Microscopic Mass Spectrometry Imaging Reveals Specific Distributions of Curcumin Species Inside Dried Turmeric

Introduction

Plants contain a variety of secondary metabolites, many of which are known to be various useful substances, as represented by spices and herbal medicines. To date, however, few reports have examined the 3-dimensional distribution of those substances. In this Application Note, the spatial distribution of curcumin, which is one of the main components of turmeric root, was visualized using a dried turmeric sample. Because dried turmeric samples are extremely hard and sectioning was impossible with a conventional cryomicrotome, we developed a new sectioning method in this research and analyzed the 2- dimensional distributions of sections cut in different directions. The result suggests that curcumin forms tube-shaped compartments in the turmeric root. The distributions of curcumin analogues were also found to be similar to that of curcumin. This new perspective in botany, that is, the specific distributions of secondary metabolites in plants, was revealed by high spatial resolution mass spectrometry imaging (MSI) using the Shimadzu iMScope imaging mass microscope. (Fig. 1 shows the new model, iMScope QT.) In the future, knowledge of the specific distributions of components in plants is expected to contribute to improvement of production processes such as improved extraction methods for active ingredients.

April 1, 2021 GMT