Gold(I)-catalysed synthesis of a furan analogue of thiamine pyrophosphate

• Amjid Iqbal,
• El-Habib Sahraoui and
• Finian J. Leeper

Beilstein J. Org. Chem. 2014, 10, 2580–2585, doi:10.3762/bjoc.10.270

• , involving gold(I)-catalysed cyclisation of an alkynyl alcohol to form the furan ring. The furan analogue of thiamine diphosphate (ThDP) was also made and tested for binding to and inhibition of pyruvate decarboxylase (PDC) from Zymomonas mobilis (overexpressed in E. coli with a N-terminal His-tag). It is a

• ; pyruvate decarboxylase; thiamine diphosphate; Introduction The biologically active form of vitamin B1 is thiamine diphosphate (ThDP, 1, Figure 1), which is an essential cofactor and involved in a number of metabolic pathways, including oxidative and non-oxidative decarboxylation of α-keto acids (e.g

• synthesis of a furan-based analogue of thiamine. This analogue was converted to its diphosphate, which is another extremely potent inhibitor of ZmPDC, and could also be functionalised at the 2-position using a Friedel–Crafts acylation. Results and Discussion Synthesis of ThDP analogue 17 The key step in our

Organophosphorus chemistry

• Paul R. Hanson

Beilstein J. Org. Chem. 2014, 10, 2087–2088, doi:10.3762/bjoc.10.217

• phosphanylidenecarbenes and phosphoryl azides, and bisphosphonate ethers as promising inhibitors of geranylgeranyl diphosphate synthase (GGDPS). The articles and reviews capture the emerging potential of organophosphorus compounds and exciting opportunities in the field, and hopefully, will inspire and motivate

Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules

• Thilo Focken and
• Stephen Hanessian

Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195

• inhibitor (1996) Inhibitors of squalene synthase have sparked interest as selective cholesterol lowering agents [76][77]. The enzyme is involved in the first committed step in the cholesterol synthesis and catalyses the conversion of two molecules of farnesyl diphosphate into squalene, which is later

Synthesis of isoprenoid bisphosphonate ethers through C–P bond formations: Potential inhibitors of geranylgeranyl diphosphate synthase

• Xiang Zhou,
• Jacqueline E. Reilly,
• Kathleen A. Loerch,
• Raymond J. Hohl and
• David F. Wiemer

Beilstein J. Org. Chem. 2014, 10, 1645–1650, doi:10.3762/bjoc.10.171

• enzyme geranylgeranyl diphosphate synthase (GGDPS). Five of the new compounds show IC50 values of less than 1 μM against GGDPS with little to no activity against the related enzyme farnesyl diphosphate synthase (FDPS). The most active compound displayed an IC50 value of 82 nM when assayed with GGDPS, and

• CoA reductase (HMGCoA) is viewed as the first committed step of isoprenoid and steroid biosynthesis, and is the target of the statin class of cholesterol-lowering agents including lovastatin (1, Figure 1) and pravastatin (2) [1]. The downstream enzyme farnesyl diphosphate synthase (FDPS) is the target

• other enzymes in these pathways also may have value as drug targets. One of our interests in isoprenoid biosynthesis has been the enzyme geranylgeranyl diphosphate synthase (GGDPS), which mediates the reaction of the C15 compound farnesyl diphosphate (FPP) with the C5 isopentenyl diphosphate to form the

[²H₂₆]-1-epi-Cubenol, a completely deuterated natural product from Streptomyces griseus

• Christian A. Citron and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 2841–2845, doi:10.3762/bjoc.9.319

• observed on DMM (Figure 2). This demonstrated that all relevant terpene biosynthetic pathways including the deoxyxylulose phosphate pathway for the biosynthesis of the terpene monomers dimethylallyl diphosphate (DMAPP) and isopentenyl diphosphate (IPP) as well as polyisoprenoid biosynthesis for the linear

• precursors geranyl diphosphate (GPP) and farnesyl diphosphate (FPP) were active. However, the volatile 2 was found only in traces, while the production of 1 was completely abolished. Reasons for these findings may be that the production of 2 is under positive control of the bacterial hormone A-factor [1

Biosynthesis of rare hexoses using microorganisms and related enzymes

• Zijie Li,
• Yahui Gao,
• Hideki Nakanishi,
• Xiaodong Gao and
• Li Cai

Beilstein J. Org. Chem. 2013, 9, 2434–2445, doi:10.3762/bjoc.9.281

• engineered Corynebacterium glutamicum was used to produce guanosine-5’-diphosphate (GDP)-L-fucose, the precursor of fucosyl-oligosaccharides, from glucose and mannose [95]. L-Fucose (or its analogs) can also be prepared in vitro enzymatically in a three-step procedure (Scheme 16) [96]. Firstly, L-fuculose-1

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

• putative biosynthetic pathway for the formation of the hetisine alkaloids is derived from phytochemical data and basic biochemical transformations (Scheme 30) [167]. Cyclization of geranylgeranyl pyrophosphate (229), involving the ent-copalyl diphosphate synthase, could give ent-copalyl diphosphate (230

Caryolene-forming carbocation rearrangements

• Quynh Nhu N. Nguyen and
• Dean J. Tantillo

Beilstein J. Org. Chem. 2013, 9, 323–331, doi:10.3762/bjoc.9.37

• positioned on opposite sides of the hydrocarbon substrate due to the steric congestion at its core (note the position of NH3 throughout Figure 7), a scenario that could be probed by deuterium labeling of farnesyl diphosphate if a suitable caryolene synthase were isolated. The energetics for both pathways

• (caryol-1(11)-en-10-ol, 1) formation. Atom numbers for farnesyl diphosphate are shown. These are used in the mechanistic discussions herein; note that this numbering system differs from that generally used for caryolene and caryolenol. Alternative mechanisms for caryolene formation. Supporting

Studies on the substrate specificity of a GDP-mannose pyrophosphorylase from Salmonella enterica

• Lu Zou,
• Ruixiang Blake Zheng and
• Todd L. Lowary

Beilstein J. Org. Chem. 2012, 8, 1219–1226, doi:10.3762/bjoc.8.136

• their ability to be converted into the corresponding guanosine diphosphate mannopyranose (GDP-Manp) analogues by a pyrophosphorylase (GDP-ManPP) from Salmonella enterica was studied. Evaluation of methoxy analogues demonstrated that GDP-ManPP is intolerant of bulky substituents at the C-2, C-3, and C-4

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

• prenyltransferase gene ppzP and, downstream thereof, the genes of the mevalonate pathway for supply of the isoprenoid precursor dimethylallyl diphosphate (DMAPP). Upstream of ppzP, four genes, orf1-orf4, could be identified. Database comparisons by using BLAST and Pfam searches gave no obvious clues as to whether

Natural product biosyntheses in cyanobacteria: A treasure trove of unique enzymes

• Jan-Christoph Kehr,
• Douglas Gatte Picchi and
• Elke Dittmann

Beilstein J. Org. Chem. 2011, 7, 1622–1635, doi:10.3762/bjoc.7.191

• to be generated by the putative prephenate dehydrogenase NpR1269. Both substrates are then further transformed by the thiamin diphosphate (ThDP)-dependent enzyme NpR1276 to isomeric acyloins representing one-half of the carbon framework of scytonemin [71]. The enzyme showed a remarkable selectivity

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

• and the genetic control of Neu5Ac 1 synthesis by feedback inhibition. The accumulation of Neu5Hex 3 is proposed by incubation of 3 with the target cell line as the synthesis of Neu5Ac 1 is down-regulated [11][13]. UDP: uridine diphosphate; GNE: UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine

Investigation of acetyl migrations in furanosides

• O. P. Chevallier and
• M. E. Migaud

Beilstein J. Org. Chem. 2006, 2, No. 14, doi:10.1186/1860-5397-2-14

• proposed to involve the formation of an orthoester intermediate[7] between adjacent or remote alcohol and ester groups.[8] We aim to prepare analogues of 1''-O-acetyl adenosine diphosphate ribose (AcO-ADPR) incorporating modified acetylated ribosides, xylosides and arabinosides in place of the ribose