Mechanistic investigations on multiproduct β-himachalene synthase from Cryptosporangium arvum

• Jan Rinkel and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2019, 15, 1008–1019, doi:10.3762/bjoc.15.99

• or multiple compounds, are terpene synthases (TSs). These enzymes are able to guide complex cascade reactions from structurally simple oligoprenyl diphosphates to often complex, polycyclic products [4][5][6] circumventing the low selectivity observed for carbocationic reactions by a defined active

• expression, protein purification, incubation experiments with isotopically labelled precursors, preparative scale incubation and synthesis of (2-13C)DMAPP. The amino acid sequence of HcS, a phylogenetic tree of bacterial terpene synthases, SDS-PAGE analysis of the recombinant protein, listed NMR data for 1

Stereochemical investigations on the biosynthesis of achiral (Z)-γ-bisabolene in Cryptosporangium arvum

• Jan Rinkel and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2019, 15, 789–794, doi:10.3762/bjoc.15.75

• transformations are ubiquitous, which diminishes the hard border between achiral and chiral. One intriguing example for this kind of reactivity is represented by terpene synthases (TSs), arguably building up the class of natural products with the highest density of stereochemical information, the terpenes. By

Volatiles from three genome sequenced fungi from the genus Aspergillus

• Jeroen S. Dickschat,
• Ersin Celik and
• Nelson L. Brock

Beilstein J. Org. Chem. 2018, 14, 900–910, doi:10.3762/bjoc.14.77

• encoded terpene synthases for each strain. Besides terpenes, a series of aromatic compounds and volatiles derived from fatty acid and branched amino acid metabolism were identified. Some of these compounds have not been described as fungal metabolites before. For the compound ethyl (E)-hept-4-enoate known

• . Volatiles emitted by Aspergillus kawachii NBRC 4308. Volatiles emitted by Aspergillus clavatus NRRL 1. Supporting Information Supporting Information File 62: Phylogenetic tree of fungal type I terpene synthases, experimental procedures and NMR spectra of synthetic compounds. Acknowledgements This work was

18-Hydroxydolabella-3,7-diene synthase – a diterpene synthase from Chitinophaga pinensis

• Jeroen S. Dickschat,
• Jan Rinkel,
• Patrick Rabe,
• Arman Beyraghdar Kashkooli and
• Harro J. Bouwmeester

Beilstein J. Org. Chem. 2017, 13, 1770–1780, doi:10.3762/bjoc.13.171

• , revealing that the expression of one and the same terpene synthase in different heterologous hosts may yield different terpene products. Keywords: biosynthesis; Chitinophaga pinensis; Nicotiana benthamiana; structure elucidation; terpenes; Introduction Terpene synthases convert a handful of simple linear

• and achiral oligoprenyl diphosphates in just one enzymatic step into a remarkable diversity of usually polycyclic structurally complex lipophilic terpenes with multiple stereogenic centres. In their active sites type I terpene synthases contain the highly conserved aspartate-rich motif DDXX(X)(D,E

• cascade by attack of olefinic double bonds to the cationic centre, hydride shifts and Wagner–Meerwein rearrangements. The process is usually terminated by deprotonation or attack of water to yield a lipophilic terpene hydrocarbon or alcohol. Among the first investigated terpene synthases were the (+)- and

Opportunities and challenges for the sustainable production of structurally complex diterpenoids in recombinant microbial systems

• Katarina Kemper,
• Max Hirte,
• Markus Reinbold,
• Monika Fuchs and
• Thomas Brück

Beilstein J. Org. Chem. 2017, 13, 845–854, doi:10.3762/bjoc.13.85

• prevent accumulation of the desired lead structures [33]. Isoprenyl diphosphate formation Downstream of precursor formation condensation of IPP and DMAPP to longer-chain polyprenyls precedes subsequent metabolization to linear or mono- and polycyclic products, respectively, by the terpene synthases [24

• diterpenes (geranylgeranyl diphosphate, GGPP) [35]. Terpene synthases Interestingly, plant metabolism can convert the universal aliphatic diterpene precursor GGPP into thousands of different terpene structures with high structural complexity and elaborately functional decorations [41]. While the structural

• synthases (TPS) are classified into three groups which mainly comprise α-helical structures that are designated as α-, β- and γ-domains [45]. Structural and catalytic diversity, especially of plant terpene synthases, originate in various combinations of these domains [46]. The three groups of terpene

Mechanistic investigations on six bacterial terpene cyclases

• Patrick Rabe,
• Thomas Schmitz and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2016, 12, 1839–1850, doi:10.3762/bjoc.12.173

• fujikuroi shows a relaxed stereochemical course in this aspect [61]. Conclusion We have isolated and characterized the enzyme products of six bacterial terpene synthases by extensive one and two-dimensional NMR spectroscopic analysis and determination of the optical rotary powers. In total, two terpene

• experiments with (13-13C)FPP and all six purified recombinant terpene synthases were performed to investigate the stereochemical course of the biosynthesis of the terminal E- and Z-methyl groups and to locate this diagnostic 13C marker by NMR spectroscopy in the obtained products. All six enzymes showed a

• synthases from Streptomyces viridochromogenes ((−)-α-amorphene (1) and (−)-7-epi-α-eudesmol synthase (4)), the (+)-T-muurolol synthase (2) from Roseiflexus castenholzii, the (+)-4-epi-cubebol synthase (3) from Streptosporangium roseum, the (−)-γ-cadinene synthase (5) from Chitinophaga pinensis and the

Recent highlights in biosynthesis research using stable isotopes

• Jan Rinkel and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2015, 11, 2493–2508, doi:10.3762/bjoc.11.271

• combined in vivo and in vitro labeling techniques to achieve a better understanding of nature’s astonishing mechanistic toolbox utilized by terpene synthases. Additionally, the unexpected outcome of the initial feeding experiment gives an ideal example as to why isotopic labeling experiments are not at all