• Journal of Plant Biotechnology
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• v.29 no.1
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• pp.19-23
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• 2002

This experiment was conducted to micropropagate bulblets via shoot cluster formation and massproduce normal bulblets from the sections of proliferated shoot clusters in Lilium asiatic hybrid 'Hae Hwa'. The induction of shoot clusters from the culture of bulblet sections was more effective than that of bulb scales on MS medium with 1.0 mg/L BA and 0.5 mg/L IAA. Proliferation of shoot clusters from the formed shoot cluster sections was the most favorable on medium containing 5.0 mg/L BA and 0.5 mg/L IAA. The formation and the growth of bulblets from shoot cluster sections were achieved effectively on medium with 60∼90 g/L sucrose. The leaves derived from shoot clusters grew vigorously but the bulblets from shoot clusters grew very poor in 5L air-lift bioreactor culture. By the addition of 30 mL fresh liquid medium containing doulble strength MS salts, 250 g/L sucrose and 5 g/L activated charcoal after 8 weeks in the shoot cluster culture on MS medium with 5.0 mg/L BA and 0.5 mg/L IAA, the number of bulblets was increased in light condition, but the growth of bulblets was not affected by light. Bulblet production was possible with the bulblet product at 53 to 68 mg in fresh weight by liquid medium addition after the proliferation of shoot cluster.

• Korean Journal of Medicinal Crop Science
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• v.2 no.1
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• pp.60-66
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• 1994

This study was conducted to determine the optimum conditions of inducing callus, proliferating callus, forming somatic embryos, and regenerating plantlets via somatic embryogenesis, for the purpose of producing artificial seeds and substantially developing plant factory technologies that can be employed to all seasons production of Bupleurum plants. Callus was efficiently induced from leaf tissues at three leaf stage in the MS medium supplemented with 2, 4-D 2mg /1 and thidiazuron(TDZ) 0.lmg /1. Callus induction from leaf tissues at maturity was mostly effective in the mixture of 2,4- D 2mg /1 and TDZ 1.0mg /1 while that from flower bud tissues was fairly good in the MS medium containing 2,4-D 1 or 2mg /1.Callus was formed in 15 to 20 days after culture initiation in the MS media supplemented with 2, 4- D 1-2mg /1 and TDZ 0.l-1.0mg /1. Such hormones as kinetin 3mg /1, GA 1mg /1, and the mixture of GA 1mg /1 and TDZ 1mg /1 effected markedly to proliferate the callus cells.The optimum temperature and light intensity for callus culture were found to be $25^{\circ}C$ and 3000 Lux, respectively. Direct plant regeneration from cultured callus was fairly made on hormone-free MS or half-strength MS medium. Somatic embryogenesis was most frequently observed in hormone-free media:60 somatic embryos per 20ml in MS medium and 28 somatic embryos per 20ml in half -strength MS medium. There were three stages-globular, heart, and torpedo-in development of somatic embryos, among which globular stage was more frequently observed in MS medium rather than in half-strength MS medium. Somatic embryos induced from suspension culture fairly differentiated a number of shoots and roots on hormone-free and half-strength MS solid medium.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.296-313
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• 2014

A QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) multiresidue method was developed for the simultaneous analysis of 124 pesticides in soil by LC-MS. The procedure involved liquid extraction of soil immersed with 0.2N $NH_4Cl$ by acetonitrile with 1% acetic acid, followed by anhydrous $MgSO_4$ and sodium acetate, and dispersive SPE cleanup with $MgSO_4$, primary secondary amine (PSA) and $C_{18}$. The extracts were analyzed with LC-MS/MS in ESI positive mode. Standard calibration curves were made by matrix matched standards and their correlation coefficients were higher than 0.99. Recovery studies for the validation were carried out using two type soils, loam and sandy loam, at four concentration levels (0.005, 0.01, 0.02, and 0.1 mg/kg). The recoveries of pesticides were in the range of 70-120% with < 20% RSD except 4 pesticides, Benfuracarb, Ethiofencarb, Pymetrozine, and Pyrethrin. This result indicated that the method using QuEChERS and LC-MS/MS could be applied for the simultaneous determination of pesticide residues in soils.

• The Korean Journal of Mycology
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• v.39 no.3
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• pp.239-242
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• 2011

Eritadenine, a potent compound of hypocholesterolemic activity, was investigated in relation to its content in domestic cultivars and wild types of shiitake (Lentinula edodes). Eighteens strains of shiitake were tested for the quantification of eritadenine by LC-MS/MS analysis. Among the strains, wild type-40 was highest as the content was 3.912 mg/g. Also, Soohyangko was 3.352mg/g, Sanlim No. 9 3.008mg/g, Chunbaegko 2.832 mg/g, Gaeulhyang and KFRI 675 both 2.792 mg/g as high-content strains. Soohyangko and Chunbaegko are applied strains for registration in 2010. Soohyangko is high-temperature type with concentrated fruiting, and 90% of production occurs in the first year, thus, recovery of cost is very fast. Chunbaegko is mid-temperature type with concentrated flushing, and produces "hwago", the best quality, in spring. Wild type-40 is excellent in productivity and is prepared for registration. Wild type-40 could be used as parent strain to make new strain with high eritadenine content.

• Journal of Plant Biotechnology
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• v.30 no.4
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• pp.381-385
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• 2003

An efficient method of plant regeneration from Acanthopanax chiisanensis somatic embryos was developed. Cotyledonary somatic embryos were obtained in liquid Murashige and Skoog (MS) medium from embryogenic cell suspension cultures. They were desiccated for 0 to 72 hr and then cultured on MS medium containing NAA, BA, GA$_3$, (0-0.5mg/L). The highest multiple shoots formation (100％) was obtained from 72 hr desiccated somatic embryos on ifs medium with 0.5mg/L NAA＋0.5mg/L BA or 0.5 mg/L NAA＋0.5mg/L BA＋0.5mg/L GA$_3$ after 6 weeks culture. Plant conversion from multiple shoots was not high. The highest plant conversion from multiple shoots was obtained on 1/3MS medium with 1.0mg/L GA$_3$. Converted plantlets were transferred to ex vitro condition and the highest survival rate (70％) of the plantlets was obtained on plastic pots containing vermiculite and sand. These results indicate that micropropagation procedure can be applied for an efficient mass propagation of Acanthopanax chiisanensis.

• Korean Journal of Food Science and Technology
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• v.40 no.1
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• pp.8-14
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• 2008

This study was performed to establish analysis methods, and evaluated for grayanotoxin in domestic/foreign honey and wild honey. The molecular weight of grayanotoxins I, II and III, excluding grayanotoxin III that has been commercialized, were analyzed by LC-MS/MS. Then, the molecular structure of grayanotoxins I and II were analyzed by NMR. A total 111 samples (25 Korean honey, 21 Korean wild honey, 13 Korean honeycomb honey, 44 foreign honey, 8 foreign wild honey) were examined to determined whether or not each sample contained grayanotoxins I, II, and III. The honey samples were mixed with methanol and loaded into a tC18 cartridge, the filtrate was diluted with water, and the mixture was then analyzed by ESI triple-quadrupole LC-MS/MS. Grayanotoxins were only found in the foreign wild honey and were not detected in Korean honey, Korean honeycomb honey, or Korean wild honey. Three of the samples contained grayanotoxin I, II, and III, and one sample contained only grayanotoxins I and III. The lowest level for grayanotoxin I was 3.13 ${\pm}$ 0.00 mg/kg, and the highest level was 12.93 ${\pm}$ 0.01 mg/kg. The levels of grayanotoxin II were 0.84 ${\pm}$ 0.01 mg/kg, 0.92 ${\pm}$ 0.00 mg/kg and 1.08 ${\pm}$ 0.01 mg/kg, respectively. The lowest level of grayanotoxin III was 0.25 ${\pm}$ 0.01 mg/kg and the highest level was 3.29 ${\pm}$ 0.74 mg/kg. Through this study, safety management for foreign wild honey has been enabled.

• Journal of Plant Biotechnology
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• v.30 no.1
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• pp.109-113
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• 2003

Cryopreservation of embryogenic callus derived from apical meristem culture was attempted by slow prefreezing method (two-step method) with various cryoprotectants in sweetpotato cv. 'Yulmi' Precultured embryogenic calli on medium containing 10 mg/L ABA prior to slow prefreezing in liquid nitrogen indicated higher survival rate than 1.0 mg/L ABA preteatment. The cryoprotectant comprising 1.28 M DMSO in 0.4 M sucrose solution gave the best survival (over 46%) of sweetpotato cells exposed to liquid nitrogen as determined by TTC reduction and FDA staining method. Cryopreserved calli cultured on MS medium with 1.0 mg/L 2,4-D were grown for 4 weeks in the dark and induced embryos after another 4 weeks. They were subcultured on MS medium supplemented with 0.1 mg/L 2,4-D＋0.1 mg/L kinetin for 2 weeks and regenerated into normal plantlets in MS basal medium.

• Journal of Plant Biotechnology
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• v.35 no.3
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• pp.203-208
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• 2008

In order to micropropagate uniform plantlets of Philodendron cannifolium in vitro, the shoot tips were cultured on MS media supplemented with $0.5{\sim}10.0$ mg/L BA or $0.05{\sim}0.1$ mg/L thidiazuron(TDZ). The adventitious multi-bud clusters from basal part of shoots were formed on MS media containing $2.0{\sim}5.0$ mg/L BA or $0.05{\sim}0.1$ mg/L TDZ. But the shoots grown on MS media with TDZ showed necrosis by the lack of chlorophyll. The adventitious multi-bus clusters were cut into $5{\sim}7$ mm sections and cultured on MS media containing BA and TDZ for shoot proliferation. Shoots were proliferated vigorously on MS medium supplemented with $1.0{\sim}3.0$ mg/L BA with up to 30 shoots. But abnormally swollen hard calli were formed from basal parts of shoots on MS media with TDZ and high concentration of BA(10.0 mg/L). The proliferated shoots on same media also showed necrosis by the lack of chlorophyll. The shoot growth and rooting were favorable on MS media containing $0.5{\sim}2.0$ mg/L IBA. The rooted plantlets were acclimatizated effectively in soil mixed with perlite 1:vermiculite 1 or vermiculite alone. Fifteen mL of liquid medium containing 10 g/L activated charcoal and 30 g/L sucrose were added in same vessels after small shoots were proliferated to stimulate shoot growth and rooting. After 8 weeks in culture, the shoots were dipped into high concentration of IBA solution. and planted in soil mexed with perlite 1:vermiculite 1. The shoot growth and rooting were favorable in dipping treatments of $500{\sim}2,000$ ppm IBA solutions for 10 sec.

• Analytical Science and Technology
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• v.22 no.3
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• pp.210-218
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• 2009

A gas chromatography-tandem mass spectrometry (GC-MS/MS) method was developed and validated for simultaneous determination of amphetamine derivatives and norketamine in human hair. Preparation of hair involves external decontamination, mechanical pulverization, incubation and extraction prior to instrumental analysis. The samples were derivatized using heptafluorobutyric anhydride, and analyzed by GC-MS/MS. The linear ranges were 0.05-20.0 ng/mg for the analytes except for 3,4-methylenedioxyamphetamine, with good coefficients of determination ($r^2$ >0.998). The intra-day and inter-day precisions were within 10.7% and 8.5%, respectively. The intra-day and inter-day accuracies were between -1.6 and 17.0% and -2.6 and 10.5%, respectively. The limits of detections for each analyte were lower than 0.007 ng/mg, while recoveries were 75.9-100.9%. When the method was applied to hair samples obtained from suspected drug abusers, the concentrations in hair samples were 0.97-19.30 ng/mg for methamphetamine and 0.14-2.56 ng/mg for amphetamine.

• Journal of Plant Biotechnology
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• v.37 no.1
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• pp.84-88
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• 2010

To establish the system of In vitro plant regeneration, the floral bud and leaf explants of Sedum rotundifolium were cultured on the MS media supplemented with different concentration of 2,4-D, NAA, and BA. The callus induction was more effective in the floral explants than the leaf explants, and was the best on MS medium containing 1.0 or 2.0 mg/L 2,4-D and 1.0 mg/L BA. The highest numbers of shoots were regenerated when callus were cultured on MS medium containing 2.0 mg/L 2,4-D and 1.0 mg/L BA for 8 weeks. The normal root formation from shoot was effective on the MS medium containing IAA alone. The regenerated plantlets were transferred to the pot and acclimatized successfully.