Esters isoamyl acetate

Acetic acid, 3-methylbutyl ester isoamyl acetate CH3-C00-(CH2)2-CH=(CH3)2 172a 174a, 174b, 603, 3370... 

Isoamyl acetate is the common name of the substance most responsible for the characteris tic odor of bananas Wnte a structural formula for isoamyl acetate given the information that it IS an ester in which the carbonyl group bears a methyl substituent and there is a 3 methylbutyl group attached to one of the oxygens... 

The acetates of most alcohols are also commercially available and have diverse uses. Because of their high solvent power, ethyl, isopropyl, butyl, isobutyl, amyl, and isoamyl acetates are used in ceUulose nitrate and other lacquer-type coatings (see Cellulose, esters). Butyl and hexyl acetates are exceUent solvents for polyurethane coating systems (see Coatings Urethane polymers). Ethyl, isobutyl, amyl, and isoamyl acetates are frequentiy used as components in flavoring (see Flavors and spices), and isopropyl, benzyl, octyl, geranyl, linalyl, and methyl acetates are important additives in perfumes (qv). 

Acetic acid, 2-ethoxyethyl ester, see 2-Ethoxyethyl acetate Acetic acid, ethylene ester, see Vinyl acetate Acetic acid, ethyl ester, see Ethyl acetate Acetic acid, isobutyl ester, see Isobutyl acetate Acetic acid, isopentyl ester, see Isoamyl acetate Acetic acid, isopropyl ester, see Isopropyl acetate Acetic acid, 2-methoxyethyl ester, see Methyl cellosolve acetate... 

Acetic acid, 3-methylbutyl ester, see Isoamyl acetate... 

Indenopyrene, see Indeno[l,2,3-crf pyrene l//-Indole, see Indole Indolene, see Indoline Inexit, see Lindane Inhibisol, see 1,1,1-Trichloroethane Insecticide 497, see Dieldrin Insecticide 4049, see Malathion Insectophene, see a-Endosulfan, p-Endosulfan Intox 8, see Chlordane Inverton 245, see 2,4,5-T lodomethane, see Methyl iodide IP, see Indeno[l,2,3-crf pyrene IP3, see Isoamyl alcohol Ipaner, see 2,4-D IPE, see Isopropyl ether IPH, see Phenol Ipersan, see Trifluralin Iphanon, see Camphor Isceon 11, see Trichlorofluoromethane Isceon 122, see Dichlorodifluoromethane Iscobrome, see Methyl bromide Iscobrome D, see Ethylene dibromide Isoacetophorone, see Isophorone a-Isoamylene, see 3-Methyl-l-butene Isoamyl ethanoate, see Isoamyl acetate Isoamylhydride, see 2-Methylbutane Isoamylol, see Isoamyl alcohol Isobac, see 2,4-Dichlorophenol Isobenzofuran-l,3-dione, see Phthalic anhydride 1,3-Isobenzofurandione, see Phthalic anhydride IsoBuAc, see Isobutyl acetate IsoBuBz, see Isobutylbenzene Isobutane, see 2-Methylpropane Isobutanol, see Isobutyl alcohol Isobutene, see 2-Methylpropene Isobutenyl methyl ketone, see Mesityl oxide Isobutyl carbinol, see Isoamyl alcohol Isobutylene, see 2-Methylpropene Isobutylethylene, see 4-Methyl-l-pentene Isobutyl ketone, see Diisobutyl ketone Isobutyl methyl ketone, see 4-Methyl-2-pentanone Isobutyltrimethylmethane, see 2,2,4-Trimethylpentane Isocumene, see Propylbenzene Isocyanatomethane, see Methyl isocyanate Isocyanic acid, methyl ester, see Methyl isocyanate Isocyanic acid, methylphenylene ester, see 2,4-Toluene-diisocyanate... 

Esters also constitute a group of important flavour compounds. They are the main aroma components found in fruits (apples, pears,. ..). For example, bananas contain 12-18 ppm acetates. The price of the pure flavour compounds, when isolated from fruit, can range between 10,000 and 100,000 US /kg In the past, research has been carried out by our group about the microbial production of fruity esters by the yeast Hansenula mrakii and the fungus Geotrichum penicillatum [10]. A fermentation was developed whereby fusel oil was continuously converted into a mixture of 3-methylbutyl acetate (isoamyl acetate) and 2-methylbutyl acetate, the character impact compounds of banana flavour. 

Amyl Acetate or Amylacetic Ester(commonly known as Banana Oil),C5 Htl.COOCH mw 130.18- Several isomers are known of which n-amyl acetate and isoamyl acetate are the most important. They can be prepd by heating amyl alcohols with acetic acid in the presence of some sulfuric acid. Industrial methods of prepn are given in Ref 9,pp 102—3- Commercial products are usually mixts of n- and iso-amyl acetates. When amyl acetate is prepd from "fusel oil (a byproduct obtained in the raanuf of ethyl ale by fermentation), the chief component is isoamyl acetate... 

Ethyl hexanoate and octanoate were the predominant FA esters found in Tinta Negra wines, whereas diethyl succinate and ethyl lactate were the most abundant diprotic acid ethyl esters. According to the authors, the most sensory important flavors seem to be attributed to 3-methylbutan-l-ol, 2-phenylethanol, isoamyl acetate, diethyl succinate, 2-phenylethylace-tate, phenylacetaldehyde, y-nonalactone, ethyl hexanoate, ethyl octanoate, hexanoic acid, and octanoic acid. 

Some examples of naturally occurring esters and amides are shown here. Isoamyl acetate gives ripe bananas their characteristic odor, and geranyl acetate is found in the... 

Esters are among the most common acid derivatives. They are found in plant oils, where they give the fruity aromas we associate with ripeness. For example, the odor of ripe oil ITIITI3 ry OT thG bananas comes mostly from isoamyl acetate. Oil of wintergreen contains methyl sali- ChGlTI istfV Of Esters... 

The impact of a compound cannot be predicted from its OAV value, but is the result of the interaction of the odorant with the other odorants present in the mixture. In general, experience has shown that impact compounds, whenever they exist, are odorants present at concentrations higher than the threshold and showing, usually, an odor quite different from the rest of odors present in the wine and demonstrating a personal character. For instance, out of all fruity esters of wine, only isoamyl acetate and phenylethyl acetate, both of which have clear specific and differentiable aromas, have been found to be able to act as impact compounds (Van Wyk et al. 1979 Tat et al. 2007). Similarly, the three mercaptans derived from cysteine, 4-methyl-4-mercaptopentan-2-one, 3-mercaptohexanol and 3-mercaptohexyl acetate, all of which have specific aromas, have been found to be key compounds in some wines (Darriet et al. 1995 Murat et al. 2001 Ferreira et al. 2002a Campo et al. 2005). 

Differences in ester production have been consistently found among yeast strains (31,33,37-39,41-43). As was noted above the lack of inter-study replication lessens the ability to ascertain validity furthermore, the values reported for individual esters can vary widely among studies. Results for isoamyl acetate are presented in Table II. 

Soles et al. (42) found the same situation to be true with regards to ester production. Meilgaard (53) reported a detection threshold for isoamyl acetate in beer of. 5 mg/L. Given that nine of the fourteen yeasts studied by Soles et al (42) produced between 1.5 and 2 mg/L of isoamyl acetate (and all produced less than 3 mg/L), it is doubtful that the differences among the strains would be of practical sensory significance. 

Esters are colorless, volatile liquids that often have pleasant odors. Many occur naturally in flowers and fruits. Isoamyl acetate (Fig. 7.27a) is generated in apples as they ripen and contributes to the flavor and odor of the fruit. Benzyl acetate, the ester formed from acetic acid and benzyl alcohol (see Fig. 7.27b), is a major component of oil of jasmine and is used in the preparation of perfumes. 

Acetate Esters Methyl acetate Ethyl acetate Propyl acetate Isopropyl acetate Butyl acetate Isobutyl acetate Amyl acetate Isoamyl acetate (banana Vinyl acetate Methyl vinyl acetate Benzyl acetate Cyclohexyl acetate... 

Iodine Potassium Iodide Dodecylbenzene Tridecyibenzene Hydroquinone Propionaldehyde Methylform amide Diacetone Alcohol Isoamyl Alcohol Pentanedione (2,4-) Acetylacetone Paraldehyde Butylaldehyde Butyraldehyde Levulinic Acid Dioctyl Adipate Acetic Acid Butyl Ester Butyl Acetate Dioxane (1,4-) Dioxane Dioxane (p-) Isoamyl Acetate Thiodiacetic Acid Butyl Stearate Santoprene 201-73 Kamax T-260 Adipic Acid Ethylene Chloroformate Caprylic Acid Octanoic Acid Hexamethylenediamine Butyl Carbitol Acetate Decane Carbon Dioxide Dimethylamine Sodium Methylate Freon 114B2 Tetrachloropentane Santicizer 141 Santoprene 201-64 Ecolan Hetron 99P Calcium Hydride Triton Sulfolane Tributyl Phosphate Tributylphosphate Sodium Diacetate Methacrylonitrile... 

Among esters, compounds relevant in the characterization of the fruity aroma of wine are isoamyl acetate, hexyl acetate, 2-phenylethyl acetate and the ethyl esters of the hexanoic, octanoic and decanoic acids. Diethyl succinate is considered as an index of wine ageing and bacterial activity. For all these compounds and the corresponding fatty acids, there is a good linear correlation between XAD-2 enrichment and Kaltron liquid-liquid extraction. A little higher extraction, related to the internal standard, of Kaltron with respect to XAD-2 resin is obtained for most esters and acids, but not for the diethyl succinate and the... 

In addition to diacetyl, O. oeni produces esters, flavor compounds also important for wine flavor and aroma. Esters are primarily produced by Saccharomyces during alcoholic fermentation (Mason and Dufour, 2000 Nykanen, 1986 Nykanen and Nykanen, 1977 Soles et al., 1982), although evidence shows that esters such as ethyl acetate, ethyl lactate, ethyl hexano-ate, and ethyl octanoate can be synthesized by O. oeni (De Revel et al., 1999 Delaquis-Pascal et al., 2000 Edwards and Peterson, 1994 Maicas et al., 1999 Tracey and Britz, 1989). For example, Edwards and Peterson (1994) reported that strains of O. oeni synthesized relatively large amounts of ethyl lactate (183-1280 /ig/L) during growth in microbiological medium. In agreement, Maicas et al. (1999) reported that 50 mg/L of ethyl lactate was produced in wines fermented with O. oeni, as well as isoamyl acetate and ethyl caproate, compounds important for a pleasant fruity note in wine (Gil et al., 1996 Mason and Dufour, 2000 Nykanen, 1986). 

The production of the higher alcohols, the acetates of isoamyl alcohol and phenylethyl alcohol, and the ethyl esters of the C6-C10 fatty acids has been studied in semiaerobic sugar fermentations by strains of . cerevisiae and S. uvarum. S. cerevisiae generally produced more esters than S. uvarum. Isoamyl acetate was the main ester produced by >. cerevisiae. and others, in decreasing order, were ethyl caprylate, ethyl caproate, ethyl caprate and phenylethyl acetate(39). Several unusual thio compounds have been produced by Saccharomvces in model anaerobic fermentations using amino acids such as methionine as the sole carbon source(21). These model fermentations produce methylthiopropanal and traces of other sulfur containing compounds, such as methionyl acetate and 2-methyltetrahydrothiophene-3-one. 

Esters are mildly polar and have pleasant aromas. Many esters are found in natural foodstuffs banana oil (3-methylbutyl ethanoate common name, isoamyl acetate), pineapples (ethyl butanoate common name, ethyl butyrate), and raspberries (isobutyl methanoate common name, isobutyl formate) are but a few... 

Mandelic Acid Isoamyl Ester, a-Hydroxybenzene-acetic acid 3-methylbutyl ester mandelic acid isopentyl ester isoamyl mandelate Atractyl Spasmol Mandaverm Vermi-parin Spasmostenyl. C,jH,Oj mol wt 222.27. C 70.24%, H 8.16%, O 21.59%. Prepd by esterification of dl-mandelic acid with an excess of isoamyl alcohol in the presence of coned H]SO( Rona et al, Biochem. Z. 181, 50 (1927). Improved procedure Brock et al, Arzneimittel-Forsch. 2, 166 (1952). 

Amyl Acetate Amyl Nitrite Cyanoacrylate Ethyl Acetate Isoamyl Acetate L-Aspartyl-L-Phenylalanine Methyl Ester Nitroglycerin... 

SYNONYMS banana oil, isoamyl ethanoate, isopentyl acetate, 3-methyl-1-butanol acetate, 3-methylbutyl ester of acetic acid, 3-methylbutyl ethanoate. 

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