PROTEIN GLYCATION INHIBITORS FROM THYME (THYMUS-VULGARIS)

Nonenzymatic glycation of bovine serum albumin (BSA) was inhibited in vitro by some extracts of 34 kinds of spices, The methanol extract of thyme (Thymus vulgaris) had the most potent inhibitory activity among them. Chromatographic purification yielded four flavonoids, quercetin (1), eriodictyol (2), 5,6,4'-trihydroxy-7,8,3'-trimethoxyflavone (3), and cirsilineol (4). These known flavonoids suppressed the levels of a dvanced glycation end products (AGEs) and fructosamines, shown by the measurement of specific fluorescent groups and the reduction of nitrob lue tetrazolium (NET), respectively, The inhibitory activities were co mpared with those of other structure-related flavonoids and aminoguani dine.