Characterization of Aziridine-Forming α-Ketoglutarate-Dependent Oxygenase in l-Isovaline Biosynthesis.

l-Isovaline biosynthesis by TqaLFM- from was demonstrated . The biochemical analysis of the α-ketoglutarate-dependent oxygenase TqaL- revealed that it produces (2,3)-3-ethyl-3-methylaziridine-2-carboxylic acid from l-isoleucine, thus exhibiting a stereoselectivity different from those of the reported homologues. Remarkably, a single mutation on I295 in TqaL- completely exchanged its stereoselectivity to produce the C-3 stereoisomer.

Total Syntheses and Chemical Biology Studies of Hymeglusin and Fusarilactone A, Novel Circumventors of β-Lactam Drug Resistance in Methicillin-Resistant Staphylococcus aureus.

Hymeglusin, a previously known eukaryotic hydroxymethylglutaryl-CoA (HMG-CoA) synthase inhibitor, was identified as circumventing the β-lactam drug resistance in methicillin-resistant Staphylococcus aureus (MRSA). We describe the concise total syntheses of a series of natural products, which enabled determination of the absolute configuration of fusarilactone A and provided structure-activity relationship information. Based on previous reports, we speculated that the target protein of this circumventing effect may be MRSA bacterial HMG-CoA synthase (mvaS).

Kozupeptins, Antimalarial Agents Produced by Paracamarosporium Species: Isolation, Structural Elucidation, Total Synthesis, and Bioactivity.

Kozupeptins A and B, novel antimalarial lipopeptides, were isolated from the culture broths of Paracamarosporium sp. FKI-7019. They exhibited potent antimalarial activity against chloroquine-sensitive and -resistant Plasmodium falciparum strains in vitro.