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Anal Bioanal Chem (2014) 406:695704 DOI 10.1007/s00216-013-7496-7
RESEARCH PAPER
Analysis of cyathane-type diterpenoids from Cyathus striatus and Hericium erinaceus by high-resolution MALDI MS imaging
Dhaka Ram Bhandari & Tian Shen & Andreas Rmpp &
Holger Zorn & Bernhard Spengler
Received: 16 August 2013 /Revised: 21 October 2013 /Accepted: 7 November 2013 /Published online: 28 November 2013 # Springer-Verlag Berlin Heidelberg 2013
Abstract Fungal secondary metabolites in both fruiting bodies and pellets from submerged cultures of basidiomycetes were analyzed by atmospheric pressure matrix-assisted laser desorption/ionization-mass spectrometry imaging at a lateral resolution of 15 m, a mass resolution of 140,000 at m/z 200 and a mass accuracy of better than 2 ppm. The striatals A, B, C, and D, and a number of erinacine type metabolites were detected in the basidiomycetes Cyathus striatus and Hericium erinaceus, respectively. The two fungi were selected as model species, as they are well-known for efficient production of terpenoid secondary metabolites with interesting biological activities, e.g., antibacterial, fungicidal, cytotoxic properties, and stimulating effects on nerve growth factor synthesis. The localization of metabolites revealed a mostly homogeneous distribution of the striatals in the pellets of C. striatus, while a concentration gradient, increasing to the center, was observed in the pellets of H. erinaceus. A mostly homogeneous distribution of metabolites was also found in the fruiting body of H. erinaceus.
Keywords Foods/beverages . Mass spectrometry imaging .
Fungi . Secondary metabolites . MALDI . High resolution
Introduction
Fungi of the class of basidiomycetes are known to form a broad spectrum of secondary metabolites. A number of uncommon cyathane-type diterpenoids with high biological activity, e.g., striatals from Cyathus spp., sarcodonins from Sarcodon spp., and erinacines from Hericium spp. were isolated and characterized [15]. These metabolites possess a cyathane skeleton consisting of five-, six-, and seven-membered rings (Fig. 1). Cyathus striatus, a member of the family Nidulariaceae, which are known as birds nest fungi, produces bioactive cyathane-type metabolites such as the striatals A, B, C, and D (Fig. 1).
The above-mentioned compounds exert antibacterial, fungicidal, and cytotoxic properties [6, 8, 9]. Fungal extracts prepared from C. striatus showed significant inhibitory effects on the NF-B activation pathway, potentially useful in cancer therapy [10].
Hericium erinaceus is an edible mushroom belonging to the family Hericiaceae and has been...