Mycosporine-like amino acids (MAAs) were extracted from a unicellular cyanobacterium (Euhalothece sp.) isolated from a gypsum crust on the bottom of a hypersaline saltern pond in Eilat, Israel. When grown at high light intensities, this isolate contained high concentrations of two MAAs, one showing maximum optical density at 331 nm and one at 362 nm. The compound absorbing at 331 nm was purified by preparative high performance liquid chromatography, and its structure was elucidated by one-dimensional ((1)H and (13)C) and two-dimensional nuclear magnetic resonance, mass spectrometry and amino acid analysis, and identified as mycosporine-2-glycine. This is the first report of mycosporine-2-glycine in cyanobacteria.