Tag: Stereochemistry

According to research published by the National Institutes of Health, N-acetylcysteine (NAC), N-acetyl-L-cysteine, and several other names are all designations for the same compound. For consumers, this means that these names are used interchangeably to describe the same active ingredient found in supplements and medications. The seemingly confusing 'L-' simply specifies the biologically active form of the amino acid from which the compound is derived.

The human body is primarily fueled by D-sugars, which are absorbed and metabolized differently than their L-isomers. While galactose is a simple sugar, the prefix 'D-' in D-galactose specifies its exact stereochemical configuration, a crucial detail that determines its biological role and distinguishes it from its less common mirror image, L-galactose.

Despite having the same chemical formula ($C_6H_{12}O_6$), the monosaccharide glucose is significantly more stable than its epimer, galactose. This difference in stability is a direct result of their stereochemical arrangement and the resulting energetic strain in their cyclic chair conformations.