• Archives of Pharmacal Research
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• v.13 no.3
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• pp.215-220
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• 1990

Two different, derivative spectrophotometric and gas-liquid chromatographic, procedures for direct quantitation of caffeine and some commonly dispensed antihistaminics in bulk forms, in their laboratory prepared mmixtures and in dosage formulations, have been investigated. The limit, sensitivity reproducibility and accuracy of each method were studied for each individual drug substance and in some usual pharmaceutical formulations.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.945-949
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• 1994

Chondroitin sulfate (Chs) contents in edible snail , Achatina fulica Bowdich , andits processed meat extracts were determined by high-performance liquid chormatogrpahy(HPLC) and spectrophotometric method. Spectrophotometric method was based on the precipitation of acriflavine by ChS, and HPLC method was based on the detection of two unsaturated disaccharides, 2-acetamido-2-deoxy-3-O-($\beta$ -D-gluco-4-enepyranosyluronic acid)-4-O-sulfo-D-galactose($\Delta$Di-4S) and 2-acetamido-2deoxy-3-O-($\beta$-D-gluco-4-eepyranosyluronic acid)-6-O-sulfo-D-galactose ($\Delta$야-6S) librated from ChS byenzymeatic digestion with chondroitinase ABc. the ratio of 125$\mu$mol of sodium hydroxide to mg of ChS and 8$0^{\circ}C$ of reaction temperature were proper for alkaline hydrolysis to remove protein residue form ChS. In assay preparation for HPLC ethod, the iptimum concentration of the enzyme chondroitinase ABc was 0.15 unit per 50 $\mu\textrm{g}$ of ChS at a fixed reaction time (30 min) and pH 8.0 using Tris buffer. ChS content in edible snail was 177.6mg% by spectrophotometric method and 153.5mg% by HPLC method and those in the processed meat extract was 71.3mg% by spectrometric method ad 62.8mg% by HPLC method, respectively.

• BMB Reports
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• v.38 no.3
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• pp.366-369
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• 2005

NADPH-cytochrome P450 reductase (CPR) transfers electrons from NADPH to cytochrome P450 and also catalyzes the one-electron reduction of many drugs and foreign compounds. Various spectrophotometric assays have been performed to examine electron-accepting properties of CPR and its ability to reduce cytochrome $b_5$, cytochrome c, and ferricyanide. In this report, reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) by CPR has been assessed as a method for monitoring CPR activity. The principle advantage of this substance is that the reduction of MTT can be assayed directly in the reaction medium by a continuous spectrophotometric method. The electrons released from NADPH by CPR were transferred to MTT. MTT reduction activity was then assessed spectrophotometrically by measuring the increase of $A_{610}$. MTT reduction followed classical Michaelis-Menten kinetics ($K_m\;=\;20\;{\mu}M$, $k_{cat}\;=\;1,910\;min^{-1}$). This method offers the advantages of a commercially available substrate and short analysis time by a simple measurement of enzymatic activity of CPR.

• Journal of Microbiology and Biotechnology
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• v.4 no.4
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• pp.360-363
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• 1994

A colorimetric assay for $\gamma$-glutamyl transpeptidase ($\gamma$-CTP; E.C 2.3.2.2) employing 2, 4, 6-trinitrobenzene sulfonate (TNBS) to detect the amount of disappeared acceptor via transpeptidation, has been developed. Under the experimental conditions using L-$\gamma$-glutamyl ethyl ester and L-phenylalanine as $\gamma$-glutamyl donor and acceptor, respectively, it was found that the decreased absorbance of yellow color at 420 nm was strictly related to the amount of L-$\gamma$-glutamyl-L-phenylalanine (L-$\gamma$-Glu-L-Phe) formed, which was determined by DEAE-cellu-lose column chromatography. Concentrations of the enzyme and $\gamma$-glutamyl products were able to be determinedin the nanogram and nanomoles per milliliter range, respectively, with high precision and reliability. This novel assay system may therefore be a useful means for understanding of catalytic function of the $\gamma$-CTP spectrophotometrically without any usage of sophisticated instruments.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.22 no.1
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• pp.84-101
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• 1996

To minimize the use of animals in toxicity testing, and to reduce the cost in vivo test, more rational test method was described which determines, in the same animal, photoxic and photoallergic potential of a substance, and is daptable to routine testing. The other purpose of this study was to investigate the usefulness of in vivo alternatives ; photostability and spectrophotometric carbonyl assay. In this modified photosensitization model, animal numbers and resting periods, the number and method of topical application were simplified. Two positive photoreactive agents, Benzocaine and 6-methyl coumarine, showed a similar photoallergic potential to that of Ichikawa's method. Two sunscreens, Octyl methoxy cinnamate, Butyl methoxyl dibenzoyl methane, hardly showed photoallergic potentials. The photostability test could be used in the step of prescreening of photosensitization potential because most of the photoreactive agents represented the reduction of more than 20% in the absorbance. And photoreactive agents have a high potential of photosensitization in the sddessment of spectrophotometric carbonyl level although two sunscreens have a low possibility of photosensitization. Therefore this method was assumed as a valuable in vivo alternatives in the respect even in the very low concentrations which phototoxicity test using almonella showed no phototoxic potential.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.345-348
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• 2002

A rapid spectrophotometric method for detecting the mucinase complex was developed. Bovine submaxillary mucin is cleaved by commercial mucinase between the oligosaccharide chain and the side chain of peptide linkage, thereby liberating the N-acetyl neuraminic acid (NANA). The release of NANA resulted in an increase of absorbance at 280 nm. The susceptibility to NANA by the new method was found to be at least 10-fold more sensitive than the thiobarbituric acid method. Moreover, the quantification of NANA released from mucin by commercial neuraminidase and partially purified Vibrio parahaemolyticus mucinase showed a good linear correlation in proportion to the concentration of the enzyme used. These results demonstrate that the rapid identification of mucin degradation can be determined by a spectrophotometric assay, thereby providing a new, fast, and sensitive method for assaying the bacterial mucinase complex.

• BMB Reports
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• v.37 no.5
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• pp.629-633
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• 2004

NADPH-cytochrome P450 reductase (CPR) transfers electrons from NADPH to cytochrome P450, and catalyzes the one-electron reduction of many drugs and foreign compounds. Various forms of spectrophotometric titration have been performed to investigate the electron-accepting properties of CPR, particularly, to examine its ability to reduce cytochrome c and ferricyanide. In this study, the reduction of 1,1-diphenyl-2-picrylhydrazyl (DPPH) by CPR was assessed as a means of monitoring CPR activity. The principle advantage of DPPH is that its reduction can be assayed directly in the reaction medium by a continuous spectrophotometry. Thus, electrons released from NADPH by CPR were transferred to DPPH, and DPPH reduction was then followed spectrophotometrically by measuring $A_{520}$ reduction. Optimal assay concentrations of DPPH, CPR, potassium phosphate buffer, and NADPH were first established. DPPH reduction activity was found to depend upon the strength of the buffer used, which was optimal at 100 mM potassium phosphate and pH 7.6. The extinction coefficient of DPPH was $4.09\;mM^{-1}\;cm^{-1}$. DPPH reduction followed classical Michaelis-Menten kinetics ($K_m\;=\;28\;{\mu}M$, $K_{cat}\;=\;1690\;min^{-1}$). This method uses readily available materials, and has the additional advantages of being rapid and inexpensive.

• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.161-175
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• 1996

There were many reports that elevations in the levels of active and latent collagenase in gingival crevicular fluid(GCF) have been correlated positively with periodontal disease activity. To provide a simple diagnostic approach for testing GCF collagenolytic activity, the detection limit of enzyme activity was compared using radiofibril assay(Sodek et.al.1981) and spectrophotometric collagenolytic assay(Nethery et al. 1986). The detection limits of both assay for standard bacterial enzyme were similar and the radiofibril assay showed a little (1/2) lower detection limit for tad pole collagenase. To evaluate the relationship between periodontal tissue destruction and the collagenolytic activity, GCF was collected, and latent and active enzyme activities were measured by a spectrophotometric collagenolytic assay. Twelve subjects showing progressive lesions were selected according to the presence of immediate tissue destruction, frequent abscess formation, and increasing need for tooth extraction, and the absence of underlying systemic disease and previous antibiotic medication history within 6 months. Comparisons were made between sites with either: 1) inflammation with a previous history of progressive loss of periodontal tissue and bone support(2l progressive sites): 2) previous history of bone loss and periodontal destruction but now clinically stable(12 comparably stable sites); or 3) no loss of periodontal tissue and bone support(11 control sites including 5 gingivitis sites and 6 healthy sites). Active collagenase activity was the highest in the progressive sites and decreased in the order of the gingivitis sites, the stable sites, and the healthy sites. The total enzyme activity was $2{\sim}3$ fold higher in the progressive sites and the gingivitis sites, compared to the stable and the healthy sites. The ratio of active to total collagenolytic activity was twice in the progressive sites. Analysis of active collagenase level(5mU) and the ratio of active to total collagenolytic activity(0.8) as a diagnositic test indicates that these measurements have the sensitivity of 0.81 and 0.86, the specificity of 0.70 and 0.65, and the overall agreement of 0.75 and 0.73, respectively. Thus, this method has significant merits as a diagnostic tool to determine wherher the site is in a state of remission or progression.

• Korean Journal of Plant Resources
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• v.29 no.5
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• pp.588-597
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• 2016

Little attention has been paid to the functional aspect of the flower petal of Paeonia lactiflora, compared to that of its root. To determine the components of flower petal of Paeonia lactiflora, we conducted the Fourier transform ion cyclotron resonance (FT-ICR) MASS spectrophotometric analysis. We detected the 24 different types of ingredients from the 70% ethanol extracts of flower petal of peonia lactiflora cv. ‘Red Charm’. The main compounds were quercetin glucopyranosides, methyl gallate, paonioflolol and kaemperol glucopyranosides. We further tested its functional activity. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the extracts was 87.9-90.4% at 0.1mg/ml. This result showed that these flower extracts have approximately 5-fold stronger antioxidant potential than a previous report with root extracts (Bang et al. 1999). The result of tyrosinase inhibition assay of Paeonia lactflora extract was almost similar to that of arbutin except significantly higher effect in the coral sunset extract at 0.1% concentration. Hyaluronidase inhibition assay showed 76.5% inhibition at 5% concentration of this flower extract, indicating that Peaonia lactiflora flower extracts have the major anti-inflammatory, anti-oxidant and brightening effects. Taken together, these results suggest these three Paeonia lactiflora species extracts might provide the basis to develop a new natural brightening agent.

• Preventive Nutrition and Food Science
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• v.1 no.2
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• pp.196-202
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• 1996

The effect of cooking(boiling, steaming and baking0and drying on the cholesterol content and formation of oxidized cholesterols in quid(Japanese flying squid, Todarodes pacificus) was studied. Cholesterol content of live squid meat varied with the portion sampled, and results from spectrophotometric assay ranged from 263.2mg/1..g(mantle) to 315.8mg/100g(tentacle). The cholesterol levels analyzed by gas chromatography(GC) for squid samples were lower by 7% of total cholesterol for live squid meat and 24% for processed meat than those results by spectrophotometric assay. Cooking resulted in the decrease of the initial total cholesterol content of raw meat from 10%(boiling for 5min.) to 25%(steaming for 5min.) The amounts of cholesterol remaining after baking were 68% for microwave oven samples and 64% for convection oven samples. Drying of raw tissue caused the greater reduction in cholesterol content than cooking but showed no significant difference in samples stored for 6 weeks at 4$^{\circ}C$ and 2$0^{\circ}C$. Raw squid meats contained essentially no oxidized cholesterols, while the 22-hydroxychoesterol was detected in frozen meats. The additional oxidized cholesterols as cholestane-triol was indentified with 22-hydroxycholesterols in cooked samples. Sun dried meat stored at 4一 and 2$0^{\circ}C$ for 6 weeks had the three kinds of oxidized cholesterols such as 22-hydroxycholesterol, cholesta-3,5-dien-7-one and cholestane-triol.