4β-Hydroxycholesterol-[d5]

4β-Hydroxycholesterol-[d5] is a sterol that is widely used in research laboratories as a stable isotope-labeled internal standard. The compound is labeled with deuterium at the C-5 position of the sterol ring, which makes it useful for quantification studies. This is because, unlike other forms of cholesterol, 4β-Hydroxycholesterol-[d5] can be reliably distinguished from endogenous cholesterol in biological samples using mass spectrometry. 4β-Hydroxycholesterol-[d5] is a product of cholesterol metabolism and is formed in the liver through the action of the enzyme CYP3A4. The compound plays a pivotal role in the regulation of cholesterol metabolism and is also a precursor for the synthesis of many important steroid hormones. In research, 4β-Hydroxycholesterol-[d5] is used to study the regulation of cholesterol metabolism and the role of CYP3A4 in this process. It is also used as an internal standard for the quantification of other sterols, including 4β-hydroxycholesterol, in biological samples. Overall, 4β-Hydroxycholesterol-[d5] is an important tool for researchers studying cholesterol metabolism, as it allows for accurate quantification of key sterols in biological samples. Its stable isotope labeling makes it a reliable internal standard, and its chemical properties make it an ideal candidate for use in mass spectrometry-based quantification studies.