Levorotaattorinen

Levorotaattorinen, often abbreviated as levo- or l-, is a term used in chemistry and biology to describe a substance that rotates the plane of plane-polarized light to the left, or counterclockwise, when viewed from the direction of the light source. This property is known as optical activity or levorotation.

Substances that exhibit levorotation are chiral molecules, meaning they are non-superimposable on their mirror images, much like a left and right hand. The specific direction of rotation is a characteristic property of a chiral molecule, just like its melting point or boiling point. It is important to note that levorotation is not directly related to the molecule's absolute configuration (e.g., R or S designation), although there can be a correlation for certain classes of compounds.

A common example of a levorotatory substance is the sugar fructose. Another example is the amino acid L-cysteine. The degree to which a substance rotates plane-polarized light is measured by its specific rotation, a value that depends on the substance, concentration, solvent, temperature, and the wavelength of light used. Levorotatory substances will have a negative specific rotation value. The opposite of levorotatory is dextrorotatory, which indicates rotation of plane-polarized light to the right, or clockwise.