Eugenol acid

Teorell had done years before. The results showed that after the mucosa had been treated with eugenol, acid that was secreted in response to histamine stimulation disappeared by back-diffusion into the mucosa in exchange for sodium. The gastric mucosal barrier had been broken. 

If one is absolutely serious about ultra pure safrole then it can be separated from the eugenol-free sassafras oil by treatment with mercuric acetate [1,2,3,4] which likes that terminal double bond that only safrole has. The Hg(AcO)2 latches on to safrole at that double bond bringing it into solution as a solid sort of like the way that eugenol was. The safrole can then be separated from its still oily buddies by vacuum filtration. Safrole is then regenerated to its normal oily form by treatment with hydrochloric acid (HCI) which flicks the Hg(AcO)2 off the safrole and the safrole double bond reforms. As it so happens, the mercuric acetate also reforms intact so that it can be reused again such as in one of those... 

Using 28% acetic acid allows the eugenol, d-camphor and pinene to form its own top layer. There ivas no separation using 99.5% acetic acid. 

Added 112 grams sassafras oil. Shake for a couple of minutes. You get an orangish emulsion. Clears within 15 minutes forming two layers, bottom layer oil, top layer acetic acid, eugenol + the other solubles. Separated the oil from the others, washed the oil layer 2x with fresh C//-/2O. Weight after acetic acid water washes 101.5 (-10.5 grams). 

Other commonly occurring chemical groups ia essential oils iaclude aromatics such as P-phenethyl alcohol, eugenol, vanillin, ben2aldehyde, cinnamaldehyde, etc heterocycHcs such as iadole (qv), pyra2iaes, thia2oles, etc hydrocarbons (Liaear, branched, saturated, or unsaturated) oxygenated compounds such as alcohols, acids, aldehydes, ketones, ethers and macrocyclic compounds such as the macrocyclic musks, which can be both saturated and unsaturated. 

In paints, zinc oxide serves as a mildewstat and acid buffer as well as a pigment. The oxide also is a starting material for many zinc chemicals. The oxide supphes zinc in animal feeds and is a fertilizer supplement used in zinc-deficient soils. Its chemical action in cosmetics (qv) and dmgs is varied and complex but, based upon its fungicidal activity, it promotes wound healing. It is also essential in nutrition. Zinc oxide is used to prepare dental cements in combination with eugenol and phosphoric and poly(acrylic acid)s (48) (see Dental materials). 

This type of cement has been further improved by the substitution of -hexyl van ill ate [84375-71-3] and similar esters of vanillic acid [121 -34-6] and/or syringic acid [530-57 ] for eugenol (93—95). These substituted cements are strong, resistant to dissolution, and, unlike ZOE and EBA cements, do not inhibit the polymerization of resin-base materials. Noneugenol cements based on the acid—base reaction of zinc and similar oxides with carboxyhc acids have been investigated, and several promising types have been developed based on dimer and trimer acids (82). 

Calcium Chelates (Salicylates). Several successhil dental cements which use the formation of a calcium chelate system (96) were developed based on the reaction of calcium hydroxide [1305-62-0] and various phenohc esters of sahcyhc acid [69-72-7]. The calcium sahcylate [824-35-1] system offers certain advantages over the more widely used zinc oxide—eugenol system. These products are completely bland, antibacterial (97), facihtate the formation of reparative dentin, and do not retard the free-radical polymerization reaction of acryhc monomer systems. The principal deficiencies of this type of cement are its relatively high solubihty, relatively low strength, and low modulus. Less soluble and higher strength calcium-based cements based on dimer and trimer acid have been reported (82). 

A synthesis of possible biological significance was effected by Spath and Berger, who ozonised eugenol methyl ether to 3 4-dimethoxyphenyl-acetaldehyde (Villa), which was then condensed with 3 4-dimethoxy-phenylethylamine (Vlllb), and the resulting Schiff s base (IX) treated wit hot 19 per cent, hydrochloric acid, whereby it was transformed into... 

Euruka wa t lnds eugenol and probably chavicol. atid i races of citron cl lie acid in Jftva citiOiii Ua oh. 

Tboros and Beekstroem Isolated n-hepiylic acid, palmitic acid, an unreoogn 1 sed unaaturated acid, eugenol, aud asarjlic aldehyde. There is also prusent a body ul the formula inultiiig at 128 , which... 

By methylation with dimethyl sulphate and potash, it yields methyl-eugenol, boiling at 248° to 249° and which on oxidation yields veratric acid, melting at 179° to 180°. 

The principal derivative for identification purposes is veratric acid, C H.,(C00H)(0CH3)2, which is obtained by oxidising 6 grams of methyl-eugenol with a solution of 18 grams of potassium permanganate in 400 c.c. of water. When recrystallised from alcohol, veratric acid melts at 179° to 180°. 

Nelke,/. clove pink (the flower). Nelken-gewachse, n.pl. (Boi.) Caryophylla-ceae. -kassie, /. clove cassia, -ol, n. clove oil, oil of cloves, -pfeffer, m. allspice, pimento, -pfefferwasser, n. (Pharm.) pimento water, -rinde, /. clove cassia, -s ure, /. eugenol caryophyllic acid, -stein, m. iolite. -wurzel, /. avens root. -zim(m)t, m. clove cinnamon, clove cassia. 

In the 1870s more effective liquid cement-formers were found ortho-phosphoric acid and eugenol (Wilson, 1978). It was also found that an aluminosilicate glass could replace zinc oxide, a discovery which led to the first translucent cement. Thereafter the subject stagnated until the late 1960s when the polyelectrolyte cements were discovered by Smith (1968) and Wilson Kent (1971). 

The Arrhenius definition is not suitable for AB cements for several reasons. It cannot be applied to zinc oxide eugenol cements, for these are non-aqueous, nor to the metal oxychloride and oxysulphate cements, where the acid component is not a protonic acid. Indeed, the theory is, strictly speaking, not applicable at all to AB cements where the base is not a water-soluble hydroxide but either an insoluble oxide or a silicate. 

This concept covers most situations in the theory of AB cements. Cements based on aqueous solutions of phosphoric acid and poly(acrylic acid), and non-aqueous cements based on eugenol, alike fall within this definition. However, the theory does not, unfortunately, recognize salt formation as a criterion of an acid-base reaction, and the matrices of AB cements are conveniently described as salts. It is also uncertain whether it covers the metal oxide/metal halide or sulphate cements. Bare cations are not recognized as acids in the Bronsted-Lowry theory, but hydrated... 

Related to these cements are the long chain aliphatic acids and aryl-substituted butyric acid (Skinner, Molnar Suarez, 1964). These materials are on the market as non-eugenol cementing agents but they are unduly... 

Cement formation is the result of an acid-base reaction between zinc oxide and eugenol, leading to the formation of a zinc eugenolate chelate. Water plays a vital role in the reaction. 

Eugenol is a very weak acid (p = 10-4) and will not react with zinc oxide in the absence of promoters. These reaction promoters include water, acetic acid and zinc acetate. 

Figure 9.3b Conductivity/time curves (a) of cements, showing maxima. Prepared from ZnO ignited at 600 C with A-.-A dry eugenol 0...0 eugenol + 1% water O-.-O eugenol + 1% chloracetic acid ... eugenol+1% acetic acid ... eugenol+1% acetic acid+1% water. Cement powder/liquid ratio = 2-5 g cm (Crisp, Ambersley Wilson, 1980).

This scheme applies only to the reaction in simple zinc oxide and eugenol systems. The presence of an accelerator such as zinc acetate profoundly modifies it. The addition of Zn + ions or acetic acid (HAc) to the system eliminates the need for water to initiate the reaction. The reactions can then be represented by the following series of equations. 

The term EBA cement is not quite exact, but is convenient to use and has been generally accepted. Originally this cement was a variant of the ZOE cement - its most important variant - and was based on a liquid which was a mixture of 2-ethoxybenzoic acid (EBA) and eugenol. More recently, eugenol has been replaced by other compounds of similar structure. All these cements contain EBA as a major constituent. 

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