DLlactic

DL-lactic acid, or racemic lactic acid, is the racemate that consists of equal amounts of the D- and L-enantiomers of lactic acid (2-hydroxypropanoic acid). Its chemical formula is C3H6O3 and its molecular weight is about 90.08 g/mol. At room temperature it is typically a colorless, hygroscopic liquid or syrup and is miscible with water. The molecule contains a carboxyl group that gives lactic acid acidic properties, with a pKa around 3.86.

Biologically, lactic acid arises in two common contexts. In humans and many animals, L-lactic acid is produced during anaerobic glycolysis in muscles and red blood cells when oxygen is limited. D-lactic acid is typically produced by certain bacteria in the gut or during fermentation. In most healthy adults, D-lactic acid is present only in small amounts, but excessive D-lactic acid can contribute to D-lactic acidosis in people with specific intestinal conditions.

Industrial relevance, production, and uses: DL-lactic acid can be produced by fermentation of carbohydrates and is sometimes used as a chemical feedstock or acidity regulator in various applications. It is also a precursor to polymeric materials: lactide, obtained from lactic acid, can be polymerized to produce poly(lactic acid) (PLA). The racemic DL form yields a amorphous or less crystalline polymer (PDLLA) with different material properties compared with polymers derived from the pure D- or L-enantiomers.

Safety and regulatory notes: Lactic acid and its salts and esters are widely used in food, cosmetics, and pharmaceuticals and are generally regarded as safe when used appropriately. Concentrated DL-lactic acid can be an irritant to skin and eyes and should be handled with standard safety precautions. In clinical contexts, elevated D-lactic acid levels may be of concern for susceptible individuals.