Structure and Absolute Configuration of Pseudohygrophorones A12 and B12, Alkyl Cyclohexenone Derivatives from Hygrophorus abieticola (Basidiomycetes)

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• 作者：Alexander Otto ; Andrea Porzel ; Jürgen Schmidt ; Wolfgang Brandt ; Ludger Wessjohann ; Norbert Arnold
• 刊名：Journal of Natural Products
• 出版年：2016
• 出版时间：January 22, 2016
• 年：2016
• 卷：79
• 期：1
• 页码：74-80
• 全文大小：398K
• ISSN：1520-6025

文摘

Pseudohygrophorones A¹² (1) and B¹² (2), the first naturally occurring alkyl cyclohexenones from a fungal source, and the recently reported hygrophorone B¹² (3) have been isolated from fruiting bodies of the basidiomycete Hygrophorus abieticola Krieglst. ex Gr?ger & Bresinsky. Their structures were assigned on the basis of extensive one- and two-dimensional NMR spectroscopic analysis as well as ESI-HRMS measurements. The absolute configuration of the three stereogenic centers in the diastereomeric compounds 1 and 2 was established with the aid of ³J_H,H and ⁴J_H,H coupling constants, NOE interactions, and conformational analysis in conjunction with quantum chemical CD calculations. It was concluded that pseudohygrophorone A¹² (1) is 4S,5S,6S configured, while pseudohygrophorone B¹² (2) was identified as the C-6 epimer of 1, corresponding to the absolute configuration 4S,5S,6R. In addition, the mass spectrometric fragmentation behavior of 1–3 obtained by the higher energy collisional dissociation method allows a clear distinction between the pseudohygrophorones (1 and 2) and hygrophorone B¹² (3). The isolated compounds 1–3 exhibited pronounced activity against phytopathogenic organisms.