It featured extensive libraries for functional groups, rings, and amino acids, significantly speeding up the drawing process.
Given that ISIS Draw 2.5 is an older version, you might also consider looking into more current alternatives for drawing chemical structures, such as: isis draw 2.5 free download
It was built for older versions of Windows (98/XP/7). You may need to run it in Compatibility Mode on Windows 10 or 11. and amino acids
: Warns about incorrect valences, overlapping atoms, or bonds that are too short. or bonds that are too short.