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Polyketides, the ubiquitous products of secondary metabolism in microorganisms, are made by a process resembling fatty acid biosynthesis that allows the suppression of reduction or dehydration reactions at specific biosynthetic steps, giving rise to a wide range of often medically useful products. The lovastatin biosynthesis cluster contains two type I(More)
Lovastatin biosynthesis in Aspergillus terreus involves two unusual type I multifunctional polyketide syntheses (PKSs). Lovastatin nonaketide synthase (LNKS), the product of the lovB gene, is an iterative PKS that interacts with LovC, a putative enoyl reductase, to catalyze the 35 separate reactions in the biosynthesis of dihydromonacolin L, a lovastatin(More)
For centuries the South Pacific islanders have consumed kava (Piper methysticum) as a ceremonial intoxicating beverage. More recently, caplets of kava extracts have been commercialized for their anxiolytic and antidepressant activities. Several cases of hepatotoxicity have been reported following consumption of the commercial preparation whereas no serious(More)
The cytochrome P450 enzymes (P450s or CYPs) form a large family of heme proteins involved in drug metabolism and in the biosynthesis of steroids, lipids, vitamins and natural products. Their remarkable ability to catalyze the insertion of oxygen into non-activated C-H bonds has attracted the interest of chemists for several decades. Very few chemical(More)
The Ginkgo biloba extract EGb761 was tested for its ability to inhibit the major human cytochrome P450 enzymes (CYPs). The full extract was found to strongly inhibit CYP2C9 (Ki = 14+/- 4 microg/mL), and to a lesser extent, CYP1A2 (Ki = 106 +/- 24 microg/mL), CYP2E1 (Ki = 127 +/- 42 microg/mL), and CYP3A4 (Ki = 155 +/- 43 microg/mL). The terpenoidic and(More)
The fungal metabolite lovastatin and its derivatives are widely prescribed cholesterol-lowering drugs that act as potent inhibitors of (3S)-hydroxy-3-methylglutaryl-Coenzyme A reductase (HMG-CoA reductase). These drugs and a number of analogs that have been approved for use in humans are manufactured by fermentation in combination with subsequent chemical(More)
P450 enzymes have attracted the attention of chemists for decades because of their impressive ability to catalyze the hydroxylation of inactivated C--H bonds. However, their use for synthesis in aqueous systems is limited. We report here a survey of the activity of purified human CYP3A4 in the presence of organic solvents or ionic liquids. We show that(More)
Ulcerative colitis is a dynamic, chronic inflammatory condition of the colon associated with an increased colon cancer risk. Ginkgo biloba is a putative antioxidant and has been used for thousands of years to treat a variety of ailments. The aim of this study was to test whether the standardized G.biloba extract, EGb 761, is an antioxidant that can be used(More)
Two mutants of Aspergillus terreus with either the lovC or lovA genes disrupted were examined for their ability to transform nonaketides into lovastatin 1, a cholesterol-lowering drug. The lovC disruptant was able to efficiently convert dihydromonacolin L 5 or monacolin J 9 into 1, and could also transform desmethylmonacolin J 15 into compactin 3. In(More)
Investigation of the post-PKS biosynthetic steps to the cholesterol-lowering agent lovastatin (1) using an Aspergillus terreus strain with a disrupted lovC gene, which is essential for formation of 4a,5-dihydromonacolin L (3), shows that 7 and 3 are precursors to 1, and demonstrates that lovastatin diketide synthase (lovF protein) does not require lovC.