Птеролактам

Description

Pterolactam is a natural alkaloid with a simple structure: (+)-5-methoxy-2-pyrrolidinone, that is, a γ-lactam with a methoxyl group in position 5. It is isolated from the rhizomes of Cibotium barometz, a fern used in traditional Chinese medicine. The molecule is an N,O-acetal of the lactam type: the C-5 atom carries both a ring nitrogen and a methoxy group.

Basic Attributes

• CAS No.: 38072-88-7
• Chemical formula: C5H9NO2
• Molecular weight: 115.132
• Exact weight: 115.13
• EU number: 613-389-2
• PSA specifications: 38.3
• XLogP3: −2.18

Physico-chemical indicators

• Density: 1.1 ± 0.1 g/cm³
• Melting point: 56–67 °C
• Boiling point: 268.5 ± 33.0 °C at 760 mm Hg. Art.
• Flash point: 116.2 ± 25.4 °C
• Refractive index: 1.461
• Solubility in water: 3.447 × 10⁵ mg/l at 25 °C (calculated value)

The calculated solubility of 3.447 × 10⁵ mg/l is about 345 g per liter, that is, the substance mixes with water almost unlimitedly. It is consistent with the XLogP3 index of −2.18: the compound is strongly hydrophilic, extraction with organic solvents from the aqueous phase is difficult, evaporation and reverse phase chromatography with a small proportion of organics are used for isolation. A wide melting range of 56–67 °C is typical for samples that have not undergone deep purification.

Structure and stability

A five-membered ring of 2-pyrrolidinone with an amide bond and a methoxy group at the carbon atom adjacent to the nitrogen. This N,O-acetal unit is hydrolyzed in an acidic environment: methanol is eliminated, forming 5-hydroxy-2-pyrrolidinone, which is in equilibrium with the open aldehyde amide form. The practical conclusion is that acidic conditions are not used during sample preparation and storage. The (+) sign in the name indicates optical activity: the C-5 atom is a stereocenter.

Purpose

• analytical standard for studying the composition of Cibotium barometz and other ferns
• reference compound in works on alkaloids of the pyrrolidinone series
• substance for biological screening
• initial synthon in organic synthesis: the N,O-acetal center serves as a convenient electrophilic site for the introduction of nucleophiles into position 5 of the lactam ring

Storage

Tightly closed container, negative temperature, lack of light and moisture. Hydrophilicity and tendency to hydrolysis require protection from atmospheric moisture. The product card does not contain a separate set of hazard phrases; they work in gloves and glasses, the powder is poured in a fume hood. The product is intended for research purposes.