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Search for "enzyme" in Full Text gives 553 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
The charge-assisted hydrogen-bonded organic framework (CAHOF) self-assembled from the conjugated acid of tetrakis(4-aminophenyl)methane and 2,6-naphthalenedisulfonate as a new class of recyclable Brønsted acid catalysts
Beilstein J. Org. Chem. 2020, 16, 1124–1134, doi:10.3762/bjoc.16.99
- ][31], gas separation and absorption [28][29], enzyme encapsulation [36], and even asymmetric synthesis (albeit with a framework that contained a transition metal ion) [37]. However, for the HOF and CAHOF catalysts to have a similar appeal to other regular active site distribution materials, such as
Fluorinated phenylalanines: synthesis and pharmaceutical applications
Beilstein J. Org. Chem. 2020, 16, 1022–1050, doi:10.3762/bjoc.16.91
- over the last few decades. ᴅ- or ʟ-fluorinated phenylalanines have had considerable industrial and pharmaceutical applications and they have been expanded also to play an important role as potential enzyme inhibitors as well as therapeutic agents and topography imaging of tumor ecosystems using PET
- , geometry, conformation, reactivity, and moreover the bioavailability of the analogue [1]. Fluorinated amino acids (FAAs) have considerable industrial and pharmaceutical potential [2]. Also, they have played an important role as enzyme inhibitors as well as therapeutic agents [3][4]. Moreover, they modulate
- diesters 20a–c. Partial hydrolysis followed by decarboxylation gave the N-benzyloxycarbonyl ᴅʟ-amino acid esters 22a–c, which upon enzymatic hydrolysis of the ester group using the subtilisin-type Carlsberg enzyme led to ᴅ-amino acid esters 23a–c and the corresponding Cbz-protected p, m-fluoro-, or
Fabclavine diversity in Xenorhabdus bacteria
Beilstein J. Org. Chem. 2020, 16, 956–965, doi:10.3762/bjoc.16.84
- identified. These are generated when the peptide biosynthesis starts directly with the second NRPS enzyme FclJ, which results in the formation of a dipeptide instead of the usual hexapeptide (Figure 1) [22]. Structurally related compounds are the (pre)zeamines described for Serratia plymuthica and Dickeya
Copper catalysis with redox-active ligands
Beilstein J. Org. Chem. 2020, 16, 858–870, doi:10.3762/bjoc.16.77
- -abundant metals, such as copper, with radical ligands is originally known from biological systems such as metalloenzymes [1]. Among the myriad of existing enzymes, galactose oxidase (GAO) is a copper-based enzyme performing the two-electron oxidation of galactose through a mechanism involving the metal and
- regenerates the active catalyst, thus closing the catalytic cycle. Interestingly, this catalytic behavior involving participation of the ligand framework to release electrons and store an H-atom is reminiscent of the galactose oxidase copper enzyme. A recent investigation by Martins, Davidovich and co-workers
Efficient synthesis of dipeptide analogues of α-fluorinated β-aminophosphonates
Beilstein J. Org. Chem. 2020, 16, 756–762, doi:10.3762/bjoc.16.69
- enzyme binding may depend on the C–F stereochemistry, the synthesis of such compounds with a specific configuration is very important [9][10][11]. α-Fluorinated phosphonates can be prepared by many different protocols [12][13][14][15][16]. Nucleophilic fluorination is one of the fundamental reactions in
Microwave-assisted efficient and facile synthesis of tetramic acid derivatives via a one-pot post-Ugi cascade reaction
Beilstein J. Org. Chem. 2020, 16, 663–669, doi:10.3762/bjoc.16.63
- exhibit a wide range of biological activities, including antibiotic [8], antiviral [9], antifungal [10], phytotoxic [11], cytotoxic [12][13], and enzyme inhibitory activities against bacterial DNA-directed RNA polymerase [14]. The wide range of biological activity and structural variation of this class of
Design and synthesis of diazine-based panobinostat analogues for HDAC8 inhibition
Beilstein J. Org. Chem. 2020, 16, 628–637, doi:10.3762/bjoc.16.59
- the positive control consisted of HDAC8 without inhibitor added. The substrate concentration was 5 µM, and HDAC8 concentration per well was 4 ng/µL. The reaction was initiated by addition of enzyme. The fluorogenic substrate was excited at 360 nm and the emission signal was detected at 460 nm using a
Oligomeric ricinoleic acid preparation promoted by an efficient and recoverable Brønsted acidic ionic liquid
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
Synthesis and herbicidal activities of aryloxyacetic acid derivatives as HPPD inhibitors
Beilstein J. Org. Chem. 2020, 16, 233–247, doi:10.3762/bjoc.16.25
- . Keywords: aryloxyacetic acid; herbicidal activity; 4-hydroxyphenylpyruvate dioxygenase; modification; synthesis; Introduction 4-Hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27, HPPD), which belongs to the family of non-heme FeII-containing enzymes, is a vital enzyme for tyrosine catabolism. This enzyme
- the protein receptor binding site. After the docking calculations were performed, the best binding modes were determined by docking scores and also compared with the simulated binding mode of mesotrione with AtHPPD. Enzyme inhibition study AtHPPD was prepared and purified according to the reported
- binding modes of compound I39 and I40 in a target enzyme (AtHPPD). The key residues in the active site are shown in blue sticks, the FeII is shown as a dark blue sphere, and compound I39 and I40 is shown in gray sticks. Crystal structures of I18 and III4. Simulated binding mode of mesotrione (A), compound
Understanding the role of active site residues in CotB2 catalysis using a cluster model
Beilstein J. Org. Chem. 2020, 16, 50–59, doi:10.3762/bjoc.16.7
- active site cluster model. The results revealed the significant effect of the active site residues on the relative electronic energy of the intermediates and transition state structures with respect to gas phase data. A detailed understanding of the role of the enzyme environment on the CotB2 reaction
- crystal structure of a diterpene cyclase was reported by Christianson and co-workers [22]. These structures, in conjunction with extensive biochemical work [10][13][14][23], have contributed to the understanding of mechanistic details of terpene cyclases and facilitated rational enzyme design [24
- ]. Theoretical quantum mechanical (QM) investigations on the chemistry of terpenes in the gas phase have provided a detailed understanding of the carbocation mechanisms underlying terpene synthase function [25][26][27]. Further, we have used multiscale modeling tools to study the effects of the enzyme
Synthesis of C-glycosyl phosphonate derivatives of 4-amino-4-deoxy-α-ʟ-arabinose
Beilstein J. Org. Chem. 2020, 16, 9–14, doi:10.3762/bjoc.16.2
- were inactive towards enzyme upstream of the biosynthetic pathway to undecaprenyl Ara4N, the peracetylated 4-azido derivative showed modest reduction of Ara4N incorporation into the lipid A part of Salmonella typhimurium [8]. We have recently set out to study the substrate specificity of ArnT enzymes
Bacterial terpene biosynthesis: challenges and opportunities for pathway engineering
Beilstein J. Org. Chem. 2019, 15, 2889–2906, doi:10.3762/bjoc.15.283
- potential with molecular structure is severely restricted. The canonical terpene biosynthetic pathway uses a single enzyme to form a cyclized hydrocarbon backbone followed by modifications with a suite of tailoring enzymes that can generate dozens of different products from a single backbone. This
- a linear polyene with branching methyl groups that form the core hydrocarbon structure in a single enzyme-catalyzed step [9]. The enzyme, which is called terpene cyclase, holds the linear methyl-branched polyene in a defined conformation that initiates a series of carbocation-driven cyclizations and
- placed on terpene pathways from bacteria, as their biosynthetic pathways usually have the genes encoding the terpene cyclase and modifying enzyme in close proximity, which simplifies both analysis and pathway engineering. The review will begin with a brief description of terpene families with a special
Emission and biosynthesis of volatile terpenoids from the plasmodial slime mold Physarum polycephalum
Beilstein J. Org. Chem. 2019, 15, 2872–2880, doi:10.3762/bjoc.15.281
- primers (Table S2, Supporting Information File 1), cloned into pEXP5 CT/TOPO vector (https://www.thermofisher.com) and fully sequenced. Terpene synthase enzyme assays pEXP5 CT/TOPO vector containing individual PpolyTPS genes was transformed into E. coli strain BL21 Codon Plus (DE3). Heterologous
- expression of individual PpolyTPS genes in E. coli and recombinant protein preparation and terpene synthase enzyme assays were performed as previously described [42]. Each PoplyTPS recombinant protein was tested with both geranyl diphosphate and farnesyl diphosphate as substrates and terpene products were
- Supporting Information File 612: Additional figures and tables. Acknowledgements Wangdan Xiong was supported by a scholarship from the China Scholarship Council. Kevin Chen from Farragut High School, Knoxville, is acknowledged for his assistance with chemical profiling and TPS enzyme assays for this project.
Palladium-catalyzed synthesis and nucleotide pyrophosphatase inhibition of benzo[4,5]furo[3,2-b]indoles
Beilstein J. Org. Chem. 2019, 15, 2830–2839, doi:10.3762/bjoc.15.276
- reported diindolofurans 6a–e (Figure 3) [31]. All compounds show significant inhibition of enzyme h-NPP-3 (Table 3) and most of them of the enzyme h-NPP-1. Compound 5a, containing a phenyl substituent, and compound 5e, containing a p-methoxyphenyl group, showed a selective inhibitory response towards
- nucleotide pyrophosphatase enzyme h-NPP-3. In case of 5e, an inhibitory value IC50 ± SEM = 0.26 ± 0.01 µM was observed which, thus, might be considered as potential inhibitor of h-NPP-3. Compound 5c with an inhibitory value for h-NPP-1 of IC50 ± SEM = 1.29 ± 0.07 µM was more active against NPP1 than against
- towards h-NPP-3 (IC50 ± SEM = 0.13 ± 0.06 and 0.28 ± 0.04, respectively). In fact, they had no interaction with enzyme h-NPP-1. Compound 6a, containing a tolyl group, was active against both h-NPP-1 and h-NPP-3, but was more selective to h-NPP-1 with an inhibitory value of IC50 ± SEM = 0.11 ± 0.06 µM. In
Chemical tuning of photoswitchable azobenzenes: a photopharmacological case study using nicotinic transmission
Beilstein J. Org. Chem. 2019, 15, 2812–2821, doi:10.3762/bjoc.15.274
- into the corresponding cis configuration [1]. The reverse reaction can be initiated with a different wavelength. In a biological context, this photochromism was exploited first by Erlanger and colleagues for enzyme inhibitors in 1968 [2], and ion channels in 1971 [3]. Their ingenious approach was
A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions
Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264
- 2000, reported for the first time, a crucial modification of a glassy carbon electrode via chemical immobilization of ᴅ-amino acid oxidase (D-AOx) as enzyme and 1-aminopropyl-1'-methyl-4,4'-dipyridinium iodide (ADPy) as electron mediator and thus prepared electrode D-AOx/ADPy/GC. Electrochemical
- transformations using various catalysts as chiral sources has been studied in greater detail than the other strategies mentioned in this review. As per our classification, we further categorize this class into metal catalysts, enzyme catalysts and organocatalysts. Metal catalysts: In 1992, Amundsen and co-workers
- potentiostatic electrolysis of a mixture of ketones 129 with tertiary amines 128 in an undivided cell under standard conditions furnished C1-alkylated tetrahydroisoquinolines 131 in high yields with excellent enantioselectivity (Scheme 42). Enzyme catalysts: In 1981, Tischer’s group reported the electroenzymatic
Nanangenines: drimane sesquiterpenoids as the dominant metabolite cohort of a novel Australian fungus, Aspergillus nanangensis
Beilstein J. Org. Chem. 2019, 15, 2631–2643, doi:10.3762/bjoc.15.256
- terpene synthase family, showing similarity to haloacid dehalogenase (HAD)-like hydrolases [21]. Thus, we suspected that a related enzyme may be involved in the biosynthesis of the nanangenines, and used the amino acid sequence of AstC to probe the A. nanangensis genome. We also hypothesised that the acyl
- analyses above, a biosynthetic pathway to the nanangenines was proposed (Figure 3). Unlike the ast cluster, where there are multiple HAD-like enzymes encoded (one terpene synthase and two phosphatases), the putative nanangenine cluster only encodes one such enzyme, FE257_006542. However, given that
- . The C-6 and C-8 lipid chain is likely produced by the HR-PKS encoded by gene FE257_006541, while the acylation could be attributed to the enzyme encoded by FE257_006545, which contains the conserved domain of the alpha/beta-hydrolase fold superfamily (which includes thioesterases and acyltransferases
Probing of local polarity in poly(methyl methacrylate) with the charge transfer transition in Nile red
Beilstein J. Org. Chem. 2019, 15, 2552–2562, doi:10.3762/bjoc.15.248
- polymer films, in which the values of the glass transition temperature (Tg) and segmental mobilities were found to be altered. Likewise, this holds for transport properties, including polymer nanocapsule membrane permeability [1], enzyme-triggered bacterial sensors [2][3][4][5] and intelligent self
- [1] and segment mobilities inferred [13], respectively. For other purposes the oxazine tracer dye Nile red (NR, Figure 1) served as a local probe to enable the study of degradation of enzyme labile polymersomes [14]. The same dye has been reported as probe for local permittivity in polymers, in
Current understanding and biotechnological application of the bacterial diterpene synthase CotB2
Beilstein J. Org. Chem. 2019, 15, 2355–2368, doi:10.3762/bjoc.15.228
- date, CotB2 represents the best studied bacterial diterpene synthase. Its reaction mechanism has been addressed by isoptope labeling, targeted mutagenesis and theoretical computations in the gas phase, as well as full enzyme molecular dynamic simulations. By X-ray crystallography different snapshots of
- , antibiotic, neuroprotective and even insecticidal activities, which makes these compounds high-value commercial targets for the chemical and pharmaceutical industry [9][10]. Structural diversity of diterpenes is created by the terpene synthase (TPS) enzyme family, which use acyclic isoprenoid precursors to
- engineering to optimize product ratios or to alter the native product portfolio of the enzyme [9][26][27]. Furthermore, production by engineered microorganisms considerably reduces the cost compared to total chemical synthesis or extraction from natural sources, since the target compounds are produced from
Isolation and biosynthesis of an unsaturated fatty acid with unusual methylation pattern from a coral-associated bacterium Microbulbifer sp.
Beilstein J. Org. Chem. 2019, 15, 2327–2332, doi:10.3762/bjoc.15.225
- methyltransferase, followed by 1,2-hydride shift and deprotonation, and a subsequent reduction of the exo-methylene intermediate gives rise to a methyl group (Scheme 2) [18]. The presence of the exo-methylene intermediate was experimentally proved but the enzyme responsible for the double bond reduction has not
Harnessing enzyme plasticity for the synthesis of oxygenated sesquiterpenoids
Beilstein J. Org. Chem. 2019, 15, 2184–2190, doi:10.3762/bjoc.15.215
- engineering; terpenes; Introduction Amorphadiene synthase (ADS) from Artemisia annua is a key enzyme involved in the biosynthesis of the antimalarial sesquiterpene drug artemisinin (1) [1][2][3][4]. ADS catalyses the Mg2+-dependent conversion of farnesyl diphosphate (FDP, 2) to amorpha-4,11-diene (3) with
- as anchimeric assistance is hampered by unknowns such as the conformation of binding to the enzyme and what effect the extra bulk of the substituents has upon the results observed, but nevertheless such empirical results will accumulate to inform future investigations. This reversal of the
Azologization and repurposing of a hetero-stilbene-based kinase inhibitor: towards the design of photoswitchable sirtuin inhibitors
Beilstein J. Org. Chem. 2019, 15, 2170–2183, doi:10.3762/bjoc.15.214
- in their catalytic core domains, many isotype selective inhibitors have been developed in recent years [39][40][41][42][43][44][45]. In the case of Sirt2 it was shown that appropriate ligand binding can induce conformational changes of the enzyme, revealing a so-called selectivity pocket, which
- methylation was intended to be examined. For UV–vis spectroscopy 50 µM solutions in 5% DMSO (v/v) in enzyme assay buffer were used, as this reflects the enzyme assay conditions. However, for LC-HRMS and NMR analysis, a higher concentration of 10 mM in methanol was necessary to receive reliable chromatograms
- enzyme assay. The long irradiation periods that were necessary to obtain significant amounts of the (Z)-isomers did not permit switching of the inhibitors in the enzyme assay mixture, as the fluorescent substrate and the enzyme would be harmed by long-term UV radiation. We envisioned to replace the
Characterization of two new degradation products of atorvastatin calcium formed upon treatment with strong acids
Beilstein J. Org. Chem. 2019, 15, 2085–2091, doi:10.3762/bjoc.15.206
- , Germany 10.3762/bjoc.15.206 Abstract Atorvastatin calcium (Lipitor®, Sortis®) is a well-established cholesterol synthesis enzyme (CSE) inhibitor commonly used in the therapy of hypercholesterolemia. This drug is known to be sensitive to acid treatment, but only little data has been published on the
Genome mining in Trichoderma viride J1-030: discovery and identification of novel sesquiterpene synthase and its products
Beilstein J. Org. Chem. 2019, 15, 2052–2058, doi:10.3762/bjoc.15.202
- -overexpressing S. cerevisiae as a platform (Figure 1). By the heterologous expression of predicted terpene synthases from the genome of T. viride, an unknown sesquiterpene synthase was identified and characterised. Furthermore, a new compound produced by this enzyme and its esterified product were detected and
- synthase well-identified with products characterised in T. viride. In vitro analysis of Tvi09626 function To confirm the function of the candidate enzyme, the DNA sequence of Tvi09626 was amplified by touchdown PCR from the T. viride genome. The gene fragment was cloned into a pET28a (+) vector to
- Mg2+ or added EDTA (2.5 mM), compound 1 cannot be detected (Figure 5). This assay demonstrated that Tvi09626 was a Mg2+-dependent sesquiterpene synthase. In a kinetics analysis, the turnover rate (kcat) of the enzyme with FPP was (15 ± 0.3) × 10−2, which is similar to those of omp6 and omp7. Its
Isolation and characterisation of irinans, androstane-type withanolides from Physalis peruviana L.
Beilstein J. Org. Chem. 2019, 15, 2003–2012, doi:10.3762/bjoc.15.196
- characteristic of Physalis species. The biosynthesis of androstanes in mammals requires three enzymatic steps starting from cholesterol (9, Figure 3B) [27]. Cholesterol (9) is converted to pregnenolone (10) by the cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc), which cleaves the C20–C22 bond
- without the lactone side chain. We therefore propose that the side-chain cleavage enzyme in withanolide biosynthesis acts at a late stage, using common pathway end products such as 4ß-hydroxywithanolide E (1) as its substrates. Two mechanisms are conceivable for this transformation (Figure 3C): A non
- -oxidative Grob fragmentation could make use of a push–pull mechanism between C-17 and C-22, building on acid–base catalysis. Alternatively, an enzyme could cleave the C17–C20 diol oxidatively. Several P450 enzymes have been reported to be capable of cleaving diols, presumably via a ferric peroxo
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