Searching for a UV-filter in the eyes of high-flying birds

The eye lens is a unique organ as no cells can be replaced throughout life. This makes it decisive that the lens is protected against damaging UV-radiation. An ultraviolet (UV)-absorbing compound of unknown identity is present in the aqueous humor of geese (wild and domestic) and other birds flying at high altitudes. A goose aqueous humor extract, that was believed to contain the UV protective compound which was designated as compound X, was fractionated and examined using a variety of spectroscopic techniques including LC-MS and high field one- and two dimensional-NMR methods. A series of compounds were identified but none of them appeared to be the UV protective compound X. It may be that the level of the UV protective compound in goose aqueous humor is much less than the compounds identified in our investigation, or it may have been degraded by the isolation and chromatographic purification protocols used in our investigations.

Automated summary

Research discovered an unknown UV-absorbing compound in the aqueous humor of geese, yet the protective compound X was not found. It is possible that the level of UV protective compound in goose aqueous humor is lower than previously identified compounds, or that it may have degraded during the isolation and chromatographic purification processes used.