Related Experiment Video
Updated: Apr 17, 2026

Sequencing of Plant Wall Heteroxylans Using Enzymic, Chemical Methylation and Physical Mass Spectrometry, Nuclear Magnetic Resonance Techniques
Published on: March 24, 2016
Molecular characterization of ongoing enzymatic reactions in raw garlic cloves using extractive electrospray
Hua Zhang1, Konstantin Chingin, Liang Zhu
1Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, East China Institute of Technology , Nanchang 330013 P.R. China.
Abstract:
Characterization of enzymatic reactions occurring in untreated biological samples is of increasing interest. Herein, the chemical conversion of alliin to allicin, catalyzed by allinase, in raw garlic cloves has been followed in vivo by internal extractive electrospray ionization mass spectrometry (iEESI-MS). Both precursors and products of the enzymatic reaction were instantaneously extracted by infused solution running throughout the tissue and directly electrospray ionized on the edge of the bulk sample for online MS analysis. Compared to the room-temperature (+25 °C) scenario, the alliin conversion in garlic cloves decreased by (7.2 ± 1.4) times upon heating to +80 °C and by (5.9 ± 0.8) times upon cooling to -16 °C. Exposure of garlic to gentle ultrasound irradiation for 3 h accelerated the reaction by (1.2 ± 0.1) times. A 10 s microwave irradiation promoted alliin conversion by (1.6 ± 0.4) times, but longer exposure to microwave irradiation (90 s) slowed the reaction by (28.5 ± 7.5) times compared to the reference analysis. This method has been further employed to monitor the germination process of garlic. These data revealed that over a 2 day garlic sprouting, the allicin/alliin ratio increased by (2.2 ± 0.5) times, and the averaged degree of polymerization for the detected oligosaccharides/polysaccharides decreased from 11.6 to 9.4. Overall, these findings suggest the potential use of iEESI-MS for in vivo studies of enzymatic reactions in native biological matrices.
More Related Videos
17:12Profiling of Methyltransferases and Other S-adenosyl-L-homocysteine-binding Proteins by Capture Compound Mass Spectrometry CCMS
Published on: December 20, 2010
09:38Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures
Published on: January 7, 2019
Related Concept Videos
Mass Spectrometry: Complex Analysis
GC–MS is a powerful hyphenated method commonly used in forensics and environmental...
Electrospray Ionization (ESI) Mass Spectrometry
ESI utilizes electrical energy to transfer ions from the liquid phase of the sample into the...
Mass Spectrometry: Overview
Gas Chromatography–Mass Spectrometry (GC–MS)
A gas chromatograph consists of a long, narrow capillary column with a polysiloxane coating on the inner wall....
Mass Spectrometry: Aromatic Compound Fragmentation
Mass Spectrometers