5-Hydroxyindole-3-acetic acid-D5是一种氘代标记的5-Hydroxyindole-3-acetic acid。5-Hydroxyindole-3-acetic acid是血清素或变肾上腺素的主要代谢产物，常用于作为神经内分泌肿瘤的生物标志物。

Thiamine-13C4 hydrochloride是Thiamine Hydrochloride (T0894)的 13C 的标记化合物。Thiamine Hydrochloride的CAS号为67-03-8。Thiamine hydrochloride是一种必需的微量营养素，是许多中枢代谢酶的辅因子。

L-Methionine-D8是L-Methionine (T4844)的氘代物。L-Methionine是必需氨基酸 Methionine 的 L-异构体，具有强肝解毒作用，并作为肝脏保护剂。

Urea-D4是Urea (T0738)的氘代物。Urea为强效蛋白质变性剂，通过直接和间接机制发挥作用。除此之外，它是有效的润肤剂和角质层分离剂，也被用作利尿剂。血尿素氮 (BUN)常用于评估肾功能。作为肥料中的氮源，Urea在化学工业中是重要的原料。

ATP dipotassium (Adenosine 5'-triphosphate dipotassium) is a vital compound involved in energy storage and metabolism within living organisms. It plays a crucial role in supplying metabolic energy for driving pumps and acts as a coenzyme in cellular processes. Additionally, ATP dipotassium functions as a significant endogenous signaling molecule contributing to immunity and inflammation.

NADP+ is the oxidized form of the electron donor nicotinamide adenine dinucleotide phosphate . It serves as a cofactor in various biological reactions. In addition, the balance between these reduced and oxidized forms plays key roles in diverse cellular functions, including cell survival, the maintenance of redox status, and intracellular signaling. For example, binding of NADP+ to β-subunits of Kv channels activates ion transport, whereas NADPH stabilizes channel inactivation. NADP+ is biosynthesized from NAD+ by NAD kinase, with ATP as the phosphoryl donor.

Cyclohexanoyl coenzyme A (CHCoA) is an acyl CoA that contains a cyclohexane group. It is the activated form of cyclohexane carboxylic acid (CHC) in R. palustris. CHC is converted to CHCoA by a succinyl-CoA CHC CoA transferase, and CHCoA is then degraded by a dehydrogenase. CHCoA is converted to hippuric acid in submitochondrial fractions isolated from guinea pig liver.

Methylmalonyl coenzyme A (Methylmalonyl-CoA) 是单链脂肪酸、胆固醇以及某些氨基酸（例如缬氨酸、异亮氨酸、蛋氨酸、苏氨酸）分解后的产物。通过甲基丙二酸单酰辅酶 A 变位酶 (MCM) 和其辅酶维生素 B12，Methylmalonyl coenzyme A 可以被催化转化为琥珀酰辅酶 A。

Palmitoyl L-Carnitine-d3 Hydrochloride是棕榈酰 L-肉碱的氘代衍生物。棕榈酰 L-肉碱是一种长链酰基肉碱，由棕榈酸和肉碱缩合而成，在线粒体脂肪酸 β-氧化和能量代谢中起关键作用。在病理状态下（如心肌缺血），棕榈酰 L-肉碱会在细胞膜内积聚。研究表明，它能改变膜脂环境并调节 KATP 通路，从而影响心肌细胞的电生理特性。作为氘代标记物，该化合物主要在基于质谱（LC-MS/MS）的定量分析中用作内标，利用氘代诱导的药代动力学动力学同位素效应（KIE）来提高检测的精确度。