Myristate esters

Cholesteryl myristate [1989-52-2] M 597,0, m 69-71°, [a] -25.4° (c 1, CHCI3). Crystallise the myristate ester from Me2CO, EtOH/EtOAc or EtOH/Et20 or n-pentanol. Purify it also by column chromatography on silica gel and eluting with MeOH then evaporating to dryness. Recrystallise it and finally, dry it in vacuo over P2O5 and store it at -20°. [Labariere et al. Analyt Chem 30 1466 1958, Malanik Malat Anal Chim Acta 76 464 1975, Beilstein 6 III 2638]. 

More recently Webb et al. (1952) reported no isopropyl alcohol in a wine fusel oil sample. They did find 4.1% n-propyl, 1.9% n-butyl, 4.9% ( — )-sec-butyl, 18.3% isobutyl, 9.6% ( —)-2-methyl-l-butanol, 54% isoamyl, trace of n-amyl, 1.5% n-hexyl, 5.6% esters, and traces of acetic and butyric acids and acetal. The esters included 0.19% ethyl caproate, 0.60% ethyl caprylate, 0.52% isoamyl caprylate, 1.32% ethyl caprate, 0.38% isobutyl caprate, 0.58% ethyl laurate, 0.25% ethyl palmitate, a trace of butyrate ester, 0.06% myristate ester. Probably present were methyl salicylate, isoamyl caprate, active amyl caproate, isoamyl caproate, active amyl caprylate, isobutyl caprylate, active amyl caprate, active amyl laurate, and isoamyl laurate. 

Cleavage of the trityl ether from the Manlll with formic acid followed by the phos-phitylation with phosphoramidite 25 and meto-chloroperoxybenzoic acid (m-CPBA) oxidation at —40°C gave phosphotriester 39 as a 1 1 mixture of diastereomers. Upon removing the cyclohexanone ketal from the inositol, the corresponding diol was converted into an orthoester using the trimethyl orthoester of myristic acid. Hydrolysis of the orthoester in the presence of Yb(OTf)3 installed the myristate ester... 

By increasing the molar proportion of the monocarboxylic acid, the yield of (II) is improved. Thus electrolysis of a mixture of decanoic acid (n-decoic acid capric acid) (V) (2 mols) and methyl hydrogen adipate (VI) (1 mol) in anhydrous methanol in the presence of a little sodium methoxide gives, after hydrolysis of the esters formed, n-octadecane (VII), tetradecanoic or myristic acid (VIH) and sebacic acid (IX) ... 

Some fixed oils, such as cottonseed oil or peanut oil, and esters, eg, isopropyl myristate, may be used as solvent systems for parenteral dmgs. 

Bayberry Wax. Bayberry wax [8038-77-5] is removed from the surface of the berry of the bayberry (myrtle) shmb by boiling the berries in water and skimming the wax from the surface of the water. The wax is green and made up primarily of lauric, myristic, and palmitic acid esters. The wax has a melting point of 45°C, an acid number of 15, a saponification number of 220, and an iodine number of 6. The wax has an aromatic odor and is used primarily in the manufacture of candles and other products where the distinctive odor is desirable. 

Myristic acid occurs as a glyceride in many vegetable fats and oils, in particular in coconut oil,i its isolation from which involves separation from homologs by fractional distillation of the acids or their esters. The trimyristin obtained from nutmegs 2 (p. 100) or from the seeds of Virola venezuelensis forms the most suitable source. 

Myristic acid (tetradecanoic acid) [544-63-8] M 228.4, m 58 , pK 6.3 (50% EtOH), pK si -4.9 (H2O). Purified via the methyl ester (h 153-154 /10mm, n 1.4350), as for capric acid. [Trachtman and Miller y/4m Chem Soc 84 4828 7962.] Also purified by zone melting. Crystd from pet ether and dried in a vacuum desiccator containing shredded wax. 

A variety of cellular and viral proteins contain fatty acids covalently bound via ester linkages to the side chains of cysteine and sometimes to serine or threonine residues within a polypeptide chain (Figure 9.18). This type of fatty acyl chain linkage has a broader fatty acid specificity than A myristoylation. Myristate, palmitate, stearate, and oleate can all be esterified in this way, with the Cjg and Cjg chain lengths being most commonly found. Proteins anchored to membranes via fatty acyl thioesters include G-protein-coupled receptors, the surface glycoproteins of several viruses, and the transferrin receptor protein. 

About 50% of isopropanol use is to produce acetone. Other important synthetic uses are to produce esters of many acids, such as acetic (isopropyl acetate, solvent for cellulose nitrate), myristic, and oleic acids (used in lipsticks and lubricants). Isopropylpalmitate is used as an emulsifier for cosmetic materials. Isopropyl alcohol is a solvent for alkaloids, essential oils, and cellulose derivatives. 

Myristic Acid (Coll. Vol. 1, 371) An improved apparatus for fractionation of the methyl esters from coconut oil. Lepkovsky, Feskov, and Evans, J. Am. Chem. Soc. 58, 978 (1936). 

Most of the technically produced a-sulfo fatty esters are prepared from unbranched saturated fatty acid esters that are derived from 8 22 carboxylic acids and Cj-C3 alcohols. In particular the C12 (lauric), C14 (myristic), C16 (palmitic), and C18 (stearic) acids are interesting because the ester sulfonates... 

Fujiwara et al. studied the precipitation phase boundary diagrams of the sodium salts of a-sulfonated myristic and palmitic acid methyl esters in the presence of calcium ions [61]. The time dependency of the precipitation showed that the calcium salts have an extremely slow crystallization rate at room temperatures. This is the reason for the good hardness tolerance of the a-sulfonated fatty acid methyl esters. 

A soap-based powder can be produced in combination with ester sulfonates. Thirty-five percent of a sodium soap mixture (5% lauric acid, 5% myristic acid, 52% palmitic acid, 21% stearic acid, 12% oleic acid, and 5% linoleic acid) is mixed with 15% sodium a-sulfo palm oil fatty acid methyl ester, 3% lauric acid ethoxylate, 5% sodium silicate, 17% sodium carbonate, 20% Na2S04- 10H2O, and 5% water [79]. 

C2-C4 w-alkanes [42,43], and in supercritical carbon dioxide when employing novel surfactants with fluorocarbon tails [38,44], There is also interest in the further employment of lipids (triglycerides and wax esters, such as isopropyl myristate) as solvent to improve biocompatibility [45],... 

The oleaginous phases of creams differ composi-tionally from hydrocarbon ointments. Many, but not all, creams are patterned after vanishing cream and contain considerable stearic acid. In lieu of some or all of the stearic acid, creams sometime contain long-chain waxy alcohols (cetyl, Ci6 stearyl, Ci8), long-chain esters (myristates, Ci4 palmitates, Ci6 stearates, Cig), other long-chain acids (palmatic acid), vegetable and animal oils, and assorted other waxes of both animal and mineral origin. 

Alternatively, a sequence of pervaporation steps can be used to remove the reaction water (Figure 4.10). The reaction solution is pumped through a first fixed-bed reactor and afterwards a pervaporation module is used to remove the water at 80 °C. The solution is subsequently cooled to 60 °C and passed through a second reactor unit. After the next pervaporation step the water content is lowered to 0.2 wt%. By this process, isopropyl myristate is produced from myristyric acid. This and other esters of isopropyl alcohol are used in soaps, skin creams, lubricants and greases [43],... 

The slow water removal is obvious within the synthesis of, for example, myristyl myristate determining the total reaction time. In a stirred-tank reactor it takes 24 h to reach a conversion of 99.6% and in a fixed-bed reactor 14 h. Therefore, a new synthesis platform (Figure 4.11) which also enables conversion of highly viscous polyols and fatty acids from renewable resources to ester-based surfactants was designed. It is used by Evonik on a pilot scale, outperforming conventional methods, such as stirred-tank or fixed-bed reactors. In contrast to the setups introduced before, conversion of >99.6% is already obtained after 5.5 h in the bubble column reactor [44-47]. 

Completely negative results on the formation of liver glycogen were obtained when the sodium salts of caproic or caprylic acid61 60 were fed, as well as after the administration of the ethyl esters of caproic, caprylic, capric, myristic or oleic acids or methyl laurate.81 Caproic acid was found to be ineffective as a D-glucose-former in the phlorizinized dog.89... 

Figure 11.2 Py/silylation GC/MS chromatograms of aged linseed oil pyrolysed in the pre sence of HMDS, (a) Pyrogram obtained with a microfurnace pyrolyser pyrolysis temperature 600 °C furnace pressure 14 psi purge flow 0.5 ml min (b) Pyrogram obtained with a resistively heated filament pyrolyser pyrolyser interface I80°C transfer line 300°C valve oven 290°C. 1, Hexenoic acid, trimethylsilyl ester 2, hexanoic acid, trimethylsilyl ester 3, heptenoic acid, trimethylsilyl ester 4, heptanoic acid, trimethylsilyl ester 5, octenoic acid, trimethylsilyl ester 6, octanoic acid, trimethylsilyl ester 7, nonenoic acid, trimethylsilyl ester 8, nonanoic acid, trimethylsilyl ester 9, decanoic acid, trimethylsilyl ester 10, lauric acid, trimethylsilyl ester 11, suberic acid, trimethylsilyl diester 12, azelaic acid, trimethylsilyl diester 13, myristic acid, trimethylsilyl ester 14, sebacic acid, trimethylsilyl diester 15, palmitic acid, trimethylsilyl ester 16, stearic acid, trimethylsilyl ester...

TLC spots with marker reveal the presence of free fatty acids (FFA), diglyceride (DG), monoglyceride (MG) but negligible amount of TG. GCMS of fatty acid— methyl esters (FAME) from lion mane presented evidence for fatty acids ranging from C9-C24 (Figs. 5.3- 5.6). Low volatility molecules like nonanedioic acid (Fig. 5.3), tridecanoic acid (Fig. 5.4), 12-methyl tridecanoic acid were also present in lion hair lipids. In addition fatty acids such as myristic, pentadecanoic, palmitic, heptanoic, stearic and octadecenoic acids (Fig. 5.5) have also been detected. Erucic... 

Of the early references to the preparation of methyl myristate and methyl palmitate, few are of preparative value. Methyl myristate can be prepared by the fractional distillation of the methyl esters from ucuhuba fat4 and from cocoanut oil.5-6 Methyl palmitate can be prepared in a similar manner from cocoanut oil6 and from bayberry wax.7... 

This procedure has been used successfully for many years in the preparation of ethyl laurate, caprylate, and myristate by the alcoholysis of cocoanut oil (1 kg.) in ethanol (1900 g.) with hydrogen chloride (50 g.) as a catalyst.3 The method differs slightly from the one described above. The alcoholysis is complete after fifteen or twenty hours, and the solution is then neutralized to methyl orange with barium carbonate. The mixture is added to an equal volume of a saturated sodium chloride solution, whereupon 1100-1300 g. of the mixture of crude ethyl esters separates. This mixture of esters is washed with water and fractionated as described above. The yields are approximately 50 g. of ethyl caprylate, 350 g. of ethyl laurate, and 60 g. of ethyl myristate from 1000 g. of cocoanut oil. 

Myristic and palmitic acids can be obtained from their esters by the procedure in Org. Syn. Coll. Vol. 1, 371. From roo g. of methyl myristate is obtained 85-89 g. (90-95 per cent of the theoretical amount) of colorless myristic acid melting at 52-53°. From 100 g. of methyl palmitate is obtained 84-88 g. (90-95 per cent of the theoretical amount) of colorless palmitic acid melting at 62-63°. 

NK cells express receptors for numerous monokines constitutively, and produce IFN-y and other NK-derived cytokines rapidly in response to stimulation by monokines [18, 19]. Freshly isolated CD56 "s human NK cells are the primary source of NK cell-derived immuno-regulatory cytokines, including IFN-y, TNF-(3 (lymphotoxin), IL-10, IL-13 and GM-CSF, whereas the CDSb NK-cell subset produces consistently negligible amounts of these cytokines following stimulation with recombinant monokines in vitro [20]. The production of cytokines by NK cell subsets was investigated following activation with phorbol esters (e.g. phorbol 12-myristate 13-acetate (PMA)) and ionomycin. 

Phorbol esters are described as being protein kinase C activators and should be selective inhibitors for caveolae uptake [1 pM Phorbol 12-myristate 13-acetate (PMA) for 30 minutes] (48,68). The inhibition occurs as quickly as five minutes after adding PMA to cell culture medium and is not reversible within five hours (MA104 cells). However, PMA has several other effects on several other pathways. An example of this is that it has been described to stimulate macropinocytosis and transcytosis (see the following). 

Usually, the PFR serves as a probe reaction for the study of the morphology of the matrix. This has been demonstrated by Weiss and co-workers in a series of recent articles on the photoreactivity of esters included in several polyethylene films. Low-density polyethylene (LDPE) films hosting 2-naphthyl esters bring about different selectivity in the PFR as compared with the reaction in solution. In addition, the selectivity is different if the polymer is stretched [286,287], Table 16 indicates the different product distributions upon irradiation of 2-naphthyl esters, depending on the nature of the solvent or matrix. The most striking fact is that irradiation of 2-naphthyl myristate leads to the coupling at the position 1 in ferr-butanol with 86% yield, whereas this product is absent in the irradiations in polyethylene films. Moreover, the product of coupling at position 3 is absent... 

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