Cytochrome P450 monooxygenase-mediated tailoring of triterpenoids and steroids in plants

• Karan Malhotra and
• Jakob Franke

Beilstein J. Org. Chem. 2022, 18, 1289–1310, doi:10.3762/bjoc.18.135

• four CYPs could produce stigmasterol from β-sitosterol (2) in enzyme assays performed in vitro. However, Arabidopsis CYP710A2 showed substrate flexibility towards campesterol (1) epimers and could also produce brassicasterol from 24-epicampesterol in vitro. Enzymes of the CYP51G subfamily (CYP51 clan

• our review provides a good starting point for such further studies. Enzyme function of cytochrome P450 monooxygenases (CYPs). A) Typical net reaction of CYPs, resulting in hydroxylation of a substrate. As monooxygenases, CYPs catalyse transfer of only one oxygen atom from molecular oxygen to their

Make or break: the thermodynamic equilibrium of polyphosphate kinase-catalysed reactions

• Michael Keppler,
• Sandra Moser,
• Henning J. Jessen,
• Christoph Held and
• Jennifer N. Andexer

Beilstein J. Org. Chem. 2022, 18, 1278–1288, doi:10.3762/bjoc.18.134

• living organism investigated [1][2][3]. In 1956, Kornberg described the first polyP kinase (PPK) in Escherichia coli catalysing adenosine 5’-triphosphate (ATP)-dependent synthesis of polyP (Figure 2a) [4]. The enzyme was reclassified as family-1 PPK (PPK1) when a structurally different PPK (family-2

• model enzymes for PPK1 and PPK2 [9][10]. From a structure perspective, PPK1 enzymes form tetramers in solution with a mass of approximately 80 kDa for the monomer (Figure 2b). Although not being an integral membrane protein, the enzyme is described to be membrane-associated [11][12][13]. The phosphate

• transfer likely proceeds via formation of a phospho-enzyme intermediate (Figure 2d). Two essential histidine residues for autophosphorylation were identified by mutagenesis experiments [9][13][14]. Variants carrying mutations at these histidine residues lost the ability to synthesise polyP or ATP in vitro

Enzymes in biosynthesis

• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 1131–1132, doi:10.3762/bjoc.18.116

• proceed through multistep cationic cascade reactions and usually produce a polycyclic terpene hydrocarbon or alcohol with multiple stereogenic centers. While these transformations require only a single enzyme, polyketide and nonribosomal peptide biosyntheses are catalyzed by megasynthases that follow an

• assembly line logic, with individual domains for each single step [2]. Furthermore, the domains are organized into modules, each of which is responsible for the incorporation of one extender unit into the growing polyketide or peptide chain. With our knowledge today, the function of these large enzyme

• products, nature has evolved a large number of enzyme classes for more specific transformations, including cytochromes P450 or α-ketoglutarate-dependent dioxygenases for late-stage oxidations and transferases for the attachment of sugar units, acyl, or methyl groups. Moreover, some enzymes can catalyze

A Streptomyces P450 enzyme dimerizes isoflavones from plants

• Run-Zhou Liu,
• Shanchong Chen and
• Lihan Zhang

Beilstein J. Org. Chem. 2022, 18, 1107–1115, doi:10.3762/bjoc.18.113

• challenging and often requires prefunctionalization of the substrate monomers, costly metal ligands, or tedious protection–deprotection steps [6][7][8][9]. With the advance of biosynthetic studies on natural products, a number of enzyme classes that are responsible for the dimer formation have been identified

• reactions (Figure S1, Supporting Information File 1). Due to the high reaction selectivity that the enzyme active site offers, these enzymes provide biocatalytic means for the biaryl linkage formation, and recent enzyme engineering efforts also demonstrated selective and efficient production of unnatural

• dimers or cross-coupling products, starting from simple monomers [17][18][19]. Nevertheless, our knowledge of enzyme-mediated dimerization is still limited in contrast to the numerous reported dimeric natural products. Phenol coupling in plant polyphenol biosynthesis is one of the earliest documented

New azodyrecins identified by a genome mining-directed reactivity-based screening

• Atina Rizkiya Choirunnisa,
• Kuga Arima,
• Yo Abe,
• Noritaka Kagaya,
• Kei Kudo,
• Hikaru Suenaga,
• Junko Hashimoto,
• Manabu Fujie,
• Noriyuki Satoh,
• Kazuo Shin-ya,
• Kenichi Matsuda and
• Toshiyuki Wakimoto

Beilstein J. Org. Chem. 2022, 18, 1017–1025, doi:10.3762/bjoc.18.102

• enzyme VlmA [18]. This intermediate is hypothesized to be transformed into the azoxy bond-containing intermediate via an intramolecular rearrangement accompanied by a concomitant oxidation [18]. Although the exact mechanisms of azoxy bond formation remain unclear, VlmH and VlmA cooperate to biosynthesize

• the two-component flavin-dependent monooxygenase Ady3/Ady10, as in the valanimycin biosynthesis mediated by VlmH/VlmR [15][16][17]. The hydroxylamine would be conjugated to alanyl-tRNA to form an ester intermediate by the function of the tRNA-utilizing enzyme Ady7, which is homologous to VlmA. In

Isolation and biosynthesis of daturamycins from Streptomyces sp. KIB-H1544

• Yin Chen,
• Jinqiu Ren,
• Ruimin Yang,
• Jie Li,
• Sheng-Xiong Huang and
• Yijun Yan

Beilstein J. Org. Chem. 2022, 18, 1009–1016, doi:10.3762/bjoc.18.101

• ) HPLC analysis of the fermentation extracts of mutant S. sp. KIB-H1544-∆datA. (B) SDS-PAGE analysis of purified DatA (calculated molecular mass 101.8 kDa) and EchA (calculated molecular mass 105.4 kDa) protein. (C) HPLC analysis of in vitro enzyme reactions. Panel I, phenylpyruvic acid with boiled DatA

Understanding the competing pathways leading to hydropyrene and isoelisabethatriene

• Shani Zev,
• Marion Ringel,
• Ronja Driller,
• Bernhard Loll,
• Thomas Brück and
• Dan T. Major

Beilstein J. Org. Chem. 2022, 18, 972–978, doi:10.3762/bjoc.18.97

• . We show that there is a great thermodynamic preference for hydropyrene and hydropyrenol formation, and hence most likely in the synthesis of the isoelisabethatriene products kinetic control is at play. Keywords: diterpenes; enzyme mechanism; quantum mechanics; terpene synthases; thermodynamic and

• , having antibiotic and anti-inflammatory activities, respectively [4][5]. Unexpectedly, a single active site mutation, M75L, significantly shifts the product distribution and IE A becomes the dominant product (44%) in this enzyme variant [6]. As suggested by Rinkel et al., both routes (HP and IE routes

• isomerization is responsible for a slightly different substrate fold inside the active site, hence shifting the product distribution in favor of the IE products in certain enzyme variants rather than the HP products. Oxidation of IEs A and B by lipases results in the formation of the advanced pseudopterosin (P

Anti-inflammatory aromadendrane- and cadinane-type sesquiterpenoids from the South China Sea sponge Acanthella cavernosa

• Shou-Mao Shen,
• Qing Yang,
• Yi Zang,
• Jia Li,
• Xueting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 916–925, doi:10.3762/bjoc.18.91

• characterized the function of a P450 enzyme CYP76AH1 which was responsible for the formation of the aromatic ring of ferruginol in the biosynthesis pathway of tanshinones [34]. Hence, we proposed that the oxidation occurred on L to furnish the aromatic ring of calamenene (M) [29], followed by the hydroxylation

Synthetic strategies for the preparation of γ-phostams: 1,2-azaphospholidine 2-oxides and 1,2-azaphospholine 2-oxides

• Jiaxi Xu

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

• Virginija Jakubkiene,
• Gabrielius Ernis Valiulis,
• Markus Schweipert,
• Asta Zubriene,
• Daumantas Matulis,
• Franz-Josef Meyer-Almes and
• Sigitas Tumkevicius

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

• Binbin Gu,
• Anwei Hou and
• Jeroen S. Dickschat

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

• Merlin Kleoff,
• Paul Kiler and
• Philipp Heretsch

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

• Jamshid Amiri Moghaddam,
• Huijuan Guo,
• Karsten Willing,
• Thomas Wichard and
• Christine Beemelmanns

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

• Takahiro Mori and
• Ikuro Abe

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

• Jannis A. Reich,
• Miriam Aßmann,
• Kristin Hölting,
• Paul Bubenheim,
• Jürgen Kuballa and
• Andreas Liese

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

• Dong Hyun Kim,
• Song Lim Ham,
• Zahra Khan,
• Sun Yeou Kim,
• Sang Un Choi,
• Chung Sub Kim and
• Kang Ro Lee

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

• Hao Guo,
• Yu-Fei Ao,
• De-Xian Wang and
• Qi-Qiang Wang

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

• 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