PHOTOSENSITIZED OXIDATIVE REACTION OF 2,5-DIMETHYL-4-HYDROXY-3(2H)-FURANONE

2,5-Dimethyl-4-hydroxy-3(2H)-furanone (DMHF) in absolute alcohol conta ining chlorophyll was exposed to light while being bubbled with oxygen . The photooxidation products, including ethyl pyruvate, ethyl lactate , acetic acid, ethyl 2-acetoxypropionate, acetoxyacetone, 1,2-ethanedi ol, acetoxy-2,3-butanedione, 2-oxopropyl 2-acetoxypropionate, lactic a cid, and 2-acetoxypropionic acid were identified using gas chromatogra phy (GC) and gas chromatography-mass spectrometry (GCMS). Possible for mation mechanisms for these products are postulated. The antiphotooxid ative effect of capsanthin and lutein on DMHF in absolute alcohol cont aining chlorophyll was studied under light exposure while bubbling wit h oxygen. Both capsanthin and lutein showed the antiphotooxidative eff ect on DMHF, and their antiphotooxidative activity increased with incr easing concentration. The activity of capsanthin, which contains 11 co njugated double bonds, a conjugated keto group, and one cyclopentane r ing, was higher than that of lutein, which contains 10 conjugated doub le bonds but neither a conjugated keto group nor a cyclopentane ring.