Germacrene B – a central intermediate in sesquiterpene biosynthesis

• Houchao Xu and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 186–203, doi:10.3762/bjoc.19.18

• reprotonation at C-4 and cyclisation to K or reprotonation at C-10 and cyclisation to L, which represent possible precursors of guaianes (Scheme 5B). For all four intermediates I–L different stereochemistries may be realised. In principle, these reactions may be enzyme catalysed or proceed without enzyme

• catalysis, e.g., during chromatographic purifications of compounds from complex extracts. In the latter case, because of the achiral nature of 1, racemic mixtures are expected, while enzyme products should usually be enantiomerically pure or enriched. Eudesmanes The eudesmane skeleton can arise by

Synthesis of odorants in flow and their applications in perfumery

• Merlin Kleoff,
• Paul Kiler and
• Philipp Heretsch

Beilstein J. Org. Chem. 2022, 18, 754–768, doi:10.3762/bjoc.18.76

• esters with mainly fruity odor profiles are obtained in moderate to excellent yields. Some selected esters (14–16) and their odor profiles are shown in Scheme 4 [32]. Related methods for the esterification of natural occurring alcohols, such as geraniol, utilizing immobilized enzyme-catalysis in packed

Synthetic strategies toward 1,3-oxathiolane nucleoside analogues

• Umesh P. Aher,
• Dhananjai Srivastava,
• Girij P. Singh and
• Jayashree B. S

Beilstein J. Org. Chem. 2021, 17, 2680–2715, doi:10.3762/bjoc.17.182

Selected peptide-based fluorescent probes for biological applications

• Debabrata Maity

Beilstein J. Org. Chem. 2020, 16, 2971–2982, doi:10.3762/bjoc.16.247

• biological applications. Review Nucleoside triphosphates detection Nucleoside triphosphates play crucial roles in several biological processes including energy transduction, cellular respiration, enzyme catalysis, and signaling [35][36][37][38]. They are the most targeted anionic species because of their

Recent developments in enantioselective photocatalysis

• Callum Prentice,
• James Morrisson,
• Andrew D. Smith and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

• –H activations, visible-light-induced photocatalysis, electrosynthesis, enzyme catalysis, and others. Each of these techniques aims at accessing complex molecules while limiting ecological footprint. Over the last decade, the metal-catalyzed C–H activation established itself as one of the most

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

• ][188][189][190]. Supramolecular photocatalysts are an interesting class of materials which utilise non-bonding interactions to control photochemical processes, a biomimetic strategy that imitates enzyme catalysis [191]. Supramolecular self-assemblies and coordination polymers based on perylene diimide

Oligomeric ricinoleic acid preparation promoted by an efficient and recoverable Brønsted acidic ionic liquid

• Fei You,
• Xing He,
• Song Gao,
• Hong-Ru Li and
• Liang-Nian He

Beilstein J. Org. Chem. 2020, 16, 351–361, doi:10.3762/bjoc.16.34

• process efficiency. Moreover, the byproduct formation and the resulting product coloration reduce the product quality. To address the above issues, the enzyme catalysis is proposed accordingly. Nevertheless, the high cost, low efficiency and operational unstability of enzymatic reaction make it difficult

New standards for collecting and fitting steady state kinetic data

• Kenneth A. Johnson

Beilstein J. Org. Chem. 2019, 15, 16–29, doi:10.3762/bjoc.15.2

• kcat/Km. Keywords: computer simulation; data fitting; enzyme catalysis; induced-fit; Michaelis constant; specificity constant; Review When Henri, Michaelis and Menten derived the equation for steady state enzyme turnover, they chose to define the rate in terms of Vmax and the substrate dissociation

• different conclusion: We can now see that depending on the intrinsic rate constants, Km can be less than, greater than, or equal to the Kd. Thus, in the absence of additional information, Km cannot be interpreted to imply anything about the intrinsic rate and equilibrium constants governing enzyme catalysis

Dispersion interactions

• Peter R. Schreiner

Beilstein J. Org. Chem. 2018, 14, 3076–3077, doi:10.3762/bjoc.14.286

• , enzyme catalysis, and much more. Hence, this thematic issue covers selected aspects of the role LD plays for structures and reactivity. Naturally, it addresses diverse topics for which LD is particularly apparent. Peter R. Schreiner Giessen, November 2018 Dispersion = attractive part of the van-der-Waals

Local energy decomposition analysis of hydrogen-bonded dimers within a domain-based pair natural orbital coupled cluster study

• Ahmet Altun,
• Frank Neese and
• Giovanni Bistoni

Beilstein J. Org. Chem. 2018, 14, 919–929, doi:10.3762/bjoc.14.79

• importance for regulating molecular properties like polarizability [1] and in various biochemical processes, including protein folding [2] and stability [3], replication of DNA and RNA [4], enzyme catalysis [5], proton relay mechanism [6], and drug delivery [7]. Energy decomposition analysis (EDA) schemes

Phosphodiester models for cleavage of nucleic acids

• Satu Mikkola,
• Tuomas Lönnberg and
• Harri Lönnberg

Beilstein J. Org. Chem. 2018, 14, 803–837, doi:10.3762/bjoc.14.68

• molecules is useful for testing the validity of computational methods utilized for the generation of energy landscapes for enzyme catalysis [15][16][17]. Many nucleases are metalloenzymes containing two catalytically active metal ions. Small molecular models offer an excellent tool to study the cooperative

• introductory part, phosphorothiolate oligonucleotides containing a bridging 3´- or 5´-thiosubstitution, are used as mechanistic probes of enzyme catalysis. Non-bridging thiosubstitution, in turn, creates RP and SP diastereomeric phosphorothioate linkages which have extensively been used for elucidation of the

Sulfation and amidinohydrolysis in the biosynthesis of giant linear polyenes

• Hui Hong,
• Markiyan Samborskyy,
• Katsiaryna Usachova,
• Katharina Schnatz and
• Peter F. Leadlay

Beilstein J. Org. Chem. 2017, 13, 2408–2415, doi:10.3762/bjoc.13.238

• Bacterial modular polyketide synthases (PKSs) follow an assembly-line paradigm for enzyme catalysis, in which each round of chain extension requires a different set, or module, of enzymatic activities [1][2][3][4]. Among the more remarkable natural products derived by this pathway is the giant linear

Selective enzymatic esterification of lignin model compounds in the ball mill

• Ulla Weißbach,
• Saumya Dabral,
• Laure Konnert,
• Carsten Bolm and
• José G. Hernández

Beilstein J. Org. Chem. 2017, 13, 1788–1795, doi:10.3762/bjoc.13.173

• the advantages of enzyme catalysis and mechanochemistry. Under the described conditions, the primary aliphatic hydroxy groups present in the substrates were selectively modified by the biocatalyst to afford monoesterified products. Amongst the tested lipases, CALB proved to be the most effective

From chemical metabolism to life: the origin of the genetic coding process

• Antoine Danchin

Beilstein J. Org. Chem. 2017, 13, 1119–1135, doi:10.3762/bjoc.13.111

• the basic level on which life manages information [38]. Asymmetry has an important consequence: It creates a set of highly stereospecific environments, leaving room for a particular complement, as described by Fisher in his lock-and-key image of enzyme catalysis [39], or in the widespread image of the

Synthesis and enzymatic ketonization of the 5-(halo)-2-hydroxymuconates and 5-(halo)-2-hydroxy-2,4-pentadienoates

• Tyler M. M. Stack,
• William H. Johnson Jr. and
• Christian P. Whitman

Beilstein J. Org. Chem. 2017, 13, 1022–1031, doi:10.3762/bjoc.13.101

• raises questions about how the bulk and/or electronegativity of these substrates would affect enzyme catalysis or whether some pathway enzymes have evolved to accommodate it. To address these questions, 5-halo-2-hydroxymuconates and 5-halo-2-hydroxy-2,4-pentadienoates (5-halo = Cl, Br, F) were

Evidence for an iterative module in chain elongation on the azalomycin polyketide synthase

• Hui Hong,
• Yuhui Sun,
• Yongjun Zhou,
• Emily Stephens,
• Markiyan Samborskyy and
• Peter F. Leadlay

Beilstein J. Org. Chem. 2016, 12, 2164–2172, doi:10.3762/bjoc.12.206

• gene cluster for biosynthesis of the polyketide β-lactone ebelactone in Streptomyces aburaviensis has shown that, contrary to a recently-published proposal, the ebelactone polyketide synthase faithfully follows the colinear modular paradigm. Keywords: colinearity; ebelactone; enzyme catalysis

• for our understanding of the paradigm of enzyme catalysis used by bacterial modular PKS multienzymes. As pointed out by Moss and colleagues in their review of PKS non-colinearity [10], the observation of iteration emphasises the close mechanistic link between chain extension on (wholly iterative

Biosynthesis of oxygen and nitrogen-containing heterocycles in polyketides

• Franziska Hemmerling and
• Frank Hahn

Beilstein J. Org. Chem. 2016, 12, 1512–1550, doi:10.3762/bjoc.12.148

• -one 129 by action of the O-methyltransferase JerF [50]. 1.6.2 Michael addition–lactonisation: A novel mechanism for the integration of pyran-2-ones into polyketide backbones has recently been discovered. Rhizoxin. In 2013, Hertweck and co-workers provided detailed insight into the unprecedented enzyme

• catalysis involved in the formation of 4-substituted δ-lactones and the structurally closely related glutarimides, respectively (Scheme 20) [130]. The assembly of both moieties includes a β-branching event of the polyketide carbon backbone that is mechanistically different from that occurring during

Biocatalysis for the application of CO₂ as a chemical feedstock

• Apostolos Alissandratos and
• Christopher J. Easton

Beilstein J. Org. Chem. 2015, 11, 2370–2387, doi:10.3762/bjoc.11.259

• enzyme catalysis lowers the activation barriers of the CO2 transformations to make them more energy efficient. The development of technologies that treat CO2-transforming enzymes and other cellular components as modules that may be assembled into synthetic reaction circuits will facilitate the use of CO2

Dicarboxylic esters: Useful tools for the biocatalyzed synthesis of hybrid compounds and polymers

• Ivan Bassanini,
• Karl Hult and
• Sergio Riva

Beilstein J. Org. Chem. 2015, 11, 1583–1595, doi:10.3762/bjoc.11.174

• diacid derivative of oleic acid catalyzed by dibutyltin oxide and Novozyme 435 (Figure 10) [59]. Dibutyltin oxide catalysis resulted in cross-linking and gel formation. This was not observed by enzyme catalysis, presumably due to steric hindrance which may be imposed by the active site of the enzyme

• conditions for enzyme catalysis afforded nice polymers. The obtained polymers could be cross-linked by UV light in the presence of the solid photoinitiator Iracure 270 to form hard films [69]. Several poly(amine-co-ester)s were synthesized directly from dicarboxylic acid diesters and N-alkyl- or N

Synthesis of divalent ligands of β-thio- and β-N-galactopyranosides and related lactosides and their evaluation as substrates and inhibitors of Trypanosoma cruzi trans-sialidase

• María Emilia Cano,
• Rosalía Agusti,
• Alejandro J. Cagnoni,
• María Florencia Tesoriero,
• José Kovensky,
• María Laura Uhrig and
• Rosa M. de Lederkremer

Beilstein J. Org. Chem. 2014, 10, 3073–3086, doi:10.3762/bjoc.10.324

• , 6.11; N, 10.11; found: C, 43.04; H, 5.95; N, 9.80; HRMS–ESI (m/z): [M + Na]+ calcd for C50H80N10O33Na, 1371.4781; found, 1371.4797. Enzyme catalysis Compounds 11, 13, 16, 18, 20, and 22–24 were incubated with TcTS in 20 mM Tris–HCl, pH 7 buffer, 30 mM NaCl, containing 1 mM 3’-sialyllactose as donor, in

First chemoenzymatic stereodivergent synthesis of both enantiomers of promethazine and ethopropazine

• Paweł Borowiecki,
• Daniel Paprocki and
• Maciej Dranka

Beilstein J. Org. Chem. 2014, 10, 3038–3055, doi:10.3762/bjoc.10.322

• aim of this study was to take advantage of the extraordinary properties of enzyme catalysis and develop a new method based on lipase-mediated kinetic resolution (KR) of 1-(10H-phenothiazin-10-yl)propan-2-ol enantiomers, which combined with convenient chemical reactions could provide a simple and

A green approach to the synthesis of novel phytosphingolipidyl β-cyclodextrin designed to interact with membranes

• Yong Miao,
• Florence Djedaïni-Pilard and
• Véronique Bonnet

Beilstein J. Org. Chem. 2014, 10, 2654–2657, doi:10.3762/bjoc.10.278

• of two chains, can form nanoparticles giving low critical aggregation concentration (CAC) [9]. Moreover, to the best of our knowledge, only few green approaches were described to modify cyclodextrins (enzyme catalysis [8][9], green solvents [10]). The use of phytosphingosine as a sustainable

Chiral phosphines in nucleophilic organocatalysis

• Yumei Xiao,
• Zhanhu Sun,
• Hongchao Guo and
• Ohyun Kwon

Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218

[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

• enzyme catalysis [34], but such approaches may not be suitable for terpenes that are in many cases unstable under acidic conditions or may tend to thermal rearrangements [35]. The successful formation of a completely deuterated natural product (up to 90% 2H) by fermentation has recently been reported for