HA6977 DL-Synephrine Powder (CAS No. 94-07-5)

DL-Synephrine Powder Description

DL-Synephrine Powder is a white to off‐white crystalline powder that exhibits dual stereoisomerism as a racemic mixture of D‐ and L‐enantiomers. It is chemically designated as 4-[1-hydroxy-2-(methylamino)ethyl]phenol and has a molecular weight of 167.20 g/mol. The powder has a melting point range of 184°C to 187°C. This biogenic amine is moderately soluble in water (approximately 25 mg/mL at 20°C) and shows higher solubility in methanol, ethanol, and dimethyl sulfoxide. Its crystalline structure is of the orthorhombic type, and infrared spectroscopy identifies absorption bands at 3350 cm⁻¹ (O-H stretch), 1605 cm⁻¹ (aromatic C=C), and 1240 cm⁻¹ (C-O phenolic).

The compound functions as a selective α₁-adrenergic receptor agonist. It binds with a half-maximal effective concentration of 8.2 micromolar. Its molecular configuration comprises a para-hydroxylated phenyl ring linked to an ethanolamine side chain with an N-methyl substitution, thereby mimicking endogenous catecholamines in structure. UV-Vis spectroscopy reveals a maximum absorbance at 274 nm in aqueous solutions, while nuclear magnetic resonance spectroscopy displays distinct aromatic proton signals between 6.7 and 7.2 ppm. Thermal gravimetric analysis confirms stability up to 85°C; decomposition commences through oxidative pathways. The crystalline form exhibits hygroscopicity, with moisture uptake below 3% at 60% relative humidity, and shows birefringence under polarised light microscopy. Chromatographic purity standards require a primary peak area of ≥98% as determined by reverse-phase HPLC using methanol-water mobile phases.

DL-Synephrine Powder Applications

• Nutraceuticals: Incorporated in thermogenic weight management formulations at a concentration of 5–20%, utilising measured lipolytic α1-adrenergic receptor activation. The dosage does not exceed 100 mg per day.
• Pharmaceuticals: Employed as an α1-selective agonist prototype for cardiovascular research and the development of decongestants; requirements include a purity of ≥98% and receptor specificity (EC50 = 8.2μM).
• Cosmetics: Formulated in topical fat‐reduction serums at concentrations between 0.5–2% w/w, thereby inducing local adipocyte-specific adrenergic stimulation without systemic absorption.
• Clinical Diagnostics: Used as a reference standard in HPLC/GC-MS assays for the screening of sympathomimetic drugs, with a retention time of 6.3±0.2 minutes on a C18 column.
• Sports Science: Integrated in ergogenic aids designed for anaerobic performance enhancement via quantitative catecholamine receptor modulation.

DL-Synephrine Powder Packaging

The products are packaged in customised cartons of various sizes, determined by the material dimensions. Small items are securely packed in PP boxes, while larger items are placed in custom wooden crates. Packaging is tailored with appropriate cushioning materials to provide optimal protection during transportation.

Packaging: Carton, Wooden Box, or Customized.

Kindly review the packaging details provided for your reference.

Manufacturing Process

1.       Testing Method

(1)    Chemical Composition Analysis – Verified using techniques such as GDMS or XRF to ensure compliance with the purity requirements.

(2)    Mechanical Properties Testing – Includes tensile strength, yield strength, and elongation tests to assess material performance.

(3)    Dimensional Inspection – Measures thickness, width, and length to confirm adherence to specified tolerances.

(4)    Surface Quality Inspection – Checks for defects such as scratches, cracks, or inclusions using visual and ultrasonic examination.

(5)    Hardness Testing – Determines material hardness to confirm uniformity and mechanical reliability.

Please refer to the SAM testing procedures for detailed information.

DL-Synephrine Powder FAQs

Q1. How does DL-Synephrine differ from natural synephrine in weight management products?

DL-Synephrine is a synthetic racemic mixture that provides consistent α1-adrenergic receptor activation (EC50 = 8.2μM), whereas natural citrus extracts display variable D/L isomer ratios. Its standardised melting point (184–187°C) and ≥98% HPLC purity ensure reproducibility across batches in thermogenic formulations.

Q2. What analytical methods confirm DL-Synephrine purity in bulk supplements?

Reverse-phase HPLC with methanol-water gradients (65:35 v/v) is mandated, detecting the primary peak at 6.3±0.2 minutes retention time. Complementary FTIR analysis should register a characteristic phenolic C-O stretch at 1240 cm⁻¹ and demonstrate the absence of solvent residues below 500 ppm.

Q3. Why is DL-Synephrine preferred over ephedrine in pharmaceutical research?

DL-Synephrine exhibits selective α1-agonism without significant β-adrenergic activity, thereby reducing cardiovascular side effects. Its orthorhombic crystalline structure enhances stability during in vitro assays, and thermal decomposition commences only above 85°C.

Related Information

Common Preparation Methods

Commercial production involves the reductive amination of m-hydroxyphenylacetone with methylamine under a hydrogen atmosphere (3 atm, Pd/C catalyst) in anhydrous ethanol at 65°C for 12 hours. The crude product is subjected to vacuum distillation to remove solvents, followed by recrystallisation from a methanol-water (7:3 v/v) mixture to yield orthorhombic crystals. Critical purification is achieved via reverse-phase HPLC using a methanol-water (65:35 v/v) mobile phase to isolate the racemate, targeting a purity of ≥98.5% as confirmed by a retention time of 6.3±0.2 minutes and a characteristic FTIR phenolic peak at 1240 cm⁻¹. The final product consistently exhibits a melting point range of 184–187°C and a decomposition onset above 85°C, thereby ensuring batch conformity for pharmaceutical applications.