Biosynthesis of α-pyrones

• Till F. Schäberle

Beilstein J. Org. Chem. 2016, 12, 571–588, doi:10.3762/bjoc.12.56

• receptor, i.e., the PluR protein, leads to the activation of the Photorhabdus clumping factor (PCF) operon (pcfABCDEF). The phenotypic change observed due to PCF expression was cell clumping, which in turn contributed to insect toxicity [14]. Structurally related are the pseudopyronines A (55), B (56), and

• ]. Recently, the biosynthetic origin of the pseudopyronines A (55) and B (56) in Pseudomonas putida BW11M1 was clarified – and again two chains are fused to yield the final products [86]. Thus, it can be assumed that this mechanism is exemplified quite often in natural products. Therefore, in the next

• dimerization is essential [63]. The pseudopyronine synthase PyrS represents a homologue of PpyS. Using PpyS from Pseudomonas sp. GM30, it was analyzed if this KS is also involved in the formation of α-pyrones. The two pseudopyronines A (55) and B (56) have been up to now isolated from different Pseudomonas

A novel and widespread class of ketosynthase is responsible for the head-to-head condensation of two acyl moieties in bacterial pyrone biosynthesis

• Darko Kresovic,
• Florence Schempp,
• Zakaria Cheikh-Ali and
• Helge B. Bode

Beilstein J. Org. Chem. 2015, 11, 1412–1417, doi:10.3762/bjoc.11.152

• mechanism of pyrone formation has been investigated by amino acid exchange and bioinformatic analysis. Additionally, the evolutionary origin of PpyS has been studied by phylogenetic analyses also revealing homologous enzymes in Pseudomonas sp. GM30 responsible for the biosynthesis of pseudopyronines

• including a novel derivative. Moreover this novel class of ketosynthases is only distantly related to other pyrone-forming enzymes identified in the biosynthesis of the potent antibiotics myxopyronin and corallopyronin. Keywords: cell–cell communication; ketosynthase; photopyrones; pseudopyronines; quorum

• possible that pseudopyronines might also serve as a communication signal in strain GM30 and other Pseudomonas strains, which are generally rich in cell–cell communication signals [31][32][33][34][35]. In summary we have shown that two unusual ketosynthases are responsible for the formation of photopyrones

Identification and isolation of insecticidal oxazoles from Pseudomonas spp.

• Florian Grundmann,
• Veronika Dill,
• Andrea Dowling,
• Aunchalee Thanwisai,
• Edna Bode,
• Narisara Chantratita,
• Richard ffrench-Constant and
• Helge B. Bode

Beilstein J. Org. Chem. 2012, 8, 749–752, doi:10.3762/bjoc.8.85

• (Supporting Information File 1, Figure S2) and NMR analysis (Supporting Information File 1, Tables S1–S6). Whereas the structures 1 and 2 could be identified as pseudopyronines A (1, 267.4 m/z [M + H]+, C16H26O3) and B (2, 295.4 m/z [M + H]+, C18H30O3) [5][6][7], three other compounds were identified as the

• to the overall insecticidal activity of the investigated Pseudomonas strains. Structures of pseudopyronines A (1) and B (2) and natural oxazoles (3–8) as well as synthetic oxazole derivatives (9–11). All natural and synthetic oxazoles show the characteristic MS fragment 130 m/z [M + H]+. The