Pollen Growth Regulator, Fusanolide A, and a Related Metabolite from Fusarium sp.

Abstract

Fusanolides A (1) and B (2) were isolated from cultures of the fungus Fusarium sp. as pollen growth regulators and their structures were established by spectroscopic evidence. 1 completely inhibited pine pollen germination and tea pollen tube growth at a concentration of 300 mg/l, but 2 showed no inhibitory effect on them at the same concentration.

One‐Flask Tethered Ring Closing Metathesis–Electrocyclic Ring Opening for the Highly Stereoselective Synthesis of Conjugated Z/E‐Dienes

“…To conclude the synthesis of fusanolide A, we tested several macrolactonization methods, [66] including those developed by Mukaiyama, [67] Yamaguchi, [68] and Shiina, [69] unfortunately, to no avail. Interestingly, upon inspection of all the spectroscopic data published for fusanolide A, [4] we discovered that these are identical to those observed by us for the macrolactonization precursor (R)-9. On the basis of our results, it is not possible to state whether fusanolide A is actually a natural product with the structure depicted in Scheme 4, which underwent hydrolytic ring opening to (R)-9 during isolation, or if the structure of fusanolide A should be revised to (9R,2Z,4E)-8-hydroxydecadienoic acid (9).…”

“…Shimada et al did not assign an absolute configuration to the metabolite designated as fusanolide A {[α] D 20 = -4.9 (c = 1.0, CH 3 OH)}. [4] We suggest, based on a comparison of the specific rotation of our synthetic material derived from (R)-propylene oxide, assignment of an Rconfiguration to the natural product. Remarkably, while our work was in progress, Rukachaisirikul et al described the first isolation and structural elucidation of a novel natural product from the marine fungus Curvularia sp., to which the structure of (R)-9 and the name curvulalic acid were assigned.…”

“…Fusanolides A and B are fungal metabolites isolated by Shimada et al from Fusarium sp. [4] Fusanolide A acts as a pollen growth and germination inhibitor, which might be of interest for the development of new herbicides, whereas fusanolide B was found to be inactive in this respect. Based on spectroscopic evidence, Shimada et al assigned the structures of tenmembered lactones to both fusanolides.…”

“…This structural motif is often found in macrocyclic and acyclic polyenes, for example, the macrolactins, [1] which exhibit antiviral activity, or the iejimalides, [2] which have very recently been extensively tested for their cytotoxic activity against certain tumor cell lines. [3] In the growing family of natural products containing a ten-membered lactone structure, so called nonenolides, we are aware of two examples with an endocyclic Z/E-diene unit; fusanolide A [4] and stagonolide E, [5] which were both isolated from fungal plant pathogens. In addition, some natural products such as the microtubule-stabilizing macrolide (-)-zampanolide, [6] the clerodane diterpene argutin A, [7] and the lipoglycodepsipeptide antibiotics of the ramoplanin family [8,9] are conjugates of (2Z,4E)-configured dienoic acids 1a-e, which constitute the lipid side chain of the natural product and are attached to the macrocyclic or polycyclic core either as an ester or as an amide (Figure 1).…”

Nonanolides of Natural Origin: Structure, Synthesis, and Biological Activity

“…Montanense Marine-derived fungus [27] Fusanolides A, B (6, 7) Fusarium sp. Fungus [28] Modiolides A, B (8,9) Paraphaeosphaeria sp. (N-119); Periconia siamensis (CMUGE015) Marine-derived fungus [10,11] Sch 642305 (57) Penicillium verrucosum; septofusidium sp.…”