Planned modification and newly designed MAO inhibitors. I = (4,6-dimethoxy-1,3,5-triazin-2-yl) amino acid derivatives; X = O; II is (4,6-dimorpholino-1,3,5-triazin-2-yl) amino acid derivatives or X = CH2; II is (4,6-dipiperidino-1,3,5-triazin-2-yl) amino acid derivatives.