Saponification naturally occurring

The alkali in these water pools reacts with organic matter such as algae and moss growing on the stone. The most common of these reactions is saponification (see p. 240), which causes naturally occurring esters to split, to form the respective carboxylic acid and an alcohol. Once formed, this carboxylic acid reacts with more alkaline rainwater to form a metal carboxylate, according to... 

Saponification of stevioside with a strong alkaline base yielded steviol-bioside. Although steviolbioside has been identified in some S. rebaudiana extracts, it is generally thought to be an artifact of extraction or isolation procedures rather than a naturally occurring glycoside. ... 

BASIC PROTOCOL I PREPARATION OF FATTY ACID METHYL ESTERS FROM LIPID SAMPLES CATALYZED WITH BORON TRIFLUORIDE IN METHANOL In this method, lipid samples are first saponified with an excess of NaOH in methanol. Liberated fatty acids are then methylated in the presence of BF3 in methanol. The resulting fatty acid methyl esters (FAMEs) are extracted with an organic solvent (isooctane or hexane), and then sealed in GC sample vials for analysis. Because of the acidic condition and high temperature (100°C) used in the process, isomerization will occur to those fatty acids containing conjugated dienes, such as in dairy and ruminant meat products, that contain conjugated linoleic acids (CLA). If CLA isomers are of interest in the analysis, Basic Protocol 2 or the Alternate Protocol should be used instead. Based on experience, this method underestimates the amount of the naturally occurring cis-9, trans-11 CLA isomer by -10%. The formulas for the chemical reactions involved in this protocol are outlined in Equation D1.2.1 Saponification RCOO-R + NaOH, RCOO-Na + R -OH v 100°C DC Esterification RCOO-Na + CH,OH r 3 v RCOO-CH, + NaOH ioo°c ... 

In the analysis of foods that contain significant amounts of both naturally occurring toco-pherols and supplemental a-tocopheryl acetate, saponification, by hydrolyzing the esterified vitamin E, allows the total a-tocopherol content to be measured as a single peak by HPLC. It should be noted that if totally synthetic all-rac-a-tocopheryl acetate is the supplemental form used, its hydrolysis product, all-rac-a-tocopherol, is less biologically active than is naturally occurring RRR-a-tocopherol, making it impossible to calculate a potency value for the total vitamin E. This problem does not arise if the supplement used is / / / -a-tocopheryl acetate. 

The most important reaction of esters is their conversion by a carbonyl-group substitution reaction into carboxylic acids. Both in the laboratory and in the body, esters undergo a reaction with water—a hydrolysis—that splits the ester molecule into a carboxylic acid and an alcohol. The net effect is a substitution of -OC by -OH. Although the reaction is slow in pure water, it is catalyzed by both acid and base. Base-catalyzed ester hydrolysis is often called saponification, from the Latin word sapo meaning "soap." Soap, in fact, is a mixture of sodium salts of long-chain carboxylic acids and is produced by hydrolysis with aqueous NaOH of the naturally occurring esters in animal fat. 

Saponification.—As we shall see later, this is the kind of reaction which takes place when soap is made from fats and on that account it is termed an action of saponifikation. In this way the acids are obtained as salts from the naturally occurring fats, oils and waxes in which they are present in the form of esters. The hydrolysis of esters or ethereal salts is then the general reaction by which, with the taking up of the elements of water, an ester is reconverted into the two compounds from which it was formed, viz., into an acid and an alcohol. Esterification and hydrolysis or saponification are, therefore, complementary names applying to the reversible reaction effecting the synthesis and decomposition of esters. The reversible character of the reactions of esterification and... 

Following reduction in volume of the extracting solvent under nitrogen, subsequent saponification and re-esterification is required prior to chromatographic separations of the mixture. After saponification no distinction is possible between free acids and their naturally occurring esters. Only direct GC—MS of the crude extract would allow any estimations of the amounts of free esters present in the sample. 

Acetonide 141 has also been used in a short synthesis of (— )-tulipalin B (148), a naturally occurring lactone with cutaneous allergenic activity (Scheme 19) [22]. Methylenation of 141 is accomplished by treatment of the enolate anion with Eschenmoser salt, followed by per-methylation and elimination of the resulting trimethylammonium salt. Unfortunately, the yield is rather low, but unreacted 141 can be recovered in 80% yield. Saponification of the ester and subsequent acid-catalyzed deprotection with concomitant lactonization furnishes 148. 

Naturally occurring (l S, 25, 3i )-4-hydroxymethylcyclopent-4-ene-l,2,3--triol (950) plays a central role in the ability of a non-aristeromycin producing mutant strain of Streptomyces citricolor to support production of both aristeromycin and neplanocin. Swem oxidation of readily available 13 from L-tartaric acid provides the aldehyde 943 which, when treated with an excess of propargyl zinc bromide, leads to a 2.3 1 diastereomeric mixture of acetylenic alcohols 944. Silylation of the hydroxyl group with TBSOTf and subsequent saponification of the ester group yields the carboxylic acid 945 in 74% overall yield from 13. Interestingly, Dess-Martin oxidation of 943 provides the allenic ketone 946, which is unstable to base and cannot be used in the subsequent radical cyclizations. 

The hydrolysis of an ester in the presence of a base is called saponification, a term that comes from the Latin word for soap, sapon. Naturally occurring esters include fats and oils, and in making soap an animal fat or a vegetable oil is boiled with a strong base. The resultant soap consists of a mixture of salts of long-chain carboxylic acids (called fatty adds), which form during the saponification reaction. (Section 13.6)... 

In the field of carotenoids, most TLC-MS utilizations to date have been made offline and have used TLC merely for the purpose of purification or isolation of these pigments. Mass spectrometry was introduced into carotenoid analysis in 1965 [16]. In the 1970s, separations by open column chromatography on aluminum oxide were often combined with TLC separations on silica gel and MgO/Kieselguhr to achieve sufficient purification degree of carotenoids from tomato. These were analyzed afterward by direct-insertion electron impact-MS (EI-MS) [17-19]. Such isolation procedures, applied reactions (acetylation, saponification, and reduction), Rf values, absorption, and MS spectra enabled identification of phytoene 1,2-oxide, and related compounds as the first naturally occurring epoxides of acyclic carotenoids [17]. 

Naturally occurring lipid mixtures have a composition of such extreme complexity that the analysis by chemical methods of a group of these substances or the determination of a single compound in such mixtures, appears hopeless. Up to about ten years ago, lipid mixtures were characterised by totals like acid-, saponification-, iodine-, thio-cyanogen- and diene- numbers . The determination of the amount of non-saponifiable matter after alkaline hydrolysis was a standard method in the analysis of fats. Phospholipids and sulpholipids were quantitatively determined as inorganic phosphate and sulphate after combustion. These methods were supplemented by detection of subsidiary fat constituents like lipochromes, sterols and resin acids, with the help of colour reactions. 

Glycerine esters of Laurie acid are an essential part of Laurie oil which naturally occurs, e.g. in palm-oil and coco-nutoil the latter contain in contrary to other plant-oils high amounts of glyceryl laureates (40-50%) and are used for the production of Laurie acid by saponification, followed by destination. The antimicrobial acitivity of Laurie acid is negligible. The acid is mentioned here, as it is part of the microbicide Lauricidin (9.8. = glyceryl monolaurate). 

Esters are derived from carboxylic acids by reaction with alcohols. They have a wide variety of applications ranging from flavouring agents to solvents and explosives. One of the most used painkillers in medication, aspirin, is an ester, while a major class of polymers are the poly(esters). Fats and vegetable oils are naturally occurring esters and the alkaline hydrolysis of such esters (saponification) is used to produce soaps. 

Sesame oil contains sufficient naturally occurring phenolic bodies to interfere and a correction must be applied to the colorimetric reading for the colour due to the oil. The method is liable to give low results but increasing the time of saponification improves the recovery. 

Provitamin D. Provitamin is made from cholesterol, and its commercial production begias with the isolation of cholesterol from one of its natural sources. Cholesterol occurs ia many animals, and is generally extracted from wool grease obtained by washing wool after it is sheared from sheep. This grease is a mixture of fatty-acid esters, which contain ca 15 wt % cholesterol. The alcohol fraction is obtained after saponification, and the cholesterol is separated, usually by complexation with 2iac chloride, followed by decomplexation and crystallisation. Cholesterol can also be extracted from the spiaal cords and brains of animals, especially catde, and from fish oils. 

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