Hexacosanoic acid-d4 is the deuterium labeled Hexacosanoic acid[1]. Hexacosanoic acid is a long-chain fatty acid related to various diseases such as adrenoleukodystrophy (ALD), adrenomyeloneuropathy (AMN) and atherosclerosis[2].
Nicotinuric acid-d4 is the deuterium labeled Nicotinuric acid. Nicotinuric acid is an acyl glycine. Nicotinuric acid is a metabolite of nicotinic acid[1][2].