• Journal of the Korean Wood Science and Technology
• /
• v.51 no.3
• /
• pp.157-172
• /
• 2023

Azadirachta excelsa, is a plant belonging to the same genus as Indian neem (Azadirachta indica), and its use as a pesticide is reported by few studies. Despite being a different species, it is expected to have the same biopesticide potential as A. indica. Therefore, this study aims to investigate the anti-termite activity of n-hexane and methanol extracts of A. excelsa seed kernel at various concentrations against Coptotermes curvignathus. The methanol extract demonstrated greater termicidal activity than n-hexane at doses test of 2%, 4%, and 8%. It also showed 100% termite mortality on the third day of administering the 8% dose. According to the gas chromatography with mass spectrometry data, the putative main components of the n-hexane extract were hexadecanoic acid, ethyl ester (18.99%), 9,12-octadecadienoic acid (Z,Z)- (16.31%), and 9-octadecenal (16.23%). In contrast, the principal constituents of methanol extract were patchouli alcohol (28.1%), delta-guaiene (15.15%), and alpha-guaiene (11.93%). Furthermore, limonoids profiling of A. excelsa methanol extract was determined using Ultrahigh-performance liquid chromatography coupled with quadrupole-Orbitrap high-resolution mass spectrometry. The number of limonoids identified tentatively was fifteen, such as 6-deacetylnimbin, nimbolidin C, nimbolide, 6-acetylnimbandiol, 6-deacetyl-nimbinene, salannol, 28-deoxonimbolide, gedunin, nimbandiol, epoxyazadiradione, azadirone, 2',3'-dihydrosalannin, marrangin, nimbocinol, and azadirachtin. They were the same as those reported in the seed and leaves of A. indica, but its largest component in A. excelsa was 6-deacetylnimbin. As a result, the presence of these compounds may be responsible for the anti-termite activity of A. excelsa seed kernel extract. Additionally, column chromatography of methanol extract yielded 6-deacetylnimbin, which was found to be antifeedant and termiticide against C. curvignathus.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.27 no.3
• /
• pp.144-157
• /
• 2022

Noble gases, which are chemically inert and behave conservatively in marine environments, have been used as tracers of physical processes such as air-sea gas exchange, mixing of water masses, and distribution of glacial meltwater in the ocean. For precise measurements of Ne, Ar, and Kr, we developed a mass spectrometric system consisting of a quadrupole mass spectrometer (QMS), a high vacuum preparation line, an activated charcoal cryogenic trap (ACC), and a set of isotope standard gases. The high vacuum line consists of three sections: (1) a sample extraction section that extracts the dissolved gases in the sample and mixes them with the standard gases, (2) a gas preparation section that removes reactive gases using getters and separates the noble gases according to their evaporation points with the ACC, and (3) a gas analysis section that measures concentrations of each noble gas. The ACC attached to the gas preparation section markedly lowered the partial pressures of Ar and CO₂ in the QMS, which resulted in a reduced uncertainty of Ne isotope analysis. The isotope standard gases were prepared by mixing ²²Ne, ³⁶Ar, and ⁸⁶Kr. The amounts of each element in the mixed standard gases were determined by the reverse isotope dilution method with repeated measurements of the atmosphere. The analytical system achieved precisions for Ne, Ar, and Kr concentrations of 0.7%, 0.7%, and 0.4%, respectively. The accuracies confirmed by the analyses of air-equilibrated water were 0.5%, 1.0%, and 1.7% for Ne, Ar, and Kr, respectively.

• Korean Journal of Medicinal Crop Science
• /
• v.28 no.1
• /
• pp.21-28
• /
• 2020

Background: Owing to its high efficiency in lipid and protein production, peanut (Arachis hypogaea L.) is considered one of most important crops world-wide. The kernels of peanuts are undoubtedly the most important product this plant, whereas the skin is almost completely neglected in nutraceutical terms. However, peanut skin contains potentially health-promoting phenolics and dietary fiber, and there is considerable potential for commercial exploitation. In this study, we evaluated the α-glucosidase inhibitory activity of an extract of peanut skin (PS). Methods and Results: The α-glucosidase inhibitory effects of 80% ethanol extracts of peanut (A. hypogaea L. 'Sinpalkwang') skin were evaluated and found to have a half-maximal inhibitory concentration (IC₅₀) value of 1.2 ㎍/㎖. Progress curves for enzyme reactions were recorded spectrophotometrically, and the inhibition kinetics revealed time-dependent inhibition with enzyme isomerization. Furthermore, using ultra-high performance liquid chromatography combined with quadrupole-orbitrap mass spectrometry, we identified 26 compounds in the peanut skin extract, namely, catechin, epicatechin, and 24 proanthocyanidins. Conclusions: The results suggest that peanut skin can be utilized as an effective source of α-glucosidase inhibition in functional foods and nutraceuticals.

• Molecules and Cells
• /
• v.37 no.2
• /
• pp.172-177
• /
• 2014

A glycosyltransferase, YjiC, from Bacillus licheniformis has been used for the modification of the commercially available isoflavonoids genistein, daidzein, biochanin A and formononetin. The in vitro glycosylation reaction, using UDP-${\alpha}$-D-glucose as a donor for the glucose moiety and aforementioned four acceptor molecules, showed the prominent glycosylation at 4' and 7 hydroxyl groups, but not at the $5^{th}$ hydroxyl group of the A-ring, resulting in the production of genistein 4'-O-${\beta}$-D-glucoside, genistein 7-O-${\beta}$-D-glucoside (genistin), genistein 4',7-O-${\beta}$-D-diglucoside, biochanin A-7-O-${\beta}$-D-glucoside (sissotrin), daidzein 4'-O-${\beta}$-D-glucoside, daidzein 7-O-${\beta}$-D-glucoside (daidzin), daidzein 4', 7-O-${\beta}$-D-diglucoside, and formononetin 7-O-${\beta}$-D-glucoside (ononin). The structures of all the products were elucidated using high performance liquid chromatography-photo diode array and high resolution quadrupole time-of-flight electrospray ionization mass spectrometry (HR QTOF-ESI/MS) analysis, and were compared with commercially available standard compounds. Significantly higher bioconversion rates of all four isoflavonoids was observed in both in vitro as well as in vivo bioconversion reactions. The in vivo fermentation of the isoflavonoids by applying engineered E. coli $BL21(DE3)/{\Delta}pgi{\Delta}zwf{\Delta}ushA$ overexpressing phosphoglucomutase (pgm) and glucose 1-phosphate uridyltransferase (galU), along with YjiC, found more than 60% average conversion of $200{\mu}M$ of supplemented isoflavonoids, without any additional UDP-${\alpha}$-D-glucose added in fermentation medium, which could be very beneficial to large scale industrial production of isoflavonoid glucosides.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1999.07a
• /
• pp.249-249
• /
• 1999

GaN과 같은 III-nitride 반도체 관한 식각 기술의 연구는 blue-emitting laser diode(LD)를 위한 경면(mirror facet)의 형성뿐만아니라 새로운 display 용도의 light emitting diodes (LED), 고온에서 작동되는 광전소자 제조 등에도 그 중요성이 증대되고 있다. 최근에는 III-nitride 물질의 높은 식각속도와 미려하고 수직한 식각형상을 이루기 위하여 ECR(Electron Cyclotron Resonance)이나 ICP(Inductively Coupled Plasma)와 같은 고밀도 플라즈마 식각과 CAIBE(Chemically assisted ion beam etching)를 이용한 연구가 진행되고 있다. 현재 제조되어 지고 있는 LED 및 LD와 같은 광소자의 구조의 대부분은 p-GaN/AlGaN/InGaN(Q.W)/AlGaN/n-GaN 와 같은 여러 층의 형태로 이루어져 있다. 이중 InGaN는 광소자나 전자소자의 특성에 영향을 주는 가장 중요한 부분으로써 현재까지 보고된 식각연구는 undoped GaN에 대부분 집중되고 있고 이에 비해 소자 특성에 핵심을 이루는 InGaN의 식각특성에 관한 연구는 미흡한 상황이다. 본 연구에서는 고밀도 플라즈마원인 ICP 장비를 이용하여 InGaN를 식각하였고, 식각에는 Cl2/CH4, Cl2/Ar 플라즈마를 사용하였다. InGaN의 식각특성에 영향을 미치는 플라즈마의 특성을 관찰하기 위하여 quadrupole mass spectrometry(QMS)와 optical emission spectroscopy(PES)를 사용하였다. 기판 온도는 5$0^{\circ}C$, 공정 압력은 5,Torr에서 30mTorr로 변화시켰고 inductive power는 200~800watt, bias voltage는 0~-200voltage로 변화시켰으며 식각마스크로는 SiO2를 patterning 하여 사용하였다. n-GaN, p-GaN 층 이외에 광소자 제조시 필수적인 InGaN 층을 100% Cl2로 식각한 경우에 InGaN의 식각속도가 GaN에 비해 매우 낮은 식각속도를 보였다. Cl2 gas에 소량의 CH4나 Ar gas를 첨가하는 경우와 공정압력을 감소시키는 경우 식각속도는 증가하였고, Cl2/10%Ar 플라즈마에서 공정 압력을 감소시키는 경우 식각속도는 증가하였고, Cl2/10%CHF3 와 Cl2/10%Ar 플라즈마에서 공정압력을 15mTorr로 감소시키는 경우 InGaN과 GaNrks의 선택적인 식각이 가능하였다. InGaN의 식각속도는 Cl2/Ar 플라즈마의 이온에 의한 Cl2/CHF3(CH4) 플라즈마에서의 CHx radical 형성에 의하여 증가하는 것으로 사료되어 진다.

• Journal of Ginseng Research
• /
• v.40 no.4
• /
• pp.344-350
• /
• 2016

Background: Mountain-cultivated ginseng (MCG) and cultivated ginseng (CG) both belong to Panax ginseng and have similar ingredients. However, their pharmacological activities are different due to their significantly different growth environments. Methods: An ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS)-based approach was developed to distinguish MCG and CG. Multivariate statistical methods, such as principal component analysis and supervised orthogonal partial-least-squares discrimination analysis were used to select the influential components. Results: Under optimized UPLC-QTOF-MS/MS conditions, 40 ginsenosides in both MCG and CG were unambiguously identified and tentatively assigned. The results showed that the characteristic components of CG and MCG included ginsenoside Ra3/isomer, gypenoside XVII, quinquenoside R1, ginsenoside Ra7, notoginsenoside Fe, ginsenoside Ra2, ginsenoside Rs6/Rs7, malonyl ginsenoside Rc, malonyl ginsenoside Rb1, malonyl ginsenoside Rb2, palmitoleic acid, and ethyl linoleate. The malony ginsenosides are abundant in CG, but higher levels of the minor ginsenosides were detected in MCG. Conclusion: This is the first time that the differences between CG and MCG have been observed systematically at the chemical level. Our results suggested that using the identified characteristic components as chemical markers to identify different ginseng products is effective and viable.

• Journal of Ginseng Research
• /
• v.44 no.4
• /
• pp.552-562
• /
• 2020

Background: Ginsenosides are the unique and bioactive components in ginseng. Ginsenosides are affected by the growing environment and conditions. In New Zealand (NZ), Panax ginseng Meyer (P. ginseng) is grown as a secondary crop under a pine tree canopy with an open-field forest environment. There is no thorough analysis reported about NZ-grown ginseng. Methods: Ginsenosides from NZ-grown P. ginseng in different parts (main root, fine root, rhizome, stem, and leaf) with different ages (6, 12, 13, and 14 years) were extracted by ultrasonic extraction and characterized by Liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry. Twenty-one ginsenosides in these samples were accurately quantified and relatively quantified with 13 ginsenoside standards. Results: All compounds were separated in 40 min, and a total of 102 ginsenosides were identified by matching MS spectra data with 23 standard references or published known ginsenosides from P. ginseng. The quantitative results showed that the total content of ginsenosides in various parts of P. ginseng varied, which was not obviously dependent on age. In the underground parts, the 13-year-old ginseng root contained more abundant ginsenosides among tested ginseng samples, whereas in the aboveground parts, the greatest amount of ginsenosides was from the 14-year-old sample. In addition, the amount of ginsenosides is higher in the leaf and fine root and much lower in the stem than in the other parts of P. ginseng. Conclusion: This study provides the first-ever comprehensive report on NZ-grown wild simulated P. ginseng.

• Journal of Ginseng Research
• /
• v.42 no.3
• /
• pp.277-287
• /
• 2018

Background: Temperature is an essential condition in red ginseng processing. The pharmacological activities of red ginseng under different steam temperatures are significantly different. Methods: In this study, an ultrahigh-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry was developed to distinguish the red ginseng products that were steamed at high and low temperatures. Multivariate statistical analyses such as principal component analysis and supervised orthogonal partial least squared discrimination analysis were used to determine the influential components of the different samples. Results: The results showed that different steamed red ginseng samples can be identified, and the characteristic components were 20-gluco-ginsenoside Rf, ginsenoside Re, ginsenoside Rg1, and malonyl-ginsenoside Rb1 in red ginseng steamed at low temperature. Meanwhile, the characteristic components in red ginseng steamed at high temperature were 20R-ginsenoside Rs3 and ginsenoside Rs4. Polar ginsenosides were abundant in red ginseng steamed at low temperature, whereas higher levels of less polar ginsenosides were detected in red ginseng steamed at high temperature. Conclusion: This study makes the first time that differences between red ginseng steamed under different temperatures and their ginsenosides transformation have been observed systematically at the chemistry level. The results suggested that the identified chemical markers can be used to illustrate the transformation of ginsenosides in red ginseng processing.

• Journal of Ginseng Research
• /
• v.44 no.5
• /
• pp.680-689
• /
• 2020

Background: Peptides have diverse and important physiological roles in plants and are ideal markers for species identification. It is unclear whether there are specific peptides in Panax quinquefolius L. (PQ). The aims of this study were to identify Quinetides, a series of diverse posttranslational modified native peptides of the ribonuclease-like storage protein (ginseng major protein), from PQ to explore novel peptide markers and develop a new method to distinguish PQ from Panax ginseng. Methods: We used different fragmentation modes in the LTQ Orbitrap analysis to identify the enriched Quinetide targets of PQ, and we discovered Quinetide markers of PQ and P. ginseng using ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry analysis. These "peptide markers" were validated by simultaneously monitoring Rf and F11 as standard ginsenosides. Results: We discovered 100 Quinetides of PQ with various post-translational modifications (PTMs), including a series of glycopeptides, all of which originated from the protein ginseng major protein. We effectively distinguished PQ from P. ginseng using new "peptide markers." Four unique peptides (Quinetides TP6 and TP7 as markers of PQ and Quinetides TP8 and TP9 as markers of P. ginseng) and their associated glycosylation products were discovered in PQ and P. ginseng. Conclusion: We provide specific information on PQ peptides and propose the clinical application of peptide markers to distinguish PQ from P. ginseng.

• Journal of Ginseng Research
• /
• v.41 no.3
• /
• pp.379-385
• /
• 2017

In this study, white ginseng was used as the raw material, which was fermented with Paecilomyces hepiali through solid culture medium, to produce ginsenosides with modified chemical composition. The characteristic chemical markers of the products thus produced were investigated using rapid resolution liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (RRLC-QTOF-MS). Chemical profiling data were obtained, which were then subjected to multivariate statistical analysis for the systematic comparison of active ingredients in white ginseng and fermented ginseng to understand the beneficial properties of ginsenoside metabolites. In addition, the effects of these components on biological activity were investigated to understand the improvements in the phagocytic function of macrophages in zebrafish. According to the established RRLC-QTOF-MS chemical profiling, the contents in ginsenosides of high molecular weight, especially malonylated protopanaxadiol ginsenosides, were slightly reduced due to the fermentation, which were hydrolyzed into rare and minor ginsenosides. Moreover, the facilitation of macrophage phagocytic function in zebrafish following treatment with different ginseng extracts confirmed that the fermented ginseng is superior to white ginseng. Our results prove that there is a profound change in chemical constituents of ginsenosides during the fermentation process, which has a significant effect on the biological activity of these compounds.