Biochemical Background and Biosynthetic Pathway

17α-Hydroxy Progesterone (17α-OHP) is a C21 steroid formed when progesterone is hydroxylated at the 17α position by the enzyme CYP17A1 (17α-hydroxylase), a cytochrome P450 enzyme expressed in the adrenal cortex and gonads. This reaction constitutes a pivotal branch point in steroidogenesis: 17α-OHP can be further converted to 11-deoxycortisol (and ultimately cortisol) via the action of CYP21A2 (21-hydroxylase), or alternatively undergo C17–20 lyase cleavage by CYP17A1 to yield androstenedione, the precursor to testosterone and estrogens.

Circulating 17α-OHP levels therefore reflect the activity of multiple steroidogenic enzymes, making it a sensitive marker for disorders of adrenal steroidogenesis. In classical congenital adrenal hyperplasia (CAH) caused by 21-hydroxylase deficiency, 17α-OHP accumulates to markedly elevated concentrations, underpinning its clinical utility as a neonatal screening analyte and diagnostic biomarker.

Physicochemical Properties and Formulation

17α-OHP is a white to off-white crystalline powder with a molecular weight of 330.46 g/mol (CAS 68-96-2) and the molecular formula C₂₁H₃₀O₃. The compound is sparingly soluble in water but dissolves readily in organic solvents such as ethanol, methanol, dimethyl sulfoxide (DMSO), and chloroform. When preparing stock solutions for cell-based or biochemical assays, dissolution in ethanol or DMSO is recommended, followed by dilution into aqueous buffer or culture medium to a final organic-solvent concentration ≤0.1% (v/v) to minimise cytotoxic effects.

Stability studies on structurally analogous steroids indicate susceptibility to oxidation and photodegradation. Accordingly, stock solutions should be prepared fresh, aliquoted to avoid repeated freeze-thaw cycles, stored at −20 °C in amber vials, and used within recommended shelf-life periods. Verify concentration by UV absorbance (λmax ~240 nm characteristic of the Δ4-3-keto chromophore) or by validated LC-MS/MS prior to critical experiments.

Research and Analytical Applications

Immunoassay calibration and validation: Research-grade 17α-OHP is routinely employed as a calibrator or quality-control material in radioimmunoassay (RIA), enzyme-linked immunosorbent assay (ELISA), and chemiluminescent immunoassay (CLIA) platforms used to quantify endogenous steroid concentrations in serum, plasma, saliva, and dried blood spots.

LC-MS/MS reference standard: Mass spectrometry-based steroid profiling has become the gold standard for clinical and research steroid quantification. Isotopically labelled or unlabelled 17α-OHP is used to construct calibration curves and assess method accuracy and precision in multi-analyte steroid panels.

In vitro steroidogenesis studies: 17α-OHP is used as a substrate or product marker in adrenocortical cell lines (e.g., H295R), primary adrenal cultures, and reconstituted enzyme systems to characterise CYP17A1, CYP21A2, and related enzyme kinetics, inhibitor screening, or the functional impact of genetic variants associated with CAH and polycystic ovary syndrome (PCOS).

Pharmacological research: As a structural analogue of progesterone, 17α-OHP and its esterified derivatives (notably 17α-hydroxyprogesterone caproate) have been studied for progestogenic activity and uterine effects, making the free compound relevant in receptor-binding and competition assays.

Handling, Storage, and Safety Guidelines

Personal protective equipment (PPE): Handle 17α-OHP in accordance with good laboratory practice for biologically active steroids. Wear nitrile gloves, a laboratory coat, and safety glasses. When weighing powder, use a fume hood or biosafety cabinet to prevent inhalation of fine particulates.

Storage: Store the neat compound and stock solutions at −20 °C in a tightly sealed container, protected from light and moisture. Under these conditions, the material is expected to remain stable for at least 24 months from the date of manufacture; however, always verify product-specific shelf-life data on the Certificate of Analysis (CoA).

Disposal: Dispose of 17α-OHP-containing waste in accordance with institutional guidelines and applicable local regulations for biologically active chemical waste. Do not pour organic solvent solutions directly down the drain.

First aid: In the event of skin or eye contact, flush immediately with copious water for at least 15 minutes and seek medical advice. Refer to the Safety Data Sheet (SDS) provided with each shipment for comprehensive hazard information.

Quality Specifications and Ordering Information

Aladdin Scientific supplies 17α-Hydroxy Progesterone (SKU: H137675) as a research-grade reagent. Each lot is accompanied by a Certificate of Analysis documenting identity confirmation (typically by NMR or IR), purity assessment (HPLC ≥98% unless otherwise stated on the CoA), and appearance. Lot-specific data should always be reviewed before use in quantitative or regulatory-context studies.

For procurement inquiries, volume pricing, or custom packaging requirements, please contact Aladdin Scientific customer service. Bulk quantities may be available subject to lead time; consult the product page or your regional representative for current stock status and pricing.