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Lipid peroxidation and its measurement
Published in Roger L. McMullen, Antioxidants and the Skin, 2018
As already stated, peroxides are usually the first intermediate products of lipid peroxidation, followed by further decomposition to aldehydes and ketones. The p-anisidine value (AV) test measures the amount of aldehydes, predominantly 2-alkenals and 2,4-dienals, that react with the probe, p-anisidine. This assay, developed almost 40 years ago, is still in common use today.138,139 It is a modification of an earlier developed test to determine benzidine value, in which case benzidine was replaced by p-anisidine due to its carcinogenecity.140,141 It should be noted, however, that the toxicological profile of p-anisidine is such that it should not be allowed to come in contact with skin.141,142 The test for AV measures the amount of secondary lipid oxidation products present in the sample due to the reactivity of p-anisidine with compounds containing carbonyl groups. Figure 5.12 illustrates possible reaction routes that may be followed by p-anisidine and several forms of aldehydes.
Cannabis Oil
Published in Amritpal Singh Saroya, Reverse Pharmacology, 2018
Microwave treatment resulted in improvement of the yield of oil. It increased the amount of carotenoid and other pigments. The treatment, however, decreased p-anisidine value. As far as tocopherols are concerned, p-tocopherol concentrations was found to be increased. y-tocopherol, and fatty acid composition of the oil was found to be unaffected by microwave treatment of hempseed.
Nasal Cavity Carcinogens: Possible Routes of Metabolic Activation
Published in D. V. M. Gerd Reznik, Sherman F. Stinson, Nasal Tumors in Animals and Man, 2017
Stephen S. Hecht, Andre Castonguay, Dietrich Hoffmann
Several aromatic amines with methyl or methoxy groups ortho to the amine functionality are more carcinogenic than the corresponding unsubstituted compounds or than those with meta and para substitutents. For example, o-toluidine is more carcinogenic than aniline, and o-anisidine is a fairly potent bladder carcinogen in rats.85,86 In contrast, p-anisidine and p-toluidine are only weakly carcinogenic or inactive.85,87 Since p-cresidine has a methoxy group ortho to the amino group, its mechanism of activation may in some way be similar to those of o-toluidine and o-anisidine. However, no metabolic studies have been reported on p-cresidine.
N-terminal selective conjugation method widens the therapeutic window of antibody–drug conjugates by improving tolerability and stability
Published in mAbs, 2021
Min Ji Ko, Daehae Song, Juhee Kim, Jae Yong Kim, Jaehyun Eom, Byungje Sung, Yong-Gyu Son, Young Min Kim, Sang Hoon Lee, Weon-Kyoo You, Jinwon Jung
Several studies using N-terminal modification of a protein have been reported. Thompson et al. demonstrated selective labeling of alkoxyamine-derivatized MMAE to a serine residue engineered at the N-terminal of light chain.20 The method oxidizes the serine to an aldehyde group by sodium periodate and the linker-payload conjugated by oxime ligation reaction. They only demonstrated that they could make the ADC, and the ADC was stable in serum and showed in vivo potency. Because the N-terminal aldehyde is the only active site, the resulting ADC is homogeneous. This method seems to be limited by two points: the need for protein engineering and use of toxic p-anisidine. In comparison with the N-terminal modification method, an advantage of our approach is that there is no need for antibody engineering. Addition of serine at the N-terminus of an antibody is quite easy, but sometimes it is not possible. For example, ADCs can be made from an antibody that is already manufactured using an established process and cell bank, but that antibody cannot be further engineered unless the manufacturing process is also changed, which can be costly and time-consuming.
The Effect of Phytosterol-Rich Fraction from Palm Fatty Acid Distillate on Blood Serum Lipid Profile of Dyslipidemia Rats
Published in Journal of Dietary Supplements, 2018
Kgs Ahmadi, Huda Oktafa, Teti Estiasih
Data in Table 1 show that PFAD had high free fatty acids of 87.83%; PRF had free fatty acids of 14.40%. Free fatty acids of PRF were an impurity that ideally should be eliminated during low-temperature solvent crystallization in PRF preparation. Both PFAD and PRF revealed low oxidation levels, indicated by peroxide value as an indicator of primary oxidation and anisidine value as an indicator of secondary oxidation. The p-anisidine value of PRF was higher than that of PFAD, possibly due to accumulation of low molecular secondary oxidation products in PRF. The peroxide value of PFAD was higher than that of PRF because peroxides are primary oxidation products that usually have high molecular weight and dissolve in solvent during low-temperature solvent crystallization; thus, they did not accumulate well in PRF.
Microencapsulation of esterified krill oil, using complex coacervation
Published in Journal of Microencapsulation, 2018
Selim Kermasha, Sarya Aziz, Jagpreet Gill, Ronald Neufeld
Determination of p-AnV: To monitor the secondary oxidation products of the investigated EOs and their esterified PLs, p-AnV was determined according to the AOCS Official Method Cd 18–90 (AOCS, 2009). The p-AnV was calculated as: p-anisidine reagent and Ab = absorbance of the fat solution.