85213-22-5

Usage

Uses

Used in Flavor and Fragrance Industry:
Ethanone, 1-(3,4-dihydro-2H-pyrrol-5-yl)(9CI) is used as a flavoring agent for its characteristic aroma and taste, enhancing the sensory experience of scented rice and other food products.
Used in Aromatherapy:
Ethanone, 1-(3,4-dihydro-2H-pyrrol-5-yl)(9CI) is used as an aromatic compound in aromatherapy, providing a pleasant scent that can have potential therapeutic effects on mood and well-being.
Used in Perfumery:
Ethanone, 1-(3,4-dihydro-2H-pyrrol-5-yl)(9CI) is used as a fragrance ingredient in the creation of perfumes and other scented products, adding a unique and desirable aroma profile to the final product.

InChI:InChI=1/C6H9NO/c1-5(8)6-3-2-4-7-6/h2-4H2,1H3

Upstream product

• 5724-81-2 1-pyrroline 
• 78-98-8 2-oxopropanal 
• 64199-88-8 Δ¹-pyrroline-5-carboxylic acid 
• 43041-12-9 methyl pyrrolidine-2-carboxylate 
• 74-88-4 methyl iodide 
• 184153-60-4 N-(4,5-Dioxo-hexyl)-2-phenyl-acetamide 
• 147-85-3 L-proline 
• 1260068-97-0 2-(1',1'-diethoxyethyl)pyrrolidine 
• 85858-09-9 5-acetylpyrrolidin-2-one 
• 63848-93-1 1-pyrrolidin-2-yl-ethanol 
• 56-86-0 L-glutamic acid 
• 85881-85-2 N-acetyl-5-acetylpyrrolidin-2-one 
• 609-36-9 rac-Pro-OH 
• 57015-08-4 pyrrolidine-2-carbonitrile 

Relevant academic research and scientific papers

Methylglyoxal binds to amines in honey matrix and 2′-methoxyacetophenone is released in gaseous form into the headspace on the heating of manuka honey

Reports on the thermal stability of manuka honey in terms of food processing have been few. This study investigated changes in nine characteristic chemicals of manuka honey during heating. Among these, methylglyoxal (MGO) and 2′-methoxyacetophenone (MAP) were significantly decreased by heating at 90 °C. To elucidate the mechanism for this decrease, artificial honey was prepared from sugars and water with MAP or MGO and then heated. The decrease of MGO was enhanced with L-proline, lysine, or arginine derivatives, accompanied by formation of 2-acetyl-1-pyrroline, MGO-derived lysine dimer, or argpyrimidine, respectively, suggesting that an amino–carbonyl reaction is one pathway for the loss of MGO. The decrease of MAP in the artificial honey depended on the volume of headspace in a vessel. MAP from heated manuka honey was also detected in the gas phase, indicating that MAP was vaporized. Heating could thus reduce the beneficial and/or signature molecules in honey.

An expeditious, high-yielding construction of the food aroma compounds 6-acetyl-1,2,3,4-tetrahydropyridine and 2-acetyl-1-pyrroline

The key compound responsible for the aroma of bread, 6-acetyl-1,2,3,4- tetrahydropyridine (1), has been constructed in an efficient three-step procedure from 2-piperidone in an overall yield of 56%. Compound 1 was liberated in the final step under basic conditions. A related synthetic route produced 2-acetyl-1-pyrroline (2), the principal component of cooked rice, in 10% overall yield.

Efficient Analysis of 2-Acetyl-1-pyrroline in Foods Using a Novel Derivatization Strategy and LC-MS/MS

2-Acetyl-1-pyrroline (2-AP) is a key odorant in many foods, such as aromatic rice and wheat bread, with a very low odor threshold of 0.05 μg/L in water. The small molecule with a popcornlike, roasty odor is generated biologically or by Strecker degradation within the Maillard-reaction cascades during thermal food processing with methylglyoxal and 1-pyrroline as the main direct precursors. Numerous gas-chromatographic methods for the analysis of 2-AP have been published, but the reactivity of the compound leads to discrimination or degradation during sample workup. We developed a novel derivatization method for 2-AP with o-phenylenediamine followed by HPLC-MS/MS analysis of the resulting stable quinoxaline. The precision (7%), repeatability (14%), recovery (92%), linearity (0.79-500 μg/kg), limit of detection (LOD, 0.26 μg/kg), and limit of quantitation (LOQ, 0.79 μg/kg) were validated for rice matrix and were excellent as compared with those of methods published before. With the novel method, 2-AP levels in typical foods like aromatic rice (131 μg/kg), wheat bread (18 μg/kg), brown bread (18 μg/kg), rye bread (18 μg/kg), and popcorn (38 μg/kg) were determined.

2 - acetyl -1 - pyrroline synthetic method

The invention discloses a synthesis method of 2-acetyl-pyrroline. The synthesis method comprises the following steps of: (1), dissolving pyrrolidine-2-formonitrile hydrochloride in inorganic alkali liquor, carrying out extraction for a plurality of times, combining organic layers, adding a drying agent for drying and dehydrating, filtering, and removing volatile components in filtrate to obtain an intermediate product; (2), dissolving the intermediate product obtained in the last step into an organic solvent, dropwise adding tert-butyl hypochlorite to carry out halogenating reaction, then adding potassium tert-butoxide to carry out elimination reaction, filtering and removing volatile components in filtrate to obtain pyrroline-2-formonitrile; (3), dissolving the pyrroline-2-formonitrile in an organic solvent, adding a Grignard reagent to carry out Grignard reaction, then adding acid liquor to carry out hydrolysis, carrying out extraction for a plurality of times, combining organic layers, adding a drying agent for drying and dehydrating, filtering, and removing volatile components in the filtrate to obtain a product. The synthesis method disclosed by the invention is simple and easy to implement, and high in yield; he obtained product is very high in purity, low in energy consumption and lower in cost.

New short and general synthesis of three key Maillard flavour compounds: 2-Acetyl-1-pyrroline, 6-acetyl-1,2,3,4-tetrahydropyridine and 5-acetyl-2,3-dihydro-4H-1,4-thiazine

A new general synthetic route towards three key Maillard flavour compounds, namely 2-acetyl-1-pyrroline, 6-acetyl-1,2,3,4-tetrahydropyridine and 5-acetyl-2,3-dihydro-4H-1,4-thiazine, was developed. The key step in the process is the methylenation reaction of azaheterocyclic carboxylic esters by means of dimethyltitanocene, giving rise to intermediate vinyl ethers which can be considered as excellent and stable precursors for the title compounds, as a simple acidic treatment of these precursors suffices to release the characteristic Maillard flavours.

New short and general synthesis of three key Maillard flavour compounds: 2-Acetyl-1-pyrroline, 6-acetyl-1,2,3,4-tetrahydropyridine and 5-acetyl-2,3-dihydro-4H-1,4-thiazine

A new general synthetic route towards three key Maillard flavour compounds, namely 2-acetyl-1-pyrroline, 6-acetyl-1,2,3,4-tetrahydropyridine and 5-acetyl-2,3-dihydro-4H-1,4-thiazine, was developed. The key step in the process is the methylenation reaction of azaheterocyclic carboxylic esters by means of dimethyltitanocene, giving rise to intermediate vinyl ethers which can be considered as excellent and stable precursors for the title compounds, as a simple acidic treatment of these precursors suffices to release the characteristic Maillard flavours.

METHOD FOR SYNTHESISING 2-ACETYL-1-PYRROLINE AND THE STABLE PRECURSOR THEREOF, OPTIONALLY ISOTOPICALLY MARKED

The present invention relates to a method for synthetizing a compound of the following formula (I): wherein R is a methyl or ethyl group, n is 1 or 2, and X is a CH2 or CD2 group, from a compound of the following formula (II): wherein R and n are as defined above, and also relates to a method for assaying the compounds of the formula (I) using a corresponding deuterated derivative as an internal reference, as well as to the use of ketal derivatives of compounds of the formula (I) as a stable precursor, in particular in a flavoring composition.

A general method for the synthesis of the most powerful naturally?occurring Maillard flavors

The natural flavors 2-acetyl-1-pyrroline 1a, 2-propionyl-1-pyrroline 1b, 2-acetyl-3,4,5,6-tetrahydropyridine 1c, 2-acetyl-2-thiazoline 1d, 2-propionyl-2-thiazoline 1e, and the artificial flavor 2-acetyl-5,6-dihydro-4H-1,3-thiazine 1f have been prepared by catalytic SeO2 oxidation of the corresponding cyclic imines 6a-c and sulfur cyclic imines 7a-c using TBHP as co-oxidant. The oxidation of the pyrrolines 1a and b is completely regioselective. Professional olfactory evaluation together with the odor threshold of the new flavor 1f is reported.

δ1-pyrroline-5-carboxylic acid formed by proline dehydrogenase from the Bacillus subtilis ssp. natto expressed in Escherichia coli as a precursor for 2-acetyl-1-pyrroline

Proline dehydrogenase (PRODH) catalyzes the biosynthesis of Δ1-pyrroline-5-carboxylic acid (P5C). The Bacillus subtilis subsp. natto gene for the proline dehydrogenase (BnPRODH) was cloned and expressed in Escherichia coli. Nucleotide sequence analysis of the clone revealed an open-reading frame that encodes 302 amino acid polypeptide with a calculated molecular mass of 34.5 kDa. The deduced amino acid sequence showed sequence similarity to bacterial PRODH and PutA of E. coli. The BnPRODH gene was cloned into pET21b and was expressed at a high level in E. coli BL21-(DE3). The expressed protein was purified by using nickel ion affinity column chromatography to homogeneity before characterization. The purified recombinant BnPRODH was used to produce P5C. Model system composed of P5C and methylglyoxal was set up to study the formation of 2-acetyl-1-pyrroline. Our data showed that P5C, derived from the conversion of L-proline by the purified recombinant PRODH, might react directly with methylglyoxal to form 2-AP. P5C/methylglyoxal pathway represents the first report of a biological mechanism by which 2-AP may be synthesized in vitro by PRODH.

Process for the preparation of 2-acetyl-1-pyrroline, the basmati rice flavorant

The present invention provides a process for preparing of 2-acetyl-1-pyrroline, the principle aroma component of basmati and other varieties of scented rice, and also of processed cereal and grain products, said flavor chemical is of great value, in the art of application of flavor to foodstuffs like rice and bakery products.