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

• identified in nearly all investigated bacterial strains that produce phenazine compounds [3][6]. Other genes have been shown to play a role in the regulation of phenazine biosynthesis. In P. fluorescens, the transcriptional regulation involves the quorum sensing proteins PhzR/PhzI, the positive two-component

• regulation of the biosynthesis of phenazine natural products. In a previous study, we described the biosynthetic gene cluster for prenylated phenazines from Streptomyces anulatus (Figure 1) [11]. This cluster contained the seven core phenazine biosynthesis genes, the mevalonate pathway genes and a

• individual genes of this cluster for the biosynthetic pathway and for its regulation. The genes inactivated in this study are summarized in Table 1, and a complete list of the genes contained in the insert of cosmid ppzOS04 is given in Table S1 of Supporting Information File 1. Results and Discussion

Conserved and species-specific oxylipin pathways in the wound-activated chemical defense of the noninvasive red alga Gracilaria chilensis and the invasive Gracilaria vermiculophylla

• Martin Rempt,
• Florian Weinberger,
• Katharina Grosser and
• Georg Pohnert

Beilstein J. Org. Chem. 2012, 8, 283–289, doi:10.3762/bjoc.8.30

• potential of Gracilaria spp. is discussed. Keywords: activated chemical defense; invasive species; oxylipins; prostaglandins; red algae; regulation; Introduction The red alga Gracilaria chilensis is native along the Chilean coast and is commercially farmed for the production of agar hydrocolloids [1

• chemical defense against epiphytism has been demonstrated. This alga has two major lines of defense, including a rapid wound-activated production of oxylipins and a slower induced defense involving the up regulation of phospholipases and lipoxygenases and subsequent fatty-acid transformation [3][5]. Among

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

• Marcus Baumann,
• Ian R. Baxendale,
• Steven V. Ley and
• Nikzad Nikbin

Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57

A bivalent glycopeptide to target two putative carbohydrate binding sites on FimH

• Thisbe K. Lindhorst,
• Kathrin Bruegge,
• Andreas Fuchs and
• Oliver Sperling

Beilstein J. Org. Chem. 2010, 6, 801–809, doi:10.3762/bjoc.6.90

• light of very recent findings, our observations as well as results with other multivalent ligands, might be well explained by an allosteric model of FimH-mediated adhesion [35]. It has been reported that interdomain allosteric regulation can lead to a catch bond mechanism of adhesion in which the

• regulation of the ligand-receptor interaction. Experimental Docking studies Computer-aided modeling to estimate the spacer lengths of a bivalent glycopeptide ligand to allow bridging of two putative binding sites on FimH was carried out using FlexX flexible docking and consensus scoring, implemented in Sybyl

Bioorthogonal metabolic glycoengineering of human larynx carcinoma (HEp-2) cells targeting sialic acid

• Arne Homann,
• Riaz-ul Qamar,
• Sevnur Serim,
• Petra Dersch and
• Jürgen Seibel

Beilstein J. Org. Chem. 2010, 6, No. 24, doi:10.3762/bjoc.6.24

• effects is known [11]. Recently, the regulation of UDP-GlcNAc 2-epimerase/ManNAc kinase expression on the transcriptional level by DNA methylation was demonstrated [12] and a genetic feedback regulation for this process was proposed (Scheme 3) [13]. Ac4GlcNAz 16 or Neu5Hex 3, respectively, were incubated

The first preparative solution phase synthesis of melanotan II

• Vladimir V. Ryakhovsky,
• Georgy A. Khachiyan,
• Nina F. Kosovova,
• Elena F. Isamiddinova and
• Andrey S. Ivanov

Beilstein J. Org. Chem. 2008, 4, No. 39, doi:10.3762/bjoc.4.39

• formula Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2 (1), involved in the regulation of skin pigmentation. Production of this hormone is stimulated by irradiation of skin by the sun’s ultraviolet rays. The α-MSH triggers the skin tanning, a process in which skin tanning cells (melanocytes

Do α-acyloxy and α-alkoxycarbonyloxy radicals fragment to form acyl and alkoxycarbonyl radicals?

• Dennis P. Curran and
• Tiffany R. Turner

Beilstein J. Org. Chem. 2006, 2, No. 10, doi:10.1186/1860-5397-2-10

• coupled regulation of radical generation and removal. Among the non-chain methods, generation and removal of radicals by oxidation and reduction are important, as is the "persistent radical effect" [4]. Recently, Wille and coworkers have described a collection of innovative new transformations that they