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Search for "enzyme" in Full Text gives 553 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Synthetic strategies for the preparation of γ-phostams: 1,2-azaphospholidine 2-oxides and 1,2-azaphospholine 2-oxides
Beilstein J. Org. Chem. 2022, 18, 889–915, doi:10.3762/bjoc.18.90
- -azaphospholidine-5-carboxylate 2-oxide (69) was sensible to glutaminase, an enzyme that could ring-open 1,2-azaphospholidine-5-carboxylate 2-oxides (Scheme 12) [32]. Griffiths and co-workers mentioned the synthesis of dimethyl (2-methoxy-1,3-dimethyl-2-oxido-1,3-dihydrobenzo[d][1,2]azaphosphol-3-yl)phosphonate (71
Synthesis and HDAC inhibitory activity of pyrimidine-based hydroxamic acids
Beilstein J. Org. Chem. 2022, 18, 837–844, doi:10.3762/bjoc.18.84
- characterization and analytical data; HDAC enzyme activity assay; references; NMR spectra. Acknowledgements The authors thank Mr. M. Malikenas for recording the HRMS. Results of the investigation were presented as part of a report on the 16th international conference of the Lithuanian Chemical Society “Chemistry
The stereochemical course of 2-methylisoborneol biosynthesis
Beilstein J. Org. Chem. 2022, 18, 818–824, doi:10.3762/bjoc.18.82
- 2-methylisoborneol from (S)-2-Me-LPP may be explained by isomerization to 2-Me-GPP and then to (R)-2-Me-LPP. Keywords: biosynthesis; enantioselective synthesis; enzyme mechanisms; gas chromatography; terpenoids; Introduction After its first discovery from Streptomyces [1][2], it has been
- enriched 2-Me-LPP with 2-MIBS The enantiomerically enriched substrates (R)- and (S)-2-Me-LPP were incubated with purified 2MIBS (Figure S2 in Supporting Information File 1), followed by extraction of the enzyme reactions with hexane and GC/MS analysis of the obtained products (Figure S3, Table S1 in
- Supporting Information File 1). All compounds were identified from their EI mass spectra and retention indices in comparison to synthetic standards [29]. The substrate (R)-2-Me-LPP gave high yields of compound 1 (62% of total enzyme products in GC), besides 2-methylenebornane (10, 21%) and small amounts of 2
Synthesis of odorants in flow and their applications in perfumery
Beilstein J. Org. Chem. 2022, 18, 754–768, doi:10.3762/bjoc.18.76
- min isoamyl acetate (10) is obtained in 59% yield according to GC analysis [26]. Related methods for the enzyme-catalyzed acetylation of isoamyl alcohol (9) have been developed utilizing biphasic systems, supercritical carbon dioxide as a solvent, or packed-bed reactors with immobilized enzymes [27
- 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
- ) to (+)-nootkatone (8) under catalyst and solvent-free conditions in a segmented flow. Enzyme-catalyzed acetylation of isoamyl alcohol (9) in a biphasic n-heptane/water mixture utilizing a CorningTM Low Flow reactor. Esterification of alcohols by transesterification, catalyzed by immobilized
Identification of the new prenyltransferase Ubi-297 from marine bacteria and elucidation of its substrate specificity
Beilstein J. Org. Chem. 2022, 18, 722–731, doi:10.3762/bjoc.18.72
- -like acceptor compounds and farnesyl pyrophosphate (FPP) as most likely substrates for Ubi-297 (Maribacter sp. MS6). Thus, the 1st membrane faction containing membrane-bound UbiA-297 was subjected to an enzyme assay with farnesyl pyrophosphate (FPP) and different aromatic acceptor substrates in the
- the most favored substrate amongst the tested panel. Thus, we shortly investigated different reaction parameters using 8-HQA and FPP as substrates. First, we compared the enzyme activity of crude protein fractions directly obtained from cell lysate and enriched UbiA-297 fractions (Figure 6). As
- in pET28 vector (BioCAT GmbH) and transformed into E. coli BL21 for heterologous expression. Additionally, a modified ubiA-297(R145A) gene was synthesized and cloned into a pET28 vector (BioCAT GmbH) yielding pET28-297(R145A) for heterologous expression. Preparation of enzyme extracts and protein
Structural basis for endoperoxide-forming oxygenases
Beilstein J. Org. Chem. 2022, 18, 707–721, doi:10.3762/bjoc.18.71
- endoperoxygenase NvfI. Keywords: biosynthesis; endoperoxide; enzyme; natural products; X-ray crystallography; Introduction Endoperoxide-containing compounds form a large group of natural products with cyclic peroxide structures [1][2][3][4][5]. These compounds are widely distributed in nature, and many
- cyclooxygenases, FtmOx1, and NvfI. Review COX: Heme-dependent cyclooxygenases in the biosynthesis of prostaglandins Enzyme reaction of COXs The cyclooxygenases are the best studied and understood oxygenases among the mammalian oxygenases [29][30]. Mammals have two cyclooxygenase isoforms, COX-1 and COX-2 [31][32
- are well conserved. While COX-1 is a constitutive enzyme present in most tissues, COX-2 is an isoenzyme induced in response to tumor promoters, growth factors, and cytokines [38][39][40]. Therefore, many COX-2 selective inhibitors are clinically used for treatments of inflammation, cancers, and pain
Shift of the reaction equilibrium at high pressure in the continuous synthesis of neuraminic acid
Beilstein J. Org. Chem. 2022, 18, 567–579, doi:10.3762/bjoc.18.59
- for the aldolase from 108 to 42 mM and 91 to 37 mM, respectively. Keywords: aldolase; continuous fixed-bed reactor; enzyme; epimerase; GlcNAc; high pressure; immobilization; ManNAc; Neu5Ac; pyruvate; Introduction In times of a pandemic, the importance of substances to enhance the human immune system
- heparinus and the aldolase from Escherichia coli K12 were produced in E. coli BL21(DE3). Both enzymes were purified and immobilized on different carriers to find for each enzyme the best choice for a stable and active enzyme preparation when applied under high pressure in continuous operation. For screening
- purposes, six different carriers were used to immobilize the epimerase and aldolase (Table 1). The carriers differ in their properties (size, hydrophobicity, binding type, and porosity). The quality of immobilization was evaluated in terms of enzyme loading, activity, and reusability in repetitive batch
Terpenoids from Glechoma hederacea var. longituba and their biological activities
Beilstein J. Org. Chem. 2022, 18, 555–566, doi:10.3762/bjoc.18.58
- spectrum of 1S,4S,5R,8S,10R-(1a). Finally, the ᴅ-glucopyranosyl moiety was identified by GC–MS analysis of a chiral derivatization product of the sugar obtained by enzyme hydrolysis of 1 [9][10]. The retention time of glucopyranose (11.3 min) corresponded to that of the standard ᴅ-glucopyranose (11.3 min
- 3C). The experimental ECD spectrum of 2 showed a negative Cotton effect at 233 nm and positive Cotton effects at 217 and 257 nm, which showed a similarity with those of calculated ECD spectrum of 1R,4R,5S,6S,8S,10S-(ent-2a). Enzyme hydrolysis and following sugar identification were performed using
- configuration of 3 was confirmed by comparing the calculated ECD spectrum of 3a (aglycone of 3) with the experimental ECD spectrum of 3. The experimental ECD of 3 displayed positive Cotton effects at 217 and 243 nm, which was similar to those of 1R,4R,5S,6S,10S-(3a) (Figure 4B). Enzyme hydrolysis and sugar
Bioinspired tetraamino-bisthiourea chiral macrocycles in catalyzing decarboxylative Mannich reactions
Beilstein J. Org. Chem. 2022, 18, 486–496, doi:10.3762/bjoc.18.51
- ][10][11][12][13][14]. Among which, macrocyclic compounds have attracted extensive attentions due to their enzyme-mimicking cavity and preorganized binding sites [4][6][15][16]. Various macrocyclic compounds including the privileged scaffolds like cyclodextrins [17][18][19], calixarenes [20][21][22][23
Amamistatins isolated from Nocardia altamirensis
Beilstein J. Org. Chem. 2022, 18, 360–367, doi:10.3762/bjoc.18.40
- +). This feature makes iron very useful as an enzyme cofactor for the shuffling of electrons. As a consequence of this, the transition metal is involved in many fundamental biological processes, such as respiration, photosynthesis, or nitrogen fixation [1]. In order to achieve iron homeostasis, organisms
A resorcin[4]arene hexameric capsule as a supramolecular catalyst in elimination and isomerization reactions
Beilstein J. Org. Chem. 2022, 18, 337–349, doi:10.3762/bjoc.18.38
- the active site of the enzyme. Once bound, substrate activation is carried out by specific amino acid side chains that adorn the inner surface of the cavity by means of a combination of covalent and/or weak intermolecular interactions leading to the stabilization of intermediate species and transition
Site-selective reactions mediated by molecular containers
Beilstein J. Org. Chem. 2022, 18, 309–324, doi:10.3762/bjoc.18.35
- , and even emergence of new reaction pathways [19][20][21][22][23][24]. To simulate the aqueous environment of enzyme-catalyzed physiological transformations, researchers seek to design and synthesize supramolecular hosts in a water-soluble way. The ionic and polyol forms of them would provide good
- . Review Cycloaddition/addition Cycloaddition reactions have long been applied to molecular container-mediated enzyme-mimicking transformations [27][31][32][33], and the Fujita group has done pioneering research works in this direction [27][34]. In 2006, the authors reported unique Diels–Alder reactions of
- molecules orienting precisely fixed towards the active site of the enzyme through multiple noncovalent interactions [68][69]. Inspired by the magical ability of the enzyme’s receptor site to act on the substrate with fixed orientation, the Breslow group has done a lot of leading works [25][26] utilizing
New efficient synthesis of polysubstituted 3,4-dihydroquinazolines and 4H-3,1-benzothiazines through a Passerini/Staudinger/aza-Wittig/addition/nucleophilic substitution sequence
Beilstein J. Org. Chem. 2022, 18, 286–292, doi:10.3762/bjoc.18.32
- protein cleaving enzyme 1 (BACE-1) inhibitive [6], and cholinesterase enzyme inhibitive activities [7]. The 3,4-dihydroquinazoline skeleton also exists in some natural products such as vasicine and vasicoline [8]. Some 4H-3,1-benzothiazine derivatives have also received attention due to their good
Anomeric 1,2,3-triazole-linked sialic acid derivatives show selective inhibition towards a bacterial neuraminidase over a trypanosome trans-sialidase
Beilstein J. Org. Chem. 2022, 18, 208–216, doi:10.3762/bjoc.18.24
- and purity (qualitative assessment based on the NMR analysis) without further purification. Enzyme inhibition assays The inhibitory activities of compounds 3a–h toward TcTS and neuraminidase were assessed by a continuous fluorimetric assay [34], which is based on the residual hydrolase activity of
- described by Neres and co-workers [34]. Briefly, TcTS assay was performed in duplicate in 96-well plates containing 200 mM phosphate buffer solution pH 7 (20 μL), 0.8 mg/mL recombinant enzyme (20 μL), 5 mM lactose (20 μL) and 5 mM inhibitor (20 μL) solutions. This mixture was kept for 10 min at 25 °C
Synthesis and late stage modifications of Cyl derivatives
Beilstein J. Org. Chem. 2022, 18, 174–181, doi:10.3762/bjoc.18.19
- ]. Three of these enzyme classes (I, II, and IV) contain Zn2+ within the active site, and therefore these enzymes can be affected by typical Zn2+-binding HDAC inhibitors. In cellular systems, an acetylated lysine of a histone is entering the cavity of the active site and gets coordinated to Zn2
Synthesis and bioactivity of pyrrole-conjugated phosphopeptides
Beilstein J. Org. Chem. 2022, 18, 159–166, doi:10.3762/bjoc.18.17
- controlling cell fate. Keywords: cells; enzyme; N-terminal; peptides; pyrroles; self-assembly; Introduction Biomacromolecular assemblies have received considerable attention recently in the field of biomaterials [1][2][3][4][5][6][7], among which peptides are of particular interest because of their unique
- ][11], collagen mimic [12], antibacterial [13][14], biomineralization [15][16], mimicry of amyloids [17], cell cultures [18], and tissue engineering [19]. Particularly, the use of enzyme-instructed self-assembly (EISA) [20][21] of peptide assemblies has expanded the applications of peptide assemblies
- useful insights for the development of phosphopeptide derivatives as enzyme substrates for controlling cell fate. Results and Discussion Molecular design As illustrated in Scheme 1, the phosphopeptide (Nap-ffpy, 1) that inhibits HeLa cells consists of three segments, naphthylacetyl (Nap) at the N
Ready access to 7,8-dihydroindolo[2,3-d][1]benzazepine-6(5H)-one scaffold and analogues via early-stage Fischer ring-closure reaction
Beilstein J. Org. Chem. 2022, 18, 143–151, doi:10.3762/bjoc.18.15
- challenge and practical synthesis is still missing in the literature. Its accessibility may enrich the arsenal of available tools for enzyme inhibitor design by increasing the number of hydrogen bonding donor and acceptor groups at the same side of the backbone, which may result in a tight binding with
- enzyme active sites and/or improved selectivity [7]. One of the main drawbacks of paullones is their poor aqueous solubility. Therefore, in an attempt to overcome this shortcoming, the paullone backbone A was decorated with functional groups and coordinated to metal ions. Ruthenium(II), osmium(II), and
1,2-Naphthoquinone-4-sulfonic acid salts in organic synthesis
Beilstein J. Org. Chem. 2022, 18, 53–69, doi:10.3762/bjoc.18.5
- evaluated against their antioxidant activity and exhibited promising activity. Protein tyrosine phosphatase 1B (PTP1B) is essential in the dephosphorylation of the activated insulin receptor, and inhibition of this enzyme would be an excellent strategy for the treatment of type 2 diabetes. Ahn and co
- enzyme human carboxylesterase (hCE1) that cleaves carboxylic esters. This enzyme functions in the detoxification metabolism of carcinogenic and mutagenic organic compounds, converting them into nontoxic metabolites. This compound served as inspiration for Hatfield and co-workers [84], who proposed the
The enzyme mechanism of patchoulol synthase
Beilstein J. Org. Chem. 2022, 18, 13–24, doi:10.3762/bjoc.18.2
- calculations; enzyme mechanisms; isotopes; terpenes; Introduction Patchouli oil, the essential oil of the shrub Pogostemon cablin, has a pleasant woody odour and is of high economic value for the perfumery and cosmetics industries. It is mainly composed of sesquiterpenes with patchoulol as the main compound
- compound 3 and several biogenetically related terpene hydrocarbons including α-patchoulene (4), β-patchoulene (5), α-bulnesene (6) and α-guaiene (7) (Figure 1) [7]. The enzyme was subsequently made available by cDNA gene cloning, revealing germacrene A (8), α-humulene (9), (E)-β-caryophyllene (10
- reported, which was explained by an unusual intramolecular deuterium transfer. Herein, the deuteron is released from (2-2H)-J in the deprotonation step to 5 (or other enzyme products losing the same hydrogen in the terminal deprotonation). Deprotonation of (2-2H)-H was suggested to produce the unknown
Peptide stapling by late-stage Suzuki–Miyaura cross-coupling
Beilstein J. Org. Chem. 2022, 18, 1–12, doi:10.3762/bjoc.18.1
- by side chain cross-linking of bromotryptophan and an organoboron moiety. Bromotryptophans are accessible by enzymatic bromination utilising cross-linked enzyme aggregates (combiCLEAs) containing an FAD-dependent tryptophan halogenase, a flavin reductase and an alcohol dehydrogenase [73][74]. For
Synthetic strategies toward 1,3-oxathiolane nucleoside analogues
Beilstein J. Org. Chem. 2021, 17, 2680–2715, doi:10.3762/bjoc.17.182
- counterparts during DNA or RNA synthesis, a biological role that is crucial for cellular reproduction [2]. Most of the drugs that are incorporated in the viral DNA upon phosphorylation in vivo block the DNA polymerase enzyme. However, DNA polymerase recognizes 2’,3’-dideoxynucleosides as substrates, which are
- nucleic acid components. Therefore, it was assumed until recently that effective inhibition of the metabolic enzyme is only possible by ᴅ-nucleoside analogues, which have the stereochemistry of natural nucleosides. This was proved to be untrue when the antiviral activity of 1,3-oxathiolane nucleosides
- manner was reported by Chu et al. [22]. Choi et al. [23] produced the 5-fluoro-substituted analogue of a 1,3-oxathiolane nucleoside as a racemic mixture, and the enantiomers were separated using pig liver esterase (PLE) enzyme, which resulted in 5’-butyroyl ester derivatives. They further explained the
α-Ketol and α-iminol rearrangements in synthetic organic and biosynthetic reactions
Beilstein J. Org. Chem. 2021, 17, 2570–2584, doi:10.3762/bjoc.17.172
- eventually becomes isoleucine (Figure 14a). The enzyme catalyzes two consecutive reactions: an α-ketol rearrangement to generate a 3-hydroxy-2-ketoacid intermediate 61, followed by NADPH-dependent reduction to the dihydroxylated product 62 [18]. Interestingly, another reductoisomerase known as 1-deoxy-ᴅ
- 64 (Figure 14b) [20][21]. The other enzyme believed to catalyze an α-ketol rearrangement is AuaG, which is a monooxygenase that uses FAD and molecular oxygen to convert aurachin C (66) to 69 (Figure 14c) [22]. Subsequent reduction and dehydration by AuaH produces aurachin B (71). While the above are
- synthesis of (±)-securinine (54) and (±)-allosecurinine (55). Enzyme-catalyzed α-ketol rearrangements. a) Ketol-acid reductoisomerase (KAR) catalyzes the rearrangement of (2S)-acetolactate (65, R = Me) or (2S)-acetohydroxybutyrate (65, R = Et) to 66, followed by reduction by NADPH to 67. b) Despite the
Cryogels: recent applications in 3D-bioprinting, injectable cryogels, drug delivery, and wound healing
Beilstein J. Org. Chem. 2021, 17, 2553–2569, doi:10.3762/bjoc.17.171
- during degradation of cryogels, the walls of the cryogel decrease in thickness and are in some cases broken. This analysis was made for enzyme-degraded cryogels, so it is unclear whether the process is likely to occur for cryogels degraded by other mechanisms such as disulphide cleavage [30][31] and
Targeting active site residues and structural anchoring positions in terpene synthases
Beilstein J. Org. Chem. 2021, 17, 2441–2449, doi:10.3762/bjoc.17.161
- are otherwise highly conserved. Site-directed mutagenesis experiments for these residues are reported that showed different effects, resulting in some cases in an improved catalytic activity, but in other cases in a loss of enzyme function. For other enzyme variants a functional switch was observed
- , turning SmTS1 from a sesterterpene into a diterpene synthase. This article gives rational explanations for these findings that may generally allow for protein engineering of other terpene synthases to improve their catalytic efficiency or to change their functions. Keywords: biosynthesis; enzyme
- from Streptomyces mobaraensis (SmTS1) represents the first identified type I sesterterpene synthase (StTPS) from bacteria [16]. This enzyme converts GFPP into multiple products seven of which could be isolated and structurally characterised as sestermobaraenes A–F (1–6) and sestermobaraol (7) (Figure 2
Strategies for the synthesis of brevipolides
Beilstein J. Org. Chem. 2021, 17, 2399–2416, doi:10.3762/bjoc.17.157
- , C5’S, and C6’S. Most brevipolide members exhibited cytotoxicity against various targets, including human colon, breast, laryngeal, cervix, prostate, and nasopharyngeal cancer cell lines with ED50 and IC50 values ranged in micromolar order [1][4][12]. One member showed activity in an enzyme-based
- ]. These seven compounds, 1–7, were also evaluated for enzyme-based ELISA NF-κB and proteasome inhibition assays (Table 2, entries 1–7), but only brevipolide G (7) and brevipolide C (3) showed significant activities with ED50 values of 15.3 and 38.0 μM, respectively (Table 2, entries 7 and 3) [4]. Lastly
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