• Fibers and Polymers
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• v.3 no.2
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• pp.55-59
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• 2002

The thermal reaction of acetoacetanilide in the presence of aniline or phenol yielded carbanilide in quantitative yields. This reaction was applied to the synthesis of polyurea. Bisacetoacetamides were prepared from diamines and diketene in DMF. They were thermally polymerized in the presence of phenol or a diamine (6FDA) to yield polyureas of low molecular weights. The polymers were soluble in DMSO and NMP. $^1{H-NMR}$ analysis showed that they had amino group terminated structures. Poly(urea-imide) was synthesized by the reaction of an oligourea diamine with pyromellitic dianhydride in NMP. The concentration of terminal amino groups was determined by an acid-base titration. The thermal property of poly(urea-imide) was evaluated by thermogravimetric analysis (TGA). Initial decompisition took place at 332-$350^{\circ}C$.

• Korean Journal of Agricultural Science
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• v.41 no.4
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• pp.433-440
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• 2014

This study was conducted to investigate the effect of age on the contents of carnitine, free amino acid, and nucleotide-related compound in Holstein calf meat. Twenty calves were allocated into four age groups (3, 6, 9, or 12 mon of age; n=5/group), and ribeye (M. longissimus dorsi) and top round (M. semimembranosus) were excised from left side of each carcass on day 1 post-mortem. Carnitine contents for ribeye and top round were 0.79~1.16 and 0.65~1.26 mg/100 g, respectively, and those showed a tendency to be the highest in 3 mon group. The contents of majority of free amino acids were the highest (p<0.05) in ribeye and top round from 12 mon group. The contents of adenosine monophosphate, inosine monophosphate, and inosine were the highest (p<0.05) in ribeye and top round from 12 mon group, but hypoxanthine content was the lowest (p<0.05) in those from 12 mon group. These findings suggest that age decreases the carnitine content but increases free amino acid and good taste-related nucleotides contents in Holstein calf meat.

• Journal of the Korean Society of Food Culture
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• v.31 no.6
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• pp.643-651
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• 2016

This study was investigated the difference in the quality characteristics of the fermented soybean roasted with different conditions for making chungyukjang. Roasted condition of soybean was decided by pre-test, which was on $140^{\circ}C$ for 21 min, $180^{\circ}C$ 9.5 min, and $220^{\circ}C$ 6 min. Fermented soybean with different roasted condition and conventionally made cheonggukjang were measured for proximate composition, color, pH, amino nitrogen, ammonia nitrogen, free sugar and amino acids. The lightness and yellowness of soybean fermented by conventional method was higher than those of the fermented soybean with roasted soybean. The contents of free sugar of fermented soybean roasted on $220^{\circ}C$ for 6 min (FS220) was the highest among the group and followed by fermented soybean roasted on $180^{\circ}C$ for 9.5 min (FS180), $140^{\circ}C$ 21 min (FS140) and conventional cheonggukjang (FS0). The contents of total free amino acid was highest on fermented soybean roasted on $140^{\circ}C$ for 21 min (FS140) and followed by fermented soybean roasted on $180^{\circ}C$ for 9.5 min (FS180), $220^{\circ}C$ 6 min (FS220) and conventional cheonggukjang (FS0).

• Journal of Nutrition and Health
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• v.28 no.9
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• pp.846-854
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• 1995

Taurine concentrations in blood and various tissues were measured in cats fed normal trurine diet(0.15% taurine) and trurine-free diet(0% taurine) for 5 weeks and 12 weeks, respectively. Cumulative body weight gain in young cats fed normal taurine diet and taurine-free diet for the initial 5 weeks were 463$\pm$43g and 383$\pm$53g respectively. Taurine concentration was one to two orders magnitude higher in most tissues than in plasma, among which the liver taurine-free diet for 12 weeks resulted in 98% reduction in plasma taurine concentration, 93% reduction in whole blood tarurine concentration, and 40~90% reduction in tissue taurine concentrations compared to the values for normal taurine diet group. Among the tissues tested, taurine depletion was most profound in heart and kidney, while liver and intestine were relatively resistant to taurine depletion. Whole blood taruined concentration appeared to be a better index for the body taurine status of cats as in more closely reflects the rate of taurine depletion in tissues. Taurine depletion in cats significantly increased the concentrations of essential and non-essential free amino acids in liver, while free amino acid concentrations in other tissues were not affected by taurine depletion.

• Journal of the Korean Chemical Society
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• v.5 no.1
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• pp.33-37
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• 1961

We have shown that carboxy-peptidase destroys the biological activity of angiotensin octa-and deca-peptides. Since Proline occurs as the seventh amino acid from the amino end of the chain and since carboxypeptidase does not cleave proline from a peptid chain, it is evident that the heptapeptid H.asp-arg-val-tyr-ileu-his-pro.OH is formed by this hydrolysis. This peptide must then be biologically inactive. In order to determine whether the phenyl group of the C-terminal amino acid was the necessary requirement for biological activity of the octapeptide, $ala^8$ angiotensin octapeptide(amino acids of peptides numbered from amino end) was synthesized. For this synthesis the four dipeptides were prepared: carbobenzoxy-L-prolyl-L-alanine-P-nitrobenzyl-ester, m.p. $134-135^{\circ}C,$ carbobenzoxy-L-isoleucyl-imidazole benzyl-L-histidine methyl ester, m.p. $114-116^{\circ}C,$ carbobenzoxy-L-valyl-L-tyrosine hydrazide and carbobenzoxy B-benzyl-L-aspartyl-nitro-L-arginine. The first three dipeptides were obtained as crystalline compounds. Imidazole-benzyl-L-histidine was used in the hope that it would block the histidine imidazole against side reactions in steps subsequent to the formation of the C-terminal tetrapeptide. Also, it was through that the imidazole benzylated peptides would be easier to crystallize. This, however, was not the case. The tetrapeptide, carbobenzoxy-L-isoleucyl-L-im, benzyl-histidyl, L-prolyl-L-alanine-nitrobenzyl ester was not obtained in a crystalline form. Neither could the mono-or dihydrobromide of the tetrapeptide free base be induced to crystallize. Carbobenzoxy-L-valyl-L-tyrosine azide was condensed with the tetrapeptide free base to yield the protected hexapeptide; carbobenzoxy-L-valyl-L-tyrosyl-L-isoleucyl-L-im, benzyl, histidyl-L-Prolyl-L-alanine-nitrobenzyl ester. Upon removal of the carbobenzoxy group with hydrogen bromide in acetic acid an amorphous free base hexapeptide ester was obtained. This compound gave the correct C, H, N analysis and contained the six amino acids in the correct ratio. The octapeptide was obtained by condensing this hexapeptide with carbobenzoxy-B-benzyl-L-aspartyl-nitro, L-arginine using the mixed anhydride method of condensation. This amorphous product was proven to be homogenous by chromatography in two solvent systems and upon hydrolysis yielded the eight amino acids in correct ratio. The five protecting groups were removed from the octapeptide by hydrogenolysis over palladium black catalyst. Biological assay of the free peptide indicated that it possessed less than 0.1 per cent of both pressor and oxytocic activity of the phenylalanine8 angiotensin. This suggests that the phenyl group is a point of attachment between angiotensin and its biological receptor site.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.2
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• pp.155-161
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• 1998

This study conducted to evaluate effects of popped soybean on levels of ruminal peptides and blood amino acids in Holstein calves fed sudan grass hay as a forage source and popped (PSB) soybean as a concentrate supplement. At 0, 2, 4 and 6 h after feeding, rumen fluid and blood samples were collected from the rumen and jugular vein, respectively, and amino acids, peptides and other nitrogen-containing compounds in the rumen were analyzed. Ruminal pH tended to be higher in the RSB than in the PSB treatments, and declined upto 4 h after feeding, since then increased in both treatments. The concentrations of ammonia-N in all treatments increased upto 2 h after feeding, and then decreased gradually with time after feeding. The concentrations of ammonia N in the rumen were not significantly different between the treatments, however, those in RSB treatment appeared to be higher. Also, protein concentrations in the rumen were not significantly different between the treatments. Peptide productions were the highest at 2 h after feeding in the group fed RSB which is rapidly degradable in rumen, whereas those in the group fed PSB which is slowly degradable in rumen were maximized at 4 h after feeding. The concentration of total free essential amino acids in plasma was higher in the RSB treatment than in the PSB, but disappearance rates of these amino acids out of plasma was higher in the PSB treatment than in the RSB treatment. Disappearance rates of free non-essential amino acids in plasma were not significantly different between the treatments. Consequently, this study implies that the production of peptide and utilization of blood amino acid may be controlled by the modification of protein degradability.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.2
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• pp.239-249
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• 1999

The role of amino acids in culture media for IVF-ET was examined in a total of 76 cycles. Patients received clomiphene citrate (CC) followed by hMG or GnRH-a combined with gonadotropins (FSH/hMG) for controlled ovarian hyperstimulation. Severe male (<$4{\times}10^6$ motile sperm) or age factor (>39 y) patients were excluded in this study. Pregnancy was classified as clinical if a gestational sac or fetal cardiac activity was seen on ultrasound. No significant differences were found in age, duration of infertility, follicle size, the level of $E_2$ on the day of hCG injection, the mean number of oocytes retrieved, total motile sperm count, fertilization rate and the mean number of embryos transferred between bHTF (without amino acids) and mHTF (with amino acids) groups. However, total ampules of gonadotropins were higher (p<0.01) in mHTF group than bHTF group. Significantly (p<0.05) more clinical pregnancies were recorded in mHTF group (13/30) compared with bHTF group (9/46). The multiple pregnancy rates were 11.1% in bHTF group and 7.7% in mHTF group. There were one ectopic pregnancy in mHTF group and one heterotopic pregnancy in bHTF group. Abortion rates were 22.2% in bHTF group and 7.7% in mHTF, respectively. The ongoing pregnancy or livebirth rate was significantly (p<0.05) higher in mHTF group (12/30) than bHTF group (7/46). These results suggest that the addition of amino acids in culture media is essential for culture of zygotes in vitro and adjustment of energy substrates in phosphate-free culture media appears to be beneficial for human IVF-ET procedure.

• Applied Biological Chemistry
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• v.30 no.3
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• pp.210-218
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• 1987

In the previous report, we isolated and purified one of tendering enzyme 'ficin' from fig latex. In this study, various crude ficin concentrations and reaction time were employed to investigate the contents of free amino acids and other free nitrogen compounds after the treated with beef round muscle. 1. Free amino acids contents increased with the increase of temperature and time during the aging of beef at $1^{\circ}C$ and $8^{\circ}C$, and the increasing rate was remarkably high when fresh beef was treated with ficin. In the case of ficin treatment after various cooking, steaming showed the highest increase in free amino acid contents among three cooking methods such as boiling, steaming and pan broiling. The increased amounts of free amino acids in three groups-aging beef at $1^{\circ}C$ for 3 days, fresh beef treated with ficin(0.1%, 2hrs) and beef treated with ficin(0.1%, 2hrs) after cooking were 13%, 293% and 137% respectively. In contrast to aging group, the amount of free amino acids in other two groups treated with ficin was superiorly increased. 2. The amounts of total free nitrogen, free non-protein nitrogen and $NH_3-nitrogen$ increased with the increase of temperature and time during the aging of beef at $1^{\circ}C$ and $8^{\circ}C$, and the increasing rate was remarkably high in fresh beef treated with ficin. In the case of ficin treatment after cooking, steaming gave larger amount of total and non-protein nitrogen than other two cooking, e.g. boiling and panbroiling. The increasing rate of nonprotein nitrogen to the total nitrogen of fresh beef treated with ficin(0.1%, 2hrs) was 75 times greater than that of aging fresh beef at $1^{\circ}C$ for 3 days.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.6
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• pp.570-578
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• 2012

The present study investigated the effect of diets supplemented with different levels (0, 1, 3, and 5 %) of fig leaf ethanol extract (FLEE) on the nutritional composition of black rockfish Sebastes schlegeli. Fish ($10.05{\pm}0.44g$) were fed to apparent satiation twice daily for 8 weeks. Adding FLEE decreased crude lipid levels and increased crude protein and ash. Among the three organic acids in the whole body of black rockfish, lactic acid was predominant, followed by citric acid and oxalic acid. Five free sugars were found in all groups. Fucose and glucose were the dominant free sugars in the FLEE-added group. The abundant fatty acids in the FLEE-added group were C16:0, C18:1-cis (n9), and C22:6n-3. The major amino acids in the samples were glutamic acid, aspartic acid, glycine, leucine, alanine, lysine, and arginine. The abundant free amino acids in the FLEE-added group were taurine, glutamic acid, alanine, leucine, and arginine.

• Food Science of Animal Resources
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• v.20 no.1
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• pp.8-14
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• 2000

In order to examine physicochemical gelation behavior of ultra high temperature(UHT) pasteurized milk during storage at 4$^{\circ}C$ and 25$^{\circ}C$, pH, electrophoresis, alcohol test, sialic acid contents and free amino groups contents were biweekly determined. The pH of UHT pasteurized milk decreased with increasing storage time. Gelation of the UHT milk occured faster at 25$^{\circ}C$ than at 4$^{\circ}C$ with larger decreasing rate of pH. The alcohol test showed positive results at lower pH than 6.5, which could indicate the casein instability and beginning of gelation. The electrophoretic patterns showed a decrease in the concentrations of all caseins. Degradation of k-casein was faster in all cases, while $\alpha$-casein and $\beta$-casein were also extensively degraded later. The sialic acid contents of the samples increased gradually during storage, and the increasing rate was higher before gel formation. The free amino groups of the samples increased gradually during storage. The increasing rate of free amino groups was faster at 25$^{\circ}C$ than at 4$^{\circ}C$. The samples stored at 25$^{\circ}C$ gelled earlier than those stored at 25$^{\circ}C$, with corresponding increase of free amino groups. The residual proteolytic enzymes, which survived during the UHT heat treatments and were reactivated during storage, could be responsible for UHT pasteurized milk gelation during storage. It is assumed that proteolytic degradation of caseins followed by aggregation would be attributable to complicated reaction mechanism.