02414nas a2200169   4500008004100000022001400041245011400055210006900169260001500238520182900253100001902082700002302101700002302124700001902147700002302166856005502189       2015                        eng d  a1618-264200aSpatial chemo-profiling of hypericin and related phytochemicals in Hypericum species using MALDI-HRMS imaging0 aSpatial chemoprofiling of hypericin and related phytochemicals i  c08-03-20153 a<p>Advanced analytical imaging techniques, including matrix-assisted laser desorption/ionization high-resolution mass spectrometry (MALDI-HRMS) imaging, can be used to visualize the distribution, localization, and dynamics of target compounds and their precursors with limited sample preparation. Herein we report an application of MALDI-HRMS imaging to map, in high spatial resolution, the accumulation of the medicinally important naphthodianthrone hypericin, its structural analogues and proposed precursors, and other crucial phytochemical constituents in the leaves of two hypericin-containing species, Hypericum perforatum and Hypericum olympicum. We also investigated Hypericum patulum, which does not contain hypericin or its protoforms. We focused on both the secretory (dark glands, translucent glands, secretory canals, laminar glands, and ventral glands) and the surrounding non-secretory tissues to clarify the site of biosynthesis and localization of hypericin, its possible precursors, and patterns of localization of other related compounds concomitant to the presence or absence of hypericin. Hypericin, pseudohypericin, and protohypericin accumulate in the dark glands. However, the precursor emodin not only accumulates in the dark glands but is also present outside the glands in both hypericin-containing species. In hypericin-lacking H. patulum, however, emodin typically accumulates only in the glands, thereby providing evidence that hypericin is possibly biosynthesized outside the dark glands and thereafter stored in them. The distribution and localization of related compounds were also evaluated and are discussed concomitant to the occurrence of hypericin. Our study provides the basis for further detailed investigation of hypericin biosynthesis by gene discovery and expression studies.</p>
1 aKusari, Souvik1 aSezgin, Selahaddin1 aNigutova, Katarina1 aCellarova, Eva1 aSpiteller, Michael  uhttp://link.springer.com/10.1007/s00216-015-8682-6