Differential Rapid Screening of Phytochemicals by Leaf Spray Mass Spectrometry

Muller, Thomas,Cooks, R. Graham Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.3

Ambient ionization can be achieved by generating an electrospray directly from plant tissue ("leaf spray"). The resulting mass spectra are characteristic of ionizable phytochemicals in the plant material. By subtracting the leaf spray spectra recorded from the petals of two hibiscus species H. moscheutos and H. syriacus one gains rapid access to the metabolites that differ most in the two petals. One such compound was identified as the sambubioside of quercitin (or delphinidin) while others are known flavones. Major interest centered on a $C_{19}H_{29}NO_5$ compound that occurs only in the large H. moscheutos bloom. Attempts were made to characterize this compound by mass spectrometry alone as a test of such an approach. This showed that the compound is an alkaloid, assigned to the polyhydroxylated pyrrolidine class, and bound via a $C_3$ hydrocarbon unit to a monoterpene.

Differential Rapid Screening of Phytochemicals by Leaf Spray Mass Spectrometry

Thomas Müller,R. Graham Cooks 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.3

Ambient ionization can be achieved by generating an electrospray directly from plant tissue (“leaf spray”). The resulting mass spectra are characteristic of ionizable phytochemicals in the plant material. By subtracting the leaf spray spectra recorded from the petals of two hibiscus species H. moscheutos and H. syriacus one gains rapid access to the metabolites that differ most in the two petals. One such compound was identified as the sambubioside of quercitin (or delphinidin) while others are known flavones. Major interest centered on a C19H29NO5 compound that occurs only in the large H. moscheutos bloom. Attempts were made to characterize this compound by mass spectrometry alone as a test of such an approach. This showed that the compound is an alkaloid, assigned to the polyhydroxylated pyrrolidine class, and bound via a C3 hydrocarbon unit to a monoterpene.

Hyperthermal Collision-induced Dissociation of Bromotoluene Radical Cations at Self-Assembled Monolayer Surfaces

Jo, Sung-Chan,Augusti, Rodinei,Cooks, R. Graham Korean Society for Mass Spectrometry 2011 Mass spectrometry letters Vol.2 No.1

Hyperthermal ion/surface collisions of bromotoluene radical cations were studied using perfluorinated (F-SAM) and hydroxyl-terminated (OH-SAM) self-assembled monolayer surfaces in a tandem mass spectrometer with BEEQ geometry. The isomers were differentiated by ion abundance ratios taken from surface-induced dissociation (SID). The dissociation rate followed the order of ortho > meta > para isomers. The peak abundance ratio of m/z 51 to m/z 65 showed the best result to discern the isomers. A dissociation channel leading to tolylium ion was suggested to be responsible for the pronounced isomeric differences. The capability of SID to provide high-energy activation with narrow internal energy distribution may have channeled the reaction into the specific dissociation pathway, also facilitating small differences in reaction rates to be effective in the spectral time window of this experiment. All of the molecular ions experiencing reactive collisions with the F-SAM surface undergo transhalogenation, in which a fluorine atom on the surface replaces the bromine in the incoming ions. This reactive collision was dependent on the laboratory collision energy occurring in ca. 40.75 eV range.

Hyperthermal Collision-induced Dissociation of Bromotoluene Radical Cations at Self-Assembled Monolayer Surfaces

( Sung-chan Jo ),( Rodinei Augusti ),( R. Graham Cooks ) 한국질량분석학회 2011 Mass spectrometry letters Vol.2 No.1

Hyperthermal ion/surface collisions of bromotoluene radical cations were studied using perfluorinated (F-SAM) and hydroxyl-terminated (OH-SAM) self-assembled monolayer surfaces in a tandem mass spectrometer with BEEQ geometry. The isomers were differentiated by ion abundance ratios taken from surface-induced dissociation (SID). The dissociation rate followed the order of ortho > meta > para isomers. The peak abundance ratio of m/z 51 to m/z 65 showed the best result to discern the isomers. A dissociation channel leading to tolylium ion was suggested to be responsible for the pronounced isomeric differences. The capability of SID to provide high-energy activation with narrow internal energy distribution may have channeled the reaction into the specific dissociation pathway, also facilitating small differences in reaction rates to be effective in the spectral time window of this experiment. All of the molecular ions experiencing reactive collisions with the F-SAM surface undergo transhalogenation, in which a fluorine atom on the surface replaces the bromine in the incoming ions. This reactive collision was dependent on the laboratory collision energy occurring in ca. 40.75 eV range.

Hyperthermal Collisions of Bromotoluene Molecular Cations at Self-Assembled Monolayer Surfaces

Sung-Chan Jo,Rodinei Augusti,R. Graham Cooks 사단법인 한국질량분석학회 2011 Mass spectrometry letters Vol.2 No.1

Hyperthermal ion/surface collisions of bromotoluene molecular ions were studied using perfluorinated (F-SAM) andhydroxyl-terminated (OH-SAM) self-assembled monolayer surfaces in a tandem mass spectrometer with BEEQ geometry. Theisomers were differentiated by ion abundance ratios taken from surface-induced dissociation (SID). The dissociation rate followedthe order of ortho>meta>para isomers. The peak abundance ratio of m/z 51 to m/z 65 showed the best result to discern theisomers, while the other ratios would effectively serve the same purpose as well. A dissociation channel leading to tolylium ionwas suggested to be responsible for the pronounced isomeric differentiability. The capability of SID to provide high-energy activationwith narrow internal energy distribution may have channeled the reaction into the specific dissociation pathway, also facilitatingsmall difference in reaction rates to be effective in the spectral time window of this experiment. All the molecular ions experiencedreactive collisions with the F-SAM surface leading to transhalogenation products, where a fluorine atom from the surface replacesthe bromine of the projectile. This reactive collision was dependant on the laboratory collision energy occurring in ca. 40~75 eV range.

Low-Energy Ionic Collisions at Molecular Solids

Cyriac, Jobin,Pradeep, T.,Kang, H.,Souda, R.,Cooks, R. G. American Chemical Society 2012 Chemical reviews Vol.112 No.10

<P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/chreay/2012/chreay.2012.112.issue-10/cr200384k/production/images/medium/cr-2011-00384k_0048.gif'></P>

A photophysical study of PCBM thin films

Cook, S.,Ohkita, H.,Kim, Y.,Benson-Smith, J.J.,Bradley, D.D.C.,Durrant, J.R. North Holland ; Elsevier Science Ltd 2007 Chemical physics letters Vol.445 No.4

Jablonski diagram comparing the energy of the intramolecular and the more delocalised charge transfer states in thin films of PCBM.

國民學校에 있어서의 英語敎育

崔國善 誠信女子大學校 1968 硏究論文集 Vol.1 No.-

海洋學的 要素의 年週變化가 海洋生物에 미치는 影響 : 莞島 海域의 海苔에 關하여 on the laver in the Wan-Do coast area

曺炷煥,朱國英 조선대학교 기초과학연구소 1984 自然科學硏究 Vol.7 No.1

This paper aims to contribute to the increase of laver production with the scientific raising and management of laver, after axamining closely the various surroundings of the inside ocean and the outside of Wan-Do, the central farming place of laver, physically and chemically and comparing and investigating the laver productivity of it. As a result of investigating and studying many important factors thrice a year, that is, in the months of September, Movember an February from 1981, I measured the following factors : water temperature, salinity, dissolved oxygen, pH, Nitrite-N. Phosphate-P, and transparency. The results of study are as follows. The change of water temperature in February 1982 Varied from 5.0℃ to 8.5℃ and in February 1983 Varied from 6.5℃ to 8.5℃. The Salinity in February 1982 fluctuated with in the range between 33.41‰ and 34.03‰ and in February 1983. fluctuation with in the range between 33.31‰ and 33.60‰. pH in general showed a fluctuation between 7.89 and 8.1. The range of dissolved oxygen in 1981 was from 4.40㎖/ℓ to 7.22㎖/ℓ and in 1982, was from 4.20㎖/ℓ to 6.50㎖/ℓ. The change of dissolved oxygen showed the maximum of 1.22㎖/ℓ in February 1981 at station 3, and a minimum 4.20㎖/ℓ at statimon 3 in Septemer 1982. Transparency showed a fluctuation between 0.25m and 1.5m. The change of Nitrite-N in 1982 or 1983, Varied from 1.19㎍-at/ℓ to 0.66㎍-at/ℓ. The phosphate-P in 1982 or 1983 fluctuated with in the range between 0.35㎍-at/ℓ and 1.08㎍-at/ℓ. As a result of the study of the annual variation on oceanographical factors of Wan-Do coast area. Water temperature, more than anything else, was showed up as having an important effects to the laver growth condition and the situation of laver production of the outside ocean was showed up better than that of the inside ocean. I believe the cause of this is that the situation of seawater exchange of inside ocean is poor. And as a result of the overconcentration of laver is also poor. I think the quantity of laver temperature etc., the production of laver is also landwater is little, the exchange of seawater is good, and the quantity of dissoled oxygen is abundant.

과학의 수준별 학습을 위한 Web 기반 수업 자료의 개발

조주환,주국영 조선대학교 사범대학 부설 교과교육연구소 2001 敎科敎育硏究 Vol.4 No.1

본 연구는 과학의 수준별 교육과정 편성·운영을 효율적으로 수행하기 위해서 학생 능력과 개인차에 따른 다양한 교육의 기회를 제공하고, 자기주도적으로 학습능력을 신장시킬 수 있도록 컴퓨터를 이용하여 학습자의 학습 능력과 수준에 맞는 다양한 컴퓨터용 웹 자료들을 개발하는 데 있다. 본 연구에서 제작한 Web 기반 학습자료(WBI)는 학습자가 스스로 본시 학습에 필요한 선수학습요소를 파악하고 부족한 부분을 보충할 수 있으므로 본시 수업시 학습자의 학습 동기를 촉진시킬 것으로 기대한다. 또한 보충 학습 자료는 본시 학습 내용을 보다 상세하게 안내해 줌으로써 결손 학습 부분을 원활하게 보충해 줌으로써 학업 성취를 높일수 있을 것으로 기대한다. 따라서 제작한 Web기반 심화·보충형 수업 자료는 학습자들이 언제 어디서나 자기의 수준에 맞추어 자기 주도적으로 흥미 있게 학습할 수 있는 기초자료가 될 수 있다고 본다. 그리고 2002년부터 적용되는 수준별 교육과정인 7차 고등학교 과학과 교육과정을 수행하는데 있어서도 도움을 줄 수 있는 기초자료가 될 수 있다고 본다. 따라서 많은 웹 자료들이 개발된다면 현장의 교사들이 일선에서 활용하기에 용이하리라 생각한다. The purposes of this study are to provide students with opportunities according to their different learning abilities and levels in order to implement effectively the differentiated curriculum of science, and to develop various web data for them to improve their learning abilities for themselves. The WBI of this study is expected to stimulate the learners' motivation in class since it helps them to understand the basic knowledge and supplement the weak points. The complementary data for learning are expected to enhance learners' attainment as they show the learning tasks in detail and supplement the missed points successfully. So the advanced/complementary data for learning will be basic data that help students to learn positively given subject everywhere and everytime, and that give a aid to implement the 7th differentiate curriculum of science that will be applied in 2002. Therefore if we develop various web data, teachers will be able to apply them easily in their classrooms.