Cyclopentane Sesquiterpenes from Fungi: Ocurrence-Bioactivity, Biosynthesis and Chemical Synthesis

The occurrence of 2,6-cyclofarnesanes in Nature is scarce and their presence has been only described in microscopic fungi. However this class of compounds constitutes an interesting group of natural products since they present specific bioactivities. This review moves on to the advances achieved in this kind of structures. These advances are presented in three parts. The first one presents the structure and biological properties of these cyclopentane derivatives. In fact, these compounds could be divided in two groups, namely, chokols, isolated from the stroma of the timothy Phleum pratens inFfected by the endophytic fungus Epicloe typhina, and cyclonerodiol and derivatives, chemically related to chokols, and found to be widespread in fungi. Both, chokols and cyclonerodiol have been described as antifungal, although other biological activities attributed to these compounds are also discussed. The second part considers the biosynthetic studies justifying the formation of cyclonerolidol from cyclization of nerolidyl pyrophosphate. The third and more extended part of the review is devoted to the achievements made in different synthetic strategies directed at some of cyclopentane sesquiterpenes.