Reference

Solubilization of cattle and pig hair keratins by reduction with sodium thioglycolate or oxidation with performic acid

Solubilization of cattle and pig hair keratins by reduction with sodium thioglycolate or oxidation with performic acid. Uehara, Kohkichi; Matsunaga, Ayako; Arai, Katsuhiko; Toyoda, Harukazu; Chonan, Yasumasa (Scleroprotein Leather Res. Inst., Tokyo Noko Univ., Fuchu 183, Japan). J. Am. Leather Chem. Assoc., 81(10), 331-7 (English) 1986. CODEN: JALCAQ. ISSN: 0002-9726. DOCUMENT TYPE: Journal CA Section: 45 (Industrial Organic Chemicals, Leather, Fats, and Waxes) The soly. of cattle and pig hair keratins decreased as the concn. of Na thioglycolate (I) [367-51-1] increased, and the soly. was the highest at 0.1 M concn. The keratins were little dissolved in 0.1M I soln. below pH 10. Although the quantity of solubilized keratins was increased by incubating at higher pH, at higher temp., and for longer times, the possibility of peptide bond cleavage was also increased. The soly. of steer and pig hair keratins which were treated with 0.1M I at pH 11 and 35° was approx. 60 and 50%, resp. The soly. of keratins oxidized with performic acid (II) [107-32-4] varied with the concn. of oxidized acid and incubation time. After 6 h incubation, the soly. of steer and pig hair keratins varied from 50 to 85% and from 50 to 70%, resp., depending on oxidative conditions. However, by using alkali treatment after oxidative decompn., the total solubilities in both I and II solns. were similar to each other, i.e, the differences in the total solubilities between steer and pig hair keratins and between 6 and 24 h incubation decreased. The soly. of steer and pig hair keratins treated with 90% HCO2H-3% H2O2 at 25° was approx. 75% and 50% after 6 h incubation, and approx. 90% and 80% after 24 h incubation, resp. The total solubilities using the alkali treatment of steer and pig hair keratins were approx. 90 and 85% after 6 h incubation, and approx. 95 and 90% after 24 h incubation, resp.

Natural inhibitors of selenium-dependent glutathione peroxidase

Natural inhibitors of selenium-dependent glutathione peroxidase.Some chemicals with cas registry numbers like 70-49-5 and 9013-66-5 are also used. Combs, G. F., Jr.; Mercurio, S. D. (Dep. Poult. Avian Sci., Cornell Univ., Ithaca, NY, USA). Proc. - Cornell Nutr. Conf. Feed Manuf., 39-43 (English) 1986. CODEN: PNCFAB. DOCUMENT TYPE: Journal CA Section: 17 (Food and Feed Chemistry) Section cross-reference(s): 4, 7 Several mercaptans (which are found in many foods as natural constituents or contaminants) inhibited Se-dependent glutathione peroxidase (I) [9013-66-5] of bovine and chick liver and bovine erythrocyte in vitro. The order of inhibiting potency was mercaptosuccinate (II) [70-49-5] = N-2-mercaptopropionylglycine (III) [1953-02-2] ? penicillamine (IV) [52-67-5] = b-mercaptopyruvate (V) [2464-23-5] = thioglycolic acid [68-11-1] > S-methylglutathione (VI) [2922-56-7] ? 3-methylthiopropionylaldehyde [3268-49-3] ? L-cysteine [52-90-4]. Exudative diathesis (ED), a sign of Se deficiency, was obsd. in Se-adequate, vitamin E-deficient chicks in response to administration of IV, V, or VI. The compds. which increased ED incidence showed inverse correlation between dose and liver I activity. Those compds. that inhibited I in vitro also reduced I activity in vivo and increased the incidence of ED in Se-adequate, vitamin E-deficient chicks. The 3 mercaptans that were most inhibitory to I were II, III, and Na thioglycolate [367-51-1]. The possible neg. effect of mercaptans on the availability of Se is emphasized. .