TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compound: (a) Is 6H-pyran-3-one (di-substituted on 2-position by OR2 and -CH(R4)-OR1).R1 and R2 = H or C(=OR3) (preferably H);R3 = hydrocarbyl (preferably 1-5C alkyl);R4 = H or OH.Preferred Components: (a) Is in a solid phase such as powder, tablet, lozenge or pessary. The solid phase stabilized compound is obtainable by freeze-drying or by spray drying (a) with a carrier (preferably dextrin). The stabilized compound comprises (a) and a stabilizing agent that stabilizes (a) and increases the hydrophobicity of the material. The stabilizing agent is antioxidant, free radical quencher, (metal) chelator, emulsifier, UV protectant or polar solvent. The emulsifier is distilled monoglyceride, acetic acid ester of mono- and di-glyceride, citric acid ester of mono- and di-glyceride, lactic acid ester of mono- and di-glyceride, mono- and di-glyceride, polyglycerol ester of fatty acid, polyglycerol polyricinoleate, propylene glycol ester of fatty acid, sorbitan monostearate, sorbitan tristearate, sodium stearoyl lactylate, calcium stearoyl lactylate, diacetyl tartaric acid ester of mono and diglyceride, Tween 20 (RTM; polysorbate 20), Tween 40 (RTM; polysorbate 40), Tween 60 (RTM; polysorbate 60), Tween 80 (RTM; polysorbate 80), Triton X-100 (RTM), sodium dodecyl sulfate or octy-glucoside. The polar solvent is ethanol, methanol and/or glycerol. (a) Is formulated as a composition having pH of at least 7; or is micro-encapsulated antimicrobial compound.    TECHNOLOGY FOCUS - BIOLOGY - Preferred Components: (b) Is an enzyme (preferably dehydratase enzyme, especially pyranosone dehydratase). (c) Is an enzyme (preferably lyase or oxidase enzyme, especially glucan lyase or pyranose-2-oxidase). The primary precursor is glucosone or 1,5-D-anhydrofructose. The second precursor is starch dextrin or glucose.Preferred Material: (A) Further comprises carrier (preferably edible carrier), excipient or diluent. ACTIVITY - Antimicrobial; Fungicide; Antibacterial; Antiseborrheic; Dermatological; Vulnerary.    MECHANISM OF ACTION - Microbial growth inhibitor; Fungal growth inhibitor. Microthecin (a) was tested for growth inhibitory activity against Rhizoctonia solani. A circular plug of fresh mycelium was placed at the centre of potato dextrose agar. Wells were cut along the periphery of the agar plate. In each well (a) (50 microl) was placed and then incubated at room temperature in daylight but protected from sunlight. The minimum inhibitory concentration (MIC) of (a) was found to be 240 parts per million.    ADMINISTRATION - The material is administered topically by spraying. No dosage given.    SPECIFIC COMPOUNDS - Microthecin and cortalcerone are specifically claimed as (a).    EXAMPLE - A mixture comprising 3% 1,5-anhydrous-D-fructose (5 microl) and pyranosone dehydratase (5 microl), sodium phosphate buffer having pH 6 (65 microl) and water (0.7 ml) was heated to form microthecin.