Cross-sections of Myristica malabarica (Lam) seed and mouse brain tissue were imprinted on such ordinary surfaces as printer paper and TLC plates, and successfully imaged by desorption electrospray ionization mass spectrometry (DESI-MS) at 250 μm resolution. Chemical images representing the distribution of the alkaloid malabaricone C in the seed substructures and individual lipids in the substructures of the brain were obtained. Practical implications include analysis of irregular or soft materials, easy recording, transportation and storage of the latent image, and posterior analysis of the samples by different techniques without the requirement of addition of matrices or use of specific types of surfaces. © The Royal Society of Chemistry 2011.

Pradeep Thalappil

Department Of Chemistry

Amitava Srimany

Hemanta R. Naik

CHEMICAL IMAGES

DESORPTION ELECTROSPRAY IONIZATION MASS SPECTROMETRIES

LATENT IMAGES

MOUSE BRAIN

POSTERIOR ANALYSIS

Soft Material

Desorption

Image recording

ionization

Mammals

Mass spectrometry

Materials handling

Tissue

Electrospray ionization

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Analytical Methods

Areca nut (seed of Areca catechu) is consumed by people from different parts of Asia, including India. The four major alkaloids present in areca nut are arecoline, arecaidine, guvacoline and guvacine. Upon cutting, the nut reveals two kinds of regions; white and brown. In our present study, we have monitored the formation of these two regions within the nut during maturation, using the non-invasive techniques of magnetic resonance imaging (MRI) and volume localized magnetic resonance spectroscopy (MRS). Electrospray ionization mass spectrometry (ESI MS) and desorption electrospray ionization mass spectrometry (DESI MS) imaging have been used to study the associated change in the alkaloid contents of these two regions during the growth of the nut. Our study reveals that white and brown regions start forming within the nut when the liquid within starts solidifying. At the final stage of maturity, arecoline, arecaidine and guvacoline get segregated in the brown region whereas guvacine gets to the white region of the nut. The transport of molecules with maturity and corresponding pattern formation are expected to be associated with a multitude of physiochemical changes. © 2016 Elsevier Ltd. All rights reserved.

Phytochemistry

Developmental patterning and segregation of alkaloids in areca nut (seed of Areca catechu) revealed by magnetic resonance and mass spectrometry imaging

DESI MS, has been successfully employed for the analysis of molecules from a wide variety of surfaces without prior sample treatment. The efficiency of DESI MS relies on various parameters. However, those that critically affect the ionization of biological samples include: the solvent system and the sample or sample spotting surfaces. These parameters gain unequivocal dominance specially whilst dealing with sensitive and intricate biological samples. This review is meant to capture the attention of the DESI-MS researchers towards the crucial role of the solvent and sample spotting surfaces for successful biological DESI-MS. This review highlights these parameters as the backbone of the breakthroughs achieved in the analysis of biological materials of plant, bacterial, animal and human origins. © 2016 Elsevier B.V..

TrAC - Trends in Analytical Chemistry

Biological Desorption Electrospray Ionization Mass Spectrometry (DESI MS) - unequivocal role of crucial ionization factors, solvent system and substrates

Rohitukine, a chromone alkaloid, possesses anti-inflammatory, anti-cancer and immuno-modulatory properties. It has been reported from four species, belonging to the families, Meliaceae and Rubiaceae. Stem bark of Dysoxylum binectariferum (Meliaceae) accumulates the highest amount of rohitukine (3-7% by dry weight). In this study, we examine the spatial and temporal distribution of rohitukine and related compounds during various stages of seed development in D. binectariferum using desorption electrospray ionization mass spectrometry imaging (DESI MSI). Rohitukine (m/z 306.2) accumulation increased from early seed development to seed maturity stage. The spatial distribution of rohitukine was largely restricted to the cotyledonary tissue followed by the embryo and least in the seed coat. Besides rohitukine, rohitukine acetate (m/z 348.2) and glycosylated rohitukine (m/z 468.2) were also detected, both through mass fragmentation and exact mass analysis through Orbitrap mass spectrometry. These results indicate a dynamic pattern of chromane alkaloid accumulation through seed development in D. binectariferum. © 2015 Elsevier Ltd. All rights reserved.

Ambient ionization mass spectrometry imaging of Rohitukine, a chromone anti-cancer alkaloid, during seed development in Dysoxylum binectariferum Hook.f (Meliaceae)

Rationale Various disease conditions, particularly tumours, can be understood easily by studying changes in the lipid profile of cells. While lipid profiles of tissues have been recorded by desorption electrospray ionization mass spectrometric (DESI-MS) imaging, there is paucity in standardized protocols for sample preparation involving cell cultures to generate reliable results. In this study, we report a method for the direct analysis of lipids from cultured cells by incorporating them onto Whatman 42 filter paper as a substrate for reliable DESI-MS analysis. Methods The WERI-RB1 cell line was spotted on commonly used substrates for DESI-MS analysis, such as glass slides, Teflon coated glass slides, thin layer chromatography (TLC) plates, and Whatman 42 filter paper. A comparison of mass spectrometric images with two different lipids was made to understand the behaviour of different surfaces when the same sample was spotted on them. Relative intensities of different lipid peaks in the WERI-RB1 cell line were compared and relative lipid abundances were also compared across two different human retinoblastoma cell lines; WERI-RB1 and Y79. Results The study demonstrates that good lipid signals can be obtained by DESI-MS when the cells are spotted on Whatman 42 filter paper. Tandem mass spectrometry was performed to identify the lipids as glycerophosphocholines (PC). Better lipid images from assembly of cells were obtained with distinct boundary when they were spotted on Whatman 42 filter paper than other surfaces. Conclusions We demonstrate the use of a simple substrate for reliable DESI-MS analysis of cultured cells. This method has the potential to understand various interactions of cells with other external agents. The current method would help in the application of DESI-MS for biology in general and medical sciences in particular. Copyright © 2015 John Wiley & Sons, Ltd.

Rapid Communications in Mass Spectrometry

Identification of effective substrates for the direct analysis of lipids from cell lines using desorption electrospray ionization mass spectrometry

Basil (Ocimum sp.), a medicinal herb is used fresh and/or dry in various (culinary, cosmetic and pharmaceutical) preparations. Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. basilici is limiting basil cultivation in many countries. Since the leaf is the edible part in basil, new approaches are required to identify, and to prevent the spread of Fusarium pathogens. Desorption electrospray ionization mass spectrometry (DESI MS) was used for imaging thin layer chromatography (TLC) - imprints of leaves of three different species of basil (Ocimum basilicum L., O. tenuiflorum L., and O. gratissimum L.), and the molecular manifestations during Fusarium contamination are recorded. DESI MS images showed the chemotaxonomic differences of basil species and the changes in metabolite ion peaks during pathogen infection. Besides easy detection of reported toxic metabolite(s) of the pathogen(s), the results include molecular images showing spatial distribution of all coexisting surface-bound metabolites in plant leaves, their fragment ions, and the transient changes in their spatial distribution during Fusarium attack under natural conditions. Demonstration of the same protocol to image seedling, young/mature leaves, basil/other related plant (Patchouli - Pogostemon cablin (Blanco) Benth.), wilt/other disease symptoms shows that prior knowledge of the metabolite profile of the plant/pathogen is not required. This rapid detection method can be tailored to large scale screening programs for plant diseases suggesting potential implications in agriculture and quarantine requirements. © The Royal Society of Chemistry.

RSC Advances

Rapid detection of Fusarium wilt in basil (Ocimum sp.) leaves by desorption electrospray ionization mass spectrometry (DESI MS) imaging

Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids

Desorption electrospray ionization mass spectrometry for lipid characterization and biological tissue imaging

Analytical Chemistry

Direct Plant Tissue Analysis and Imprint Imaging by Desorption Electrospray Ionization Mass Spectrometry

Analysis of Secondary Plant Metabolites by Indirect Desorption Electrospray Ionization Imaging Mass Spectrometry

Journal of Neurochemistry

New approach for glyco- and lipidomics - Molecular scanning of human brain gangliosides by TLC-Blot and MALDI-QIT-TOF MS

Chem. Commun.

Perspectives in imaging using mass spectrometry

Tissue imprint imaging by desorption electrospray ionization mass spectrometry

Journal	Analytical Methods
ISSN	17599660
Open Access	No