• KSBB Journal
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• v.27 no.4
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• pp.232-236
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• 2012

Comparative liquid chromatographic enantiomer separation of ${\alpha}$-amino acids, their esters and primary amino compounds was performed using two chiral stationary phases (CSPs) prepared by covalently bonding (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid (18-C-6-TA) of the same chiral selector. In general, the separation factors and resolution factors for these analytes on CSP 1 were greater than on CSP 2, while these capacity factors on CSP 2 were quite greater than on CSP 1. Except for leucine methyl ester and phenylalanine methyl ester, the elution orders of all analytes including ${\alpha}$-amino ${\alpha}$-alkyl acids and phenylglycine alkyl esters on CSP 1 are identical to those on CSP 2. This study showed that different connecting structures for these two CSPs might influence their ability to resolve the analytes depending on their structures related to the chiral recognition mechanism.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.910-914
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• 2007

In order to synthesize new bioactive compounds and contrasting agents, reactions of glycine and glutamic acid as an animo acid with paraformaldehyde and hypophosphorous acid were executed. Products are 3,7-dihydroxy-3,7-dioxoperhydro-1,5,3,7-diazadiphosphocine-1,5-diacetic acid 1 and 3,7-dihydroxy-3,7- dioxoperhydre-1,5,3,7-diazadiphosphocine-1,5-di-(2-glu taric acid) 3. 2-[5-(1,2-Dicarboxyethyl)-3,7-dihydroxy-3,7-dioxo-315.715-[1,5,3,7] diazadiphosphocan-1-yl]-succinic acid 2 by using aspartic acid was not obtained. Esterification of 3,7- dihydroxy-3,7-dioxoperkydro-1,5,3,7-diaza-diphosphocine-1,5-diacetic acid 1 by treatment of methanol, ethanol, and propanol were executed. 3,7-Dihydroxy-3,7-dioxoperhydro-1,5,3,7-diazadiphosphocine-1,5-diacetic acid methyl ester 4, 3.7-dihydroxy-3,7-dioxoperhydro-1,5,3,f-diazadiphosphocine-1.5-diacetic acid ethyl ester 5, and 3,7-dihydroxy-3,7-dioxoperhydro-1,5,3,7-diazadiphosphocine-1,5-diacetic acid propyl ester 6 were respectively synthesized in good yields. Continuously, we will try synthesis of novel compounds and evaluation of biological activity.

• Macromolecular Research
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• v.8 no.5
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• pp.199-208
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• 2000

The recent development of biodegradable polymers for drug delivery system (DDS) has been investigated. The biodegradable polymers for DDS are mainly discussed in two categories: one category is natural biodegradable polymers such as polysaccharides, modified celluloses, poly(${\alpha}$-amino acid)s, modified proteins, and microbial biodegradable polymers; the other is synthetic biodegradable polymers such as poly(ester)s, poly(ortho ester)s, poly(phosphazene)s, poly(anhydride)s, poly(alkyl cyanoacrylate)s, and multiblock copolymers. The bioconjugate polymeric drug delivery systems have been also proposed for the design of biocompatible polymeric controlled drug delivery.

• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.54-61
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• 1998

Samjangs (Korean-style mixture of soybean paste) were prepared using magjang, traditional doenjang (Korean style soybean paste), and mixture of traditional doenjang and magjang (a kind of Korean style soybean paste) as a main composition. Charateristics including volatile compounds were investigated. Total sugar in samjang by using magjang was higher than that of other treatment while reducing sugar of the mixed treatment was high. Glutamic acid $(230.6{\sim}310.9\;mg/100\;g)$ was highest among free amino acids. Hunter color values of samjang with magjang was lower than those of others. Volatitle flavor components of smajang were identified with GC and GC-MSD. Fifty four components including 11 alcohols, 7 esters, 13 acids, 3 aldehydes, 4 alkanes, 4 phenols, 3 pyrazine and others were found in samjangs. Ethanol, acetic acid ethyl ester, 3-methyl butanoic acid, 2,4-hexadienoic acid and acetic acid might be major volatile components considering of high peak area. Pentanoic acid methyl ester and 4-methoxy-2-buten-1-ol were higher than other components in samjang with magjang while 2-methyl-1-propanol, butanoic acid and 3-methyl butanoic acid were in samjang with traditional doenjang and ethanol, acetic acid ethyl ester and 2,4-hexadienoic acid were in the mixed treatment.

• Archives of Pharmacal Research
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• v.21 no.6
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• pp.723-728
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• 1998

The chemical behaviours of 4-methyl-2-oxo-2H-benzopyran-7-yl oxoacetyl hydrazine (2) towards some different reagents such as anhydride compounds, aromatic aldehydes, carb on disulphide, and nitrous acid yielded the corresponding pathalazine derivatives (3, 4, 5), hydrazone derivative (6), 1,3,4-oxadiazole derivative (7, 8, 9) and acid azide (10) respectively. Treatmen of 10 with absolute alcohols, amines and ethyl amino acid ester gave the corresponding carbamate derivative (11), substituted urea derivative (12) and ethyl substituted alkyl acetate (13) respectively. The biological activity of some synthesized compounds was evaluated.

• Journal of the Korean Chemical Society
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• v.53 no.2
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• pp.137-143
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• 2009

Liquid chromatographic enantiomer separation of N-tert-butoxycarbonyl (BOC) $\alpha$-amino acids and their ethyl esters was performed on covalently immobilized chiral column (Chiralpak IC) derived from polysaccharide derivative. The solvent versatility of the covalently immobilized Chiralpak IC in enantiomer separation of N-BOC $\alpha$-amino acid ethyl ester derivatives was shown and the chromatographic parameters of their enantioselectivities and resolution factors were greatly influenced by the nature of the mobile phase. Also the effect on the dissolving solvent for these analytes on the enantiomer separation using the same mobile phase and the examples of preparative enantiomer separation on analytical column were shown.

• Archives of Pharmacal Research
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• v.12 no.1
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• pp.58-61
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• 1989

Studies of selectivity of hydrogen bond formation in chiral solute-solvent systems have been performed by $^1H\;and\;^{13}C$ nuclear magnetic resonance techniques. These data are correlated with the results of gas chromatographic investigations of the same systems. Interactions between the optically active solvent(N-(N-benzoyl-L-amino acid)-anilide) and optically active solute (N-trifluoroacetyl -L-alanyl isopropyl ester) were examined. NMR evidence indicated that hydrogen bonding interaction occurred between two N-H portion and on peptidyl carbonyl portion in stationary phase and solute molecule on three points. The association constants of solvent-solute interaction were calculated and the structure of the diastereomeric association complex between N-(N-benzoyl-L-valyl)-anilide and N-TFA-L-alanyl isopropyl ester was proposed.

• Archives of Pharmacal Research
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• v.23 no.6
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• pp.564-567
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• 2000

The use of amino acid derivatives as building blocks in peptide synthesis is increasingly being recognized as a potential route for the development of pharmaceutical agents. Side chain protection of polyfunctional amino acids such as Ser, Thr, Tyr is viewed as being particularly important. Although these derivatives are commercially listed, they are expensive and not widely available. We describe here a practical large-scale synthesis of t-butyl introduced D-serine, one of the building blocks of zoladex, a peptide drug.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.2
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• pp.267-276
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• 2005

This study was carried out to investigate the effect of phytosterol ester addition on lowering blood cholesterol in cholesterol-reduced Cheddar cheese. For cholesterol removal, separated cream was treated with 10% ${\beta}$-cyclodextrin at 800 rpm, then blended with remaining skim milk and homogenized with 1,000 psi at $70^{\circ}C$. Experimental cheeses were manufactured by five different levels of phytosterol addition. After the cholesterol reduction process by ;${\beta}$-cyclodextrin, the cholesterol removal rate was in the range of 91.0 to 92.1%. Amount of short-chain free fatty acid and free amino acids increased with an increase of phytosterol ester, and those were significantly different from that of control in all ripening periods. All rheological properties also increased with an increase of phytosterol ester during ripening period. In sensory analysis, the scores of rancid, bitterness Cheddar flavor and off-flavor intensities increased significantly, while texture was decreased during ripening in phytosterol ester-added groups. Total blood cholesterol was reduced by 18% when rats were fed Cheddar cheese treated with 8% phytosterol. The present study indicated that phytosterol ester addition resulted in a profound lowering effect of blood with cholesterol-reduced Cheddar cheese.

• Bulletin of the Korean Chemical Society
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• v.15 no.4
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• pp.324-326
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• 1994