Margaret Moreland

Synthesis of the antibiotic cortalcerone from D-glucose using pyranose 2-oxidase and a novel fungal enzyme, aldos-2-ulose dehydratase

Using two enzymes purified from the white-rot fungus, Polyporus obtusus, 5% solutions of D-glucose have been quantitatively converted in vitro into D-arabino-hexos-2-ulose (D-glucosone) and subsequently into a compound having antimicrobial activity. The antibiotic has been shown by nuclear magnetic resonance and mass spectroscopy to be chemically identical to a previously described fungal metabolite known as cortalcerone. Based on kinetic analysis of the synthetic process, a pathway for the biosynthesis of cortalcerone is proposed, involving both chemical rearrangement and enzymically catalyzed steps. Two enzymes, pyranose 2-oxidase and a previously uncharacterized D-arabino-hexos-2-ulose-utilizing enzyme, may be sufficient for the biosynthesis of cortalcerone from glucose in vivo. The D-arabino-hexos-2-ulose-utilizing enzyme dehydrates certain aldosuloses and has been named aldos-2-ulose dehydratase. The enzyme, which appears to be a dimer of 95-kDa subunits, has been purified 450-fold. Additional properties of aldos-2-ulose dehydratase are described, including its apparent ability to catalyze two different steps in the proposed biosynthetic pathway for cortalcerone.

DMSO is a substrate for chloroperoxidase

Dimethyl sulfoxide has been used as a nonaqueous organic solvent in haloperoxidase reactions. However, it has been found that this solvent is not inert under chloroperoxidase reaction conditions, forming the halosulfoxide, the sulfone, and the halosulfone. The biological significance of this finding is briefly discussed.