Pineapple ketone

If only a few specific components need be quantified, the analysis time can be considerably shortened. Dong and DICesare (50) developed an high speed isocratic reverse phase separation for 2,5-dimethyl-4-hydroxy-3(2H)-furanone. This compound is commonly known as pineapple ketone and can be quantified in food flavoring products using one of the new 3x3, C-18 columns in as little as 2 minutes. Other workers (51J have used rapid gradients (6 min.) to separate caffeine, trigonelle and theobromine in coffee and cocoa products. 

It has been demonstrated that the racemic natural product 4-hydroxy-2,5-dimethylfuran-3(2//)-one (HDMF, furaneol, pineapple ketone) 75 probably is formed by in vivo racemization of a biosynthetically formed enantiomer. Biosynthesis at pH 5 leads to enantiomerically enriched 75. At pH 7.2, 50% of the C-2 hydrogen atoms are exchanged with D2O within 1 h <2003CH573>. 

Cyclopentenolones with a planar vicinal enol-oxo configuration are known to be powerful aroma active substances with distinct caramel notes. By methylation of the enolic function, this flavour impression is changed drastically to a sweet, mildew, and mouldy odour in the case of 2,5-dimethyl-4-methoxy-3-[2H]-furanone (2). This so-called mesifurane as well as pineapple ketone (1) were stereodifferentiated with modified cyclodextrin [103], Although (1) and (2) can be stereoanalyzed without any racemization, both compounds were detected in strawberries, pineapples, grapes and wines as racemates (Fig. 6.43). 

Synonyms Alletone Alnose Dimethylhydroxy furanone 2,5-Dimethyl-4-hydroxy-3-furanone 2,5-Dimethyl-4-hydroxy-3-(2H)-furanone Furaneol 3(2H)-Furanone, 2,5-dimethyl-4-hydroxy- Pineapple ketone Strawberry furanone... 

Pineapple ketone. See 4-Hydroxy-2,5-dimethyl-3(2H) furanone Pine balsam. See Turpentine Pine bark, white. See Pine (Pinus strobus) bark Pine gum. See Turpentine Pine lignin CAS 37203-80-8 Synonyms Kraft pine lignin Properties Anionic... 

Capillary gas chromatographic determination of optical purities, investigation of the conversion of potential precursors, and characterization of enzymes catalyzing these reactions were applied to study the biogenesis of chiral volatiles in plants and microorganisms. Major pineapple constituents are present as mixtures of enantiomers. Reductions, chain elongation, and hydration were shown to be involved in the biosynthesis of hydroxy acid esters and lactones. Reduction of methyl ketones and subsequent enantioselective metabolization by Penicillium citrinum were studied as model reactions to rationalize ratios of enantiomers of secondary alcohols in natural systems. The formation of optically pure enantiomers of aliphatic secondary alcohols and hydroxy acid esters using oxidoreductases from baker s yeast was demonstrated. 

Pineapple Allyl caproate, Methyl-(3-methylthiopropionate Popcorn 2-Acetyl-1 -py rroli ne methyl-2-py ridyl ketone... 

Pineapple Ananas comosus, Bromeliaceae) aroma consists of about 200 alcohols, esters, lactones, aldehydes, ketones, monoterpenes, sesquiterpenes and other volatiles. About 80% of the total volatile substances are esters. The main components in the green fruit are ethyl acetate, ethyl 3-(methylthio)propionate (8-189) with a distinctive pineapple aroma and ethyl 3-(acetoxy)hexanoate (8-190). The ripe fruit contains, as the main esters, ethyl acetate, (2J ,3i )-butane-2,3-diol diacetate (8-191) and ketone 3-hydroxy-butan-2-one. An important compound for the typical character of pineapple aroma, as in strawberry aroma, is 2,5-dimethyl-4-hydroxy-2//-furan-3-one (furaneol), present as a glycoside, and 2,5-dimethyl-4-methoxy-2H-furan-3-one. 

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