• Horticultural Science & Technology
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• v.28 no.5
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• pp.750-756
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• 2010

This study was performed to investigate the role of phytohormones in the bulbing of garlic in order to assess the yield and quality. The effect on endogenous plant hormones such as gibberellin (GA) content was also examined during growth stage i.e. clove differentiation to bulbing in garlic. More than 18 gibberellins in garlic were identified with extensive gas chromatograph-mass spectrometry-selected ion monitoring (GC-MS-SIM) quantitative analysis. The results showed that GAs were biosynthesized by both non C-13 hydroxylation pathway (NCH) and early C-13 hydroxylation pathway (ECH) in garlic plant. It was also revealed that NCH pathway leading to synthesis of bioactive $GA_4$ was the more prominent GA biosynthesis pathway than ECH pathway in which bioactive $GA_1$ was synthesized. Total GAs level was gradually increased from clove differentiation to bulbing and later decreased, which portrays the active role of GA in differentiation. The biosynthesis ratio of bioactive $GA_4$ and $GA_1$ concentration was similar to that of total GAs content, which was closely related with bulb development in garlic.

• Analytical Science and Technology
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• v.35 no.2
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• pp.53-59
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• 2022

Mugwort (Artemisia montana), which is a perennial plant mainly distributed throughout Northeast Asian regions, has been used as a preferred source of various foods and traditional medicines in Korea. In particular, as essential oils extracted from mugwort were reported to be biologically active, its steam distillate has been widely used to treat various conditions, such as itching, hemorrhoids, and gynecological inflammation. Therefore, efforts have been devoted to develop effective methods for the collection of bioactive essential oils from mugwort. In this study, five mugwort extracts were obtained using different extraction conditions, namely, 6 % ethanol at room temperature and at 80 ℃, pure ethanol, n-hexane, and an adsorbent resin. To evaluate the five extracts of mugwort, area-under-the-curve values (AUCs), chemical profiles, and major bioactive essential oil contents were investigated using gas chromatography-mass spectrometry (GC-MS). An overall assessment of the volatile components, including essential oils, in the five extracts was conducted using AUCs, and the individual essential oil in each extract was identified. Furthermore, the four major essential oils (1,8-cineole, camphor, borneol, and α-terpineol), which are known to possess anti-microbial and anti-inflammatory activities, were quantified using authentic chemical standards. Based on the evaluation results, pure ethanol was the best extractant out of the five used in this study. This study provides evaluation results for the five different mugwort extracts and would be helpful for developing extraction methods to efficiently collect the bioactive oil components for medical purposes using chemical profiles of the extracts.

• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.1979-1984
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• 2014

We have developed an efficient method to generate highly active Pd and PdO nanoparticles (NPs) dispersed on graphene and graphene oxide (GO) by an impregnation method combined with thermal treatments in $H_2$ and $O_2$ gas flows, respectively. The Pd NPs supported on graphene (Pd/G) and the PdO NPs supported on GO (PdO/GO) demonstrated excellent carbon-carbon cross-coupling reactions under a solvent-free, environmentally-friendly condition. The morphological and chemical structures of PdO/GO and Pd/G were fully characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). We found that the remarkable reactivity of the Pd/G and PdO/GO catalysts toward the cross-coupling reaction is attributed to the high degree of dispersion of the Pd and PdO NPs while the oxidative states of Pd and the oxygen functionalities of graphene oxide are not critical for their catalytic performance.

• Journal of Crop Science and Biotechnology
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• v.10 no.4
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• pp.281-286
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• 2007

Gibberellins are growth hormones that play a pivotal role in the growth and development of plants. Present investigations were carried to check the effect of nitrogen(N) and silicon(Si) on bioactive $GA_1$ and its immediate precursor $GA_{20}$ at different growth stages of two rice cultivars with different maturity traits. It was observed that the endogenous bioactive $GA_1$ level gradually increased during vegetative stage and anthesis stage of both Junghwabyeo(early flowering cultivar) and Daesanbyeo(late flowering cultivar). However, the $GA_1$ and $GA_{20}$ content start decreasing during the seed filling stage in both rice cultivars, which indicated a possible relationship of bioactive $GA_1$ and floral development. Our results also confirmed that early 13-hydroxylation pathway was operated at all developmental stages of rice plant. Variation in the levels of the endogenous gibberellins in rice shoots were measured by GCMS-SIM using $^2H_2$-labeled gibberellins as internal standards. Combined application of N and Si enhanced growth parameters and reduced lodging index of both rice cultivars. It was thus concluded that the level of physiologically active $GA_1$ increased during vegetative and early reproductive stage, but starts declining at seed filling stage.

• Korean Journal of Environmental Agriculture
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• v.36 no.1
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• pp.17-21
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• 2017

BACKGROUND: Castor oil and wormseed extract are important active ingredients for biopesticide, and ricinoleic acid in castor oil and three monoterpenes (ascaridole, carvacrol and p-cymene) in wormseed extract are known bioactive substances. However, their stabilities had not been studied, even though the stability was the core property for estimation of shelf-life of biopesticide. Aimed to investigate the thermal stabilities of the bioactive substances in castor oil and wormseed extracts. METHODS AND RESULTS: The contents of ricinoleic acid and three monoterpenes (ascaridole, carvacrol and p-cymene) were analyzed by gas chromatography (GC). The thermal stabilities of the bioactive substance were measured at $0^{\circ}C$, $23^{\circ}C$, $30^{\circ}C$, $40^{\circ}C$, $45^{\circ}C$ and $54^{\circ}C$ for 84 d. The half-lives of ricinoleic acid in biopesticides was ranged from 28.9 d to 57.8 d at $30^{\circ}C$, and the stability of pure castor oil were located in the range ($t_{1/2}$=46.2d for Indian product and 27.7 d for Korean product) at the same temperature. The half-lives of the total monoterpenes in biopesticides were ranged from 3.9 d to 27.7 d at $30^{\circ}C$. Among the monoterpenes, the stability ascaridole and p-cymene were decreased in acidic condition. All the bioactive substances showed similar stability on the different thermal conditions. CONCLUSION:The half-lives of most bioactive substance from castor oil and wormseed extracts were less than 100 d. To increase the stability of bioactive substance in biopesticide, stabilizing additives like antioxidant and oxygen remover should be considered to extend of the shelf-life.

• Mycobiology
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• v.47 no.3
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• pp.335-339
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• 2019

Endophytic fungi have the ability to live inside the host plant tissues without causing neither symptoms of diseases/or harm. Opportunistic infections are accountable for majority of the outbreaks, thereby putting a burden on the health system. To investigate and characterize the bioactive compounds for the control of bacteria of clinical importance, extracts from endophytic fungi were isolated from indigenous South African medicinal plants. Extracts from endophytic fungi were isolated from 133 fungal strains and screened against Gram positive and negative bacteria namely Bacillus cereus, Escherichia coli, Enterococcus faecium, and E. gallinarum using disk diffusion. Furthermore, gas chromatography-mass spectrometry was performed to identify the bioactive compounds. Sixteen out of one hundred and thirty-three (12%) fungi extracts exhibited antibacterial properties against some of the selected bacteria. E. coli was found to be the most susceptible in contrast to E. faecium and E. gallinarum which were the most resistant. The isolate MHE 68, identified as Alternaria sp. displayed the greater spectrum of antibacterial activities by controlling selected clinical bacteria strains including resistant E. faecium and E. gallinarum. The chemical analysis of the extract from MHE 68 indicated that linoleic acid (9,12-octadecadienoic acid (Z,Z)) and cyclodecasiloxane could be accountable for the antibacterial activity. This is the first study conducted on the secondary metabolites produced by endophytic fungal strains isolated from the Pelargonium sidoides DC. possessing antibacterial properties.

• Journal of Sericultural and Entomological Science
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• v.43 no.2
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• pp.109-115
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• 2001

Silk sericin protein was extracted by treatment with enzyme or NaOH solution from raw silk and culled-cocoon shell. The extracted sericin was characterized and examined the functional properties as well as subjective properties for its use as a soap and a body cleaner. The optimum extraction conditions on specimen are NaOH (0.02 wt.%) or enzyme, Flavourzyme 3% under N2 gas. Molecular weights of sericin was decreased by treatment with enzyme, Actinase, from 10,000-30,000 to 2,700-4,200. Sericin showed important bioactive properties, for instance, lowering effect on blood glucose and alcohol. Subjective test of sericin soap and body cleaner showed superior in washability, foamability, and skin hydration, etc., to commercial soap and body cleaner. Therefore, it is thought that silk sericin can be expected as the source of bioactive and skin-compatible materials.

• Journal of Crop Science and Biotechnology
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• v.10 no.3
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• pp.163-166
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• 2007

Diurnal changes in levels of endogenous gibberellins(GAs) were investigated in three rice cultivars i.e. Sangjubyeo, Shingeumobyeo(photo-neutral) and Chucheongbyeo(photosensitive). The rice cultivars were grown under a 12-hr photoperiod and endogenous GA levels were assayed by gas chromatography-mass spectrometry(GC-MS-SIM) every 3 h for 24 h. The endogenous bioactive $GA_1$ and its immediate precursor $GA_{20}$ contents were significantly different in both photosensitive and photo-neutral rice cultivars, though less pronounced differences were observed for endogenous $GA_{12},\;GA_{53},\;GA_{19}$, and $GA_8$ levels with in the three rice cultivars. The levels of bioactive $GA_1$ and its immediate precursor $GA_{20}$ were significantly higher in Chucheongbyeo than in the other two cultivars. In Chucheongbyeo, the $GA_1$ contents increased significantly from 11.00 to 17.00 o'clock, thus indicating a correlation with light. In Shingeumobyeo, $GA_1$ contents slightly increased during morning hours, while a similar hike in $GA_1$ contents was observed for Sangjubyeo during evening hours. $GA_{19}$ was found to be the most abundant GA form in the three rice cultivars. Our results suggested that GA production in rice depends upon the response potential of rice cultivars and that light positively correlated to GA production in photosensitive rice cultivar.

• Journal of Crop Science and Biotechnology
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• v.11 no.4
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• pp.223-226
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• 2008

Seedlings of two rice cultivars i.e. cv. Daesanbyeo and cv. Dongjinbyeo were analyzed for growth and endogenous gibberellins (GAs) in response to nitrogen nutrition applied in the forms of $KNO_3$, $(NH_4)_2SO_4$ and $NH_4NO_3$. All the growth parameters showed an increase in N applied treatments and their magnitudes of increase were different depending on different nitrogen fertilizer forms. The endogenous GAs contents were increased with N application but differentially affected by various N-forms in both rice cultivars. In cv. Daesanbyeo, maximum amount of bioactive $GA_1$ was recorded for $(NH_4)_2SO_4$, while maximum amount of bioactive $GA_1$ in cv. Dongjinbyeo was observed in $NH_4NO_3$ applied treatments. In both rice cultivars, $KNO_3$ applied rice plants contained least $GA_1$ contents. Also, $GA_{19}$ was the most abundant GA found in rice seedlings whereas $GA_4$ was absent at seedling stage. Our study indicated that different rice cultivars showed different responses for the same fertilizer depending upon the response potential of each cultivar and the pertinent physiological responses to changes of endogenous GAs in rice cultivars, which were comparatively lesser in magnitude.

• Herbal Formula Science
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• v.24 no.2
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• pp.80-99
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• 2016

Objectives : Instrumental chemical analysis was utilized to investigate the effect of Add-Omit-Saenghyeoryunbu-eum(AO-SHU) on diabetic treatment. One of the most exciting, yet also controversial, arguments is the safety and biological mechanisms of the natural medicine on human body. Therefore, the aim of this study is to provide a better understanding on bioactive chemical components, hazards of heavy metal contamination and biological mechanism of the diabetic medicine composed of 12 different natural herbs. Methods : To study bioactive compound and metallic component in the diabetic medicine in detail, LC-MS/MS (Liquid Chromatography-Mass/Mass), GC (Gas Chromatography) and ICP (Inductively Coupled Plasma) were utilized to characterize the extract of the diabetic medicine and the result was compared with 18 marker substances selected from literature survey. In addition, in vitro assay experiments including GPR 119 activity and human DGAT-1 inhibition, and OGTT (Oral Glucose Tolerance Test) were performed to verify the effectiveness of this medicine on diabetic treatment. Results : Out of 18 marker substances, 9 bioactive compounds were identified from LC-MS/MS analysis which include Citruline, Catalpol, Berberine, Ginsenoside Rb1, Ginsenoside Rg1, Oleanolic acid, β-Sitosterol, Mangiferin, and Schizandrin. ICP study on 245 residual pesticides revealed that 239 species were not detected but 6 species, Dimethomorph, Trifloxystrobin, Pyraclostrobin, Isoprocarb, Carbaryl and Flubendiamide, while the amounts are trace levels, below permitted concentrations. The biological activity was observed in vitro assay and Oral Glucose Tolerance Test(OGTT), which are consistent with a preliminary clinical test result, a drop in blood sugar level after taking this herbal medicine. Conclusions : Instrumental chemical analysis using LC-MS/MS, GC, and ICP was conducted successfully to identify bioactive compounds in AO-SHU for the treatment of diabetes, finding 9 bioactive compounds. Furthermore, in vitro assay experiments and OGTT show that AO-SHU has its biological activities, which imply that it can be a candidate for the future diabetes remedy.