Acetone treatment

After the removai of acid, the nitrate was dried by suction on the nutsch for about 15 minutes. The dried material was refined by means of acetone treatment or other suitabie refining means. About 210 parts refined pentaerythritol tetranitrate per charge was obtained. 

Figure 8.18 Acetone treatment of Geotrichum candidum for the improvement of enantioselectivity [14].

Mohammed ( ) reported that acetone treatment of aqueous cotton dust extract caused the precipitation of several sugars and an aminopolysaccharide. The sugars were present in concentrations equal to those which exhibited contractile activity on guinea pig... 

Treatment with formaldehyde or acetone Treatment with phenol or phenol and heat Treatment with propiolactone... 

All ALP products absorbed more oil than the soy products. Acetone treatment of ALP resulted in reduced fat absorption ALP with higher lipid contents absorbed more oil. ALP extracted with water and NaOH absorbed more oil than those extracted with NaCl or Tris buffer. These researchers (19) attribute fat absorption to physical entrapment a correlation of 0.95 was found between fat absorption and bulk density. However, more oil was absorbed by the ALP than the soy products even though the products had similar bulk densities. 

These observations are consistent with those reported by Deckert and Peters [9], where greater lifting or poorer adhesion was reported to occur for sulfuric acid/ peroxide reworked wafers. Obviously, reworking wafers is not desirable however, when economically necessary, simple solvent treatments on a wafer track like the acetone treatment are attractive and can be effective. Actually, other organics work as well as acetone cellosolve acetate and other cellosolves also work well. 

D-Glucose was reduced to the D-sorbitol with a hydrogen over Ni Raney, then it was turned into the L-sorbose with the acetobacter suboxydans and the hydroxyl groups of L-sorbose were protected with acetone treatment yielded the diaceton-L-sorbose. Subsequent treatment with NaOCI/Raney Ni produced di-O-isopropylidene-2-oxo-L-gulonic acid. Partial hydrolysis with aqueous HCI gave deprotected 2-oxo-L-gulonic acid, which yielded ascorbinic acid by heating with HCI. 

Acetone treatment is also used for barrier disruption.14 Compared to tape stripping, this treatment breaks the SC barrier homogeneously. On the other hand, it takes a longer period of time to break... 

Treatment with the surfactant is another way to break the barrier, as described earlier.10 The efficacy depends on each surfactant. Yang et al.15 suggested that some kinds of anionic surfactant, such as sodium dodecyl sulfate (SDS), affect not only the SC barrier, but also the nucleous layer of the epidermis. Fartasch demonstrated16 that the topical application of SDS caused cell damage to the nucleated cells of the epidermis and acetone treatment disrupted the lipid structure only in the SC. Thus, if one wants to investigate the effect of the disruption of the SC barrier function, tape stripping or acetone treatment would be better for the study. 

Feingold and his coworkers demonstrated an important role of nuclear hormone receptor on epidermal differentiation and stratum corneum barrier formation. Activation ofPPARa Peroxisome proliferator-activated receptor a by farnesol also stimulated the differentiation of epidermal keratinocytes.42 Cornified envelope formation, involcrin, and transglutaminase protein, and mRNA levels were also increased by the activation of PPARo . Interestingly, the inflammatory response was also inhibited by the treatment.43 They also showed that topical application of PPARo activators accelerated the barrier recovery after tape stripping or acetone treatment and prevented the epidermal hyperplasia induced by repeated barrier disruption.42 Regulation of the nuclear hormone receptor would open a new possibility for improvement of the cutaneous barrier. 

Denda, M., Wood, L.C., Emami, S., Calhoun, C., Brown, B.E., Elias, P.M., and Feingold, K.R. (1996) The epidermal hyperplasia associated with repeated barrier disruption by acetone treatment or tape stripping cannot be attributed to increased water loss. Arch. Dermatol. Res. 288 230-238. 

The role of mast cells and histamine inducing itch remains unclear in dry skin. It has been shown that histamine concentrations increase 48 hours following acetone treatment in a dry environment.23 A subsequent study demonstrated an increased number of mast cells and histamine levels in the dermis of hairless mice in response to low environmental humidity.46 The authors did not examine a relationship between scratching behavior with the increase in mast cells and histamine. Miyamoto et al. used the mouse model treated with water followed by 1 1 acetone ether to see if they could demonstrate an increase in mast cell number or degranulation however, they found no difference.24 Furthermore, they performed the same study on mast cell deficient mice and were able to induce a similar scratching behavior, which suggests that mast cells may not play a definite role in the mechanism of itch in dry skin. 

Thus far, all examples related to the addition of nucleophiles to carbonyls involve basic (anionic) conditions. However, such conditions are not required. Recalling that a carbonyl oxygen atom possesses a partial negative charge, we recognize that under acidic conditions it can be protonated. The protonation of carbonyl groups, illustrated in Scheme 7.13, was discussed in Chapter 3. Thus, as shown in Scheme 7.14 using acetone, treatment of... 

The enzyme activity was assayed in cell-free preparations with NAD(P) as the hydrogen acceptor. X-Press and acetone treatment proved to be the best methods for cell desintegration. During centrifugation the greater part of the enzyme activity sedimented with the cell wall cytoplasmic membrane fraction. 

The highest specific activity of dehydrocyclopeptine epoxidase was measured after acetone treatment of hyphal cells and conidiospores. More than one-third of the measurable activity sedimented with the cell wall-plasma membrane fraction, from which it could be solubilized by a 1% solution of deoxycholate. The soluble enzyme fraction was purified by ammonium sulfate precipitation and gel chromatography, and its molecular weight was estimated to be near 500,000. 

Animal tissues (Multi-residue method) homogenize extract with n-hexane-acetone treatment with sulfuric acid gel permeation chromatography chromatography or silica gel chromatography or activated charcoal GC/MS (NCI) 10 ng/kg [37]... 

Further enrichment to a Chl/P700 ratio of 16 was achieved by Sane and Park by acetone treatment of PS-I particles obtained from the French press. A photosystem-I particle with a dramatically reduced chlorophyll content was obtained by Ikegami and Katoh , who treated lyophilized PS-I particles first prepared by digitonin treatment with diethyl ether partially saturated with water to -50-80% ( wet ether). The Chi/ P700 ratio in such particles was as low as 10 and all chemically oxidizable P700 present in the particle... 

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