Effect of Acetylation

Derivatization of lignin often discloses hidden features of IR spectra. A difference spectrum of acetylated lauan (Shorea polysperma) MWL, shown in Fig. 4.1.14, demonstrates the effects of acetylation. The OH band at 3410-3460cm-1 disappears upon acetylation acetoxy bands appear at 1765-1772cm-1 (shoulder, aromatic), 1743cm-1 (aliphatic), 1371cm-1, as do peaks in a cluster with maxima at 1217, 1225-1227, and 1198cm-1. It is noteworthy 

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Herzberg U, Sagen J (2001) Peripheral nerve exposure to HIV viral envelope protein gpl20 induces neuropathic pain and spinal gliosis. J Neuroimmunol 116(l) 29-39 Herzmann C, Johnson MA et al (2005) Long-term effect of acetyl-L-carnitine for antiretroviral toxic neuropathy. HIV Clin Trials 6(6) 344-350... 

Woosley, R.L. et al., Effect of acetylator phenotype on the rate at which procainamide induces antinuclear antibodies and the lupus syndrome, New Engl. J. Med., 298, 1157, 1978. 

Mahlberg etal. (2001) studied the effect of acetylation of wood fibres (20 % WPG) upon the mechanical properties of wood fibre PP fibre composites, with and without the addition of a novalak PF. Acetylation resulted in significant improvements in MOR, MOE and IBS in a composite containing 20 % by weight of PP fibre. With a combination of PF and PP (both 10 % by weight) and acetylated wood fibre, MOR was unchanged, MOE decreased and only IBS showed a significant improvement. Acetylation also contributed to a better dispersion of the wood fibres in the PP matrix. 

Arora, M., Rajawat, M.S. and Gupta, R.C. (1981). Effect of acetylation on properties of particleboards prepared from acetylated and normal particles of wood. Holforschung und Holzyerwertung, 33( 1), 8-10. 

Chowdhury, M.J.A. and Humphrey, P.E. (1999). The effect of acetylation on the shear strength development kinetics of phenolic resin-to-wood bonds. Wood and Fiber Science, 31(3), 293-299. 

Kumar, S., Singh, S.P. and Sharma, M. (1979). Effect of acetylation on the permeabdity of wood. Journal of the Timber Development Association of India, 25(3), 5-9. 

Ramsden, M.J., Blake, F.S.R. and Fey, N.J. (1997). The effect of acetylation on the mechanical properties, hydrophobicity and dimensional stability of Pinus sylvestris. Wood Science and Technology, 31(2), 97-104. 

Sander, C. and Koch, G. (2001). Effects of acetylation and hydrothermal treatment on lignin as revealed by cellular UV-spectroscopy in Norway spruce (Picea abies [L.] Karst.) Holzforschung, 55(2), 193-198. 

Subiyanto, B., Yusuf, S., Kawai, S. and Imamura, Y. (1989). Particleboard from acetylated albizzia particles. 1. The effect of acetyl weight gain on mechanical properties and dimensional stability. Mokuzai Gakkaishi, 35(5), 412-418. 

Takahashi, M., Imamura, Y. and Tanahashi, M. (1989). Effect of acetylation on decay resistance of wood against brown rot, white rot and soft rot fungi. International Research Group on Wood Preservation, Doc. No. IRGAVP 3540. 

Figure 1. Mechanistic effect of acetylation/deacetylation of histones and nonhistones on chromatin stracture.(a) Acetylation of non-histone proteins results in transcriptional activation (b) Acetylation of ORCl by HBOl is important for replication, (c) Acetylation of newly synthesized...

The global effects of acetylation have long been recognized [153] and studied in the chromatin field [126,127,154—156]. However, whether such effects are the... 

Widlund, H.R., Vitolo, J.M., Thiriet, C., and Hayes, J.J. (2000) DNA sequence-dependent contributions of core histone tails to nucleosome stability Differential effects of acetylation and proteolytic tail removal. Biochemistry 39, 3835-3841. 

G Dongowski, B Schnorrenberger, M Platzer, M Schwarz, R Neubert. Interactions between food components and drugs. Part 5. Effect of acetylation and amidation of pectins on the interaction with drugs. Int J Pharm 158 99-107,... 

Stockwell, W. R., J. B. Milford, D. F. Gao, and Y. J. Yang, The Effect of Acetyl Peroxy-Peroxy Radical Reactions on Peroxy-acetyl Nitrate and Ozone Concentrations, Atmos. Enriron., 29, 1591-1599(1995). 

Figure 10.9 Effects of acetylation on the granule morphology of maize and potato starches, (a) Native maize starch granules, (b) Acetylated maize starch granules, (c) Native potato starch granules, (d) Acetylated potato starch granules (Singh et al., 2004a).

Gonzalez, Z., Perez, E. (2002). Effect of acetylation on some properties of rice starch. Starch, 54,148-154. 

Singh, J., Kaur, L., Singh, N. (2004b). Effect of Acetylation on Some Properties of Com and Potato Starches. Starch, 56, 586-601. 

The negative effects of acetyl-CoA on pyruvate dehydrogenase activity are supplemented by ATP and NADH. These effects are in the correct direction to cause the rate of acetyl-CoA synthesis to vary with the need for electrons and for regeneration of NADH and ATP. 

Table V. Effect of Acetylation on Hygroscopicity of Chir at Various Relative Humidities.

Effect on Strength Properties. The few studies conducted on the effect of acetylation on strength properties indicate that acetylation with acetic anhydride had no immediate adverse effect... 

Fig. 18. Effects of acetylation or succinylation of iron ovotransferrin on stabilities of complexes in urea. Acetylated was40% modified succinylated was60—70% modified. General conditions are described in text. Reactions were performed withh 0.5% protein in 0.005 m NaHCOs, 0.001 m sodium citrate, 0.001 m FeNH4(S04)2 at pH 8.4, and 0—8 m urea. Optical densities were determined at 470 mp A — A. unmodified (control) iron ovotransferrin in 0—8 m urea for 1 hour —, acetylated or succinylated ovotransferrin in 0—8 m urea immediately after mixing (zero time) O—O. acetylated or succinylated ovotransferrin in 0—8 m urea for 1 hour. (Biochemistry 4, 998 [1965]).

Groninger (38) succinylated fish myofibrillar protein and examined some of its chemical and functional properties. The fish myofibrillar proteins were succinylated at different levels and the degree of succinyla-tion was related to a functional property such as emulsification capacity. The protein efficiency ratio for succinylated protein was lower than that of untreated fish protein. Grant (39) succinylated wheat flour proteins and analyzed their solubility, viscosity, and chromatographic behavior. The effects of acetylation and succinylation on the physicochemical and functional properties of several plant proteins was reviewed recently by Kinsella and Shetty (6). 

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