertional inactivation of fas-1, produced unexpectedly low amounts of norsolorinic acid in the presence of hexanoylNAC [1].
• CONCLUSIONS: The impaired ability of Dis-1 and Dis-2, harboring modified FAS-1 enzymes, to carry out norsolorinic acid synthesis implies the need for FAS-1 (and possibly also FAS-2) to physically associate with the PKS before biosynthesis can begin [1].
• We describe a novel screen for detecting mutants defective in stc gene cluster activity by use of a genetic block early in the ST biosynthetic pathway that results in the accumulation of the first stable intermediate, norsolorinic acid (NOR), an orange-colored compound visible with the unaided eye [2].
• Furthermore, microscopic observations showed that the ST and AF precursor norsolorinic acid accumulated in peroxisomes of all three Aspergilli [3].
• An 8-kb SacI subclone of cosmid NorA complemented fas-1A only, resulting in accumulation of norsolorinic acid [4].

Biological context of NSC 138557

• Southern analysis of genomic DNA isolated from the NA-accumulating transformants indicated that the wild-type nor-1 gene in the chromosome had been replaced by the nonfunctional allele carried on pNA51-82 [5].
• An Aspergillus parasiticus cDNA library was screened with monoclonal antibody raised against a purified A. parasiticus 43-kDa protein demonstrating norsolorinic acid reductase (NOR) activity [6].
• The green-spored, prototrophic diploids resembled haploid wild-type strains in that they produced high levels of aflatoxin, low levels of versicolorin A, and no detectable norsolorinic acid [7].

Anatomical context of NSC 138557

• When the postmicrosome (cytosol) fraction of NIAH-26, which had been prepared from the culture in YES medium, was incubated with norsolorinic acid (NA) in the presence of NADH or NADPH, averantin (AVN) was produced [8].

Associations of NSC 138557 with other chemical compounds

• Conventional quantitative chromatographic analyses of separated materials indicated that aflatoxin from Aspergillus parasiticus, norsolorinic acid from a mutant of A. parasiticus, and secalonic acid D from Penicillium oxalicum were concentrated in the mycelium-substrate matrices and not in the spores [9].
• Isolation of the Anthraquinone Norsolorinic acid from Cinchona ledgeriana1 [10].
• The reaction catalyzed by the dehydrogenase was optimum at pH 8.5 and between 25 degrees to 35 degrees C. The Km of the enzyme for NA and NADPH was determined to be 3.45 microM and 103 microM respectively [11].

Analytical, diagnostic and therapeutic context of NSC 138557

• Transformation of A. parasiticus NR-3 (niaD Afl+) with pNA51-82 resulted in niaD+ transformants that accumulated NA and produced reduced levels of aflatoxin as determined by thin-layer chromatography and enzyme-linked immunosorbent assay analyses of extracts from mycelia and the growth medium [5].

References