• Journal of the Korean Applied Science and Technology
• /
• v.38 no.3
• /
• pp.824-831
• /
• 2021

1, 2-Octanediol galactoside (OD-gal) has been synthesized from 1, 2-octanediol (OD), as a safer cosmetic preservative, using recombinant Escherichia coli β-galactosidase (β-gal). To confirm the molecular structure of synthesized OD-gal, mass spectrometry and NMR (¹H- and ¹³C-) spectroscopy of OD-gal were carried out. In the reaction mixture, a sodium adduct ion of OD-gal (m/z=331.1732) was identified using mass spectrometry analysis. In addition, ¹H NMR spectrum of OD-gal showed multiple peaks corresponding to the galactosyl group, which is evidence of galactosylation on OD. Downfield proton peaks at δ_H 4.39 ppm and multiple peaks from δ_H 3.98~3.55 ppm were indicative of galactosylation on OD. Up field proton peaks at δ_H 1.52~1.26 ppm and 0.89 ppm showed the presence of CH₂ and CH₃ protons of OD. ¹³C NMR spectrum revealed the presence of 24 carbons suggestive of α- and β-anomers of OD-gal. Among 14 carbon peaks from each anomer, the 4 peaks at δ_C 31.4, 29.0, 22.3, and 13.7 ppm were assigned to be overlapped showing only 24 peaks out of a total of 28 peaks. The mass value from mass spectrometry analysis of OD-gal, and ¹H and ¹³C NMR spectral data were in good agreement with the expecting structure of OD-gal. Finally, we identified a galactose molecule from the hydrolysate of OD-gal using β-gal. We are expecting that through future study it will eventually be able to develop a safe cosmetic preservative.

• Archives of Pharmacal Research
• /
• v.18 no.1
• /
• pp.48-50
• /
• 1995

The $^1H NMR singls of three 6{\alpha}-bromopenicillanates$ have been assigned and the Nuclear Overthauser Effect(NOE) study of these compounds was undertaken.

• Food Science of Animal Resources
• /
• v.41 no.2
• /
• pp.312-323
• /
• 2021

The purpose of this study was to use 1H nuclear magnetic resonance (1H NMR) to quantify taste-active and bioactive compounds in chicken breasts and thighs from Korean native chicken (KNC) [newly developed KNCs (KNC-A, -C, and -D) and commercial KNC-H] and white-semi broiler (WSB) used in Samgye. Further, each breed was differentiated using multivariate analyses, including a machine learning algorithm designed to use metabolic information from each type of chicken obtained using 1H-13C heteronuclear single quantum coherence (2D NMR). Breast meat from KNC-D chickens were superior to those of conventional KNC-H and WSB chickens in terms of both taste-active and bioactive compounds. In the multivariate analysis, meat portions (breast and thigh) and chicken breeds (KNCs and WSB) could be clearly distinguished based on the outcomes of the principal component analysis and partial least square-discriminant analysis (R2=0.945; Q2=0.901). Based on this, we determined the receiver operating characteristic (ROC) curve for each of these components. AUC analysis identified 10 features which could be consistently applied to distinguish between all KNCs and WSB chickens in both breast (0.988) and thigh (1.000) meat without error. Here, both 1H NMR and 2D NMR could successfully quantify various target metabolites which could be used to distinguish between different chicken breeds based on their metabolic profile.

• Analytical Science and Technology
• /
• v.13 no.1
• /
• pp.49-54
• /
• 2000

The 8-hydroxyquinoline derivative of silica gel has been prepared through the 5 step reaction. We carried out infrared as well as nuclear magnetic resonance spectrometric characterization of products taken from each step of reaction. IR study of bare silica gel showed free and hydrogen bonded hydroxyl. From the 1st step reaction, we observed IR bands for N-H and C-H as well as NMR peaks for three methylene carbons in APTS group. From the 2nd step, we observed IR bands for carbonyl, nitro and aromatic carbon group with NMR peaks for aliphatic, aromatic and carbonyl carbons. The reduction of $NO_2$ group to $NH_2$ group is confirmed by IR and NMR from 3rd step reaction. In the last step, the immobilization of 8-quinolinol is confirmed by disappearance of $N{\equiv}N$ IR peak observed in 4th step.

• Korean Journal of Crystallography
• /
• v.12 no.3
• /
• pp.141-144
• /
• 2001

From the reaction of Na[Ga(N₃)₄] with PPh₃, an ionic compound [Ph₃P(OH)]/sup +/[N₃]/sup -/ (1) was isolated. Compound 1 was characterized by spectroscopy (¹H-NMR, /sup 13C{¹H}-NMR, and IR) and X-ray diffraction. Crystallographic data for 1 : orthorhombic space group P2₁2₁2₁, a = 10.491 (4) Å, b=11.603(5)Å, c=13.149(5)Å, Z=4, R(wR₂)=0.0547(0.0978).

• Archives of Pharmacal Research
• /
• v.20 no.3
• /
• pp.201-205
• /
• 1997

A very high content (at least 0.23%) of ergosterol peroxide was isolated from Naematoloma fasciculare Karst. Not only ergosterol peroxide but also ergosterol showed very strong anticomplementary activity on the classical pathway, the $IC_{50}$ values being $5.0 {\mu}M$ and $1.0 {\mu}M$, respectively. The $ ^{1}H $and $^{13}C$ NMR data of ergosterol peroxide were revised and completely assigned by DEPT, $^{1}H-^{1}H$ COSY, HMQC and HMBC correlations.

• Journal of the Korean Chemical Society
• /
• v.63 no.2
• /
• pp.78-84
• /
• 2019

High-resolution $^1H$ NMR spectroscopic technique has been widely used as one of the most powerful analytical tools in food chemistry as well as to define molecular structure. The $^1H$ NMR spectra-based metabolomics has focused on classification and chemometric analysis of complex mixtures. The principal component analysis (PCA), an unsupervised clustering method and used to reduce the dimensionality of multivariate data, facilitates direct peak quantitation and pattern recognition. Using a combination of these techniques, the various green teas and black teas brewed were investigated via metabolite profiling. These teas were characterized based on the leaf size and country of cultivation, respectively.

• Journal of Biosystems Engineering
• /
• v.21 no.3
• /
• pp.336-342
• /
• 1996

A 4.1MHz$1^H$ Nuclear Magnetic Resonance(NMR) sensor was designed and manufactured to evaluate the internal quality of fruits. The magnet console having 963gauss magnetic field induction was used for the NMR sensor. To optimize and evaluate the NMR sensor, glycerol and sugar-water solutions were used. $^1$H(proton) resonance signals were used to estimate the sugar contents in fruits. Artificial neural network models were developed to predict sugar contents in fruits from the proton resonance signals. The standard errors of prediction(SEP) were 0.565(apple), 0.394(pear) and 0.415(kiwi), respectively. The result implied that it was possible to evaluate apple, pear and kiwi into 3 grades using the NMR sensor.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1996.06c
• /
• pp.305-312
• /
• 1996

A 4.1MHz 1H Nuclear Magnetic Resonance (NMR) sensor was designed and manufactured to evaluate the internal quality of fruit. The magnet console having 963 gauss magnetic field induction was used for the NMR sensor. To optimize evaluate the NMR sensor, glycerol and sugar-water solutions were used. 1H(proton) resonance signals were use of to estimate the sugar contents in fruits the proton resonance signals and were validated . The standard errors of predictions(SEP) were 0.565(apple) , 0.394(pear) and 0.415(kiwi) respectively. The result implied that is possible to evaluate apple , pear and kiwi into 3 grades using the NMR sensor.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.24 no.5
• /
• pp.702-706
• /
• 1995

A major component(compound A) in the ethylacetate fraction exhibited a strong antimicrobial activity was identified by UV, IR, FABMS and NMR. The compound A showed strong absorbance at 209, 259 and 359nm, indicating a flavonoid ring structure. IR spectrum possessed absorbance of OH at 3400∼3300cm-1, ketone at around 1650cm-1, and aromatic C=C at around 1660cm-1. Molecular weight of the compound A calculated as 478 from the information of m/z 479(M＋H)+ and m/z 477(M-H)+ in the FABMS spectrum. Molecular formula of this compound was found to be C22H22O12 from m/z 479.1220(＋3.1mmu for C22H23O12) of HRFABMS spectrum and from 13C-NMR spectrum. 1H-NMR and 13C-NMR spectra of the compound A revealed aromatic proton and benzene rings. Distortionless enhancement by polarization transfer(DEPT) exhibited that the compound A possessed 10 quaternary carbons and 3 substituted benzene rings including a methoxy group substitution. The compound A was identified as isorhamnetin 3-O-β-glucopyranoside by spectrophotometric methods in conjunction with 1H-1H COSY, 1H-13C COSY and HMBC, which revealed a flavone with OH group at 3, 5, 7, and 4' and methoxy group at 3' positions esterified to glucose.