Abstract: Artificial modulation of ascorbate level was investigated in mice capable of de novo synthesis of ascorbate. When mice were given exogenous ascorbate or its physiological precursor, L-gulono-?-lactone, the plasma level of ascorbate was elevated substantially but immediately returned to the basal levels. Comparably, the administration of ascorbate oxidase caused a rapid disappearance of plasma ascorbate but followed by an immediate restoration of ascorbate. These results indicate the difficulties encountered in the modulation of ascorbate level in the animal. However, the circulation life of the exogenous ascorbate oxidase in the animal was successfully extended by chemical modification with methoxypolyethylene glycol. The modified enzyme retained a full activity and exerted a remarkably prolonged depletion of plasma ascorbate compared with the native enzyme.

Abstract: Disclosed herein is a method for producing 4-hydroxy-5-methyl-3[2H]-furanone and new uses thereof.4-hydroxy-5-methyl-3[2H]-furanone may be extracted from the plants of Pinaceae species and may advantageously be used as an anti-oxidant or for whitening the skin. The compound or extracts containing same is not irritative to the skin and can safely be applied to the skin.