• The Plant Pathology Journal
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• v.15 no.3
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• pp.168-171
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• 1999

Crude extracts of pathogenic Streptomyces turgidiscabies isolates produced necrotic reaction on potato slices. Necrosis was first visible 24 hr after application and increased in severity over several days. However, necrosis was not observed when crude extracts of nonpathogenic strains were applied onto tuber slices. Presence of thaxtomin A from crude extracts of pathogenic S. turgidiscabies was identified by thin layer chromatography and high performance liquid chromatography. Nonpathgenic strains did not produce thaxtomin A in oatmeal broth. Inoculation of potato tuber slices with thaxtomin A partially purified from crude extract of a pathogenic S. turgidiscabies ST5 reproduce necrotic reaction suggesting that thaxtomin A is a pathogenicity determinant in S. turgidiscabies.

• Journal of Food Hygiene and Safety
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• v.3 no.3
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• pp.105-109
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• 1988

To develop a method for detecting and e&timating the quantity of adulterant rapeseed oil in sesame oil, five kinds of sesame oils and three kinds of rapeseed oils collected from different sources were fractionated by TLC (thin layer chromatography) and separated on the basis of PN (partition number) by HPLC (high performance liquid chromatography). These obsenations indicate that the proportion of adulterant rapeseed oil when mixed minimum 4% with sesame oil can be detected.

• Korean Journal of Pharmacognosy
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• v.43 no.3
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• pp.250-256
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• 2012

In order to extract the curcuminoid such as curcumin, demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC) in turmeric (Curcuma longa), solvent extraction methods (dipping and ultrasonic extraction method) and solid-phase extraction (SPE) were used. RP-HPLC (reverse-phase high-performance liquid chromatography) and TLC (thin-layer chromatography) were used for identification and analysis the three curcuminoid. From the experimental results, it is evident that the percentage of curcuminoid extracted from turmeric by ultrasonic extraction method was higher than dipping method. The percentage of curcumin extracted from turmeric by pure methanol was higher than any aqueous methanolic composition. Moreover, the total peak area of three curcuminoid was above 92% in RP-HPLC using solid-phase extraction. These results will form a database for investigating the constituents of natural products and the resources of pharmaceutical, nutrition, and cosmetic products.

• Korean Journal of Pharmacognosy
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• v.43 no.4
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• pp.286-290
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• 2012

Many diterpenoids from Siegesbeckia species (Compositae) and their anti-inflammatory actions have been examined. In this research, high-performance liquid chromatography-ultraviolet spectrophotometer (HPLC-UV) method was used to compare the quantitative level of kirenol (ent-pimarane-type diterpenoid) in the aerial parts of Korean S. glabrescens and S. pubescens and the Chinese Siegesbeckiae Herba. Fingerprints of the two HPLC chromatograms of Korean S. glabrescens and S. pubescens were similar, but considerably different from Chinese Siegesbeckiae Herba. The content of kirenol in S. pubescens ($16.51{\pm}0.10$ mg/ml dry weight as mean${\pm}$RSD) was higher than S. glabrescens ($13.48{\pm}0.12$ mg/g dry weight). These values were considerably higher than the Chinese Siegesbeckiae Herba ($1.55{\pm}0.74$ mg/g dry weight). Thin layer chromatography (TLC) analysis demonstrated the containing of kirenol in the three plant materials, but the presence of siegeskaurolic acid (entkaurane-type diterpenoid) only in the Chinese Siegesbeckiae Herba.

• Korean Journal Plant Pathology
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• v.11 no.1
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• pp.1-8
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• 1995

Alternaria alternata and A. solani were identified from 130 Alternaria isolates obtained from red pepper fruits, and three species including A. alternata, A. sesami and A. sesamicola were detected from 150 isolates from sesame seeds. Among the 4 Alternaria species, A. alternata was the predominant fungus from both plants, having incidence of 95.4% in red pepper and 56.0% in sesame. Of the total 280 isolates, cultures on autoclaved rice of 75 isolates were tested for toxicity to 21-day-old virgin female rats. Out of 50 isolates of A. alternata, 17 were lethal to rats, inducing congestion and hemorrhage of stomach and intestine and kidney enlargement, and 8 caused lack of weight gain or weight loss. The other 25 isolates of A. alternat and all the isolates of A. sesami, A. sesamicola and A. solani, showed no significant indication of toxicity. Production of mycotoxins in the rice cultures of the above 75 isolates belonging to 4 species was analyzed. Alternaria cultures were extracted with methanol and purified by using solvent partition, thin-layer chromatography, and high performance liquid chromatography. Of the four species tested, all produced alternariol (AOH) and alternariol monomethyl ether (AME), three (A. alternata, A. sesami and A. sesamicola) produced alternuene (ALT) and altertoxin-I (ATX-I), and only A. alternata produced tenuazonic acid (TA). TA was produced by all of the highly toxic (lethal to rats) isolates of A. alternata, but not by any nontoxic isolates.

• Korean Journal of Veterinary Service
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• v.19 no.1
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• pp.39-45
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• 1996

Sulfonamides are widely used to treat mastitis of cattle in field. The study was carried out to analyze sulfonamid residues In raw milk from south Kyeonggi area. The milk sample was deproteinated with acetone and defatted with hexane. The residual sulfonamides were extracted with ethylacetate, concentrated under vaccum, reconstituted with the acetate buffer-methanol mixture, reacted with fluorescamine, and then analyzed by HPLC-fluorescence detector(EX. 39nm, Em. 495nm) with methanol : acetate buffer system(3/2, v /v) as a mobile phase. The results analyzed by Thin layer chromatography and High performance liquid chromatography were summarized as follows. 1. A total of 24 cases out of 478 raw milk samples(5.0%) collected during April and May showed positive reaction to sulfonamide residues. Among 24 positive reactors, 9 cases were positive to sulfanilamides(32.1%), 8 cases were positive to sulfathiazoles(28.6%) and 5 cases were positive to sulfamonomthoxines (7.9%) , respectively. 2. During July and August, 31 cases out of 464 raw milk samples(6.7%) showed positive re action to sulfonamide residues. Among them S cases were positive to sulfanilamides, 5 cases sulfathiazoles and 5 cases sulfamonomethoxines(16.1%), respectively.

• Journal of Ginseng Research
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• v.38 no.1
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• pp.47-51
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• 2014

The transformation of ginsenoside Rb1 into a specific minor ginsenoside using Aspergillus niger KCCM 11239, as well as the identification of the transformed products and the pathway via thin layer chromatography and high performance liquid chromatography were evaluated to develop a new biologically active material. The conversion of ginsenoside Rb1 generated Rd, Rg3, Rh2, and compound K although the reaction rates were low due to the low concentration. In enzymatic conversion, all of the ginsenoside Rb1 was converted to ginsenoside Rd and ginsenoside Rg3 after 24 h of incubation. The crude enzyme (b-glucosidase) from A. niger KCCM 11239 hydrolyzed the ${\beta}$-($1{\rightarrow}6$)-glucosidic linkage at the C-20 of ginsenoside Rb1 to generate ginsenoside Rd and ginsenoside Rg3. Our experimental demonstration showing that A. niger KCCM 11239 produces the ginsenoside-hydrolyzing b-glucosidase reflects the feasibility of developing a specific bioconversion process to obtain active minor ginsenosides.

• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.619-622
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• 2006

Biotransformation is a good tool to synthesize regioselective compounds. It could be performed with diverse sources of genes, and microorganisms provide a myriad of gene sources for biotransformation. We were interested in modification of flavonoids, and therefore, we cloned a putative O-methyltransferase from Bacillus cereus, BcOMT-2. It has a 668-bp open reading frame that encodes a 24.6-kDa protein. In order to investigate the modification reaction mediated by BcOMT-2, it was expressed in E. coli as a His-tag fusion protein and purified to homogeneity. Several substrates such as naringenin, luteolin, kaempferol, and quercetin were tested and reaction products were analyzed by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). BcOMT-2 could transfer a methyl group to substrates that have a 3' functional hydroxyl group, such as luteolin and quercetin. Comparison of the HPLC retention time and UV spectrum of the quercetin reaction product with corresponding authentic 3'-methylated and 4'-methylated compounds showed that the methylation position was at either the 3'-hydroxyl or 4'-hydroxyl group. Thus, BcOMT-2 transfers a methyl group either to the 3'-hydroxyl or 4'-hydroxyl group of flavonoids when both hydroxyl groups are available. Among several flavonoids that contain a 3'- and 4'-hydroxyl group, fisetin was the best substrate for the BcOMT-2.

• Food Science and Biotechnology
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• v.17 no.6
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• pp.1322-1326
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• 2008

Tannase catalyzes the hydrolysis of gallic acid esters and hydrolysable tannins. Twenty-two Lactobacillus strains with tannase activity were isolated from 7 types of kimchi. A polymerase chain reaction-based assay targeting the recA gene assigned all isolates to either Lactobacillus plantarum or Lactobacillus pentosus. The tannase activities of isolates measured in whole cells and cell-free extracts varied even within each species. The activities of the isolates varied with the assay method, but both methods indicated that isolate LT7 (identified as L. pentosus) showed the highest activity. The results of thin layer chromatography and high performance liquid chromatography, respectively, showed that tannic acid and gallic acid degraded to pyrogallol in resting L. pentosus LT7 cells. Therefore, the putative biochemical pathway for the degradation of tannic acid by L. pentosus implies that tannic acid is hydrolyzed to gallic acid and glucose, with the formed gallic acid being decarboxylated to pyrogallol. This study revealed the possible production of pyrogallol from tannic acid by the resting cell reaction with L. pentosus LT7.

• Korean Journal of Agricultural Science
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• v.17 no.1
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• pp.52-64
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• 1990

As a search for natural antioxidants, antioxdative fractions in Pueraria roots were extracted, identified using column chromatography, thin layer chromatography or high performance liquid chromatography. The components which have most effective antioxidative activities were further identified by IR and GC-MS. Separated antioxidative components were then added to four different oils to examine their antioxidative activities. Yield of extract obtained from pueraria root powder by solvent extraction using four step solvent systems was 2.54%. Antioxidative activity of the extracts was as effective as that of 100 ppm ${\delta}$-tocopherol addition, when 0.1% of the extracts was added to linoleic acid. The strongest antioxidative component of methanol extract of pueraria root was identified as puerarin. Aunioxidative activity of puerarin on lard was more effective than ${\alpha}$-tocopherol, but less effective than ${\delta}$-tocopherol. When the puerarin was added to edible oil and heat treated at $145^{\circ}C$, the acid value was lowest in lard and was highest in soybean oil. Antioxidative activity in terms of carbonyl value, thiobarbituric acid value and anisidine value was most high in palm oil and least in soybean and cottonseed oil.