Isoeugenol

A number of other valuable aroma chemicals can be isolated from essential oils, eg, eugenol from clove leaf oil, which can also, on treatment with strong caustic, be isomerked to isoeugenol, which on further chemical treatment can be converted to vanillin (qv). Sometimes the naturally occurring component does not requke prior isolation or concentration, as in the case of cinnamaldehyde in cassia oil which, on dkect treatment of the oil by a retro-aldol reaction, yields natural ben2aldehyde (qv). This product is purified by physical means. 

The manufacture of vanillin shows the progress made in the chemistry and chemical engineering of the substance. Most commercial vanillin is synthesized from guaiacol the remainder is obtained by processing waste sulfite Hquors. Preparation by oxidation of isoeugenol is of historical interest only. 

By direct oxidation by means of ozone, isoeugenol is converted into vanillin. 

Isoeugenol, when cooled to a very low temperature, crystallises in fine needles, which melt at 34°, but it usually exists in a state of superfusion. 

There are several crystalline compounds useful for the identification of isoeugenol, amongst which are the following —... 

Benzoyl-isoeugenol, melting at 105°, is prepared by the addition to 10 parts of isoeugenol of a dilute solution of caustic soda, and then of 16 parts of benzoyl chloride. The temperature should be kept low, and crystals of benzoyl-eugenol will separate. 

If equimolecular proportions of isoeugenol and acetic anhydride are heated for four to five hours to 135°, and the mixture washed with dilute alkali, acetyl-isoeugenol results, which, when dissolved in benzene and precipitated by petroleum ether, crystallises in needles melting at 79° to 80°. 

Isoeugenol, shaken with dimethyl sulphate and caustic potash, yields methyl-isoeugenol, which can be identified by its dibromide, melting at 101° to 102°. 

It is a useful adjunct in the manufacture of perfumes of the carnation type, modifying the odours of eugenol and isoeugenol to some extent. 

Methyl-isoeugenol, CjiHj O, bears exactly the same relationship to isoeugenol as methyl-eugenol does to eugenol. It occurs naturally in the oil of Asarum arifolium, and can be obtained by the action of methyl iodide on isoeugenol sodium, or by isomerising methyl-eugenol by hot alcoholic potash. 

Whilst safrol is the methylene ether of allyl-dioxy-benzene, isosafrol is the methylene ether of propenyl-dioxy-benzene, so that the two bodies are related to each other in the same, way as eugenol and isoeugenol. 

QHioO 493-05-0) see Ropinirole 2-isocyanatodiphenyIniethane (C14H11NO 146446-96-0) see Perlapine l-[3-isocyanato-4-(phenyImethoxy)phenyl)ethanone (CifiHijNOj 55057-75-5) see Carbuterol 6 3-isocyanopenicillanic acid benzyl ester (Ci HifjNjOjS 53628-27-6) see Temocillin isoeugenol... 

Zinke, T. Hahn, O. Uber die Einwirkung von Brom und von Chlor auf Phenole Substitutionsproducted, Pseudobromide and Pseudochloride IX. Uber die Einwirkung von Brom auf Isoeugenol. Justus Liebigs Ann. Chem. 1903, 329, 1-36. 

Chlorogenic acid forms a 1 1 complex with caffeine, which can be crystallized from aqueous alcohol and yields very little free caffeine on extraction with chloroform. Other compounds with which caffeine will complex in this way include isoeugenol, coumarin, indole-acetic acid, and anthocyanidin. The basis for this selection was the requirement for a substituted aromatic ring and a conjugated double bond in forming such a complex. This kind of complex does modify the physiological effects of caffeine.14 Complex formation will also increase the apparent aqueous solubility of caffeine in the presence of alkali benzoates, cinnamates, citrates, and salicylates.9... 

Note Tor, torulene LSO, hgnostilbene ISO, isoeugenol , full-length carotenoid cleavage , activity not known. 

Yamada, M., Y. Okada et al. (2007). Purification, characterization and gene cloning of isoeugenol-degrading enzyme from Pseudomonas putida IE27. Arch. Microbiol. 187(6) 511-517. 

Vanillin (4-hydroxy-3-methoxybenzaldehyde) is widely used in foods, beverages, perfumes and the pharmaceuticals industries. Biotransformation of isoeugenol from essential oil to vanillin represents an economic route for the supply of vanillin, which has a limited supply due to the availability of vanilli pod plants. The conversion yield of isoeugenol to vanillin by the whole-cell biotransformation process of Bacillus fusiformis was low due to the product inhibition effect. Adding resin HD-8 to the whole-cell biotransformation eliminated the product inhibition effect, yielding 8 gL 1 of vanillin in the final reaction mixture [27]. The resin HD-8 also facilitated the separation of vanillin from the used substrate. The recovered isoeugenol can be used for the subsequent biotransformation reaction. 

Zhao, L.-Q., Sun, Z.-H., Zheng, P. and He, J.-Y. (2006) Biotransformation of isoeugenol to vanillin by Bacillus fusiformis CGMCC1347 with the addition of resin HD-8. Process Biochemistry (Barking, London, England), 41, 1673-1676. 

Eugenol is a natural product available from a variety of essential oils (cinnamon-tree or pimentos leaves). Its isomerization (Eq. 49) into isoeugenol, the starting material for synthetic vanillin, is rather difficult and proceeds in modest yields under relatively harsh conditions. It can, however, be very efficiently prepared by use of 2.2 molar equivalents of base and catalytic (5 %) amounts of Aliquat in the absence of solvent. 

Eugenol undergoes MW-assisted isomerization to isoeugenol under solvent-free condition in the presence of potassium tert-butoxide, t-BuOK, and a catalytic amount of phase transfer reagent [34]. 

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