Amamistatins isolated from Nocardia altamirensis

• Till Steinmetz,
• Wolf Hiller and
• Markus Nett

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

• Tommaso Lorenzetto,
• Fabrizio Fabris and
• Alessandro Scarso

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

• Rui Wang and
• Yang Yu

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

• Long Zhao,
• Mao-Lin Yang,
• Min Liu and
• Ming-Wu Ding

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

• Peterson de Andrade,
• Sanaz Ahmadipour and
• Robert A. Field

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

• Phil Servatius and
• Uli Kazmaier

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

• Qiuxin Zhang,
• Weiyi Tan and
• Bing Xu

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

• Irina Kuznetcova,
• Felix Bacher,
• Daniel Vegh,
• Hsiang-Yu Chuang and
• Vladimir B. Arion

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

• Ruan Carlos B. Ribeiro,
• Patricia G. Ferreira,
• Amanda de A. Borges,
• Luana da S. M. Forezi,
• Fernando de Carvalho da Silva and
• Vitor F. Ferreira

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

• Houchao Xu,
• Bernd Goldfuss,
• Gregor Schnakenburg and
• Jeroen S. Dickschat

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

• Hendrik Gruß,
• Rebecca C. Feiner,
• Ridhiwan Mseya,
• David C. Schröder,
• Michał Jewgiński,
• Kristian M. Müller,
• Rafał Latajka,
• Antoine Marion and
• Norbert Sewald

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

• 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

• 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

• Scott Benz and
• Andrew S. Murkin

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

• Luke O. Jones,
• Leah Williams,
• Tasmin Boam,
• Martin Kalmet,
• Chidubem Oguike and
• Fiona L. Hatton

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

• Anwei Hou and
• Jeroen S. Dickschat

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

• Yudhi D. Kurniawan and
• A'liyatur Rosyidah

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

Isolation and characterization of new phenolic siderophores with antimicrobial properties from Pseudomonas sp. UIAU-6B

• Emmanuel T. Oluwabusola,
• Olusoji O. Adebisi,
• Fernando Reyes,
• Kojo S. Acquah,
• Mercedes De La Cruz,
• Larry L. Mweetwa,
• Joy E. Rajakulendran,
• Digby F. Warner,
• Deng Hai,
• Rainer Ebel and
• Marcel Jaspars

Beilstein J. Org. Chem. 2021, 17, 2390–2398, doi:10.3762/bjoc.17.156

• , respectively (Figure 3). Biochemical studies show that histamine and phenethylamine moieties were produced from histidine and phenylalanine substrates by a decarboxylase enzyme [41][42][43]. Pseudomobactin A (4) was proposed logically to have formed through direct amination of the unstable salimethyloxazolinyl

Halides as versatile anions in asymmetric anion-binding organocatalysis

• Lukas Schifferer,
• Martin Stinglhamer,
• Kirandeep Kaur and
• Olga García Macheño

Beilstein J. Org. Chem. 2021, 17, 2270–2286, doi:10.3762/bjoc.17.145

• examples, and the advance of anion-binding-catalyzed strategies involving more complex H-bonding networks clearly highlight that it is indeed possible to mimic enzyme-like structures with small-molecule catalysts for asymmetric synthesis. Conclusion In the past two decades, tremendous advances in the field

(Phenylamino)pyrimidine-1,2,3-triazole derivatives as analogs of imatinib: searching for novel compounds against chronic myeloid leukemia

• Luiz Claudio Ferreira Pimentel,
• Lucas Villas Boas Hoelz,
• Henayle Fernandes Canzian,
• Frederico Silva Castelo Branco,
• Andressa Paula de Oliveira,
• Vinicius Rangel Campos,
• Floriano Paes Silva Júnior,
• Rafael Ferreira Dantas,
• Jackson Antônio Lamounier Camargos Resende,
• Anna Claudia Cunha,
• Nubia Boechat and
• Mônica Macedo Bastos

Beilstein J. Org. Chem. 2021, 17, 2260–2269, doi:10.3762/bjoc.17.144

• 10.3762/bjoc.17.144 Abstract The enzyme tyrosine kinase BCR-Abl-1 is the main molecular target in the treatment of chronic myeloid leukemia and can be competitively inhibited by tyrosine kinase inhibitors such as imatinib. New potential competitive inhibitors were synthesized using the (phenylamino

• -4 of the triazole nucleus. All compounds were evaluated for their inhibitory activities against a chronic myeloid leukemia cell line (K562) that expresses the enzyme tyrosine kinase BCR-Abl-1 and against healthy cells (WSS-1) to observe their selectivity. Three compounds showed promising results

• the transduction of signals; these processes induce cell apoptosis [8][9]. As mutations in the BCR-Abl-1 enzyme domain can occur, cases of resistance have emerged in the treatment with TKIs, compromising its effectiveness [10][11]. In continuation of the work by our group to develop new imatinib

Constrained thermoresponsive polymers – new insights into fundamentals and applications

• Patricia Flemming,
• Alexander S. Münch,
• Andreas Fery and
• Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

• (LG, e.g., phosphate, fluoride, nucleotide) are polymerized by the enzyme to form the desired polysaccharide (Figure 1A). Several classes of enzymes are available, including hydrolases, phosphorylases, sucrases, glycosyltransferases, and glycosynthases [19][20][21][22]. An excellent overview of the

• enzymes available for polysaccharide synthesis and their mode of action was recently published [11]. Despite the numerous advantages of this approach, limited enzyme availability as well as their high specificity narrowed the substrate scope. Generally, the highly specific enzyme reactive site tolerates

• polymerization of cellobiose fluoride 1 was achieved using a cellulase produced from Trichoderma viride (Scheme 1A). The DP of the acetylated product was shown to be at least 22. Using a purified version of this enzyme, it was possible to obtain a synthetic analogue of Cellulose I [64]. A rough control of DPs

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

• in good yields (Scheme 39C). The authors used the same methodology to synthesize two 4H-benzo[d][1,3]oxazin-4-one derivatives that act as inhibitors of two enzymes (compounds 130 and 131 in Scheme 39D). The first one is the enzyme C1r serine protease, involved in both inflammation and renal scarring

• [199], and the second one is the enzyme elastase, responsible for consuming elastine, leading to aging processes [200]. Beyond that, 4H-benzo[d][1,3]oxazin-4-one derivatives 126–129 have been studied as potential hypolipidemic drugs (Scheme 39A) [201]. Beyond the above-cited

Natural products in the predatory defence of the filamentous fungal pathogen Aspergillus fumigatus

• Jana M. Boysen,
• Nauman Saeed and
• Falk Hillmann

Beilstein J. Org. Chem. 2021, 17, 1814–1827, doi:10.3762/bjoc.17.124

• methionine aminopeptidase type-2 (MetAP-2) enzyme [129]. MetAP-2 is involved in cell proliferation, translation and post-translational modifications of nascent polypeptides and is therefore essential for cell viability [130][131]. Additionally, fumagillin is also known to be overproduced upon caspofungin

• with the prenylation of ʟ-tryptophan to dimethylallyltryptophan (DMAT). During several steps DMAT is converted to chanoclavine-I aldehyde, the last mutual intermediate. Branching into different pathways after this intermediate is mainly due to differences in the function of EasA, the enzyme catalysing

• hydroxylated and methylated to tryprostatin A. Oxidative closure of the ringstructure then results in fumitremorgin C. Further modification of the structure leads to fumitremorgin B and verruculogen, which shares the same pathway [97][160][161][162]. Which enzyme is responsible for the conversion of

A systems-based framework to computationally describe putative transcription factors and signaling pathways regulating glycan biosynthesis

• Theodore Groth,
• Rudiyanto Gunawan and
• Sriram Neelamegham

Beilstein J. Org. Chem. 2021, 17, 1712–1724, doi:10.3762/bjoc.17.119

• attached. In particular, such extensions may be initiated by members of the B4GALT family or B3GALNT2. Specific variants are noted on α-dystroglycans. 14) O-linked fucose: This pathway includes POFUT1, the enzyme responsible for the addition of fucose to Ser/Thr residues. MFNG, LFNG, and RFNG can attach

Volatile emission and biosynthesis in endophytic fungi colonizing black poplar leaves

• Christin Walther,
• Pamela Baumann,
• Katrin Luck,
• Beate Rothe,
• Peter H. W. Biedermann,
• Jonathan Gershenzon,
• Tobias G. Köllner and
• Sybille B. Unsicker

Beilstein J. Org. Chem. 2021, 17, 1698–1711, doi:10.3762/bjoc.17.118

• Cladosporium sp. emitted (E)-β-caryophyllene (1) in culture (Table 2, Figure 1). As this sesquiterpene is also a characteristic VOC in the constitutive and herbivore-induced blends of black poplar [57][58][59], we wanted to identify and characterize the responsible fungal terpene synthase, as this enzyme could

• sesquiterpene product was formed by each TPS: CxTPS1 produced (E,E)-α-farnesene (12) and CxTPS2 produced (E)-β-caryophyllene (1). With GGPP, no enzyme activity was recorded for CxTPS2, while CxTPS1 converted this substrate to (E,E)-β-springene (13) as the minor compound and major amounts of (E,E,E)-α-springene

• ). CxTPS1 was a multifunctional enzyme in vitro and produced the monoterpenes myrcene (9) and (E)-β-ocimene (10) from GPP, the sesquiterpene (E,E)-α-farnesene (12) from FPP, and the diterpenes (E,E)-β-springene (13) and (E,E,E)-α-springene (14) from GGPP. CxTPS2, in contrast, showed a narrower substrate