Biosynthesis of citrinin in Aspergillus terreus.
Biosynthetic Pathway of Citrinin in the Filamentous …
The selective effect of various levels of phosphate and nitrate (as fertilizers) on biosynthesis of aflatoxin byAspergillus parasiticus var.globosus, and citrinin byA. terreus var.aureus was studied in defined culture medium. Phosphate at 35–175 mmol per 50 mL decreased aflatoxin production, but increased citrinin synthesis. Nitrate at 73–365 mmol per 50 mL stimulated the synthesis of aflatoxin but depressed that of citrinin. A rise in the levels of nitrate and phosphate led to a decrease in aflatoxin production, an increase in citrinin production and an accumulation of mycelial phosphate and nitrate contents.
The Biosynthesis of Citrinin in Penicillium citrinum
A. terreus is an especially prolific producer of secondary metabolites. A few of the compounds that are produced by A. terreus are aspulvinone (), asterric acid (), asterriquinone (), butyrolactone I (), citrinin (), emodin (), geodin (), itaconate (), lovastatin (, ), questrin (), sulochrin (), and terrecyclic acid (). Lovastatin, also known as mevinolin or monacolin K, is clinically useful for reducing serum cholesterol () and slowing the progression of atherosclerosis (). Lovastatin and related compounds inhibit cholesterol synthesis by inhibiting the rate-limiting step in cellular cholesterol biosynthesis, namely, the conversion of hydroxymethylglutaryl coenzyme A to mevalonic acid by 3-hydroxy-3-methylglutaryl-coenzyme A reductase. 3-Hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors, such as lovastatin, reversibly inhibit cell proliferation by inducing a block in the G1 phase of the cell cycle in a wide variety of normal and tumorigenic mammalian cell lines (, ).