The chemistry of isoindole natural products

• Klaus Speck and
• Thomas Magauer

Beilstein J. Org. Chem. 2013, 9, 2048–2078, doi:10.3762/bjoc.9.243

• allows for a rapid access to a variety of members of the cytochalasin alkaloid family. The power of the intramolecular Diels–Alder strategy for the synthesis of the isoindolinone moiety was also recognized during the synthesis of aspergillin PZ (91) [73]. This secondary metabolite has a remarkable

• basis of the structural similarity between 208 and marinopyrrole A, another secondary metabolite derived from a marine Streptomyces species [156]. The common biosynthetic precursor 206 stems from a mixed nonribosomal peptide synthetase (NRPS)/polyketide synthase (PKS) pathway. The amino acid proline is

Natural products in synthesis and biosynthesis

• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 1897–1898, doi:10.3762/bjoc.9.223

• fascinating as is spectacularly demonstrated by the prominent examples of maitotoxin [3], the largest non-polymer secondary metabolite known to date, or calicheamycin (Figure 1), which possibly holds the record in carrying the most diverse functional groups including an enediyne subunit, a deoxysugar, an

Activation of cryptic metabolite production through gene disruption: Dimethyl furan-2,4-dicarboxylate produced by Streptomyces sahachiroi

• Dinesh Simkhada,
• Huitu Zhang,
• Shogo Mori,
• Howard Williams and
• Coran M. H. Watanabe

Beilstein J. Org. Chem. 2013, 9, 1768–1773, doi:10.3762/bjoc.9.205

• previously identified and characterized compounds has become a serious impediment to the discovery of new bioactive natural products. Here, genetic knockout of an unusual non-ribosomal peptide synthetase (NRPS) C-PCP-C module, aziA2, is performed resulting in the accumulation of the secondary metabolite

• implemented to “activate” secondary metabolite production [4][5]. In some instances, shot-gun cloning and expression of soil samples and bacterial symbiont genomes have led to the discovery of a representative set of natural products and enzymes, albeit typically of small biosynthetic pathways (less than 10

• or cryptic metabolites for subsequent isolation and characterization. Secondary metabolite production by microorganisms is often viewed as a line of defense against competing microbes for nutrients. Natural products like azinomycin, a DNA crosslinking agent, can offer a means of protection to the

New tridecapeptides of the theonellapeptolide family from the Indonesian sponge Theonella swinhoei

• Annamaria Sinisi,
• Barbara Calcinai,
• Carlo Cerrano,
• Henny A. Dien,
• Angela Zampella,
• Claudio D’Amore,
• Barbara Renga,
• Stefano Fiorucci and
• Orazio Taglialatela-Scafati

Beilstein J. Org. Chem. 2013, 9, 1643–1651, doi:10.3762/bjoc.9.188

• , exhibited an extremely different secondary metabolite composition. In particular, this second specimen has been found to be rich in polypeptides and, from the CHCl3 phase of the organic extract, we have identified the major member of this class as theonellapeptolide Id (1) (Figure 1). In this paper we

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

• intermediates were also investigated revealing interesting biological activities for several compounds despite their overall simple structures. Keywords: insecticidal activity; labradorin; oxazole; Pseudomonas; secondary metabolite; Findings During our search for novel natural products from entomopathogenic

Mutational analysis of a phenazine biosynthetic gene cluster in Streptomyces anulatus 9663

• Orwah Saleh,
• Katrin Flinspach,
• Lucia Westrich,
• Andreas Kulik,
• Bertolt Gust,
• Hans-Peter Fiedler and
• Lutz Heide

Beilstein J. Org. Chem. 2012, 8, 501–513, doi:10.3762/bjoc.8.57

• endophenazine B as a minor product (Figure 1) [11]. In the present study, we carried out inactivation experiments of genes on cosmid ppzOS04, followed by heterologous expression of the modified clusters and chemical analysis of secondary metabolite formation. This allowed us to investigate the function of

• quantitative differences in production reliably. We decided to use cultivation in 24 square deep-well plates (EnzyScreen BV, The Netherlands). Previous studies have shown that this greatly reduces the variability of secondary metabolite production in comparison to cultivation in Erlenmeyer flasks [14]. In

• shown to increase the production of certain antibiotics [14]. Of each mutant obtained in this study, usually three independent clones were isolated, and secondary metabolite production was determined in three parallel cultivations for each clone. The variability of production between different clones