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

Abstract

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 Epicloë 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.

Natural sesquiterpenoids

“…2,3 The occurrence, bioactivity, biosynthesis and chemical synthesis of cyclopentane sesquiterpenoids isolated from this type of microorganism have been reviewed. 4 The sesquiterpenoids and other chemical constituents of plants of the Illicium 5 and Jatropha genera 6 have been examined, whilst a review on the syntheses of some of the sesquiterpenes of the former genus has appeared. 7 A chemosystematic study of eleven species of the Lactuca genus (Asteraceae) has been carried out using sesquiterpene lactones as chemotaxonomic markers.…”

Rapid assembly of complex cyclopentanes employing chiral, α,β-unsaturated acylammonium intermediates

“…Organocatalytic methods for cyclopentane synthesis have begun to emerge, however many of these methods are quite limited in scope proceeding best with arene-substituted substrates. 16 To address the challenge of efficient enantioselective construction of stereochemically rich cyclopentanes, a common motif in bioactive natural products 17 and pharmaceuticals (Fig. 1a), we sought to design an organocascade process that could rapidly assemble these carbocycles from readily available materials.…”

GaCl3-Mediated “Inverted” Formal [3 + 2]-Cycloaddition of Donor–Acceptor Cyclopropanes to Allylic Systems

“…As a result, DACs are widely used as convenient precursors to assemble functionally substituted five-membered carbocycles . As the cyclopentane skeleton is widespread in many synthetic and natural biologically active compounds, such as prostaglandins, steroids, terpenoids etc., various methods to assemble the cyclopentane skeleton are developed and new variants are searched for.…”