Gloeosporone – A Macrolide Fungal Germination Self‐Inhibitor Total Synthesis and Activity

Abstract

Starting with (S)‐ or (R)‐4‐Bromo‐1,2‐epoxybutane [commercially available or readily made from (S)‐ or (R)‐malic acid], both enantiomers of the germination self‐inhibitor gloeosporone were synthesized. The absolute configuration of the natural product was thus proven to be 4S,7R,13R. Microbiological studies showed that both enantiomers of the compound cause inhibition of germination in spores of Colletotrichum gloeosporioides, and that (‐)‐gloeosporone is also active against a variety of other fungi. In order to gain some insight into the mode of action, 23Na NMR measurements and ion‐selectivity studies were undertaken; none of these experiments provided evidence for a gloeosporone–metal ion interaction.

Stereoselective synthesis of protectin D1: a potent anti-inflammatory and proresolving lipid mediator

“…Next, the Wittig-salt 7 was synthesized. The dianion of 4-pentynoic acid (11) in HMPA, 21 prepared by treatment with excess n-BuLi, was reacted with ethylene oxide (10). This afforded 7-hydroxy-hept-4-ynoic acid which was directly esterified to 18 (MeOH, catalytic H 2 SO 4 ), see Scheme 2.…”

Secondary metabolites isolated from Colletotrichum species

“…12 Various synthetic studies have been reported. [13][14][15][16][17][18][19] The structures of the major metabolites of C. gloeosporioides are shown in Fig. 1.…”

Macrocyclization by Nickel‐Catalyzed, Ester‐Promoted, Epoxide–Alkyne Reductive Coupling: Total Synthesis of (−)‐Gloeosporone

“…As shown in Table 1, the number of atoms in the targeted ring is not as important as two other variables. When the ring size was kept constant but the number of CH 2 groups between the ester and alkyne was varied, the superiority of three CH 2 units (n = 1) versus two or four such units was observed (n = 0 or 2, respectively; Table 1, entries [1][2][3][4][5][6]. With this requirement satisfied, 12-and 15-membered rings could also be prepared in this fashion, albeit with reduced efficiency ( Table 1, entries 7-10).…”